randomised cross-over simulation: Topics by Science.gov

Sample records for randomised cross-over simulation

Choosing appropriate analysis methods for cluster randomised cross-over trials with a binary outcome.

PubMed

Morgan, Katy E; Forbes, Andrew B; Keogh, Ruth H; Jairath, Vipul; Kahan, Brennan C

2017-01-30

In cluster randomised cross-over (CRXO) trials, clusters receive multiple treatments in a randomised sequence over time. In such trials, there is usual correlation between patients in the same cluster. In addition, within a cluster, patients in the same period may be more similar to each other than to patients in other periods. We demonstrate that it is necessary to account for these correlations in the analysis to obtain correct Type I error rates. We then use simulation to compare different methods of analysing a binary outcome from a two-period CRXO design. Our simulations demonstrated that hierarchical models without random effects for period-within-cluster, which do not account for any extra within-period correlation, performed poorly with greatly inflated Type I errors in many scenarios. In scenarios where extra within-period correlation was present, a hierarchical model with random effects for cluster and period-within-cluster only had correct Type I errors when there were large numbers of clusters; with small numbers of clusters, the error rate was inflated. We also found that generalised estimating equations did not give correct error rates in any scenarios considered. An unweighted cluster-level summary regression performed best overall, maintaining an error rate close to 5% for all scenarios, although it lost power when extra within-period correlation was present, especially for small numbers of clusters. Results from our simulation study show that it is important to model both levels of clustering in CRXO trials, and that any extra within-period correlation should be accounted for. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Minimum number of clusters and comparison of analysis methods for cross sectional stepped wedge cluster randomised trials with binary outcomes: A simulation study.

PubMed

Barker, Daniel; D'Este, Catherine; Campbell, Michael J; McElduff, Patrick

2017-03-09

Stepped wedge cluster randomised trials frequently involve a relatively small number of clusters. The most common frameworks used to analyse data from these types of trials are generalised estimating equations and generalised linear mixed models. A topic of much research into these methods has been their application to cluster randomised trial data and, in particular, the number of clusters required to make reasonable inferences about the intervention effect. However, for stepped wedge trials, which have been claimed by many researchers to have a statistical power advantage over the parallel cluster randomised trial, the minimum number of clusters required has not been investigated. We conducted a simulation study where we considered the most commonly used methods suggested in the literature to analyse cross-sectional stepped wedge cluster randomised trial data. We compared the per cent bias, the type I error rate and power of these methods in a stepped wedge trial setting with a binary outcome, where there are few clusters available and when the appropriate adjustment for a time trend is made, which by design may be confounding the intervention effect. We found that the generalised linear mixed modelling approach is the most consistent when few clusters are available. We also found that none of the common analysis methods for stepped wedge trials were both unbiased and maintained a 5% type I error rate when there were only three clusters. Of the commonly used analysis approaches, we recommend the generalised linear mixed model for small stepped wedge trials with binary outcomes. We also suggest that in a stepped wedge design with three steps, at least two clusters be randomised at each step, to ensure that the intervention effect estimator maintains the nominal 5% significance level and is also reasonably unbiased.
Effect of aggregation form on bioavailability of zeaxanthin in humans: a randomised cross-over study.

PubMed

Hempel, Judith; Fischer, Anja; Fischer, Monique; Högel, Josef; Bosy-Westphal, Anja; Carle, Reinhold; Schweiggert, Ralf M

2017-11-01

Carotenoid bioavailability from plant and animal food is highly variable depending on numerous factors such as the physical deposition form of carotenoids. As the carotenoid zeaxanthin is believed to play an important role in eye and brain health, we sought to compare the human bioavailability of an H-aggregated with that of a J-aggregated deposition form of zeaxanthin encapsulated into identical formulation matrices. A randomised two-way cross-over study with sixteen participants was designed to compare the post-prandial bioavailability of an H-aggregated zeaxanthin and a J-aggregated zeaxanthin dipalmitate formulation, both delivering 10 mg of free zeaxanthin. Carotenoid levels in TAG-rich lipoprotein fractions were analysed over 9·5 h after test meal consumption. Bioavailability from the J-aggregated formulation (AUC=55·9 nmol h/l) was 23 % higher than from the H-aggregated one (AUC=45·5 nmol h/l), although being only marginally significant (P=0·064). Furthermore, the same formulations were subjected to an internationally recognised in vitro digestion protocol to reveal potential strengths and weaknesses of simulated digestions. In agreement with our human study, liberation of zeaxanthin from the J-aggregated formulation into the simulated duodenal fluids was superior to that from the H-aggregated form. However, micellization rate (bioaccessibility) of the J-aggregated zeaxanthin dipalmitate was lower than that of the H-aggregated zeaxanthin, being contradictory to our in vivo results. An insufficient ester cleavage during simulated digestion was suggested to be the root cause for these observations. In brief, combining our in vitro and in vivo observations, the effect of the different aggregation forms on human bioavailability was lower than expected.
The Communicability of Graphical Alternatives to Tabular Displays of Statistical Simulation Studies

PubMed Central

Cook, Alex R.; Teo, Shanice W. L.

2011-01-01

Simulation studies are often used to assess the frequency properties and optimality of statistical methods. They are typically reported in tables, which may contain hundreds of figures to be contrasted over multiple dimensions. To assess the degree to which these tables are fit for purpose, we performed a randomised cross-over experiment in which statisticians were asked to extract information from (i) such a table sourced from the literature and (ii) a graphical adaptation designed by the authors, and were timed and assessed for accuracy. We developed hierarchical models accounting for differences between individuals of different experience levels (under- and post-graduate), within experience levels, and between different table-graph pairs. In our experiment, information could be extracted quicker and, for less experienced participants, more accurately from graphical presentations than tabular displays. We also performed a literature review to assess the prevalence of hard-to-interpret design features in tables of simulation studies in three popular statistics journals, finding that many are presented innumerately. We recommend simulation studies be presented in graphical form. PMID:22132184
The communicability of graphical alternatives to tabular displays of statistical simulation studies.

PubMed

Cook, Alex R; Teo, Shanice W L

2011-01-01

Simulation studies are often used to assess the frequency properties and optimality of statistical methods. They are typically reported in tables, which may contain hundreds of figures to be contrasted over multiple dimensions. To assess the degree to which these tables are fit for purpose, we performed a randomised cross-over experiment in which statisticians were asked to extract information from (i) such a table sourced from the literature and (ii) a graphical adaptation designed by the authors, and were timed and assessed for accuracy. We developed hierarchical models accounting for differences between individuals of different experience levels (under- and post-graduate), within experience levels, and between different table-graph pairs. In our experiment, information could be extracted quicker and, for less experienced participants, more accurately from graphical presentations than tabular displays. We also performed a literature review to assess the prevalence of hard-to-interpret design features in tables of simulation studies in three popular statistics journals, finding that many are presented innumerately. We recommend simulation studies be presented in graphical form.
A systematic examination of preoperative surgery warm-up routines.

PubMed

Pike, T W; Pathak, S; Mushtaq, F; Wilkie, R M; Mon-Williams, M; Lodge, J P A

2017-05-01

Recent evidence indicates that a preoperative warm-up is a potentially useful tool in facilitating performance. But what factors drive such improvements and how should a warm-up be implemented? In order to address these issues, we adopted a two-pronged approach: (1) we conducted a systematic review of the literature to identify existing studies utilising preoperative simulation techniques; (2) we performed task analysis to identify the constituent parts of effective warm-ups. We identified five randomised control trials, four randomised cross-over trials and four case series. The majority of these studies reviewed surgical performance following preoperative simulation relative to performance without simulation. Four studies reported outcome measures in real patients and the remainder reported simulated outcome measures. All but one of the studies found that preoperative simulation improves operative outcomes-but this improvement was not found across all measured parameters. While the reviewed studies had a number of methodological issues, the global data indicate that preoperative simulation has substantial potential to improve surgical performance. Analysis of the task characteristics of successful interventions indicated that the majority of these studies employed warm-ups that focused on the visual motor elements of surgery. However, there was no theoretical or empirical basis to inform the design of the intervention in any of these studies. There is an urgent need for a more rigorous approach to the development of "warm-up" routines if the potential value of preoperative simulation is to be understood and realised. We propose that such interventions need to be grounded in theory and empirical evidence on human motor performance.
An imbalance in cluster sizes does not lead to notable loss of power in cross-sectional, stepped-wedge cluster randomised trials with a continuous outcome.

PubMed

Kristunas, Caroline A; Smith, Karen L; Gray, Laura J

2017-03-07

The current methodology for sample size calculations for stepped-wedge cluster randomised trials (SW-CRTs) is based on the assumption of equal cluster sizes. However, as is often the case in cluster randomised trials (CRTs), the clusters in SW-CRTs are likely to vary in size, which in other designs of CRT leads to a reduction in power. The effect of an imbalance in cluster size on the power of SW-CRTs has not previously been reported, nor what an appropriate adjustment to the sample size calculation should be to allow for any imbalance. We aimed to assess the impact of an imbalance in cluster size on the power of a cross-sectional SW-CRT and recommend a method for calculating the sample size of a SW-CRT when there is an imbalance in cluster size. The effect of varying degrees of imbalance in cluster size on the power of SW-CRTs was investigated using simulations. The sample size was calculated using both the standard method and two proposed adjusted design effects (DEs), based on those suggested for CRTs with unequal cluster sizes. The data were analysed using generalised estimating equations with an exchangeable correlation matrix and robust standard errors. An imbalance in cluster size was not found to have a notable effect on the power of SW-CRTs. The two proposed adjusted DEs resulted in trials that were generally considerably over-powered. We recommend that the standard method of sample size calculation for SW-CRTs be used, provided that the assumptions of the method hold. However, it would be beneficial to investigate, through simulation, what effect the maximum likely amount of inequality in cluster sizes would be on the power of the trial and whether any inflation of the sample size would be required.
Use of an embedded, micro-randomised trial to investigate non-compliance in telehealth interventions.

PubMed

Law, Lisa M; Edirisinghe, Nuwani; Wason, James Ms

2016-08-01

Many types of telehealth interventions rely on activity from the patient in order to have a beneficial effect on their outcome. Remote monitoring systems require the patient to record regular measurements at home, for example, blood pressure, so clinicians can see whether the patient's health changes over time and intervene if necessary. A big problem in this type of intervention is non-compliance. Most telehealth trials report compliance rates, but they rarely compare compliance among various options of telehealth delivery, of which there may be many. Optimising telehealth delivery is vital for improving compliance and, therefore, clinical outcomes. We propose a trial design which investigates ways of improving compliance. For efficiency, this trial is embedded in a larger trial for evaluating clinical effectiveness. It employs a technique called micro-randomisation, where individual patients are randomised multiple times throughout the study. The aims of this article are (1) to verify whether the presence of an embedded secondary trial still allows valid analysis of the primary research and (2) to demonstrate the usefulness of the micro-randomisation technique for comparing compliance interventions. Simulation studies were used to simulate a large number of clinical trials, in which no embedded trial was used, a micro-randomised embedded trial was used, and a factorial embedded trial was used. Each simulation recorded the operating characteristics of the primary and secondary trials. We show that the type I error rate of the primary analysis was not affected by the presence of an embedded secondary trial. Furthermore, we show that micro-randomisation is superior to a factorial design as it reduces the variation caused by within-patient correlation. It therefore requires smaller sample sizes - our simulations showed a requirement of 128 patients for a micro-randomised trial versus 760 patients for a factorial design, in the presence of within-patient correlation. We believe that an embedded, micro-randomised trial is a feasible technique that can potentially be highly useful in telehealth trials. © The Author(s) 2016.
Sample size calculation for stepped wedge and other longitudinal cluster randomised trials.

PubMed

Hooper, Richard; Teerenstra, Steven; de Hoop, Esther; Eldridge, Sandra

2016-11-20

The sample size required for a cluster randomised trial is inflated compared with an individually randomised trial because outcomes of participants from the same cluster are correlated. Sample size calculations for longitudinal cluster randomised trials (including stepped wedge trials) need to take account of at least two levels of clustering: the clusters themselves and times within clusters. We derive formulae for sample size for repeated cross-section and closed cohort cluster randomised trials with normally distributed outcome measures, under a multilevel model allowing for variation between clusters and between times within clusters. Our formulae agree with those previously described for special cases such as crossover and analysis of covariance designs, although simulation suggests that the formulae could underestimate required sample size when the number of clusters is small. Whether using a formula or simulation, a sample size calculation requires estimates of nuisance parameters, which in our model include the intracluster correlation, cluster autocorrelation, and individual autocorrelation. A cluster autocorrelation less than 1 reflects a situation where individuals sampled from the same cluster at different times have less correlated outcomes than individuals sampled from the same cluster at the same time. Nuisance parameters could be estimated from time series obtained in similarly clustered settings with the same outcome measure, using analysis of variance to estimate variance components. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Combined caffeine and bright light reduces dangerous driving in sleep-deprived healthy volunteers: a pilot cross-over randomised controlled trial.

PubMed

Hartley, S L; Barbot, F; Machou, M; Lejaille, M; Moreau, B; Vaugier, I; Lofaso, F; Quera-Salva, M A

2013-06-01

To explore the effects of caffeine and bright light therapy on simulated nighttime driving in sleep-deprived healthy volunteers. Twelve male healthy volunteers aged 20 to 50 years participated in a randomized cross-over study of simulated nighttime driving at a sleep laboratory, followed by recovery sleep with polysomnography at home. The volunteers received variable combinations of caffeine 200mg (C+), caffeine placebo (C-), bright light 10,000 lux (L+), and bright light placebo<50 lux (L-), in four sessions (C+L+, C+L-, C-L+, C-L-), in random order with a wash-out period of 7 days. Treatments were given at 1 a.m. and testing was performed at 1:30 a.m., 3 a.m., 4 a.m., and 6 a.m. Lane drifting was the primary outcome measure. Other measures were reaction times, self-rated fatigue, sleepiness and recovery sleep. Without treatment, lane drifting increased throughout the night, and objective and subjective vigilance declined. Paired comparisons showed that lane drifting was significantly worse at 6 a.m. and at 4 a.m. than at 1:30 a.m. There was a global treatment effect on lane drifting. Lane drifting at 6 a.m. was significantly decreased with C+L+ compared to C-L-. Bright light therapy combined with caffeine administered at 1 a.m. decreased lane drifting by healthy volunteers during simulated nighttime driving. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Randomised controlled cross-over comparison of continuous positive airway pressure through the Hamilton Galileo ventilator with a Dräger CF 800 device.

PubMed

Sutton, P J; Perkins, C L; Giles, S P; McAuley, D F; Gao, F

2005-01-01

In this controlled, randomised cross-over trial on 26 intensive care patients, we compared the effects on haemodynamic and respiratory profiles of continuous positive airway pressure delivered through the Hamilton Galileo ventilator or a Drager CF 800 device. We also compared the nursing time saved using the two approaches when weaning patients from mechanical ventilation. We did not find significant differences in haemodynamics, respiratory rate, physiological dead space, oxygen saturation and carbon dioxide production between the continuous positive airway pressure generated by the Galileo and Drager machines. However, there was a 10-fold reduction in nursing time using the Galileo ventilator compared with the Drager generator. We conclude that continuous positive airway pressure delivered through the Galileo ventilator is as efficient as a Drager device but consumes less nursing time.
Gastrointestinal adverse events during methylphenidate treatment of children and adolescents with attention deficit hyperactivity disorder: A systematic review with meta-analysis and Trial Sequential Analysis of randomised clinical trials.

PubMed

Holmskov, Mathilde; Storebø, Ole Jakob; Moreira-Maia, Carlos R; Ramstad, Erica; Magnusson, Frederik Løgstrup; Krogh, Helle B; Groth, Camilla; Gillies, Donna; Zwi, Morris; Skoog, Maria; Gluud, Christian; Simonsen, Erik

2017-01-01

To study in more depth the relationship between type, dose, or duration of methylphenidate offered to children and adolescents with attention deficit hyperactivity disorder and their risks of gastrointestinal adverse events based on our Cochrane systematic review. We use data from our review including 185 randomised clinical trials. Randomised parallel-group trials and cross-over trials reporting gastrointestinal adverse events associated with methylphenidate were included. Data were extracted and quality assessed according to Cochrane guidelines. Data were summarised as risk ratios (RR) with 95% confidence intervals (CI) using the inverse variance method. Bias risks were assessed according to domains. Trial Sequential Analysis (TSA) was used to control random errors. Eighteen parallel group trials and 43 cross-over trials reported gastrointestinal adverse events. All trials were at high risk of bias. In parallel group trials, methylphenidate decreased appetite (RR 3.66, 95% CI 2.56 to 5.23) and weight (RR 3.89, 95% CI 1.43 to 10.59). In cross-over trials, methylphenidate increased abdominal pain (RR 1.61, 95% CI 1.27 to 2.04). We found no significant differences in the risk according to type, dose, or duration of administration. The required information size was achieved in three out of four outcomes. Methylphenidate increases the risks of decreased appetite, weight loss, and abdominal pain in children and adolescents with attention deficit hyperactivity disorder. No differences in the risks of gastrointestinal adverse events according to type, dose, or duration of administration were found.
Gastrointestinal adverse events during methylphenidate treatment of children and adolescents with attention deficit hyperactivity disorder: A systematic review with meta-analysis and Trial Sequential Analysis of randomised clinical trials

PubMed Central

Holmskov, Mathilde; Storebø, Ole Jakob; Moreira-Maia, Carlos R.; Ramstad, Erica; Magnusson, Frederik Løgstrup; Krogh, Helle B.; Groth, Camilla; Gillies, Donna; Zwi, Morris; Skoog, Maria; Gluud, Christian; Simonsen, Erik

2017-01-01

Objectives To study in more depth the relationship between type, dose, or duration of methylphenidate offered to children and adolescents with attention deficit hyperactivity disorder and their risks of gastrointestinal adverse events based on our Cochrane systematic review. Methods and findings We use data from our review including 185 randomised clinical trials. Randomised parallel-group trials and cross-over trials reporting gastrointestinal adverse events associated with methylphenidate were included. Data were extracted and quality assessed according to Cochrane guidelines. Data were summarised as risk ratios (RR) with 95% confidence intervals (CI) using the inverse variance method. Bias risks were assessed according to domains. Trial Sequential Analysis (TSA) was used to control random errors. Eighteen parallel group trials and 43 cross-over trials reported gastrointestinal adverse events. All trials were at high risk of bias. In parallel group trials, methylphenidate decreased appetite (RR 3.66, 95% CI 2.56 to 5.23) and weight (RR 3.89, 95% CI 1.43 to 10.59). In cross-over trials, methylphenidate increased abdominal pain (RR 1.61, 95% CI 1.27 to 2.04). We found no significant differences in the risk according to type, dose, or duration of administration. The required information size was achieved in three out of four outcomes. Conclusion Methylphenidate increases the risks of decreased appetite, weight loss, and abdominal pain in children and adolescents with attention deficit hyperactivity disorder. No differences in the risks of gastrointestinal adverse events according to type, dose, or duration of administration were found. PMID:28617801
Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial.

PubMed

van de Ven, J; Fransen, A F; Schuit, E; van Runnard Heimel, P J; Mol, B W; Oei, S G

2017-09-01

Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial. J van de Ven, AF Fransen, E Schuit, PJ van Runnard Heimel, BW Mol, SG Oei OBJECTIVE: To investigate whether the effect of a one-day simulation-based obstetric team training on patient outcome changes over time. Post-hoc analysis of a multicentre, open, randomised controlled trial that evaluated team training in obstetrics (TOSTI study).We studied women with a singleton pregnancy beyond 24 weeks of gestation in 24 obstetric units. Included obstetric units were randomised to either a one-day, multi-professional simulation-based team training focusing on crew resource management in a medical simulation centre (12 units) or to no team training (12 units). We assessed whether outcomes differed between both groups in each of the first four quarters following the team training and compared the effect of team training over quarters. Primary outcome was a composite outcome of low Apgar score, severe postpartum haemorrhage, trauma due to shoulder dystocia, eclampsia and hypoxic-ischemic encephalopathy. During a one year period after the team training the rate of obstetric complications, both on the composite level and the individual component level, did not differ between any of the quarters. For trauma due to shoulder dystocia team training led to a significant decrease in the first quarter (0.06% versus 0.26%, OR 0.19, 95% CI 0.03 to 0.98) but in the subsequent quarters no significant reductions were observed. Similar results were found for invasive treatment for severe postpartum haemorrhage where a significant increase was only seen in the first quarter (0.4% versus 0.03%, OR 19, 95% CI 2.5-147), and not thereafter. The beneficial effect of a one-day, simulation-based, multiprofessional, obstetric team training seems to decline after three months. If team training is further evaluated or implemented, repetitive training sessions every three months seem therefore recommended. Copyright © 2017 Elsevier B.V. All rights reserved.
Use of the learning conversation improves instructor confidence in life support training: An open randomised controlled cross-over trial comparing teaching feedback mechanisms.

PubMed

Baldwin, Lydia J L; Jones, Christopher M; Hulme, Jonathan; Owen, Andrew

2015-11-01

Feedback is vital for the effective delivery of skills-based education. We sought to compare the sandwich technique and learning conversation structured methods of feedback delivery in competency-based basic life support (BLS) training. Open randomised crossover study undertaken between October 2014 and March 2015 at the University of Birmingham, United Kingdom. Six-hundred and forty healthcare students undertaking a European Resuscitation Council (ERC) BLS course were enrolled, each of whom was randomised to receive teaching using either the sandwich technique or the learning conversation. Fifty-eight instructors were randomised to initially teach using either the learning conversation or sandwich technique, prior to crossing-over and teaching with the alternative technique after a pre-defined time period. Outcome measures included skill acquisition as measured by an end-of-course competency assessment, instructors' perception of teaching with each feedback technique and candidates' perception of the feedback they were provided with. Scores assigned to use of the learning conversation by instructors were significantly more favourable than for the sandwich technique across all but two assessed domains relating to instructor perception of the feedback technique, including all skills-based domains. No difference was seen in either assessment pass rates (80.9% sandwich technique vs. 77.2% learning conversation; OR 1.2, 95% CI 0.85-1.84; p=0.29) or any domain relating to candidates' perception of their teaching technique. This is the first direct comparison of two feedback techniques in clinical medical education using both quantitative and qualitative methodology. The learning conversation is preferred by instructors providing competency-based life support training and is perceived to favour skills acquisition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Effects of almond and pistachio consumption on gut microbiota composition in a randomised cross-over human feeding study

USDA-ARS?s Scientific Manuscript database

Modifying microbiota towards a 'beneficial' composition is a promising approach for improving intestinal as well as overall health. Natural fibers and phytochemicals that reach the proximal colon, such as those present in various nuts, provide substrates for maintaining a healthy and diverse microbi...
Prevention of head louse infestation: a randomised, double-blind, cross-over study of a novel concept product, 1% 1,2-octanediol spray versus placebo.

PubMed

Burgess, Ian F; Brunton, Elizabeth R; French, Rebecca; Burgess, Nazma A; Lee, Peter N

2014-05-30

To determine whether regular use of a spray containing 1,2-octanediol 1%, which has been shown to inhibit survival of head lice, is able to work as a preventive against establishment of new infestations. Randomised, double-blind, cross-over, community study in Cambridgeshire, UK. 63 male and female schoolchildren aged 4-16 years judged to have a high risk of recurrent infestation. Only the youngest member of a household attending school participated. Participants were treated to eliminate lice, randomised between 1% octanediol or placebo sprays for 6 weeks then crossed-over to the other spray for 6 weeks. Parents applied the sprays at least twice weekly or more frequently if the hair was washed. Investigators monitored weekly for infestation and replenished supplies of spray. The primary endpoint was the time taken until the first infestation event occurred. The secondary measure was safety of the product in regular use. Intention-to-treat analysis found a total of 32 confirmed infestations in 20 participants, with 9 of them infested while using both products. In these nine participants the time to first infestation showed a significant advantage to 1% octanediol (p=0.0129). Per-protocol analysis showed only trends because the population included was not large enough to demonstrate significance. There were no serious adverse events and only two adverse events possibly related to treatment, one was a case of transient erythema and another of a rash that resolved after 5 days. Routine use of 1% octanediol spray provided a significant level of protection from infestation. It was concluded that this product is effective if applied regularly and thoroughly. ISRCTN09524995. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
A randomised controlled trial to assess the effectiveness of a nurse-led palliative care intervention for HIV positive patients on antiretroviral therapy: recruitment, refusal, randomisation and missing data.

PubMed

Lowther, Keira; Higginson, Irene J; Simms, Victoria; Gikaara, Nancy; Ahmed, Aabid; Ali, Zipporah; Afuande, Gaudencia; Kariuki, Hellen; Sherr, Lorraine; Jenkins, Rachel; Selman, Lucy; Harding, Richard

2014-09-03

Despite the life threatening nature of an HIV diagnosis and the multidimensional problems experienced by this patient population during antiretroviral therapy, the effectiveness of a palliative care approach for HIV positive patients on ART is as yet unknown. A randomised controlled trial (RCT) was conducted in a sample of 120 HIV positive patients on ART in an urban clinic in Mombasa, Kenya. The intervention was a minimum of seven sessions of multidimensional, person-centred care, given by HIV nurses trained in the palliative care approach over a period of 5 months. Rates of recruitment and refusal, the effectiveness of the randomisation procedure, trial follow-up and attrition and extent of missing data are reported.120 patients (60 randomised to control arm, 60 randomised to intervention arm) were recruited over 5.5 months, with a refusal rate of 55.7%. During the study period, three participants died from cancer, three withdrew (two moved away and one withdrew due to time constraints). All of these patients were in the intervention arm: details are reported. There were five additional missing monthly interviews in both the control and intervention study arm, bringing the total of missing data to 26 data points (4.3%). The quality and implications of these data are discussed extensively and openly, including the effect of full and ethical consent procedures, respondent burden, HIV stigma, accurate randomisation, patient safety and the impact of the intervention. Data on recruitment randomisation, attrition and missing data in clinical trials should be routinely reported, in conjunction with the now established practice of publishing study protocols to enhance research integrity, transparency and quality. Transparency is especially important in cross cultural settings, in which the sources of funding and trial design are often not based in the country of data collection. Findings reported can be used to inform future RCTs in this area. Clinicaltrials.gov NCT01608802.
Simulation in undergraduate paediatrics: a cluster-randomised trial.

PubMed

Morrissey, Benita; Jacob, Hannah; Harnik, Erika; Mackay, Kate; Moreiras, John

2016-10-01

Medical students lack confidence in recognising, assessing and managing unwell patients, particularly children. Our aim was to evaluate the impact of a 1-day novel paediatric simulation course on medical students' ability to recognise and assess sick children, and to evaluate medical students' views on the use of simulation in child health teaching. We conducted a cluster-randomised trial with a mixed-methods design. Students were cluster randomised into the intervention (simulation) group or control group (standard paediatric attachment). Students in the intervention group attended a 1-day simulation course during the last week of their attachment. The primary outcome measure was students' self-reported ability and confidence in recognising, assessing and managing sick children. There were 61 students in the study: 32 in the intervention group and 29 in the control group. Self-assessed confidence in recognising, assessing and managing a sick child was higher after the simulation course, compared with controls (p < 0.001). Six key themes were identified, including: increased confidence in emergency situations; the value of learning through participation in 'real-life' realistic scenarios in a safe environment; and an appreciation of the importance of human factors. Students found the simulation useful and wanted it offered to all undergraduates during child health attachments. A 1-day simulation course improves medical students' confidence in assessing and managing unwell children, and is highly valued by students. It could be used to complement undergraduate teaching on the management of sick children. Further studies are needed to evaluate its impact on real-life clinical performance and confidence over time. Students lack confidence in managing unwell patients, particularly children. © 2015 John Wiley & Sons Ltd.
Oral nutritional supplementation in patients undergoing peritoneal dialysis: a randomised, crossover pilot study.

PubMed

Salamon, Karen M; Lambert, Kelly

2018-06-01

Malnutrition is a significant problem in those undergoing peritoneal dialysis (PD). Factors such as gastrointestinal (GI) symptoms and the need for a fluid reduced diet can limit tolerance and thereby the efficacy of oral nutritional supplements to treat malnutrition. To evaluate the acceptability and impact of two different forms of oral nutrition supplementation for 16 weeks on nutritional markers and quality of life of malnourished patients undergoing PD. A randomised, within-subject cross-over study. Patients assessed as malnourished or with serum albumin <35 g/l were recruited. Participants were randomised to receive either 200 ml of a 1.25 kcal/ml nutrition supplement or a high protein nutrition supplement bar, for eight weeks. Each group then crossed over to receive the alternative supplement for eight weeks. Total intervention time was 16 weeks. Serum albumin, serum transthyretin and food intake were evaluated at baseline, at 8 and 16 weeks. Subjective Global Assessment, the presence of GI symptoms and quality of life were evaluated at baseline and 16 weeks. Sixteen weeks of nutritional support was associated with statistically significant improvements in weight and a reduction in the proportion of patients who were malnourished. There was no difference in the impact of bars compared with liquid oral nutrition supplementation. Patients preferred the fluid supplement to the bars. Sixteen weeks of nutritional support improved nutritional status in malnourished patients on PD. © 2017 European Dialysis and Transplant Nurses Association/European Renal Care Association.

The effect of anthocyanin supplementation in modulating platelet function in sedentary population: a randomised, double-blind, placebo-controlled, cross-over trial.

PubMed

Thompson, Kiara; Hosking, Holly; Pederick, Wayne; Singh, Indu; Santhakumar, Abishek B

2017-09-01

The anti-thrombotic properties of anthocyanin (ACN) supplementation was evaluated in this randomised, double-blind, placebo (PBO) controlled, cross-over design, dietary intervention trial in sedentary population. In all, sixteen participants (three males and thirteen females) consumed ACN (320 mg/d) or PBO capsules for 28 d followed by a 2-week wash-out period. Biomarkers of thrombogenesis and platelet activation induced by ADP; platelet aggregation induced by ADP, collagen and arachidonic acid; biochemical, lipid, inflammatory and coagulation profile were evaluated before and after supplementation. ACN supplementation reduced monocyte-platelet aggregate formation by 39 %; inhibited platelet endothelial cell adhesion molecule-1 expression by 14 %; reduced platelet activation-dependant conformational change and degranulation by reducing procaspase activating compound-1 (PAC-1) (↓10 %) and P-selectin expression (↓14 %), respectively; and reduced ADP-induced whole blood platelet aggregation by 29 %. Arachidonic acid and collagen-induced platelet aggregation; biochemical, lipid, inflammatory and coagulation parameters did not change post-ACN supplementation. PBO treatment did not have an effect on the parameters tested. The findings suggest that dietary ACN supplementation has the potential to alleviate biomarkers of thrombogenesis, platelet hyperactivation and hyper-aggregation in sedentary population.
The effect of pre-course e-learning prior to advanced life support training: a randomised controlled trial.

PubMed

Perkins, Gavin D; Fullerton, James N; Davis-Gomez, Nicole; Davies, Robin P; Baldock, Catherine; Stevens, Harry; Bullock, Ian; Lockey, Andrew S

2010-07-01

The role of e-learning in contemporary healthcare education is quickly developing. The aim of this study was to examine the relationship between the use of an e-learning simulation programme (Microsim, Laerdal, UK) prior to attending an Advanced Life Support (ALS) course and the subsequent relationship to candidate performance. An open label, multi-centre randomised controlled study was conducted. The control group received a course manual and pre-course MCQ four weeks prior to the face to face course. The intervention group in addition received the Microsim programme on a CD. The primary outcome was performance during a simulated cardiac arrest at the end of the course. Secondary outcomes were performance during multiple choice exams, resuscitation skills assessments and feedback to Microsim programme. 572 participants were randomised (287 Microsim, 285 control). There were no significant differences in the primary outcome (performance during a standard cardiac arrest simulation) or secondary outcomes. User evaluations were favorable. 79% would recommend it to colleagues. 9% stated Microsim could replace the entire ALS course, 25% parts. Over 70% of participants' perceived that Microsim improved their understanding of the key learning domains of the ALS course. Distributing Microsim to healthcare providers prior to attending an ALS courses did not improve either cognitive or psychomotor skills performance during cardiac arrest simulation testing. The challenge that lies ahead is to identify the optimal way to use e-learning as part of a blended approach to learning for this type of training programme.
A pilot study to assess the utility of a freely downloadable mobile application simulator for undergraduate clinical skills training: a single-blinded, randomised controlled trial.

PubMed

Bartlett, Richard D; Radenkovic, Dina; Mitrasinovic, Stefan; Cole, Andrew; Pavkovic, Iva; Denn, Peyton Cheong Phey; Hussain, Mahrukh; Kogler, Magdalena; Koutsopodioti, Natalia; Uddin, Wasima; Beckley, Ivan; Abubakar, Hana; Gill, Deborah; Smith, Daron

2017-12-11

Medical simulators offer an invaluable educational resource for medical trainees. However, owing to cost and portability restrictions, they have traditionally been limited to simulation centres. With the advent of sophisticated mobile technology, simulators have become cheaper and more accessible. Touch Surgery is one such freely downloadable mobile application simulator (MAS) used by over one million healthcare professionals worldwide. Nevertheless, to date, it has never been formally validated as an adjunct in undergraduate medical education. Medical students in the final 3 years of their programme were recruited and randomised to one of three revision interventions: 1) no formal revision resources, 2) traditional revision resources, or 3) MAS. Students completed pre-test questionnaires and were then assessed on their ability to complete an undisclosed male urinary catheterisation scenario. Following a one-hour quarantined revision period, all students repeated the scenario. Both attempts were scored by allocation-blinded examiners against an objective 46-point mark scheme. A total of 27 medical students were randomised (n = 9 per group). Mean scores improved between baseline and post-revision attempts by 8.7% (p = 0.003), 19.8% (p = 0.0001), and 15.9% (p = 0.001) for no resources, traditional resources, and MAS, respectively. However, when comparing mean score improvements between groups there were no significant differences. Mobile simulators offer an unconventional, yet potentially useful adjunct to enhance undergraduate clinical skills education. Our results indicate that MAS's perform comparably to current gold-standard revision resources; however, they may confer significant advantages in terms of cost-effectiveness and practice flexibility. Not applicable.
EFFECT of daily antiseptic body wash with octenidine on nosocomial primary bacteraemia and nosocomial multidrug-resistant organisms in intensive care units: design of a multicentre, cluster-randomised, double-blind, cross-over study

PubMed Central

Meißner, Anne; Hasenclever, Dirk; Brosteanu, Oana; Chaberny, Iris Freya

2017-01-01

Introduction Nosocomial infections are serious complications that increase morbidity, mortality and costs and could potentially be avoidable. Antiseptic body wash is an approach to reduce dermal micro-organisms as potential pathogens on the skin. Large-scale trials with chlorhexidine as the antiseptic agent suggest a reduction of nosocomial infection rates. Octenidine is a promising alternative agent which could be more effective against Gram-negative organisms. We hypothesise that daily antiseptic body wash with octenidine reduces the risk of intensive care unit (ICU)-acquired primary bacteraemia and ICU-acquired multidrug-resistant organisms (MDRO) in a standard care setting. Methods and analysis EFFECT is a controlled, cluster-randomised, double-blind study. The experimental intervention consists in using octenidine-impregnated wash mitts for the daily routine washing procedure of the patients. This will be compared with using placebo wash mitts. Replacing existing washing methods is the only interference into clinical routine. Participating ICUs are randomised in an AB/BA cross-over design. There are two 15-month periods, each consisting of a 3-month wash-out period followed by a 12-month intervention and observation period. Randomisation determines only the sequence in which octenidine-impregnated or placebo wash mitts are used. ICUs are left unaware of what mitts packages they are using. The two coprimary endpoints are ICU-acquired primary bacteraemia and ICU-acquired MDRO. Endpoints are defined based on individual ward-movement history and microbiological test results taken from the hospital information systems without need for extra documentation. Data on clinical symptoms of infection are not collected. EFFECT aims at recruiting about 45 ICUs with about 225 000 patient-days per year. Ethics and dissemination The study was approved by the ethics committee of the University of Leipzig (number 340/16-ek) in November 2016. Findings will be published in peer-reviewed journals. Trial registration number DRKS-ID: DRKS00011282. PMID:29122787
Prolonged remission from hepatic encephalopathy with rifaximin: results of a placebo crossover analysis

PubMed Central

Bajaj, J S; Barrett, A C; Bortey, E; Paterson, C; Forbes, W P

2015-01-01

Background Rifaximin therapy reduced risk of hepatic encephalopathy (HE) recurrence and HE-related hospitalisations during a 6-month, randomised, placebo-controlled trial (RCT) and a 24-month open-label maintenance (OLM) study. However, the impact of crossover from placebo to rifaximin therapy is unclear. Aim To study the impact of crossing over from placebo to rifaximin treatment on breakthrough HE and hospitalisation rates using a within-subjects design. Methods Adults with cirrhosis and history of overt HE episodes, currently in HE remission, received placebo during the RCT and crossed over to rifaximin 550 mg twice daily during the OLM study. Rate of breakthrough overt HE episodes, hospitalisations and incidence and rate of adverse events (AEs) were analysed during RCT and first 6 months of OLM. Results Of 82 patients randomised to placebo in the RCT who crossed over to the OLM study, 39 experienced an HE episode during the RCT compared with 14 during the OLM study (P < 0.0001). Significantly lower rates of HE events were observed with rifaximin treatment compared with placebo treatment (P < 0.0001). Rates of HE-related hospitalisation were numerically lower during rifaximin treatment compared with placebo treatment, although not significant. Rates of most common AEs, serious AEs and infection-related AEs were similar between the two treatments. Conclusions This analysis confirms the repeatability of results from the RCT on safety and efficacy of rifaximin 550 mg twice daily in reducing the risk of hepatic encephalopathy recurrence, and suggests these findings are translatable outside of a rigorous, controlled trial setting. PMID:25339518
Computer-Based Instruction for Improving Student Nurses' General Numeracy: Is It Effective? Two Randomised Trials

ERIC Educational Resources Information Center

Ainsworth, Hannah; Gilchrist, Mollie; Grant, Celia; Hewitt, Catherine; Ford, Sue; Petrie, Moira; Torgerson, Carole J.; Torgerson, David J.

2012-01-01

In response to concern over the numeracy skills deficit displayed by student nurses, an online computer programme, "Authentic World[R]", which aims to simulate a real-life clinical environment and improve the medication dosage calculation skills of users, was developed (Founded in 2004 Authentic World Ltd is a spin out company of…
Establishing the effectiveness, cost-effectiveness and student experience of a Simulation-based education Training program On the Prevention of Falls (STOP-Falls) among hospitalised inpatients: a protocol for a randomised controlled trial

PubMed Central

Williams, Cylie; Kiegaldie, Debra; Kaplonyi, Jessica; Haines, Terry

2016-01-01

Introduction Simulation-based education (SBE) is now commonly used across health professional disciplines to teach a range of skills. The evidence base supporting the effectiveness of this approach for improving patient health outcomes is relatively narrow, focused mainly on the development of procedural skills. However, there are other simulation approaches used to support non-procedure specific skills that are in need of further investigation. This cluster, cross-over randomised controlled trial with a concurrent economic evaluation (cost per fall prevented) trial will evaluate the effectiveness, cost-effectiveness and student experience of health professional students undertaking simulation training for the prevention of falls among hospitalised inpatients. This research will target the students within the established undergraduate student placements of Monash University medicine, nursing and allied health across Peninsula Health acute and subacute inpatient wards. Methods and analysis The intervention will train the students in how to provide the Safe Recovery program, the only single intervention approach demonstrated to reduce falls in hospitals. This will involve redevelopment of the Safe Recovery program into a one-to-many participant SBE program, so that groups of students learn the communication skills and falls prevention knowledge necessary for delivery of the program. The primary outcome of this research will be patient falls across participating inpatient wards, with secondary outcomes including student satisfaction with the SBE and knowledge gain, ward-level practice change and cost of acute/rehabilitation care for each patient measured using clinical costing data. Ethics and dissemination The Human Research Ethics Committees of Peninsula Health (LRR/15/PH/11) and Monash University (CF15/3523-2015001384) have approved this research. The participant information and consent forms provide information on privacy, storage of results and dissemination. Registration of this trial has been completed with the Australian and New Zealand Clinical Trials Registry: ACTRN12615000817549. This study protocol has been prepared according to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist. Trial registration number ACTRN12615000817549; Pre-results. PMID:27256087
Impact of a cognitive rehabilitation intervention on neuropsychiatric symptoms in mild to moderate Alzheimer's disease.

PubMed

Brunelle-Hamann, Laurence; Thivierge, Stéphanie; Simard, Martine

2015-01-01

The main goal of this study was to evaluate the impact of a cognitive rehabilitation programme on 12 behavioural and psychological symptoms of dementia (BPSD) in patients with mild to moderate Alzheimer's disease (AD). This six-month single-blind block-randomised cross-over controlled study was conducted with 15 mild to moderate AD participants and their caregivers. All participants received a four-week home-based cognitive rehabilitation programme to learn/re-learn an instrumental activity of daily living. They were assessed up until three months following the end of the intervention. The Neuropsychiatric Inventory (NPI-12) was employed to evaluate patients' BPSD at seven assessment points during the course of the study. A general linear mixed model analysis performed on the NPI data revealed that aberrant motor behaviours (AMB) increased significantly more in the treatment condition than in the control condition. In addition, both groups registered a significant reduction of delusional symptoms during the second half of the study. Employing a multi-symptom approach to assess participants' BPSD, this cross-over randomised controlled study showed that an individualised cognitive rehabilitation intervention was generally well-tolerated by mild to moderate AD patients. Future cognitive rehabilitation studies conducted with this population should pay attention to AMB symptom changes.
Parental presence on neonatal intensive care unit clinical bedside rounds: randomised trial and focus group discussion

PubMed Central

Boswell, Danette; Broom, Margaret; Smith, Judith; Davis, Deborah

2015-01-01

Background There are limited data to inform the choice between parental presence at clinical bedside rounds (PPCBR) and non-PPCBR in neonatal intensive care units (NICUs). Methods We performed a single-centre, survey-based, crossed-over randomised trial involving parents of all infants who were admitted to NICU and anticipated to stay >11 days. Parents were randomly assigned using a computer-generated stratified block randomisation protocol to start with PPCBR or non-PPCBR and then crossed over to the other arm after a wash-out period. At the conclusion of each arm, parents completed the ‘NICU Parental Stressor Scale’ (a validated tool) and a satisfaction survey. After completion of the trial, we surveyed all healthcare providers who participated at least in one PPCBR rounding episode. We also offered all participating parents and healthcare providers the opportunity to partake in a focus group discussion regarding PPCBR. Results A total of 72 parents were enrolled in this study, with 63 parents (87%) partially or fully completing the trial. Of the parents who completed the trial, 95% agreed that parents should be allowed to attend clinical bedside rounds. A total of 39 healthcare providers’ surveys were returned and 35 (90%) agreed that parents should be allowed to attend rounds. Nine healthcare providers and 8 parents participated in an interview or focus group, augmenting our understanding of the ways in which PPCBR was beneficial. Conclusions Parents and healthcare providers strongly support PPCBR. NICUs should develop policies allowing PPCBR while mitigating the downsides and concerns of parents and healthcare providers such as decreased education opportunity and confidentiality concerns. Trial registration number Australia and New Zealand Clinical Trials Register number, ACTRN12612000506897. PMID:25711125
Oral health-related quality of life in patients with non-metal clasp dentures: a randomised cross-over trial.

PubMed

Fueki, K; Yoshida-Kohno, E; Wakabayashi, N

2017-05-01

We investigated the efficacy of non-metal clasp dentures (NMCDs) with regard to the oral health-related quality of life (OHRQoL) and compare the findings with those for conventional metal clasp-retained dentures (MCDs). This single-centre, randomised controlled, two-phase, open label, cross-over trial included 28 partially dentate individuals. The patients were randomised to receive MCDs followed by NMCDs, or the opposite sequence (n = 14 in each group); each denture was worn for 3 months. OHRQoL was evaluated using the Oral Health Impact Profile-Japanese version (OHIP-J) at entry (T-entry; before treatment with the first denture) and at 3 months after treatment with each denture (T3). An examiner evaluated denture stability, oral appearance and surface roughness before denture delivery (T0) and at T3 and denture hygiene at T3. A total of 24 patients completed the trial. There were no complications related to the dentures, abutment teeth or denture-bearing mucosa during the follow-up periods for both dentures. The mean OHIP summary score was lower for NMCDs than for MCDs, and the difference (9 points) was greater than the minimal important difference (6 points), indicating the difference was clinically relevant. The effect size was medium (0·70). Statistical analyses with linear mixed models found a significant effect of the denture type on the OHIP summary score and scores for the Oro-facial appearance, Oro-facial pain and Psychological impact domains (NMCD < MCD; P < 0·05). The results of our study suggest that NMCDs allow for better OHRQoL compared with MCDs. © 2017 John Wiley & Sons Ltd.
The Importance of Specifying and Studying Causal Mechanisms in School-Based Randomised Controlled Trials: Lessons from Two Studies of Cross-Age Peer Tutoring

ERIC Educational Resources Information Center

Morris, Stephen P.; Edovald, Triin; Lloyd, Cheryl; Kiss, Zsolt

2016-01-01

Based on the experience of evaluating 2 cross-age peer-tutoring interventions, we argue that researchers need to pay greater attention to causal mechanisms within the context of school-based randomised controlled trials. Without studying mechanisms, researchers are less able to explain the underlying causal processes that give rise to results from…
Prolonged remission from hepatic encephalopathy with rifaximin: results of a placebo crossover analysis.

PubMed

Bajaj, J S; Barrett, A C; Bortey, E; Paterson, C; Forbes, W P

2015-01-01

Rifaximin therapy reduced risk of hepatic encephalopathy (HE) recurrence and HE-related hospitalisations during a 6-month, randomised, placebo-controlled trial (RCT) and a 24-month open-label maintenance (OLM) study. However, the impact of crossover from placebo to rifaximin therapy is unclear. To study the impact of crossing over from placebo to rifaximin treatment on breakthrough HE and hospitalisation rates using a within-subjects design. Adults with cirrhosis and history of overt HE episodes, currently in HE remission, received placebo during the RCT and crossed over to rifaximin 550 mg twice daily during the OLM study. Rate of breakthrough overt HE episodes, hospitalisations and incidence and rate of adverse events (AEs) were analysed during RCT and first 6 months of OLM. Of 82 patients randomised to placebo in the RCT who crossed over to the OLM study, 39 experienced an HE episode during the RCT compared with 14 during the OLM study (P < 0.0001). Significantly lower rates of HE events were observed with rifaximin treatment compared with placebo treatment (P < 0.0001). Rates of HE-related hospitalisation were numerically lower during rifaximin treatment compared with placebo treatment, although not significant. Rates of most common AEs, serious AEs and infection-related AEs were similar between the two treatments. This analysis confirms the repeatability of results from the RCT on safety and efficacy of rifaximin 550 mg twice daily in reducing the risk of hepatic encephalopathy recurrence, and suggests these findings are translatable outside of a rigorous, controlled trial setting. © 2014 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.
Study for every other day administration of vonoprazan in maintenance treatment of erosive GERD: study protocol for a multicentre randomised cross-over study.

PubMed

Kato, Mototsugu; Ito, Noriko; Demura, Mamiko; Kubo, Kimitoshi; Mabe, Katsuhiro; Harada, Naohiko

2018-01-01

The first drug selected for treatment of gastro-oesophageal reflux disease (GERD) and prevention of the recurrence is a proton pump inhibitor (PPI), but recently, a potassium-competitive acid blocker (P-CAB) was put on the market in Japan. Its onset of effect is faster than PPI, and it takes more than 2 days to recover acid secretion after the withdrawal period. Therefore, unlike PPI, the usefulness of every other day administration or discontinuous administration is expected. This study is a prospective, multicentre, open-label, two-period randomised cross-over study to compare the efficacy and safety of PPI every other day administration and P-CAB every other day administration in 120 patients who receive erosive GERD maintenance therapy with PPI. Patients will be randomly allocated to receive 4 weeks P-CAB or PPI followed by 4 weeks cross over, where those on P-CAB will receive PPI and vice versa. The primary endpoint is proportion of asymptomatic patients. Secondary endpoints are suppressive effect of GERD symptoms, proportion of asymptomatic patients at each time point, safety and cost-saving effect of P-CAB every other day administration, compliance with every other day administration, and proportion of asymptomatic patients at the first month of study drug administration. This study was approved by the National Hospital Organization Central Review Board for Clinical Trials (5 December 2017). If P-CAB every other day administration is established as one of GERD maintenance therapies, there is merit in both medical cost reduction and the safety to alleviate elevation in serum gastrin. UMIN000034701.
Study for every other day administration of vonoprazan in maintenance treatment of erosive GERD: study protocol for a multicentre randomised cross-over study

PubMed Central

Kato, Mototsugu; Ito, Noriko; Demura, Mamiko; Kubo, Kimitoshi; Mabe, Katsuhiro; Harada, Naohiko

2018-01-01

Introduction The first drug selected for treatment of gastro-oesophageal reflux disease (GERD) and prevention of the recurrence is a proton pump inhibitor (PPI), but recently, a potassium-competitive acid blocker (P-CAB) was put on the market in Japan. Its onset of effect is faster than PPI, and it takes more than 2 days to recover acid secretion after the withdrawal period. Therefore, unlike PPI, the usefulness of every other day administration or discontinuous administration is expected. Methods and analysis This study is a prospective, multicentre, open-label, two-period randomised cross-over study to compare the efficacy and safety of PPI every other day administration and P-CAB every other day administration in 120 patients who receive erosive GERD maintenance therapy with PPI. Patients will be randomly allocated to receive 4 weeks P-CAB or PPI followed by 4 weeks cross over, where those on P-CAB will receive PPI and vice versa. The primary endpoint is proportion of asymptomatic patients. Secondary endpoints are suppressive effect of GERD symptoms, proportion of asymptomatic patients at each time point, safety and cost-saving effect of P-CAB every other day administration, compliance with every other day administration, and proportion of asymptomatic patients at the first month of study drug administration. Ethics and dissemination This study was approved by the National Hospital Organization Central Review Board for Clinical Trials (5 December 2017). Discussion If P-CAB every other day administration is established as one of GERD maintenance therapies, there is merit in both medical cost reduction and the safety to alleviate elevation in serum gastrin. Trial registration number UMIN000034701. PMID:29527318
Impact of palm date consumption on microbiota growth and large intestinal health: a randomised, controlled, cross-over, human intervention study.

PubMed

Eid, Noura; Osmanova, Hristina; Natchez, Cecile; Walton, Gemma; Costabile, Adele; Gibson, Glenn; Rowland, Ian; Spencer, Jeremy P E

2015-10-28

The reported inverse association between the intake of plant-based foods and a reduction in the prevalence of colorectal cancer may be partly mediated by interactions between insoluble fibre and (poly)phenols and the intestinal microbiota. In the present study, we assessed the impact of palm date consumption, rich in both polyphenols and fibre, on the growth of colonic microbiota and markers of colon cancer risk in a randomised, controlled, cross-over human intervention study. A total of twenty-two healthy human volunteers were randomly assigned to either a control group (maltodextrin-dextrose, 37·1 g) or an intervention group (seven dates, approximately 50 g). Each arm was of 21 d duration and was separated by a 14-d washout period in a cross-over manner. Changes in the growth of microbiota were assessed by fluorescence in situ hybridisation analysis, whereas SCFA levels were assessed using HPLC. Further, ammonia concentrations, faecal water genotoxicity and anti-proliferation ability were also assessed using different assays, which included cell work and the Comet assay. Accordingly, dietary intakes, anthropometric measurements and bowel movement assessment were also carried out. Although the consumption of dates did not induce significant changes in the growth of select bacterial groups or SCFA, there were significant increases in bowel movements and stool frequency (P<0·01; n 21) and significant reductions in stool ammonia concentration (P<0·05; n 21) after consumption of dates, relative to baseline. Furthermore, date fruit intake significantly reduced genotoxicity in human faecal water relative to control (P<0·01; n 21). Our data indicate that consumption of date fruit may reduce colon cancer risk without inducing changes in the microbiota.
The potential for improvement of outcomes by personalized insulin treatment of type 1 diabetes as assessed by analysis of single-patient data from a randomized controlled cross-over insulin trial.

PubMed

Pedersen-Bjergaard, Ulrik; Kristensen, Peter L; Beck-Nielsen, Henning; Nørgaard, Kirsten; Perrild, Hans; Christiansen, Jens S; Jensen, Tonny; Parving, Hans-Henrik; Thorsteinsson, Birger; Tarnow, Lise

2017-01-01

The evidence for optimal insulin treatment in type 1 diabetes is mainly based on randomised controlled trials applying a parallel-group design. Such trials yield robust general results but crucial individual treatment effects cannot be extracted. We aimed to assess the potential for further improvement of outcomes by personalized insulin therapy by analyzing data from a cross-over trial at individual level. Post hoc analysis of data from a two-year multicentre, prospective, randomised, open, blinded endpoint (PROBE) trial (the HypoAna trial). In a cross-over design 114 patients with type 1 diabetes and recurrent severe hypoglycemia were treated with basal-bolus therapy based on analog (detemir/aspart) or human (NPH/regular) insulin aiming at maintenance of baseline HbA1c levels. For each patient a superior outcome was defined as fewer events of severe hypoglycemia defined by need for third party treatment assistance or a more than 0.4% (4.4mmol/mol) lower HbA1c. Only one quarter had comparable outcome of the two treatments in terms of rate of severe hypoglycemia or HbA1c. Twice as many patients had superior outcome of analog-based as compared to human insulin-based insulin treatment. The rate of severe hypoglycemia with the superior treatment was lower compared to the rates obtained with analog insulin and with human insulin (0.67, 1.09, and 1.57 episode per patient-year, respectively (p<0.0001)). Personalized insulin treatment of type 1 diabetes based on single-patient evidence may improve outcomes significantly compared to a general treatment approach. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
A randomised cross-over pharmacokinetic bioavailability study of synthetic versus kiwifruit-derived vitamin C.

PubMed

Carr, Anitra C; Bozonet, Stephanie M; Vissers, Margreet C M

2013-11-11

Kiwifruit are a rich source of vitamin C and also contain numerous phytochemicals, such as flavonoids, which may influence the bioavailability of kiwifruit-derived vitamin C. The aim of this study was to compare the relative bioavailability of synthetic versus kiwifruit-derived vitamin C using a randomised cross-over pharmacokinetic study design. Nine non-smoking males (aged 18-35 years) received either a chewable tablet (200 mg vitamin C) or the equivalent dose from gold kiwifruit (Actinidia chinensis var. Sungold). Fasting blood and urine were collected half hourly to hourly over the eight hours following intervention. The ascorbate content of the plasma and urine was determined using HPLC with electrochemical detection. Plasma ascorbate levels increased from 0.5 h after the intervention (P = 0.008). No significant differences in the plasma time-concentration curves were observed between the two interventions (P = 0.645). An estimate of the total increase in plasma ascorbate indicated complete uptake of the ingested vitamin C tablet and kiwifruit-derived vitamin C. There was an increase in urinary ascorbate excretion, relative to urinary creatinine, from two hours post intervention (P < 0.001). There was also a significant difference between the two interventions, with enhanced ascorbate excretion observed in the kiwifruit group (P = 0.016). Urinary excretion was calculated as ~40% and ~50% of the ingested dose from the vitamin C tablet and kiwifruit arms, respectively. Overall, our pharmacokinetic study has shown comparable relative bioavailability of kiwifruit-derived vitamin C and synthetic vitamin C.
The Effect of Beta Adrenergic Blockade on Ratings of Perceived Exertion.

DTIC Science & Technology

1984-01-01

exrcis is uvo Hughson, et al. (47) investigated the effect of beta blockade using a single, 100-mg oral dose of metoprolol or matched placebo on 12...administered either placebo, propranolol (80 mug) or metoprolol (100 mug) in a double- blind, randomised manner. Before the muscle-strength tests were...The non-selective BABA propranolol and the selective agent metoprolol were compared with a placebo in a double blind cross-over design. Measurements
EFFECT of daily antiseptic body wash with octenidine on nosocomial primary bacteraemia and nosocomial multidrug-resistant organisms in intensive care units: design of a multicentre, cluster-randomised, double-blind, cross-over study.

PubMed

Meißner, Anne; Hasenclever, Dirk; Brosteanu, Oana; Chaberny, Iris Freya

2017-11-08

Nosocomial infections are serious complications that increase morbidity, mortality and costs and could potentially be avoidable. Antiseptic body wash is an approach to reduce dermal micro-organisms as potential pathogens on the skin. Large-scale trials with chlorhexidine as the antiseptic agent suggest a reduction of nosocomial infection rates. Octenidine is a promising alternative agent which could be more effective against Gram-negative organisms. We hypothesise that daily antiseptic body wash with octenidine reduces the risk of intensive care unit (ICU)-acquired primary bacteraemia and ICU-acquired multidrug-resistant organisms (MDRO) in a standard care setting. EFFECT is a controlled, cluster-randomised, double-blind study. The experimental intervention consists in using octenidine-impregnated wash mitts for the daily routine washing procedure of the patients. This will be compared with using placebo wash mitts. Replacing existing washing methods is the only interference into clinical routine.Participating ICUs are randomised in an AB/BA cross-over design. There are two 15-month periods, each consisting of a 3-month wash-out period followed by a 12-month intervention and observation period. Randomisation determines only the sequence in which octenidine-impregnated or placebo wash mitts are used. ICUs are left unaware of what mitts packages they are using.The two coprimary endpoints are ICU-acquired primary bacteraemia and ICU-acquired MDRO. Endpoints are defined based on individual ward-movement history and microbiological test results taken from the hospital information systems without need for extra documentation. Data on clinical symptoms of infection are not collected. EFFECT aims at recruiting about 45 ICUs with about 225 000 patient-days per year. The study was approved by the ethics committee of the University of Leipzig (number 340/16-ek) in November 2016. Findings will be published in peer-reviewed journals. DRKS-ID: DRKS00011282. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
A randomised study of leadership interventions for healthcare managers.

PubMed

Lornudd, Caroline; Bergman, David; Sandahl, Christer; von Thiele Schwarz, Ulrica

2016-10-03

Purpose The purpose of this paper was to assess two different leader development interventions by comparing their effects on leadership behaviour and evaluating their combined impact after two years, from the viewpoints of both the participating managers and external raters. Design/methodology/approach The study was a longitudinal randomised controlled trial with a cross-over design. Health care managers ( n = 177) were first randomised to either of two 10-month interventions and a year later were switched to the other intervention. Leadership behaviour was rated at pre-test and 12 and 24 months by participating managers and their superiors, colleagues and subordinates using a 360-degree instrument. Analysis of variance and multilevel regression analysis was performed. Findings No difference in effect on leadership behaviour was found between the two interventions. The evaluation of the combined effect of the interventions on leadership behaviour showed inconsistent (i.e. both increased and decreased) ratings by the various rater sources. Practical implications This study provides some evidence that participation in leadership development programmes can improve managers' leadership behaviours, but the results also highlight the interpretive challenges connected with using a 360-degree instrument to evaluate such development. Originality/value The longitudinal randomised controlled design and the large sample comprising both managers and external raters make this study unusually rigorous in the field of leadership development evaluations.

Rationale and methods of a randomised cross-over cluster trial to assess the effectiveness of MOVI-KIDS on preventing obesity in pre-schoolers.

PubMed

Martínez-Vizcaino, Vicente; Mota, Jorge; Solera-Martínez, Montserrat; Notario-Pacheco, Blanca; Arias-Palencia, Natalia; García-Prieto, Jorge Cañete; González-García, Alberto; Álvarez-Bueno, Celia; Sánchez-López, Mairena

2015-02-22

Childhood obesity has become an alarming worldwide increasing public health problem. The earlier adiposity rebound occurs, the greater the risk of becoming obese during puberty and adolescence. It has been speculated about the potential influence of vigorous physical activity on modifying the age of onset of adiposity rebound. Moreover, studies aimed to evaluate the effectiveness of physical activity interventions programs on reducing adiposity and other cardiovascular risk factors in children younger than 6 years are scarce. This paper describes the rationale and methods of a study aimed to test the effectiveness of a two-years multidimensional pre-school intervention on preventing obesity and improving physical fitness during the adiposity rebound period. Twenty-one schools from the provinces of Cuenca and Ciudad Real, Spain, were randomised to an intervention and a control arm. In the first academic year, children in third grade of pre-school and first grade of primary school in the intervention group received the physical activity intervention (MOVI-KIDS). After an academic year schools were crossed over to the alternative arm. According to the socio-ecological model, the intervention included children, their parents and teachers, and the school environment where MOVI-KIDS was conducted. MOVI-KIDS consisted of: i) three-h/week sessions of recreational non-competitive physical activity in after-school time; ii) educational materials to parents and teachers about physical activity benefits and sedentary lifestyle risks; and iii) modifications in the playground to promote physical activity during recess. Baseline and post-intervention outcomes are going to be measured in both arms three times, at the beginning and at the end of first academic year, and at the end of the second academic year. Primary outcomes included body mass index, waist circumference, triceps skinfold thickness, percentage of both body fat and fat-free mass, and blood pressure. Secondary end points were physical activity, fitness, and carotid intima-media thickness. This paper reports the design of a randomised cross-over cluster trial aimed at assessing the effectiveness of the multidimensional physical activity intervention (MOVI-KIDS) during two years in pre-school children. Clinical trials.gov: NCT01971840 . (Date of registration: Initial Release: 10/07/2013; Record Verification: 23/10/2013).
A double blind, placebo controlled, phase II randomised cross-over trial investigating the use of duloxetine for the treatment of chemotherapy-induced peripheral neuropathy.

PubMed

Battaglini, Eva; Park, Susanna B; Barnes, Elizabeth H; Goldstein, David

2018-04-20

Chemotherapy-induced peripheral neuropathy (CIPN) is a significant side effect of cancer treatment, potentially leading to early cessation of chemotherapy, enduring symptoms and long-lasting disability. Evidence from preclinical and clinical studies suggests that duloxetine, a serotonin-noradrenaline reuptake inhibitor, may be effective in the symptomatic treatment of CIPN. This double blind, placebo controlled, phase II randomised cross-over trial aims to determine whether treatment with duloxetine results in a reduction in chronic neuropathic symptoms experienced as a result of neurotoxic chemotherapy treatment. Participants who have received neurotoxic chemotherapy and experience daily symptoms as a consequence of peripheral neuropathy will be randomly allocated to control or experimental group with a 1:1 allocation, stratified by chemotherapy type. The primary endpoint will be patient-reported CIPN symptoms, as assessed via the FACT/GOG-Ntx. As a secondary objective, the trial will investigate whether duloxetine improves neurophysiological parameters and functional status in patients who have received neurotoxic chemotherapy treatment. This trial will investigate the effectiveness of duloxetine in reducing neuropathic symptoms following chemotherapy treatment, and aims to provide insight into the mechanisms underlying the symptomatic relief that duloxetine may provide. These results will be informative in advancing clinical knowledge regarding the treatment of CIPN. Copyright © 2018 Elsevier Inc. All rights reserved.
Effect of lean red meat from lamb v. lean white meat from chicken on the serum lipid profile: a randomised, cross-over study in women.

PubMed

Mateo-Gallego, Rocio; Perez-Calahorra, Sofia; Cenarro, Ana; Bea, Ana M; Andres, Eva; Horno, Jaime; Ros, Emilio; Civeira, Fernando

2012-05-01

The main dietary guidelines recommend restricting total and saturated fat intake in the management of high blood cholesterol levels for cardiovascular risk. These recommendations are usually oversimplified by considering that all red meats should be limited and replaced by white meats. However, lean red meat can be as low in fat as white meat. We examined the effects of red meat (lean breed lamb) and lean white meat (chicken) intake on the lipid profile of a group of women with stable life conditions (nuns living in convents). An open-label, randomised, cross-over study was carried out in thirty-six nuns who consumed either lamb or chicken three times per week for 5-week periods with their usual diet. Clinical, dietary and biochemical variables were evaluated at baseline and the end of each diet period. A validated FFQ was used to assess nutrient intake and monitor compliance. The results showed neither between-diet differences in lipid responses nor differences from baseline in total cholesterol, LDL-cholesterol or TAG for any diet period. In conclusion, consumption of lean red meat (lamb) or lean white meat (chicken) as part of the usual diet is associated with a similar lipid response. These two foods can be exchanged in a healthy diet to increase palatability.
Impact of non-uniform correlation structure on sample size and power in multiple-period cluster randomised trials.

PubMed

Kasza, J; Hemming, K; Hooper, R; Matthews, Jns; Forbes, A B

2017-01-01

Stepped wedge and cluster randomised crossover trials are examples of cluster randomised designs conducted over multiple time periods that are being used with increasing frequency in health research. Recent systematic reviews of both of these designs indicate that the within-cluster correlation is typically taken account of in the analysis of data using a random intercept mixed model, implying a constant correlation between any two individuals in the same cluster no matter how far apart in time they are measured: within-period and between-period intra-cluster correlations are assumed to be identical. Recently proposed extensions allow the within- and between-period intra-cluster correlations to differ, although these methods require that all between-period intra-cluster correlations are identical, which may not be appropriate in all situations. Motivated by a proposed intensive care cluster randomised trial, we propose an alternative correlation structure for repeated cross-sectional multiple-period cluster randomised trials in which the between-period intra-cluster correlation is allowed to decay depending on the distance between measurements. We present results for the variance of treatment effect estimators for varying amounts of decay, investigating the consequences of the variation in decay on sample size planning for stepped wedge, cluster crossover and multiple-period parallel-arm cluster randomised trials. We also investigate the impact of assuming constant between-period intra-cluster correlations instead of decaying between-period intra-cluster correlations. Our results indicate that in certain design configurations, including the one corresponding to the proposed trial, a correlation decay can have an important impact on variances of treatment effect estimators, and hence on sample size and power. An R Shiny app allows readers to interactively explore the impact of correlation decay.
Simulated presence therapy for dementia: a systematic review protocol.

PubMed

Abraha, Iosief; Rimland, Joseph M; Lozano-Montoya, Isabel; Dell'Aquila, Giuseppina; Vélez-Díaz-Pallarés, Manuel; Trotta, Fabiana M; Cherubini, Antonio

2016-05-11

The majority of patients with dementia develop behavioural and psychological symptoms of dementia (BPSD). Non-pharmacological interventions are an appealing alternative for the treatment of BPSD in patients with dementia. Simulated presence therapy (SPT) is a simple and inexpensive non-pharmacological intervention that can be used to treat BPSD. We propose a Cochrane protocol for the collection and assessment of evidence concerning the efficacy of SPT to treat relevant outcomes in people with dementia. We will search the following electronic databases: the Cochrane Dementia and Cognitive Improvement Group's Specialised Register MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS, CENTRAL and a number of trial registers as well as grey literature sources. We will include randomised and quasi-randomised controlled trials (including cross-over studies) that evaluated SPT in people with dementia. Comparators such as usual care with no additional activity, or any activity that differs in content and approach from SPT, but is additional to usual care, will be considered. The primary outcomes of interest will comprise behavioural and psychological symptoms, as measured by relevant scales, and quality of life. Two review authors working independently and in tandem will be involved in title and abstract screening, full-text screening and data abstraction. Where possible, quantitative data will be pooled, and relative risk and mean difference with 95% CI will be employed for dichotomous and continuous data, respectively. Assessment of risk of bias will be performed using the Cochrane risk-of-bias tool and the Grades of Recommendation, Assessment, Development and Evaluation approach. Ethics approval is not required. The final results of this systematic review will be presented to the Cochrane Library and will also be disseminated at relevant conference presentations. CRD42015029778. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
A Randomised Cross-Over Pharmacokinetic Bioavailability Study of Synthetic versus Kiwifruit-Derived Vitamin C

PubMed Central

Carr, Anitra C.; Bozonet, Stephanie M.; Vissers, Margreet C. M.

2013-01-01

Kiwifruit are a rich source of vitamin C and also contain numerous phytochemicals, such as flavonoids, which may influence the bioavailability of kiwifruit-derived vitamin C. The aim of this study was to compare the relative bioavailability of synthetic versus kiwifruit-derived vitamin C using a randomised cross-over pharmacokinetic study design. Nine non-smoking males (aged 18–35 years) received either a chewable tablet (200 mg vitamin C) or the equivalent dose from gold kiwifruit (Actinidia chinensis var. Sungold). Fasting blood and urine were collected half hourly to hourly over the eight hours following intervention. The ascorbate content of the plasma and urine was determined using HPLC with electrochemical detection. Plasma ascorbate levels increased from 0.5 h after the intervention (P = 0.008). No significant differences in the plasma time-concentration curves were observed between the two interventions (P = 0.645). An estimate of the total increase in plasma ascorbate indicated complete uptake of the ingested vitamin C tablet and kiwifruit-derived vitamin C. There was an increase in urinary ascorbate excretion, relative to urinary creatinine, from two hours post intervention (P < 0.001). There was also a significant difference between the two interventions, with enhanced ascorbate excretion observed in the kiwifruit group (P = 0.016). Urinary excretion was calculated as ~40% and ~50% of the ingested dose from the vitamin C tablet and kiwifruit arms, respectively. Overall, our pharmacokinetic study has shown comparable relative bioavailability of kiwifruit-derived vitamin C and synthetic vitamin C. PMID:24284610
Establishing the effectiveness, cost-effectiveness and student experience of a Simulation-based education Training program On the Prevention of Falls (STOP-Falls) among hospitalised inpatients: a protocol for a randomised controlled trial.

PubMed

Williams, Cylie; Bowles, Kelly-Ann; Kiegaldie, Debra; Maloney, Stephen; Nestel, Debra; Kaplonyi, Jessica; Haines, Terry

2016-06-02

Simulation-based education (SBE) is now commonly used across health professional disciplines to teach a range of skills. The evidence base supporting the effectiveness of this approach for improving patient health outcomes is relatively narrow, focused mainly on the development of procedural skills. However, there are other simulation approaches used to support non-procedure specific skills that are in need of further investigation. This cluster, cross-over randomised controlled trial with a concurrent economic evaluation (cost per fall prevented) trial will evaluate the effectiveness, cost-effectiveness and student experience of health professional students undertaking simulation training for the prevention of falls among hospitalised inpatients. This research will target the students within the established undergraduate student placements of Monash University medicine, nursing and allied health across Peninsula Health acute and subacute inpatient wards. The intervention will train the students in how to provide the Safe Recovery program, the only single intervention approach demonstrated to reduce falls in hospitals. This will involve redevelopment of the Safe Recovery program into a one-to-many participant SBE program, so that groups of students learn the communication skills and falls prevention knowledge necessary for delivery of the program. The primary outcome of this research will be patient falls across participating inpatient wards, with secondary outcomes including student satisfaction with the SBE and knowledge gain, ward-level practice change and cost of acute/rehabilitation care for each patient measured using clinical costing data. The Human Research Ethics Committees of Peninsula Health (LRR/15/PH/11) and Monash University (CF15/3523-2015001384) have approved this research. The participant information and consent forms provide information on privacy, storage of results and dissemination. Registration of this trial has been completed with the Australian and New Zealand Clinical Trials Registry: ACTRN12615000817549. This study protocol has been prepared according to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist. ACTRN12615000817549; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Reducing catheter-associated urinary tract infections in hospitals: study protocol for a multi-site randomised controlled study.

PubMed

Mitchell, Brett G; Fasugba, Oyebola; Gardner, Anne; Koerner, Jane; Collignon, Peter; Cheng, Allen C; Graves, Nicholas; Morey, Peter; Gregory, Victoria

2017-11-28

Despite advances in infection prevention and control, catheter-associated urinary tract infections (CAUTIs) are common and remain problematic. A number of measures can be taken to reduce the risk of CAUTI in hospitals. Appropriate urinary catheter insertion procedures are one such method. Reducing bacterial colonisation around the meatal or urethral area has the potential to reduce CAUTI risk. However, evidence about the best antiseptic solutions for meatal cleaning is mixed, resulting in conflicting recommendations in guidelines internationally. This paper presents the protocol for a study to evaluate the effectiveness (objective 1) and cost-effectiveness (objective 2) of using chlorhexidine in meatal cleaning prior to catheter insertion, in reducing catheter-associated asymptomatic bacteriuria and CAUTI. A stepped wedge randomised controlled trial will be undertaken in three large Australian hospitals over a 32-week period. The intervention in this study is the use of chlorhexidine (0.1%) solution for meatal cleaning prior to catheter insertion. During the first 8 weeks of the study, no hospital will receive the intervention. After 8 weeks, one hospital will cross over to the intervention with the other two participating hospitals crossing over to the intervention at 8-week intervals respectively based on randomisation. All sites complete the trial at the same time in 2018. The primary outcomes for objective 1 (effectiveness) are the number of cases of CAUTI and catheter-associated asymptomatic bacteriuria per 100 catheter days will be analysed separately using Poisson regression. The primary outcome for objective 2 (cost-effectiveness) is the changes in costs relative to health benefits (incremental cost-effectiveness ratio) from adoption of the intervention. Results will be disseminated via peer-reviewed journals and presentations at relevant conferences.A dissemination plan it being developed. Results will be published in the peer review literature, presented at relevant conferences and communicated via professional networks. Ethics approval has been obtained. 12617000373370, approved 13/03/2017. Protocol version 1.1. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Influence of carbohydrate supplementation on skill performance during a soccer match simulation.

PubMed

Russell, Mark; Benton, David; Kingsley, Michael

2012-07-01

This study investigated the influence of carbohydrate supplementation on skill performance throughout exercise that replicates soccer match-play. Experimentation was conducted in a randomised, double-blind and cross-over study design. After familiarization, 15 professional academy soccer players completed a soccer match simulation incorporating passing, dribbling and shooting on two separate occasions. Participants received a 6% carbohydrate-electrolyte solution (CHO) or electrolyte solution (PL). Precision, success rate, ball speed and an overall index (speed-precision-success; SPS) were determined for all skills. Blood samples were taken at rest, immediately before exercise, every 15 min during exercise (first half: 15, 30 and 45 min; second half: 60, 75 and 90 min), and 10 min into the half time (half-time). Carbohydrate supplementation influenced shooting (time×treatment interaction: p<0.05), where CHO attenuated the decline in shot speed and SPS index. Supplementation did not affect passing or dribbling. Blood glucose responses to exercise were influenced by supplementation (time×treatment interaction: p<0.05), where concentrations were higher at 45 min and during half-time in CHO compared with PL. Blood glucose concentrations reduced by 30±1% between half-time and 60 min in CHO. Carbohydrate supplementation attenuated decrements in shooting performance during simulated soccer match-play; however, further research is warranted to optimise carbohydrate supplementation regimes for high-intensity intermittent sports. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
A prospective randomised cross-over study of the effect of insulin analogues and human insulin on the frequency of severe hypoglycaemia in patients with type 1 diabetes and recurrent hypoglycaemia (the HypoAna trial): study rationale and design

PubMed Central

2012-01-01

Background Severe hypoglycaemia still represents a significant problem in insulin-treated diabetes. Most patients do not experience severe hypoglycaemia often. However, 20% of patients with type 1 diabetes experience recurrent severe hypoglycaemia corresponding to at least two episodes per year. The effect of insulin analogues on glycaemic control has been documented in large trials, while their effect on the frequency of severe hypoglycaemia is less clear, especially in patients with recurrent severe hypoglycaemia. The HypoAna Trial is designed to investigate whether short-acting and long-acting insulin analogues in comparison with human insulin are superior in reducing the occurrence of severe hypoglycaemic episodes in patients with recurrent hypoglycaemia. This paper reports the study design of the HypoAna Trial. Methods/design The study is a Danish two-year investigator-initiated, prospective, randomised, open, blinded endpoint (PROBE), multicentre, cross-over trial investigating the effect of insulin analogues versus human insulin on the frequency of severe hypoglycaemia in subjects with type 1 diabetes. Patients are randomised to treatment with basal-bolus therapy with insulin detemir / insulin aspart or human NPH insulin / human regular insulin in random order. The major inclusion criterion is history of two or more episodes of severe hypoglycaemia in the preceding year. Discussion In contrast to almost all other studies in this field the HypoAna Trial includes only patients with major problems with hypoglycaemia. The HypoAna Trial will elucidate whether basal-bolus regimen with short-acting and long-acting insulin analogues in comparison with human insulin are superior in reducing occurrence of severe hypoglycaemic episodes in hypoglycaemia prone patients with type 1 diabetes. http://www.clinicaltrials.gov: NCT00346996. PMID:22727048
Sport stacking in auditory and visual attention of grade 3 learners.

PubMed

Mortimer, J; Krysztofiak, J; Custard, S; McKune, A J

2011-08-01

The effect of sport stacking on auditory and visual attention in 32 Grade 3 children was examined using a randomised, cross-over design. Children were randomly assigned to a sport stacking (n=16) or arts/crafts group (n=16) with these activities performed over 3 wk. (12 30-min. sessions, 4 per week). This was followed by a 3-wk. wash-out period after which there was a cross-over and the 3-wk. intervention repeated, with the sports stacking group performing arts/crafts and the arts/crafts group performing sports stacking. Performance on the Integrated Visual and Auditory Continuous Performance Test, a measure of auditory and visual attention, was assessed before and after each of the 3-wk. interventions for each group. Comparisons indicated that sport stacking resulted in significant improvement in high demand function and fine motor regulation, while it caused a significant reduction in low demand function. Auditory and visual attention adaptations to sport stacking may be specific to the high demand nature of the task.
Effects of breaking up sitting on adolescents' postprandial glucose after consuming meals varying in energy: a cross-over randomised trial.

PubMed

Fletcher, Elly A; Salmon, Jo; McNaughton, Sarah A; Orellana, Liliana; Wadley, Glenn D; Bruce, Clinton; Dempsey, Paddy C; Lacy, Kathleen E; Dunstan, David W

2018-03-01

To explore the impact of uninterrupted sitting versus sitting with resistance-type activity breaks on adolescents' postprandial glucose responses while consuming a diet varying in energy. Cross-over randomised trial. Thirteen healthy participants (16.4±1.3years) completed a four-treatment cross-over trial: (1) uninterrupted sitting+high-energy diet; (2) sitting with breaks+high-energy diet; (3) uninterrupted sitting+standard-energy diet; and (4) sitting with breaks+standard-energy diet. For all four conditions, two identical meals were consumed; at 0h and 3h. A continuous glucose monitoring system (CGM) recorded interstitial glucose concentrations every five minutes. Linear mixed models examined differences in glucose positive incremental area under the curve (iAUC) and total AUC between the sitting and diet conditions for the first meal, second meal and entire trial period. Compared to the uninterrupted sitting conditions, the breaks condition elicited a 36.0mmol/L/h (95%CI 6.6-65.5) and 35.9mmol/L/h (95%CI 6.6-65.5) lower iAUC response after the first and second meal, respectively, but not for the entire trial period or for total AUC. Compared to the standard-energy diet, the high-energy diet elicited a 55.0mmol/L/h (95%CI 25.8-84.2) and 75.7mmol/L/h (95%CI 8.6-142.7) higher iAUC response after the first meal and entire trial, respectively. Similar response to the high-energy diet were observed for total AUC. According to iAUC, interrupting sitting had a significant effect on lowering postprandial glucose for both dietary conditions, however, it was not significant when examining total AUC. Larger studies are needed to confirm these findings. ACTRN12615001145594. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Does peer-assisted learning improve academic performance? A scoping review.

PubMed

Williams, Brett; Reddy, Priya

2016-07-01

Due to the diverse and ever-changing nature of the healthcare industry, teaching pedagogies such as peer-assisted learning (PAL) are being implemented to align with external competency standards. A scoping review was conducted in order to map the breadth of literature available on PAL and its impact on student performance. This review used Arksey and O'Malley's six stage scoping methodology. The databases searched included: Cinahl, Ovid Medline, Proquest and Embase as well as grey literature sites and dissertations. 22 articles were included in this review, 10 of which were mixed methods randomised controlled trials, one retrospective study, four controlled trials, two randomised cross over controlled trial, three prospective randomised controlled trials, one thesis and one comparative research design. Analysis of the included articles identified three major themes outlining student performance. Student teachers themselves showed the most significant improvement in objective outcomes. The predominant healthcare field addressed were medical students with very few studies being completed on other professions. The search indicated an overall positive response to PAL with the measurable outcome of student tutors being of most significance. Further research is required to determine the relevance for the wider healthcare community. Copyright © 2016 Elsevier Ltd. All rights reserved.
Whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults.

PubMed

Costello, Joseph T; Baker, Philip R A; Minett, Geoffrey M; Bieuzen, Francois; Stewart, Ian B; Bleakley, Chris

2015-09-18

Recovery strategies are often used with the intention of preventing or minimising muscle soreness after exercise. Whole-body cryotherapy, which involves a single or repeated exposure(s) to extremely cold dry air (below -100 °C) in a specialised chamber or cabin for two to four minutes per exposure, is currently being advocated as an effective intervention to reduce muscle soreness after exercise. To assess the effects (benefits and harms) of whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the British Nursing Index and the Physiotherapy Evidence Database. We also searched the reference lists of articles, trial registers and conference proceedings, handsearched journals and contacted experts.The searches were run in August 2015. We aimed to include randomised and quasi-randomised trials that compared the use of whole-body cryotherapy (WBC) versus a passive or control intervention (rest, no treatment or placebo treatment) or active interventions including cold or contrast water immersion, active recovery and infrared therapy for preventing or treating muscle soreness after exercise in adults. We also aimed to include randomised trials that compared different durations or dosages of WBC. Our prespecified primary outcomes were muscle soreness, subjective recovery (e.g. tiredness, well-being) and adverse effects. Two review authors independently screened search results, selected studies, assessed risk of bias and extracted and cross-checked data. Where appropriate, we pooled results of comparable trials. The random-effects model was used for pooling where there was substantial heterogeneity. We assessed the quality of the evidence using GRADE. Four laboratory-based randomised controlled trials were included. These reported results for 64 physically active predominantly young adults (mean age 23 years). All but four participants were male. Two trials were parallel group trials (44 participants) and two were cross-over trials (20 participants). The trials were heterogeneous, including the type, temperature, duration and frequency of WBC, and the type of preceding exercise. None of the trials reported active surveillance of predefined adverse events. All four trials had design features that carried a high risk of bias, potentially limiting the reliability of their findings. The evidence for all outcomes was classified as 'very low' quality based on the GRADE criteria.Two comparisons were tested: WBC versus control (rest or no WBC), tested in four studies; and WBC versus far-infrared therapy, also tested in one study. No studies compared WBC with other active interventions, such as cold water immersion, or different types and applications of WBC.All four trials compared WBC with rest or no WBC. There was very low quality evidence for lower self-reported muscle soreness (pain at rest) scores after WBC at 1 hour (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -1.42 to -0.12; 20 participants, 2 cross-over trials); 24 hours (SMD -0.57, 95% CI -1.48 to 0.33) and 48 hours (SMD -0.58, 95% CI -1.37 to 0.21), both with 38 participants, 2 cross-over studies, 1 parallel group study; and 72 hours (SMD -0.65, 95% CI -2.54 to 1.24; 29 participants, 1 cross-over study, 1 parallel group study). Of note is that the 95% CIs also included either no between-group differences or a benefit in favour of the control group. One small cross-over trial (9 participants) found no difference in tiredness but better well-being after WBC at 24 hours post exercise. There was no report of adverse events.One small cross-over trial involving nine well-trained runners provided very low quality evidence of lower levels of muscle soreness after WBC, when compared with infrared therapy, at 1 hour follow-up, but not at 24 or 48 hours. The same trial found no difference in well-being but less tiredness after WBC at 24 hours post exercise. There was no report of adverse events. There is insufficient evidence to determine whether whole-body cryotherapy (WBC) reduces self-reported muscle soreness, or improves subjective recovery, after exercise compared with passive rest or no WBC in physically active young adult males. There is no evidence on the use of this intervention in females or elite athletes. The lack of evidence on adverse events is important given that the exposure to extreme temperature presents a potential hazard. Further high-quality, well-reported research in this area is required and must provide detailed reporting of adverse events.
The Tulip GT® airway versus the facemask and Guedel airway: a randomised, controlled, cross-over study by Basic Life Support-trained airway providers in anaesthetised patients.

PubMed

Shaikh, A; Robinson, P N; Hasan, M

2016-03-01

We performed a randomised, controlled, cross-over study of lung ventilation by Basic Life Support-trained providers using either the Tulip GT® airway or a facemask with a Guedel airway in 60 anaesthetised patients. Successful ventilation was achieved if the provider produced an end-tidal CO2 > 3.5 kPa and a tidal volume > 250 ml in two of the first three breaths, within 60 sec and within two attempts. Fifty-seven (95%) providers achieved successful ventilation using the Tulip GT compared with 35 (58%) using the facemask (p < 0.0001). Comparing the Tulip GT and facemask, the mean (SD) end-tidal CO2 was 5.0 (0.7) kPa vs 2.5 (1.5) kPa, tidal volume was 494 (175) ml vs 286 (186) ml and peak inspiratory pressure was 18.3 (3.4) cmH2 O vs 13.6 (7) cmH2 O respectively (all p < 0.0001). Forty-seven (78%) users favoured the Tulip GT airway. These results are similar to a previous manikin study using the same protocol, suggesting a close correlation between human and manikin studies for this airway device. We conclude that the Tulip GT should be considered as an adjunct to airway management both within and outside hospitals when ventilation is being undertaken by Basic Life Support-trained airway providers. © 2015 The Association of Anaesthetists of Great Britain and Ireland.
Indacaterol and glycopyrronium versus indacaterol on body plethysmography measurements in COPD-a randomised controlled study.

PubMed

Salomon, Joerg; Stolz, Daiana; Domenighetti, Guido; Frey, Jean-Georges; Turk, Alexander J; Azzola, Andrea; Sigrist, Thomas; Fitting, Jean-William; Schmidt, Ulrich; Geiser, Thomas; Wild, Corinne; Kostikas, Konstantinos; Clemens, Andreas; Brutsche, Martin

2017-01-11

Dual bronchodilator therapy is recommended for symptomatic patients with chronic obstructive pulmonary disease (COPD). There are limited data on effects of a combination of two long-acting bronchodilators on lung function including body plethysmography. This multicentre, randomised, double-blind, single-dose, cross-over, placebo-controlled study evaluated efficacy and safety of the free combination of indacaterol maleate (IND) and glycopyrronium bromide (GLY) versus IND alone on spirometric and body plethysmography parameters, including inspiratory capacity (IC), forced expiratory volume in 1 s (FEV 1 ), forced vital capacity (FVC), total lung capacity (TLC) and airway resistance (Raw) in moderate-to-severe COPD patients. Seventy-eight patients with FEV 1 % pred. (mean ± SD) 56 ± 13% were randomised. The combination of IND + GLY versus IND presented a numerically higher peak-IC (Δ = 0.076 L, 95% confidence interval [CI]: -0.010 - 0.161 L; p = 0.083), with a statistically significant difference in mean IC over 4 h (Δ = 0.054 L, 95%CI 0.022 - 0.086 L; p = 0.001). FEV 1 , FVC and Raw, but not TLC, were consistently significantly improved by IND + GLY compared to IND alone. Safety profiles of both treatments were comparable. The free combination of IND + GLY improved lung function parameters as evaluated by spirometry and body plethysmography, with a similar safety profile compared to IND alone. NCT01699685.
Push versus gravity for intermittent bolus gavage tube feeding of premature and low birth weight infants.

PubMed

Dawson, Jennifer A; Summan, Ravinder; Badawi, Nadia; Foster, Jann P

2012-11-14

Many small, sick and premature infants are unable to coordinate sucking, swallowing and breathing, and therefore, require gavage feeding. In gavage feeding, milk feeds are delivered through a tube passed via the nose or mouth into the stomach. Intermittent bolus milk feeds may be administered using a syringe to gently push milk into the infant's stomach (push feed). Alternatively, milk can be poured into a syringe attached to the tube and allowed to drip in by gravity (gravity feed). To determine whether the use of push compared with gravity gavage feeding results in a more rapid establishment of full gavage feeds without increasing adverse events in preterm or low birth weight, infants who require intermittent bolus gavage feeding. We searched the following electronic databases to locate randomised controlled or quasi-randomised trials: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2012, Issue 5), MEDLINE (from 1966 to May 2012), EMBASE (from 1980 to May 2012), and CINAHL (from 1982 to May 2012). We used the standard search strategy of the Cochrane Neonatal Review Group. Randomised or quasi-randomised controlled trials comparing push versus gravity intermittent gavage tube feeding in premature or low birth weight, or both, infants. We assessed the methodology of trials regarding blinding of randomisation and outcome measurement. We evaluated treatment effect with a fixed-effect model using risk ratio (RR), relative risk reduction, risk difference (RD) and number needed to treat (NNT) for categorical data; and using mean, standard deviation and weighted mean difference (WMD) for continuous data. We analysed outcomes measured as count data, for example frequency of apnoea, bradycardia and episodes of pulse oximeter oxygen (SpO(2)) desaturation, by comparing rates of events and the rate ratio. We evaluated heterogeneity to help determine the suitability of pooling results. Only one small cross-over trial met the criteria for inclusion in this review and therefore meta-analysis for any of the treatment outcomes was not performed. Symon 1994 reported a trend towards a higher respiratory rate at 10 to 30 minutes following push gavage feeding and no statistical difference in the time taken to give the feeds regardless of the method used. There was one small cross-over study that was included in this review. There is insufficient evidence to recommend either method of gavage feeding. A randomised trial is needed to evaluate the benefits and harms of push versus gravity bolus tube feeding in preterm infants. Infants should be stratified by gestational age at birth (above and below 32 weeks) or birth weight (above and below 1500 grams) and respiratory support (ventilated versus non-ventilated) and the sample size should be of sufficient size to evaluate the primary outcomes outlined in this review (time to establish full tube feeds and feeding intolerance).
Examining the effectiveness of consuming flour made from agronomically biofortified wheat (Zincol-2016/NR-421) for improving Zn status in women in a low-resource setting in Pakistan: study protocol for a randomised, double-blind, controlled cross-over trial (BiZiFED).

PubMed

Lowe, Nicola M; Khan, Muhammad Jaffar; Broadley, Martin R; Zia, Munir H; McArdle, Harry J; Joy, Edward J M; Ohly, Heather; Shahzad, Babar; Ullah, Ubaid; Kabana, Gul; Medhi, Rashid; Afridi, Mukhtiar Zaman

2018-04-17

Dietary zinc (Zn) deficiency is a global problem, particularly in low-income and middle-income countries where access to rich, animal-source foods of Zn is limited due to poverty. In Pakistan, Zn deficiency affects over 40% of the adult female population, resulting in suboptimal immune status and increased likelihood of complications during pregnancy. We are conducting a double-blind, randomised controlled feeding study with cross-over design in a low-resource setting in Pakistan. Households were provided with flour milled from genetically and agronomically biofortified grain (Zincol-2016/NR-421) or control grain (Galaxy-2013). Fifty households were recruited. Each household included a woman aged 16-49 years who is neither pregnant nor breastfeeding, and not currently consuming nutritional supplements. These women were the primary study participants. All households were provided with control flour for an initial 2-week baseline period, followed by an 8-week intervention period where 25 households receive biofortified flour (group A) and 25 households receive control flour (group B). After this 8-week period, groups A and B crossed over, receiving control and biofortified flour respectively for 8 weeks. Tissue (blood, hair and nails) have been collected from the women at five time points: baseline, middle and end of period 1, and middle and end of period 2. Ethical approval was granted from the lead university (reference no. STEMH 697 FR) and the collaborating institution in Pakistan. The final study methods (including any modifications) will be published in peer-reviewed journals, alongside the study outcomes on completion of the data analysis. In addition, findings will be disseminated to the scientific community via conference presentations and abstracts and communicated to the study participants through the village elders at an appropriate community forum. The trial has been registered with the ISRCTN registry, study ID ISRCTN83678069. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
A randomised trial to investigate the effects of acute consumption of a blackcurrant juice drink on markers of vascular reactivity and bioavailability of anthocyanins in human subjects.

PubMed

Jin, Y; Alimbetov, D; George, T; Gordon, M H; Lovegrove, J A

2011-07-01

To study the bioavailability of anthocyanins and the effects of a 20% blackcurrant juice drink on vascular reactivity, plasma antioxidant status and other cardiovascular disease risk markers. The study was a randomised, cross-over, double-blind, placebo-controlled acute meal study. Twenty healthy volunteers (11 females and 9 males) were recruited, and all subjects completed the study. Fasted volunteers consumed a 20% blackcurrant juice drink (250 ml) or a control drink following a low-flavonoid diet for the previous 72 h. Vascular reactivity was assessed at baseline and 120 min after juice consumption by laser Doppler imaging (LDI). Plasma and urine samples were collected periodically over an 8-h period for analysis, with a final urine sample collected at 24 h. The cross-over was performed after a 4-week washout. There were no significant effects of the 20% blackcurrant juice drink on acute measures of vascular reactivity, biomarkers of endothelial function or lipid risk factors. Consumption of the test juice caused increases in plasma vitamin C (P=0.006), and urinary anthocyanins (P<0.001). Delphinidin-3-rutinoside and cyanidin-3-rutinoside were the main anthocyanins excreted in urine with delphinidin-3-glucoside also detected. The yield of anthocyanins in urine was 0.021±0.003% of the dietary intake of delphinidin glycosides and 0.009±0.002% of the dietary intake of cyanidin glycosides. The juice consumption did not have a significant effect on vascular reactivity. Anthocyanins were present at low concentrations in the urine, and microbial metabolites of flavonoids were detected in plasma after juice consumption.
Anthocyanins from fruit juices improve the antioxidant status of healthy young female volunteers without affecting anti-inflammatory parameters: results from the randomised, double-blind, placebo-controlled, cross-over ANTHONIA (ANTHOcyanins in Nutrition Investigation Alliance) study.

PubMed

Kuntz, Sabine; Kunz, Clemens; Herrmann, Johannes; Borsch, Christian H; Abel, Georg; Fröhling, Bettina; Dietrich, Helmut; Rudloff, Silvia

2014-09-28

Anthocyanins (ACN) can exert beneficial health effects not only through their antioxidative potential but also through modulation of inflammatory parameters that play a major role in CVD. A randomised cross-over study was carried out to investigate the effects of ACN-rich beverage ingestion on oxidation- and inflammation-related parameters in thirty healthy female volunteers. The participants consumed 330 ml of beverages (placebo, juice and smoothie with 8·9 (SD 0·3), 983·7 (SD 37) and 840·9 (SD 10) mg/l ACN, respectively) over 14 d. Before and after each intervention, blood and 24 h urine samples were collected. Plasma superoxide dismutase (SOD) and catalase activities increased significantly after ACN-rich beverage ingestion (P<0·001), whereas after placebo juice ingestion no increase could be observed. Plasma glutathione peroxidase and erythrocyte SOD activities were not affected. An increase in Trolox equivalent antioxidant capacity could also be observed after juice (P<0·001) and smoothie (P<0·01) ingestion. The plasma and urinary concentrations of malondialdehyde decreased after ACN-rich beverage ingestion (P<0·001), whereas those of 8-OH-2-deoxyguanosine as well as inflammation-related parameters (IL-2, -6, -8 and -10, C-reactive peptide, soluble cluster of differentiation 40 ligand, TNF-α, monocyte chemoattractant protein-1 and soluble cell adhesion molecules) were not affected. Thus, ingestion of ACN-rich beverages improves antioxidant enzyme activities and plasma antioxidant capacity, thus protecting the body against oxidative stress, a hallmark of ongoing atherosclerosis.

Carotenoids are more bioavailable from papaya than from tomato and carrot in humans: a randomised cross-over study

PubMed Central

Schweiggert, Ralf M.; Kopec, Rachel E.; Villalobos-Gutierrez, Maria G.; Högel, Josef; Quesada, Silvia; Esquivel, Patricia; Schwartz, Steven J.; Carle, Reinhold

2014-01-01

Carrot, tomato and papaya represent important dietary sources of β-carotene and lycopene. The main objective of the present study was to compare the bioavailability of carotenoids from these food sources in healthy human subjects. A total of sixteen participants were recruited for a randomised cross-over study. Test meals containing raw carrots, tomatoes and papayas were adjusted to deliver an equal amount of β-carotene and lycopene. For the evaluation of bioavailability, TAG-rich lipoprotein (TRL) fractions containing newly absorbed carotenoids were analysed over 9.5 h after test meal consumption. The bioavailability of β-carotene from papayas was approximately three times higher than that from carrots and tomatoes, whereas differences in the bioavailability of β-carotene from carrots and tomatoes were insignificant. Retinyl esters appeared in the TRL fractions at a significantly higher concentration after the consumption of the papaya test meal. Similarly, lycopene was approximately 2.6 times more bioavailable from papayas than from tomatoes. Furthermore, the bioavailability of β-cryptoxanthin from papayas was shown to be 2.9 and 2.3 times higher than that of the other papaya carotenoids β-carotene and lycopene, respectively. The morphology of chromoplasts and the physical deposition form of carotenoids were hypothesised to play a major role in the differences observed in the bioavailability of carotenoids from the foods investigated. Particularly, the liquid-crystalline deposition of β-carotene and the storage of lycopene in very small crystalloids in papayas were found to be associated with their high bioavailability. In conclusion, papaya was shown to provide highly bioavailable β-carotene, β-cryptoxanthin and lycopene and may represent a readily available dietary source of provitamin A for reducing the incidence of vitamin A deficiencies in many subtropical and tropical developing countries. PMID:23931131
Consumption of a high-fat meal containing cheese compared with a vegan alternative lowers postprandial C-reactive protein in overweight and obese individuals with metabolic abnormalities: a randomised controlled cross-over study.

PubMed

Demmer, Elieke; Van Loan, Marta D; Rivera, Nancy; Rogers, Tara S; Gertz, Erik R; German, J Bruce; Zivkovic, Angela M; Smilowitz, Jennifer T

2016-01-01

Dietary recommendations suggest decreased consumption of SFA to minimise CVD risk; however, not all foods rich in SFA are equivalent. To evaluate the effects of SFA in a dairy food matrix, as Cheddar cheese, v. SFA from a vegan-alternative test meal on postprandial inflammatory markers, a randomised controlled cross-over trial was conducted in twenty overweight or obese adults with metabolic abnormalities. Individuals consumed two isoenergetic high-fat mixed meals separated by a 1- to 2-week washout period. Serum was collected at baseline, and at 1, 3 and 6 h postprandially and analysed for inflammatory markers (IL-6, IL-8, IL-10, IL-17, IL-18, TNFα, monocyte chemotactic protein-1 (MCP-1)), acute-phase proteins C-reactive protein (CRP) and serum amyloid-A (SAA), cellular adhesion molecules and blood lipids, glucose and insulin. Following both high-fat test meals, postprandial TAG concentrations rose steadily (P < 0·05) without a decrease by 6 h. The incremental AUC (iAUC) for CRP was significantly lower (P < 0·05) in response to the cheese compared with the vegan-alternative test meal. A treatment effect was not observed for any other inflammatory markers; however, for both test meals, multiple markers significantly changed from baseline over the 6 h postprandial period (IL-6, IL-8, IL-18, TNFα, MCP-1, SAA). Saturated fat in the form of a cheese matrix reduced the iAUC for CRP compared with a vegan-alternative test meal during the postprandial 6 h period. The study is registered at clinicaltrials.gov under NCT01803633.
Testing for carryover effects after cessation of treatments: a design approach.

PubMed

Sturdevant, S Gwynn; Lumley, Thomas

2016-08-02

Recently, trials addressing noisy measurements with diagnosis occurring by exceeding thresholds (such as diabetes and hypertension) have been published which attempt to measure carryover - the impact that treatment has on an outcome after cessation. The design of these trials has been criticised and simulations have been conducted which suggest that the parallel-designs used are not adequate to test this hypothesis; two solutions are that either a differing parallel-design or a cross-over design could allow for diagnosis of carryover. We undertook a systematic simulation study to determine the ability of a cross-over or a parallel-group trial design to detect carryover effects on incident hypertension in a population with prehypertension. We simulated blood pressure and focused on varying criteria to diagnose systolic hypertension. Using the difference in cumulative incidence hypertension to analyse parallel-group or cross-over trials resulted in none of the designs having acceptable Type I error rate. Under the null hypothesis of no carryover the difference is well above the nominal 5 % error rate. When a treatment is effective during the intervention period, reliable testing for a carryover effect is difficult. Neither parallel-group nor cross-over designs using the difference in cumulative incidence appear to be a feasible approach. Future trials should ensure their design and analysis is validated by simulation.
Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial.

PubMed

Lockyer, Stacey; Corona, Giulia; Yaqoob, Parveen; Spencer, Jeremy P E; Rowland, Ian

2015-07-14

The leaves of the olive plant (Olea europaea) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10 mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced (P< 0.05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8-24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo, adding to growing evidence that olive phenolics could be beneficial for health.
Effects of whole-grain rye porridge with added inulin and wheat gluten on appetite, gut fermentation and postprandial glucose metabolism: a randomised, cross-over, breakfast study.

PubMed

Lee, Isabella; Shi, Lin; Webb, Dominic-Luc; Hellström, Per M; Risérus, Ulf; Landberg, Rikard

2016-12-01

Whole-grain rye foods reduce appetite, insulin and sometimes glucose responses. Increased gut fermentation and plant protein may mediate the effect. The aims of the present study were to investigate whether the appetite-suppressing effects of whole-grain rye porridge could be enhanced by replacing part of the rye with fermented dietary fibre and plant protein, and to explore the role of gut fermentation on appetite and metabolic responses over 8 h. We conducted a randomised, cross-over study using two rye porridges (40 and 55 g), three 40-g rye porridges with addition of inulin:gluten (9:3; 6:6; 3:9 g) and a refined wheat bread control (55 g), served as part of complete breakfasts. A standardised lunch and an ad libitum dinner were served 4 and 8 h later, respectively. Appetite, breath hydrogen and methane, glucose, insulin and glucagon-like peptide-1 (GLP-1) responses were measured over 8 h. Twenty-one healthy men and women, aged 23-60 years, with BMI of 21-33 kg/m2 participated in this study. Before lunch, the 55-g rye porridges lowered hunger by 20 % and desire to eat by 22 % and increased fullness by 29 % compared with wheat bread (P<0·05). Breath hydrogen increased proportionally to dietary fibre content (P<0·05). Plasma glucose after lunch was 6 % lower after the 55-g rye porridges compared with wheat bread (P<0·05) and correlated to breath hydrogen (P<0·001). No differences were observed in ad libitum food intake, insulin or GLP-1. We conclude that no further increase in satiety was observed when replacing part of the rye with inulin and gluten compared with plain rye porridges.
A randomised open-label cross-over study of inhaler errors, preference and time to achieve correct inhaler use in patients with COPD or asthma: comparison of ELLIPTA with other inhaler devices.

PubMed

van der Palen, Job; Thomas, Mike; Chrystyn, Henry; Sharma, Raj K; van der Valk, Paul Dlpm; Goosens, Martijn; Wilkinson, Tom; Stonham, Carol; Chauhan, Anoop J; Imber, Varsha; Zhu, Chang-Qing; Svedsater, Henrik; Barnes, Neil C

2016-11-24

Errors in the use of different inhalers were investigated in patients naive to the devices under investigation in a multicentre, single-visit, randomised, open-label, cross-over study. Patients with chronic obstructive pulmonary disease (COPD) or asthma were assigned to ELLIPTA vs DISKUS (Accuhaler), metered-dose inhaler (MDI) or Turbuhaler. Patients with COPD were also assigned to ELLIPTA vs Handihaler or Breezhaler. Patients demonstrated inhaler use after reading the patient information leaflet (PIL). A trained investigator assessed critical errors (i.e., those likely to result in the inhalation of significantly reduced, minimal or no medication). If the patient made errors, the investigator demonstrated the correct use of the inhaler, and the patient demonstrated inhaler use again. Fewer COPD patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS, 9/171 (5%) vs 75/171 (44%); MDI, 10/80 (13%) vs 48/80 (60%); Turbuhaler, 8/100 (8%) vs 44/100 (44%); Handihaler, 17/118 (14%) vs 57/118 (48%); Breezhaler, 13/98 (13%) vs 45/98 (46%; all P<0.001). Most patients (57-70%) made no errors using ELLIPTA and did not require investigator instruction. Instruction was required for DISKUS (65%), MDI (85%), Turbuhaler (71%), Handihaler (62%) and Breezhaler (56%). Fewer asthma patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS (3/70 (4%) vs 9/70 (13%), P=0.221); MDI (2/32 (6%) vs 8/32 (25%), P=0.074) and significantly fewer vs Turbuhaler (3/60 (5%) vs 20/60 (33%), P<0.001). More asthma and COPD patients preferred ELLIPTA over the other devices (all P⩽0.002). Significantly, fewer COPD patients using ELLIPTA made critical errors after reading the PIL vs other inhalers. More asthma and COPD patients preferred ELLIPTA over comparator inhalers.
A randomised open-label cross-over study of inhaler errors, preference and time to achieve correct inhaler use in patients with COPD or asthma: comparison of ELLIPTA with other inhaler devices

PubMed Central

van der Palen, Job; Thomas, Mike; Chrystyn, Henry; Sharma, Raj K; van der Valk, Paul DLPM; Goosens, Martijn; Wilkinson, Tom; Stonham, Carol; Chauhan, Anoop J; Imber, Varsha; Zhu, Chang-Qing; Svedsater, Henrik; Barnes, Neil C

2016-01-01

Errors in the use of different inhalers were investigated in patients naive to the devices under investigation in a multicentre, single-visit, randomised, open-label, cross-over study. Patients with chronic obstructive pulmonary disease (COPD) or asthma were assigned to ELLIPTA vs DISKUS (Accuhaler), metered-dose inhaler (MDI) or Turbuhaler. Patients with COPD were also assigned to ELLIPTA vs Handihaler or Breezhaler. Patients demonstrated inhaler use after reading the patient information leaflet (PIL). A trained investigator assessed critical errors (i.e., those likely to result in the inhalation of significantly reduced, minimal or no medication). If the patient made errors, the investigator demonstrated the correct use of the inhaler, and the patient demonstrated inhaler use again. Fewer COPD patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS, 9/171 (5%) vs 75/171 (44%); MDI, 10/80 (13%) vs 48/80 (60%); Turbuhaler, 8/100 (8%) vs 44/100 (44%); Handihaler, 17/118 (14%) vs 57/118 (48%); Breezhaler, 13/98 (13%) vs 45/98 (46%; all P<0.001). Most patients (57–70%) made no errors using ELLIPTA and did not require investigator instruction. Instruction was required for DISKUS (65%), MDI (85%), Turbuhaler (71%), Handihaler (62%) and Breezhaler (56%). Fewer asthma patients made critical errors with ELLIPTA after reading the PIL vs: DISKUS (3/70 (4%) vs 9/70 (13%), P=0.221); MDI (2/32 (6%) vs 8/32 (25%), P=0.074) and significantly fewer vs Turbuhaler (3/60 (5%) vs 20/60 (33%), P<0.001). More asthma and COPD patients preferred ELLIPTA over the other devices (all P⩽0.002). Significantly, fewer COPD patients using ELLIPTA made critical errors after reading the PIL vs other inhalers. More asthma and COPD patients preferred ELLIPTA over comparator inhalers. PMID:27883002
Improved recognition of ineffective chest compressions after a brief Crew Resource Management (CRM) training: a prospective, randomised simulation study.

PubMed

Haffner, Leopold; Mahling, Moritz; Muench, Alexander; Castan, Christoph; Schubert, Paul; Naumann, Aline; Reddersen, Silke; Herrmann-Werner, Anne; Reutershan, Jörg; Riessen, Reimer; Celebi, Nora

2017-03-03

Chest compressions are a core element of cardio-pulmonary resuscitation. Despite periodic training, real-life chest compressions have been reported to be overly shallow and/or fast, very likely affecting patient outcomes. We investigated the effect of a brief Crew Resource Management (CRM) training program on the correction rate of improperly executed chest compressions in a simulated cardiac arrest scenario. Final-year medical students (n = 57) were randomised to receive a 10-min computer-based CRM or a control training on ethics. Acting as team leaders, subjects performed resuscitation in a simulated cardiac arrest scenario before and after the training. Team members performed standardised overly shallow and fast chest compressions. We analysed how often the team leader recognised and corrected improper chest compressions, as well as communication and resuscitation quality. After the CRM training, team leaders corrected improper chest compressions (35.5%) significantly more often compared with those undergoing control training (7.7%, p = 0.03*). Consequently, four students have to be trained (number needed to treat = 3.6) for one improved chest compression scenario. Communication quality assessed by the Leader Behavior Description Questionnaire significantly increased in the intervention group by a mean of 4.5 compared with 2.0 (p = 0.01*) in the control group. A computer-based, 10-min CRM training improved the recognition of ineffective of chest compressions. Furthermore, communication quality increased. As guideline-adherent chest compressions have been linked to improved patient outcomes, our CRM training might represent a brief and affordable approach to increase chest compression quality and potentially improve patient outcomes.
Impact of online education on intern behaviour around joint commission national patient safety goals: a randomised trial.

PubMed

Shaw, Tim J; Pernar, Luise I; Peyre, Sarah E; Helfrick, John F; Vogelgesang, Kaitlin R; Graydon-Baker, Erin; Chretien, Yves; Brown, Elizabeth J; Nicholson, James C; Heit, Jeremy J; Co, John Patrick T; Gandhi, Tejal

2012-10-01

To compare the effectiveness of two types of online learning methodologies for improving the patient-safety behaviours mandated in the Joint Commission National Patient Safety Goals (NPSG). This randomised controlled trial was conducted in 2010 at Massachusetts General Hospital and Brigham and Women's Hospital (BWH) in Boston USA. Incoming interns were randomised to either receive an online Spaced Education (SE) programme consisting of cases and questions that reinforce over time, or a programme consisting of an online slide show followed by a quiz (SQ). The outcome measures included NPSG-knowledge improvement, NPSG-compliant behaviours in a simulation scenario, self-reported confidence in safety and quality, programme acceptability and programme relevance. Both online learning programmes improved knowledge retention. On four out of seven survey items measuring satisfaction and self-reported confidence, the proportion of SE interns responding positively was significantly higher (p<0.05) than the fraction of SQ interns. SE interns demonstrated a mean 4.79 (36.6%) NPSG-compliant behaviours (out of 13 total), while SQ interns completed a mean 4.17 (32.0%) (p=0.09). Among those in surgical fields, SE interns demonstrated a mean 5.67 (43.6%) NPSG-compliant behaviours, while SQ interns completed a mean 2.33 (17.9%) (p=0.015). Focus group data indicates that SE was more contextually relevant than SQ, and significantly more engaging. While both online methodologies improved knowledge surrounding the NPSG, SE was more contextually relevant to trainees and was engaging. SE impacted more significantly on both self-reported confidence and the behaviour of surgical residents in a simulated scenario.
Effect of an interactive cardiopulmonary resuscitation assist device with an automated external defibrillator synchronised with a ventilator on the CPR performance of emergency medical service staff: a randomised simulation study.

PubMed

Nitzschke, Rainer; Doehn, Christoph; Kersten, Jan F; Blanz, Julian; Kalwa, Tobias J; Scotti, Norman A; Kubitz, Jens C

2017-04-04

The present study evaluates whether the quality of advanced cardiac life support (ALS) is improved with an interactive prototype assist device. This device consists of an automated external defibrillator linked to a ventilator and provides synchronised visual and acoustic instructions for guidance through the ALS algorithm and assistance for face-mask ventilations. We compared the cardiopulmonary resuscitation (CPR) quality of emergency medical system (EMS) staff members using the study device or standard equipment in a mannequin simulation study with a prospective, controlled, randomised cross-over study design. Main outcome was the effect of the study device compared to the standard equipment and the effect of the number of prior ALS trainings of the EMS staff on the CPR quality. Data were analysed using analyses of covariance (ANCOVA) and binary logistic regression, accounting for the study design. In 106 simulations of 56 two-person rescuer teams, the mean hands-off time was 24.5% with study equipment and 23.5% with standard equipment (Difference 1.0% (95% CI: -0.4 to 2.5%); p = 0.156). With both types of equipment, the hands-off time decreased with an increasing cumulative number of previous CPR trainings (p = 0.042). The study equipment reduced the mean time until administration of adrenaline (epinephrine) by 23 s (p = 0.003) and that of amiodarone by 17 s (p = 0.016). It also increased the mean number of changes in the person doing chest compressions (0.6 per simulation; p < 0.001) and decreased the mean number of chest compressions (2.8 per minute; p = 0.022) and the mean number of ventilations (1.8 per minute; p < 0.001). The chance of administering amiodarone at the appropriate time was higher, with an odds ratio of 4.15, with the use of the study equipment CPR.com compared to the standard equipment (p = 0.004). With an increasing number of prior CPR trainings, the time intervals in the ALS algorithm until the defibrillations decreased with standard equipment but increased with the study device. EMS staff with limited training in CPR profit from guidance through the ALS algorithm by the study device. However, the study device somehow reduced the ALS quality of well-trained rescuers and thus can only be recommended for ALS provider with limited experience.
Design of simulation-based medical education and advantages and disadvantages of in situ simulation versus off-site simulation.

PubMed

Sørensen, Jette Led; Østergaard, Doris; LeBlanc, Vicki; Ottesen, Bent; Konge, Lars; Dieckmann, Peter; Van der Vleuten, Cees

2017-01-21

Simulation-based medical education (SBME) has traditionally been conducted as off-site simulation in simulation centres. Some hospital departments also provide off-site simulation using in-house training room(s) set up for simulation away from the clinical setting, and these activities are called in-house training. In-house training facilities can be part of hospital departments and resemble to some extent simulation centres but often have less technical equipment. In situ simulation, introduced over the past decade, mainly comprises of team-based activities and occurs in patient care units with healthcare professionals in their own working environment. Thus, this intentional blend of simulation and real working environments means that in situ simulation brings simulation to the real working environment and provides training where people work. In situ simulation can be either announced or unannounced, the latter also known as a drill. This article presents and discusses the design of SBME and the advantage and disadvantage of the different simulation settings, such as training in simulation-centres, in-house simulations in hospital departments, announced or unannounced in situ simulations. Non-randomised studies argue that in situ simulation is more effective for educational purposes than other types of simulation settings. Conversely, the few comparison studies that exist, either randomised or retrospective, show that choice of setting does not seem to influence individual or team learning. However, hospital department-based simulations, such as in-house simulation and in situ simulation, lead to a gain in organisational learning. To our knowledge no studies have compared announced and unannounced in situ simulation. The literature suggests some improved organisational learning from unannounced in situ simulation; however, unannounced in situ simulation was also found to be challenging to plan and conduct, and more stressful among participants. The importance of setting, context and fidelity are discussed. Based on the current limited research we suggest that choice of setting for simulations does not seem to influence individual and team learning. Department-based local simulation, such as simulation in-house and especially in situ simulation, leads to gains in organisational learning. The overall objectives of simulation-based education and factors such as feasibility can help determine choice of simulation setting.
Ultra-low crosstalk, CMOS compatible waveguide crossings for densely integrated photonic interconnection networks.

PubMed

Jones, Adam M; DeRose, Christopher T; Lentine, Anthony L; Trotter, Douglas C; Starbuck, Andrew L; Norwood, Robert A

2013-05-20

We explore the design space for optimizing CMOS compatible waveguide crossings on a silicon photonics platform. This paper presents simulated and experimental excess loss and crosstalk suppression data for vertically integrated silicon nitride over silicon-on-insulator waveguide crossings. Experimental results show crosstalk suppression exceeding -49/-44 dB with simulation results as low as -65/-60 dB for the TE/TM mode in a waveguide crossing with a 410 nm vertical gap.
Active cycle of breathing technique for cystic fibrosis.

PubMed

Mckoy, Naomi A; Wilson, Lisa M; Saldanha, Ian J; Odelola, Olaide A; Robinson, Karen A

2016-07-05

People with cystic fibrosis experience chronic airway infections as a result of mucus build up within the lungs. Repeated infections often cause lung damage and disease. Airway clearance therapies aim to improve mucus clearance, increase sputum production, and improve airway function. The active cycle of breathing technique (also known as ACBT) is an airway clearance method that uses a cycle of techniques to loosen airway secretions including breathing control, thoracic expansion exercises, and the forced expiration technique. This is an update of a previously published review. To compare the clinical effectiveness of the active cycle of breathing technique with other airway clearance therapies in cystic fibrosis. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews.Date of last search: 25 April 2016. Randomised or quasi-randomised controlled clinical studies, including cross-over studies, comparing the active cycle of breathing technique with other airway clearance therapies in cystic fibrosis. Two review authors independently screened each article, abstracted data and assessed the risk of bias of each study. Our search identified 62 studies, of which 19 (440 participants) met the inclusion criteria. Five randomised controlled studies (192 participants) were included in the meta-analysis; three were of cross-over design. The 14 remaining studies were cross-over studies with inadequate reports for complete assessment. The study size ranged from seven to 65 participants. The age of the participants ranged from six to 63 years (mean age 22.33 years). In 13 studies, follow up lasted a single day. However, there were two long-term randomised controlled studies with follow up of one to three years. Most of the studies did not report on key quality items, and therefore, have an unclear risk of bias in terms of random sequence generation, allocation concealment, and outcome assessor blinding. Due to the nature of the intervention, none of the studies blinded participants or the personnel applying the interventions. However, most of the studies reported on all planned outcomes, had adequate follow up, assessed compliance, and used an intention-to-treat analysis.Included studies compared the active cycle of breathing technique with autogenic drainage, airway oscillating devices, high frequency chest compression devices, conventional chest physiotherapy, and positive expiratory pressure. Preference of technique varied: more participants preferred autogenic drainage over the active cycle of breathing technique; more preferred the active cycle of breathing technique over airway oscillating devices; and more were comfortable with the active cycle of breathing technique versus high frequency chest compression. No significant difference was seen in quality of life, sputum weight, exercise tolerance, lung function, or oxygen saturation between the active cycle of breathing technique and autogenic drainage or between the active cycle of breathing technique and airway oscillating devices. There was no significant difference in lung function and the number of pulmonary exacerbations between the active cycle of breathing technique alone or in conjunction with conventional chest physiotherapy. All other outcomes were either not measured or had insufficient data for analysis. There is insufficient evidence to support or reject the use of the active cycle of breathing technique over any other airway clearance therapy. Five studies, with data from eight different comparators, found that the active cycle of breathing technique was comparable with other therapies in outcomes such as participant preference, quality of life, exercise tolerance, lung function, sputum weight, oxygen saturation, and number of pulmonary exacerbations. Longer-term studies are needed to more adequately assess the effects of the active cycle of breathing technique on outcomes important for people with cystic fibrosis such as quality of life and preference.
Changing cluster composition in cluster randomised controlled trials: design and analysis considerations

PubMed Central

2014-01-01

Background There are many methodological challenges in the conduct and analysis of cluster randomised controlled trials, but one that has received little attention is that of post-randomisation changes to cluster composition. To illustrate this, we focus on the issue of cluster merging, considering the impact on the design, analysis and interpretation of trial outcomes. Methods We explored the effects of merging clusters on study power using standard methods of power calculation. We assessed the potential impacts on study findings of both homogeneous cluster merges (involving clusters randomised to the same arm of a trial) and heterogeneous merges (involving clusters randomised to different arms of a trial) by simulation. To determine the impact on bias and precision of treatment effect estimates, we applied standard methods of analysis to different populations under analysis. Results Cluster merging produced a systematic reduction in study power. This effect depended on the number of merges and was most pronounced when variability in cluster size was at its greatest. Simulations demonstrate that the impact on analysis was minimal when cluster merges were homogeneous, with impact on study power being balanced by a change in observed intracluster correlation coefficient (ICC). We found a decrease in study power when cluster merges were heterogeneous, and the estimate of treatment effect was attenuated. Conclusions Examples of cluster merges found in previously published reports of cluster randomised trials were typically homogeneous rather than heterogeneous. Simulations demonstrated that trial findings in such cases would be unbiased. However, simulations also showed that any heterogeneous cluster merges would introduce bias that would be hard to quantify, as well as having negative impacts on the precision of estimates obtained. Further methodological development is warranted to better determine how to analyse such trials appropriately. Interim recommendations include avoidance of cluster merges where possible, discontinuation of clusters following heterogeneous merges, allowance for potential loss of clusters and additional variability in cluster size in the original sample size calculation, and use of appropriate ICC estimates that reflect cluster size. PMID:24884591
Augmented-reality-based skills training for robot-assisted urethrovesical anastomosis: a multi-institutional randomised controlled trial.

PubMed

Chowriappa, Ashirwad; Raza, Syed Johar; Fazili, Anees; Field, Erinn; Malito, Chelsea; Samarasekera, Dinesh; Shi, Yi; Ahmed, Kamran; Wilding, Gregory; Kaouk, Jihad; Eun, Daniel D; Ghazi, Ahmed; Peabody, James O; Kesavadas, Thenkurussi; Mohler, James L; Guru, Khurshid A

2015-02-01

To validate robot-assisted surgery skills acquisition using an augmented reality (AR)-based module for urethrovesical anastomosis (UVA). Participants at three institutions were randomised to a Hands-on Surgical Training (HoST) technology group or a control group. The HoST group was given procedure-based training for UVA within the haptic-enabled AR-based HoST environment. The control group did not receive any training. After completing the task, the control group was offered to cross over to the HoST group (cross-over group). A questionnaire administered after HoST determined the feasibility and acceptability of the technology. Performance of UVA using an inanimate model on the daVinci Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA) was assessed using a UVA evaluation score and a Global Evaluative Assessment of Robotic Skills (GEARS) score. Participants completed the National Aeronautics and Space Administration Task Load Index (NASA TLX) questionnaire for cognitive assessment, as outcome measures. A Wilcoxon rank-sum test was used to compare outcomes among the groups (HoST group vs control group and control group vs cross-over group). A total of 52 individuals participated in the study. UVA evaluation scores showed significant differences in needle driving (3.0 vs 2.3; P = 0.042), needle positioning (3.0 vs 2.4; P = 0.033) and suture placement (3.4 vs 2.6; P = 0.014) in the HoST vs the control group. The HoST group obtained significantly higher scores (14.4 vs 11.9; P 0.012) on the GEARS. The NASA TLX indicated lower temporal demand and effort in the HoST group (5.9 vs 9.3; P = 0.001 and 5.8 vs 11.9; P = 0.035, respectively). In all, 70% of participants found that HoST was similar to the real surgical procedure, and 75% believed that HoST could improve confidence for carrying out the real intervention. Training in UVA in an AR environment improves technical skill acquisition with minimal cognitive demand. © 2014 The Authors. BJU International © 2014 BJU International.
Relation between burden of disease and randomised evidence in sub-Saharan Africa: survey of research.

PubMed

Isaakidis, Petros; Swingler, George H; Pienaar, Elizabeth; Volmink, Jimmy; Ioannidis, John P A

2002-03-23

To evaluate whether the amount of randomised clinical research on various medical conditions is related to the burden of disease and health needs of the local populations in sub-Saharan Africa. Construction and analysis of comprehensive database of randomised controlled trials in sub-Saharan Africa based on Medline, the Cochrane Controlled Trials Register, and several African databases. Sub-Saharan Africa. Number of trials and randomised subjects for each category of disease in the global burden of disease taxonomy; ratios of disability adjusted life years (DALYs) per amount of randomised evidence. 1179 eligible randomised controlled trials were identified. The number of trials published each year increased over time. Almost half of the trials (n=565) had been done in South Africa. There was relatively good correlation between the estimated burden of disease at year 2000 and the number of trials performed (r=0.53, P=0.024) and the number of participants randomised (r=0.68, P=0.002). However,some conditions-for example, injuries (over 20 000 DALYs per patient ever randomised)-were more neglected than others. Despite recent improvements, few clinical trials are done in sub-Saharan Africa. Clinical research in this part of the world should focus more evenly on the major contributors to burden of disease.
Measurement error, time lag, unmeasured confounding: Considerations for longitudinal estimation of the effect of a mediator in randomised clinical trials.

PubMed

Goldsmith, K A; Chalder, T; White, P D; Sharpe, M; Pickles, A

2018-06-01

Clinical trials are expensive and time-consuming and so should also be used to study how treatments work, allowing for the evaluation of theoretical treatment models and refinement and improvement of treatments. These treatment processes can be studied using mediation analysis. Randomised treatment makes some of the assumptions of mediation models plausible, but the mediator-outcome relationship could remain subject to bias. In addition, mediation is assumed to be a temporally ordered longitudinal process, but estimation in most mediation studies to date has been cross-sectional and unable to explore this assumption. This study used longitudinal structural equation modelling of mediator and outcome measurements from the PACE trial of rehabilitative treatments for chronic fatigue syndrome (ISRCTN 54285094) to address these issues. In particular, autoregressive and simplex models were used to study measurement error in the mediator, different time lags in the mediator-outcome relationship, unmeasured confounding of the mediator and outcome, and the assumption of a constant mediator-outcome relationship over time. Results showed that allowing for measurement error and unmeasured confounding were important. Contemporaneous rather than lagged mediator-outcome effects were more consistent with the data, possibly due to the wide spacing of measurements. Assuming a constant mediator-outcome relationship over time increased precision.
Measurement error, time lag, unmeasured confounding: Considerations for longitudinal estimation of the effect of a mediator in randomised clinical trials

PubMed Central

Goldsmith, KA; Chalder, T; White, PD; Sharpe, M; Pickles, A

2016-01-01

Clinical trials are expensive and time-consuming and so should also be used to study how treatments work, allowing for the evaluation of theoretical treatment models and refinement and improvement of treatments. These treatment processes can be studied using mediation analysis. Randomised treatment makes some of the assumptions of mediation models plausible, but the mediator–outcome relationship could remain subject to bias. In addition, mediation is assumed to be a temporally ordered longitudinal process, but estimation in most mediation studies to date has been cross-sectional and unable to explore this assumption. This study used longitudinal structural equation modelling of mediator and outcome measurements from the PACE trial of rehabilitative treatments for chronic fatigue syndrome (ISRCTN 54285094) to address these issues. In particular, autoregressive and simplex models were used to study measurement error in the mediator, different time lags in the mediator–outcome relationship, unmeasured confounding of the mediator and outcome, and the assumption of a constant mediator–outcome relationship over time. Results showed that allowing for measurement error and unmeasured confounding were important. Contemporaneous rather than lagged mediator–outcome effects were more consistent with the data, possibly due to the wide spacing of measurements. Assuming a constant mediator–outcome relationship over time increased precision. PMID:27647810
Magnetization reversal dynamics in Co nanowires with competing magnetic anisotropies

NASA Astrophysics Data System (ADS)

Pal, Semanti; Saha, Susmita; Polley, Debanjan; Barman, Anjan

2011-12-01

We present the magnetization reversal dynamics of Co nanowires with competing magnetic anisotropies. The aspect ratio ( R) of the nanowires is varied between 2.5 and 60, and we observe a cross-over of the directions of the magnetic easy and hard axes at R=6.8. Micromagnetic simulations qualitatively reproduce the observed cross-over and give detailed insight into the reversal mechanisms associated with the cross-over. The reversal mechanism for a field applied along the long axis of the nanowire exhibits a quasi-coherent rotation mode and a corkscrew-like mode, respectively, above and below the cross-over, with the formation of a Bloch domain near the cross-over region. For a field applied along the short axis, the reversal occurs by nucleation and propagation of reversed domains from the two ends of the nanowires for very high values of the aspect ratio down to the cross-over region, but it transforms into quasi-coherent rotation mode for smaller aspect ratios (below the cross-over region).
Effects of lipid emulsion particle size on satiety and energy intake: a randomised cross-over trial.

PubMed

Poppitt, Sally D; Budgett, Stephanie C; MacGibbon, Alastair K; Quek, Siew-Young; Kindleysides, Sophie; Wiessing, Katy R

2018-03-01

Emulsified lipids, with central lipid core surrounded by polar lipid 'protective coat', have been proposed to stimulate the ileal brake, alter appetite, food intake and aid weight control. In addition to lipid composition, emulsion particle size may contribute to efficacy with small droplets providing a larger surface area for gastrointestinal (GI) lipase action and larger droplets prolonging and delaying digestion in the GI tract. Tube feeding studies delivering emulsions directly into the small intestine show clear effects of smaller particle size on appetite and food intake, but evidence from oral feeding studies is sparse. The objective of this study was to determine the effects of lipid emulsion particle size on appetite response and food intake. In a three-arm randomised cross-over, high-phospholipid (PL) dairy lipid emulsions or matched control were consumed at breakfast within a yoghurt smoothie: (i) large-particle size emulsion, LPE (diameter 0.759 µm, 10 g lipid emulsion, 190 g yoghurt), (ii) small-particle size emulsion, SPE (diameter 0.290 µm, 10 g lipid emulsion, 190 g yoghurt), (iii) control non-emulsion, NE (10 g non-emulsion lipid, 190 g yoghurt). Twenty male participants completed the study, where postprandial appetite response was rated using visual analogue scales (VAS) and ad libitum energy intake at a lunch meal measured 3 h later. There was a trend for LPE to suppress hunger (P = 0.08) and enhance fullness (P = 0.24) relative to both SPE and NE but not statistically significant, and no significant effect of either emulsion on food intake at the lunch meal (P > 0.05). Altering particle size of a high-PL emulsion did not enhance satiety or alter eating behaviour in a group of lean men.

Effects of almond and pistachio consumption on gut microbiota composition in a randomised cross-over human feeding study.

PubMed

Ukhanova, Maria; Wang, Xiaoyu; Baer, David J; Novotny, Janet A; Fredborg, Marlene; Mai, Volker

2014-06-28

The modification of microbiota composition to a 'beneficial' one is a promising approach for improving intestinal as well as overall health. Natural fibres and phytochemicals that reach the proximal colon, such as those present in various nuts, provide substrates for the maintenance of healthy and diverse microbiota. The effects of increased consumption of specific nuts, which are rich in fibre as well as various phytonutrients, on human gut microbiota composition have not been investigated to date. The objective of the present study was to determine the effects of almond and pistachio consumption on human gut microbiota composition. We characterised microbiota in faecal samples collected from volunteers in two separate randomised, controlled, cross-over feeding studies (n 18 for the almond feeding study and n 16 for the pistachio feeding study) with 0, 1·5 or 3 servings/d of the respective nuts for 18 d. Gut microbiota composition was analysed using a 16S rRNA-based approach for bacteria and an internal transcribed spacer region sequencing approach for fungi. The 16S rRNA sequence analysis of 528 028 sequence reads, retained after removing low-quality and short-length reads, revealed various operational taxonomic units that appeared to be affected by nut consumption. The effect of pistachio consumption on gut microbiota composition was much stronger than that of almond consumption and included an increase in the number of potentially beneficial butyrate-producing bacteria. Although the numbers of bifidobacteria were not affected by the consumption of either nut, pistachio consumption appeared to decrease the number of lactic acid bacteria (P< 0·05). Increasing the consumption of almonds or pistachios appears to be an effective means of modifying gut microbiota composition.
The effects of flavanone-rich citrus juice on cognitive function and cerebral blood flow: an acute, randomised, placebo-controlled cross-over trial in healthy, young adults.

PubMed

Lamport, Daniel J; Pal, Deepa; Macready, Anna L; Barbosa-Boucas, Sofia; Fletcher, John M; Williams, Claire M; Spencer, Jeremy P E; Butler, Laurie T

2016-12-01

A plausible mechanism underlying flavonoid-associated cognitive effects is increased cerebral blood flow (CBF). However, behavioural and CBF effects following flavanone-rich juice consumption have not been explored. The aim of this study was to investigate whether consumption of flavanone-rich juice is associated with acute cognitive benefits and increased regional CBF in healthy, young adults. An acute, single-blind, randomised, cross-over design was applied with two 500-ml drink conditions - high-flavanone (HF; 70·5 mg) drink and an energy-, and vitamin C- matched, zero-flavanone control. A total of twenty-four healthy young adults aged 18-30 years underwent cognitive testing at baseline and 2-h after drink consumption. A further sixteen, healthy, young adults were recruited for functional MRI assessment, whereby CBF was measured with arterial spin labelling during conscious resting state at baseline as well as 2 and 5 h after drink consumption. The HF drink was associated with significantly increased regional perfusion in the inferior and middle right frontal gyrus at 2 h relative to baseline and the control drink. In addition, the HF drink was associated with significantly improved performance on the Digit Symbol Substitution Test at 2 h relative to baseline and the control drink, but no effects were observed on any other behavioural cognitive tests. These results demonstrate that consumption of flavanone-rich citrus juice in quantities commonly consumed can acutely enhance blood flow to the brain in healthy, young adults. However, further studies are required to establish a direct causal link between increased CBF and enhanced behavioural outcomes following citrus juice ingestion.
Preference, satisfaction and critical errors with Genuair and Breezhaler inhalers in patients with COPD: a randomised, cross-over, multicentre study

PubMed Central

Pascual, Sergi; Feimer, Jan; De Soyza, Anthony; Sauleda Roig, Jaume; Haughney, John; Padullés, Laura; Seoane, Beatriz; Rekeda, Ludmyla; Ribera, Anna; Chrystyn, Henry

2015-01-01

Background: The specific attributes of inhaler devices can influence patient use, satisfaction and treatment compliance, and may ultimately impact on clinical outcomes in patients with chronic obstructive pulmonary disease (COPD). Aims: To assess patient preference, satisfaction and critical inhaler technique errors with Genuair (a multidose inhaler) and Breezhaler (a single-dose inhaler) after 2 weeks of daily use. Methods: Patients with COPD and moderate to severe airflow obstruction were randomised in a cross-over, open-label, multicentre study to consecutive once-daily inhalations of placebo via Genuair and Breezhaler, in addition to current COPD medication. The primary end point was the proportion of patients who preferred Genuair versus Breezhaler after 2 weeks (Patient Satisfaction and Preference Questionnaire). Other end points included overall satisfaction and correct use of the inhalers after 2 weeks, and willingness to continue with each device. Results: Of the 128 patients enrolled, 127 were included in the safety population (male n=91; mean age 67.6 years). Of the 110 of the 123 patients in the intent-to-treat population who indicated an inhaler preference, statistically significantly more patients preferred Genuair than Breezhaler (72.7 vs. 27.3%; P<0.001). Mean overall satisfaction scores were also greater for Genuair than for Breezhaler (5.9 vs. 5.3, respectively; P<0.001). After 2 weeks, there was no statistically significant difference in the number of patients who made ⩾1 critical inhaler technique error with Breezhaler than with Genuair (7.3 vs. 3.3%, respectively). Conclusions: Patient overall preference and satisfaction was significantly higher with Genuair compared with Breezhaler. The proportion of patients making critical inhaler technique errors was low with Genuair and Breezhaler. PMID:25927321
Habitual dietary fibre intake influences gut microbiota response to an inulin-type fructan prebiotic: a randomised, double-blind, placebo-controlled, cross-over, human intervention study.

PubMed

Healey, Genelle; Murphy, Rinki; Butts, Christine; Brough, Louise; Whelan, Kevin; Coad, Jane

2018-01-01

Dysbiotic gut microbiota have been implicated in human disease. Diet-based therapeutic strategies have been used to manipulate the gut microbiota towards a more favourable profile. However, it has been demonstrated that large inter-individual variability exists in gut microbiota response to a dietary intervention. The primary objective of this study was to investigate whether habitually low dietary fibre (LDF) v. high dietary fibre (HDF) intakes influence gut microbiota response to an inulin-type fructan prebiotic. In this randomised, double-blind, placebo-controlled, cross-over study, thirty-four healthy participants were classified as LDF or HDF consumers. Gut microbiota composition (16S rRNA bacterial gene sequencing) and SCFA concentrations were assessed following 3 weeks of daily prebiotic supplementation (Orafti® Synergy 1; 16 g/d) or placebo (Glucidex® 29 Premium; 16 g/d), as well as after 3 weeks of the alternative intervention, following a 3-week washout period. In the LDF group, the prebiotic intervention led to an increase in Bifidobacterium (P=0·001). In the HDF group, the prebiotic intervention led to an increase in Bifidobacterium (P<0·001) and Faecalibacterium (P=0·010) and decreases in Coprococcus (P=0·010), Dorea (P=0·043) and Ruminococcus (Lachnospiraceae family) (P=0·032). This study demonstrates that those with HDF intakes have a greater gut microbiota response and are therefore more likely to benefit from an inulin-type fructan prebiotic than those with LDF intakes. Future studies aiming to modulate the gut microbiota and improve host health, using an inulin-type fructan prebiotic, should take habitual dietary fibre intake into account.
A randomised, double-blind, cross-over trial to evaluate bread, in which gluten has been pre-digested by prolyl endoprotease treatment, in subjects self-reporting benefits of adopting a gluten-free or low-gluten diet.

PubMed

Rees, Dinka; Holtrop, Grietje; Chope, Gemma; Moar, Kim M; Cruickshank, Morven; Hoggard, Nigel

2018-03-01

The aim of the present study was to determine if the enzyme Aspergillus niger prolyl endoprotease (ANPEP), which degrades the immunogenic proline-rich residues in gluten peptides, can be used in the development of new wheat products, suitable for gluten-sensitive (GS) individuals. We have carried out a double-blind, randomised, cross-over trial with two groups of adults; subjects, self-reporting benefits of adopting a gluten-free or low-gluten diet (GS, n 16) and a control non-GS group (n 12). For the trial, volunteers consumed four wheat breads: normal bread, bread treated with 0·8 or 1 % ANPEP and low-protein bread made from biscuit flour. Compared with controls, GS subjects had a favourable cardiovascular lipid profile - lower LDL (4·0 (sem 0·3) v. 2·8 (sem 0·2) mmol/l; P=0·008) and LDL:HDL ratio (3·2 (sem 0·4) v. 1·8 (sem 0·2); P=0·005) and modified haematological profile. The majority of the GS subjects followed a low-gluten lifestyle, which helps to reduce the gastrointestinal (GI) symptoms severity. The low-gluten lifestyle does not have any effect on the quality of life, fatigue or mental state of this population. Consumption of normal wheat bread increased GI symptoms in GS subjects compared with their habitual diet. ANPEP lowered the immunogenic gluten in the treated bread by approximately 40 %. However, when compared with the control bread for inducing GI symptoms, no treatment effects were apparent. ANPEP can be applied in the production of bread with taste, texture and appearance comparable with standard bread.
Effects of chronic consumption of fruit and vegetable puree-based drinks on vasodilation, plasma oxidative stability and antioxidant status.

PubMed

George, T W; Paterson, E; Waroonphan, S; Gordon, M H; Lovegrove, J A

2012-10-01

Fruit and vegetable-rich diets are associated with a reduced cardiovascular disease (CVD) risk. This protective effect may be a result of the phytochemicals present within fruits and vegetables (F&V). However, there can be considerable variation in the content of phytochemical composition of whole F&V depending on growing location, cultivar, season and agricultural practices, etc. Therefore, the present study investigated the effects of consuming fruits and vegetables as puree-based drinks (FVPD) daily on vasodilation, phytochemical bioavailability, antioxidant status and other CVD risk factors. FVPD was chosen to provide a standardised source of F&V material that could be delivered from the same batch to all subjects during each treatment arm of the study. Thirty-nine subjects completed the randomised, controlled, cross-over dietary intervention. Subjects were randomised to consume 200 mL of FVPD (or fruit-flavoured control), daily for 6 weeks with an 8-week washout period between treatments. Dietary intake was measured using two 5-day diet records during each cross-over arm of the study. Blood and urine samples were collected before and after each intervention and vasodilation assessed in 19 subjects using laser Doppler imaging with iontophoresis. FVPD significantly increased dietary vitamin C and carotenoids (P < 0.001), and concomitantly increased plasma α- and β-carotene (P < 0.001) with a near-significant increase in endothelium-dependent vasodilation (P = 0.060). Overall, the findings obtained in the present study showed that FVPD were a useful vehicle to increase fruit and vegetable intake, significantly increasing dietary and plasma phytochemical concentrations with a trend towards increased endothelium-dependent vasodilation. © 2012 The Authors Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.
Immediate effects after stochastic resonance whole-body vibration on physical performance on frail elderly for skilling-up training: a blind cross-over randomised pilot study.

PubMed

Rogan, Slavko; Schmidtbleicher, Dietmar; Radlinger, Lorenz

2014-10-01

This pilot study examined the feasibility outcome recruitment, safety and compliance of the investigation for stochastic resonance whole-body vibration (SR-WBV) training. Another aim was to evaluate the effect size of one SR-WBV intervention session on Short Physical Performance Battery (SPPB), Expanded Timed Get Up-and-Go (ETGUG), isometric maximal voluntary contraction (IMVC) and rate of force development (IRFD) and chair rising (CR). Randomised double-blinded controlled cross-over pilot study. Feasibility outcomes included recruitment, safety and compliance. For secondary outcomes, SPPB, ETGUG, IMVC, IRFD and CR were measured before and 2-min after intervention. Nonparametric Rank-Order Tests of Puri and Sen L Statistics to Ranked Data were proposed. Wilcoxon signed-ranked tests were used to analyse the differences after SR-WBV intervention and sham intervention. Treatment effects between the interventions were compared by a Mann-Whitney U test. Among 24 eligible frail elderly, 12 agreed to participate and 3 drop out. The adherence was 15 of 24 intervention sessions. For secondary outcome, effect sizes (ES) for SR-WBV intervention on SPPB, ETGUG and CR were determined. This pilot study indicate that the training protocol used in this form for frail elderly individuals is feasible but with modification due to the fact that not all defined feasibility outcomes target was met. SR-WBV with 6 Hz, noise level 4 shows benefit improvements on SPPB (ES 0.52), ETGUG (part sit-to-stand movement: ES 0.81; total time: ES 0.85) and CR (ES 0.66). Further research is desired to determine whether a new adapted training protocol is necessary for SR-WBV in the "skilling up" phase in frail elderly individuals.
Sex-specific effects of intranasal oxytocin on thermal pain perception: A randomised, double-blind, placebo-controlled cross-over study.

PubMed

Tracy, Lincoln M; Labuschagne, Izelle; Georgiou-Karistianis, Nellie; Gibson, Stephen J; Giummarra, Melita J

2017-09-01

Chronic neck and shoulder pain (CNSP) is a common musculoskeletal disorder in adults, which is linked to hypersensitivity to noxious stimuli. The hormone oxytocin has been implicated as a potential therapeutic for the management of chronic pain disorders, and has been suggested to have sex-specific effects on the salience of threatening stimuli. This study investigated the influence of intranasal oxytocin on the perception of noxious thermal stimuli. Participants were 24 individuals with CNSP lasting >12months (eight women), and 24 age- and sex-matched healthy, pain-free controls. In a randomised double-blind, placebo-controlled, cross-over study, participants attended two sessions, self-administering intranasal oxytocin (24 IU) in one session, and placebo in another. Participants rated intensity and unpleasantness of thermal heat stimuli at three body sites: the cervical spine, deltoid, and tibialis anterior, on 11-point numerical rating scales. Compared with placebo, intranasal oxytocin increased the perceived intensity of noxious heat stimuli in women with CNSP (Cohen's d=0.71), but not in men with CNSP, or healthy, pain-free controls. Men and women displayed divergent sensitivity across target sites for ratings of pain intensity (partial eta squared=0.12) and pain unpleasantness (partial eta squared=0.24), irrespective of drug condition. Men were more sensitive at the cervical spine and deltoid, whereas women were more sensitive at the tibialis. These findings suggest that oxytocin and endogenous sex hormones may interact to influence the salience of noxious stimuli. The hyperalgesic effects of oxytocin in women suggest that caution should be taken when considering oxytocin in the management of chronic pain. CT-2016-CTN-01313-1; ACTRN12616000532404. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.
Acute effect on ambulatory blood pressure from aerobic exercise: a randomised cross-over study among female cleaners.

PubMed

Lund Rasmussen, Charlotte; Nielsen, Line; Linander Henriksen, Marie; Søgaard, Karen; Krustrup, Peter; Holtermann, Andreas; Korshøj, Mette

2018-02-01

High occupational physical activity (OPA) is shown to increase the risk for elevated blood pressure, cardiovascular diseases and mortality. Conversely, aerobic exercise acutely lowers the blood pressure up to 25 h post exercise. However, it is unknown if this beneficial effect also apply for workers exposed to high levels of OPA. Cleaners constitute a relevant occupational group for this investigation because of a high prevalence of OPA and cardiovascular disease. Accordingly, the objective was to investigate the acute effects on ambulatory blood pressure from a single aerobic exercise session among female cleaners. Twenty-two female cleaners were randomised to a cross-over study with a reference and an aerobic exercise session. Differences in 24-h, work hours, leisure time, and sleep ambulatory blood pressure (ABP) were evaluated using repeated measure 2 × 2 mixed-models. After the aerobic exercise session, the 24-h systolic ambulatory blood pressure was significantly lowered by 2.4 mmHg (p < 0.01) compared to the reference session. The 24-h diastolic ABP was unaltered. During work hours, a lowered systolic ABP of 2.2 mmHg (p = 0.02) and a higher diastolic ABP of 1.5 mmHg (p = 0.03) were found after the aerobic exercise session. During leisure time, the systolic ABP was lowered by 1.7 mmHg (p = 0.04) and the diastolic ABP was unaltered. During sleep, the systolic and diastolic ABP was unaltered. A single aerobic exercise session lowered 24-h systolic ABP of 2.4 mmHg. Thus, an aerobic exercise session seems to be beneficial for lowering the risk of hypertension among cleaners.
Do public access defibrillation (PAD) programmes lead to an increase of patients surviving to discharge from hospital following out of hospital cardiac arrest?--a literature review.

PubMed

Clare, Carl

2006-11-01

To ascertain the evidence for effectiveness of Public Access Defibrillation Programmes using any level of first responder. Structured searches were made of Medline, Cinahl, Embase, and 'All EBM reviews' (CDSR, ACP Journal Club, DARE, CCTR). No limits were set on the searches in terms of date, publication type or language. Limited hand searches were carried out and colleagues approached for potential papers. All 491 results were 'hand searched' for suitability. Potential papers for inclusion were further reviewed by access to abstracts or full text if necessary. The final papers for review were assessed using a recognised checklist. Of a total of 491 results from all databases removal of repeats and papers that did not answer the question led to 22 papers being further reviewed. Of these 19 were excluded and a final three were assessed and reviewed. Of the three papers two were randomised controlled trials (one with cross over design) and one was a non-randomised controlled cross over trial. Two of the papers assessed the use of level one responders and one level two responders. Odds ratios for the trials using level one responders were 1.3 and 1.6. The relative risk (of survival) for the trial using level two responders was 2.0. However all three trials had wide confidence intervals. The use of level one responders probably carries a slight benefit for patients in OOHCA. The use of level two responders may lead to a greater benefit but only for a small section of the population suffering OOHCA. Emphasis must also be placed on the improvement of ambulance response times and bystander CPR rates.
The effect of a cinnamon-, chromium- and magnesium-formulated honey on glycaemic control, weight loss and lipid parameters in type 2 diabetes: an open-label cross-over randomised controlled trial.

PubMed

Whitfield, Patricia; Parry-Strong, Amber; Walsh, Emily; Weatherall, Mark; Krebs, Jeremy D

2016-04-01

This randomised controlled trial assessed the acute and long-term effects of daily supplementation of kanuka honey, formulated with cinnamon, chromium and magnesium on glucose metabolism, weight and lipid parameters in individuals with type 2 diabetes. Twelve individuals with type 2 diabetes received 53.5 g of a formulated honey and a control (non-formulated) kanuka honey in a random order for 40 days, using cross-over design. Fasting glucose, insulin, HbA1c, lipids and anthropometric measures were measured at baseline and end of treatment. A meal tolerance test was performed at baseline to assess acute metabolic response. There was no statistically significant difference in acute glucose metabolism between treatment groups, as measured by the Matsuda index and AUC for glucose and insulin. After the 40-day intervention with honey, fasting glucose did not differ significantly between the two treatments (95 % CI -2.6 to 0.07). There was no statistically significant change in HbA1c or fasting insulin. There was a statistically significant reduction in total cholesterol by -0.29 mmol/L (95 % CI -0.57 to -0.23), LDL cholesterol by -0.29 mmol/L (95 % CI -0.57 to -0.23) and weight by -2.2 kg (95 % CI -4.2 to -0.1). There was a trend towards increased HDL and reduced systolic blood pressure in the intervention treatment. The addition of cinnamon, chromium and magnesium supplementation to kanuka honey was not associated with a significant improvement in glucose metabolism or glycaemic control in individuals with type 2 diabetes. Use of the formulated honey was associated with a reduction in weight and improvements in lipid parameters, and should be investigated further.
Pancreatic enzyme replacement therapy for people with cystic fibrosis.

PubMed

Somaraju, Usha Rani; Solis-Moya, Arturo

2014-10-13

Most people with cystic fibrosis (80% to 90%) need pancreatic enzyme replacement therapy to prevent malnutrition. Enzyme preparations need to be taken whenever food is taken, and the dose needs to be adjusted according to the food consumed. A systematic review on the efficacy and safety of pancreatic enzyme replacement therapy is needed to guide clinical practice, as there is variability between centres with respect to assessment of pancreatic function, time of commencing treatment, dose and choice of supplements. To evaluate the efficacy and safety of pancreatic enzyme replacement therapy in children and adults with cystic fibrosis and to compare the efficacy and safety of different formulations of this therapy and their appropriateness in different age groups. Also, to compare the effects of pancreatic enzyme replacement therapy in cystic fibrosis according to different diagnostic subgroups (e.g. different ages at introduction of therapy and different categories of pancreatic function). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search: 14 August 2014.We also searched an ongoing trials website and the websites of the pharmaceutical companies who manufacture pancreatic enzyme replacements for any additional trials. Most recent search: 12 May 2014. Randomised and quasi-randomised controlled trials in people of any age, with cystic fibrosis and receiving pancreatic enzyme replacement therapy, at any dosage and in any formulation, for a period of not less than four weeks, compared to placebo or other pancreatic enzyme replacement therapy preparations. Two authors independently assessed trials and extracted outcome data. They also assessed the risk of bias of the trials included in the review. One parallel trial and 11 cross-over trials of children and adults with cystic fibrosis were included in the review. The number of participants in each trial varied between 14 and 129 with a total of 426 participants included in the review. All the included trials were for a duration of four weeks. The included trials had mostly an unclear risk of bias from the randomisation process as the details of this were not given; they also mostly had a high risk of attrition bias and reporting bias.We could not combine data from all the trials as they compared different formulations. Findings from individual studies provided insufficient evidence to determine the size and precision of the effects of different formulations. Ten studies reported information on the review's primary outcome (nutritional status); however, we were only able to combine data from two small cross-over studies (n = 41). The estimated gain in body weight was imprecise, 0.32 kg (95% confidence interval -0.03 to 0.67, P = 0.07). Combined data from the same studies gave statistically significant results favouring enteric-coated microspheres over enteric-coated tablets for our secondary outcomes stool frequency, abdominal pain and fecal fat excretion. Data from another single small cross-over study also favoured enteric-coated microspheres over non-enteric-coated tablets with adjuvant cimetidine in terms of stool frequency. There is limited evidence of benefit from enteric-coated microspheres when compared to non-enteric coated pancreatic enzyme preparations up to one month. In the only comparison where we could combine any data, the fact that these were cross-over studies is likely to underestimate the level of inconsistency between the results of the studies due to over-inflation of confidence intervals from the individual studies.There is no evidence on the long-term effectiveness and risks associated with pancreatic enzyme replacement therapy. There is also no evidence on the relative dosages of enzymes needed for people with different levels of severity of pancreatic insufficiency, optimum time to start treatment and variations based on differences in meals and meal sizes. There is a need for a properly designed trial that can answer these questions.
Safety and efficacy of vardenafil versus sertraline in the treatment of premature ejaculation: a randomised, prospective and crossover study.

PubMed

Mathers, M J; Klotz, T; Roth, S; Lümmen, G; Sommer, F

2009-06-01

We investigated safety and efficacy of vardenafil and sertraline in premature ejaculation (PE). Seventy-two men graded their primary PE on a scale of 0-8 (0 = almost never, 8 = almost always). Intravaginal ejaculatory latency time (IELT) was measured. Patients were included if they scored their PE as 4 or greater and their IELTs were less than 1.30 min. After 6 weeks of behavioural psychosexual therapy, 49 patients still had a PE of 4 or greater and an IELT less than 1.30 min and they were randomised: 6 weeks vardenafil (10 mg) or sertraline (50 mg). After a wash-out phase for 1 week, medication was changed in a cross-over design. Initially, all 72 men with PE received behavioural therapy. Twenty-three men were satisfied with treatment and excluded. The remaining 49 men graded their PE as 5.94 +/- 1.6 and IELT was 0.59 min and patients were randomised. Four men discontinued the study. Vardenafil improved PE grading: 2.7 +/- 2.1 (P < 0.01) and IELT increased to 5.01 +/- 3.69 (P < 0.001). PE grading improved 1.92 +/- 1.32, (P < 0.01) and IELT 3.12 +/- 1.89 (P < 0.001) with sertraline. It is concluded that vardenafil and sertraline are useful agents in the pharmacological treatment of PE.
Routine blood cultures in the management of pyelonephritis in pregnancy for improving outcomes.

PubMed

Gomi, Harumi; Goto, Yoshihito; Laopaiboon, Malinee; Usui, Rie; Mori, Rintaro

2015-02-13

Pyelonephritis is a type of urinary tract infection (UTI) that affects the upper urinary tract and kidneys, and is one of the most common conditions for hospitalisation among pregnant women, aside from delivery. Samples of urine and blood are obtained and used for cultures as part of the diagnosis and management of the condition. Acute pyelonephritis requires hospitalisation with intravenous administration of antimicrobial agents. Several studies have questioned the necessity of obtaining blood cultures in addition to urine cultures, citing cost and questioning whether blood testing is superfluous. Pregnant women with bacteraemia require a change in the initial empirical treatment based on the blood culture. However, these cases are not common, and represent approximately 15% to 20% of cases. It is unclear whether blood cultures are essential for the effective management of the condition. To assess the effectiveness of routine blood cultures to improve health outcomes in the management of pyelonephritis in pregnant women. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register without language or date restrictions (31 December 2014). Randomised controlled trials and quasi-randomised trials comparing outcomes among pregnant women with pyelonephritis who received initial management with or without blood cultures. Cluster-randomised trials were eligible for inclusion in this review but none were identified. Clinical trials using a cross-over design were not eligible for inclusion. Two review authors independently assessed one trial report for inclusion. We identified one trial report but this was excluded. No clinical trials met the inclusion criteria for this review. There are no large-scale randomised controlled trials to assess outcomes in the management of pyelonephritis in pregnancy with or without blood cultures. Randomised controlled trials are needed to evaluate the effectiveness of managing pyelonephritis in pregnant women with or without blood cultures, and to assess any adverse outcomes as well as the cost-effectiveness of excluding blood cultures from treatment.
Final results of the TANIA randomised phase III trial of bevacizumab after progression on first-line bevacizumab therapy for HER2-negative locally recurrent/metastatic breast cancer.

PubMed

Vrdoljak, E; Marschner, N; Zielinski, C; Gligorov, J; Cortes, J; Puglisi, F; Aapro, M; Fallowfield, L; Fontana, A; Inbar, M; Kahan, Z; Welt, A; Lévy, C; Brain, E; Pivot, X; Putzu, C; González Martín, A; de Ducla, S; Easton, V; von Minckwitz, G

2016-11-01

The randomised phase III TANIA trial demonstrated that continuing bevacizumab with second-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC) after progression on first-line bevacizumab-containing therapy significantly improved progression-free survival (PFS) compared with chemotherapy alone [hazard ratio (HR) = 0.75, 95% confidence interval (CI) 0.61-0.93]. We report final results from the TANIA trial, including overall survival (OS) and health-related quality of life (HRQoL). Patients with HER2-negative LR/mBC that had progressed on or after first-line bevacizumab plus chemotherapy were randomised to receive standard second-line chemotherapy either alone or with bevacizumab. At second progression, patients initially randomised to bevacizumab continued bevacizumab with their third-line chemotherapy, but those randomised to chemotherapy alone were not allowed to cross over to receive third-line bevacizumab. The primary end point was second-line PFS; secondary end points included third-line PFS, combined second- and third-line PFS, OS, HRQoL and safety. Of the 494 patients randomised, 483 received second-line therapy; 234 patients (47% of the randomised population) continued to third-line study treatment. The median duration of follow-up at the final analysis was 32.1 months in the chemotherapy-alone arm and 30.9 months in the bevacizumab plus chemotherapy arm. There was no statistically significant difference between treatment arms in third-line PFS (HR = 0.79, 95% CI 0.59-1.06), combined second- and third-line PFS (HR = 0.85, 95% CI 0.68-1.05) or OS (HR = 0.96, 95% CI 0.76-1.21). Third-line safety results showed increased incidences of proteinuria and hypertension with bevacizumab, consistent with safety results for the second-line treatment phase. No differences in HRQoL were detected. In this trial, continuing bevacizumab beyond first and second progression of LR/mBC improved second-line PFS, but no improvement in longer term efficacy was observed. The second-line PFS benefit appears to be achieved without detrimentally affecting quality of life. NCT01250379. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Does a single bout of resistance or aerobic exercise after insulin dose reduction modulate glycaemic control in type 2 diabetes? A randomised cross-over trial.

PubMed

Gordon, Brett A; Bird, Stephen R; MacIsaac, Richard J; Benson, Amanda C

2016-10-01

Regular exercise is advocated for individuals with type 2 diabetes, without fully understanding the acute (0-72h post-exercise) glycaemic response. This study assessed post-exercise glycaemic profiles of non-exercising individuals with insulin treated type 2 diabetes, following resistance and aerobic exercise. Randomised cross-over trial. Fourteen individuals with insulin treated type 2 diabetes (9 males, 5 females) aged 58.1±7.1 years (HbA1c: 8.0±0.6%) were allocated to single sessions of resistance (six whole-body exercises, three sets, 8-10 repetitions, 70% 1RM) and aerobic (30min cycling, 60% VO2peak) exercise, 7-days apart, with the day prior to the first exercise day of each intervention being the control condition. Immediately prior to exercise, insulin dosage was halved and breakfast consumed. Continuous glucose monitoring was undertaken to determine area under the curve and glucose excursions. Blood glucose initially increased (0-2h) following both resistance and aerobic exercise (p<0.001), peaking at 12.3±3.4mmolL(-1) and 12.3±3.3mmolL(-1), respectively. Area under the glucose curve was not statistically different over any of the 24h periods (p=0.12), or different in response to resistance (222±41mmolL(-1)24h(-1)) or aerobic (211±40 mmolL(-1)24h(-1)) exercise (p=0.56). Incidence of hyperglycaemia did not differ between exercise modes (p=0.68). Hypoglycaemic events were identified in three and four participants following resistance and aerobic exercise respectively: these did not require treatment. Glycaemic response is not different between exercise modes, although 50% insulin dose reduction prior to exercise impairs the expected improvement. A common clinical recommendation of 50% insulin dose reduction does not appear to cause adverse glycaemic events. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Acid-inhibitory effects of vonoprazan 20 mg compared with esomeprazole 20 mg or rabeprazole 10 mg in healthy adult male subjects--a randomised open-label cross-over study.

PubMed

Sakurai, Y; Mori, Y; Okamoto, H; Nishimura, A; Komura, E; Araki, T; Shiramoto, M

2015-09-01

Proton pump inhibitors (PPIs) are widely used for the treatment of acid-related diseases. Vonoprazan is a member of a new class of acid suppressants; potassium-competitive acid blockers. Vonoprazan may thus be an alternative to PPIs. To evaluate efficacy, rapidity and duration of acid-inhibitory effects of vonoprazan vs. two control PPIs, esomeprazole and rabeprazole, in 20 healthy Japanese adult male volunteers with CYP2C19 extensive metaboliser genotype. In this randomised, open-label, two-period cross-over study, vonoprazan 20 mg and esomeprazole 20 mg (Study V vs. E) or rabeprazole 10 mg (Study V vs. R) were orally administered daily for 7 days. Primary pharmacodynamic endpoint was gastric pH over 24 h measured as percentage of time pH ≥3, ≥4 and ≥5 (pH holding time ratios; HTRs) and mean gastric pH. Acid-inhibitory effect (pH4 HTR) of vonoprazan was significantly greater than that of esomeprazole or rabeprazole on both Days 1 and 7; Day 7 difference in pH4 HTR for vonoprazan vs. esomeprazole was 24.6% [95% confidence interval (CI): 16.2-33.1] and for vonoprazan vs. rabeprazole 28.8% [95% CI: 17.2-40.4]. The Day 1 to Day 7 ratio of 24-h pH4 HTRs was >0.8 for vonoprazan, compared with 0.370 for esomeprazole and 0.393 for rabeprazole. Vonoprazan was generally well tolerated. One vonoprazan subject withdrew due to a rash which resolved after discontinuation. This study demonstrated a more rapid and sustained acid-inhibitory effect of vonoprazan 20 mg vs. esomeprazole 20 mg or rabeprazole 10 mg. Therefore, vonoprazan may be a potentially new treatment for acid-related diseases. © 2015 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.
A causal model for longitudinal randomised trials with time-dependent non-compliance

PubMed Central

Becque, Taeko; White, Ian R; Haggard, Mark

2015-01-01

In the presence of non-compliance, conventional analysis by intention-to-treat provides an unbiased comparison of treatment policies but typically under-estimates treatment efficacy. With all-or-nothing compliance, efficacy may be specified as the complier-average causal effect (CACE), where compliers are those who receive intervention if and only if randomised to it. We extend the CACE approach to model longitudinal data with time-dependent non-compliance, focusing on the situation in which those randomised to control may receive treatment and allowing treatment effects to vary arbitrarily over time. Defining compliance type to be the time of surgical intervention if randomised to control, so that compliers are patients who would not have received treatment at all if they had been randomised to control, we construct a causal model for the multivariate outcome conditional on compliance type and randomised arm. This model is applied to the trial of alternative regimens for glue ear treatment evaluating surgical interventions in childhood ear disease, where outcomes are measured over five time points, and receipt of surgical intervention in the control arm may occur at any time. We fit the models using Markov chain Monte Carlo methods to obtain estimates of the CACE at successive times after receiving the intervention. In this trial, over a half of those randomised to control eventually receive intervention. We find that surgery is more beneficial than control at 6months, with a small but non-significant beneficial effect at 12months. © 2015 The Authors. Statistics in Medicine Published by JohnWiley & Sons Ltd. PMID:25778798
Adjusting for multiple prognostic factors in the analysis of randomised trials

PubMed Central

2013-01-01

Background When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method. Methods We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome. Results Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power. Conclusions It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not generally need to depend on the method of randomisation used. Most methods of analysis work well with large sample sizes, however treating strata as random effects should be the analysis method of choice with binary or time-to-event outcomes and a small sample size. PMID:23898993
Study of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial.

PubMed

Chu, Tanya T W; Benzie, Iris F F; Lam, Christopher W K; Fok, Benny S P; Lee, Kenneth K C; Tomlinson, Brian

2012-04-01

Previous studies have suggested that Lingzhi (Ganoderma lucidum) has antioxidant effects and possibly beneficial effects on blood pressure, plasma lipids and glucose, but these have not been confirmed in subjects with mild hypertension or hyperlipidaemia. The objective of the present study was to assess the cardiovascular, metabolic, antioxidant and immunomodulatory responses to therapy with Lingzhi in patients with borderline elevations of blood pressure and/or cholesterol in a controlled cross-over trial. A total of twenty-six patients received 1·44 g Lingzhi daily or matching placebo for 12 weeks in a randomised, double-blind, cross-over study with placebo-controlled run-in and cross-over periods. Body weight, blood pressure, metabolic parameters, urine catecholamines and cortisol, antioxidant status and lymphocyte subsets were measured after each period. Lingzhi was well tolerated and data from twenty-three evaluable subjects showed no changes in BMI or blood pressure when treated with Lingzhi or placebo. Plasma insulin and homeostasis model assessment-insulin resistance were lower after treatment with Lingzhi than after placebo. TAG decreased and HDL-cholesterol increased with Lingzhi but not with placebo in the first treatment period, but significant carry-over effects prevented complete analysis of these parameters. Urine catecholamines and cortisol, plasma antioxidant status and blood lymphocyte subsets showed no significant differences across treatments. Results indicate that Lingzhi might have mild antidiabetic effects and potentially improve the dyslipidaemia of diabetes, as shown previously in some animal studies. Further studies are desirable in patients with hyperglycaemia.

Botulinum toxin for motor and phonic tics in Tourette's syndrome.

PubMed

Pandey, Sanjay; Srivanitchapoom, Prachaya; Kirubakaran, Richard; Berman, Brian D

2018-01-05

Gilles de la Tourette syndrome, or Tourette's syndrome, is defined as the presence of both motor and vocal (phonic) tics for more than 12 months, that manifest before the age of 18 years, in the absence of secondary causes. Treatment of motor and phonic tics is difficult and challenging. To determine the safety and effectiveness of botulinum toxin in treating motor and phonic tics in people with Tourette's syndrome, and to analyse the effect of botulinum toxin on premonitory urge and sensory tics. We searched the Cochrane Movement Disorders Group Trials Register, CENTRAL, MEDLINE, and two trials registers to 25 October 2017. We reviewed reference lists of relevant articles for additional trials. We considered all randomised, controlled, double-blind studies comparing botulinum toxin to placebo or other medications for the treatment of motor and phonic tics in Tourette's syndrome for this review. We sought both parallel group and cross-over studies of children or adults, at any dose, and for any duration. We followed standard Cochrane methods to select studies, assess risk of bias, extract and analyse data. All authors independently abstracted data onto standardized forms; disagreements were resolved by mutual discussion. Only one randomised placebo-controlled, double-blind cross-over study met our selection criteria. In this study, 20 participants with motor tics were enrolled over a three-year recruitment period; 18 (14 of whom had a diagnosis of Tourette's syndrome) completed the study; in total, 21 focal motor tics were treated. Although we considered most bias domains to be at low risk of bias, the study recruited a small number of participants with relatively mild tics and provided limited data for our key outcomes. The effects of botulinum toxin injections on tic frequency, measured by videotape or rated subjectively, and on premonitory urge, are uncertain (very low-quality evidence). The quality of evidence for adverse events following botulinum toxin was very low. Nine people had muscle weakness following the injection, which could have led to unblinding of treatment group assignment. No data were available to evaluate whether botulinum injections led to immunoresistance to botulinum. We are uncertain about botulinum toxin effects in the treatment of focal motor and phonic tics in select cases, as we assessed the quality of the evidence as very low. Additional randomised controlled studies are needed to demonstrate the benefits and harms of botulinum toxin therapy for the treatment of motor and phonic tics in patients with Tourette's syndrome.
Virtual reality simulation training for health professions trainees in gastrointestinal endoscopy.

PubMed

Walsh, Catharine M; Sherlock, Mary E; Ling, Simon C; Carnahan, Heather

2012-06-13

Traditionally, training in gastrointestinal endoscopy has been based upon an apprenticeship model, with novice endoscopists learning basic skills under the supervision of experienced preceptors in the clinical setting. Over the last two decades, however, the growing awareness of the need for patient safety has brought the issue of simulation-based training to the forefront. While the use of simulation-based training may have important educational and societal advantages, the effectiveness of virtual reality gastrointestinal endoscopy simulators has yet to be clearly demonstrated. To determine whether virtual reality simulation training can supplement and/or replace early conventional endoscopy training (apprenticeship model) in diagnostic oesophagogastroduodenoscopy, colonoscopy and/or sigmoidoscopy for health professions trainees with limited or no prior endoscopic experience. Health professions, educational and computer databases were searched until November 2011 including The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Scopus, Web of Science, Biosis Previews, CINAHL, Allied and Complementary Medicine Database, ERIC, Education Full Text, CBCA Education, Career and Technical Education @ Scholars Portal, Education Abstracts @ Scholars Portal, Expanded Academic ASAP @ Scholars Portal, ACM Digital Library, IEEE Xplore, Abstracts in New Technologies and Engineering and Computer & Information Systems Abstracts. The grey literature until November 2011 was also searched. Randomised and quasi-randomised clinical trials comparing virtual reality endoscopy (oesophagogastroduodenoscopy, colonoscopy and sigmoidoscopy) simulation training versus any other method of endoscopy training including conventional patient-based training, in-job training, training using another form of endoscopy simulation (e.g. low-fidelity simulator), or no training (however defined by authors) were included. Trials comparing one method of virtual reality training versus another method of virtual reality training (e.g. comparison of two different virtual reality simulators) were also included. Only trials measuring outcomes on humans in the clinical setting (as opposed to animals or simulators) were included. Two authors (CMS, MES) independently assessed the eligibility and methodological quality of trials, and extracted data on the trial characteristics and outcomes. Due to significant clinical and methodological heterogeneity it was not possible to pool study data in order to perform a meta-analysis. Where data were available for each continuous outcome we calculated standardized mean difference with 95% confidence intervals based on intention-to-treat analysis. Where data were available for dichotomous outcomes we calculated relative risk with 95% confidence intervals based on intention-to-treat-analysis. Thirteen trials, with 278 participants, met the inclusion criteria. Four trials compared simulation-based training with conventional patient-based endoscopy training (apprenticeship model) whereas nine trials compared simulation-based training with no training. Only three trials were at low risk of bias. Simulation-based training, as compared with no training, generally appears to provide participants with some advantage over their untrained peers as measured by composite score of competency, independent procedure completion, performance time, independent insertion depth, overall rating of performance or competency error rate and mucosal visualization. Alternatively, there was no conclusive evidence that simulation-based training was superior to conventional patient-based training, although data were limited. The results of this systematic review indicate that virtual reality endoscopy training can be used to effectively supplement early conventional endoscopy training (apprenticeship model) in diagnostic oesophagogastroduodenoscopy, colonoscopy and/or sigmoidoscopy for health professions trainees with limited or no prior endoscopic experience. However, there remains insufficient evidence to advise for or against the use of virtual reality simulation-based training as a replacement for early conventional endoscopy training (apprenticeship model) for health professions trainees with limited or no prior endoscopic experience. There is a great need for the development of a reliable and valid measure of endoscopic performance prior to the completion of further randomised clinical trials with high methodological quality.
Use of regularly scheduled albuterol treatment in asthma: genotype-stratified, randomised, placebo-controlled cross-over trial.

PubMed

Israel, Elliot; Chinchilli, Vernon M; Ford, Jean G; Boushey, Homer A; Cherniack, Reuben; Craig, Timothy J; Deykin, Aaron; Fagan, Joanne K; Fahy, John V; Fish, James; Kraft, Monica; Kunselman, Susan J; Lazarus, Stephen C; Lemanske, Robert F; Liggett, Stephen B; Martin, Richard J; Mitra, Nandita; Peters, Stephen P; Silverman, Eric; Sorkness, Christine A; Szefler, Stanley J; Wechsler, Michael E; Weiss, Scott T; Drazen, Jeffrey M

The issue of whether regular use of an inhaled beta2-adrenergic agonist worsens airflow and clinical outcomes in asthma is controversial. Retrospective studies have suggested that adverse effects occur in patients with a genetic polymorphism that results in homozygosity for arginine (Arg/Arg), rather than glycine (Gly/Gly), at aminoacid residue 16 of the beta2-adrenergic receptor. However, the existence of any genotype-dependent difference has not been tested in a prospective clinical trial. Patients with mild asthma, not using a controller medication, were enrolled in pairs matched for forced expiratory volume in 1 s (FEV1) according to whether they had the Arg/Arg (n=37; four of 41 matches withdrew before randomisation) or Gly/Gly (n=41) genotype. Regularly scheduled treatment with albuterol or placebo was given in a masked, cross-over design, for 16-week periods. During the study, as-needed albuterol use was discontinued and ipratropium bromide was used as needed. Morning peak expiratory flow rate (PEFR) was the primary outcome variable. The primary comparisons were between treatment period for each genotype; the secondary outcome was a treatment by genotype effect. Analyses were by intention to treat. During the run-in period, when albuterol use was kept to a minimum, patients with the Arg/Arg genotype had an increase in morning PEFR of 23 L/min (p=0.0162); the change in patients with the Gly/Gly genotype was not significant (2 L/min; p=0.8399). During randomised treatment, patients with the Gly/Gly genotype had an increase in morning PEFR during treatment with regularly scheduled albuterol compared with placebo (14 L/min [95% CI 3 to 25]; p=0.0175). By contrast, patients with the Arg/Arg genotype had lower morning PEFR during treatment with albuterol than during the placebo period, when albuterol use was limited (-10 L/min [-19 to -2]; p=0.0209). The genotype-attributable treatment difference was therefore -24 L/min (-37 to -12; p=0.0003). There were similar genotype-specific effects in FEV1, symptoms, and use of supplementary reliever medication. Genotype at the 16th aminoacid residue of the beta2-adrenergic receptor affects the long-term response to albuterol use. Bronchodilator treatments avoiding albuterol may be appropriate for patients with the Arg/Arg genotype.
Robust spectral-domain optical coherence tomography speckle model and its cross-correlation coefficient analysis

PubMed Central

Liu, Xuan; Ramella-Roman, Jessica C.; Huang, Yong; Guo, Yuan; Kang, Jin U.

2013-01-01

In this study, we proposed a generic speckle simulation for optical coherence tomography (OCT) signal, by convolving the point spread function (PSF) of the OCT system with the numerically synthesized random sample field. We validated our model and used the simulation method to study the statistical properties of cross-correlation coefficients (XCC) between Ascans which have been recently applied in transverse motion analysis by our group. The results of simulation show that over sampling is essential for accurate motion tracking; exponential decay of OCT signal leads to an under estimate of motion which can be corrected; lateral heterogeneity of sample leads to an over estimate of motion for a few pixels corresponding to the structural boundary. PMID:23456001
Cluster randomised trials in the medical literature: two bibliometric surveys

PubMed Central

Bland, J Martin

2004-01-01

Background Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. Methods Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. Results There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. Conclusion Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works. PMID:15310402
Quantity, topics, methods and findings of randomised controlled trials published by German university departments of general practice - systematic review.

PubMed

Heinmüller, Stefan; Schneider, Antonius; Linde, Klaus

2016-04-23

Academic infrastructures and networks for clinical research in primary care receive little funding in Germany. We aimed to provide an overview of the quantity, topics, methods and findings of randomised controlled trials published by German university departments of general practice. We searched Scopus (last search done in April 2015), publication lists of institutes and references of included articles. We included randomised trials published between January 2000 and December 2014 with a first or last author affiliated with a German university department of general practice or family medicine. Risk of bias was assessed with the Cochrane tool, and study findings were quantified using standardised mean differences (SMDs). Thirty-three trials met the inclusion criteria. Seventeen were cluster-randomised trials, with a majority investigating interventions aimed at improving processes compared with usual care. Sample sizes varied between 6 and 606 clusters and 168 and 7807 participants. The most frequent methodological problem was risk of selection bias due to recruitment of individuals after randomisation of clusters. Effects of interventions over usual care were mostly small (SMD <0.3). Sixteen trials randomising individual participants addressed a variety of treatment and educational interventions. Sample sizes varied between 20 and 1620 participants. The methodological quality of the trials was highly variable. Again, effects of experimental interventions over controls were mostly small. Despite limited funding, German university institutes of general practice or family medicine are increasingly performing randomised trials. Cluster-randomised trials on practice improvement are a focus, but problems with allocation concealment are frequent.
Adaptive servo ventilation for central sleep apnoea in heart failure: SERVE-HF on-treatment analysis.

PubMed

Woehrle, Holger; Cowie, Martin R; Eulenburg, Christine; Suling, Anna; Angermann, Christiane; d'Ortho, Marie-Pia; Erdmann, Erland; Levy, Patrick; Simonds, Anita K; Somers, Virend K; Zannad, Faiez; Teschler, Helmut; Wegscheider, Karl

2017-08-01

This on-treatment analysis was conducted to facilitate understanding of mechanisms underlying the increased risk of all-cause and cardiovascular mortality in heart failure patients with reduced ejection fraction and predominant central sleep apnoea randomised to adaptive servo ventilation versus the control group in the SERVE-HF trial.Time-dependent on-treatment analyses were conducted (unadjusted and adjusted for predictive covariates). A comprehensive, time-dependent model was developed to correct for asymmetric selection effects (to minimise bias).The comprehensive model showed increased cardiovascular death hazard ratios during adaptive servo ventilation usage periods, slightly lower than those in the SERVE-HF intention-to-treat analysis. Self-selection bias was evident. Patients randomised to adaptive servo ventilation who crossed over to the control group were at higher risk of cardiovascular death than controls, while control patients with crossover to adaptive servo ventilation showed a trend towards lower risk of cardiovascular death than patients randomised to adaptive servo ventilation. Cardiovascular risk did not increase as nightly adaptive servo ventilation usage increased.On-treatment analysis showed similar results to the SERVE-HF intention-to-treat analysis, with an increased risk of cardiovascular death in heart failure with reduced ejection fraction patients with predominant central sleep apnoea treated with adaptive servo ventilation. Bias is inevitable and needs to be taken into account in any kind of on-treatment analysis in positive airway pressure studies. Copyright ©ERS 2017.
High phenylalanine levels directly affect mood and sustained attention in adults with phenylketonuria: a randomised, double-blind, placebo-controlled, crossover trial.

PubMed

ten Hoedt, Amber E; de Sonneville, Leo M J; Francois, Baudouin; ter Horst, Nienke M; Janssen, Mirian C H; Rubio-Gozalbo, M Estela; Wijburg, Frits A; Hollak, Carla E M; Bosch, Annet M

2011-02-01

The main debate in the treatment of Phenylketonuria (PKU) is whether adult patients need the strict phenylalanine (Phe)-restricted diet. Physicians and patients lack evidence-based guidelines to help them make well-informed choices. We have carried out the first randomised double-blind placebo-controlled trial into the effects of short-term elevation of Phe levels on neuropsychological functions and mood of adults with PKU. Nine continuously treated adults with PKU underwent two 4-week supplementation periods: one with Phe, mimicking normal dietary intake, and one with placebo in randomly allocated order via a randomisation coding list in a double-blind cross-over design. A set of neuropsychological tests (Amsterdam Neuropsychological Tasks) was administered at the end of each study period. In addition, patients and for each patient a friend or relative, completed weekly Profile of Mood States (POMS) questionnaires, evaluating the patients' mood. Phe levels were measured twice weekly. Mean plasma Phe levels were significantly higher during Phe supplementation compared with placebo (p = 0.008). Neuropsychological tests demonstrated an impairment in sustained attention during Phe supplementation (p = 0.029). Both patients and their friend or relative reported lower scores on the POMS questionnaires during Phe supplementation (p = 0.017 and p = 0.040, respectively). High plasma Phe levels have a direct negative effect on both sustained attention and on mood in adult patients with PKU. A Phe-restricted "diet for life" might be an advisable option for many.
Clinical efficiency in a simulated emergency and relationship to team behaviours: a multisite cross-sectional study.

PubMed

Siassakos, D; Bristowe, K; Draycott, T J; Angouri, J; Hambly, H; Winter, C; Crofts, J F; Hunt, L P; Fox, R

2011-04-01

To identify specific aspects of teamworking associated with greater clinical efficiency in simulated obstetric emergencies. Cross-sectional secondary analysis of video recordings from the Simulation & Fire-drill Evaluation (SaFE) randomised controlled trial. Six secondary and tertiary maternity units. A total of 114 randomly selected healthcare professionals, in 19 teams of six members. Two independent assessors, a clinician and a language communication specialist identified specific teamwork behaviours using a grid derived from the safety literature. Relationship between teamwork behaviours and the time to administration of magnesium sulfate, a validated measure of clinical efficiency, was calculated. More efficient teams were likely to (1) have stated (recognised and verbally declared) the emergency (eclampsia) earlier (Kendall's rank correlation coefficient τ(b) = -0.53, 95% CI from -0.74 to -0.32, P=0.004); and (2) have managed the critical task using closed-loop communication (task clearly and loudly delegated, accepted, executed and completion acknowledged) (τ(b) = 0.46, 95% CI 0.17-0.74, P=0.022). Teams that administered magnesium sulfate within the allocated time (10 minutes) had significantly fewer exits from the labour room compared with teams who did not: a median of three (IQR 2-5) versus six exits (IQR 5-6) (P=0.03, Mann-Whitney U-test). Using administration of an essential drug as a valid surrogate of team efficiency and patient outcome after a simulated emergency, we found that more efficient teams were more likely to exhibit certain team behaviours relating to better handover and task allocation. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.
Creatine for women in pregnancy for neuroprotection of the fetus.

PubMed

Dickinson, Hayley; Bain, Emily; Wilkinson, Dominic; Middleton, Philippa; Crowther, Caroline A; Walker, David W

2014-12-19

Creatine is an amino acid derivative and, when phosphorylated (phosphocreatine), is involved in replenishing adenosine triphosphate (ATP) via the creatine kinase reaction. Cells obtain creatine from a diet rich in fish, meat, or dairy and by endogenous synthesis from the amino acids arginine, glycine, and methionine in an approximate 50:50 ratio. Animal studies have shown that creatine may provide fetal neuroprotection when given to the mother through her diet in pregnancy. It is important to assess whether maternally administered creatine in human pregnancy (at times of known, suspected, or potential fetal compromise) may offer neuroprotection to the fetus and may accordingly reduce the risk of adverse neurodevelopmental outcomes, such as cerebral palsy and associated impairments and disabilities arising from fetal brain injury. To assess the effects of creatine when used for neuroprotection of the fetus. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2014). We planned to include all published, unpublished, and ongoing randomised trials and quasi-randomised trials. We planned to include studies reported as abstracts only as well as full-text manuscripts. Trials using a cross-over or cluster-randomised design were not eligible for inclusion.We planned to include trials comparing creatine given to women in pregnancy for fetal neuroprotection (regardless of the route, timing, dose, or duration of administration) with placebo, no treatment, or with an alternative agent aimed at providing fetal neuroprotection. We also planned to include comparisons of different regimens for administration of creatine. We identified no completed or ongoing randomised controlled trials. We found no randomised controlled trials for inclusion in this review. As we did not identify any randomised controlled trials for inclusion in this review, we are unable to comment on implications for practice. Although evidence from animal studies has supported a fetal neuroprotective role for creatine when administered to the mother during pregnancy, no trials assessing creatine in pregnant women for fetal neuroprotection have been published to date. If creatine is established as safe for the mother and her fetus, research efforts should first be directed towards randomised trials comparing creatine with either no intervention (ideally using a placebo), or with alternative agents aimed at providing fetal neuroprotection (including magnesium sulphate for the very preterm infant). If appropriate, these trials should then be followed by studies comparing different creatine regimens (dosage and duration of exposure). Such trials should be high quality and adequately powered to evaluate maternal and infant short and longer-term outcomes (including neurodevelopmental disabilities such as cerebral palsy), and should consider utilisation/costs of health care.
The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial.

PubMed

Battelino, T; Conget, I; Olsen, B; Schütz-Fuhrmann, I; Hommel, E; Hoogma, R; Schierloh, U; Sulli, N; Bolinder, J

2012-12-01

The aim of this multicentre, randomised, controlled crossover study was to determine the efficacy of adding continuous glucose monitoring (CGM) to insulin pump therapy (CSII) in type 1 diabetes. Children and adults (n = 153) on CSII with HbA(1c) 7.5-9.5% (58.5-80.3 mmol/mol) were randomised to (CGM) a Sensor On or Sensor Off arm for 6 months. After 4 months' washout, participants crossed over to the other arm for 6 months. Paediatric and adult participants were separately electronically randomised through the case report form according to a predefined randomisation sequence in eight secondary and tertiary centres. The primary outcome was the difference in HbA(1c) levels between arms after 6 months. Seventy-seven participants were randomised to the On/Off sequence and 76 to the Off/On sequence; all were included in the primary analysis. The mean difference in HbA(1c) was -0.43% (-4.74 mmol/mol) in favour of the Sensor On arm (8.04% [64.34 mmol/mol] vs 8.47% [69.08 mmol/mol]; 95% CI -0.32%, -0.55% [-3.50, -6.01 mmol/mol]; p < 0.001). Following cessation of glucose sensing, HbA(1c) reverted to baseline levels. Less time was spent with sensor glucose <3.9 mmol/l during the Sensor On arm than in the Sensor Off arm (19 vs 31 min/day; p = 0.009). The mean number of daily boluses increased in the Sensor On arm (6.8 ± 2.5 vs 5.8 ± 1.9, p < 0.0001), together with the frequency of use of the temporary basal rate (0.75 ± 1.11 vs 0.26 ± 0.47, p < 0.0001) and manual insulin suspend (0.91 ± 1.25 vs 0.70 ± 0.75, p < 0.018) functions. Four vs two events of severe hypoglycaemia occurred in the Sensor On and Sensor Off arm, respectively (p = 0.40). Continuous glucose monitoring was associated with decreased HbA(1c) levels and time spent in hypoglycaemia in individuals with type 1 diabetes using CSII. More frequent self-adjustments of insulin therapy may have contributed to these effects.
Understanding the cluster randomised crossover design: a graphical illustraton of the components of variation and a sample size tutorial.

PubMed

Arnup, Sarah J; McKenzie, Joanne E; Hemming, Karla; Pilcher, David; Forbes, Andrew B

2017-08-15

In a cluster randomised crossover (CRXO) design, a sequence of interventions is assigned to a group, or 'cluster' of individuals. Each cluster receives each intervention in a separate period of time, forming 'cluster-periods'. Sample size calculations for CRXO trials need to account for both the cluster randomisation and crossover aspects of the design. Formulae are available for the two-period, two-intervention, cross-sectional CRXO design, however implementation of these formulae is known to be suboptimal. The aims of this tutorial are to illustrate the intuition behind the design; and provide guidance on performing sample size calculations. Graphical illustrations are used to describe the effect of the cluster randomisation and crossover aspects of the design on the correlation between individual responses in a CRXO trial. Sample size calculations for binary and continuous outcomes are illustrated using parameters estimated from the Australia and New Zealand Intensive Care Society - Adult Patient Database (ANZICS-APD) for patient mortality and length(s) of stay (LOS). The similarity between individual responses in a CRXO trial can be understood in terms of three components of variation: variation in cluster mean response; variation in the cluster-period mean response; and variation between individual responses within a cluster-period; or equivalently in terms of the correlation between individual responses in the same cluster-period (within-cluster within-period correlation, WPC), and between individual responses in the same cluster, but in different periods (within-cluster between-period correlation, BPC). The BPC lies between zero and the WPC. When the WPC and BPC are equal the precision gained by crossover aspect of the CRXO design equals the precision lost by cluster randomisation. When the BPC is zero there is no advantage in a CRXO over a parallel-group cluster randomised trial. Sample size calculations illustrate that small changes in the specification of the WPC or BPC can increase the required number of clusters. By illustrating how the parameters required for sample size calculations arise from the CRXO design and by providing guidance on both how to choose values for the parameters and perform the sample size calculations, the implementation of the sample size formulae for CRXO trials may improve.
The effectiveness and safety of combining varenicline with nicotine e-cigarettes for smoking cessation in people with mental illnesses and addictions: study protocol for a randomised-controlled trial.

PubMed

Bullen, Chris; Verbiest, Marjolein; Galea-Singer, Susanna; Kurdziel, Tomasz; Laking, George; Newcombe, David; Parag, Varsha; Walker, Natalie

2018-05-04

Smoking rates are higher in New Zealand (NZ) adults with mental illnesses and alcohol and other drug (AOD) addictions, compared to the overall population. Quit attempts using "gold standard" smoking cessation treatments often fail in people with these conditions, so more flexible treatment regimens that adapt to a person's responsiveness to treatment are worth investigating. The STATUS trial aims to evaluate the effectiveness and safety of combining varenicline with nicotine e-cigarettes for smoking cessation among varenicline non-responders in treatment for mental health illnesses and/or AOD addictions. This is a pragmatic two-arm, open-label, randomised trial. Participants will be daily smokers using mental health and/or addiction services in Auckland, aged ≥18 years, motivated to quit smoking, and eligible to access varenicline through the NZ special authority process. After 2 weeks of using varenicline plus behavioural support, participants who have not reduced their daily smoking by ≥50% will be randomised (1:1) to either 10 weeks of continued varenicline use or 10 weeks of varenicline plus an 18 mg/mL nicotine e-cigarette. All participants will receive weekly withdrawal-orientated behavioural support calls for 6 weeks post-randomisation. The primary outcome is self-reported biochemically-verified (exhaled carbon monoxide) continuous abstinence at 24 weeks post-randomisation. Secondary outcomes, measured at six, 12 and 24 weeks post-randomisation include: self-reported continuous abstinence, 7-day point prevalence abstinence, smoking reduction, time to relapse, cross-over, use of other smoking cessation support, serious adverse events, treatment adherence, compliance, acceptability, dual use, continuation of treatment use, mental illness symptoms and AOD use, health-related quality of life, and cost-analysis. A sample size of 338 will confer 80% power (p = 0.05) to detect a 15% absolute difference between the varenicline alone and varenicline plus e-cigarette groups. People with mental illness and/or AOD addictions are just as motivated as others to quit smoking, but are less likely to succeed. Adapting smoking cessation medication after a lack of responsiveness in the first 2 weeks of initial treatment in this priority population by adding a nicotine e-cigarette may be one way to increase long-term quit rates. Australian NZ Clinical Trial Registry: ACTRN12616001355460 (29 September 2016).
Screening versus routine practice in detection of atrial fibrillation in patients aged 65 or over: cluster randomised controlled trial

PubMed Central

Fitzmaurice, David A; Jowett, Sue; Mant, Jonathon; Murray, Ellen T; Holder, Roger; Raftery, J P; Bryan, S; Davies, Michael; Lip, Gregory Y H; Allan, T F

2007-01-01

Objectives To assess whether screening improves the detection of atrial fibrillation (cluster randomisation) and to compare systematic and opportunistic screening. Design Multicentred cluster randomised controlled trial, with subsidiary trial embedded within the intervention arm. Setting 50 primary care centres in England, with further individual randomisation of patients in the intervention practices. Participants 14 802 patients aged 65 or over in 25 intervention and 25 control practices. Interventions Patients in intervention practices were randomly allocated to systematic screening (invitation for electrocardiography) or opportunistic screening (pulse taking and invitation for electrocardiography if the pulse was irregular). Screening took place over 12 months in each practice from October 2001 to February 2003. No active screening took place in control practices. Main outcome measure Newly identified atrial fibrillation. Results The detection rate of new cases of atrial fibrillation was 1.63% a year in the intervention practices and 1.04% in control practices (difference 0.59%, 95% confidence interval 0.20% to 0.98%). Systematic and opportunistic screening detected similar numbers of new cases (1.62% v 1.64%, difference 0.02%, −0.5% to 0.5%). Conclusion Active screening for atrial fibrillation detects additional cases over current practice. The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography. Trial registration Current Controlled Trials ISRCTN19633732. PMID:17673732
The metabolic consequences of infusing emulsions containing medium chain triglycerides for parenteral nutrition: a comparative study with conventional lipid.

PubMed Central

Dennison, A. R.; Ball, M.; Crowe, P. J.; White, K.; Hands, L.; Watkins, R. M.; Kettlewell, M.

1986-01-01

In order to test the hypothesis that medium chain triglycerides (MCT's) are a safe and potentially superior energy source during parenteral nutrition 13 patients were entered into a randomised cross over trial. They received either a long chain triglyceride emulsion (LCT) or a 50% medium chain (MCT)/50% LCT mixture as part of their energy supply. Nitrogen balance was significantly better when MCT/LCT was infused and the greater levels of plasma ketones and lower plasma triglyceride levels suggested that MCT was more readily metabolised in these patients. Routine haematology, biochemistry and liver function tests gave no indication of harmful side effects from MCT. PMID:3089123
Almond-Shaped Test Body

NASA Technical Reports Server (NTRS)

Dominek, Allen; Wood, Richard; Gilreath, Mel

1992-01-01

Almond shaped test body developed for use in electromagnetic anechoic chamber for evaluation of range and measurement of components has low radar cross section that varies with angle over large dynamic range. Surface is composite formed by joining properly scaled ellipsoidal surfaces. Used to mount components whose radar cross sections are to be measured, and simulate backscatter characteristics of component as though it were over infinite ground plane.
An approach to combining parallel and cross-over trials with and without run-in periods using individual patient data.

PubMed

Tvete, Ingunn F; Olsen, Inge C; Fagerland, Morten W; Meland, Nils; Aldrin, Magne; Smerud, Knut T; Holden, Lars

2012-04-01

In active run-in trials, where patients may be excluded after a run-in period based on their response to the treatment, it is implicitly assumed that patients have individual treatment effects. If individual patient data are available, active run-in trials can be modelled using patient-specific random effects. With more than one trial on the same medication available, one can obtain a more precise overall treatment effect estimate. We present a model for joint analysis of a two-sequence, four-period cross-over trial (AABB/BBAA) and a three-sequence, two-period active run-in trial (AB/AA/A), where the aim is to investigate the effect of a new treatment for patients with pain due to osteoarthritis. Our approach enables us to separately estimate the direct treatment effect for all patients, for the patients excluded after the active run-in trial prior to randomisation, and for the patients who completed the active run-in trial. A similar model approach can be used to analyse other types of run-in trials, but this depends on the data and type of other trials available. We assume equality of the various carry-over effects over time. The proposed approach is flexible and can be modified to handle other designs. Our results should be encouraging for those responsible for planning cost-efficient clinical development programmes.
Quasielastic neutron scattering measurements and ab initio MD-simulations on single ion motions in molten NaF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demmel, F.; Mukhopadhyay, S.; Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ

2016-01-07

The ionic stochastic motions in the molten alkali halide NaF are investigated by quasielastic neutron scattering and first principles molecular dynamics simulation. Quasielastic neutron scattering was employed to extract the diffusion behavior of the sodium ions in the melt. An extensive first principles based simulation on a box of up to 512 particles has been performed to complement the experimental data. From that large box, a smaller 64-particle box has then been simulated over a runtime of 60 ps. A good agreement between calculated and neutron data on the level of spectral shape has been obtained. The obtained sodium diffusionmore » coefficients agree very well. The simulation predicts a fluorine diffusion coefficient similar to the sodium one. Applying the Nernst-Einstein equation, a remarkable large cross correlation between both ions can be deduced. The velocity cross correlations demonstrate a positive correlation between the ions over a period of 0.1 ps. That strong correlation is evidence that the unlike ions do not move completely statistically independent and have a strong association over a short period of time.« less
Improving health-related fitness in adolescents: the CrossFit Teens™ randomised controlled trial.

PubMed

Eather, Narelle; Morgan, Philip James; Lubans, David Revalds

2016-01-01

The aim of this study was to evaluate the preliminary efficacy and feasibility of the CrossFit Teens™ resistance training programme for improving health-related fitness and resistance training skill competency in adolescents. This assessor-blinded randomised controlled trial was conducted in one secondary school in the Hunter Region, Australia, from July to September 2013. Ninety-six (96) students (age = 15.4 (.5) years, 51.5% female) were randomised into intervention (n = 51) or control (n = 45) conditions for 8-weeks (60 min twice per week). Waist circumference, body mass index (BMI), BMI-Z score (primary outcomes), cardiorespiratory fitness (shuttle run test), muscular fitness (standing jump, push-up, handgrip, curl-up test), flexibility (sit and reach) and resistance training skill competency were measured at baseline and immediate post-intervention. Feasibility measures of recruitment, retention, adherence and satisfaction were assessed. Significant group-by-time intervention effects were found for waist circumference [-3.1 cm, P < 0.001], BMI [-1.38 kg · m(‒)(2), P < 0.001], BMI-Z [-0.5 z-scores, P < 0.001], sit and reach [+3.0 cm, P < 0.001], standing jump [+0.1 m, P = 0.021] and shuttle run [+10.3 laps, P = 0.019]. Retention rate was 82.3%. All programme sessions were delivered and participants' mean satisfaction scores ranged from 4.2 to 4.6 out of 5. The findings demonstrate that CrossFit Teens™ is a feasible and efficacious programme for improving health-related fitness in adolescents.
Acceptability and Feasibility of Cash Transfers for HIV Prevention among Adolescent South African Women

PubMed Central

MacPhail, Catherine; Adato, Michelle; Kahn, Kathleen; Selin, Amanda; Twine, Rhian; Khoza, Samson; Rosenberg, Molly; Nguyen, Nadia; Becker, Elizabeth; Pettifor, Audrey

2013-01-01

Women are at increased risk of HIV infection in much of sub-Saharan Africa. Longitudinal and cross-sectional studies have found an association between school attendance and reduced HIV risk. We report feasibility and acceptability results from a pilot of a cash transfer intervention conditional on school attendance paid to young women and their families in rural Mpumalanga, South Africa for the prevention of HIV infection. Twenty-nine young women were randomised to intervention or control and a cash payment based on school attendance made over a 2 month period. Quantitative (survey) and qualitative (focus group and interview) data collection was undertaken with young women, parents, teachers and young men in the same school. Qualitative analysis was conducted in Atlas.ti using a framework approach and basic descriptive analysis in Excel was conducted on the quantitative data. Results indicate it was both feasible and acceptable to introduce such an intervention among this population in rural South Africa. There was good understanding of the process of randomisation and the aims of the study, although some rumours developed in the study community. We address some of the changes necessary to ensure acceptability and feasibility of the main trial. PMID:23435698

Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial

PubMed Central

Sørensen, Jette Led; van der Vleuten, Cees; Rosthøj, Susanne; Østergaard, Doris; LeBlanc, Vicki; Johansen, Marianne; Ekelund, Kim; Starkopf, Liis; Lindschou, Jane; Gluud, Christian; Weikop, Pia; Ottesen, Bent

2015-01-01

Objective To investigate the effect of in situ simulation (ISS) versus off-site simulation (OSS) on knowledge, patient safety attitude, stress, motivation, perceptions of simulation, team performance and organisational impact. Design Investigator-initiated single-centre randomised superiority educational trial. Setting Obstetrics and anaesthesiology departments, Rigshospitalet, University of Copenhagen, Denmark. Participants 100 participants in teams of 10, comprising midwives, specialised midwives, auxiliary nurses, nurse anaesthetists, operating theatre nurses, and consultant doctors and trainees in obstetrics and anaesthesiology. Interventions Two multiprofessional simulations (clinical management of an emergency caesarean section and a postpartum haemorrhage scenario) were conducted in teams of 10 in the ISS versus the OSS setting. Primary outcome Knowledge assessed by a multiple choice question test. Exploratory outcomes Individual outcomes: scores on the Safety Attitudes Questionnaire, stress measurements (State-Trait Anxiety Inventory, cognitive appraisal and salivary cortisol), Intrinsic Motivation Inventory and perceptions of simulations. Team outcome: video assessment of team performance. Organisational impact: suggestions for organisational changes. Results The trial was conducted from April to June 2013. No differences between the two groups were found for the multiple choice question test, patient safety attitude, stress measurements, motivation or the evaluation of the simulations. The participants in the ISS group scored the authenticity of the simulation significantly higher than did the participants in the OSS group. Expert video assessment of team performance showed no differences between the ISS versus the OSS group. The ISS group provided more ideas and suggestions for changes at the organisational level. Conclusions In this randomised trial, no significant differences were found regarding knowledge, patient safety attitude, motivation or stress measurements when comparing ISS versus OSS. Although participant perception of the authenticity of ISS versus OSS differed significantly, there were no differences in other outcomes between the groups except that the ISS group generated more suggestions for organisational changes. Trial registration number NCT01792674. PMID:26443654
Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial.

PubMed

Souday, Vincent; Koning, Nick J; Perez, Bruno; Grelon, Fabien; Mercat, Alain; Boer, Christa; Seegers, Valérie; Radermacher, Peter; Asfar, Pierre

2016-01-01

To test the hypothesis whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression. Human volunteers underwent a first simulated dive breathing compressed air to include subjects prone to post-decompression venous gas bubbling. Twelve subjects prone to bubbling underwent a double-blind, randomized, cross-over trial including one simulated dive breathing compressed air, and one dive breathing EAN (36% O2) in a hyperbaric chamber, with identical diving profiles (28 msw for 55 minutes). Intravascular bubble formation was assessed after decompression using pulmonary artery pulsed Doppler. Twelve subjects showing high bubble production were included for the cross-over trial, and all completed the experimental protocol. In the randomized protocol, EAN significantly reduced the bubble score at all time points (cumulative bubble scores: 1 [0-3.5] vs. 8 [4.5-10]; P < 0.001). Three decompression incidents, all presenting as cutaneous itching, occurred in the air versus zero in the EAN group (P = 0.217). Weak correlations were observed between bubble scores and age or body mass index, respectively. EAN breathing markedly reduces venous gas bubble emboli after decompression in volunteers selected for susceptibility for intravascular bubble formation. When using similar diving profiles and avoiding oxygen toxicity limits, EAN increases safety of diving as compared to compressed air breathing. ISRCTN 31681480.
Future Modelling and Simulation Challenges (Defis futurs pour la modelisation et la simulation)

DTIC Science & Technology

2002-11-01

Language School Figure 2: Location of the simulation center within the MEC Military operations research section - simulation lab Military operations... language . This logic can be probabilistic (branching is randomised, which is useful for modelling error), tactical (a branch goes to the task with the... language and a collection of simulation tools that can be used to create human and team behaviour models to meet users’ needs. Hence, different ways of
Splint: the efficacy of orthotic management in rest to prevent equinus in children with cerebral palsy, a randomised controlled trial.

PubMed

Maas, Josina C; Dallmeijer, Annet J; Huijing, Peter A; Brunstrom-Hernandez, Janice E; van Kampen, Petra J; Jaspers, Richard T; Becher, Jules G

2012-03-26

Range of motion deficits of the lower extremity occur in about the half of the children with spastic cerebral palsy (CP). Over time, these impairments can cause joint deformities and deviations in the children's gait pattern, leading to limitations in moblity. Preventing a loss of range of motion is important in order to reduce secondary activity limitations and joint deformities. Sustained muscle stretch, imposed by orthotic management in rest, might be an effective method of preventing a decrease in range of motion. However, no controlled study has been performed. A single blind randomised controlled trial will be performed in 66 children with spastic CP, divided over three groups with each 22 participants. Two groups will be treated for 1 year with orthoses to prevent a decrease in range of motion in the ankle (either with static or dynamic knee-ankle-foot-orthoses) and a third group will be included as a control group and will receive usual care (physical therapy, manual stretching). Measurements will be performed at baseline and at 3, 6, 9 and 12 months after treatment allocation. The primary outcome measure will be ankle dorsiflexion at full knee extension, measured with a custom designed hand held dynamometer. Secondary outcome measures will be i) ankle and knee flexion during gait and ii) gross motor function. Furthermore, to gain more insight in the working mechanism of the orthotic management in rest, morphological parameters like achilles tendon length, muscle belly length, muscle fascicle length, muscle physiological cross sectional area length and fascicle pennation angle will be measured in a subgroup of 18 participants using a 3D imaging technique. This randomised controlled trial will provide more insight into the efficacy of orthotic management in rest and the working mechanisms behind this treatment. The results of this study could lead to improved treatments. Nederlands Trial Register NTR2091.
Post-prandial reflux suppression by a raft-forming alginate (Gaviscon Advance) compared to a simple antacid documented by magnetic resonance imaging and pH-impedance monitoring: mechanistic assessment in healthy volunteers and randomised, controlled, double-blind study in reflux patients.

PubMed

Sweis, R; Kaufman, E; Anggiansah, A; Wong, T; Dettmar, P; Fried, M; Schwizer, W; Avvari, R K; Pal, A; Fox, M

2013-06-01

Alginates form a raft above the gastric contents, which may suppress gastro-oesophageal reflux; however, inconsistent effects have been reported in mechanistic and clinical studies. To visualise reflux suppression by an alginate-antacid [Gaviscon Advance (GA), Reckitt Benckiser, UK] compared with a nonraft-forming antacid using magnetic resonance imaging (MRI), and to determine the feasibility of pH-impedance monitoring for assessment of reflux suppression by alginates. Two studies were performed: (i) GA and antacid (Alucol, Wander Ltd, Switzerland) were visualised in the stomach after ingestion in 12 healthy volunteers over 30 min after a meal by MRI, with reflux events documented by manometry. (ii) A randomised controlled, double-blind cross-over trial of post-prandial reflux suppression documented by pH-impedance in 20 patients randomised to GA or antacid (Milk of Magnesia; Boots, UK) after two meals taken 24 h apart. MRI visualized a "mass" of GA form at the oesophago-gastric junction (OGJ); simple antacid sank to the distal stomach. The number of post-prandial common cavity reflux events was less with GA than antacid [median 2 (0-5) vs. 5 (1-11); P < 0.035]. Distal reflux events and acid exposure measured by pH-impedance were similar after GA and antacid. There was a trend to reduced proximal reflux events with GA compared with antacid [10.5 (8.9) vs. 13.9 (8.3); P = 0.070]. Gaviscon Advance forms a 'mass' close to the OGJ and significantly suppresses reflux compared with a nonraft-forming antacid. Standard pH-impedance monitoring is suitable for clinical studies of GA in gastro-oesophageal reflux disease patients where proximal reflux is the primary outcome. © 2013 Blackwell Publishing Ltd.
Computer classes and games in virtual reality environment to reduce loneliness among students of an elderly reference center: Study protocol for a randomised cross-over design.

PubMed

Antunes, Thaiany Pedrozo Campos; Oliveira, Acary Souza Bulle de; Crocetta, Tania Brusque; Antão, Jennifer Yohanna Ferreira de Lima; Barbosa, Renata Thais de Almeida; Guarnieri, Regiani; Massetti, Thais; Monteiro, Carlos Bandeira de Mello; Abreu, Luiz Carlos de

2017-03-01

Physical and mental changes associated with aging commonly lead to a decrease in communication capacity, reducing social interactions and increasing loneliness. Computer classes for older adults make significant contributions to social and cognitive aspects of aging. Games in a virtual reality (VR) environment stimulate the practice of communicative and cognitive skills and might also bring benefits to older adults. Furthermore, it might help to initiate their contact to the modern technology. The purpose of this study protocol is to evaluate the effects of practicing VR games during computer classes on the level of loneliness of students of an elderly reference center. This study will be a prospective longitudinal study with a randomised cross-over design, with subjects aged 50 years and older, of both genders, spontaneously enrolled in computer classes for beginners. Data collection will be done in 3 moments: moment 0 (T0) - at baseline; moment 1 (T1) - after 8 typical computer classes; and moment 2 (T2) - after 8 computer classes which include 15 minutes for practicing games in VR environment. A characterization questionnaire, the short version of the Short Social and Emotional Loneliness Scale for Adults (SELSA-S) and 3 games with VR (Random, MoviLetrando, and Reaction Time) will be used. For the intervention phase 4 other games will be used: Coincident Timing, Motor Skill Analyser, Labyrinth, and Fitts. The statistical analysis will compare the evolution in loneliness perception, performance, and reaction time during the practice of the games between the 3 moments of data collection. Performance and reaction time during the practice of the games will also be correlated to the loneliness perception. The protocol is approved by the host institution's ethics committee under the number 52305215.3.0000.0082. Results will be disseminated via peer-reviewed journal articles and conferences. This clinical trial is registered at ClinicalTrials.gov identifier: NCT02798081.
Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial.

PubMed

Roager, Henrik Munch; Vogt, Josef K; Kristensen, Mette; Hansen, Lea Benedicte S; Ibrügger, Sabine; Mærkedahl, Rasmus B; Bahl, Martin Iain; Lind, Mads Vendelbo; Nielsen, Rikke L; Frøkiær, Hanne; Gøbel, Rikke Juul; Landberg, Rikard; Ross, Alastair B; Brix, Susanne; Holck, Jesper; Meyer, Anne S; Sparholt, Morten H; Christensen, Anders F; Carvalho, Vera; Hartmann, Bolette; Holst, Jens Juul; Rumessen, Jüri Johannes; Linneberg, Allan; Sicheritz-Pontén, Thomas; Dalgaard, Marlene D; Blennow, Andreas; Frandsen, Henrik Lauritz; Villas-Bôas, Silas; Kristiansen, Karsten; Vestergaard, Henrik; Hansen, Torben; Ekstrøm, Claus T; Ritz, Christian; Nielsen, Henrik Bjørn; Pedersen, Oluf Borbye; Gupta, Ramneek; Lauritzen, Lotte; Licht, Tine Rask

2017-11-01

To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation. NCT01731366; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
A mixed diet supplemented with L-arabinose does not alter glycaemic or insulinaemic responses in healthy human subjects.

PubMed

Halschou-Jensen, Kia; Bach Knudsen, Knud E; Nielsen, Søren; Bukhave, Klaus; Andersen, Jens R

2015-01-14

In addition to a yet-to-be published study showing arabinose to have an inhibiting effect on maltase, in vitro studies have shown L-arabinose to exert an inhibiting effect on small-intestinal sucrase and maltase and the consumption of a sucrose-rich drink containing L-arabinose to exert positive effects on postprandial blood glucose, insulin and C-peptide responses in humans. However, the effects of adding L-arabinose to mixed meals on the indices of glucose control are unknown. The purpose of the present study was to investigate whether the positive effects of L-arabinose added to a sugar drink could be reproduced in subjects consuming a mixed meal containing sucrose and/or starch from wheat flour. A total of seventeen healthy men participated in study 1, a randomised, double-blind, cross-over trial. In this study, the subjects consumed two different breakfast meals containing sucrose and starch from wheat flour (meal A) or starch from wheat flour (meal B) supplemented with 0, 5 and 10 % L-arabinose by weight after a 12 h fast. A total of six healthy men participated in study 2, a randomised, double-blind, cross-over trial. In this study, the subjects also consumed meal B served in two different textures and a liquid meal with maltose supplemented with 0 and 20% L-arabinose. In addition, 1·5 g of paracetamol was chosen as an indirect marker to assess gastric emptying. Postprandial plasma glucose, insulin and C-peptide concentrations were measured regularly for 3 h. The results of the present study showed that the peak plasma concentration, time to reach peak plasma concentration or AUC values of glucose, insulin and C-peptide were not altered after consumption of the test meals. Overall, it was not possible to reproduce the beneficial effects of L-arabinose added to sucrose drinks when L-arabinose was mixed in a solid or semi-solid mixed meal.
The effectiveness of healthy meals at work on reaction time, mood and dietary intake: a randomised cross-over study in daytime and shift workers at an university hospital.

PubMed

Leedo, Eva; Beck, Anne Marie; Astrup, Arne; Lassen, Anne D

2017-07-01

Our dietary habits affect both cognitive performance and mood. The aim of the study was to examine the effect of increased availability of healthy meals and water at work on healthcare staff. The study used an 8-week randomised cross-over design. A total of sixty physicians, nurses and nursing assistants, including sixteen working on shifts, were recruited. The participants received a self-selected keyhole-labelled (Nordic nutrition label) lunch, snack and bottled water during each shift throughout the intervention period. Reaction time (Go/No-Go test), mood-related scores (POMS) and dietary intake were assessed at run-in, and at the end of the intervention and the control periods. The intake of fat (P=0·030) and PUFA (P=0·003) was lower, and the intake of carbohydrate (P=0·008), dietary fibre (P=0·031) and water (P<0·001) was greater in the intervention period than in the control period. The intervention had no effect on reaction time or any of the mood-related scores in the group as a whole. In shift-working participants, the intervention period resulted in a 31·1 % lower Fatigue-Inertia Score (P=0·003), a 15·3 % higher Vigour-Activity Score (P=0·041) and a 42·7 % lower Total Mood Disturbance Score (P=0·017), whereas the only dietary component that significantly improved was water intake (P=0·034), when compared with the control period. Providing healthy meals, snacks and water during working hours seems to be an effective way of improving employees' dietary intake. Moreover, increased intake of water may be associated with beneficial effects on fatigue, vigour and total mood in shift-working healthcare staff.
Acute and second-meal effects of peanuts on glycaemic response and appetite in obese women with high type 2 diabetes risk: a randomised cross-over clinical trial.

PubMed

Reis, Caio E G; Ribeiro, Daniela N; Costa, Neuza M B; Bressan, Josefina; Alfenas, Rita C G; Mattes, Richard D

2013-06-01

Nut consumption is associated with a reduced risk of type 2 diabetes mellitus (T2DM). The aim of the present study was to assess the effects of adding peanuts (whole or peanut butter) on first (0-240 min)- and second (240-490 min)-meal glucose metabolism and selected gut satiety hormone responses, appetite ratings and food intake in obese women with high T2DM risk. A group of fifteen women participated in a randomised cross-over clinical trial in which 42·5 g of whole peanuts without skins (WP), peanut butter (PB) or no peanuts (control) were added to a 75 g available carbohydrate-matched breakfast meal. Postprandial concentrations (0-490 min) of glucose, insulin, NEFA, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), cholecystokinin (CCK), appetitive sensations and food intake were assessed after breakfast treatments and a standard lunch. Postprandial NEFA incremental AUC (IAUC) (0-240 min) and glucose IAUC (240-490 min) responses were lower for the PB breakfast compared with the control breakfast. Insulin concentrations were higher at 120 and 370 min after the PB consumption than after the control consumption. Desire-to-eat ratings were lower, while PYY, GLP-1 and CCK concentrations were higher after the PB intake compared with the control intake. WP led to similar but non-significant effects. The addition of PB to breakfast moderated postprandial glucose and NEFA concentrations, enhanced gut satiety hormone secretion and reduced the desire to eat. The greater bioaccessibility of the lipid component in PB is probably responsible for the observed incremental post-ingestive responses between the nut forms. Inclusion of PB, and probably WP, to breakfast may help to moderate glucose concentrations and appetite in obese women.
The effects of Nordic school meals on concentration and school performance in 8- to 11-year-old children in the OPUS School Meal Study: a cluster-randomised, controlled, cross-over trial.

PubMed

Sørensen, Louise B; Dyssegaard, Camilla B; Damsgaard, Camilla T; Petersen, Rikke A; Dalskov, Stine-Mathilde; Hjorth, Mads F; Andersen, Rikke; Tetens, Inge; Ritz, Christian; Astrup, Arne; Lauritzen, Lotte; Michaelsen, Kim F; Egelund, Niels

2015-04-28

It is widely assumed that nutrition can improve school performance in children; however, evidence remains limited and inconclusive. In the present study, we investigated whether serving healthy school meals influenced concentration and school performance of 8- to 11-year-old Danish children. The OPUS (Optimal well-being, development and health for Danish children through a healthy New Nordic Diet) School Meal Study was a cluster-randomised, controlled, cross-over trial comparing a healthy school meal programme with the usual packed lunch from home (control) each for 3 months (NCT 01457794). The d2 test of attention, the Learning Rating Scale (LRS) and standard tests on reading and mathematics proficiency were administered at baseline and at the end of each study period. Intervention effects were evaluated using hierarchical mixed models. The school meal intervention did not influence concentration performance (CP; primary outcome, n 693) or processing speed; however, the decrease in error percentage was 0·18 points smaller (P<0·001) in the intervention period than in the control period (medians: baseline 2·03%; intervention 1·46%; control 1·37%). In contrast, the intervention increased reading speed (0·7 sentence, P=0·009) and the number of correct sentences (1·8 sentences, P<0·001), which corresponded to 11 and 25%, respectively, of the effect of one school year. The percentage of correct sentences also improved (P<0·001), indicating that the number correct improved relatively more than reading speed. There was no effect on overall math performance or outcomes from the LRS. In conclusion, school meals did not affect CP, but improved reading performance, which is a complex cognitive activity that involves inference, and increased errors related to impulsivity and inattention. These findings are worth examining in future trials.
Eradication of early P. aeruginosa infection in children <7 years of age with cystic fibrosis: The early study.

PubMed

Ratjen, Felix; Moeller, Alexander; McKinney, Martha L; Asherova, Irina; Alon, Nipa; Maykut, Robert; Angyalosi, Gerhild

2018-04-20

Antibiotic eradication treatment is the standard-of-care for cystic fibrosis (CF) patients with early Pseudomonas aeruginosa (Pa)-infection; however, evidence from placebo-controlled trials is limited. This double-blind, placebo-controlled trial randomised CF patients <7 years (N = 51) with early Pa-infection to tobramycin inhalation solution (TOBI 300 mg) or placebo (twice daily) for 28 days with an optional cross-over on Day 35. Primary endpoint was proportion of patients having throat swabs/sputum free of Pa on Day 29. On Day 29, 84.6% patients in the TOBI versus 24.0% in the placebo group were Pa-free (p < 0.001). At the end of the cross-over period, 76.0% patients receiving TOBI in the initial 28 days were Pa-free compared to 47.8% receiving placebo initially. Adverse events were consistent with the TOBI safety profile with no differences between TOBI and placebo. TOBI was effective in eradicating early Pa-infection with a favourable safety profile in young CF patients. NCT01082367. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
Seasonal and interannual cross-shelf transport over the Texas and Louisiana continental shelf

NASA Astrophysics Data System (ADS)

Thyng, Kristen M.; Hetland, Robert D.

2018-05-01

Numerical drifters are tracked in a hydrodynamic simulation of circulation over the Texas-Louisiana shelf to analyze patterns in cross-shelf transport of materials. While the important forcing mechanisms in the region (wind, river, and deep eddies) and associated flow patterns are known, the resultant material transport is less well understood. The primary metric used in the calculations is the percent of drifters released within a region that cross the 100 m isobath. Results of the analysis indicate that, averaged over the eleven years of the simulation, there are two regions on the shelf - over the Texas shelf during winter, and over the Louisiana shelf in summer - with increased seasonal probability for offshore transport. Among the two other distinct regions, the big bend region in Texas has increased probability for onshore transport, and the Mississippi Delta region has an increase in offshore transport, for both seasons. Some of these regions of offshore transport have marked interannual variability. This interannual variability is correlated to interannual changes in forcing conditions. Winter transport off of the Texas shelf is correlated with winter mean wind direction, with more northerly winds enhancing offshore transport; summer transport off the Louisiana shelf is correlated with Mississippi River discharge.
Pancreatic enzyme replacement therapy for people with cystic fibrosis.

PubMed

Somaraju, Usha Rani; Solis-Moya, Arturo

2016-11-23

Most people with cystic fibrosis (80% to 90%) need pancreatic enzyme replacement therapy to prevent malnutrition. Enzyme preparations need to be taken whenever food is taken, and the dose needs to be adjusted according to the food consumed. A systematic review on the efficacy and safety of pancreatic enzyme replacement therapy is needed to guide clinical practice, as there is variability between centres with respect to assessment of pancreatic function, time of commencing treatment, dose and choice of supplements. This is an updated version of a published review. To evaluate the efficacy and safety of pancreatic enzyme replacement therapy in children and adults with cystic fibrosis and to compare the efficacy and safety of different formulations of this therapy and their appropriateness in different age groups. Also, to compare the effects of pancreatic enzyme replacement therapy in cystic fibrosis according to different diagnostic subgroups (e.g. different ages at introduction of therapy and different categories of pancreatic function). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search: 15 July 2016.We also searched an ongoing trials website and the websites of the pharmaceutical companies who manufacture pancreatic enzyme replacements for any additional trials. Most recent search: 22 July 2016. Randomised and quasi-randomised controlled trials in people of any age, with cystic fibrosis and receiving pancreatic enzyme replacement therapy, at any dosage and in any formulation, for a period of not less than four weeks, compared to placebo or other pancreatic enzyme replacement therapy preparations. Two authors independently assessed trials and extracted outcome data. They also assessed the risk of bias of the trials included in the review. One parallel trial and 12 cross-over trials of children and adults with cystic fibrosis were included in the review. The number of participants in each trial varied between 14 and 129 with a total of 512 participants included in the review. All the included trials were for a duration of four weeks. The included trials had mostly an unclear risk of bias from the randomisation process as the details of this were not given; they also mostly had a high risk of attrition bias and reporting bias.We could not combine data from all the trials as they compared different formulations. Findings from individual studies provided insufficient evidence to determine the size and precision of the effects of different formulations. Ten studies reported information on the review's primary outcome (nutritional status); however, we were only able to combine data from two small cross-over studies (n = 41). The estimated gain in body weight was imprecise, 0.32 kg (95% confidence interval -0.03 to 0.67; P = 0.07). Combined data from the same studies gave statistically significant results favouring enteric-coated microspheres over enteric-coated tablets for our secondary outcomes stool frequency, mean difference -0.58 (95% confidence interval -0.85 to -0.30; P < 0.0001); proportion of days with abdominal pain, mean difference -7.96% (95% confidence interval -12.97 to -2.94; P = 0.002); and fecal fat excretion, mean difference -11.79 g (95% confidence interval -17.42 to -6.15; P < 0.0001). Data from another single small cross-over study also favoured enteric-coated microspheres over non-enteric-coated tablets with adjuvant cimetidine in terms of stool frequency, mean difference -0.70 (95% confidence interval -0.90 to -0.50; P < 0.00001). There is limited evidence of benefit from enteric-coated microspheres when compared to non-enteric coated pancreatic enzyme preparations up to one month. In the only comparison where we could combine any data, the fact that these were cross-over studies is likely to underestimate the level of inconsistency between the results of the studies due to over-inflation of confidence intervals from the individual studies.There is no evidence on the long-term effectiveness and risks associated with pancreatic enzyme replacement therapy. There is also no evidence on the relative dosages of enzymes needed for people with different levels of severity of pancreatic insufficiency, optimum time to start treatment and variations based on differences in meals and meal sizes. There is a need for a properly designed study that can answer these questions.
Flexible chain molecules in the marginal and concentrated regimes: universal static scaling laws and cross-over predictions.

PubMed

Laso, Manuel; Karayiannis, Nikos Ch

2008-05-07

We present predictions for the static scaling exponents and for the cross-over polymer volumetric fractions in the marginal and concentrated solution regimes. Corrections for finite chain length are made. Predictions are based on an analysis of correlated fluctuations in density and chain length, in a semigrand ensemble in which mers and solvent sites exchange identities. Cross-over volumetric fractions are found to be chain length independent to first order, although reciprocal-N corrections are also estimated. Predicted scaling exponents and cross-over regimes are compared with available data from extensive off-lattice Monte Carlo simulations [Karayiannis and Laso, Phys. Rev. Lett. 100, 050602 (2008)] on freely jointed, hard-sphere chains of average lengths from N=12-500 and at packing densities from dilute ones up to the maximally random jammed state.
A cluster randomised controlled trial of a comprehensive accreditation intervention to reduce alcohol consumption at community sports clubs: study protocol

PubMed Central

Wolfenden, Luke; Rowland, Bosco C; Tindall, Jennifer; Gillham, Karen E; McElduff, Patrick; Rogerson, John C; Wiggers, John H

2011-01-01

Introduction Excessive alcohol consumption is responsible for considerable harm from chronic disease and injury. Within most developed countries, members of sporting clubs consume alcohol at levels above that of communities generally. Despite the potential benefits of interventions to address alcohol consumption in sporting clubs, there have been no randomised controlled trials to test the effectiveness of these interventions. The aim of this study is to examine the effectiveness of a comprehensive accreditation intervention with community football clubs (Rugby League, Rugby Union, soccer/association football and Australian Rules football) in reducing excessive alcohol consumption by club members. Methods and analysis The study will be conducted in New South Wales, Australia, and employ a cluster randomised controlled trial design. Half of the football clubs recruited to the trial will be randomised to receive an intervention implemented over two and a half winter sporting seasons. The intervention is based on social ecology theory and is comprehensive in nature, containing multiple elements designed to decrease the supply of alcohol to intoxicated members, cease the provision of cheap and free alcohol, increase the availability and cost-attractiveness of non-alcoholic and low-alcoholic beverages, remove high alcohol drinks and cease drinking games. The intervention utilises a three-tiered accreditation framework designed to motivate intervention implementation. Football clubs in the control group will receive printed materials on topics unrelated to alcohol. Outcome data will be collected pre- and postintervention through cross-sectional telephone surveys of club members. The primary outcome measure will be alcohol consumption by club members at the club, assessed using a graduated frequency index and a seven day diary. Ethics and dissemination The study was approved by The University of Newcastle Human Research Ethics Committee (reference: H-2008-0432). Study findings will be disseminated widely through peer-reviewed publications and conference presentations. Trial registration number Australian New Zealand Clinical Trials Registry: ACTRN12609000224224. PMID:22021867
A simple randomisation procedure for validating discriminant analysis: a methodological note.

PubMed

Wastell, D G

1987-04-01

Because the goal of discriminant analysis (DA) is to optimise classification, it designedly exaggerates between-group differences. This bias complicates validation of DA. Jack-knifing has been used for validation but is inappropriate when stepwise selection (SWDA) is employed. A simple randomisation test is presented which is shown to give correct decisions for SWDA. The general superiority of randomisation tests over orthodox significance tests is discussed. Current work on non-parametric methods of estimating the error rates of prediction rules is briefly reviewed.
Rehabilitation of divided attention after severe traumatic brain injury: a randomised trial.

PubMed

Couillet, Josette; Soury, Stephane; Lebornec, Gaelle; Asloun, Sybille; Joseph, Pierre-Alain; Mazaux, Jean-Michel; Azouvi, Philippe

2010-06-01

Patients with severe traumatic brain injury (TBI) frequently suffer from a difficulty in dealing with two tasks simultaneously. However, there has been little research on the rehabilitation of divided attention. The objective of the present study was to assess the effectiveness of a rehabilitation programme for divided attention after severe TBI. Twelve patients at a subacute/chronic stage after a severe TBI were included. A randomised AB vs. BA cross-over design was used. Training lasted six weeks, with four one-hour sessions per week. It was compared to a non-specific (control) cognitive training. During experimental treatment, patients were trained to perform two concurrent tasks simultaneously. Each one of the two tasks was first trained as a single task, then both tasks were given simultaneously. A progressive hierarchical order of difficulty was used, by progressively increasing task difficulty following each patient's individual improvement. Patients were randomised in two groups: one starting with dual-task training, the other with control training. Outcome measures included target dual-task measures, executive and working memory tasks, non-target tasks, and the Rating Scale of Attentional Behaviour addressing attentional problems in everyday life. Assessment was not blind to treatment condition. A significant training-related effect was found on dual-task measures and on the divided attention item of the Rating Scale of Attentional Behaviour. There was only little effect on executive measures, and no significant effect on non-target measures. These results suggest that training had specific effects on divided attention and helped patients to deal more rapidly and more accurately with dual-task situations.
[3D Virtual Reality Laparoscopic Simulation in Surgical Education - Results of a Pilot Study].

PubMed

Kneist, W; Huber, T; Paschold, M; Lang, H

2016-06-01

The use of three-dimensional imaging in laparoscopy is a growing issue and has led to 3D systems in laparoscopic simulation. Studies on box trainers have shown differing results concerning the benefit of 3D imaging. There are currently no studies analysing 3D imaging in virtual reality laparoscopy (VRL). Five surgical fellows, 10 surgical residents and 29 undergraduate medical students performed abstract and procedural tasks on a VRL simulator using conventional 2D and 3D imaging in a randomised order. No significant differences between the two imaging systems were shown for students or medical professionals. Participants who preferred three-dimensional imaging showed significantly better results in 2D as wells as in 3D imaging. First results on three-dimensional imaging on box trainers showed different results. Some studies resulted in an advantage of 3D imaging for laparoscopic novices. This study did not confirm the superiority of 3D imaging over conventional 2D imaging in a VRL simulator. In the present study on 3D imaging on a VRL simulator there was no significant advantage for 3D imaging compared to conventional 2D imaging. Georg Thieme Verlag KG Stuttgart · New York.
Competitor presence reduces internal attentional focus and improves 16.1km cycling time trial performance.

PubMed

Williams, Emily L; Jones, Hollie S; Andy Sparks, S; Marchant, David C; Midgley, Adrian W; Mc Naughton, Lars R

2015-07-01

Whilst the presence of a competitor has been found to improve performance, the mechanisms influencing the change in selected work rates during direct competition have been suggested but not specifically assessed. The aim was to investigate the physiological and psychological influences of a visual avatar competitor during a 16.1-km cycling time trial performance, using trained, competitive cyclists. Randomised cross-over design. Fifteen male cyclists completed four 16.1km cycling time trials on a cycle ergometer, performing two with a visual display of themselves as a simulated avatar (FAM and SELF), one with no visual display (DO), and one with themselves and an opponent as simulated avatars (COMP). Participants were informed the competitive avatar was a similar ability cyclist but it was actually a representation of their fastest previous performance. Increased performance times were evident during COMP (27.8±2.0min) compared to SELF (28.7±1.9min) and DO (28.4±2.3min). Greater power output, speed and heart rate were apparent during COMP trial than SELF (p<0.05) and DO (p≤0.06). There were no differences between SELF and DO. Ratings of perceived exertion were unchanged across all conditions. Internal attentional focus was significantly reduced during COMP trial (p<0.05), suggesting reduced focused on internal sensations during an increase in performance. Competitive cyclists performed significantly faster during a 16.1-km competitive trial than when performing maximally, without a competitor. The improvement in performance was elicited due to a greater external distraction, deterring perceived exertion. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The impact of manual defibrillation technique on no-flow time during simulated cardiopulmonary resuscitation.

PubMed

Perkins, Gavin D; Davies, Robin P; Soar, Jasmeet; Thickett, David R

2007-04-01

Rapid defibrillation is the most effective strategy for establishing return of spontaneous circulation following cardiac arrest due to ventricular fibrillation. The aim of this study is to measure the delay due to of charging the defibrillator during chest compression in an attempt to reduce the duration of the pre-shock pause in between cessation of chest compressions and shock delivery as advocated by the American Heart Association (AHA) guidelines compared to charging the defibrillator immediately following rhythm analysis without resuming chest compressions as recommended by the European Resuscitation Council (ERC). This was a randomised controlled cross over trial comparing pre-shock pause times when defibrillation was performed on a manikin according to the AHA and ERC guidelines using paddles and hands free defibrillation systems. The pre-shock pause between cessation of chest compression and shock delivery was significantly different between techniques (Friedman test, P<0.0001). ERC paddles technique had the greatest pre-shock pause (7.4 s [6.7-11.2]) followed by ERC hands free (7.0 s [6.5-8.5]) and AHA paddles (1.6 s [1.1-2.3]). AHA hands free took the least amount of time (1.5 s [0.8-1.5]). Extrapolating these data to older defibrillators with longer charge times saw pre-shock pause intervals of 9 s (Codemaster XL) and 12 s (Lifepak 20) with the ERC approach. This study demonstrated clinically significant delays to defibrillation by analysing and charging the defibrillator without performing concurrent chest compressions. In a simulated scenario, charging the defibrillator whilst performing chest compressions was perceived as safe and significantly reduced the pre-shock pause between cessation of chest compression and shock delivery.
Using virtual reality to train children in safe street-crossing skills.

PubMed

Schwebel, David C; McClure, Leslie A

2010-02-01

Pedestrian injuries are among the leading causes of morbidity and mortality in middle childhood. One limitation to existing pedestrian safety interventions is that they do not provide children with repeated practice needed to develop the complex perceptual and cognitive skills required for safe street crossing. Virtual reality offers training through repeated unsupervised practice without risk, automated feedback on success of crossings, adjustment of traffic to match children's skill and a fun, appealing environment for training. To test the efficacy of virtual reality to train child pedestrians in safe street crossing. Birmingham, Alabama, USA. A randomised controlled trial is underway with an expected sample of four groups of 60 children aged 7-8 years (total N=240). One group receives training in an interactive, immersive virtual pedestrian environment. A second receives pedestrian safety training via widely used video and computer strategies. The third group receives what is judged to be the most efficacious treatment currently available, individualised behavioural training at streetside locations. The fourth group serves as a no-contact control group. All participants are exposed to a range of field and laboratory-based measures of pedestrian skill during baseline and post-intervention visits, as well as during a 6-month follow-up assessment. Primary analyses will be conducted through linear mixed models testing change over time in the four intervention groups. Three pedestrian safety measures will serve as primary outcomes: temporal gap before initiating crossing, temporal gap remaining after crossing and attention to traffic while waiting to cross.
The scatter of research: cross sectional comparison of randomised trials and systematic reviews across specialties

PubMed Central

Erueti, Chrissy; Thorning, Sarah; Glasziou, Paul

2012-01-01

Objective To estimate the degree of scatter of reports of randomised trials and systematic reviews, and how the scatter differs among medical specialties and subspecialties. Design Cross sectional analysis. Data source PubMed for all disease relevant randomised trials and systematic reviews published in 2009. Study selection Randomised trials and systematic reviews of the nine diseases or disorders with the highest burden of disease, and the broader category of disease to which each belonged. Results The scatter across journals varied considerably among specialties and subspecialties: otolaryngology had the least scatter (363 trials across 167 journals) and neurology the most (2770 trials across 896 journals). In only three subspecialties (lung cancer, chronic obstructive pulmonary disease, hearing loss) were 10 or fewer journals needed to locate 50% of trials. The scatter was less for systematic reviews: hearing loss had the least scatter (10 reviews across nine journals) and cancer the most (670 reviews across 279 journals). For some specialties and subspecialties the papers were concentrated in specialty journals; whereas for others, few of the top 10 journals were a specialty journal for that area. Generally, little overlap occurred between the top 10 journals publishing trials and those publishing systematic reviews. The number of journals required to find all trials or reviews was highly correlated (r=0.97) with the number of papers for each specialty/subspecialty. Conclusions Publication rates of speciality relevant trials vary widely, from one to seven trials per day, and are scattered across hundreds of general and specialty journals. Although systematic reviews reduce the extent of scatter, they are still widely scattered and mostly in different journals to those of randomised trials. Personal subscriptions to journals, which are insufficient for keeping up to date with knowledge, need to be supplemented by other methods such as journal scanning services or systems that cover sufficient journals and filter articles for quality and relevance. Few current systems seem adequate. PMID:22597353
Exercise response in Parkinson’s disease: insights from a cross-sectional comparison with sedentary controls and a per-protocol analysis of a randomised controlled trial

PubMed Central

Collett, Johnny; Franssen, Marloes; Meaney, Andy; Sexton, Claire; Dennis-West, Andrea; Betts, Jill F; Izadi, Hooshang; Bogdanovic, Marko; Tims, Martin; Farmer, Andrew; Dawes, Helen

2017-01-01

Objectives To investigate the acute and adaptation cardiovascular and metabolic training responses in people with Parkinson’s disease (pwP). Design (1) A cross-sectional study of exercise response of pwP compared with sedentary controls and (2) an interventional study of exercise training in pwP. Setting Community leisure facilities. Participants pwP (n=83) and sedentary controls (n=55). Interventions Study 1 included participants from a two-arm-parallel single-blind phase II randomised controlled trial (RCT), that undertook a baseline maximal incremental exercise test and study 2 included those randomised to the exercise group in the RCT, who completed a 6-month weekly exercise programme (n=37). The intervention study 2 was a prescribed exercise program consisting of sessions lasting 60 min, two times a week over a 6-month period. The control group followed the same protocol which derived the same cardiorespiratory parameters, except that they were instructed to aim for a cadence of ~60 revolutions per minute and the unloaded phase lasted 3 min with an initial step of 25 W. Primary and secondary outcome measures Stepwise incremental exercise test to volitional exhaustion was the primary outcome measure. Results Study 1 showed higher maximum values for heart rate (HR), VO2 L/min, VCO2 L/min and ventilation L/min for the control group; respiratory exchange ratio (RER), perceived exertion and O2 pulse (VO2 L/min/HR) did not differ between groups. In study 2, for pwP who adhered to training (n=37), RER increased significantly and although there was no significant change in aerobic capacity or HR response, reduced blood pressure was found. Conclusions An abnormal cardiovascular response to exercise was observed in pwP compared to controls. After the exercise programme, metabolic deficiencies remained for pwP. These observations add to the pathogenic understanding of PD, acknowledge an underling metabolic contribution and support that certain cardiovascular symptoms may improve as a result of this type of exercise. PMID:29282259
A randomised controlled trial of extended immersion in multi-method continuing simulation to prepare senior medical students for practice as junior doctors

PubMed Central

2014-01-01

Background Many commencing junior doctors worldwide feel ill-prepared to deal with their new responsibilities, particularly prescribing. Simulation has been widely utilised in medical education, but the use of extended multi-method simulation to emulate the junior doctor experience has rarely been reported. Methods A randomised controlled trial compared students who underwent two, week-long, extended simulations, several months apart (Intervention), with students who attended related workshops and seminars alone (Control), for a range of outcome measures. Results Eighty-four third year students in a graduate-entry medical program were randomised, and 82 completed the study. At the end of the first week, Intervention students scored a mean of 75% on a prescribing test, compared with 70% for Control students (P = 0.02) and Intervention teams initiated cardiac compressions a mean of 29.1 seconds into a resuscitation test scenario, compared with 70.1 seconds for Control teams (P < 0.01). At the beginning of the second week, an average of nine months later, a significant difference was maintained in relation to the prescribing test only (78% vs 70%, P < 0.01). At the end of the second week, significant Intervention vs Control differences were seen on knowledge and reasoning tests, a further prescribing test (71% vs 63% [P < 0.01]) and a paediatric resuscitation scenario test (252 seconds to initiation of fluid resuscitation vs 339 seconds [P = 0.05]). Conclusions The study demonstrated long-term retention of improved prescribing skills, and an immediate effect on knowledge acquisition, reasoning and resuscitation skills, from contextualising learning activities through extended multi-method simulation. PMID:24886098
Continuous versus bolus intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease.

PubMed

Richards, Robyn; Foster, Jann P; Psaila, Kim

2014-07-17

Gastro-oesophageal reflux disease is a particularly common condition in preterm and low birth weight infants. These infants are also more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus or continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease. To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants.We intended to perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast vs bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication prescribed and given similarly to both intervention groups). We used the standard search strategy of the Cochrane Neonatal Group as described in The Cochrane Library (www.thecochranelibrary.com) to search for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 9), MEDLINE (1966 to September 2013), EMBASE (1980 to September 2013) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to September 2013). We also searched previous reviews, including cross-references, abstracts and conference and symposia proceedings of the Perinatal Society of Australia and New Zealand and the Pediatric Academic Societies (American Pediatric Society/Society for Pediatric Research and European Society for Paediatric Research) from 1990 to 2012. Published and unpublished RCTs and quasi-RCTs were eligible for inclusion in this review, as were cluster-randomised and cross-over randomised trials that compared the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Two review authors independently assessed study eligibility and quality. We found no trials that met the inclusion criteria for this review. We did not identify any randomised trials that evaluated the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Well-designed and adequately powered trials are needed.
Effect of fibre additions to flatbread flour mixes on glucose kinetics: a randomised controlled trial.

PubMed

Boers, Hanny M; van Dijk, Theo H; Hiemstra, Harry; Hoogenraad, Anne-Roos; Mela, David J; Peters, Harry P F; Vonk, Roel J; Priebe, Marion G

2017-11-01

We previously found that guar gum (GG) and chickpea flour (CPF) added to flatbread wheat flour lowered postprandial blood glucose (PPG) and insulin responses dose dependently. However, rates of glucose influx cannot be determined from PPG, which integrates rates of influx, tissue disposal and hepatic glucose production. The objective was to quantify rates of glucose influx and related fluxes as contributors to changes in PPG with GG and CPF additions to wheat-based flatbreads. In a randomised cross-over design, twelve healthy males consumed each of three different 13C-enriched meals: control flatbreads (C), or C incorporating 15 % CPF with either 2 % (GG2) or 4 % (GG4) GG. A dual isotope technique was used to determine the time to reach 50 % absorption of exogenous glucose (T 50 %abs, primary objective), rate of appearance of exogenous glucose (RaE), rate of appearance of total glucose (RaT), endogenous glucose production (EGP) and rate of disappearance of total glucose (RdT). Additional exploratory outcomes included PPG, insulin, glucose-dependent insulinotropic peptide and glucagon-like peptide 1, which were additionally measured over 4 h. Compared with C, GG2 and GG4 had no significant effect on T 50 %abs. However, GG4 significantly reduced 4-h AUC values for RaE, RaT, RdT and EGP, by 11, 14, 14 and 64 %, respectively, whereas GG2 showed minor effects. Effect sizes over 2 and 4 h were similar except for significantly greater reduction in EGP for GG4 at 2 h. In conclusion, a soluble fibre mix added to flatbreads only slightly reduced rates of glucose influx, but more substantially affected rates of postprandial disposal and hepatic glucose production.
Evaluation of In Vitro Cross-Reactivity to Avian H5N1 and Pandemic H1N1 2009 Influenza Following Prime Boost Regimens of Seasonal Influenza Vaccination in Healthy Human Subjects: A Randomised Trial

DTIC Science & Technology

2013-03-26

virus (IIV) vaccine (dose 0.5 mL intramuscularly, purchased in Thailand from Sanofi Pasteur). Both vaccines contained the three strains for the 2009/10...H1N1 2009 Influenza Following Prime Boost Regimens of Seasonal Influenza Vaccination in Healthy Human Subjects: A Randomised Trial. 5a. CONTRACT NUMBER...reported by WHO since 2003 [1]. Current seasonal trivalent influenza vaccines rely on predicted antigens based on the previous season’s circulating
Randomised trials in context: practical problems and social aspects of evidence-based medicine and policy.

PubMed

Pearce, Warren; Raman, Sujatha; Turner, Andrew

2015-09-01

Randomised trials can provide excellent evidence of treatment benefit in medicine. Over the last 50 years, they have been cemented in the regulatory requirements for the approval of new treatments. Randomised trials make up a large and seemingly high-quality proportion of the medical evidence-base. However, it has also been acknowledged that a distorted evidence-base places a severe limitation on the practice of evidence-based medicine (EBM). We describe four important ways in which the evidence from randomised trials is limited or partial: the problem of applying results, the problem of bias in the conduct of randomised trials, the problem of conducting the wrong trials and the problem of conducting the right trials the wrong way. These problems are not intrinsic to the method of randomised trials or the EBM philosophy of evidence; nevertheless, they are genuine problems that undermine the evidence that randomised trials provide for decision-making and therefore undermine EBM in practice. Finally, we discuss the social dimensions of these problems and how they highlight the indispensable role of judgement when generating and using evidence for medicine. This is the paradox of randomised trial evidence: the trials open up expert judgment to scrutiny, but this scrutiny in turn requires further expertise.
Virtual reality simulator training of laparoscopic cholecystectomies - a systematic review.

PubMed

Ikonen, T S; Antikainen, T; Silvennoinen, M; Isojärvi, J; Mäkinen, E; Scheinin, T M

2012-01-01

Simulators are widely used in occupations where practice in authentic environments would involve high human or economic risks. Surgical procedures can be simulated by increasingly complex and expensive techniques. This review gives an update on computer-based virtual reality (VR) simulators in training for laparoscopic cholecystectomies. From leading databases (Medline, Cochrane, Embase), randomised or controlled trials and the latest systematic reviews were systematically searched and reviewed. Twelve randomised trials involving simulators were identified and analysed, as well as four controlled studies. Furthermore, seven studies comparing black boxes and simulators were included. The results indicated any kind of simulator training (black box, VR) to be beneficial at novice level. After VR training, novice surgeons seemed to be able to perform their first live cholecystectomies with fewer errors, and in one trial the positive effect remained during the first ten cholecystectomies. No clinical follow-up data were found. Optimal learning requires skills training to be conducted as part of a systematic training program. No data on the cost-benefit of simulators were found, the price of a VR simulator begins at EUR 60 000. Theoretical background to learning and limited research data support the use of simulators in the early phases of surgical training. The cost of buying and using simulators is justified if the risk of injuries and complications to patients can be reduced. Developing surgical skills requires repeated training. In order to achieve optimal learning a validated training program is needed.
Dissociation cross section for high energy O2-O2 collisions

NASA Astrophysics Data System (ADS)

Mankodi, T. K.; Bhandarkar, U. V.; Puranik, B. P.

2018-04-01

Collision-induced dissociation cross section database for high energy O2-O2 collisions (up to 30 eV) is generated and published using the quasiclassical trajectory method on the singlet, triplet, and quintet spin ground state O4 potential energy surfaces. At equilibrium conditions, these cross sections predict reaction rate coefficients that match those obtained experimentally. The main advantage of the cross section database based on ab initio computations is in the study of complex flows with high degree of non-equilibrium. Direct simulation Monte Carlo simulations using the reactive cross section databases are carried out for high enthalpy hypersonic oxygen flow over a cylinder at rarefied ambient conditions. A comparative study with the phenomenological total collision energy chemical model is also undertaken to point out the difference and advantage of the reported ab initio reaction model.
Multiple imputation methods for bivariate outcomes in cluster randomised trials.

PubMed

DiazOrdaz, K; Kenward, M G; Gomes, M; Grieve, R

2016-09-10

Missing observations are common in cluster randomised trials. The problem is exacerbated when modelling bivariate outcomes jointly, as the proportion of complete cases is often considerably smaller than the proportion having either of the outcomes fully observed. Approaches taken to handling such missing data include the following: complete case analysis, single-level multiple imputation that ignores the clustering, multiple imputation with a fixed effect for each cluster and multilevel multiple imputation. We contrasted the alternative approaches to handling missing data in a cost-effectiveness analysis that uses data from a cluster randomised trial to evaluate an exercise intervention for care home residents. We then conducted a simulation study to assess the performance of these approaches on bivariate continuous outcomes, in terms of confidence interval coverage and empirical bias in the estimated treatment effects. Missing-at-random clustered data scenarios were simulated following a full-factorial design. Across all the missing data mechanisms considered, the multiple imputation methods provided estimators with negligible bias, while complete case analysis resulted in biased treatment effect estimates in scenarios where the randomised treatment arm was associated with missingness. Confidence interval coverage was generally in excess of nominal levels (up to 99.8%) following fixed-effects multiple imputation and too low following single-level multiple imputation. Multilevel multiple imputation led to coverage levels of approximately 95% throughout. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.
Simulation in Occupational Therapy Curricula: A literature review.

PubMed

Bennett, Sally; Rodger, Sylvia; Fitzgerald, Cate; Gibson, Libby

2017-08-01

Simulated learning experiences are increasingly being used in health-care education to enhance student engagement and provide experiences that reflect clinical practice; however, simulation has not been widely investigated in occupational therapy curricula. The aim of this paper was to: (i) describe the existing research about the use and evaluation of simulation over the last three decades in occupational therapy curricula and (ii) consider how simulation has been used to develop competence in students. A literature review was undertaken with searches of MEDLINE, CINAHL and ERIC to locate articles that described or evaluated the use of simulation in occupational therapy curricula. Fifty-seven papers were identified. Occupational therapy educators have used the full scope of simulation modalities, including written case studies (22), standardised patients (13), video case studies (15), computer-based and virtual reality cases (7), role-play (8) and mannequins and part-task trainers (4). Ten studies used combinations of these modalities and two papers compared modalities. Most papers described the use of simulation for foundational courses, as for preparation for fieldwork, and to address competencies necessary for newly graduating therapists. The majority of studies were descriptive, used pre-post design, or were student's perceptions of the value of simulation. Simulation-based education has been used for a wide range of purposes in occupational therapy curricula and appears to be well received. Randomised controlled trials are needed to more accurately understand the effects of simulation not just for occupational therapy students but for longer term outcomes in clinical practice. © 2017 Occupational Therapy Australia.
Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial.

PubMed

Sørensen, Jette Led; van der Vleuten, Cees; Rosthøj, Susanne; Østergaard, Doris; LeBlanc, Vicki; Johansen, Marianne; Ekelund, Kim; Starkopf, Liis; Lindschou, Jane; Gluud, Christian; Weikop, Pia; Ottesen, Bent

2015-10-06

To investigate the effect of in situ simulation (ISS) versus off-site simulation (OSS) on knowledge, patient safety attitude, stress, motivation, perceptions of simulation, team performance and organisational impact. Investigator-initiated single-centre randomised superiority educational trial. Obstetrics and anaesthesiology departments, Rigshospitalet, University of Copenhagen, Denmark. 100 participants in teams of 10, comprising midwives, specialised midwives, auxiliary nurses, nurse anaesthetists, operating theatre nurses, and consultant doctors and trainees in obstetrics and anaesthesiology. Two multiprofessional simulations (clinical management of an emergency caesarean section and a postpartum haemorrhage scenario) were conducted in teams of 10 in the ISS versus the OSS setting. Knowledge assessed by a multiple choice question test. Individual outcomes: scores on the Safety Attitudes Questionnaire, stress measurements (State-Trait Anxiety Inventory, cognitive appraisal and salivary cortisol), Intrinsic Motivation Inventory and perceptions of simulations. Team outcome: video assessment of team performance. Organisational impact: suggestions for organisational changes. The trial was conducted from April to June 2013. No differences between the two groups were found for the multiple choice question test, patient safety attitude, stress measurements, motivation or the evaluation of the simulations. The participants in the ISS group scored the authenticity of the simulation significantly higher than did the participants in the OSS group. Expert video assessment of team performance showed no differences between the ISS versus the OSS group. The ISS group provided more ideas and suggestions for changes at the organisational level. In this randomised trial, no significant differences were found regarding knowledge, patient safety attitude, motivation or stress measurements when comparing ISS versus OSS. Although participant perception of the authenticity of ISS versus OSS differed significantly, there were no differences in other outcomes between the groups except that the ISS group generated more suggestions for organisational changes. NCT01792674. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Run charts revisited: a simulation study of run chart rules for detection of non-random variation in health care processes.

PubMed

Anhøj, Jacob; Olesen, Anne Vingaard

2014-01-01

A run chart is a line graph of a measure plotted over time with the median as a horizontal line. The main purpose of the run chart is to identify process improvement or degradation, which may be detected by statistical tests for non-random patterns in the data sequence. We studied the sensitivity to shifts and linear drifts in simulated processes using the shift, crossings and trend rules for detecting non-random variation in run charts. The shift and crossings rules are effective in detecting shifts and drifts in process centre over time while keeping the false signal rate constant around 5% and independent of the number of data points in the chart. The trend rule is virtually useless for detection of linear drift over time, the purpose it was intended for.
Broadband high-efficiency half-wave plate: a supercell-based plasmonic metasurface approach.

PubMed

Ding, Fei; Wang, Zhuoxian; He, Sailing; Shalaev, Vladimir M; Kildishev, Alexander V

2015-04-28

We design, fabricate, and experimentally demonstrate an ultrathin, broadband half-wave plate in the near-infrared range using a plasmonic metasurface. The simulated results show that the linear polarization conversion efficiency is over 97% with over 90% reflectance across an 800 nm bandwidth. Moreover, simulated and experimental results indicate that such broadband and high-efficiency performance is also sustained over a wide range of incident angles. To further obtain a background-free half-wave plate, we arrange such a plate as a periodic array of integrated supercells made of several plasmonic antennas with high linear polarization conversion efficiency, consequently achieving a reflection-phase gradient for the cross-polarized beam. In this design, the anomalous (cross-polarized) and the normal (copolarized) reflected beams become spatially separated, hence enabling highly efficient and robust, background-free polarization conversion along with broadband operation. Our results provide strategies for creating compact, integrated, and high-performance plasmonic circuits and devices.
A randomised controlled intervention trial evaluating the efficacy of a Mediterranean dietary pattern on cognitive function and psychological wellbeing in healthy older adults: the MedLey study.

PubMed

Knight, Alissa; Bryan, Janet; Wilson, Carlene; Hodgson, Jonathan; Murphy, Karen

2015-04-28

The incidence of age-related cognitive decline is rising considerably around the world. There is evidence from a number of recent cross-sectional and prospective studies indicating positive associations between the Mediterranean dietary pattern (MedDiet) and improved cognitive outcomes among the elderly including, reduced age-related cognitive decline and enhanced age-related cognitive performance. However, to date no study has validated these associations in healthy older adult populations (≥65 years and above) with randomised evidence. The main aim of the present study is to provide justified evidence regarding the efficacy of a MedDiet approach to safely reduce the onset of cognitive decline, and promote optimal cognitive performance among healthy older adults using rigorous, randomised intervention methodology. MedLey is a 6-month, randomised controlled 2-cohort parallel group intervention trial, with initial assessment at baseline and repeated every three months. A sample of 166 healthy Australian men and women aged 65 years and above, with normal cognitive function and proficient in English language were recruited from metropolitan Adelaide, South Australia for the study. Participants randomly allocated to the experimental group are required to maintain an intervention dietary pattern based from the traditional Cretan MedDiet (i.e. vegetables, fruits, olive oil, legumes, fish, whole grain cereals, nuts and seeds and low consumption of processed foods, dairy products, red meat and vegetable oils) for six months, while those participants allocated to the control group are asked to maintain their customary lifestyle and diet. The primary outcome of interest is the quantitative difference in age-related cognitive performance, as measured by latent variables (cognitive constructs) sensitive to normal ageing and diet (i.e. speed of processing, memory, attention, executive functions, visual spatial and visuomotor ability). Secondary outcomes include change in biomarkers of inflammation, oxidative stress, lipid metabolism, glucose, insulin, blood flow velocity, and psychological well-being factors (i.e. stress, sleep, anxiety, depression). To our knowledge this will be one of the first randomised clinical trials worldwide to provide evidence for the cause-effect relationship between the MedDiet and age-related cognitive function in a healthy older adult population (≥65 years and over). Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12613000602729.
Ataluren in cystic fibrosis: development, clinical studies and where are we now?

PubMed

Zainal Abidin, Noreen; Haq, Iram J; Gardner, Aaron I; Brodlie, Malcolm

2017-09-01

Cystic fibrosis (CF) is one of the most common genetically-acquired life-limiting conditions worldwide. The underlying defect is dysfunction of the cystic fibrosis transmembrane-conductance regulator (CFTR) which leads to progressive lung disease and other multi-system effects. Around 10% of people with CF have a class I nonsense mutation that leads to production of shortened CFTR due to a premature termination codon (PTC). Areas covered: We discuss the discovery of the small-molecule drug ataluren, which in vitro has been shown to allow read-through of PTCs and facilitate synthesis of full-length protein. We review clinical studies that have been performed involving ataluren in CF. Early-phase short-term cross-over studies showed improvement in nasal potential difference. A follow-up phase III randomised controlled trial did not show a significant difference for the primary outcome of lung function, however a post-hoc analysis suggested possible benefit in patients not receiving tobramycin. A further randomised controlled trial in patients not receiving tobramycin has been reported as showing no benefit but has not yet been published in full peer-reviewed form. Expert opinion: A small-molecule approach to facilitate read-through of PTCs in nonsense mutations makes intuitive sense. However, at present there is no high-quality evidence of clinical efficacy for ataluren in people with CF.
Effect of alternating postures on cognitive performance for healthy people performing sedentary work.

PubMed

Schwartz, Bernhard; Kapellusch, Jay M; Schrempf, Andreas; Probst, Kathrin; Haller, Michael; Baca, Arnold

2018-06-01

Prolonged sitting is a risk factor for several diseases and the prevalence of worksite-based interventions such as sit-to-stand workstations is increasing. Although their impact on sedentary behaviour has been regularly investigated, the effect of working in alternating body postures on cognitive performance is unclear. To address this uncertainty, 45 students participated in a two-arm, randomised controlled cross-over trial under laboratory conditions. Subjects executed validated cognitive tests (working speed, reaction time, concentration performance) either in sitting or alternating working postures on two separate days (ClinicalTrials.gov Identifier: NCT02863731). MANOVA results showed no significant difference in cognitive performance between trials executed in alternating, standing or sitting postures. Perceived workload did not differ between sitting and alternating days. Repeated measures ANOVA revealed significant learning effects regarding concentration performance and working speed for both days. These results suggest that working posture did not affect cognitive performance in the short term. Practitioner Summary: Prior reports indicated health-related benefits based on alternated (sit/stand) body postures. Nevertheless, their effect on cognitive performance is unknown. This randomised controlled trial showed that working in alternating body postures did not influence reaction time, concentration performance, working speed or workload perception in the short term.
Comparison of non-invasive tear film stability measurement techniques.

PubMed

Wang, Michael Tm; Murphy, Paul J; Blades, Kenneth J; Craig, Jennifer P

2018-01-01

Measurement of tear film stability is commonly used to give an indication of tear film quality but a number of non-invasive techniques exists within the clinical setting. This study sought to compare three non-invasive tear film stability measurement techniques: instrument-mounted wide-field white light clinical interferometry, instrument-mounted keratoscopy and hand-held keratoscopy. Twenty-two subjects were recruited in a prospective, randomised, masked, cross-over study. Tear film break-up or thinning time was measured non-invasively by independent experienced examiners, with each of the three devices, in a randomised order, within an hour. Significant correlation was observed between instrument-mounted interferometric and keratoscopic measurements (p < 0.001) but not between the hand-held device and the instrument-mounted techniques (all p > 0.05). Tear film stability values obtained from the hand-held device were significantly shorter and demonstrated narrower spread than the other two instruments (all p < 0.05), while no significant differences were observed between the two instrument-mounted devices (all p > 0.05). Good clinical agreement exists between the instrument-mounted interferometric and keratoscopic measurements but not between the hand-held device and either of the instrument-mounted techniques. The results highlight the importance of specifying the instrument employed to record non-invasive tear film stability. © 2017 Optometry Australia.

Active versus passive humidification for self-ventilating tracheostomy and laryngectomy patients: a systematic review of the literature.

PubMed

Wong, C Y Y; Shakir, A A; Farboud, A; Whittet, H B

2016-12-01

To determine whether active or passive humidification methods are more effective in preventing pulmonary complications in self-ventilating neck breather patients. Systematic Review adhering to PRISMA guidance (checklist sourced from www.equator-network.org/). Review of current published relevant literature at a tertiary department of Otolaryngology and Head & Neck Surgery. We included all separate studies and comparison studies of active and passive humidification techniques in adult and paediatric neck breather patients. The primary outcome is the reduction in pulmonary complications. Secondary outcomes include patient compliance; carer and user satisfaction. Seven studies were included in this review: two RCTs (133 patients), one randomised controlled cross-over trial (29 patients), three randomised prospective studies (171 patients), and one retrospective study (73 patients). Only one study was conducted on paediatric neck breathers. The overall quality of the studies was low. Five studies were at a high risk of bias. Of the remaining two studies, one study had a low risk of bias and the other had an unclear risk. Despite limited subject evidence, results show that passive methods of humidification (mainly HME) is the preferred choice of humidification in the spontaneously breathing neck breather patients group mainly due to the reduction in pulmonary complaints, and better patient compliance. © 2015 John Wiley & Sons Ltd.
Including pork in the Mediterranean diet for an Australian population: Protocol for a randomised controlled trial assessing cardiovascular risk and cognitive function.

PubMed

Wade, Alexandra T; Davis, Courtney R; Dyer, Kathryn A; Hodgson, Jonathan M; Woodman, Richard J; Keage, Hannah A D; Murphy, Karen J

2017-12-22

The Mediterranean diet is characterised by the high consumption of extra virgin olive oil, fruits, vegetables, grains, legumes and nuts; moderate consumption of fish, poultry, eggs and dairy; and low consumption of red meat and sweets. Cross sectional, longitudinal and intervention studies indicate that a Mediterranean diet may be effective for the prevention of cardiovascular disease and dementia. However, previous research suggests that an Australian population may find red meat restrictions difficult, which could affect long term sustainability of the diet. This paper outlines the protocol for a randomised controlled trial that will assess the cardiovascular and cognitive benefits of a Mediterranean diet modified to include 2-3 weekly serves of fresh, lean pork. A 24-week cross-over design trial will compare a modified Mediterranean diet with a low-fat control diet in at-risk men and women. Participants will follow each of the two diets for 8 weeks, with an 8-week washout period separating interventions. Home measured systolic blood pressure will be the primary outcome measure. Secondary outcomes will include body mass index, body composition, fasting blood lipids, C-reactive protein, fasting plasma glucose, fasting serum insulin, erythrocyte fatty acids, cognitive function, psychological health and well-being, and dementia risk. To our knowledge this research is the first to investigate whether an alternate source of protein can be included in the Mediterranean diet to increase sustainability and feasibility for a non-Mediterranean population. Findings will be significant for the prevention of cardiovascular disease and age-related decline, and may inform individuals, clinicians and public health policy. ACTRN12616001046493 . Registered 5 August 2016.
A shared-care model of obesity treatment for 3-10 year old children: protocol for the HopSCOTCH randomised controlled trial.

PubMed

Wake, Melissa; Lycett, Kate; Sabin, Matthew A; Gunn, Jane; Gibbons, Kay; Hutton, Cathy; McCallum, Zoe; York, Elissa; Stringer, Michael; Wittert, Gary

2012-03-28

Despite record rates of childhood obesity, effective evidence-based treatments remain elusive. While prolonged tertiary specialist clinical input has some individual impact, these services are only available to very few children. Effective treatments that are easily accessible for all overweight and obese children in the community are urgently required. General practitioners are logical care providers for obese children but high-quality trials indicate that, even with substantial training and support, general practitioner care alone will not suffice to improve body mass index (BMI) trajectories. HopSCOTCH (the Shared Care Obesity Trial in Children) will determine whether a shared-care model, in which paediatric obesity specialists co-manage obesity with general practitioners, can improve adiposity in obese children. Randomised controlled trial nested within a cross-sectional BMI survey conducted across 22 general practices in Melbourne, Australia. Children aged 3-10 years identified as obese by Centers for Disease Control criteria at their family practice, and randomised to either a shared-care intervention or usual care. A single multidisciplinary obesity clinic appointment at Melbourne's Royal Children's Hospital, followed by regular appointments with the child's general practitioner over a 12 month period. To support both specialist and general practice consultations, web-based shared-care software was developed to record assessment, set goals and actions, provide information to caregivers, facilitate communication between the two professional groups, and jointly track progress. Primary - change in BMI z-score. Secondary - change in percentage fat and waist circumference; health status, body satisfaction and global self-worth. This will be the first efficacy trial of a general-practitioner based, shared-care model of childhood obesity management. If effective, it could greatly improve access to care for obese children. Australian New Zealand Clinical Trials Registry ACTRN12608000055303.
Evaluation of eLearning for the teaching of undergraduate ophthalmology at medical school: a randomised controlled crossover study.

PubMed

Petrarca, Caroline A; Warner, Julia; Simpson, Andrew; Petrarca, Robert; Douiri, Abdel; Byrne, David; Jackson, Timothy L

2018-05-25

To compare ophthalmology teaching delivered by eLearning with traditional lectures, in terms of undergraduate performance and satisfaction. Randomised controlled crossover study at King's College London Medical School with 245 third year medical students. The ophthalmology syllabus was divided into ten topics. Five topics were randomised to be taught by traditional lectures and five by electronic learning (eLearning). For the second rotation of students the topics were crossed over, so that those topics taught by traditional lectures were taught by eLearning and vice versa. At the end of each rotation the students sat an optional online mock examination containing 100 questions (ten on each topic). Students' examination performance was compared between the two teaching methods. Student satisfaction was assessed using an online satisfaction survey. Outcome measures were the mean percentage of correct answers across all ten topics, student satisfaction and self-assessed knowledge. The mean examination score for questions taught by eLearning was 58% (95% CI, 55.7-59.6), versus 55% (95% CI 53.1-56.8) for traditional lectures (P = 0.047). Across all topics students were more satisfied with eLearning than traditional lectures, with 87% (95% CI 84.5-88.4) rating eLearning as 'excellent' or 'good' versus 65% (95% CI 62.0-67.4) for lectures (p < 0.0001). Overall 180 (75.6%) preferred eLearning compared to traditional lectures, with 166 (69.7%) rating eLearning 'much better' or 'better,' 61 (25.6%) 'neutral' and 11 (4.6%) 'worse' or 'much worse.' Student satisfaction and examination performance are both enhanced by ophthalmology eLearning. Similar eLearning modules may be suitable for other specialties and postgraduate learning.
Electron transport in furfural: dependence of the electron ranges on the cross sections and the energy loss distribution functions

NASA Astrophysics Data System (ADS)

Ellis-Gibbings, L.; Krupa, K.; Colmenares, R.; Blanco, F.; Muńoz, A.; Mendes, M.; Ferreira da Silva, F.; Limá Vieira, P.; Jones, D. B.; Brunger, M. J.; García, G.

2016-09-01

Recent theoretical and experimental studies have provided a complete set of differential and integral electron scattering cross section data from furfural over a broad energy range. The energy loss distribution functions have been determined in this study by averaging electron energy loss spectra for different incident energies and scattering angles. All these data have been used as input parameters for an event by event Monte Carlo simulation procedure to obtain the electron energy deposition patterns and electron ranges in liquid furfural. The dependence of these results on the input cross sections is then analysed to determine the uncertainty of the simulated values.
Vaccine testing for emerging infections: the case for individual randomisation

PubMed Central

Eyal, Nir; Lipsitch, Marc

2017-01-01

During the 2014–2015 Ebola outbreak in Guinea, Liberia and Sierra Leone, many opposed the use of individually randomised controlled trials to test candidate Ebola vaccines. For a raging fatal disease, they explained, it is unethical to relegate some study participants to control arms. In Zika and future emerging infections, similar opposition may hinder urgent vaccine research, so it is best to address these questions now. This article lays out the ethical case for individually randomised control in testing vaccines against many emerging infections, including lethal infections in low-income countries, even when at no point in the trial do the controls receive the countermeasures being tested. When individual randomisation is feasible—and it often will be—it tends to save more lives than alternative designs would. And for emerging infections, individual randomisation also tends as such to improve care, access to the experimental vaccine and prospects for all participants relative to their opportunities absent the trial, and no less than alternative designs would. That obtains even under placebo control and without equipoise—requiring which would undermine individual randomisation and the alternative designs that opponents proffered. Our arguments expound four often-neglected factors: benefits to non-participants, benefits to participants once a trial is over including post-trial access to the study intervention, participants’ prospects before randomisation to arms and the near-inevitable disparity between arms in any randomised controlled trial. PMID:28396558
Advantages of using voiced questionnaire and image capture application for data collection from a minority group in rural areas along the Thailand-Myanmar border.

PubMed

Monyarit, Siriporn; Pan-ngum, Wirichada; Lawpoolsri, Saranath; Yimsamran, Surapon; Pongnumkul, Suporn; Kaewkungwal, Jaranit; Singhasivanon, Pratap

2014-01-01

To compare the quality of data collection via electronic data capture (EDC) with voiced questionnaire (QNN) and data image capture features using a tablet versus standard paper-based QNN, to assess the user's perception of using the EDC tool, and to compare user satisfaction with the two methods. Randomised cross-over study. Study sites: This study was conducted in two villages along the Thailand-Myanmar border. This study included 30 community health volunteers (CHVs) and 120 Karen hill tribe villagers. Employing a cross-over study design, the CHVs were allocated randomly to two groups, in which they performed interviews in different sequences using EDC and QNN. Data discrepancies were found between the two data-collection methods, when data from the paper-based and image-capture methods were compared, and when conducting skip pattern questions. More than 90% of the CHVs perceived the EDC to be useful and easy to use. Both interviewers and interviewees were more satisfied with the EDC compared with QNN in terms of format, ease of use, and system speed. The EDC can effectively be used as an alternative method to paper-based QNNs for data collection. It produces more accurate data that can be considered evidence-based.
Sinonasal inhalation of dornase alfa administered by vibrating aerosol to cystic fibrosis patients: a double-blind placebo-controlled cross-over trial.

PubMed

Mainz, Jochen G; Schien, Claudia; Schiller, Isabella; Schädlich, Katja; Koitschev, Assen; Koitschev, Christiane; Riethmüller, Joachim; Graepler-Mainka, Uta; Wiedemann, Bärbel; Beck, James F

2014-07-01

Chronic rhinosinusitis significantly impairs CF patients' quality of life and overall health. The Pari-Sinus™ device delivers vibrating aerosol effectively to paranasal sinuses. After a small pilot study to assess sinonasal inhalation of dornase alfa and placebo (isotonic saline) on potential sinonasal outcome measures, we present the subsequent prospective double-blind placebo-controlled crossover-trial. 23 CF patients were randomised to inhale either dornase alfa or isotonic saline for 28 days with the Pari-Sinus™ and after 28 days (wash-out) crossed over to the alternative treatment. The primary outcome parameter was primary nasal symptom score in the disease-specific quality of life Sino-Nasal Outcome-Test-20 (SNOT-20: nasal obstruction/sneezing/runny nose/thick nasal discharge/reduced smelling). Primary nasal symptoms improved significantly with dornase alfa compared with no treatment, while small improvements with isotonic saline did not reach significance. SNOT-20 overall scores improved significantly after dornase alfa compared with isotonic saline (p=0.017). Additionally, sinonasal dornase alfa but not isotonic saline significantly improved pulmonary function (FEF75-25: p=0.021). Vibrating sinonasal inhalation of dornase alfa reduces rhinosinusitis symptoms in CF. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
Active video gaming improves body coordination in survivors of childhood brain tumours.

PubMed

Sabel, Magnus; Sjölund, Anette; Broeren, Jürgen; Arvidsson, Daniel; Saury, Jean-Michel; Blomgren, Klas; Lannering, Birgitta; Emanuelson, Ingrid

2016-10-01

We investigated whether active video gaming (AVG) could bring about regular, enjoyable, physical exercise in children treated for brain tumours, what level of physical activity could be reached and if the children's physical functioning improved. Thirteen children, aged 7-17 years, were randomised to either AVG or waiting-list. After 10-12 weeks they crossed-over. Weekly Internet coaching sessions were used to sustain motivation and evaluate enjoyment. Energy expenditure (EE) levels were measured as Metabolic Equivalent of Task (MET), using a multisensory activity monitor. Single-blinded assessments of physical functioning were done, using the Bruininks-Osteretsky Test of Motor Performance, second edition, evaluating participants before and after the intervention period, as well as comparing the randomisation groups after the first period. All patients completed the study. AVG sessions (mean duration 47 minutes) were performed on 72% of all days. Mean EE level during AVG sessions was 3.0 MET, corresponding to moderate physical activity. The Body Coordination score improved by 15% (p = 0.021) over the intervention period. In this group of childhood brain tumour survivors, home-based AVG, supported by a coach, was a feasible, enjoyable and moderately intense form of exercise that improved Body Coordination. Implications for Rehabilitation Childhood brain tumour survivors frequently have cognitive problems, inferior physical functioning and are less physically active compared to their healthy peers. Active video gaming (AVG), supported by Internet coaching, is a feasible home-based intervention in children treated for brain tumours, promoting enjoyable, regular physical exercise of moderate intensity. In this pilot study, AVG with Nintendo Wii improved Body Coordination.
Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults

PubMed Central

Chambers, Edward S; Viardot, Alexander; Psichas, Arianna; Morrison, Douglas J; Murphy, Kevin G; Zac-Varghese, Sagen E K; MacDougall, Kenneth; Preston, Tom; Tedford, Catriona; Finlayson, Graham S; Blundell, John E; Bell, Jimmy D; Thomas, E Louise; Mt-Isa, Shahrul; Ashby, Deborah; Gibson, Glen R; Kolida, Sofia; Dhillo, Waljit S; Bloom, Stephen R; Morley, Wayne; Clegg, Stuart; Frost, Gary

2015-01-01

Objective The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. Design To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. Results Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. Conclusions These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. Trial registration number NCT00750438. PMID:25500202
Prevention of Overweight in Infancy (POI.nz) study: a randomised controlled trial of sleep, food and activity interventions for preventing overweight from birth.

PubMed

Taylor, Barry J; Heath, Anne-Louise M; Galland, Barbara C; Gray, Andrew R; Lawrence, Julie A; Sayers, Rachel M; Dale, Kelly; Coppell, Kirsten J; Taylor, Rachael W

2011-12-19

Rapid weight gain during the first three years of life predicts child and adult obesity, and also later cardiovascular and other morbidities. Cross-sectional studies suggest that infant diet, activity and sleep are linked to excessive weight gain. As intervention for overweight children is difficult, the aim of the Prevention of Overweight in Infancy (POI.nz) study is to evaluate two primary prevention strategies during late pregnancy and early childhood that could be delivered separately or together as part of normal health care. This four-arm randomised controlled trial is being conducted with 800 families recruited at booking in the only maternity unit in the city of Dunedin, New Zealand. Mothers are randomised during pregnancy to either a usual care group (7 core contacts with a provider of government funded "Well Child" care over 2 years) or to one of three intervention groups given education and support in addition to "Well Child" care: the Food, Activity and Breastfeeding group which receives 8 extra parent contacts over the first 2 years of life; the Sleep group which receives at least 3 extra parent contacts over the first 6 months of life with a focus on prevention of sleep problems and then active intervention if there is a sleep problem from 6 months to 2 years; or the Combination group which receives all extra contacts. The main outcome measures are conditional weight velocity (0-6, 6-12, 12-24 months) and body mass index z-score at 24 months, with secondary outcomes including sleep and physical activity (parent report, accelerometry), duration of breastfeeding, timing of introduction of solids, diet quality, and measures of family function and wellbeing (parental depression, child mindedness, discipline practices, family quality of life and health care use). This study will contribute to a prospective meta-analysis of early life obesity prevention studies in Australasia. Infancy is likely to be the most effective time to establish patterns of behaviour around food, activity and sleep that promote healthy child and adult weight. The POI.nz study will determine the extent to which sleep, food and activity interventions in infancy prevent the development of overweight. Clinical Trials NCT00892983. Prospective meta-analysis registered on PROSPERO CRD420111188. Available from http://www.crd.york.ac.uk/PROSPERO.
Study protocol for the evaluation of an Infant Simulator based program delivered in schools: a pragmatic cluster randomised controlled trial

PubMed Central

2010-01-01

Background This paper presents the study protocol for a pragmatic randomised controlled trial to evaluate the impact of a school based program developed to prevent teenage pregnancy. The program includes students taking care of an Infant Simulator; despite growing popularity and an increasing global presence of such programs, there is no published evidence of their long-term impact. The aim of this trial is to evaluate the Virtual Infant Parenting (VIP) program by investigating pre-conceptual health and risk behaviours, teen pregnancy and the resultant birth outcomes, early child health and maternal health. Methods and Design Fifty-seven schools (86% of 66 eligible secondary schools) in Perth, Australia were recruited to the clustered (by school) randomised trial, with even randomisation to the intervention and control arms. Between 2003 and 2006, the VIP program was administered to 1,267 participants in the intervention schools, while 1,567 participants in the non-intervention schools received standard curriculum. Participants were all female and aged between 13-15 years upon recruitment. Pre and post-intervention questionnaires measured short-term impact and participants are now being followed through their teenage years via data linkage to hospital medical records, abortion clinics and education records. Participants who have a live birth are interviewed by face-to-face interview. Kaplan-Meier survival analysis and proportional hazards regression will test for differences in pregnancy, birth and abortion rates during the teenage years between the study arms. Discussion This protocol paper provides a detailed overview of the trial design as well as initial results in the form of participant flow. The authors describe the intervention and its delivery within the natural school setting and discuss the practical issues in the conduct of the trial, including recruitment. The trial is pragmatic and will directly inform those who provide Infant Simulator based programs in school settings. Trial registration ISRCTN24952438 PMID:20964860
Study protocol for the evaluation of an Infant Simulator based program delivered in schools: a pragmatic cluster randomised controlled trial.

PubMed

Brinkman, Sally A; Johnson, Sarah E; Lawrence, David; Codde, James P; Hart, Michael B; Straton, Judith A Y; Silburn, Sven

2010-10-21

This paper presents the study protocol for a pragmatic randomised controlled trial to evaluate the impact of a school based program developed to prevent teenage pregnancy. The program includes students taking care of an Infant Simulator; despite growing popularity and an increasing global presence of such programs, there is no published evidence of their long-term impact. The aim of this trial is to evaluate the Virtual Infant Parenting (VIP) program by investigating pre-conceptual health and risk behaviours, teen pregnancy and the resultant birth outcomes, early child health and maternal health. Fifty-seven schools (86% of 66 eligible secondary schools) in Perth, Australia were recruited to the clustered (by school) randomised trial, with even randomisation to the intervention and control arms. Between 2003 and 2006, the VIP program was administered to 1,267 participants in the intervention schools, while 1,567 participants in the non-intervention schools received standard curriculum. Participants were all female and aged between 13-15 years upon recruitment. Pre and post-intervention questionnaires measured short-term impact and participants are now being followed through their teenage years via data linkage to hospital medical records, abortion clinics and education records. Participants who have a live birth are interviewed by face-to-face interview. Kaplan-Meier survival analysis and proportional hazards regression will test for differences in pregnancy, birth and abortion rates during the teenage years between the study arms. This protocol paper provides a detailed overview of the trial design as well as initial results in the form of participant flow. The authors describe the intervention and its delivery within the natural school setting and discuss the practical issues in the conduct of the trial, including recruitment. The trial is pragmatic and will directly inform those who provide Infant Simulator based programs in school settings. ISRCTN24952438.
Pulsatile luteinising hormone releasing hormone for ovulation induction in subfertility associated with polycystic ovary syndrome.

PubMed

Bayram, N; van Wely, M; Vandekerckhove, P; Lilford, R; van Der Veen, F

2000-01-01

In normal menstrual cycles, gonadotrophin releasing hormone (GnRH) secretion is pulsatile, with intervals of 60-120 minutes in the follicular phase. Treatment with pulsatile GnRH infusion by the intra-venous or subcutaneous route using a portable pump has been used successfully in patients with hypogonadotrophic hypogonadism. Assuming that the results would be similar in polycystic ovary syndrome (PCOS), pulsatile GnRH has been used to induce ovulation in patients with PCOS. But, although ovulation and pregnancy has been achieved, the use of pulsatile GnRH in PCOS patients is controversial. To assess the effectiveness of pulsatile GnRH administration in women with clomiphene-resistant polycystic ovary syndrome (PCOS), in terms of ovulation induction, pregnancy, miscarriage, multiple pregnancy and ovarian hyperstimulation syndrome (OHSS). The search strategy of the Menstrual Disorders and Subfertility review group was used to identify all relevant trials. Please see Review Group details. All relevant published RCTs were selected. Non-randomised controlled trials were eligible for inclusion if treatment consisted of GnRH administration versus another treatment to induce ovulation in subfertile women with PCOS. A computerised MEDLINE and EMBASE search was used to identify randomised and non randomised controlled trials. The reference lists of all studies found were checked for relevant articles. One RCT (Bringer 1985a) and one abstract (Coelingh 1983) were identified this way. Relevant data were extracted independently by two reviewers (NB, MW). Validity was assessed in terms of method of randomization, completeness of follow-up, presence or absence of cross-over and co-intervention. All trials were screened and analysed for predetermined quality criteria. 2X2 tables were generated for all the relevant outcomes. Odds ratios were generated using the Peto modified Mantel-Haenszel technique. Three RCTs and one non-randomised comparative trial were identified comparing four different treatments: GnRH versus HMG, GnRH following GnRHa pre-treatment versus no pre-treatment, GnRH and FSH versus FSH, and GnRH following GnRHa pre-treatment versus GnRH following oral contraceptive pre-treatment. This means that there was only one trial in any one comparison. In the first two studies, data of pre- and post-cross-over were not described separately. Therefore, these results could not be included in the MetaView analysis. The odds ratio for ovulation rate was 16 (95 % CI: 1.1-239) in the study comparing GnRH and FSH with FSH. When GnRH after GnRHa pre-treatment was compared with GnRH after oral contraceptive pre-treatment, an odds ratio of 7.5 (95 % CI: 1.2-46) was obtained. All trials were small and of too short duration to show any significance in pregnancy results. Per study only one to four pregnancies occurred. Multiple pregnancies were not seen. OHSS was seen only in the patients stimulated with HMG. The four trials describing four different comparisons with a short follow up (1 to 3 cycles) were too small to either prove or discard the value of pulsatile GnRH treatment in patients with polycystic ovary syndrome.
Antepartum dalteparin versus no antepartum dalteparin for the prevention of pregnancy complications in pregnant women with thrombophilia (TIPPS): a multinational open-label randomised trial.

PubMed

Rodger, Marc A; Hague, William M; Kingdom, John; Kahn, Susan R; Karovitch, Alan; Sermer, Mathew; Clement, Anne Marie; Coat, Suzette; Chan, Wee Shian; Said, Joanne; Rey, Evelyne; Robinson, Sue; Khurana, Rshmi; Demers, Christine; Kovacs, Michael J; Solymoss, Susan; Hinshaw, Kim; Dwyer, James; Smith, Graeme; McDonald, Sarah; Newstead-Angel, Jill; McLeod, Anne; Khandelwal, Meena; Silver, Robert M; Le Gal, Gregoire; Greer, Ian A; Keely, Erin; Rosene-Montella, Karen; Walker, Mark; Wells, Philip S

2014-11-08

Thrombophilias are common disorders that increase the risk of pregnancy-associated venous thromboembolism and pregnancy loss and can also increase the risk of placenta-mediated pregnancy complications (severe pre-eclampsia, small-for-gestational-age infants, and placental abruption). We postulated that antepartum dalteparin would reduce these complications in pregnant women with thrombophilia. In this open-label randomised trial undertaken in 36 tertiary care centres in five countries, we enrolled consenting pregnant women with thrombophilia at increased risk of venous thromboembolism or with previous placenta-mediated pregnancy complications. Eligible participants were randomly allocated in a 1:1 ratio to either antepartum prophylactic dose dalteparin (5000 international units once daily up to 20 weeks' gestation, and twice daily thereafter until at least 37 weeks' gestation) or to no antepartum dalteparin (control group). Randomisation was done by a web-based randomisation system, and was stratified by country and gestational age at randomisation day with a permuted block design (block sizes 4 and 8). At randomisation, site pharmacists (or delegates) received a randomisation number and treatment allocation (by fax and/or e-mail) from the central web randomisation system and then dispensed study drug to the local coordinator. Patients and study personnel were not masked to treatment assignment, but the outcome adjudicators were masked. The primary composite outcome was independently adjudicated severe or early-onset pre-eclampsia, small-for-gestational-age infant (birthweight <10th percentile), pregnancy loss, or venous thromboembolism. We did intention-to-treat and on-treatment analyses. This trial is registered with ClinicalTrials.gov, number NCT00967382, and with Current Controlled Trials, number ISRCTN87441504. Between Feb 28, 2000, and Sept 14, 2012, 292 women consented to participate and were randomly assigned to the two groups. Three women were excluded after randomisation because of ineligibility (two in the antepartum dalteparin group and one in the control group), leaving 146 women assigned to antepartum dalteparin and 143 assigned to no antepartum dalteparin. Some patients crossed over to the other group during treatment, and therefore for on-treatment and safety analysis there were 143 patients in the dalteparin group and 141 in the no dalteparin group. Dalteparin did not reduce the incidence of the primary composite outcome in both intention-to-treat analysis (dalteparin 25/146 [17·1%; 95% CI 11·4-24·2%] vs no dalteparin 27/143 [18·9%; 95% CI 12·8-26·3%]; risk difference -1·8% [95% CI -10·6% to 7·1%)) and on-treatment analysis (dalteparin 28/143 [19·6%] vs no dalteparin 24/141 [17·0%]; risk difference +2·6% [95% CI -6·4 to 11·6%]). In safety analysis, the occurrence of major bleeding did not differ between the two groups. However, minor bleeding was more common in the dalteparin group (28/143 [19·6%]) than in the no dalteparin group (13/141 [9·2%]; risk difference 10·4%, 95% CI 2·3-18·4; p=0·01). Antepartum prophylactic dalteparin does not reduce the occurrence of venous thromboembolism, pregnancy loss, or placenta-mediated pregnancy complications in pregnant women with thrombophilia at high risk of these complications and is associated with an increased risk of minor bleeding. Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, and Pharmacia and UpJohn. Copyright © 2014 Elsevier Ltd. All rights reserved.
Study of the therapeutic effects of an advanced hippotherapy simulator in children with cerebral palsy: a randomised controlled trial.

PubMed

Herrero, Pablo; Asensio, Angel; García, Elena; Marco, Alvaro; Oliván, Barbara; Ibarz, Alejandro; Gómez-Trullén, Eva M; Casas, Roberto

2010-04-16

Although hippotherapy treatment has been demonstrated to have therapeutic effects on children with cerebral palsy, the samples used in research studies have been very small. In the case of hippotherapy simulators, there are no studies that either recommend or advise against their use in the treatment of children with cerebral palsy. The aim of this randomised clinical study is to analyse the therapeutic effects or the contraindications of the use of a commercial hippotherapy simulator on several important factors relating to children with cerebral palsy such as their motor development, balance control in the sitting posture, hip abduction range of motion and electromyographic activity of adductor musculature. The study is a randomised controlled trial. It will be carried out with a sample of 37 children with cerebral palsy divided into two treatment groups. Eligible participants will be randomly allocated to receive either (a) Treatment Group with hippotherapy simulator, maintaining sitting posture, with legs in abduction and rhythmic movement of the simulator or (b) Treatment Group maintaining sitting posture, with legs in abduction and without rhythmic movement of the simulator. all measurements will be carried out by a specially trained blind assessor. To ensure standardization quality of the assessors, an inter-examiner agreement will be worked out at the start of the study. The trial is funded by the Department of Research, Innovation and Development of the Regional Government of Aragon (Official Bulletin of Aragon 23 July 2007), project number PM059/2007. Interest in this project is due to the following factors: Clinical originality (there are no previous studies analysing the effect of simulators on the population group of children with CP, nor any studies using as many variables as this project); Clinical impact (infantile cerebral palsy is a chronic multisystemic condition that affects not only the patient but also the patient's family and their close circle of friends); Practical benefits (the development of an effective treatment is very important for introducing this element into the rehabilitation of these children). Current Controlled Trials ISRCTN03663478.
Association between bibliometric parameters, reporting and methodological quality of randomised controlled trials in vascular and endovascular surgery.

PubMed

Hajibandeh, Shahab; Hajibandeh, Shahin; Antoniou, George A; Green, Patrick A; Maden, Michelle; Torella, Francesco

2017-04-01

Purpose We aimed to investigate association between bibliometric parameters, reporting and methodological quality of vascular and endovascular surgery randomised controlled trials. Methods The most recent 75 and oldest 75 randomised controlled trials published in leading journals over a 10-year period were identified. The reporting quality was analysed using the CONSORT statement, and methodological quality with the Intercollegiate Guidelines Network checklist. We used exploratory univariate and multivariable linear regression analysis to investigate associations. Findings Bibliometric parameters such as type of journal, study design reported in title, number of pages; external funding, industry sponsoring and number of citations are associated with reporting quality. Moreover, parameters such as type of journal, subject area and study design reported in title are associated with methodological quality. Conclusions The bibliometric parameters of randomised controlled trials may be independent predictors for their reporting and methodological quality. Moreover, the reporting quality of randomised controlled trials is associated with their methodological quality and vice versa.
Cancer Research in the Arab World

PubMed Central

Hamadeh, Randah R.; Borgan, Saif M.; Sibai, Abla M.

2017-01-01

This review aimed to examine trends in cancer research in the Arab world and identify existing research gaps. A search of the MEDLINE® database (National Library of Medicine, Bethesda, Maryland, USA) was undertaken for all cancer-related publications published between January 2000 and December 2013 from seven countries, including Bahrain, Kuwait, Iraq, Lebanon, Morocco, Palestine and Sudan. A total of 1,773 articles were identified, with a significant increase in yearly publications over time (P <0.005). Only 30.6% of the publications included subjects over the age of 50 years old. There was a dearth of cross-sectional/correlational studies (8.8%), randomised controlled trials (2.4%) and systematic reviews/meta-analyses (1.3%). Research exploring cancer associations mainly considered social and structural determinants of health (27.1%), followed by behavioural risk factors (14.1%), particularly tobacco use. Overall, more cancer research is needed in the Arab world, particularly analytical studies with high-quality evidence and those focusing on older age groups and associations with physical activity and diet. PMID:28690885
A review of reporting of participant recruitment and retention in RCTs in six major journals

PubMed Central

Toerien, Merran; Brookes, Sara T; Metcalfe, Chris; de Salis, Isabel; Tomlin, Zelda; Peters, Tim J; Sterne, Jonathan; Donovan, Jenny L

2009-01-01

Background Poor recruitment and retention of participants in randomised controlled trials (RCTs) is problematic but common. Clear and detailed reporting of participant flow is essential to assess the generalisability and comparability of RCTs. Despite improved reporting since the implementation of the CONSORT statement, important problems remain. This paper aims: (i) to update and extend previous reviews evaluating reporting of participant recruitment and retention in RCTs; (ii) to quantify the level of participation throughout RCTs. Methods We reviewed all reports of RCTs of health care interventions and/or processes with individual randomisation, published July–December 2004 in six major journals. Short, secondary or interim reports, and Phase I/II trials were excluded. Data recorded were: general RCT details; inclusion of flow diagram; participant flow throughout trial; reasons for non-participation/withdrawal; target sample sizes. Results 133 reports were reviewed. Overall, 79% included a flow diagram, but over a third were incomplete. The majority reported the flow of participants at each stage of the trial after randomisation. However, 40% failed to report the numbers assessed for eligibility. Percentages of participants retained at each stage were high: for example, 90% of eligible individuals were randomised, and 93% of those randomised were outcome assessed. On average, trials met their sample size targets. However, there were some substantial shortfalls: for example 21% of trials reporting a sample size calculation failed to achieve adequate numbers at randomisation, and 48% at outcome assessment. Reporting of losses to follow up was variable and difficult to interpret. Conclusion The majority of RCTs reported the flow of participants well after randomisation, although only two-thirds included a complete flow chart and there was great variability over the definition of "lost to follow up". Reporting of participant eligibility was poor, making assessments of recruitment practice and external validity difficult. Reporting of participant flow throughout RCTs could be improved by small changes to the CONSORT chart. PMID:19591685
A review of reporting of participant recruitment and retention in RCTs in six major journals.

PubMed

Toerien, Merran; Brookes, Sara T; Metcalfe, Chris; de Salis, Isabel; Tomlin, Zelda; Peters, Tim J; Sterne, Jonathan; Donovan, Jenny L

2009-07-10

Poor recruitment and retention of participants in randomised controlled trials (RCTs) is problematic but common. Clear and detailed reporting of participant flow is essential to assess the generalisability and comparability of RCTs. Despite improved reporting since the implementation of the CONSORT statement, important problems remain. This paper aims: (i) to update and extend previous reviews evaluating reporting of participant recruitment and retention in RCTs; (ii) to quantify the level of participation throughout RCTs. We reviewed all reports of RCTs of health care interventions and/or processes with individual randomisation, published July-December 2004 in six major journals. Short, secondary or interim reports, and Phase I/II trials were excluded. Data recorded were: general RCT details; inclusion of flow diagram; participant flow throughout trial; reasons for non-participation/withdrawal; target sample sizes. 133 reports were reviewed. Overall, 79% included a flow diagram, but over a third were incomplete. The majority reported the flow of participants at each stage of the trial after randomisation. However, 40% failed to report the numbers assessed for eligibility. Percentages of participants retained at each stage were high: for example, 90% of eligible individuals were randomised, and 93% of those randomised were outcome assessed. On average, trials met their sample size targets. However, there were some substantial shortfalls: for example 21% of trials reporting a sample size calculation failed to achieve adequate numbers at randomisation, and 48% at outcome assessment. Reporting of losses to follow up was variable and difficult to interpret. The majority of RCTs reported the flow of participants well after randomisation, although only two-thirds included a complete flow chart and there was great variability over the definition of "lost to follow up". Reporting of participant eligibility was poor, making assessments of recruitment practice and external validity difficult. Reporting of participant flow throughout RCTs could be improved by small changes to the CONSORT chart.

The impact of constructive feedback on training in gastrointestinal endoscopy using high-fidelity Virtual-Reality simulation: a randomised controlled trial.

PubMed

Kruglikova, Irina; Grantcharov, Teodor P; Drewes, Asbjorn M; Funch-Jensen, Peter

2010-02-01

Recently, virtual reality computer simulators have been used to enhance traditional endoscopy teaching. Previous studies have demonstrated construct validity of these systems and transfer of virtual skills to the operating room. However, to date no simulator-training curricula have been designed and there is very little evidence on the impact of external feedback on acquisition of endoscopic skills. The aim of the present study was to assess the impact of external feedback on the learning curves on a VR colonoscopy simulator using inexperienced trainees. 22 trainees, without colonoscopy experience were randomised to a group which received structured feedback provided by an experienced supervisor and a controlled group. All participants performed 15 repetitions of task 3 from the Introduction colonoscopy module of the Accu Touch Endoscopy simulator. Retention/transfer tests on simulator were performed 4-6 weeks after the last repetition. The proficiency levels were based on the performance of eight experienced colonoscopists. All subjects were able to complete the procedure on the simulator. There were no perforations in the feedback group versus seven in the non-feedback group. Subjects in the feedback group reached expert proficiency levels in percentage of mucosa visualised and time to reach the caecum significantly faster compared with the control group. None of the groups demonstrated significant degradation of performance in simulator retention/transfer tests. Concurrent feedback given by supervisor concur an advantage in acquisition of basic colonoscopy skills and achieving of proficiency level as compared to independent training.
Investigating the relationship between predictability and imbalance in minimisation: a simulation study

PubMed Central

2013-01-01

Background The use of restricted randomisation methods such as minimisation is increasing. This paper investigates under what conditions it is preferable to use restricted randomisation in order to achieve balance between treatment groups at baseline with regard to important prognostic factors and whether trialists should be concerned that minimisation may be considered deterministic. Methods Using minimisation as the randomisation algorithm, treatment allocation was simulated for hypothetical patients entering a theoretical study having values for prognostic factors randomly assigned with a stipulated probability. The number of times the allocation could have been determined with certainty and the imbalances which might occur following randomisation using minimisation were examined. Results Overall treatment balance is relatively unaffected by reducing the probability of allocation to optimal treatment group (P) but within-variable balance can be affected by any P <1. This effect is magnified by increased numbers of prognostic variables, the number of categories within them and the prevalence of these categories within the study population. Conclusions In general, for smaller trials, probability of treatment allocation to the treatment group with fewer numbers requires a larger value P to keep treatment and variable groups balanced. For larger trials probability of allocation values from P = 0.5 to P = 0.8 can be used while still maintaining balance. For one prognostic variable there is no significant benefit in terms of predictability in reducing the value of P. However, for more than one prognostic variable, significant reduction in levels of predictability can be achieved with the appropriate choice of P for the given trial design. PMID:23537389
Investigating the relationship between predictability and imbalance in minimisation: a simulation study.

PubMed

McPherson, Gladys C; Campbell, Marion K; Elbourne, Diana R

2013-03-27

The use of restricted randomisation methods such as minimisation is increasing. This paper investigates under what conditions it is preferable to use restricted randomisation in order to achieve balance between treatment groups at baseline with regard to important prognostic factors and whether trialists should be concerned that minimisation may be considered deterministic. Using minimisation as the randomisation algorithm, treatment allocation was simulated for hypothetical patients entering a theoretical study having values for prognostic factors randomly assigned with a stipulated probability. The number of times the allocation could have been determined with certainty and the imbalances which might occur following randomisation using minimisation were examined. Overall treatment balance is relatively unaffected by reducing the probability of allocation to optimal treatment group (P) but within-variable balance can be affected by any P <1. This effect is magnified by increased numbers of prognostic variables, the number of categories within them and the prevalence of these categories within the study population. In general, for smaller trials, probability of treatment allocation to the treatment group with fewer numbers requires a larger value P to keep treatment and variable groups balanced. For larger trials probability of allocation values from P = 0.5 to P = 0.8 can be used while still maintaining balance. For one prognostic variable there is no significant benefit in terms of predictability in reducing the value of P. However, for more than one prognostic variable, significant reduction in levels of predictability can be achieved with the appropriate choice of P for the given trial design.
The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial.

PubMed

Melville, Geoffrey W; Siegler, Jason C; Marshall, Paul W M

2017-01-01

Research on d-aspartic acid (DAA) has demonstrated increases in total testosterone levels in untrained men, however research in resistance-trained men demonstrated no changes, and reductions in testosterone levels. The long-term consequences of DAA in a resistance trained population are currently unknown. To evaluate the effectiveness of DAA to alter basal testosterone levels over 3 months of resistance training in resistance-trained men. Randomised, double-blind, placebo controlled trial in healthy resistance-trained men, aged 18-36, had been performing regular resistance training exercise for at least 3 d.w-1 for the previous 2 years. Randomised participants were 22 men (d-aspartic acid n = 11; placebo n = 11) (age, 23.8±4.9 y, training age, 3.2±1.5 y). D-aspartic acid (6 g.d-1, DAA) versus equal-weight, visually-matched placebo (PLA). All participants performed 12 weeks of supervised, periodised resistance training (4 d.w-1), with a program focusing on all muscle groups. Basal hormones, total testosterone (TT), free testosterone (FT), estradiol (E2), sex-hormone-binding globulin (SHBG) and albumin (ALB); isometric strength; calf muscle cross-sectional area (CSA); calf muscle thickness; quadriceps muscle CSA; quadriceps muscle thickness; evoked V-wave and H-reflexes, were assessed at weeks zero (T1), after six weeks (T2) and after 12 weeks (T3). No change in basal TT or FT were observed after the intervention. DAA supplementation (n = 10) led to a 16%, 95% CI [-27%, -5%] reduction in E2 from T1-T3 (p<0.01). The placebo group (n = 9) demonstrated improvements in spinal responsiveness (gastrocnemius) at the level of the alpha motoneuron. Both groups exhibited increases in isometric strength of the plantar flexors by 17%, 95% CI [7%, 28%] (p<0.05) as well as similar increases in hypertrophy in the quadriceps and calf muscles. The results of this paper indicate that DAA supplementation is ineffective at changing testosterone levels, or positively affecting training outcomes. Reductions in estradiol and the blunting of peripheral excitability appear unrelated to improvements from resistance training. Australian New Zealand Clinical Trials Registry ACTRN12617000041358.
Effect of intruder mass on collisions with hard binaries. II - Dependence on impact parameter and computations of the interaction cross sections

NASA Astrophysics Data System (ADS)

Hills, J. G.

1992-06-01

Over 125,000 encounters between a hard binary with equal mass, components and orbital eccentricity of 0, and intruders with solar masses ranging from 0.01 to 10,000 are simulated. Each encounter was followed up to a maximum of 5 x 10 exp 6 integration steps to allow long-term 'resonances', temporary trinary systems, to break into a binary and a single star. These simulations were done over a range of impact parameters to find the cross sections for various processes occurring in these encounters. A critical impact parameter found in these simulations is the one beyond which no exchange collisions can occur. The energy exchange between the binary and a massive intruder decreases greatly in collisions with Rmin of not less than Rc. The semimajor axes and orbital eccentricity of the surviving binary also drops rapidly at Rc in encounters with massive intruders. The formation of temporary trinary systems is important for all intruder masses.
Investigation of novel fractal shape of the nano-aperture as a metasurface for bio sensing application

NASA Astrophysics Data System (ADS)

Heydari, Samaneh; Rastan, Iman; Parvin, Amin; Pirooj, Azadeh; Zarrabi, Ferdows B.

2017-01-01

Recently, nano-aperture is noticed due to its good transmission in the optical regime. Also, the nano-apertures are developed at the metasurface design for circular polarization; for this aim, various shapes of the nano-aperture are suggested. To reach this objective, we have developed a novel Jerusalem cross fractal shape for a mid-infrared application. We have simulated various formations of the nano-fractal Jerusalem cross based on a simple cross to show the effect of nano-aperture shape on electrical field enhancement in the near-field which is important in spectroscopy and optical imaging. In addition, we have used a single layer graphene over the aperture as a coat for making reconfigurable characteristic also creating a membrane for placement of nano-particle over the aperture. Implementation of the graphene is an amendment to the transfer of the nano-apertures. The biological materials with a thickness of 80 nm have been placed over the graphene layer and the Figures of Merits (FOM) have been obtained. Additionally, the prototype of nano-antenna is independent from incident wave polarization. The Finite Difference Time Domain (FDTD) calculations have been implemented in the simulation and modeling the nano-apertures.
The role of cognitive training in endourology: a randomised controlled trial.

PubMed

Shah, M; Aydin, A; Moran, A; Khan, M S; Dasgupta, P; Ahmed, K

2018-04-01

Cognitive training is an important training modality which allows the user to rehearse a procedure without physically carrying it out. This has led to recent interests to incorporate cognitive training within surgical education but research is currently limited. The use of cognitive training in surgery is not clear-cut and so this study aimed to determine whether, relative to a control condition, the use of cognitive training improves technical surgical skills on a ureteroscopy simulator, and if so whether one cognitive training method is superior. This prospective, comparative study recruited 59 medical students and randomised them to one of three groups: control- simulation training only (n=20), flashcards cognitive training group (n=20) or mental imagery cognitive training group (n=19). All participants completed three tasks at baseline on the URO Mentor simulator followed by the cognitive intervention if randomised to receive it. Participants then returned to perform an assessment task on the simulator. Outcome measures from the URO Mentor performance report was used for analysis and a quantitative survey was given to all participants to assess usefulness of training received. This study showed cognitive training to have minimal effects on technical skills of participants. The mental imagery group had fewer laser misfires in the assessment task when compared to both control and flashcards group (P=.017, P=.036, respectively). The flashcards group rated their preparation to be most useful when compared to control (P=.0125). Other parameters analysed between the groups did not reach statistical significance. Cognitive training was found to be feasible and cost effective when carried out in addition to simulation training. This study has shown that the role of cognitive training within acquisition of surgical skills is minimal and that no form of cognitive training was superior to another. Further research needs to be done to evaluate other ways of performing cognitive training. Copyright © 2017. Publicado por Elsevier España, S.L.U.
Te Ira Tangata: a Zelen randomised controlled trial of a treatment package including problem solving therapy compared to treatment as usual in Maori who present to hospital after self harm.

PubMed

Hatcher, Simon; Coupe, Nicole; Durie, Mason; Elder, Hinemoa; Tapsell, Rees; Wikiriwhi, Karen; Parag, Varsha

2011-05-11

Maori, the indigenous people of New Zealand, who present to hospital after intentionally harming themselves, do so at a higher rate than non-Maori. There have been no previous treatment trials in Maori who self harm and previous reviews of interventions in other populations have been inconclusive as existing trials have been under powered and done on unrepresentative populations. These reviews have however indicated that problem solving therapy and sending regular postcards after the self harm attempt may be an effective treatment. There is also a small literature on sense of belonging in self harm and the importance of culture. This protocol describes a pragmatic trial of a package of measures which include problem solving therapy, postcards, patient support, cultural assessment, improved access to primary care and a risk management strategy in Maori who present to hospital after self harm using a novel design. We propose to use a double consent Zelen design where participants are randomised prior to giving consent to enrol a representative cohort of patients. The main outcome will be the number of Maori scoring below nine on the Beck Hopelessness Scale. Secondary outcomes will be hospital repetition at one year; self reported self harm; anxiety; depression; quality of life; social function; and hospital use at three months and one year. A strength of the study is that it is a pragmatic trial which aims to recruit Maori using a Maori clinical team and protocol. It does not exclude people if English is not their first language. A potential limitation is the analysis of the results which is complex and may underestimate any effect if a large number of people refuse their consent in the group randomised to problem solving therapy as they will effectively cross over to the treatment as usual group. This study is the first randomised control trial to explicitly use cultural assessment and management. Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000952246.
Te Ira Tangata: A Zelen randomised controlled trial of a treatment package including problem solving therapy compared to treatment as usual in Maori who present to hospital after self harm

PubMed Central

2011-01-01

Background Maori, the indigenous people of New Zealand, who present to hospital after intentionally harming themselves, do so at a higher rate than non-Maori. There have been no previous treatment trials in Maori who self harm and previous reviews of interventions in other populations have been inconclusive as existing trials have been under powered and done on unrepresentative populations. These reviews have however indicated that problem solving therapy and sending regular postcards after the self harm attempt may be an effective treatment. There is also a small literature on sense of belonging in self harm and the importance of culture. This protocol describes a pragmatic trial of a package of measures which include problem solving therapy, postcards, patient support, cultural assessment, improved access to primary care and a risk management strategy in Maori who present to hospital after self harm using a novel design. Methods We propose to use a double consent Zelen design where participants are randomised prior to giving consent to enrol a representative cohort of patients. The main outcome will be the number of Maori scoring below nine on the Beck Hopelessness Scale. Secondary outcomes will be hospital repetition at one year; self reported self harm; anxiety; depression; quality of life; social function; and hospital use at three months and one year. Discussion A strength of the study is that it is a pragmatic trial which aims to recruit Maori using a Maori clinical team and protocol. It does not exclude people if English is not their first language. A potential limitation is the analysis of the results which is complex and may underestimate any effect if a large number of people refuse their consent in the group randomised to problem solving therapy as they will effectively cross over to the treatment as usual group. This study is the first randomised control trial to explicitly use cultural assessment and management. Trial registration Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000952246 PMID:21569300
360° Operative Videos: A Randomised Cross-Over Study Evaluating Attentiveness and Information Retention.

PubMed

Harrington, Cuan M; Kavanagh, Dara O; Wright Ballester, Gemma; Wright Ballester, Athena; Dicker, Patrick; Traynor, Oscar; Hill, Arnold; Tierney, Sean

2017-11-06

Although two-dimensional (2D) and three-dimensional videos have traditionally provided foundations for reviewing operative procedures, the recent 360º format may provide new dimensions to surgical education. This study sought to describe the production of a high quality 360º video for an index-operation (augmented with educational material), while evaluating for variances in attentiveness, information retention, and appraisal compared to 2D. A 6-camera synchronised array (GoPro Omni, [California, United States]) was suspended inverted and recorded an elective laparoscopic cholecystectomy in 2016. A single-blinded randomised cross-over study was performed to evaluate this video in 360º vs 2D formats. Group A experienced the 360º video using Samsung (Suwon, South-Korea) GearVR virtual-reality headsets, followed by the 2D experience on a 75-inch television. Group B were reversed. Each video was probed at designated time points for engagement levels and task-unrelated images or thoughts. Alternating question banks were administered following each video experience. Feedback was obtained via a short survey at study completion. The New Academic and Education Building (NAEB) in Dublin, Royal College of Surgeons in Ireland, July 2017. Preclinical undergraduate students from a medical university in Ireland. Forty students participated with a mean age of 23.2 ± 4.5 years and equal sex involvement. The 360º video demonstrated significantly higher engagement (p < 0.01) throughout the experience and lower task-unrelated images or thoughts (p < 0.01). Significant variances in information retention between the 2 groups were absent (p = 0.143) but most (65%) reported the 360º video as their learning platform of choice. Mean appraisal levels for the 360º platform were positive with mean responses of >8/10 for the platform for learning, immersion, and entertainment. This study describes the successful development and evaluation of a 360º operative video. This new video format demonstrated significant engagement and attentiveness benefits compared to traditional 2D formats. This requires further evaluation in the field of technology enhanced learning. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
A randomised cross-over trial in healthy adults indicating improved absorption of omega-3 fatty acids by pre-emulsification

PubMed Central

Garaiova, Iveta; Guschina, Irina A; Plummer, Sue F; Tang, James; Wang, Duolao; Plummer, Nigel T

2007-01-01

Background The health benefits of increased intakes of omega-3 fatty acids are well established but palatability often presents a problem. The process of emulsification is used in the food industry to provide a wider spectrum of use, often with the result of increased consumption. Moreover, as emulsification is an important step in the digestion and absorption of fats, the pre-emulsification process may enhance digestion and absorption. In this study the levels of plasma fatty acid and triacylglycerol (TAG) following the ingestion of either an oil mixture or an emulsified oil mixture have been compared. Methods In this randomised cross-over study, 13 volunteers received the oil mixture and 11 received the oil emulsion as part of an otherwise fat free meal. Blood samples were collected at 0, 1.5, 3, 4.5, 6, 7.5 and 9 hours after ingestion of oil, separated and stored at -20°C. Plasma triacylglycerols were assessed spectrophotometrically and fatty acids were determined by gas chromatography. Following a washout period of twenty days the procedure was repeated with the assignments reversed. Results The postprandial plasma TAG and the C18:3 (n-6), C18:3(n-3), C20:5(n-3) and C22:6 (n-3) polyunsaturated fatty acid (PUFA) levels for the emulsified oil group were increased significantly (P = 0.0182; P = 0.0493; P = 0.0137; P < 0.0001; P = 0.0355 respectively) compared with the non-emulsified oil group. The C16:0 and C18:0 saturated fatty acids, the C18:1 (n-9) monounsaturated fatty acid and the C18:2 PUFA were not significantly different for the oil and emulsified oil groups. Conclusion Pre-emulsification of an oil mixture prior to ingestion increases the absorption of longer chain more highly unsaturated fatty acids (especially eicosapentaenoic acid and docosahexaenoic acid) but does not affect absorption of shorter chain less saturated fatty acids, suggesting that pre-emulsification of fish oils may be a useful means of boosting absorption of these beneficial fatty acids. Trial registration: Current Controlled Trials ISRCTN43202606 PMID:17254329
Renal and Cardiovascular Effects of sodium–glucose cotransporter 2 (SGLT2) inhibition in combination with loop Diuretics in diabetic patients with Chronic Heart Failure (RECEDE-CHF): protocol for a randomised controlled double-blind cross-over trial

PubMed Central

Mordi, Natalie A; Mordi, Ify R; Singh, Jagdeep S; Baig, Fatima; Choy, Anna-Maria; McCrimmon, Rory J; Struthers, Allan D; Lang, Chim C

2017-01-01

Introduction Type 2 diabetes (T2D) and heart failure (HF) are a frequent combination, where treatment options remain limited. There has been increasing interest around the sodium–glucose cotransporter 2 (SGLT2) inhibitors and their use in patients with HF. Data on the effect of SGLT2 inhibitor use with diuretics are limited. We hypothesise that SGLT2 inhibition may augment the effects of loop diuretics and the benefits of SGLT2 inhibitors may extend beyond those of their metabolic (glycaemic parameters and weight loss) and haemodynamic parameters. The effects of SGLT2 inhibitors as an osmotic diuretic and on natriuresis may underlie the cardiovascular and renal benefits demonstrated in the recent EMPA-REG study. Methods and analysis To assess the effect of SGLT2 inhibitors when used in combination with a loop diuretic, the RECEDE-CHF (Renal and Cardiovascular Effects of SGLT2 inhibition in combination with loop Diuretics in diabetic patients with Chronic Heart Failure) trial is a single-centre, randomised, double-blind, placebo-controlled, cross-over trial conducted in a secondary care setting within NHS Tayside, Scotland. 34 eligible participants, aged between 18 and 80 years, with stable T2D and CHF will be recruited. Renal physiological testing will be performed at two points (week 1 and week 6) on each arm to assess the effect of 25 mg empagliflozin, on the primary and secondary outcomes. Participants will be enrolled in the trial for a total period between 14 and 16 weeks. The primary outcome will assess the effect of empagliflozin versus placebo on urine output. The secondary outcomes are to assess the effect of empagliflozin on glomerular filtration rate, cystatin C, urinary sodium excretion, urinary protein/creatinine ratio and urinary albumin/creatinine ratio when compared with placebo. Ethics and dissemination Ethics approval was obtained by the East of Scotland Research Ethics Service. Results of the trial will be submitted for publication in a peer-reviewed journal. Trial registration number NCT03226457; Pre-results. PMID:29042392
Effect of supplementation of fermented milk drink containing probiotic Lactobacillus casei Shirota on the concentrations of aflatoxin biomarkers among employees of Universiti Putra Malaysia: a randomised, double-blind, cross-over, placebo-controlled study.

PubMed

Mohd Redzwan, Sabran; Abd Mutalib, Mohd Sokhini; Wang, Jia-Sheng; Ahmad, Zuraini; Kang, Min-Su; Abdul Rahman, Nurul 'Aqilah; Nikbakht Nasrabadi, Elham; Jamaluddin, Rosita

2016-01-14

Human exposure to aflatoxin is through the diet, and probiotics are able to bind aflatoxin and prevent its absorption in the small intestine. This study aimed to determine the effectiveness of a fermented milk drink containing Lactobacillus casei Shirota (LcS) (probiotic drink) to prevent aflatoxin absorption and reduce serum aflatoxin B1-lysine adduct (AFB1-lys) and urinary aflatoxin M1 concentrations. The present study was a randomised, double-blind, cross-over, placebo-controlled study with two 4-week intervention phases. In all, seventy-one subjects recruited from the screening stage were divided into two groups--the Yellow group and the Blue group. In the 1st phase, one group received probiotic drinks twice a day and the other group received placebo drinks. Blood and urine samples were collected at baseline, 2nd and 4th week of the intervention. After a 2-week wash-out period, the treatments were switched between the groups, and blood and urine samples were collected at the 6th, 8th and 10th week (2nd phase) of the intervention. No significant differences in aflatoxin biomarker concentrations were observed during the intervention. A within-group analysis was further carried out. Aflatoxin biomarker concentrations were not significantly different in the Yellow group. Nevertheless, ANOVA for repeated measurements indicated that AFB1-lys concentrations were significantly different (P=0·035) with the probiotic intervention in the Blue group. The 2nd week AFB1-lys concentrations (5·14 (SD 2·15) pg/mg albumin (ALB)) were significantly reduced (P=0·048) compared with the baseline (6·24 (SD 3·42) pg/mg ALB). Besides, the 4th week AFB1-lys concentrations were significantly lower (P<0·05) with probiotic supplementation than with the placebo. Based on these findings, a longer intervention study is warranted to investigate the effects of continuous LcS consumption to prevent dietary aflatoxin exposure.
Metformin and dietary advice to improve insulin sensitivity and promote gestational restriction of weight among pregnant women who are overweight or obese: the GRoW Randomised Trial.

PubMed

Dodd, Jodie M; Grivell, Rosalie M; Deussen, Andrea R; Dekker, Gustaaf; Louise, Jennie; Hague, William

2016-11-21

Obesity is a significant global health problem, with approximately 50% of women entering pregnancy having a body mass index greater than or equal to 25 kg/m 2 . Obesity during pregnancy is associated with a well-recognised increased risk of adverse health outcomes both for the woman and her infant. Currently available data from large scale randomised trials and systematic reviews highlight only modest effects of antenatal dietary and lifestyle interventions in limiting gestational weight gain, with little impact on clinically relevant pregnancy outcomes. Further information evaluating alternative strategies is required. The aims of this randomised controlled trial are to assess whether the use of metformin as an adjunct therapy to dietary and lifestyle advice for overweight and obese women during pregnancy is effective in improving maternal, fetal and infant health outcomes. Design: Multicentre randomised, controlled trial. Women with a singleton, live gestation between 10 +0 -20 +0 weeks who are obese or overweight (defined as body mass index greater than or equal to 25 kg/m 2 ), at the first antenatal visit. Trial Entry & Randomisation: Eligible, consenting women will be randomised between 10 +0 and 20 +0 weeks gestation using an online computer randomisation system, and randomisation schedule prepared by non-clinical research staff with balanced variable blocks. Stratification will be according to maternal BMI at trial entry, parity, and centre where planned to give birth. Treatment Schedules: Women randomised to the Metformin Group will receive a supply of 500 mg oral metformin tablets. Women randomised to the Placebo Group will receive a supply of identical appearing and tasting placebo tablets. Women will be instructed to commence taking one tablet daily for a period of one week, increasing to a maximum of two tablets twice daily over four weeks and then continuing until birth. Women, clinicians, researchers and outcome assessors will be blinded to the allocated treatment group. All women will receive three face-to-face sessions (two with a research dietitian and one with a trained research assistant), and three telephone calls over the course of their pregnancy, in which they will be provided with dietary and lifestyle advice, and encouraged to make change utilising a SMART goals approach. Primary Study Outcome: infant birth weight >4000 grams. 524 women to detect a difference from 15.5% to 7.35% reduction in infants with birth weight >4000 grams (p = 0.05, 80% power, two-tailed). This is a protocol for a randomised trial. The findings will contribute to the development of evidence based clinical practice guidelines. Australian and New Zealand Clinical Trials Registry ACTRN12612001277831 , prospectively registered 10 th of December, 2012.
Simulation of digital mammography images

NASA Astrophysics Data System (ADS)

Workman, Adam

2005-04-01

A number of different technologies are available for digital mammography. However, it is not clear how differences in the physical performance aspects of the different imaging technologies affect clinical performance. Randomised controlled trials provide a means of gaining information on clinical performance however do not provide direct comparison of the different digital imaging technologies. This work describes a method of simulating the performance of different digital mammography systems. The method involves modifying the imaging performance parameters of images from a small field of view (SFDM), high resolution digital imaging system used for spot imaging. Under normal operating conditions this system produces images with higher signal-to-noise ratio (SNR) over a wide spatial frequency range than current full field digital mammography (FFDM) systems. The SFDM images can be 'degraded" by computer processing to simulate the characteristics of a FFDM system. Initial work characterised the physical performance (MTF, NPS) of the SFDM detector and developed a model and method for simulating signal transfer and noise properties of a FFDM system. It was found that the SNR properties of the simulated FFDM images were very similar to those measured from an actual FFDM system verifying the methodology used. The application of this technique to clinical images from the small field system will allow the clinical performance of different FFDM systems to be simulated and directly compared using the same clinical image datasets.
So you want to conduct a randomised trial? Learnings from a 'failed' feasibility study of a Crisis Resource Management prompt during simulated paediatric resuscitation.

PubMed

Teis, Rachel; Allen, Jyai; Lee, Nigel; Kildea, Sue

2017-02-01

No study has tested a Crisis Resource Management prompt on resuscitation performance. We conducted a feasibility, unblinded, parallel-group, randomised controlled trial at one Australian paediatric hospital (June-September 2014). Eligible participants were any doctor, nurse, or nurse manager who would normally be involved in a Medical Emergency Team simulation. The unit of block randomisation was one of six scenarios (3 control:3 intervention) with or without a verbal prompt. The primary outcomes tested the feasibility and utility of the intervention and data collection tools. The secondary outcomes measured resuscitation quality and team performance. Data were analysed from six resuscitation scenarios (n=49 participants); three control groups (n=25) and three intervention groups (n=24). The ability to measure all data items on the data collection tools was hindered by problems with the recording devices both in the mannequins and the video camera. For a pilot study, greater training for the prompt role and pre-briefing participants about assessment of their cardio-pulmonary resuscitation quality should be undertaken. Data could be analysed in real time with independent video analysis to validate findings. Two cameras would strengthen reliability of the methods. Copyright © 2016 College of Emergency Nursing Australasia. Published by Elsevier Ltd. All rights reserved.
Planned early delivery versus expectant management for monoamniotic twins.

PubMed

Shub, Alexis; Walker, Susan P

2015-04-23

Monoamniotic twin pregnancies are formed when a single egg is fertilised and the resulting inner cell mass splits to form twins sharing the same amniotic sac. This condition is rare and affects about one in 10,000 pregnancies overall. Monoamniotic twin pregnancies are susceptible to complications including cord entanglement, increased congenital anomalies, intrauterine growth restriction, twin-to-twin transfusion syndrome and increased perinatal mortality. All twin pregnancies also carry additional maternal risks including pre-eclampsia, anaemia, antepartum haemorrhage, postpartum haemorrhage and operative delivery.The optimal timing for the delivery of monoamniotic twins is not known. The options include 'planned early delivery' between 32 and 34 weeks, or alternatively awaiting spontaneous labour at least up until the usual time of planned delivery for other monochorionic twins (approximately 36 to 38 weeks' gestation), unless there is a specific indication for earlier delivery. To assess whether routine early delivery in monoamniotic twin pregnancies improves fetal, neonatal or maternal outcomes compared with 'expectant management'. Expectant management means awaiting spontaneous labour at least up until the usual time of planned delivery for other monochorionic twins (approximately 36 to 38 weeks' gestation in many centres), unless a specific indication for delivery occurs in the meantime, e.g. for non-reassuring antenatal testing. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2015). Published and unpublished randomised controlled trials (including cluster-randomised trials) comparing outcomes for women and infants who were randomised to planned early delivery of a monoamniotic twin pregnancy with outcomes for women and infants who were randomised to either planned term delivery or expectant management. However, we did not identify any trials for inclusion in this review.Quasi-randomised controlled trials, trials published in abstract form only, and trials using a cross-over design are not eligible for inclusion in this review. No trials were identified by the search strategy. No trials were identified by the search strategy. Monoamniotic twins are rare, and there is insufficient randomised controlled evidence on which to draw strong conclusions about the best management. In their absence, we can refer to historical case series and expert consensus. Management plans should take into consideration the availability of high-quality neonatal care if early delivery is chosen. Women and their families should be involved in the decision making about these high-risk pregnancies.Ongoing, multicentre audits of maternal and perinatal outcomes for monoamniotic twins are needed in order to inform families and clinicians about up-to-date perinatal outcomes with contemporary obstetric practice. Research should consider the social and economic implications of planned interventions, as well as the perinatal outcomes.
Double-blind randomised clinical trial of a pepsin-inhibitory pentapeptide (pepstatin) in the treatment of duodenal ulcer.

PubMed Central

Bonnevie, O; Svendsen, L B; Holst-Christensen, J; Johansen, T S; Søltoft, J; Christiansen, P M

1979-01-01

In a double-blind randomised clinical trial a specific inhibition of peptic activity with a pentapeptide, pepstatin, had no significant advantage over placebo in the ulcer healing and symptomatology of duodenal ulcer. Thus, the inhibition of pepsin in human gastric juice does not appear to have a major influence on the healing of duodenal ulcer. PMID:385457
A randomised crossover study to compare the cross-sectional and longitudinal approaches to ultrasound-guided peripheral venepuncture in a model.

PubMed

Griffiths, James; Carnegie, Amadeus; Kendall, Richard; Madan, Rajeev

2017-12-01

Ultrasound-guided peripheral intravenous access may present an alternative to central or intraosseous access in patients with difficult peripheral veins. Using venepuncture of a phantom model as a proxy, we investigated whether novice ultrasound users should adopt a cross-sectional or longitudinal approach when learning to access peripheral veins under ultrasound guidance. This result would inform the development of a structured training method for this procedure. We conducted a randomised controlled trial of 30 medical students. Subjects received 35 min of training, then attempted to aspirate 1 ml of synthetic blood from a deep vein in a training model under ultrasound guidance. Subjects attempted both the cross-sectional and longitudinal approaches. Group 1 used cross-sectional first, followed by longitudinal. Group 2 used longitudinal first, then cross-sectional. We measured the time from first puncture of the model's skin to aspiration of fluid, and the number of attempts required. Subjects also reported difficulty ratings for each approach. Paired sample t-tests were used for statistical analysis. The mean number of attempts was 1.13 using the cross-sectional approach, compared with 1.30 using the longitudinal approach (p = 0.17). Mean time to aspiration of fluid was 45.1 s using the cross-sectional approach and 52.8 s using the longitudinal approach (p = 0.43). The mean difficulty score out of 10 was 3.97 for the cross-sectional approach and 3.93 for the longitudinal approach (p = 0.95). We found no significant difference in effectiveness between the cross-sectional and longitudinal approaches to ultrasound-guided venepuncture when performed on a model. We believe that both approaches should be included when teaching ultrasound-guided peripheral vascular access. To confirm which approach would be best in clinical practice, we advocate future testing of both approaches on patients.
An Experimental Investigation of Intermittent Flow and Strain Burst Scaling Behavior in LiF Crystals During Microcompression Testing (Preprint)

DTIC Science & Technology

2010-01-01

or in more general terms, as a result of dislocation nucleation, motion, multiplication, and interaction). Nonetheless, state-of-the-art simulation ...computational power, together with under-developed physics within the simulation codes (i.e. cross-slip, climb, crystal rotations and patterning to...name a few), prevent realistic dislocation simulations over temporal and spatial domains that are readily accessible by experimental methods [9, 10

A kinematically complete, interdisciplinary, and co-institutional measurement of the 19F(α,n) cross section for nuclear safeguards science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, W. A.; Smith, M. S.; Pittman, S.

2016-05-01

Alpha particles emitted from the decay of uranium in a UF 6 matrix can interact with fluorine and generate neutrons via the 19F(α,n) 22Na reaction. These neutrons can be used to determine the uranium content in a UF 6 storage cylinder. The accuracy of this self-interrogating, non-destructive assay (NDA) technique is, however, limited by the uncertainty of the 19F(α,n) 22Na cross section. We have performed complementary measurements of the 19F(α,n) 22Na reaction with both 4He and 19F beams to improve the precision of the 19F(α,n) 22Na cross section over the alpha energy range that encompasses common actinide alpha decay neededmore » for NDA studies. We have determined an absolute cross section for the 19F(α,n) 22Na reaction to an average precision of 7.6% over the alpha energy range of 3.9 – 6.7 MeV. We utilized this cross section in a simulation of a 100 g spherical UF 6 assembly and obtained a change in neutron emission rate values of approximately 10-12%, and a significant (factor of 3.6) decrease in the neutron emission rate uncertainty (from 50-51% to 13-14%), compared to simulations using the old cross section. Our new absolute cross section enables improved interpretations of NDAs of containers of arbitrary size and configuration.« less
Importance of Preserving Cross-correlation in developing Statistically Downscaled Climate Forcings and in estimating Land-surface Fluxes and States

NASA Astrophysics Data System (ADS)

Das Bhowmik, R.; Arumugam, S.

2015-12-01

Multivariate downscaling techniques exhibited superiority over univariate regression schemes in terms of preserving cross-correlations between multiple variables- precipitation and temperature - from GCMs. This study focuses on two aspects: (a) develop an analytical solutions on estimating biases in cross-correlations from univariate downscaling approaches and (b) quantify the uncertainty in land-surface states and fluxes due to biases in cross-correlations in downscaled climate forcings. Both these aspects are evaluated using climate forcings available from both historical climate simulations and CMIP5 hindcasts over the entire US. The analytical solution basically relates the univariate regression parameters, co-efficient of determination of regression and the co-variance ratio between GCM and downscaled values. The analytical solutions are compared with the downscaled univariate forcings by choosing the desired p-value (Type-1 error) in preserving the observed cross-correlation. . For quantifying the impacts of biases on cross-correlation on estimating streamflow and groundwater, we corrupt the downscaled climate forcings with different cross-correlation structure.
Adjuvant chemotherapy in older women (ACTION) study – what did we learn from the pilot phase?

PubMed Central

Leonard, R; Ballinger, R; Cameron, D; Ellis, P; Fallowfield, L; Gosney, M; Johnson, L; Kilburn, L S; Makris, A; Mansi, J; Reed, M; Ring, A; Robinson, A; Simmonds, P; Thomas, G; Bliss, J M

2011-01-01

Background: The ACTION trial was initiated to provide evidence from a randomised trial on the effects of chemotherapy in women aged over 70 years where evidence for risk and benefit are lacking. Methods: This was a randomised, phase III clinical trial for high risk, oestrogen receptor (ER) negative/ER weakly positive early breast cancer. The trial planned to recruit 1000 women aged 70 years and older, randomised to receive 4 cycles of anthracycline chemotherapy or observation. The primary endpoint was relapse-free interval. The trial included a pilot phase to assess the acceptability and feasibility of recruitment. Results: The trial opened at 43 UK centres. Information on number of patients approached was available from 38 centres. Of the 43 eligible patients that were approached, 39 were not randomised due to patients declining entry. After 10 months only 4 patients had been randomised and after discussion with the research funder, the trial was closed and funding terminated. Conclusion: Despite widespread support at several public meetings, input from patient groups including representation on the Trial Management Group, the trial failed to recruit due to the inability to convince patients to accept randomisation. It would therefore seem that randomising the patients to receive chemotherapy vs observation is not a viable design in the current era for this patient population. PMID:21989185
Randomised prospective parallel trial of therapeutic versus subtherapeutic nasal continuous positive airway pressure on simulated steering performance in patients with obstructive sleep apnoea

PubMed Central

Hack, M.; Davies, R.; Mullins, R.; Choi, S. J.; Ramdassingh-Dow, S.; Jenkinson, C.; Stradling, J.

2000-01-01

BACKGROUND—Obstructive sleep apnoea (OSA) impairs vigilance and may lead to an increased rate of driving accidents. In uncontrolled studies accident rates and simulated steering performance improve following treatment with nasal continuous positive airway pressure (NCPAP). This study seeks to confirm the improvement in steering performance in a randomised controlled trial using subtherapeutic NCPAP as a control treatment. METHODS—Fifty nine men with OSA (Epworth Sleepiness Score (ESS) of ⩾10, and ⩾10/h dips in SaO2 of >4% due to OSA) received therapeutic or subtherapeutic NCPAP (≈1 cm H2O) for one month. Simulated steering performance over three 30-minute "drives" was quantified as: standard deviation (SD) of road position, deterioration in SD across the drive, length of drive before "crashing", and number of off-road events. The reaction times to peripheral target stimuli during the drive were also measured. RESULTS—Subtherapeutic NCPAP did not improve overnight >4% SaO2 dips/h compared with baseline values, thus acting as a control. The SD of the steering position improved from 0.36 to 0.21 on therapeutic NCPAP, and from 0.35 to 0.30 on subtherapeutic NCPAP (p = 0.03). Deterioration in SD of the steering position improved from 0.18to 0.06 SD/h with therapeutic NCPAP and worsened from 0.18 to 0.24 with subtherapeutic NCPAP (p = 0.04). The reaction time to target stimuli was quicker after therapeutic than after subtherapeutic NCPAP (2.3 versus 2.7 seconds, p = 0.04). CONCLUSIONS—Therapeutic NCPAP improves steering performance and reaction time to target stimuli in patients with OSA, lending further support to the hypothesis that OSA impairs driving, increases driving accident rates, and that these improve following treatment with NCPAP.   PMID:10679542
Atomistic modeling of thermomechanical properties of SWNT/Epoxy nanocomposites

NASA Astrophysics Data System (ADS)

Fasanella, Nicholas; Sundararaghavan, Veera

2015-09-01

Molecular dynamics simulations are performed to compute thermomechanical properties of cured epoxy resins reinforced with pristine and covalently functionalized carbon nanotubes. A DGEBA-DDS epoxy network was built using the ‘dendrimer’ growth approach where 75% of available epoxy sites were cross-linked. The epoxy model is verified through comparisons to experiments, and simulations are performed on nanotube reinforced cross-linked epoxy matrix using the CVFF force field in LAMMPS. Full stiffness matrices and linear coefficient of thermal expansion vectors are obtained for the nanocomposite. Large increases in stiffness and large decreases in thermal expansion were seen along the direction of the nanotube for both nanocomposite systems when compared to neat epoxy. The direction transverse to nanotube saw a 40% increase in stiffness due to covalent functionalization over neat epoxy at 1 K whereas the pristine nanotube system only saw a 7% increase due to van der Waals effects. The functionalized SWNT/epoxy nanocomposite showed an additional 42% decrease in thermal expansion along the nanotube direction when compared to the pristine SWNT/epoxy nanocomposite. The stiffness matrices are rotated over every possible orientation to simulate the effects of an isotropic system of randomly oriented nanotubes in the epoxy. The randomly oriented covalently functionalized SWNT/Epoxy nanocomposites showed substantial improvements over the plain epoxy in terms of higher stiffness (200% increase) and lower thermal expansion (32% reduction). Through MD simulations, we develop means to build simulation cells, perform annealing to reach correct densities, compute thermomechanical properties and compare with experiments.
Psychosocial morbidity in women with abnormal cervical cytology managed by cytological surveillance or initial colposcopy: longitudinal analysis from the TOMBOLA randomised trial.

PubMed

Fielding, S; Rothnie, K; Gray, N M; Little, J; Cruickshank, M E; Neal, K; Walker, L G; Whynes, D; Cotton, S C; Sharp, L

2017-04-01

To compare psychosocial outcomes (follow-up related worries and satisfaction with follow-up related information and support) over 30 months of two alternative management policies for women with low-grade abnormal cervical cytology. Women aged 20-59 years with low-grade cytological abnormalities detected in the National Health Service Cervical Screening Programme were randomised to cytological surveillance or initial colposcopy. A total of 3399 women who completed psychosocial questionnaires at recruitment were invited to complete questionnaires at 12, 18, 24 and 30 months. Linear mixed models were used to investigate differences between arms in the two psychosocial outcomes. Each outcome had a maximum score of 100, and higher scores represented higher psychosocial morbidity. On average, over 30 months, women randomised to colposcopy scored 2.5 points (95%CI -3.6 to -1.3) lower for follow-up related worries than women randomised to cytological surveillance. Women in the colposcopy arm also scored significantly lower for follow-up related satisfaction with information and support (-2.4; -3.3 to -1.4) over 30 months. For both outcomes, the average difference between arms was greatest at 12th- and 18th-month time points. These differences remained when the analysis was stratified by post-school education. Women with low-grade cytology, irrespective of their management, have substantial initial psychosocial morbidity that reduces over time. Implementation of newer screening strategies, which include surveillance, such as primary HPV screening, need to consider the information and support provided to women. © 2016 The Authors. Psycho-Oncology published by John Wiley & Sons Ltd. © 2016 The Authors. Psycho-Oncology published by John Wiley & Sons Ltd.
Effectiveness of traffic light vs. boom barrier controls at road-rail level crossings: a simulator study.

PubMed

Rudin-Brown, Christina M; Lenné, Michael G; Edquist, Jessica; Navarro, Jordan

2012-03-01

Although collisions at level crossings are relatively uncommon occurrences, the potential severity of their consequences make them a top priority among safety authorities. Twenty-five fully-licensed drivers aged between 20 and 50 years participated in a driving simulator study that compared the efficacy, and drivers' subjective perception, of two active level crossing traffic control devices: flashing lights with boom barriers and standard traffic lights. Because of its common usage in most states in Australia, a stop sign-controlled level crossing served as the passive referent. Although crossing violations were less likely at the level crossings controlled by active devices than at those controlled by stop signs, both kinds of active control were associated with a similar number of violations. Further, the majority (72%) of drivers reported preferring flashing lights to traffic lights. Collectively, results indicate that the installation of traffic lights at real-world level crossings would not be likely to offer safety benefits over and above those provided already by flashing lights with boom barriers. Furthermore, the high rate of violations at passively controlled crossings strongly supports the continued practice of upgrading level crossings with active traffic control devices. Copyright © 2011 Elsevier Ltd. All rights reserved.
Large-scale structure perturbation theory without losing stream crossing

NASA Astrophysics Data System (ADS)

McDonald, Patrick; Vlah, Zvonimir

2018-01-01

We suggest an approach to perturbative calculations of large-scale clustering in the Universe that includes from the start the stream crossing (multiple velocities for mass elements at a single position) that is lost in traditional calculations. Starting from a functional integral over displacement, the perturbative series expansion is in deviations from (truncated) Zel'dovich evolution, with terms that can be computed exactly even for stream-crossed displacements. We evaluate the one-loop formulas for displacement and density power spectra numerically in 1D, finding dramatic improvement in agreement with N-body simulations compared to the Zel'dovich power spectrum (which is exact in 1D up to stream crossing). Beyond 1D, our approach could represent an improvement over previous expansions even aside from the inclusion of stream crossing, but we have not investigated this numerically. In the process we show how to achieve effective-theory-like regulation of small-scale fluctuations without free parameters.
When and how should multiple imputation be used for handling missing data in randomised clinical trials - a practical guide with flowcharts.

PubMed

Jakobsen, Janus Christian; Gluud, Christian; Wetterslev, Jørn; Winkel, Per

2017-12-06

Missing data may seriously compromise inferences from randomised clinical trials, especially if missing data are not handled appropriately. The potential bias due to missing data depends on the mechanism causing the data to be missing, and the analytical methods applied to amend the missingness. Therefore, the analysis of trial data with missing values requires careful planning and attention. The authors had several meetings and discussions considering optimal ways of handling missing data to minimise the bias potential. We also searched PubMed (key words: missing data; randomi*; statistical analysis) and reference lists of known studies for papers (theoretical papers; empirical studies; simulation studies; etc.) on how to deal with missing data when analysing randomised clinical trials. Handling missing data is an important, yet difficult and complex task when analysing results of randomised clinical trials. We consider how to optimise the handling of missing data during the planning stage of a randomised clinical trial and recommend analytical approaches which may prevent bias caused by unavoidable missing data. We consider the strengths and limitations of using of best-worst and worst-best sensitivity analyses, multiple imputation, and full information maximum likelihood. We also present practical flowcharts on how to deal with missing data and an overview of the steps that always need to be considered during the analysis stage of a trial. We present a practical guide and flowcharts describing when and how multiple imputation should be used to handle missing data in randomised clinical.
Vaccine testing for emerging infections: the case for individual randomisation.

PubMed

Eyal, Nir; Lipsitch, Marc

2017-09-01

During the 2014-2015 Ebola outbreak in Guinea, Liberia and Sierra Leone, many opposed the use of individually randomised controlled trials to test candidate Ebola vaccines. For a raging fatal disease, they explained, it is unethical to relegate some study participants to control arms. In Zika and future emerging infections, similar opposition may hinder urgent vaccine research, so it is best to address these questions now. This article lays out the ethical case for individually randomised control in testing vaccines against many emerging infections, including lethal infections in low-income countries, even when at no point in the trial do the controls receive the countermeasures being tested. When individual randomisation is feasible-and it often will be-it tends to save more lives than alternative designs would. And for emerging infections, individual randomisation also tends as such to improve care, access to the experimental vaccine and prospects for all participants relative to their opportunities absent the trial, and no less than alternative designs would. That obtains even under placebo control and without equipoise-requiring which would undermine individual randomisation and the alternative designs that opponents proffered. Our arguments expound four often-neglected factors: benefits to non-participants, benefits to participants once a trial is over including post-trial access to the study intervention, participants' prospects before randomisation to arms and the near-inevitable disparity between arms in any randomised controlled trial. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Does oral alprazolam affect ventilation? A randomised, double-blind, placebo-controlled trial.

PubMed

Carraro, G E; Russi, E W; Buechi, S; Bloch, Konrad E

2009-05-01

The respiratory effects of benzodiazepines have been controversial. This investigation aimed to study the effects of oral alprazolam on ventilation. In a randomised, double-blind cross-over protocol, 20 healthy men ingested 1 mg of alprazolam or placebo in random order, 1 week apart. Ventilation was unobtrusively monitored by inductance plethysmography along with end-tidal PCO(2) and pulse oximetry 60-160 min after drug intake. Subjects were encouraged to keep their eyes open. Mean +/- SD minute ventilation 120 min after alprazolam and placebo was similar (6.21 +/- 0.71 vs 6.41 +/- 1.12 L/min, P = NS). End-tidal PCO(2) and oxygen saturation did also not differ between treatments. However, coefficients of variation of minute ventilation after alprazolam exceeded those after placebo (43 +/- 23% vs 31 +/- 13%, P < 0.05). More encouragements to keep the eyes open were required after alprazolam than after placebo (5.2 +/- 5.7 vs 1.3 +/- 2.3 calls, P < 0.05). In a multiple regression analysis, higher coefficients of variation of minute ventilation after alprazolam were related to a greater number of calls. Oral alprazolam in a mildly sedative dose has no clinically relevant effect on ventilation in healthy, awake men. The increased variability of ventilation on alprazolam seems related to vigilance fluctuations rather than to a direct drug effect on ventilation.
A randomised crossover study comparing bimatoprost and latanoprost in subjects with primary angle closure glaucoma.

PubMed

How, A C S; Kumar, R S; Chen, Y-M; Su, D H; Gao, H; Oen, F T; Ho, C-L; Seah, S K; Aung, T

2009-06-01

To compare the intraocular pressure (IOP) lowering efficacy and side effects of latanoprost 0.005% and bimatoprost 0.03% in subjects with chronic primary angle closure glaucoma (PACG). This was an observer-masked randomised crossover study of 60 PACG subjects who received either latanoprost or bimatoprost for 6 weeks, after which they were crossed over to the other medication for another 6 weeks. The IOP-reducing effect of the medications was assessed by the reduction in IOP after 6 weeks of treatment compared with baseline. Fifty-four subjects (80 eyes) completed the study. Latanoprost reduced IOP (mean (SD)) by 8.4 (3.8) mm Hg and bimatoprost by 8.9 (3.9) mm Hg from a baseline of 25.2 (3.6) mm Hg and 25.2 (3.6) mm Hg respectively (p = 0.23). Adverse events were mild in both groups; however there were twice as many reports of an adverse event in the bimatoprost group (81%) compared with the latanoprost group (40%, p<0.01). Ocular irritation was the most frequently reported adverse event in both groups; 22 subjects (37.9%) treated with bimatoprost experienced ocular hyperaemia as compared with 13 subjects (22.4%) treated with latanoprost (p = 0.11). Bimatoprost once daily was similarly effective in reducing IOP compared with latanoprost once daily in subjects with chronic PACG. Both drugs were well tolerated with mild ocular adverse events.
Effect of "preoperative" oral carbohydrate treatment on insulin action--a randomised cross-over unblinded study in healthy subjects.

PubMed

Svanfeldt, Monika; Thorell, Anders; Hausel, Jonatan; Soop, Mattias; Nygren, Jonas; Ljungqvist, Olle

2005-10-01

Preoperative intake of a clear carbohydrate-rich drink reduces insulin resistance after surgery. In this study, we evaluated whether this could be related to increased insulin sensitivity at the onset of surgery. Furthermore, we aimed to establish the optimal dose-regimen. Six healthy volunteers underwent hyperinsulinaemic (0.8 mU/kg/min), normoglycaemic (4.5 mmol/l) clamps and indirect calorimetry on four occasions in a crossover-randomised order; after overnight fasting (CC), after a single evening dose (800 ml) of the drink (LC), after a single morning dose (400 ml, CL) and after intake of the drink in the evening and in the morning before the clamp (LL). Data are presented as mean+/-SD. Statistical analysis was performed using the Student's t-test and ANOVA. Insulin sensitivity was higher in CL and LL (9.2+/-1.5 and 9.3+/-1.9 mg/kg/min, respectively) compared to CC and LC (6.1+/-1.6 and 6.6+/-1.9 mg/kg/min, P<0.01 vs. CL and LL). A carbohydrate-rich drink enhances insulin action 3 h later by approximately 50%. Enhanced insulin action to normal postprandial day-time level at the time of onset of anaesthesia or surgery is likely to, at least partly, explain the effects on postoperative insulin resistance.
Dietary nitrate lowers ambulatory blood pressure in treated, uncontrolled hypertension: a 7-d, double-blind, randomised, placebo-controlled, cross-over trial.

PubMed

Kerley, Conor P; Dolan, Eamon; James, Philip E; Cormican, Liam

2018-03-01

Dietary nitrate has been shown to increase nitrate/nitrite levels and decrease blood pressure (BP) in multiple populations. There are few reports among hypertensives and these reports have provided conflicting evidence. We aimed to assess the effect of daily nitrate compared with placebo in subjects with uncontrolled hypertension (HTN). On day 0, hypertensives wore an ambulatory BP monitor (ABPM) for 24 h and blood was taken. Subjects were then randomised to 7-d nitrate-rich beetroot juice (NO3 -) (12·9 mmol nitrate) followed by 7-d nitrate-depleted beetroot juice (0·5 mmol nitrate) or vice versa. ABPM and blood were assessed before and after both conditions. In all, twenty subjects with treated yet uncontrolled HTN entered and completed the trial (mean age=62·5 years, mean BMI=30·7 kg/m2). Baseline BP was 137/80 (sd 7/7) mmHg. Dietary nitrate was well tolerated and resulted in significantly increased plasma nitrite (P=0·0004) and decreased 24-h systolic BP and diastolic BP compared with placebo (-8 mmHg; P=0·012 and -4 mmHg; P=0·018, respectively). Our results support the existing data suggesting an anti-hypertensive effect of dietary nitrate in treated yet uncontrolled hypertensives. Targeted dietary strategies appear promising contributors to BP control.
Performance differences when using 26- and 29-inch-wheel bikes in Swiss National Team cross-country mountain bikers.

PubMed

Steiner, Thomas; Müller, Beat; Maier, Thomas; Wehrlin, Jon Peter

2016-08-01

The purpose of this study was to analyse the effect of bike type - the 26-inch-wheel bike (26" bike) and the 29-inch-wheel bike (29" bike) - on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26" bike and three trials on a 29" bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29" bike (section A) or the 26" bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes' experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29" bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29" bike as better for performance in general, passing obstacles and traction. The 29" bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26" bike.
Effect of baffle spacing and baffle cut on thermal-hydraulic characteristics of the fluid flow

NASA Astrophysics Data System (ADS)

Chernyateva, R. R.

2018-01-01

This article presents the results of investigations of the influence of baffle spacing and baffle cut on the size of dead zone formed near the cross baffles using numerical simulation methods. It is showed the structure of an additional baffle plate which can be used to reduce the dead zone and smoother flow distribution over the cross section.
The citation of relevant systematic reviews and randomised trials in published reports of trial protocols.

PubMed

Pandis, Nikolaos; Fleming, Padhraig S; Koletsi, Despina; Hopewell, Sally

2016-12-07

It is important that planned randomised trials are justified and placed in the context of the available evidence. The SPIRIT guidelines for reporting clinical trial protocols recommend that a recent and relevant systematic review should be included. The aim of this study was to assess the use of the existing evidence in order to justify trial conduct. Protocols of randomised trials published over a 1-month period (December 2015) indexed in PubMed were obtained. Data on trial characteristics relating to location, design, funding, conflict of interest and type of evidence included for trial justification was extracted in duplicate and independently by two investigators. The frequency of citation of previous research including relevant systematic reviews and randomised trials was assessed. Overall, 101 protocols for RCTs were identified. Most proposed trials were parallel-group (n = 74; 73.3%). Reference to an earlier systematic review with additional randomised trials was found in 9.9% (n = 10) of protocols and without additional trials in 30.7% (n = 31), while reference was made to randomised trials in isolation in 21.8% (n = 22). Explicit justification for the proposed randomised trial on the basis of being the first to address the research question was made in 17.8% (n = 18) of protocols. A randomised controlled trial was not cited in 10.9% (95% CI: 5.6, 18.7) (n = 11), while in 8.9% (95% CI: 4.2, 16.2) (n = 9) of the protocols a systematic review was cited but did not inform trial design. A relatively high percentage of protocols of randomised trials involves prior citation of randomised trials, systematic reviews or both. However, improvements are required to ensure that it is explicit that clinical trials are justified and shaped by contemporary best evidence.
Bayesian Population Genomic Inference of Crossing Over and Gene Conversion

PubMed Central

Padhukasahasram, Badri; Rannala, Bruce

2011-01-01

Meiotic recombination is a fundamental cellular mechanism in sexually reproducing organisms and its different forms, crossing over and gene conversion both play an important role in shaping genetic variation in populations. Here, we describe a coalescent-based full-likelihood Markov chain Monte Carlo (MCMC) method for jointly estimating the crossing-over, gene-conversion, and mean tract length parameters from population genomic data under a Bayesian framework. Although computationally more expensive than methods that use approximate likelihoods, the relative efficiency of our method is expected to be optimal in theory. Furthermore, it is also possible to obtain a posterior sample of genealogies for the data using this method. We first check the performance of the new method on simulated data and verify its correctness. We also extend the method for inference under models with variable gene-conversion and crossing-over rates and demonstrate its ability to identify recombination hotspots. Then, we apply the method to two empirical data sets that were sequenced in the telomeric regions of the X chromosome of Drosophila melanogaster. Our results indicate that gene conversion occurs more frequently than crossing over in the su-w and su-s gene sequences while the local rates of crossing over as inferred by our program are not low. The mean tract lengths for gene-conversion events are estimated to be ∼70 bp and 430 bp, respectively, for these data sets. Finally, we discuss ideas and optimizations for reducing the execution time of our algorithm. PMID:21840857
Impact of online education on intern behaviour around Joint Commission National Patient Safety Goals: A randomised trial

PubMed Central

TJ, Shaw; LIM, Pernar; SE, Peyre; JF, Helfrick; K, Vogelgesang; E, Graydon-Baker; Y, Chretien; EJ, Brown; J, Nicholson; JJ, Heit; JP, Co; TK, Gandhi

2014-01-01

Purpose To compare the effectiveness of 2 types of online learning methodologies for improving the patient-safety behaviours mandated in the Joint Commission National Patient Safety Goals (NPSG). Methods This randomized controlled trial was conducted in 2010 at Massachusetts General Hospital (MGH) and Brigham & Women’s Hospital (BWH) in Boston USA. Incoming interns were randomised to either receive an online Spaced Education program (SE) consisting of cases and questions that reinforce over time, or a program consisting of an online slide show followed by a quiz (SQ). The outcome measures included NPSG-knowledge improvement, NPSG-compliant behaviors in a simulation scenario, self reported confidence in safety and quality, program acceptability and program relevance. Results Both online learning programs improved knowledge retention. On four out of seven survey items measuring satisfaction and self reported confidence, the proportion of SE interns responding positively was significantly higher (p<0.05) than the fraction of SQ interns. SE interns demonstrated a mean 4.79 (36.6%) NPSG-compliant behaviors (out of 13 total), while SQ interns completed a mean 4.17 (32.0%) (p=0.09). Among those in surgical fields, SE interns demonstrated a mean 5.67 (43.6%) NPSG-compliant behaviors, while SQ interns completed a mean 2.33 (17.9%) (p=0.015). Focus group data indicates that SE was more contextually relevant than SQ and significantly more engaging. Conclusion While both online methodologies improved knowledge surrounding the NPSG, SE was more contextually relevant to trainees and engaging. SE impacted more significantly on both self reported confidence and the behaviour of surgical residents in a simulated scenario. PMID:22706930
A double-blind, placebo-controlled, cross-over study to establish the bifidogenic effect of a very-long-chain inulin extracted from globe artichoke (Cynara scolymus) in healthy human subjects.

PubMed

Costabile, Adele; Kolida, Sofia; Klinder, Annett; Gietl, Eva; Bäuerlein, Michael; Frohberg, Claus; Landschütze, Volker; Gibson, Glenn R

2010-10-01

There is growing interest in the use of inulins as substrates for the selective growth of beneficial gut bacteria such as bifidobacteria and lactobacilli because recent studies have established that their prebiotic effect is linked to several health benefits. In the present study, the impact of a very-long-chain inulin (VLCI), derived from globe artichoke (Cynara scolymus), on the human intestinal microbiota compared with maltodextrin was determined. A double-blind, cross-over study was carried out in thirty-two healthy adults who were randomised into two groups and consumed 10 g/d of either VLCI or maltodextrin, for two 3-week study periods, separated by a 3-week washout period. Numbers of faecal bifidobacteria and lactobacilli were significantly higher upon VLCI ingestion compared with the placebo. Additionally, levels of Atopobium group significantly increased, while Bacteroides-Prevotella numbers were significantly reduced. No significant changes in faecal SCFA concentrations were observed. There were no adverse gastrointestinal symptoms apart from a significant increase in mild and moderate bloating upon VLCI ingestion. These observations were also confirmed by in vitro gas production measurements. In conclusion, daily consumption of VLCI extracted from globe artichoke exerted a pronounced prebiotic effect on the human faecal microbiota composition and was well tolerated by all volunteers.

The simulated early learning of cervical spine manipulation technique utilising mannequins.

PubMed

Chapman, Peter D; Stomski, Norman J; Losco, Barrett; Walker, Bruce F

2015-01-01

Trivial pain or minor soreness commonly follows neck manipulation and has been estimated at one in three treatments. In addition, rare catastrophic events can occur. Some of these incidents have been ascribed to poor technique where the neck is rotated too far. The aims of this study were to design an instrument to measure competency of neck manipulation in beginning students when using a simulation mannequin, and then examine the suitability of using a simulation mannequin to teach the early psychomotor skills for neck chiropractic manipulative therapy. We developed an initial set of questionnaire items and then used an expert panel to assess an instrument for neck manipulation competency among chiropractic students. The study sample comprised all 41 fourth year 2014 chiropractic students at Murdoch University. Students were randomly allocated into either a usual learning or mannequin group. All participants crossed over to undertake the alternative learning method after four weeks. A chi-square test was used to examine differences between groups in the proportion of students achieving an overall pass mark at baseline, four weeks, and eight weeks. This study was conducted between January and March 2014. We successfully developed an instrument of measurement to assess neck manipulation competency in chiropractic students. We then randomised 41 participants to first undertake either "usual learning" (n = 19) or "mannequin learning" (n = 22) for early neck manipulation training. There were no significant differences between groups in the overall pass rate at baseline (χ(2) = 0.10, p = 0.75), four weeks (χ(2) = 0.40, p = 0.53), and eight weeks (χ(2) = 0.07, p = 0.79). This study demonstrates that the use of a mannequin does not affect the manipulation competency grades of early learning students at short term follow up. Our findings have potentially important safety implications as the results indicate that students could initially gain competence in neck manipulation by using mannequins before proceeding to perform neck manipulation on each other.
Plant-rich mixed meals based on Palaeolithic diet principles have a dramatic impact on incretin, peptide YY and satiety response, but show little effect on glucose and insulin homeostasis: an acute-effects randomised study.

PubMed

Bligh, H Frances J; Godsland, Ian F; Frost, Gary; Hunter, Karl J; Murray, Peter; MacAulay, Katrina; Hyliands, Della; Talbot, Duncan C S; Casey, John; Mulder, Theo P J; Berry, Mark J

2015-02-28

There is evidence for health benefits from 'Palaeolithic' diets; however, there are a few data on the acute effects of rationally designed Palaeolithic-type meals. In the present study, we used Palaeolithic diet principles to construct meals comprising readily available ingredients: fish and a variety of plants, selected to be rich in fibre and phyto-nutrients. We investigated the acute effects of two Palaeolithic-type meals (PAL 1 and PAL 2) and a reference meal based on WHO guidelines (REF), on blood glucose control, gut hormone responses and appetite regulation. Using a randomised cross-over trial design, healthy subjects were given three meals on separate occasions. PAL2 and REF were matched for energy, protein, fat and carbohydrates; PAL1 contained more protein and energy. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) concentrations were measured over a period of 180 min. Satiation was assessed using electronic visual analogue scale (EVAS) scores. GLP-1 and PYY concentrations were significantly increased across 180 min for both PAL1 (P= 0·001 and P< 0·001) and PAL2 (P= 0·011 and P= 0·003) compared with the REF. Concomitant EVAS scores showed increased satiety. By contrast, GIP concentration was significantly suppressed. Positive incremental AUC over 120 min for glucose and insulin did not differ between the meals. Consumption of meals based on Palaeolithic diet principles resulted in significant increases in incretin and anorectic gut hormones and increased perceived satiety. Surprisingly, this was independent of the energy or protein content of the meal and therefore suggests potential benefits for reduced risk of obesity.
Butyrylated starch intake can prevent red meat-induced O6-methyl-2-deoxyguanosine adducts in human rectal tissue: a randomised clinical trial.

PubMed

Le Leu, Richard K; Winter, Jean M; Christophersen, Claus T; Young, Graeme P; Humphreys, Karen J; Hu, Ying; Gratz, Silvia W; Miller, Rosalind B; Topping, David L; Bird, Anthony R; Conlon, Michael A

2015-07-01

Epidemiological studies have identified increased colorectal cancer (CRC) risk with high red meat (HRM) intakes, whereas dietary fibre intake appears to be protective. In the present study, we examined whether a HRM diet increased rectal O(6)-methyl-2-deoxyguanosine (O(6)MeG) adduct levels in healthy human subjects, and whether butyrylated high-amylose maize starch (HAMSB) was protective. A group of twenty-three individuals consumed 300 g/d of cooked red meat without (HRM diet) or with 40 g/d of HAMSB (HRM+HAMSB diet) over 4-week periods separated by a 4-week washout in a randomised cross-over design. Stool and rectal biopsy samples were collected for biochemical, microbial and immunohistochemical analyses at baseline and at the end of each 4-week intervention period. The HRM diet increased rectal O(6)MeG adducts relative to its baseline by 21% (P < 0.01), whereas the addition of HAMSB to the HRM diet prevented this increase. Epithelial proliferation increased with both the HRM (P < 0.001) and HRM + HAMSB (P < 0.05) diets when compared with their respective baseline levels, but was lower following the HRM + HAMSB diet compared with the HRM diet (P < 0.05). Relative to its baseline, the HRM + HAMSB diet increased the excretion of SCFA by over 20% (P < 0.05) and increased the absolute abundances of the Clostridium coccoides group (P < 0.05), the Clostridium leptum group (P < 0.05), Lactobacillus spp. (P < 0.01), Parabacteroides distasonis (P < 0.001) and Ruminococcus bromii (P < 0.05), but lowered Ruminococcus torques (P < 0.05) and the proportions of Ruminococcus gnavus, Ruminococcus torques and Escherichia coli (P < 0.01). HRM consumption could increase the risk of CRC through increased formation of colorectal epithelial O(6)MeG adducts. HAMSB consumption prevented red meat-induced adduct formation, which may be associated with increased stool SCFA levels and/or changes in the microbiota composition.
FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): protocol for a multicentre randomised feasibility trial of non-invasive respiratory support in critically ill children.

PubMed

Ramnarayan, Padmanabhan; Lister, Paula; Dominguez, Troy; Habibi, Parviz; Edmonds, Naomi; Canter, Ruth; Mouncey, Paul; Peters, Mark J

2017-06-12

Over 18 000 children are admitted annually to UK paediatric intensive care units (PICUs), of whom nearly 75% receive respiratory support (invasive and/or non-invasive). Continuous positive airway pressure (CPAP) has traditionally been used to provide first-line non-invasive respiratory support (NRS) in PICUs; however, high-flow nasal cannula therapy (HFNC), a novel mode of NRS, has recently gained popularity despite the lack of high-quality trial evidence to support its effectiveness. This feasibility study aims to inform the design and conduct of a future definitive randomised clinical trial (RCT) comparing the two modes of respiratory support. We will conduct a three-centre randomised feasibility study over 12 months. Patients admitted to participating PICUs who satisfy eligibility criteria will be recruited to either group A (primary respiratory failure) or group B (postextubation). Consent will be obtained from parents/guardians prior to randomisation in 'planned' group B, and deferred in emergency situations (group A and 'rescue' group B). Participants will be randomised (1:1) to either CPAP or HFNC using sealed, opaque envelopes, from a computer-generated randomisation sequence with variable block sizes. The study protocol specifies algorithms for the initiation, maintenance and weaning of HFNC and CPAP. The primary outcomes are related to feasibility, including the number of eligible patients in each group, feasibility of randomising >50% of eligible patients and measures of adherence to the treatment protocols. Data will also be collected on patient outcomes (eg, mortality and length of PICU stay) to inform the selection of an appropriate outcome measure in a future RCT. We aim to recruit 120 patients to the study. Ethical approval was granted by the National Research Ethics Service Committee North East-Tyne&Wear South (15/NE/0296). Study findings will be disseminated through peer-reviewed journals, national and international conferences. NCT02612415; pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Can Healthcare Assistant Training (CHAT) improve the relational care of older people? Study protocol for a pilot cluster randomised controlled trial.

PubMed

Arthur, Antony; Maben, Jill; Wharrad, Heather; Aldus, Clare; Sarre, Sophie; Schneider, Justine; Nicholson, Caroline; Barton, Garry; Cox, Karen; Clark, Allan

2015-12-09

People aged 75 years and over account for 1 in 4 of all hospital admissions. There has been increasing recognition of problems in the care of older people, particularly in hospitals. Evidence suggests that older people judge the care they receive in terms of kindness, empathy, compassion, respectful communication and being seen as a person not just a patient. These are aspects of care to which we refer when we use the term 'relational care'. Healthcare assistants deliver an increasing proportion of direct care to older people, yet their training needs are often overlooked. This study will determine the acceptability and feasibility of a cluster randomised controlled trial of 'Older People's Shoes' a 2-day training intervention for healthcare assistants caring for older people in hospital. Within this pilot, 2-arm, parallel, cluster randomised controlled trial, healthcare assistants within acute hospital wards are randomised to either the 2-day training intervention or training as usual. Registered nurses deliver 'Older People's Shoes' over 2 days, approximately 1 week apart. It contains three components: experiential learning about ageing, exploration of older people's stories, and customer care. Outcomes will be measured at the level of patient (experience of emotional care and quality of life during their hospital stay), healthcare assistant (empathy and attitudes towards older people), and ward (quality of staff/patient interaction). Semi-structured interviews of a purposive sample of healthcare assistants receiving the intervention, and all trainers delivering the intervention, will be undertaken to gain insights into the experiences of both the intervention and the trial, and its perceived impact on practice. Few training interventions for care staff have been rigorously tested using randomised designs. This study will establish the viability of a definitive cluster randomised controlled trial of a new training intervention to improve the relational care proided by healthcare assistants working with older people in hospital. The study was registered as an International Standard Randomised Controlled Trial ( ISRCTN10385799 ) on 29 December 2014.
FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): protocol for a multicentre randomised feasibility trial of non-invasive respiratory support in critically ill children

PubMed Central

Ramnarayan, Padmanabhan; Lister, Paula; Dominguez, Troy; Habibi, Parviz; Edmonds, Naomi; Canter, Ruth; Mouncey, Paul; Peters, Mark J

2017-01-01

Introduction Over 18 000 children are admitted annually to UK paediatric intensive care units (PICUs), of whom nearly 75% receive respiratory support (invasive and/or non-invasive). Continuous positive airway pressure (CPAP) has traditionally been used to provide first-line non-invasive respiratory support (NRS) in PICUs; however, high-flow nasal cannula therapy (HFNC), a novel mode of NRS, has recently gained popularity despite the lack of high-quality trial evidence to support its effectiveness. This feasibility study aims to inform the design and conduct of a future definitive randomised clinical trial (RCT) comparing the two modes of respiratory support. Methods and analysis We will conduct a three-centre randomised feasibility study over 12 months. Patients admitted to participating PICUs who satisfy eligibility criteria will be recruited to either group A (primary respiratory failure) or group B (postextubation). Consent will be obtained from parents/guardians prior to randomisation in ‘planned’ group B, and deferred in emergency situations (group A and ‘rescue’ group B). Participants will be randomised (1:1) to either CPAP or HFNC using sealed, opaque envelopes, from a computer-generated randomisation sequence with variable block sizes. The study protocol specifies algorithms for the initiation, maintenance and weaning of HFNC and CPAP. The primary outcomes are related to feasibility, including the number of eligible patients in each group, feasibility of randomising >50% of eligible patients and measures of adherence to the treatment protocols. Data will also be collected on patient outcomes (eg, mortality and length of PICU stay) to inform the selection of an appropriate outcome measure in a future RCT. We aim to recruit 120 patients to the study. Ethics and dissemination Ethical approval was granted by the National Research Ethics Service Committee North East—Tyne&Wear South (15/NE/0296). Study findings will be disseminated through peer-reviewed journals, national and international conferences. Trials registration number NCT02612415; pre-results. PMID:28606907
Conformational dynamics of Peb4 exhibit "mother's arms" chain model: a molecular dynamics study.

PubMed

Dantu, Sarath Chandra; Khavnekar, Sagar; Kale, Avinash

2017-08-01

Peb4 from Campylobacter jejuni is an intertwined dimeric, periplasmic holdase, which also exhibits peptidyl prolyl cis/trans isomerase (PPIase) activity. Peb4 gene deletion alters the outer membrane protein profile and impairs cellular adhesion and biofilm formation for C. jejuni. Earlier crystallographic study has proposed that the PPIase domains are flexible and might form a cradle for holding the substrate and these aspects of Peb4 were explored using sub-microsecond molecular dynamics simulations in solution environment. Our simulations have revealed that PPIase domains are highly flexible and undergo a large structural change where they move apart from each other by 8 nm starting at .5 nm. Further, this large conformational change renders Peb4 as a compact protein with crossed-over conformation, forms a central cavity, which can "cradle" the target substrate. As reported for other chaperone proteins, flexibility of linker region connecting the chaperone and PPIase domains is key to forming the "crossed-over" conformation. The conformational transition of the Peb4 protein from the X-ray structure to the crossed-over conformation follows the "mother's arms" chain model proposed for the FkpA chaperone protein. Our results offer insights into how Peb4 and similar chaperones can use the conformational heterogeneity at their disposal to perform its much-revered biological function.
Pilot study comparing simulation-based and didactic lecture-based critical care teaching for final-year medical students.

PubMed

Solymos, Orsolya; O'Kelly, Patrick; Walshe, Criona M

2015-10-21

Simulation-based medical education has rapidly evolved over the past two decades, despite this, there are few published reports of its use in critical care teaching. We hypothesised that simulation-based teaching of a critical care topic to final-year medical students is superior to lecture-based teaching. Thirty-nine final-year medical students were randomly assigned to either simulation-based or lecture-based teaching in the chosen critical care topic. The study was conducted over a 6-week period. Efficacy of each teaching method was compared through use of multiple choice questionnaires (MCQ) - baseline, post-teaching and 2 week follow-up. Student satisfaction was evaluated by means of a questionnaire. Feasibility and resource requirements were documented by teachers. Eighteen students were randomised to simulation-based, and 21 to lecture-based teaching. There were no differences in age and gender between groups (p > 0.05). Simulation proved more resource intensive requiring specialised equipment, two instructors, and increased duration of teaching sessions (126.7 min (SD = 4.71) vs 68.3 min (SD = 2.36)). Students ranked simulation-based teaching higher with regard to enjoyment (p = 0.0044), interest (p = 0.0068), relevance to taught subject (p = 0.0313), ease of understanding (p = 0.0476) and accessibility to posing questions (p = 0.001). Both groups demonstrated improvement in post-teaching MCQ from baseline (p = 0.0002), with greater improvement seen among the simulation group (p = 0.0387), however, baseline scores were higher among the lecture group. The results of the 2-week follow-up MCQ and post-teaching MCQ were not statistically significant when each modality were compared. Simulation was perceived as more enjoyable by students. Although there was a greater improvement in post-teaching MCQ among the simulator group, baseline scores were higher among lecture group which limits interpretation of efficacy. Simulation is more resource intensive, as demonstrated by increased duration and personnel required, and this may have affected our results. The current pilot may be of use in informing future studies in this area.
Designing an upgrade of the Medley setup for light-ion production and fission cross-section measurements

NASA Astrophysics Data System (ADS)

Jansson, K.; Gustavsson, C.; Al-Adili, A.; Hjalmarsson, A.; Andersson-Sundén, E.; Prokofiev, A. V.; Tarrío, D.; Pomp, S.

2015-09-01

Measurements of neutron-induced fission cross-sections and light-ion production are planned in the energy range 1-40 MeV at the upcoming Neutrons For Science (NFS) facility. In order to prepare our detector setup for the neutron beam with continuous energy spectrum, a simulation software was written using the Geant4 toolkit for both measurement situations. The neutron energy range around 20 MeV is troublesome when it comes to the cross-sections used by Geant4 since data-driven cross-sections are only available below 20 MeV but not above, where they are based on semi-empirical models. Several customisations were made to the standard classes in Geant4 in order to produce consistent results over the whole simulated energy range. Expected uncertainties are reported for both types of measurements. The simulations have shown that a simultaneous precision measurement of the three standard cross-sections H(n,n), 235U(n,f) and 238U(n,f) relative to each other is feasible using a triple layered target. As high resolution timing detectors for fission fragments we plan to use Parallel Plate Avalanche Counters (PPACs). The simulation results have put some restrictions on the design of these detectors as well as on the target design. This study suggests a fissile target no thicker than 2 μm (1.7 mg/cm2) and a PPAC foil thickness preferably less than 1 μm. We also comment on the usability of Geant4 for simulation studies of neutron reactions in this energy range.
Natural convection enhancement by a discrete vibrating plate and a cross-flow opening: a numerical investigation

NASA Astrophysics Data System (ADS)

Florio, L. A.; Harnoy, A.

2011-06-01

In this study, a unique combination of a vibrating plate and a cross-flow passage is proposed as a means of enhancing natural convection cooling. The enhancement potential was estimated based on numerical studies involving a representative model which includes a short, transversely oscillating plate, placed over a transverse cross-flow opening in a uniformly heated vertical channel wall dividing two adjacent vertical channels. The resulting velocity and temperature fields are analyzed, with the focus on the local thermal effects near the opening. The simulation indicates up to a 50% enhancement in the local heat transfer coefficient for vibrating plate amplitudes of at least 30% of the mean clearance space and frequencies of over 82 rad/s.
Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial.

PubMed

Hollands, Kristen L; Pelton, Trudy A; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M; Wing, Alan M; Tyson, Sarah F; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M

2015-01-01

Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services. Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments. Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Clinicaltrials.gov NCT01600391.
Factors Influencing Practical Training Quality in Iranian Agricultural Higher Education

ERIC Educational Resources Information Center

Mojarradi, Gholamreza; Karamidehkordi, Esmail

2016-01-01

This paper presents an analysis of the factors influencing the practical training quality of agricultural higher education programmes from the senior students' perspective. The study was conducted in two public universities located in the north-west of Iran using a cross-sectional survey and structured interviews with a randomised sample of 254…
A multinational randomised study comparing didactic lectures with case scenario in a severe sepsis medical simulation course.

PubMed

Li, Chih-Huang; Kuan, Win-Sen; Mahadevan, Malcolm; Daniel-Underwood, Lynda; Chiu, Te-Fa; Nguyen, H Bryant

2012-07-01

Medical simulation has been used to teach critical illness in a variety of settings. This study examined the effect of didactic lectures compared with simulated case scenario in a medical simulation course on the early management of severe sepsis. A prospective multicentre randomised study was performed enrolling resident physicians in emergency medicine from four hospitals in Asia. Participants were randomly assigned to a course that included didactic lectures followed by a skills workshop and simulated case scenario (lecture-first) or to a course that included a skills workshop and simulated case scenario followed by didactic lectures (simulation-first). A pre-test was given to the participants at the beginning of the course, post-test 1 was given after the didactic lectures or simulated case scenario depending on the study group assignment, then a final post-test 2 was given at the end of the course. Performance on the simulated case scenario was evaluated with a performance task checklist. 98 participants were enrolled in the study. Post-test 2 scores were significantly higher than pre-test scores in all participants (80.8 ± 12.0% vs 65.4 ± 12.2%, p<0.01). There was no difference in pre-test scores between the two study groups. The lecture-first group had significantly higher post-test 1 scores than the simulation-first group (78.8 ± 10.6% vs 71.6 ± 12.6%, p<0.01). There was no difference in post-test 2 scores between the two groups. The simulated case scenario task performance completion was 90.8% (95% CI 86.6% to 95.0%) in the lecture-first group compared with 83.8% (95% CI 79.5% to 88.1%) in the simulation-first group (p=0.02). A medical simulation course can improve resident physician knowledge in the early management of severe sepsis. Such a course should include a comprehensive curriculum that includes didactic lectures followed by simulation experience.
Postprandial lipid responses do not differ following consumption of butter or vegetable oil when consumed with omega-3 polyunsaturated fatty acids.

PubMed

Dias, Cintia B; Phang, Melinda; Wood, Lisa G; Garg, Manohar L

2015-04-01

Dietary saturated fat (SFA) intake has been associated with elevated blood lipid levels and increased risk for the development of chronic diseases. However, some animal studies have demonstrated that dietary SFA may not raise blood lipid levels when the diet is sufficient in omega-3 polyunsaturated fatty acids (n-3PUFA). Therefore, in a randomised cross-over design, we investigated the postprandial effects of feeding meals rich in either SFA (butter) or vegetable oil rich in omega-6 polyunsaturated fatty acids (n-6PUFA), in conjunction with n-3PUFA, on blood lipid profiles [total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triacylglycerol (TAG)] and n-3PUFA incorporation into plasma lipids over a 6-h period. The incremental area under the curve for plasma cholesterol, LDL-C, HDL-C, TAG and n-3PUFA levels over 6 h was similar in the n-6PUFA compared to SFA group. The postprandial lipemic response to saturated fat is comparable to that of n-6PUFA when consumed with n-3PUFA; however, sex-differences in response to dietary fat type are worthy of further attention.
Microstructurally Based Cross-slip Mechanisms and Their Effects on Dislocation Microstructure Evolution in fcc Crystals

DTIC Science & Technology

2015-01-01

still necessary. One such model that could bridge this gap is discrete dis- location dynamics ( DDD ) simulations, in which both the time- and length-scale...limitations from atomic simulations are greatly reduced. Over the past two decades, two-dimen- sional (2D) and three-dimensional (3D) DDD methods have...dislocation ensem- bles according to physics-based rules [27–34]. The physics that can be incorporated in DDD simulations can range http://dx.doi.org
Modular Aquatic Simulation System 1D

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-04-19

MASS1 simulates open channel hydrodynamics and transport in branched channel networks, using cross-section averaged forms of the continuity, momentum, and convection diffusion equations. Thermal energy transport (temperature), including meteorological influences is supported. The thermodynamics of total dissolved gas (TDG) can be directly simulated. MASS1 has been developed over the last 20 years. It is currently being used on DOE projects that require MASS1 to beopen source. Hence, the authors would like to distribute MASS1 in source form.
Acceptability of different oral formulations in infants and preschool children

PubMed Central

van Riet-Nales, Diana A; de Neef, Barbara J; Schobben, Alfred F A M; Ferreira, José A; Egberts, Toine C G; Rademaker, Catharine M A

2013-01-01

Objective Liquid medicines are easy to swallow. However, they may have disadvantages, such as a bad taste or refrigerated storage conditions. These disadvantages may be avoided by the use of oral solid medicines, such as powders or tablets. The aim of this study was to investigate the acceptability of and preference among four oral formulations in domiciliary infants and preschool children in The Netherlands. Methods Parents administered four oral placebo dosage forms that were aimed at a neutral taste, at home, to their child (1–4 years of age) twice on one day following a randomised cross-over design: small (4 mm) tablet, powder, suspension and syrup. They were asked to report the child's acceptability by a score on a 10 cm visual analogue scale (VAS score) and by the result of the intake. At the end of the study, they were asked to report the preference of the child and themselves. Results 183 children were included and 148 children were evaluated. The data revealed a period/cross-over effect. The estimate of the mean VAS score was significantly higher for the tablet than for the suspension (tablet 9.39/9.01; powder 8.84/8.20, suspension 8.26/7.90, syrup 8.35/8.19; data day 1/all days). The estimate of the mean number of intakes fully swallowed was significantly higher for the tablet than for the other formulations (all p values <0.05). Children and parents preferred the tablet and syrup over the suspension and the suspension over the powder (all p values <0.05). Conclusions All formulations were well accepted. The tablets were the best accepted formulation; the tablets and syrup the most preferred. Trial Registration number ISRCTN63138435. PMID:23853004
Effects of cross-bridge compliance on the force-velocity relationship and muscle power output

PubMed Central

Fenwick, Axel J.; Wood, Alexander M.

2017-01-01

Muscles produce force and power by utilizing chemical energy through ATP hydrolysis. During concentric contractions (shortening), muscles generate less force compared to isometric contractions, but consume greater amounts of energy as shortening velocity increases. Conversely, more force is generated and less energy is consumed during eccentric muscle contractions (lengthening). This relationship between force, energy use, and the velocity of contraction has important implications for understanding muscle efficiency, but the molecular mechanisms underlying this behavior remain poorly understood. Here we used spatially-explicit, multi-filament models of Ca2+-regulated force production within a half-sarcomere to simulate how force production, energy utilization, and the number of bound cross-bridges are affected by dynamic changes in sarcomere length. These computational simulations show that cross-bridge binding increased during slow-velocity concentric and eccentric contractions, compared to isometric contractions. Over the full ranges of velocities that we simulated, cross-bridge cycling and energy utilization (i.e. ATPase rates) increased during shortening, and decreased during lengthening. These findings are consistent with the Fenn effect, but arise from a complicated relationship between velocity-dependent cross-bridge recruitment and cross-bridge cycling kinetics. We also investigated how force production, power output, and energy utilization varied with cross-bridge and myofilament compliance, which is impossible to address under typical experimental conditions. These important simulations show that increasing cross-bridge compliance resulted in greater cross-bridge binding and ATPase activity, but less force was generated per cross-bridge and throughout the sarcomere. These data indicate that the efficiency of force production decreases in a velocity-dependent manner, and that this behavior is sensitive to cross-bridge compliance. In contrast, significant effects of myofilament compliance on force production were only observed during isometric contractions, suggesting that changes in myofilament compliance may not influence power output during non-isometric contractions as greatly as changes in cross-bridge compliance. These findings advance our understanding of how cross-bridge and myofilament properties underlie velocity-dependent changes in contractile efficiency during muscle movement. PMID:29284062
Effects of cross-bridge compliance on the force-velocity relationship and muscle power output.

PubMed

Fenwick, Axel J; Wood, Alexander M; Tanner, Bertrand C W

2017-01-01

Muscles produce force and power by utilizing chemical energy through ATP hydrolysis. During concentric contractions (shortening), muscles generate less force compared to isometric contractions, but consume greater amounts of energy as shortening velocity increases. Conversely, more force is generated and less energy is consumed during eccentric muscle contractions (lengthening). This relationship between force, energy use, and the velocity of contraction has important implications for understanding muscle efficiency, but the molecular mechanisms underlying this behavior remain poorly understood. Here we used spatially-explicit, multi-filament models of Ca2+-regulated force production within a half-sarcomere to simulate how force production, energy utilization, and the number of bound cross-bridges are affected by dynamic changes in sarcomere length. These computational simulations show that cross-bridge binding increased during slow-velocity concentric and eccentric contractions, compared to isometric contractions. Over the full ranges of velocities that we simulated, cross-bridge cycling and energy utilization (i.e. ATPase rates) increased during shortening, and decreased during lengthening. These findings are consistent with the Fenn effect, but arise from a complicated relationship between velocity-dependent cross-bridge recruitment and cross-bridge cycling kinetics. We also investigated how force production, power output, and energy utilization varied with cross-bridge and myofilament compliance, which is impossible to address under typical experimental conditions. These important simulations show that increasing cross-bridge compliance resulted in greater cross-bridge binding and ATPase activity, but less force was generated per cross-bridge and throughout the sarcomere. These data indicate that the efficiency of force production decreases in a velocity-dependent manner, and that this behavior is sensitive to cross-bridge compliance. In contrast, significant effects of myofilament compliance on force production were only observed during isometric contractions, suggesting that changes in myofilament compliance may not influence power output during non-isometric contractions as greatly as changes in cross-bridge compliance. These findings advance our understanding of how cross-bridge and myofilament properties underlie velocity-dependent changes in contractile efficiency during muscle movement.
The NAtional randomised controlled Trial of Tonsillectomy IN Adults (NATTINA): a clinical and cost-effectiveness study: study protocol for a randomised control trial.

PubMed

Rubie, Isabel; Haighton, Catherine; O'Hara, James; Rousseau, Nikki; Steen, Nick; Stocken, Deborah D; Sullivan, Frank; Vale, Luke; Wilkes, Scott; Wilson, Janet

2015-06-06

The role of tonsillectomy in the management of adult tonsillitis remains uncertain and UK regional variation in tonsillectomy rates persists. Patients, doctors and health policy makers wish to know the costs and benefits of tonsillectomy against conservative management and whether therapy can be better targeted to maximise benefits and minimise risks of surgery, hence maximising cost-effective use of resources. NATTINA incorporates the first attempt to map current NHS referral criteria against other metrics of tonsil disease severity. A UK multi-centre, randomised, controlled trial for adults with recurrent tonsillitis to compare the clinical and cost-effectiveness of tonsillectomy versus conservative management. An initial feasibility study comprises qualitative interviews to investigate the practicality of the protocol, including willingness to randomise and be randomised. Approximately 20 otolaryngology staff, 10 GPs and 15 ENT patients will be recruited over 5 months in all 9 proposed main trial participating sites. A 6-month internal pilot will then recruit 72 patients across 6 of the 9 sites. Participants will be adults with recurrent acute tonsillitis referred by a GP to secondary care. Randomisation between tonsillectomy and conservative management will be according to a blocked allocation method in a 1:1 ratio stratified by centre and baseline disease severity. If the pilot is successful, the main trial will recruit a further 528 patients over 18 months in all 9 participating sites. All participants will be followed up for a total of 24 months, throughout which both primary and secondary outcome data will be collected. The primary outcome is the number of sore throat days experienced over the 24-month follow-up. The pilot and main trials include an embedded qualitative process evaluation. NATTINA is designed to evaluate the relative effectiveness and efficiency of tonsillectomy versus conservative management in patients with recurrent sore throat who are eligible for surgery. Most adult tonsil disease and surgery has an impact on economically active age groups, with individual and societal costs through loss of earnings and productivity. Avoidance of unnecessary operations and prioritisation of those individuals likely to gain most from tonsillectomy would reduce costs to the NHS and society. ISRCTN55284102, Date of Registration: 4 August 2014.

Obtaining real-world evidence: the Salford Lung Study

PubMed Central

New, John P; Bakerly, Nawar Diar; Leather, David; Woodcock, Ashley

2014-01-01

We need to assess clinical treatments in real-life settings outside of randomised controlled trials (RCTs). Pragmatic RCT (pRCT) data can supplement RCTs by providing effectiveness information to support healthcare decisions. Electronic health records can facilitate concurrent safety monitoring and data collection without direct patient contact for large randomised study populations in pRCTs. The Salford Lung Study is the world's first phase III pRCT in asthma and chronic obstructive pulmonary disease (COPD), which aims to randomise over 7000 patients. This paper describes the hurdles overcome and the enormous effort and resource required to establish this comparative effectiveness study of a prelicence intervention. GlaxoSmithKline protocol HZC115151 Asthma study clinicaltrials.gov registration NCT01706198 COPD study clinicaltrials.gov registration NCT01551758 PMID:24603195
An optimised patient information sheet did not significantly increase recruitment or retention in a falls prevention study: an embedded randomised recruitment trial.

PubMed

Cockayne, Sarah; Fairhurst, Caroline; Adamson, Joy; Hewitt, Catherine; Hull, Robin; Hicks, Kate; Keenan, Anne-Maree; Lamb, Sarah E; Green, Lorraine; McIntosh, Caroline; Menz, Hylton B; Redmond, Anthony C; Rodgers, Sara; Torgerson, David J; Vernon, Wesley; Watson, Judith; Knapp, Peter; Rick, Jo; Bower, Peter; Eldridge, Sandra; Madurasinghe, Vichithranie W; Graffy, Jonathan

2017-03-28

Randomised controlled trials are generally regarded as the 'gold standard' experimental design to determine the effectiveness of an intervention. Unfortunately, many trials either fail to recruit sufficient numbers of participants, or recruitment takes longer than anticipated. The current embedded trial evaluates the effectiveness of optimised patient information sheets on recruitment of participants in a falls prevention trial. A three-arm, embedded randomised methodology trial was conducted within the National Institute for Health Research-funded REducing Falls with ORthoses and a Multifaceted podiatry intervention (REFORM) cohort randomised controlled trial. Routine National Health Service podiatry patients over the age of 65 were randomised to receive either the control patient information sheet (PIS) for the host trial or one of two optimised versions, a bespoke user-tested PIS or a template-developed PIS. The primary outcome was the proportion of patients in each group who went on to be randomised to the host trial. Six thousand and nine hundred patients were randomised 1:1:1 into the embedded trial. A total of 193 (2.8%) went on to be randomised into the main REFORM trial (control n = 62, template-developed n = 68; bespoke user-tested n = 63). Information sheet allocation did not improve recruitment to the trial (odds ratios for the three pairwise comparisons: template vs control 1.10 (95% CI 0.77-1.56, p = 0.60); user-tested vs control 1.01 (95% CI 0.71-1.45, p = 0.94); and user-tested vs template 0.92 (95% CI 0.65-1.31, p = 0.65)). This embedded methodology trial has demonstrated limited evidence as to the benefit of using optimised information materials on recruitment and retention rates in the REFORM study. International Standard Randomised Controlled Trials Number registry, ISRCTN68240461 . Registered on 01 July 2011.
Interventions to increase immunisation coverage among children 12–23 months of age in India through participatory learning and community engagement: pilot study for a cluster randomised trial

PubMed Central

Johri, Mira; Chandra, Dinesh; Koné, Georges K; Dudeja, Sakshi; Sylvestre, Marie-Pierre; Sharma, Jitendar K; Pahwa, Smriti

2015-01-01

Objective With the aim of conducting a future cluster randomised trial to assess intervention impact on child vaccination coverage, we designed a pilot study to assess feasibility and aid in refining methods for the larger study. Trial design Cluster-randomised design with a 1:1 allocation ratio. Methods Clusters were 12 villages in rural Uttar Pradesh. All women residing in a selected village who were mothers of a child 0–23 months of age were eligible; participants were chosen at random. Over 4 months, intervention group (IG) villages received: (1) home visits by volunteers; (2) community mobilisation events to promote immunisation. Control group (CG) villages received community mobilisation to promote nutrition. A toll-free number for immunisation was offered to all IG and CG village residents. Primary outcomes were ex-ante criteria for feasibility of the main study related to processes for recruitment and randomisation (50% of villages would agree to participate and accept randomisation; 30 women could be recruited in 70% of villages), and retention of participants (50% of women retained from baseline to endline). Clusters were assigned to IG or CG using a computer-generated randomisation schedule. Neither participants nor those delivering interventions were blinded, but those assessing outcomes were blinded to group assignment. Results All villages contacted agreed to participate and accepted randomisation. 36 women were recruited per village; 432 participants were randomised (IG n=216; CG n=216). No clusters were lost to follow-up. The main analysis included 86% (373/432) of participants, 90% (195/216) from the IG and 82% (178/216) from the CG. Conclusions Criteria related to feasibility were satisfied, giving us confidence that we can successfully conduct a larger cluster randomised trial. Methodological lessons will inform design of the main study. Trial registration number ISRCTN16703097 PMID:26384721
Thermal antinociception after dexmedetomidine administration in cats: a comparison between intramuscular and oral transmucosal administration.

PubMed

Slingsby, Louisa S; Taylor, Polly M; Monroe, Taylor

2009-10-01

Dexmedetomidine 40microg/kg was administered either intramuscularly (IM) or oral transmucosally (OTM) to 12 cats in a randomised cross-over study. Thermal nociceptive thresholds and visual analogue scale (VAS) sedation scores were obtained before and at regular intervals up to 24h after test drug administration. The summary measures of overall mean threshold, overall mean VAS sedation plus onset, offset and duration of analgesia were investigated using a univariate general linear model. There were no significant differences between treatment groups. Data are presented as mean+/-standard deviation: delta T mean increase over time (IM 6 degrees C+/-3 degrees C, OTM 6 degrees C+/-2 degrees C); overall mean VAS (IM 43+/-9 OTM 39+/-1); onset (IM 35+/-32 and OTM 30+/-40min); offset (IM 96+/-56 and OTM 138+/-135min); duration (IM 61+/-47 OTM 99+/-124min). Dexmedetomidine is well absorbed through the oral mucosa in cats since OTM and IM administration of dexmedetomidine 40microg/kg produced similar overall sedative and antinociceptive effects.
Serotonin enhances the impact of health information on food choice.

PubMed

Vlaev, Ivo; Crockett, Molly J; Clark, Luke; Müller, Ulrich; Robbins, Trevor W

2017-06-01

Serotonin has been implicated in promoting self-control, regulation of hunger and physiological homeostasis, and regulation of caloric intake. However, it remains unclear whether the effects of serotonin on caloric intake reflect purely homeostatic mechanisms, or whether serotonin also modulates cognitive processes involved in dietary decision making. We investigated the effects of an acute dose of the serotonin reuptake inhibitor citalopram on choices between food items that differed along taste and health attributes, compared with placebo and the noradrenaline reuptake inhibitor atomoxetine. Twenty-seven participants attended three sessions and received single doses of atomoxetine, citalopram, and placebo in a double-blind randomised cross-over design. Relative to placebo, citalopram increased choices of more healthy foods over less healthy foods. Citalopram also increased the emphasis on health considerations in decisions. Atomoxetine did not affect decision making relative to placebo. The results support the hypothesis that serotonin may influence food choice by enhancing a focus on long-term goals. The findings are relevant for understanding decisions about food consumption and also for treating health conditions such as eating disorders and obesity.
The effects of the Bowen technique on hamstring flexibility over time: a randomised controlled trial.

PubMed

Marr, Michelle; Baker, Julian; Lambon, Nicky; Perry, Jo

2011-07-01

The hamstring muscles are regularly implicated in recurrent injuries, movement dysfunction and low back pain. Links between limited flexibility and development of neuromusculoskeletal symptoms are frequently reported. The Bowen Technique is used to treat many conditions including lack of flexibility. The study set out to investigate the effect of the Bowen Technique on hamstring flexibility over time. An assessor-blind, prospective, randomised controlled trial was performed on 120 asymptomatic volunteers. Participants were randomly allocated into a control group or Bowen group. Three flexibility measurements occurred over one week, using an active knee extension test. The intervention group received a single Bowen treatment. A repeated measures univariate analysis of variance, across both groups for the three time periods, revealed significant within-subject and between-subject differences for the Bowen group. Continuing increases in flexibility levels were observed over one week. No significant change over time was noted for the control group. Copyright © 2010 Elsevier Ltd. All rights reserved.
Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees.

PubMed

Theeven, Patrick; Hemmen, Bea; Rings, Frans; Meys, Guido; Brink, Peter; Smeets, Rob; Seelen, Henk

2011-10-01

To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. Randomised cross-over trial. Forty-one persons with unilateral above-knee or knee disarticulation limb loss, classified as Medicare Functional Classification Level-2 (MFCL-2). Participants were measured in 3 conditions, i.e. using a mechanically controlled knee joint and two types of microprocessor-controlled prosthetic knee joints. Functional performance level was assessed using a test in which participants performed 17 simulated activities of daily living (Assessment of Daily Activity Performance in Transfemoral amputees test). Performance time was measured and self-perceived level of difficulty was scored on a visual analogue scale for each activity. High levels of within-group variability in functional performance obscured detection of any effects of using a microprocessor-controlled prosthetic knee joint. Data analysis after stratification of the participants into 3 subgroups, i.e. participants with a "low", "intermediate" and "high" functional mobility level, showed that the two higher functional subgroups performed significantly faster using microprocessor-controlled prosthetic knee joints. MFCL-2 amputees constitute a heterogeneous patient group with large variation in functional performance levels. A substantial part of this group seems to benefit from using a microprocessor-controlled prosthetic knee joint when performing activities of daily living.
An Equivalent cross-section Framework for improving computational efficiency in Distributed Hydrologic Modelling

NASA Astrophysics Data System (ADS)

Khan, Urooj; Tuteja, Narendra; Ajami, Hoori; Sharma, Ashish

2014-05-01

While the potential uses and benefits of distributed catchment simulation models is undeniable, their practical usage is often hindered by the computational resources they demand. To reduce the computational time/effort in distributed hydrological modelling, a new approach of modelling over an equivalent cross-section is investigated where topographical and physiographic properties of first-order sub-basins are aggregated to constitute modelling elements. To formulate an equivalent cross-section, a homogenization test is conducted to assess the loss in accuracy when averaging topographic and physiographic variables, i.e. length, slope, soil depth and soil type. The homogenization test indicates that the accuracy lost in weighting the soil type is greatest, therefore it needs to be weighted in a systematic manner to formulate equivalent cross-sections. If the soil type remains the same within the sub-basin, a single equivalent cross-section is formulated for the entire sub-basin. If the soil type follows a specific pattern, i.e. different soil types near the centre of the river, middle of hillslope and ridge line, three equivalent cross-sections (left bank, right bank and head water) are required. If the soil types are complex and do not follow any specific pattern, multiple equivalent cross-sections are required based on the number of soil types. The equivalent cross-sections are formulated for a series of first order sub-basins by implementing different weighting methods of topographic and physiographic variables of landforms within the entire or part of a hillslope. The formulated equivalent cross-sections are then simulated using a 2-dimensional, Richards' equation based distributed hydrological model. The simulated fluxes are multiplied by the weighted area of each equivalent cross-section to calculate the total fluxes from the sub-basins. The simulated fluxes include horizontal flow, transpiration, soil evaporation, deep drainage and soil moisture. To assess the accuracy of equivalent cross-section approach, the sub-basins are also divided into equally spaced multiple hillslope cross-sections. These cross-sections are simulated in a fully distributed settings using the 2-dimensional, Richards' equation based distributed hydrological model. The simulated fluxes are multiplied by the contributing area of each cross-section to get total fluxes from each sub-basin referred as reference fluxes. The equivalent cross-section approach is investigated for seven first order sub-basins of the McLaughlin catchment of the Snowy River, NSW, Australia, and evaluated in Wagga-Wagga experimental catchment. Our results show that the simulated fluxes using an equivalent cross-section approach are very close to the reference fluxes whereas computational time is reduced of the order of ~4 to ~22 times in comparison to the fully distributed settings. The transpiration and soil evaporation are the dominant fluxes and constitute ~85% of actual rainfall. Overall, the accuracy achieved in dominant fluxes is higher than the other fluxes. The simulated soil moistures from equivalent cross-section approach are compared with the in-situ soil moisture observations in the Wagga-Wagga experimental catchment in NSW, and results found to be consistent. Our results illustrate that the equivalent cross-section approach reduces the computational time significantly while maintaining the same order of accuracy in predicting the hydrological fluxes. As a result, this approach provides a great potential for implementation of distributed hydrological models at regional scales.
Cross-sectional associations between dietary intake and carotid intima media thickness in type 2 diabetes: baseline data from a randomised trial

PubMed Central

Chiavaroli, Laura; Mirrahimi, Arash; Ireland, Christopher; Mitchell, Sandra; Sahye-Pudaruth, Sandhya; Coveney, Judy; Olowoyeye, Omodele; Patel, Darshna; de Souza, Russell J; Augustin, Livia S A; Bashyam, Balachandran; Pichika, Sathish Chandra; Blanco Mejia, Sonia; Nishi, Stephanie K; Leiter, Lawrence A; Josse, Robert G; McKeown-Eyssen, Gail E; Moody, Alan R; Kendall, Cyril W C; Sievenpiper, John L; Jenkins, David J A

2017-01-01

Objective To assess associations between dietary intake and carotid intima media thickness (CIMT) by carotid ultrasound (CUS), a surrogate marker of cardiovascular disease (CVD) risk, in those with type 2 diabetes. Design Cross-sectional analysis of baseline data from 325 participants from three randomised controlled trials collected in the same way. Setting Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Canada. Participants 325 participants with type 2 diabetes, taking oral antidiabetic agents, with an HbA1c between 6.5% and 8.0% at screening, without a recent cardiovascular event. Main outcome measures CIMT by CUS and associations with dietary intake from 7-day food records, as well as anthropometric measures and fasting serum samples. Results CIMT was significantly inversely associated with dietary pulse intake (β=−0.019, p=0.009), available carbohydrate (β=−0.004, p=0.008), glycaemic load (β=−0.001, p=0.007) and starch (β=−0.126, p=0.010), and directly associated with total (β=0.004, p=0.028) and saturated (β=0.012, p=0.006) fat intake in multivariate regression models adjusted for age, smoking, previous CVD event, blood pressure medication, antidiabetic medication and ultrasonographer. Conclusions Lower CIMT was significantly associated with greater consumption of dietary pulses and carbohydrates and lower total and saturated fat intake, suggesting a potential role for diet in CVD risk management in type 2 diabetes. Randomised controlled trials are anticipated to explore these associations further. Trial registration number NCT01063374. PMID:28336747
The tomato sauce making process affects the bioaccessibility and bioavailability of tomato phenolics: a pharmacokinetic study.

PubMed

Martínez-Huélamo, Miriam; Tulipani, Sara; Estruch, Ramón; Escribano, Elvira; Illán, Montserrat; Corella, Dolores; Lamuela-Raventós, Rosa M

2015-04-15

Tomato sauce is the most commonly consumed processed tomato product worldwide, but very little is known about how the manufacturing process may affect the phenolic composition and bioavailability after consumption. In a prospective randomised, cross-over intervention study, we analysed the plasma and urinary levels of tomato phenolic compounds and their metabolites after acute consumption of raw tomatoes and tomato sauce, enriched or not with refined olive oil during production. Respectively, eleven and four phenolic metabolites were found in urine and plasma samples. The plasma concentration and urinary excretion of naringenin glucuronide were both significantly higher after the consumption of tomato sauce than raw tomatoes. The results suggest that the mechanical and thermal treatments during tomato sauce manufacture may help to deliver these potentially bioactive phenolics from the food matrix more effectively than the addition of an oil component, thus increasing their bioavailability. Copyright © 2014 Elsevier Ltd. All rights reserved.
Dark chocolate: consumption for pleasure or therapy?

PubMed

Lippi, Giuseppe; Franchini, Massimo; Montagnana, Martina; Favaloro, Emmanuel J; Guidi, Gian Cesare; Targher, Giovanni

2009-11-01

Traditional chocolate is derived from the cocoa bean, which is one of the most concentrated sources of flavanols, a subgroup of the natural antioxidant plant compounds called flavonoids. Accumulating evidence from the past 10 years demonstrates that moderate consumption of chocolate, especially dark chocolate, may exert protective effects against the development of cardiovascular disease. Several mechanisms have been proposed to explain this positive influence, including metabolic, antihypertensive, anti-inflammatory, and anti-thrombotic effects, as well as effects on insulin sensitivity and vascular endothelial function. Should these results be confirmed in randomised, controlled, cross-over, multi-dose trials, then the pleasure associated with chocolate consumption might also be justified from health and psychological perspectives. However, since dark chocolate has substantially higher levels of flavonoids than milk chocolate, and milk proteins may inhibit absorption of flavonoids, it might be preferable to consume dark chocolate than the white (milk) variety.
Comparative bioavailability study of clonazepam after oral administration of two tablet formulations.

PubMed

Chauhan, B L; Sane, S P; Revankar, S N; Rammamurthy, L; Doshi, B; Bhatt, A D; Bhate, V R; Kulkarni, R D

2000-10-01

To assess the bioavailability of clonazepam from two brands of 2 mg tablet formulations--Epitril and reference brand. A two-way randomised cross-over bioavailability study was carried out in 12 healthy male volunteers. Coded plasma samples were analysed for levels of clonazepam by high performance liquid chromatography (HPLC) method. The mean Cmax, Tmax t1/2 beta and AUC (0-48) for Epitril were: 16.31 +/- 3.07 ng/mL, 1.63 +/- 0.48 h, 46.97 +/- 12.26 h and 207.70 +/- 57.07 ng/ml.h; for reference brand were 19.75 +/- 5.95 ng/mL, 1.42 +/- 0.29 h, 46.88 +/- 11.29 h and 215.70 +/- 50.89 ng/ml.h respectively. These were comparable and the differences were not statistically significant. Based on above pharmacokinetic parameters, Epitril was bioequivalent to reference brand.
A comparison of the efficacy of ketotifen (HC 20-511) with sodium cromoglycate (SCG) in skin test positive asthma.

PubMed Central

Clarke, C W; May, C S

1980-01-01

1 Ketotifen (HC 20-511 Sandoz) 1 mg twice daily for 12 weeks was found to be equivalent to sodium cromoglycate (SCG) 20 mg four times daily for 12 weeks in 35 skin test positive asthmatic patients in a randomised double-blind cross-over study. 2 No statistically significant difference between the two drugs in mean values for daily peak flow rates, diary card scores and spirometry at monthly visits was demonstrated. 3 Treatment failures as judged by severe asthma requiring withdrawal from the trial or addition of short courses of prednisone occurred in three patients on each drug. 4 Sedation was noted by 10 patients onHC 20-511 and 5 on SCG. 5 Weight loss was noted in those patients on SCG, but not those on HC 20-511. PMID:6108129
Dark chocolate or tomato extract for prehypertension: a randomised controlled trial.

PubMed

Ried, Karin; Frank, Oliver R; Stocks, Nigel P

2009-07-08

Flavanol-rich chocolate and lycopene-rich tomato extract have attracted interest as potential alternative treatment options for hypertension, a known risk factor for cardiovascular morbidity and mortality. Treatment of prehypertension (SBP 120-139/DBP 80-89 mmHg) may forestall progression to hypertension. However, there has been only limited research into non-pharmacological treatment options for prehypertension. We investigated the effect of dark chocolate or tomato extract on blood pressure, and their acceptability as an ongoing treatment option in a prehypertensive population. Our trial consisted of two phases: a randomised controlled three-group-parallel trial over 12 weeks (phase 1) followed by a crossover of the two active treatment arms over an additional 12-week period (phase 2). Group 1 received a 50 g daily dose of dark chocolate with 70% cocoa containing 750 mg polyphenols, group 2 were allocated one tomato extract capsule containing 15 mg lycopene per day, and group 3 received one placebo capsule daily over 8 weeks followed by a 4-week washout period. In phase 2 the active treatment groups were crossed over to receive the alternative treatment. Median blood pressure, weight, and abdominal circumference were measured 4-weekly, and other characteristics including physical activity, general health, energy, mood, and acceptability of treatment were assessed by questionnaire at 0, 8 and 20 weeks. We analysed changes over time using a linear mixed model, and one time point differences using Kruskal-Wallis, Fisher's-Exact, or t-tests. Thirty-six prehypertensive healthy adult volunteers completed the 6-month trial. Blood pressure changes over time within groups and between groups were not significant and independent of treatment. Weight and other characteristics did not change significantly during the trial. However, a marked difference in acceptability between the two treatment forms (chocolate or capsule) was revealed (p < 0.0001). Half of the participants allocated to the chocolate treatment found it hard to eat 50 g of dark chocolate every day and 20% considered it an unacceptable long-term treatment option, whereas all participants found it easy and acceptable to take a capsule each day for blood pressure. Our study did not find a blood pressure lowering effect of dark chocolate or tomato extract in a prehypertensive population. Practicability of chocolate as a long-term treatment option may be limited. http://www.anzctr.org.au Identifier: ACTRN12609000047291.
Dark chocolate or tomato extract for prehypertension: a randomised controlled trial

PubMed Central

Ried, Karin; Frank, Oliver R; Stocks, Nigel P

2009-01-01

Background Flavanol-rich chocolate and lycopene-rich tomato extract have attracted interest as potential alternative treatment options for hypertension, a known risk factor for cardiovascular morbidity and mortality. Treatment of prehypertension (SBP 120–139/DBP 80–89 mmHg) may forestall progression to hypertension. However, there has been only limited research into non-pharmacological treatment options for prehypertension. We investigated the effect of dark chocolate or tomato extract on blood pressure, and their acceptability as an ongoing treatment option in a prehypertensive population. Methods Our trial consisted of two phases: a randomised controlled three-group-parallel trial over 12 weeks (phase 1) followed by a crossover of the two active treatment arms over an additional 12-week period (phase 2). Group 1 received a 50 g daily dose of dark chocolate with 70% cocoa containing 750 mg polyphenols, group 2 were allocated one tomato extract capsule containing 15 mg lycopene per day, and group 3 received one placebo capsule daily over 8 weeks followed by a 4-week washout period. In phase 2 the active treatment groups were crossed over to receive the alternative treatment. Median blood pressure, weight, and abdominal circumference were measured 4-weekly, and other characteristics including physical activity, general health, energy, mood, and acceptability of treatment were assessed by questionnaire at 0, 8 and 20 weeks. We analysed changes over time using a linear mixed model, and one time point differences using Kruskal-Wallis, Fisher's-Exact, or t-tests. Results Thirty-six prehypertensive healthy adult volunteers completed the 6-month trial. Blood pressure changes over time within groups and between groups were not significant and independent of treatment. Weight and other characteristics did not change significantly during the trial. However, a marked difference in acceptability between the two treatment forms (chocolate or capsule) was revealed (p < 0.0001). Half of the participants allocated to the chocolate treatment found it hard to eat 50 g of dark chocolate every day and 20% considered it an unacceptable long-term treatment option, whereas all participants found it easy and acceptable to take a capsule each day for blood pressure. Conclusion Our study did not find a blood pressure lowering effect of dark chocolate or tomato extract in a prehypertensive population. Practicability of chocolate as a long-term treatment option may be limited. Trial registration Identifier: ACTRN12609000047291 PMID:19583878
CAGE IIIA Distributed Simulation Design Methodology

DTIC Science & Technology

2014-05-01

2 VHF Very High Frequency VLC Video LAN Codec – an Open-source cross-platform multimedia player and framework VM Virtual Machine VOIP Voice Over...Implementing Defence Experimentation (GUIDEx). The key challenges for this methodology are with understanding how to: • design it o define the...operation and to be available in the other nation’s simulations. The challenge for the CAGE campaign of experiments is to continue to build upon this
Large-scale structure perturbation theory without losing stream crossing

DOE PAGES

McDonald, Patrick; Vlah, Zvonimir

2018-01-10

Here, we suggest an approach to perturbative calculations of large-scale clustering in the Universe that includes from the start the stream crossing (multiple velocities for mass elements at a single position) that is lost in traditional calculations. Starting from a functional integral over displacement, the perturbative series expansion is in deviations from (truncated) Zel’dovich evolution, with terms that can be computed exactly even for stream-crossed displacements. We evaluate the one-loop formulas for displacement and density power spectra numerically in 1D, finding dramatic improvement in agreement with N-body simulations compared to the Zel’dovich power spectrum (which is exact in 1D upmore » to stream crossing). Beyond 1D, our approach could represent an improvement over previous expansions even aside from the inclusion of stream crossing, but we have not investigated this numerically. In the process we show how to achieve effective-theory-like regulation of small-scale fluctuations without free parameters.« less
Large-scale structure perturbation theory without losing stream crossing

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, Patrick; Vlah, Zvonimir

Here, we suggest an approach to perturbative calculations of large-scale clustering in the Universe that includes from the start the stream crossing (multiple velocities for mass elements at a single position) that is lost in traditional calculations. Starting from a functional integral over displacement, the perturbative series expansion is in deviations from (truncated) Zel’dovich evolution, with terms that can be computed exactly even for stream-crossed displacements. We evaluate the one-loop formulas for displacement and density power spectra numerically in 1D, finding dramatic improvement in agreement with N-body simulations compared to the Zel’dovich power spectrum (which is exact in 1D upmore » to stream crossing). Beyond 1D, our approach could represent an improvement over previous expansions even aside from the inclusion of stream crossing, but we have not investigated this numerically. In the process we show how to achieve effective-theory-like regulation of small-scale fluctuations without free parameters.« less
The effect of transcranial direct current stimulation (tDCS) on locomotion and balance in patients with chronic stroke: study protocol for a randomised controlled trial.

PubMed

Geiger, M; Supiot, A; Zory, R; Aegerter, P; Pradon, D; Roche, N

2017-10-23

Following stroke, patients are often left with hemiparesis that reduces balance and gait capacity. A recent, non-invasive technique, transcranial direct current stimulation, can be used to modify cortical excitability when used in an anodal configuration. It also increases the excitability of spinal neuronal circuits involved in movement in healthy subjects. Many studies in patients with stroke have shown that this technique can improve motor, sensory and cognitive function. For example, anodal tDCS has been shown to improve motor performance of the lower limbs in patients with stroke, such as voluntary quadriceps strength, toe-pinch force and reaction time. Nevertheless, studies of motor function have been limited to simple tasks. Surprisingly, the effects of tDCS on the locomotion and balance of patients with chronic stroke have never been evaluated. In this study, we hypothesise that anodal tDCS will improve balance and gait parameters in patients with chronic stroke-related hemiparesis through its effects at cortical and spinal level. This is a prospective, randomised, placebo-controlled, double-blinded, single-centre, cross-over study over 36 months. Forty patients with chronic stroke will be included. Each patient will participate in three visits: an inclusion visit, and two visits during which they will all undergo either one 30-min session of transcranial direct current stimulation or one 30-min session of placebo stimulation in a randomised order. Evaluations will be carried out before, during and twice after stimulation. The primary outcome is the variability of the displacement of the centre of mass during gait and a static-balance task. Secondary outcomes include clinical and functional measures before and after stimulation. A three-dimensional gait analysis, and evaluation of static balance on a force platform will be also conducted before, during and after stimulation. These results should constitute a useful database to determine the aspects of complex motor function that are the most improved by transcranial direct current stimulation in patients with hemiparesis. It is the first essential step towards validating this technique as a treatment, coupled with task-oriented training. ClinicalTrials.gov, ID: NCT02134158 . First received on 18 December 2013; last updated on 14 September 2016. Other study ID numbers: P120135 / AOM12126, 2013-A00952-43.
Simulation-based power calculations for planning a two-stage individual participant data meta-analysis.

PubMed

Ensor, Joie; Burke, Danielle L; Snell, Kym I E; Hemming, Karla; Riley, Richard D

2018-05-18

Researchers and funders should consider the statistical power of planned Individual Participant Data (IPD) meta-analysis projects, as they are often time-consuming and costly. We propose simulation-based power calculations utilising a two-stage framework, and illustrate the approach for a planned IPD meta-analysis of randomised trials with continuous outcomes where the aim is to identify treatment-covariate interactions. The simulation approach has four steps: (i) specify an underlying (data generating) statistical model for trials in the IPD meta-analysis; (ii) use readily available information (e.g. from publications) and prior knowledge (e.g. number of studies promising IPD) to specify model parameter values (e.g. control group mean, intervention effect, treatment-covariate interaction); (iii) simulate an IPD meta-analysis dataset of a particular size from the model, and apply a two-stage IPD meta-analysis to obtain the summary estimate of interest (e.g. interaction effect) and its associated p-value; (iv) repeat the previous step (e.g. thousands of times), then estimate the power to detect a genuine effect by the proportion of summary estimates with a significant p-value. In a planned IPD meta-analysis of lifestyle interventions to reduce weight gain in pregnancy, 14 trials (1183 patients) promised their IPD to examine a treatment-BMI interaction (i.e. whether baseline BMI modifies intervention effect on weight gain). Using our simulation-based approach, a two-stage IPD meta-analysis has < 60% power to detect a reduction of 1 kg weight gain for a 10-unit increase in BMI. Additional IPD from ten other published trials (containing 1761 patients) would improve power to over 80%, but only if a fixed-effect meta-analysis was appropriate. Pre-specified adjustment for prognostic factors would increase power further. Incorrect dichotomisation of BMI would reduce power by over 20%, similar to immediately throwing away IPD from ten trials. Simulation-based power calculations could inform the planning and funding of IPD projects, and should be used routinely.

Head Position in Stroke Trial (HeadPoST)--sitting-up vs lying-flat positioning of patients with acute stroke: study protocol for a cluster randomised controlled trial.

PubMed

Muñoz-Venturelli, Paula; Arima, Hisatomi; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Billot, Laurent; Boaden, Elizabeth; Hackett, Maree L; Heritier, Stephane; Jan, Stephen; Middleton, Sandy; Olavarría, Verónica V; Lim, Joyce Y; Lindley, Richard I; Heeley, Emma; Robinson, Thompson; Pontes-Neto, Octavio; Natsagdorj, Lkhamtsoo; Lin, Ruey-Tay; Watkins, Caroline; Anderson, Craig S

2015-06-05

Positioning a patient lying-flat in the acute phase of ischaemic stroke may improve recovery and reduce disability, but such a possibility has not been formally tested in a randomised trial. We therefore initiated the Head Position in Stroke Trial (HeadPoST) to determine the effects of lying-flat (0°) compared with sitting-up (≥ 30°) head positioning in the first 24 hours of hospital admission for patients with acute stroke. We plan to conduct an international, cluster randomised, crossover, open, blinded outcome-assessed clinical trial involving 140 study hospitals (clusters) with established acute stroke care programs. Each hospital will be randomly assigned to sequential policies of lying-flat (0°) or sitting-up (≥ 30°) head position as a 'business as usual' stroke care policy during the first 24 hours of admittance. Each hospital is required to recruit 60 consecutive patients with acute ischaemic stroke (AIS), and all patients with acute intracerebral haemorrhage (ICH) (an estimated average of 10), in the first randomised head position policy before crossing over to the second head position policy with a similar recruitment target. After collection of in-hospital clinical and management data and 7-day outcomes, central trained blinded assessors will conduct a telephone disability assessment with the modified Rankin Scale at 90 days. The primary outcome for analysis is a shift (defined as improvement) in death or disability on this scale. For a cluster size of 60 patients with AIS per intervention and with various assumptions including an intracluster correlation coefficient of 0.03, a sample size of 16,800 patients at 140 centres will provide 90 % power (α 0.05) to detect at least a 16 % relative improvement (shift) in an ordinal logistic regression analysis of the primary outcome. The treatment effect will also be assessed in all patients with ICH who are recruited during each treatment study period. HeadPoST is a large international clinical trial in which we will rigorously evaluate the effects of different head positioning in patients with acute stroke. ClinicalTrials.gov identifier: NCT02162017 (date of registration: 27 April 2014); ANZCTR identifier: ACTRN12614000483651 (date of registration: 9 May 2014). Protocol version and date: version 2.2, 19 June 2014.
Surgery versus conservative treatment in patients with type A distal radius fractures, a randomized controlled trial

PubMed Central

2014-01-01

Background Fractures of the distal radius are common and account for an estimated 17% of all fractures diagnosed. Two-thirds of these fractures are displaced and require reduction. Although distal radius fractures, especially extra-articular fractures, are considered to be relatively harmless, inadequate treatment may result in impaired function of the wrist. Initial treatment according to Dutch guidelines consists of closed reduction and plaster immobilisation. If fracture redisplacement occurs, surgical treatment is recommended. Recently, the use of volar locking plates has become more popular. The aim of this study is to compare the functional outcome following surgical reduction and fixation with a volar locking plate with the functional outcome following closed reduction and plaster immobilisation in patients with displaced extra-articular distal radius fractures. Design This single blinded randomised controlled trial will randomise between open reduction and internal fixation with a volar locking plate (intervention group) and closed reduction followed by plaster immobilisation (control group). The study population will consist of all consecutive adult patients who are diagnosed with a displaced extra-articular distal radius fracture, which has been adequately reduced at the Emergency Department. The primary outcome (functional outcome) will be assessed by means of the Disability Arm Shoulder Hand Score (DASH). Secondary outcomes comprise the Patient-Rated Wrist Evaluation score (PRWE), quality of life, pain, range of motion, radiological parameters, complications and cross-overs. Since the treatment allocated involves a surgical procedure, randomisation status will not be blinded. However, the researcher assessing the outcome at one year will be unaware of the treatment allocation. In total, 90 patients will be included and this trial will require an estimated time of two years to complete and will be conducted in the Academic Medical Centre Amsterdam and its partners of the regional trauma care network. Dicussion Ideally, patients would be randomised before any kind of treatment has been commenced. However, we deem it not patient-friendly to approach possible participants before adequate reduction has been obtained. Trial registration This study is registered at the Netherlands Trial Register (NTR3113) and was granted permission by the Medical Ethical Review Committee of the Academic Medical Centre on 01-10-2012. PMID:24642190
CONSORT item reporting quality in the top ten ranked journals of critical care medicine in 2011: a retrospective analysis.

PubMed

Stevanovic, Ana; Schmitz, Sabine; Rossaint, Rolf; Schürholz, Tobias; Coburn, Mark

2015-01-01

Reporting randomised controlled trials is a key element in order to disseminate research findings. The CONSORT statement was introduced to improve the reporting quality. We assessed the adherence to the CONSORT statement of randomised controlled trials published 2011 in the top ten ranked journals of critical care medicine (ISI Web of Knowledge 2011, Thomson Reuters, London UK). Design. We performed a retrospective cross sectional data analysis. Setting. This study was executed at the University Hospital of RWTH, Aachen. Participants. We selected the following top ten listed journals according to ISI Web of Knowledge (Thomson Reuters, London, UK) critical care medicine ranking in the year 2011: American Journal of Respiratory and Critical Care Medicine, Critical Care Medicine, Intensive Care Medicine, CHEST, Critical Care, Journal of Neurotrauma, Resuscitation, Pediatric Critical Care Medicine, Shock and Minerva Anestesiologica. Main outcome measures. We screened the online table of contents of each included journal, to identify the randomised controlled trials. The adherence to the items of the CONSORT Checklist in each trial was evaluated. Additionally we correlated the citation frequency of the articles and the impact factor of the respective journal with the amount of reported items per trial. We analysed 119 randomised controlled trials and found, 15 years after the implementation of the CONSORT statement, that a median of 61,1% of the checklist-items were reported. Only 55.5% of the articles were identified as randomised trials in their titles. The citation frequency of the trials correlated significantly (rs = 0,433; p<0,001 and r = 0,331; p<0,001) to the CONSORT statement adherence. The impact factor showed also a significant correlation to the CONSORT adherence (r = 0,386; p<0,001). The reporting quality of randomised controlled trials in the field of critical care medicine remains poor and needs considerable improvement.
Determination of Vertical Borehole and Geological Formation Properties using the Crossed Contour Method.

PubMed

Leyde, Brian P; Klein, Sanford A; Nellis, Gregory F; Skye, Harrison

2017-03-01

This paper presents a new method called the Crossed Contour Method for determining the effective properties (borehole radius and ground thermal conductivity) of a vertical ground-coupled heat exchanger. The borehole radius is used as a proxy for the overall borehole thermal resistance. The method has been applied to both simulated and experimental borehole Thermal Response Test (TRT) data using the Duct Storage vertical ground heat exchanger model implemented in the TRansient SYstems Simulation software (TRNSYS). The Crossed Contour Method generates a parametric grid of simulated TRT data for different combinations of borehole radius and ground thermal conductivity in a series of time windows. The error between the average of the simulated and experimental bore field inlet and outlet temperatures is calculated for each set of borehole properties within each time window. Using these data, contours of the minimum error are constructed in the parameter space of borehole radius and ground thermal conductivity. When all of the minimum error contours for each time window are superimposed, the point where the contours cross (intersect) identifies the effective borehole properties for the model that most closely represents the experimental data in every time window and thus over the entire length of the experimental data set. The computed borehole properties are compared with results from existing model inversion methods including the Ground Property Measurement (GPM) software developed by Oak Ridge National Laboratory, and the Line Source Model.
Using an internet intervention to support self-management of low back pain in primary care: findings from a randomised controlled feasibility trial (SupportBack)

PubMed Central

Geraghty, Adam W A; Stanford, Rosie; Stuart, Beth; Little, Paul; Roberts, Lisa C; Foster, Nadine E; Hill, Jonathan C; Hay, Elaine M; Turner, David; Malakan, Wansida; Leigh, Linda; Yardley, Lucy

2018-01-01

Objective To determine the feasibility of a randomised controlled trial of an internet intervention for low back pain (LBP) using three arms: (1) usual care, (2) usual care plus an internet intervention or (3) usual care plus an internet intervention with additional physiotherapist telephone support. Design and setting A three-armed randomised controlled feasibility trial conducted in 12 general practices in England. Participants Primary care patients aged over 18 years, with current LBP, access to the internet and without indicators of serious spinal pathology or systemic illness. Interventions The ‘SupportBack’ internet intervention delivers a 6-week, tailored programme, focused on graded goal setting, self-monitoring and provision of tailored feedback to encourage physical activity. Additional physiotherapist telephone support consisted of three brief telephone calls over a 4-week period, to address any concerns and provide reassurance. Outcomes The primary outcomes were the feasibility of the trial design including recruitment, adherence and retention at follow-up. Secondary descriptive and exploratory analyses were conducted on clinical outcomes including LBP-related disability at 3 months follow-up. Results Primary outcomes: 87 patients with LBP were recruited (target 60–90) over 6 months, and there were 3 withdrawals. Adherence to the intervention was higher in the physiotherapist-supported arm, compared with the stand-alone internet intervention. Trial physiotherapists adhered to the support protocol. Overall follow-up rate on key clinical outcomes at 3 months follow-up was 84%. Conclusions This study demonstrated the feasibility of a future definitive randomised controlled trial to determine the clinical and cost-effectiveness of the SupportBack intervention in primary care patients with LBP. Trial registration number ISRCTN31034004; Results. PMID:29525768
Evaluation and development of a novel binocular treatment (I-BiT™) system using video clips and interactive games to improve vision in children with amblyopia ('lazy eye'): study protocol for a randomised controlled trial.

PubMed

Foss, Alexander J; Gregson, Richard M; MacKeith, Daisy; Herbison, Nicola; Ash, Isabel M; Cobb, Sue V; Eastgate, Richard M; Hepburn, Trish; Vivian, Anthony; Moore, Diane; Haworth, Stephen M

2013-05-20

Amblyopia (lazy eye) affects the vision of approximately 2% of all children. Traditional treatment consists of wearing a patch over their 'good' eye for a number of hours daily, over several months. This treatment is unpopular and compliance is often low. Therefore results can be poor. A novel binocular treatment which uses 3D technology to present specially developed computer games and video footage (I-BiT™) has been studied in a small group of patients and has shown positive results over a short period of time. The system is therefore now being examined in a randomised clinical trial. Seventy-five patients aged between 4 and 8 years with a diagnosis of amblyopia will be randomised to one of three treatments with a ratio of 1:1:1 - I-BiT™ game, non-I-BiT™ game, and I-BiT™ DVD. They will be treated for 30 minutes once weekly for 6 weeks. Their visual acuity will be assessed independently at baseline, mid-treatment (week 3), at the end of treatment (week 6) and 4 weeks after completing treatment (week 10). The primary endpoint will be the change in visual acuity from baseline to the end of treatment. Secondary endpoints will be additional visual acuity measures, patient acceptability, compliance and the incidence of adverse events. This is the first randomised controlled trial using the I-BiT™ system. The results will determine if the I-BiT™ system is effective in the treatment of amblyopia and will also determine the optimal treatment for future development. ClinicalTrials.gov identifier: NCT01702727.
Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial

PubMed Central

Hollands, Kristen L.; Pelton, Trudy A.; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M.; Wing, Alan M.; Tyson, Sarah F.; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M.

2015-01-01

Objectives Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. Design This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services Participants Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments Intervention Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Results Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Conclusions Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Trial Registration Clinicaltrials.gov NCT01600391 PMID:26445137
Randomised clinical simulation designed to evaluate the effect of telemedicine using Google Glass on cardiopulmonary resuscitation (CPR).

PubMed

Pérez Alonso, Nuria; Pardo Rios, Manuel; Juguera Rodriguez, Laura; Vera Catalan, Tomas; Segura Melgarejo, Francisca; Lopez Ayuso, Belen; Martí Nez Riquelme, Carolina; Lasheras Velasco, Joaquin

2017-11-01

Through a clinical simulation, this study aims to assess the effect of telematics support through Google Glass (GG) from an expert physician on performance of cardiopulmonary resuscitation (CPR) performed by a group of nurses, as compared with a control group of nurses receiving no assistance. This was a randomised study carried out at the Catholic University of Murcia (November 2014-February 2015). Nursing professionals from the Emergency Medical Services in Murcia (Spain) were asked to perform in a clinical simulation of cardiac arrest. Half of the nurses were randomly chosen to receive coaching from physicians through GG, while the other half did not receive any coaching (controls). The main outcome of the study expected was successful defibrillation, which restores sinus rhythm. Thirty-six nurses were enrolled in each study group. Statistically significant differences were found in the percentages of successful defibrillation (100% GG vs 78% control; p=0005) and CPR completion times: 213.91 s for GG and 250.31 s for control (average difference=36.39 s (95% CI 12.03 to 60.75), p=0.004). Telematics support by an expert through GG improves success rates and completion times while performing CPR in simulated clinical situations for nurses in simulated scenarios. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Cross-layer restoration with software defined networking based on IP over optical transport networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Cheng, Lei; Deng, Junni; Zhao, Yongli; Zhang, Jie; Lee, Young

2015-10-01

The IP over optical transport network is a very promising networking architecture applied to the interconnection of geographically distributed data centers due to the performance guarantee of low delay, huge bandwidth and high reliability at a low cost. It can enable efficient resource utilization and support heterogeneous bandwidth demands in highly-available, cost-effective and energy-effective manner. In case of cross-layer link failure, to ensure a high-level quality of service (QoS) for user request after the failure becomes a research focus. In this paper, we propose a novel cross-layer restoration scheme for data center services with software defined networking based on IP over optical network. The cross-layer restoration scheme can enable joint optimization of IP network and optical network resources, and enhance the data center service restoration responsiveness to the dynamic end-to-end service demands. We quantitatively evaluate the feasibility and performances through the simulation under heavy traffic load scenario in terms of path blocking probability and path restoration latency. Numeric results show that the cross-layer restoration scheme improves the recovery success rate and minimizes the overall recovery time.
Fluids and diuretics for acute ureteric colic.

PubMed

Worster, Andrew S; Bhanich Supapol, Wendy

2012-02-15

Acute ureteric colic is commonly associated with severe and debilitating pain. Theoretically, increasing fluid flow through the affected kidney might expedite stone passage, thereby improving symptoms more quickly. The efficacy and safety of interventions such as high volume intravenous (IV) or oral fluids and diuretics aimed at expediting ureteric stone passage is, however, uncertain. To look at the benefits and harms of diuretics and high volume (above maintenance) IV or oral fluid therapy for treating adult patients presenting with uncomplicated acute ureteric colic. We searched the Cochrane Renal Group's specialised register (3 January 2012). Previously we searched the Cochrane Central Register of Controlled Trials (CENTRAL The Cochrane Library), MEDLINE (from 1966), EMBASE (from 1980) and handsearched reference lists of nephrology and urology textbooks, review articles, relevant studies, and abstracts from nephrology scientific meetings. All randomised controlled trials (RCTs) and quasi-RCTs (including the first period of randomised cross-over studies) looking at diuretics or high volume IV or oral fluids for treating uncomplicated acute ureteric colic in adult patients presenting to the emergency department for the first time during that episode were included. Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model for multiple studies of the same outcomes, otherwise the fixed-effect model was used. Results were expressed as risk ratios (RR) for dichotomous outcomes or as mean differences (MD) for continuous data with 95% confidence intervals (CI). Two studies (enrolling 118 participants) examined the association between intense hydration and ureteric colic outcomes. There was no significant difference in pain at six hours (1 study, 60 participants: RR 1.06, 95% CI 0.71 to 1.57), surgical stone removal (1 study, 60 participants: RR 1.20, 95% CI 0.41 to 3.51) or manipulation by cystoscopy (1 study, 60 participants: RR 0.67, 95% CI 0.21 to 2.13) when no fluids over six hours was compared to three litres IV fluids administered over a six hour period. There was no difference in stone clearance (1 study 43 participants: RR 1.38, 95% CI 0.50 to 3.84), hourly pain score or patients' narcotic requirements (P > 0.05 for all comparisons) when forced IV hydration of two litres over four hours was compared with minimal IV hydration at 20 mL/hour.One study did not provide any details which would have allowed us to assess any of the risk of bias items (selection, detection, performance, attrition or reporting bias). The second study did not report the method of randomisation or allocation (selection bias - unclear), they reported that the patients were blinded to therapy (low risk of bias), analgesics were administered according to predetermined pain score criteria (low risk), and assessment of stone passage was unlikely to have been biased by knowledge of group assignment (low risk). However the second study also reported a high percentage of participants excluded post randomisation (26%; high risk of bias). We were unable to assess or ascertain any of the other risk of bias items. We found no reliable evidence in the literature to support the use of diuretics and high volume fluid therapy for people with acute ureteric colic. However, given the potential positive therapeutic impact of fluids and diuretics to facilitate stone passage, the capacity of these interventions warrants further investigation to determine safety and efficacy profiles.
Inhaled mannitol for cystic fibrosis.

PubMed

Nolan, Sarah J; Thornton, Judith; Murray, Clare S; Dwyer, Tiffany

2015-10-09

Several agents are used to clear secretions from the airways of people with cystic fibrosis. Inhaled dry powder mannitol is now available in Australia and some countries in Europe. The exact mechanism of action of mannitol is unknown, but it increases mucociliary clearance. Phase III trials of inhaled dry powder mannitol for the treatment of cystic fibrosis have been completed. The dry powder formulation of mannitol may be more convenient and easier to use compared with established agents which require delivery via a nebuliser. To assess whether inhaled dry powder mannitol is well tolerated, whether it improves the quality of life and respiratory function in people with cystic fibrosis and which adverse events are associated with the treatment. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic databases, handsearching relevant journals and abstracts from conferences.Date of last search: 16 April 2015. All randomised controlled studies comparing mannitol with placebo, active inhaled comparators (for example, hypertonic saline or dornase alfa) or with no treatment. Authors independently assessed studies for inclusion, carried out data extraction and assessed the risk of bias in included studies. The searches identified nine separate studies (45 publications), of which four studies (36 publications) were included with a total of 667 participants, one study (only available as an abstract) is awaiting assessment and two studies are ongoing. Duration of treatment in the included studies ranged from two weeks to six months with open-label treatment for an additional six months in two of the studies. Three studies compared mannitol with control (a very low dose of mannitol or non-respirable mannitol); two of these were parallel studies with a similar design and data could be pooled, where data for a particular outcome and time point were available; also, one short-term cross-over study supplied additional results. The fourth study compared mannitol to dornase alfa alone and to mannitol plus dornase alfa. There was generally a low risk of bias in relation to randomisation and blinding; evidence from the parallel studies was judged to be of low to moderate quality and from the cross-over studies was judged to be of low to very low quality. While the published papers did not provide all the data required for our analysis, additional unpublished data were provided by the drug's manufacturer and the author of one of the studies. There was an initial test to see if participants tolerated mannitol, with only those who could tolerate the drug being randomised to the studies; therefore the study results are not applicable to the cystic fibrosis population as a whole.For the comparison of mannitol and control, we found no consistent differences in health-related quality of life in any of the domains, except for burden of treatment, which was less for mannitol up to four months in the two pooled studies of a similar design; this difference was not maintained at six months. Up to and including six months, lung function in terms of forced expiratory volume at one second (millilitres) and per cent predicted were significantly improved in all three studies comparing mannitol to control. Beneficial results were observed in these studies in adults and in both concomitant dornase alfa users and non users. A significant reduction was shown in the incidence of pulmonary exacerbations in favour of mannitol at six months; however, the estimate of this effect was imprecise so it is unclear whether the effect is clinically meaningful. Cough, haemoptysis, bronchospasm, pharyngolaryngeal pain and post-tussive vomiting were the most commonly reported side effects on both treatments. Mannitol was not associated with any increase in isolation of bacteria over a six-month period.In the 12-week cross-over study (28 participants), no significant differences were found in the recorded domains of health-related quality of life or measures of lung function between mannitol versus dornase alfa alone and versus mannitol plus dornase alfa. There seemed to be a higher rate of pulmonary exacerbations in the mannitol plus dornase alfa arm compared with dornase alfa alone; although not statistically significant, this was the most common reason for stopping treatment in this arm. Cough was the most common side effect in the mannitol alone arm but there was no occurrence of cough in the dornase alfa alone arm and the most commonly reported reason of withdrawal from the mannitol plus dornase alfa arm was pulmonary exacerbations. Mannitol (with or without dornase alfa) was not associated with any increase in isolation of bacteria over the 12-week period. There is evidence to show that treatment with mannitol over a six-month period is associated with an improvement in some measures of lung function in people with cystic fibrosis compared to control. There is no evidence that quality of life is improved for participants taking mannitol compared to control; a decrease in burden of treatment was observed up to four months on mannitol compared to control but this difference was not maintained to six months. Randomised information regarding the burden of adding mannitol to an existing treatment is limited. There is no randomised evidence of improvement in lung function or quality of life comparing mannitol to dornase alfa alone and to mannitol plus dornase alfa.Mannitol as a single or concomitant treatment to dornase alfa may be of benefit to people with cystic fibrosis, but further research is required in order to establish who may benefit most and whether this benefit is sustained in the longer term.The clinical implications from this review suggest that mannitol could be considered as a treatment in cystic fibrosis; however, studies comparing its efficacy against other (established) mucolytic therapies need to be undertaken before it can be considered for mainstream practice.
Rip Current Velocity Structure in Drifter Trajectories and Numerical Simulations

NASA Astrophysics Data System (ADS)

Schmidt, W. E.; Slinn, D. N.

2008-12-01

Estimates of rip current velocity and cross-shore structure were made using surfzone drifters, bathymetric surveys, and rectified video images. Over 60 rip current trajectories were observed during a three year period at a Southern California beach in July 2000, 2001, and 2002. Incident wave heights (Hs) immediately offshore (~7 m depth) were obtained by initializing a refraction model with data from nearby directional wave buoys, and varied from 0.3 to 1.0 m. Tide levels varied over approximately 1 m and winds were light. Numerical simulations using the non-linear shallow water equations and modeled over measured bathymetry also produced similar flows and statistics. Time series of drifter position, sampled at 1 Hz, were first-differenced to produce velocity time series. Maximum observed velocities varied between 25 and 80 cm s-1, whereas model maximum velocities were lower by a factor 2 to 3. When velocity maxima were non-dimensionalized by respective trajectory mean velocity, both observed and modeled values varied between 1.5 and 3.5. Cross-shore location of rip current velocity maxima for both shore-normal and shore-oblique rip currents were strongly coincident with the surfzone edge (Xb), as determined by rectified video (observations) or breakpoint (model). Once outside of the surfzone, observed and modeled rip current velocities decreased to 10% of their peak values within 2 surfzone widths of the shoreline, a useful definition of rip current cross-shore extent.
Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

NASA Astrophysics Data System (ADS)

Mehran, A.; AghaKouchak, A.; Phillips, T. J.

2014-02-01

The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies, and biases for both entire distributions and their upper tails. The results of the volumetric hit index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas but that their replication of observed precipitation over arid regions and certain subcontinental regions (e.g., northern Eurasia, eastern Russia, and central Australia) is problematical. Overall, the VHI of the multimodel ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and Central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g., western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, intermodel variations in bias over Australia and Amazonia are considerable. The quantile bias analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. It is found that a simple mean field bias removal improves the overall B and VHI values but does not make a significant improvement at high quantiles of precipitation.
Pharmacological interventions for sleepiness and sleep disturbances caused by shift work.

PubMed

Liira, Juha; Verbeek, Jos H; Costa, Giovanni; Driscoll, Tim R; Sallinen, Mikael; Isotalo, Leena K; Ruotsalainen, Jani H

2015-02-01

Shift work results in sleep-wake disturbances, which cause sleepiness during night shifts and reduce sleep length and quality in daytime sleep after the night shift. In its serious form it is also called shift work sleep disorder. Various pharmacological products are used to ameliorate symptoms of sleepiness or poor sleep length and quality. To evaluate the effects of pharmacological interventions to reduce sleepiness or to improve alertness at work and decrease sleep disturbances whilst of work, or both, in workers undertaking shift work. We searched CENTRAL, MEDLINE, EMBASE, PubMed and PsycINFO up to 20 September 2013 and ClinicalTrials.gov up to July 2013. We also screened reference lists of included trials and relevant reviews. We included all eligible randomised controlled trials (RCTs), including cross-over RCTs, of pharmacological products among workers who were engaged in shift work (including night shifts) in their present jobs and who may or may not have had sleep problems. Primary outcomes were sleep length and sleep quality while of work, alertness and sleepiness, or fatigue at work. Two authors independently selected studies, extracted data and assessed risk of bias in included trials. We performed meta-analyses where appropriate. We included 15 randomised placebo-controlled trials with 718 participants. Nine trials evaluated the effect of melatonin and two the effect of hypnotics for improving sleep problems. One trial assessed the effect of modafinil, two of armodafinil and one examined caffeine plus naps to decrease sleepiness or to increase alertness.
Simulation-based team training for multi-professional obstetric care teams to improve patient outcome: a multicentre, cluster randomised controlled trial.

PubMed

Fransen, A F; van de Ven, J; Schuit, E; van Tetering, Aac; Mol, B W; Oei, S G

2017-03-01

To investigate whether simulation-based obstetric team training in a simulation centre improves patient outcome. Multicentre, open, cluster randomised controlled trial. Obstetric units in the Netherlands. Women with a singleton pregnancy beyond 24 weeks of gestation. Random allocation of obstetric units to a 1-day, multi-professional, simulation-based team training focusing on crew resource management (CRM) in a simulation centre or to no such team training. Intention-to-treat analyses were performed at the cluster level, including a measurement 1 year prior to the intervention. Primary outcome was a composite outcome of obstetric complications during the first year post-intervention, including low Apgar score, severe postpartum haemorrhage, trauma due to shoulder dystocia, eclampsia and hypoxic-ischaemic encephalopathy. Maternal and perinatal mortality were also registered. Each study group included 12 units with a median unit size of 1224 women, combining for a total of 28 657 women. In total, 471 medical professionals received the training course. The composite outcome of obstetric complications did not differ between study groups [odds ratio (OR) 1.0, 95% confidence interval (CI) 0.80-1.3]. Team training reduced trauma due to shoulder dystocia (OR 0.50, 95% CI 0.25-0.99) and increased invasive treatment for severe postpartum haemorrhage (OR 2.2, 95% CI 1.2-3.9) compared with no intervention. Other outcomes did not differ between study groups. A 1-day, off-site, simulation-based team training, focusing on teamwork skills, did not reduce a composite of obstetric complications. 1-day, off-site, simulation-based team training did not reduce a composite of obstetric complications. © 2016 Royal College of Obstetricians and Gynaecologists.
Preventing substance misuse: study protocol for a randomised controlled trial of the Strengthening Families Programme 10–14 UK (SFP 10–14 UK)

PubMed Central

2014-01-01

Background Prevention of alcohol, drug and tobacco misuse by young people is a key public health priority. There is a need to develop the evidence base through rigorous evaluations of innovative approaches to substance misuse prevention. The Strengthening Families Programme 10–14 is a universal family-based alcohol, drugs and tobacco prevention programme, which has achieved promising results in US trials, and which now requires cross-cultural assessment. This paper therefore describes the protocol for a randomised controlled trial of the UK version of the Strengthening Families Programme 10–14 (SFP 10–14 UK). Methods/Design The trial comprises a pragmatic cluster randomised controlled effectiveness trial with families as the unit of randomisation, with embedded process and economic evaluations. Participating families will be randomised to one of two treatment groups - usual care with full access to existing services (control group), or usual care plus SFP 10–14 UK (intervention group). The trial has two primary outcomes - the number of occasions that young people report having drunk alcohol in the last 30 days, and drunkenness during the last 30 days, both dichotomised as ‘never’ and ‘1-2 times or more’. The main follow-up is at 2 years past baseline, and short-term and intermediate outcomes are also measured at 9 and 15 months. Discussion The results from this trial will provide evidence on the effectiveness and cost-effectiveness of an innovative universal family-based substance misuse prevention programme in a UK context. Trial registration Current Controlled Trials ISRCTN63550893. PMID:24438460
Effects of cross-linking on partitioning of nanoparticles into a polymer brush: Coarse-grained simulations test simple approximate theories

NASA Astrophysics Data System (ADS)

Ozmaian, Masoumeh; Jasnow, David; Eskandari Nasrabad, Afshin; Zilman, Anton; Coalson, Rob D.

2018-01-01

The effect of cohesive contacts or, equivalently, dynamical cross-linking on the equilibrium morphology of a polymer brush infiltrated by nanoparticles that are attracted to the polymer strands is studied for plane-grafted brushes using coarse-grained molecular dynamics and approximate statistical mechanical models. In particular, the Alexander-de Gennes (AdG) and Strong Stretching Theory (SST) mean-field theory (MFT) models are considered. It is found that for values of the MFT cross-link strength interaction parameter beyond a certain threshold, both AdG and SST models predict that the polymer brush will be in a compact state of nearly uniform density packed next to the grafting surface over a wide range of solution phase nanoparticle concentrations. Coarse grained molecular dynamics simulations confirm this prediction, for both small nanoparticles (nanoparticle volume = monomer volume) and large nanoparticles (nanoparticle volume = 27 × monomer volume). Simulation results for these cross-linked systems are compared with analogous results for systems with no cross-linking. At the same solution phase nanoparticle concentration, strong cross-linking results in additional compression of the brush relative to the non-crosslinked analog and, at all but the lowest concentrations, to a lesser degree of infiltration by nanoparticles. For large nanoparticles, the monomer density profiles show clear oscillations moving outwards from the grafting surface, corresponding to a degree of layering of the absorbed nanoparticles in the brush as they pack against the grafting surface.
The effectiveness of crisis resource management and team debriefing in resuscitation education of nursing students: A randomised controlled trial.

PubMed

Coppens, Imgard; Verhaeghe, Sofie; Van Hecke, Ann; Beeckman, Dimitri

2018-01-01

The aim of this study was to investigate (i) whether integrating a course on crisis resource management principles and team debriefings in simulation training, increases self-efficacy, team efficacy and technical skills of nursing students in resuscitation settings and (ii) which phases contribute the most to these outcomes. Crisis resource management principles have been introduced in health care to optimise teamwork. Simulation training offers patient safe training opportunities. There is evidence that simulation training increases self-efficacy and team efficacy but the contribution of the different phases like crisis resource management principles, simulation training and debriefing on self-efficacy, team efficacy and technical skills is not clear. Randomised controlled trial in a convenience sample (n = 116) in Belgium. Data were collected between February 2015-April 2015. Participants in the intervention group (n = 60) completed a course on crisis resource management principles, followed by a simulation training session, a team debriefing and a second simulation training session. Participants in the control group (n = 56) only completed two simulation training sessions. The outcomes self-efficacy, team efficacy and technical skills were assessed after each simulation training. An ancillary analysis of the learning effect was conducted. The intervention group increased on self-efficacy (2.13%, p = .02) and team efficacy (9.92%, p < .001); the control group only increased significantly on team efficacy (4.5%, p = .001). The intervention group scored significantly higher on team efficacy (8.49%, p < .001) compared to the control group. Combining crisis resource management principles and team debriefings in simulation training increases self-efficacy and team efficacy. The debriefing phase contributes the most to these effects. By partnering with healthcare settings, it becomes possible to offer interdisciplinary simulation training that can increase patient safety. © 2017 John Wiley & Sons Ltd.
Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

DOE PAGES

Mehran, Ali; AghaKouchak, Amir; Phillips, Thomas J.

2014-02-25

Numerous studies have emphasized that climate simulations are subject to various biases and uncertainties. The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies and biases for both entire data distributions and their upper tails. The results of the Volumetric Hit Index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas, but that their replication of observed precipitation over arid regions and certain sub-continentalmore » regions (e.g., northern Eurasia, eastern Russia, central Australia) is problematical. Overall, the VHI of the multi-model ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (e.g., the 75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g. western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, inter-model variations in bias over Australia and Amazonia are considerable. The Quantile Bias (QB) analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. Lastly, we found that a simple mean-field bias removal improves the overall B and VHI values, but does not make a significant improvement in these model performance metrics at high quantiles of precipitation.« less
Exercise for depression in care home residents: a randomised controlled trial with cost-effectiveness analysis (OPERA).

PubMed

Underwood, M; Lamb, S E; Eldridge, S; Sheehan, B; Slowther, A; Spencer, A; Thorogood, M; Atherton, N; Bremner, S A; Devine, A; Diaz-Ordaz, K; Ellard, D R; Potter, R; Spanjers, K; Taylor, S J C

2013-05-01

Many older people living in care homes (long term residential care or nursing homes) are depressed. Exercise is a promising non-drug intervention for preventing and treating depression in this population. To evaluate the impact of a 'whole-home' intervention, consisting of training for residential and nursing home staff backed up with a twice-weekly, physiotherapist-led exercise class on depressive symptoms in care home residents. A cluster randomised controlled trial with a cost-effectiveness analysis to compare (1) the prevalence of depression in intervention homes with that in control homes in all residents contributing data 12 months after homes were randomised (cross-sectional analysis); (2) the number of depressive symptoms at 6 months between intervention and control homes in residents who were depressed at pre-randomisation baseline assessment (depressed cohort comparison); and (3) the number of depressive symptoms at 12 months between intervention and control homes in all residents who were present at pre-randomisation baseline assessment (cohort comparison). Seventy-eight care homes in Coventry and Warwickshire and north-east London. Care home residents aged ≥ 65 years. Control intervention: Depression awareness training programme for care home staff. Active intervention: A 'whole-home' exercise intervention, consisting of training for care home staff backed up with a twice-weekly, physiotherapist-led exercise group. Geriatric Depression Scale-15, proxy European Quality of Life-5 Dimensions (EQ-5D), cost-effectiveness from an National Health Service perspective, peripheral fractures and death. We recruited a total of 1054 participants. Cross-sectional analysis: We obtained 595 Geriatric Depression Scale-15 scores and 724 proxy EQ-5D scores. For the cohort analyses we obtained 765 baseline Geriatric Depression Scale-15 scores and 776 proxy EQ-5D scores. Of the 781 who we assessed prior to randomisation, 765 provided a Geriatric Depression Scale-15 score. Of these 374 (49%) were depressed and constitute our depressed cohort. Resource-use and quality-adjusted life-year data, based on proxy EQ-5D, were available for 798 residents recruited prior to randomisation. We delivered 3191 group exercise sessions with 31,705 person attendances and an average group size of 10 (5.3 study participants and 4.6 non-study participants). On average, our participants attended around half of the possible sessions. No serious adverse events occurred during the group exercise sessions. In the cross-sectional analysis the odds for being depressed were 0.76 [95% confidence interval (CI) 0.53 to 1.09] lower in the intervention group at 12 months. The point estimates for benefit for both the cohort analysis (0.13, 95% CI -0.33 to 0.60) and depressed cohort (0.22, 95% CI -0.52 to 0.95) favoured the control intervention. There was no evidence of differences in fracture rates or mortality (odds ratio 1.07, 95% CI 0.79 to 1.48) between the two groups. There was no evidence of differences in the other outcomes between the two groups. Economic analysis: The additional National Health Service cost of the OPERA intervention was £374 per participant (95% CI -£655 to £1404); the mean difference in quality-adjusted life-year was -0.0014 (95% CI -0.0728 to 0.0699). The active intervention was thus dominated by the control intervention, which was more effective and less costly. The results do not support the use of a whole-home physical activity and moderate-intensity exercise programme to reduce depression in care home residents. Current Controlled Trials ISRCTN43769277. This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 18. See the Health Technology Assessment programme website for further project information.

An exploratory pilot study to design and assess the credibility of a sham kinesiology treatment.

PubMed

Hall, Sue; Lewith, George; Brien, Sarah; Little, Paul

2008-12-01

Kinesiology is a complementary therapy assessing subtle change in manual muscle testing results to select individualised treatments. We report the exploratory 2-stage development and pilot of a sham kinesiology treatment for use in a clinical trial to evaluate the specific effects of this intervention. 1. To design, pilot and assess the credibility of a sham kinesiology treatment in a kinesiology-aware population. 2. To pilot the sham kinesiology in a cross-over study of sham versus real kinesiology, and to make an exploratory assessment of its credibility in a kinesiology-naïve population. 1. 10 kinesiology-aware volunteers received a specially designed sham treatment weekly for 5 weeks which was subject to a credibility assessment. 2. 10 kinesiology-naïve patients with low back pain were randomised to receive 4 real and 4 sham treatments in a cross-over design; the treatments were subject to a credibility assessment. 100% of participants found the sham protocol a credible treatment as measured by the credibility questionnaire. 100% of patients having real treatment first did not recognise that the second set of treatments were sham. Small numbers precluded the use of formal statistical tests. In this small sample it appeared feasible to deliver an apparently credible sham kinesiology treatment. This feasibility study has allowed us to develop a sham treatment for use in a larger prospective clinical trial of kinesiology in patients with low back pain. 2008 S. Karger AG, Basel.
Excitation of vibrational quanta in furfural by intermediate-energy electrons

NASA Astrophysics Data System (ADS)

Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; Blanco, F.; Brunger, M. J.

2015-12-01

We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.
Intra-aortic balloon pump counterpulsation (IABP) for myocardial infarction complicated by cardiogenic shock.

PubMed

Unverzagt, Susanne; Buerke, Michael; de Waha, Antoinette; Haerting, Johannes; Pietzner, Diana; Seyfarth, Melchior; Thiele, Holger; Werdan, Karl; Zeymer, Uwe; Prondzinsky, Roland

2015-03-27

Intra-aortic balloon pump counterpulsation (IABP) is currently the most commonly used mechanical assist device for patients with cardiogenic shock due to acute myocardial infarction. Although there has been only limited evidence from randomised controlled trials, the previous guidelines of the American Heart Association/American College of Cardiology (AHA/ACC) and the European Society of Cardiology (ESC) strongly recommended the use of the IABP in patients with infarction-related cardiogenic shock on the basis of pathophysiological considerations, non-randomised trials and registry data. The recent guidelines downgraded the recommendation based on a meta-analysis which could only include non-randomised trials showing conflicting results. Up to now, there have been no guideline recommendations and no actual meta-analysis including the results of the large randomised multicentre IABP-SHOCK II Trial which showed no survival benefit with IABP support. This systematic review is an update of the review published in 2011. To evaluate, in terms of efficacy and safety, the effect of IABP versus non-IABP or other assist devices guideline compliant standard therapy on mortality and morbidity in patients with acute myocardial infarction complicated by cardiogenic shock. Searches of CENTRAL, MEDLINE (Ovid) and EMBASE (Ovid), LILACS, IndMed and KoreaMed, registers of ongoing trials and proceedings of conferences were updated in October 2013. Reference lists were scanned and experts in the field contacted to obtain further information. No language restrictions were applied. Randomised controlled trials on patients with acute myocardial infarction complicated by cardiogenic shock. Data collection and analysis were performed according to the published protocol. Individual patient data were provided for six trials and merged with aggregate data. Summary statistics for the primary endpoints were hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs). Seven eligible studies were identified from a total of 2314 references. One new study with 600 patients was added to the original review. Four trials compared IABP to standard treatment and three to other percutaneous left assist devices (LVAD). Data from a total of 790 patients with acute myocardial infarction and cardiogenic shock were included in the updated meta-analysis: 406 patients were treated with IABP and 384 patients served as controls; 339 patients were treated without assisting devices and 45 patients with other LVAD. The HR for all-cause 30-day mortality of 0.95 (95% CI 0.76 to 1.19) provided no evidence for a survival benefit. Different non-fatal cardiovascular events were reported in five trials. During hospitalisation, 11 and 4 out of 364 patients from the intervention groups suffered from reinfarction or stroke, respectively. Altogether 5 out of 363 patients from the control group suffered from reinfarction or stroke. Reocclusion was treated with subsequent re-revascularization in 6 out of 352 patients from the intervention group and 13 out of 353 patients of the control group. The high incidence of complications such as moderate and severe bleeding or infection in the control groups has to be attributed to interventions with other LVAD. Possible reasons for bias were more frequent in small studies with high cross-over rates, early stopping and the inclusion of patients with IABP at randomisation. Available evidence suggests that IABP may have a beneficial effect on some haemodynamic parameters. However, this did not result in survival benefits so there is no convincing randomised data to support the use of IABP in infarct-related cardiogenic shock.
Methods for a Rapid Systematic Review and Metaanalysis in Evaluating Selective Serotonin Reuptake Inhibitors for Premature Ejaculation

ERIC Educational Resources Information Center

Martyn-St. James, Marrissa; Cooper, Katy; Kaltenthaler, Eva

2017-01-01

The aim of this study was to evaluate a rapid systematic review method in which randomised controlled trial (RCT) data was extracted from existing reviews and subsequent RCTs. The method enabled: identification of RCTs not included by existing reviews; cross-checking RCT data for consistency where there was more than one review; double data…
Reasons for non-recruitment of eligible patients to a randomised controlled trial of secondary prevention after intracerebral haemorrhage: observational study.

PubMed

Maxwell, Amy E; MacLeod, Mary Joan; Joyson, Anu; Johnson, Sharon; Ramadan, Hawraman; Bellfield, Ruth; Byrne, Anthony; McGhee, Caroline; Rudd, Anthony; Price, Fiona; Vasileiadis, Evangelos; Holden, Melinda; Hewitt, Jonathan; Carpenter, Michael; Needle, Ann; Valentine, Stacey; Patel, Farzana; Harrington, Frances; Mudd, Paul; Emsley, Hedley; Gregary, Bindu; Kane, Ingrid; Muir, Keith; Tiwari, Divya; Owusu-Agyei, Peter; Temple, Natalie; Sekaran, Lakshmanan; Ragab, Suzanne; England, Timothy; Hedstrom, Amanda; Jones, Phil; Jones, Sarah; Doherty, Mandy; McCarron, Mark O; Cohen, David L; Tysoe, Sharon; Al-Shahi Salman, Rustam

2017-04-05

Recruitment to randomised prevention trials is challenging, not least for intracerebral haemorrhage (ICH) associated with antithrombotic drug use. We investigated reasons for not recruiting apparently eligible patients at hospital sites that keep screening logs in the ongoing REstart or STop Antithrombotics Randomised Trial (RESTART), which seeks to determine whether to start antiplatelet drugs after ICH. By the end of May 2015, 158 participants had been recruited at 108 active sites in RESTART. The trial coordinating centre invited all sites that kept screening logs to submit screening log data, followed by one reminder. We checked the integrity of data, focused on the completeness of data about potentially eligible patients and categorised the reasons they were not randomised. Of 108 active sites, 39 (36%) provided usable screening log data over a median of ten (interquartile range = 5-13) months of recruitment per site. During this time, sites screened 633 potentially eligible patients and randomised 53 (8%) of them. The main reasons why 580 patients were not randomised were: 43 (7%) patients started anticoagulation, 51 (9%) patients declined, 148 (26%) patients' stroke physicians were not uncertain about using antiplatelet drugs, 162 (28%) patients were too unwell and 176 (30%) patients were not randomised due to other reasons. RESTART recruited ~8% of eligible patients. If more physicians were uncertain about the therapeutic dilemma that RESTART is addressing, RESTART could have recruited up to four times as many participants. The trial coordinating centre continues to engage with physicians about their uncertainty. EU Clinical Trials, EudraCT 2012-003190-26 . Registered on 3 July 2012.
Simulations of fully deformed oscillating flux tubes

NASA Astrophysics Data System (ADS)

Karampelas, K.; Van Doorsselaere, T.

2018-02-01

Context. In recent years, a number of numerical studies have been focusing on the significance of the Kelvin-Helmholtz instability in the dynamics of oscillating coronal loops. This process enhances the transfer of energy into smaller scales, and has been connected with heating of coronal loops, when dissipation mechanisms, such as resistivity, are considered. However, the turbulent layer is expected near the outer regions of the loops. Therefore, the effects of wave heating are expected to be confined to the loop's external layers, leaving their denser inner parts without a heating mechanism. Aim. In the current work we aim to study the spatial evolution of wave heating effects from a footpoint driven standing kink wave in a coronal loop. Methods: Using the MPI-AMRVAC code, we performed ideal, three dimensional magnetohydrodynamic simulations of footpoint driven transverse oscillations of a cold, straight coronal flux tube, embedded in a hotter environment. We have also constructed forward models for our simulation using the FoMo code. Results: The developed transverse wave induced Kelvin-Helmholtz (TWIKH) rolls expand throughout the tube cross-section, and cover it entirely. This turbulence significantly alters the initial density profile, leading to a fully deformed cross section. As a consequence, the resistive and viscous heating rate both increase over the entire loop cross section. The resistive heating rate takes its maximum values near the footpoints, while the viscous heating rate at the apex. Conclusions: We conclude that even a monoperiodic driver can spread wave heating over the whole loop cross section, potentially providing a heating source in the inner loop region. Despite the loop's fully deformed structure, forward modelling still shows the structure appearing as a loop. A movie attached to Fig. 1 is available at http://https://www.aanda.org
Immediate chest X-ray for patients at risk of lung cancer presenting in primary care: randomised controlled feasibility trial

PubMed Central

Neal, Richard D; Barham, Allan; Bongard, Emily; Edwards, Rhiannon Tudor; Fitzgibbon, Jim; Griffiths, Gareth; Hamilton, Willie; Hood, Kerenza; Nelson, Annmarie; Parker, David; Porter, Cath; Prout, Hayley; Roberts, Kirsty; Rogers, Trevor; Thomas-Jones, Emma; Tod, Angela; Yeo, Seow Tien; Hurt, Chris N

2017-01-01

Background: Achieving earlier stage diagnosis is one option for improving lung cancer outcomes in the United Kingdom. Patients with lung cancer typically present with symptoms to general practitioners several times before referral or investigation. Methods: We undertook a mixed methods feasibility individually randomised controlled trial (the ELCID trial) to assess the feasibility and inform the design of a definitive, fully powered, UK-wide, Phase III trial of lowering the threshold for urgent investigation of suspected lung cancer. Patients over 60, with a smoking history, presenting with new chest symptoms to primary care, were eligible to be randomised to intervention (urgent chest X-ray) or usual care. Results: The trial design and materials were acceptable to GPs and patients. We randomised 255 patients from 22 practices, although the proportion of eligible patients who participated was lower than expected. Survey responses (89%), and the fidelity of the intervention (82% patients X-rayed within 3 weeks) were good. There was slightly higher anxiety and depression in the control arm in participants aged >75. Three patients (1.2%) were diagnosed with lung cancer. Conclusions: We have demonstrated the feasibility of individually randomising patients at higher risk of lung cancer, to a trial offering urgent investigation or usual care. PMID:28072761
Physical models, cross sections, and numerical approximations used in MCNP and GEANT4 Monte Carlo codes for photon and electron absorbed fraction calculation.

PubMed

Yoriyaz, Hélio; Moralles, Maurício; Siqueira, Paulo de Tarso Dalledone; Guimarães, Carla da Costa; Cintra, Felipe Belonsi; dos Santos, Adimir

2009-11-01

Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most of them used Monte Carlo radiation transport codes. Despite the widespread use of these codes due to the variety of resources and potentials they offered to carry out dose calculations, several aspects like physical models, cross sections, and numerical approximations used in the simulations still remain an object of study. Accurate dose estimate depends on the correct selection of a set of simulation options that should be carefully chosen. This article presents an analysis of several simulation options provided by two of the most used codes worldwide: MCNP and GEANT4. For this purpose, comparisons of absorbed fraction estimates obtained with different physical models, cross sections, and numerical approximations are presented for spheres of several sizes and composed as five different biological tissues. Considerable discrepancies have been found in some cases not only between the different codes but also between different cross sections and algorithms in the same code. Maximum differences found between the two codes are 5.0% and 10%, respectively, for photons and electrons. Even for simple problems as spheres and uniform radiation sources, the set of parameters chosen by any Monte Carlo code significantly affects the final results of a simulation, demonstrating the importance of the correct choice of parameters in the simulation.
A case report of evaluating a large-scale health systems improvement project in an uncontrolled setting: a quality improvement initiative in KwaZulu-Natal, South Africa.

PubMed

Mate, Kedar S; Ngidi, Wilbroda Hlolisile; Reddy, Jennifer; Mphatswe, Wendy; Rollins, Nigel; Barker, Pierre

2013-11-01

New approaches are needed to evaluate quality improvement (QI) within large-scale public health efforts. This case report details challenges to large-scale QI evaluation, and proposes solutions relying on adaptive study design. We used two sequential evaluative methods to study a QI effort to improve delivery of HIV preventive care in public health facilities in three districts in KwaZulu-Natal, South Africa, over a 3-year period. We initially used a cluster randomised controlled trial (RCT) design. During the RCT study period, tensions arose between intervention implementation and evaluation design due to loss of integrity of the randomisation unit over time, pressure to implement changes across the randomisation unit boundaries, and use of administrative rather than functional structures for the randomisation. In response to this loss of design integrity, we switched to a more flexible intervention design and a mixed-methods quasiexperimental evaluation relying on both a qualitative analysis and an interrupted time series quantitative analysis. Cluster RCT designs may not be optimal for evaluating complex interventions to improve implementation in uncontrolled 'real world' settings. More flexible, context-sensitive evaluation designs offer a better balance of the need to adjust the intervention during the evaluation to meet implementation challenges while providing the data required to evaluate effectiveness. Our case study involved HIV care in a resource-limited setting, but these issues likely apply to complex improvement interventions in other settings.
Meiotic gene-conversion rate and tract length variation in the human genome.

PubMed

Padhukasahasram, Badri; Rannala, Bruce

2013-02-27

Meiotic recombination occurs in the form of two different mechanisms called crossing-over and gene-conversion and both processes have an important role in shaping genetic variation in populations. Although variation in crossing-over rates has been studied extensively using sperm-typing experiments, pedigree studies and population genetic approaches, our knowledge of variation in gene-conversion parameters (ie, rates and mean tract lengths) remains far from complete. To explore variability in population gene-conversion rates and its relationship to crossing-over rate variation patterns, we have developed and validated using coalescent simulations a comprehensive Bayesian full-likelihood method that can jointly infer crossing-over and gene-conversion rates as well as tract lengths from population genomic data under general variable rate models with recombination hotspots. Here, we apply this new method to SNP data from multiple human populations and attempt to characterize for the first time the fine-scale variation in gene-conversion parameters along the human genome. We find that the estimated ratio of gene-conversion to crossing-over rates varies considerably across genomic regions as well as between populations. However, there is a great degree of uncertainty associated with such estimates. We also find substantial evidence for variation in the mean conversion tract length. The estimated tract lengths did not show any negative relationship with the local heterozygosity levels in our analysis.European Journal of Human Genetics advance online publication, 27 February 2013; doi:10.1038/ejhg.2013.30.
A pilot randomised double blind controlled trial of the efficacy of purified fatty acids for the treatment of women with endometriosis-associated pain (PurFECT): study protocol.

PubMed

Abokhrais, Ibtisam M; Saunders, Philippa T K; Denison, Fiona C; Doust, Ann; Williams, Linda; Horne, Andrew W

2018-01-01

Endometriosis affects 6-10% of women and is associated with debilitating pelvic pain. It costs the UK > £2.8 billion per year in loss of productivity. Endometriosis can be managed by surgical excision or medically by ovarian suppression. However, ~ 75% symptoms recur after surgery and available medical treatments have undesirable side effects and are contraceptive. Omega-3 purified fatty acids (PUFA) have been shown in animal models to reduce factors that are thought to lead to endometriosis-associated pain, have minimal side effects, and no effects on fertility. This paper presents a protocol for a two-arm, pilot parallel randomised controlled trial (RCT) which aims to inform the planning of a future multicentre trial to evaluate the efficacy of Omega-3 PUFA in the management of endometriosis-associated pain in women. The study will recruit women with endometriosis over a 12-month period in the National Health Service (NHS) Lothian, UK, and randomise them to 8 weeks of treatment with Omega-3 PUFA or comparator (olive oil). The primary objective is to assess recruitment and retention rates. The secondary objectives are to determine the effectiveness/acceptability to participants of the proposed methods of recruitment/randomisation/treatments/questionnaires, to inform the sample size calculation and to refine the research methodology for a future large randomised controlled trial. Response to treatment will be monitored by pain scores and questionnaires assessing physical and emotional function compared at baseline and 8 weeks. We recognise that there may be potential difficulties in mounting a large randomised controlled trial for endometriosis to assess Omega-3 PUFA because they are a dietary supplement readily available over the counter and already used by women with endometriosis. We have therefore designed this pilot study to assess practical feasibility and following the 'Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials' recommendations for the design of chronic pain trials. ISRCTN44202346.
A study of internal energy relaxation in shocks using molecular dynamics based models

NASA Astrophysics Data System (ADS)

Li, Zheng; Parsons, Neal; Levin, Deborah A.

2015-10-01

Recent potential energy surfaces (PESs) for the N2 + N and N2 + N2 systems are used in molecular dynamics (MD) to simulate rates of vibrational and rotational relaxations for conditions that occur in hypersonic flows. For both chemical systems, it is found that the rotational relaxation number increases with the translational temperature and decreases as the rotational temperature approaches the translational temperature. The vibrational relaxation number is observed to decrease with translational temperature and approaches the rotational relaxation number in the high temperature region. The rotational and vibrational relaxation numbers are generally larger in the N2 + N2 system. MD-quasi-classical trajectory (QCT) with the PESs is also used to calculate the V-T transition cross sections, the collision cross section, and the dissociation cross section for each collision pair. Direct simulation Monte Carlo (DSMC) results for hypersonic flow over a blunt body with the total collision cross section from MD/QCT simulations, Larsen-Borgnakke with new relaxation numbers, and the N2 dissociation rate from MD/QCT show a profile with a decreased translational temperature and a rotational temperature close to vibrational temperature. The results demonstrate that many of the physical models employed in DSMC should be revised as fundamental potential energy surfaces suitable for high temperature conditions become available.
On the enhanced sampling over energy barriers in molecular dynamics simulations.

PubMed

Gao, Yi Qin; Yang, Lijiang

2006-09-21

We present here calculations of free energies of multidimensional systems using an efficient sampling method. The method uses a transformed potential energy surface, which allows an efficient sampling of both low and high energy spaces and accelerates transitions over barriers. It allows efficient sampling of the configuration space over and only over the desired energy range(s). It does not require predetermined or selected reaction coordinate(s). We apply this method to study the dynamics of slow barrier crossing processes in a disaccharide and a dipeptide system.
A cross-assessment of CCI-ECVs and RCSM simulations over the Mediterranean area

NASA Astrophysics Data System (ADS)

D'Errico, Miriam; Planton, Serge; Nabat, Pierre

2017-04-01

A first objective of this study, conducted in the framework of the Climate Modelling Users Group (CMUG), one of the projects of the European Space Agency Climate Change Initiative (ESA CCI) program, is a cross-assessment of simulations of a Med-CORDEX regional climate system model (CNRM-RCSM5) and a sub-set of atmosphere, marine and surface interrelated Satellite-Derived Essential Climate Variables (CCI-ECVs) (i.e. sea surface temperature, sea level, aerosols and soil moisture content) over the Mediterranean area. The consistency between the model and the CCI-ECVs is evaluated through the analysis of a climate specific event that can be observed with the CCI-ECVs, in atmospheric reanalysis and reproduced in the RCSM simulations. In this presentation we focus on the July 2006 heat wave that affected the western part of the Mediterranean continental and marine area. The application of a spectral nudging method using ERA-Interim reanalysis in our simulation allows to reproduce this event with a proper chronology. As a result we show that the consistency between the simulated model aerosol optical depth and the ECV products (being produced by the ESA Aerosol CCI project consortium) depends on the choice of the algorithm used to infer the variable from the satellite observations. In particular the heat wave main characteristics become consistent between the model and the satellite-derived observations for sea surface temperature, soil moisture and sea level. The link between the atmospheric circulation and the aerosols distribution is also investigated.
Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis

PubMed Central

Buitrago-Lopez, Adriana; Sanderson, Jean; Johnson, Laura; Warnakula, Samantha; Wood, Angela; Di Angelantonio, Emanuele

2011-01-01

Objective To evaluate the association of chocolate consumption with the risk of developing cardiometabolic disorders. Design Systematic review and meta-analysis of randomised controlled trials and observational studies. Data sources Medline, Embase, Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, reference lists of relevant studies to October 2010, and email contact with authors. Study selection Randomised trials and cohort, case-control, and cross sectional studies carried out in human adults, in which the association between chocolate consumption and the risk of outcomes related to cardiometabolic disorders were reported. Data extraction Data were extracted by two independent investigators, and a consensus was reached with the involvement of a third. The primary outcome was cardiometabolic disorders, including cardiovascular disease (coronary heart disease and stroke), diabetes, and metabolic syndrome. A meta-analysis assessed the risk of developing cardiometabolic disorders by comparing the highest and lowest level of chocolate consumption. Results From 4576 references seven studies met the inclusion criteria (including 114 009 participants). None of the studies was a randomised trial, six were cohort studies, and one a cross sectional study. Large variation was observed between these seven studies for measurement of chocolate consumption, methods, and outcomes evaluated. Five of the seven studies reported a beneficial association between higher levels of chocolate consumption and the risk of cardiometabolic disorders. The highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease (relative risk 0.63 (95% confidence interval 0.44 to 0.90)) and a 29% reduction in stroke compared with the lowest levels. Conclusions Based on observational evidence, levels of chocolate consumption seem to be associated with a substantial reduction in the risk of cardiometabolic disorders. Further experimental studies are required to confirm a potentially beneficial effect of chocolate consumption. PMID:21875885
The impact of administration of conjugate vaccines containing cross reacting material on Haemophilus influenzae type b antibody responses in infants: A systematic review and meta-analysis of randomised controlled trials.

PubMed

Voysey, Merryn; Sadarangani, Manish; Clutterbuck, Elizabeth; Bolgiano, Barbara; Pollard, Andrew J

2016-07-25

Protein-polysaccharide conjugate vaccines such as Haemophilus influenzae type b (Hib), meningococcal, and pneumococcal vaccine, induce immunological memory and longer lasting protection than plain polysaccharide vaccines. The most common proteins used as carriers are tetanus toxoid (TT) and cross reacting material-197 (CRM), a mutant form of diphtheria toxoid. CRM conjugate vaccines have been reported to suppress antibody responses to co-administered Hib-TT vaccine. We conducted a systematic review and meta-analysis of randomised controlled trials in which infants were randomised to receive meningococcal or pneumococcal conjugate vaccines along with Hib-TT. Trials of licensed vaccines with different carrier proteins were included for group C meningococcal (MenC), quadrivalent ACWY meningococcal (MenACWY), and pneumococcal vaccines. Twenty-three trials were included in the meta-analyses. Overall, administration of MenC-CRM in a 2 or 3 dose schedule resulted in a 45% reduction in Hib antibody concentrations (GMR 0.55, 95% CI 0.49-0.62). MenACWY-CRM boosted Hib antibody responses by 22% (GMR 1.22, 95% CI 1.06-1.41) whilst pneumococcal CRM conjugate vaccines had no impact on Hib antibody responses (GMR 0.91, 95% CI 0.68-1.22). The effect of CRM protein-polysaccharide conjugate vaccines on Hib antibody responses varies greatly between vaccines. Co-administration of a CRM conjugate vaccine can produce either positive or negative effects on Hib antibody responses. These inconsistencies suggest that CRM itself may not be the main driver of variability in Hib responses, and challenge current perspectives on this issue. Copyright © 2016 Elsevier Ltd. All rights reserved.
Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis.

PubMed

Buitrago-Lopez, Adriana; Sanderson, Jean; Johnson, Laura; Warnakula, Samantha; Wood, Angela; Di Angelantonio, Emanuele; Franco, Oscar H

2011-08-26

To evaluate the association of chocolate consumption with the risk of developing cardiometabolic disorders. Systematic review and meta-analysis of randomised controlled trials and observational studies. Medline, Embase, Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, reference lists of relevant studies to October 2010, and email contact with authors. Randomised trials and cohort, case-control, and cross sectional studies carried out in human adults, in which the association between chocolate consumption and the risk of outcomes related to cardiometabolic disorders were reported. Data were extracted by two independent investigators, and a consensus was reached with the involvement of a third. The primary outcome was cardiometabolic disorders, including cardiovascular disease (coronary heart disease and stroke), diabetes, and metabolic syndrome. A meta-analysis assessed the risk of developing cardiometabolic disorders by comparing the highest and lowest level of chocolate consumption. From 4576 references seven studies met the inclusion criteria (including 114,009 participants). None of the studies was a randomised trial, six were cohort studies, and one a cross sectional study. Large variation was observed between these seven studies for measurement of chocolate consumption, methods, and outcomes evaluated. Five of the seven studies reported a beneficial association between higher levels of chocolate consumption and the risk of cardiometabolic disorders. The highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease (relative risk 0.63 (95% confidence interval 0.44 to 0.90)) and a 29% reduction in stroke compared with the lowest levels. Based on observational evidence, levels of chocolate consumption seem to be associated with a substantial reduction in the risk of cardiometabolic disorders. Further experimental studies are required to confirm a potentially beneficial effect of chocolate consumption.
The effectiveness of simulation activities on the cognitive abilities of undergraduate third-year nursing students: a randomised control trial.

PubMed

Secomb, Jacinta; McKenna, Lisa; Smith, Colleen

2012-12-01

To provide evidence on the effectiveness of simulation activities on the clinical decision-making abilities of undergraduate nursing students. Based on previous research, it was hypothesised that the higher the cognitive score, the greater the ability a nursing student would have to make informed valid decisions in their clinical practice. Globally, simulation is being espoused as an education method that increases the competence of health professionals. At present, there is very little evidence to support current investment in time and resources. Following ethical approval, fifty-eight third-year undergraduate nursing students were randomised in a pretest-post-test group-parallel controlled trial. The learning environment preferences (LEP) inventory was used to test cognitive abilities in order to refute the null hypothesis that activities in computer-based simulated learning environments have a negative effect on cognitive abilities when compared with activities in skills laboratory simulated learning environments. There was no significant difference in cognitive development following two cycles of simulation activities. Therefore, it is reasonable to assume that two simulation tasks, either computer-based or laboratory-based, have no effect on an undergraduate student's ability to make clinical decisions in practice. However, there was a significant finding for non-English first-language students, which requires further investigation. More longitudinal studies that quantify the education effects of simulation on the cognitive, affective and psychomotor attributes of health science students and professionals from both English-speaking and non-English-speaking backgrounds are urgently required. It is also recommended that to achieve increased participant numbers and prevent non-participation owing to absenteeism, further studies need to be imbedded directly into curricula. This investigation confirms the effect of simulation activities on real-life clinical practice, and the comparative learning benefits with traditional clinical practice and university education remain unknown. © 2012 Blackwell Publishing Ltd.
The ring vaccination trial: a novel cluster randomised controlled trial design to evaluate vaccine efficacy and effectiveness during outbreaks, with special reference to Ebola.

PubMed

2015-07-27

A World Health Organization expert meeting on Ebola vaccines proposed urgent safety and efficacy studies in response to the outbreak in West Africa. One approach to communicable disease control is ring vaccination of individuals at high risk of infection due to their social or geographical connection to a known case. This paper describes the protocol for a novel cluster randomised controlled trial design which uses ring vaccination.In the Ebola ça suffit ring vaccination trial, rings are randomised 1:1 to (a) immediate vaccination of eligible adults with single dose vaccination or (b) vaccination delayed by 21 days. Vaccine efficacy against disease is assessed in participants over equivalent periods from the day of randomisation. Secondary objectives include vaccine effectiveness at the level of the ring, and incidence of serious adverse events. Ring vaccination trials are adaptive, can be run until disease elimination, allow interim analysis, and can go dormant during inter-epidemic periods. © Ebola ça suffit ring vaccination trial consortium 2015.
Gradual multifractal reconstruction of time-series: Formulation of the method and an application to the coupling between stock market indices and their Hölder exponents

NASA Astrophysics Data System (ADS)

Keylock, Christopher J.

2018-04-01

A technique termed gradual multifractal reconstruction (GMR) is formulated. A continuum is defined from a signal that preserves the pointwise Hölder exponent (multifractal) structure of a signal but randomises the locations of the original data values with respect to this (φ = 0), to the original signal itself(φ = 1). We demonstrate that this continuum may be populated with synthetic time series by undertaking selective randomisation of wavelet phases using a dual-tree complex wavelet transform. That is, the φ = 0 end of the continuum is realised using the recently proposed iterated, amplitude adjusted wavelet transform algorithm (Keylock, 2017) that fully randomises the wavelet phases. This is extended to the GMR formulation by selective phase randomisation depending on whether or not the wavelet coefficient amplitudes exceeds a threshold criterion. An econophysics application of the technique is presented. The relation between the normalised log-returns and their Hölder exponents for the daily returns of eight financial indices are compared. One particularly noticeable result is the change for the two American indices (NASDAQ 100 and S&P 500) from a non-significant to a strongly significant (as determined using GMR) cross-correlation between the returns and their Hölder exponents from before the 2008 crash to afterwards. This is also reflected in the skewness of the phase difference distributions, which exhibit a geographical structure, with Asian markets not exhibiting significant skewness in contrast to those from elsewhere globally.

Sample size calculations for cluster randomised crossover trials in Australian and New Zealand intensive care research.

PubMed

Arnup, Sarah J; McKenzie, Joanne E; Pilcher, David; Bellomo, Rinaldo; Forbes, Andrew B

2018-06-01

The cluster randomised crossover (CRXO) design provides an opportunity to conduct randomised controlled trials to evaluate low risk interventions in the intensive care setting. Our aim is to provide a tutorial on how to perform a sample size calculation for a CRXO trial, focusing on the meaning of the elements required for the calculations, with application to intensive care trials. We use all-cause in-hospital mortality from the Australian and New Zealand Intensive Care Society Adult Patient Database clinical registry to illustrate the sample size calculations. We show sample size calculations for a two-intervention, two 12-month period, cross-sectional CRXO trial. We provide the formulae, and examples of their use, to determine the number of intensive care units required to detect a risk ratio (RR) with a designated level of power between two interventions for trials in which the elements required for sample size calculations remain constant across all ICUs (unstratified design); and in which there are distinct groups (strata) of ICUs that differ importantly in the elements required for sample size calculations (stratified design). The CRXO design markedly reduces the sample size requirement compared with the parallel-group, cluster randomised design for the example cases. The stratified design further reduces the sample size requirement compared with the unstratified design. The CRXO design enables the evaluation of routinely used interventions that can bring about small, but important, improvements in patient care in the intensive care setting.
A Bayesian Hybrid Adaptive Randomisation Design for Clinical Trials with Survival Outcomes.

PubMed

Moatti, M; Chevret, S; Zohar, S; Rosenberger, W F

2016-01-01

Response-adaptive randomisation designs have been proposed to improve the efficiency of phase III randomised clinical trials and improve the outcomes of the clinical trial population. In the setting of failure time outcomes, Zhang and Rosenberger (2007) developed a response-adaptive randomisation approach that targets an optimal allocation, based on a fixed sample size. The aim of this research is to propose a response-adaptive randomisation procedure for survival trials with an interim monitoring plan, based on the following optimal criterion: for fixed variance of the estimated log hazard ratio, what allocation minimizes the expected hazard of failure? We demonstrate the utility of the design by redesigning a clinical trial on multiple myeloma. To handle continuous monitoring of data, we propose a Bayesian response-adaptive randomisation procedure, where the log hazard ratio is the effect measure of interest. Combining the prior with the normal likelihood, the mean posterior estimate of the log hazard ratio allows derivation of the optimal target allocation. We perform a simulation study to assess and compare the performance of this proposed Bayesian hybrid adaptive design to those of fixed, sequential or adaptive - either frequentist or fully Bayesian - designs. Non informative normal priors of the log hazard ratio were used, as well as mixture of enthusiastic and skeptical priors. Stopping rules based on the posterior distribution of the log hazard ratio were computed. The method is then illustrated by redesigning a phase III randomised clinical trial of chemotherapy in patients with multiple myeloma, with mixture of normal priors elicited from experts. As expected, there was a reduction in the proportion of observed deaths in the adaptive vs. non-adaptive designs; this reduction was maximized using a Bayes mixture prior, with no clear-cut improvement by using a fully Bayesian procedure. The use of stopping rules allows a slight decrease in the observed proportion of deaths under the alternate hypothesis compared with the adaptive designs with no stopping rules. Such Bayesian hybrid adaptive survival trials may be promising alternatives to traditional designs, reducing the duration of survival trials, as well as optimizing the ethical concerns for patients enrolled in the trial.
Development of a cross-section based stream package for MODFLOW

NASA Astrophysics Data System (ADS)

Ou, G.; Chen, X.; Irmak, A.

2012-12-01

Accurate simulation of stream-aquifer interactions for wide rivers using the streamflow routing package in MODFLOW is very challenging. To better represent a wide river spanning over multiple model grid cells, a Cross-Section based streamflow Routing (CSR) package is developed and incorporated into MODFLOW to simulate the interaction between streams and aquifers. In the CSR package, a stream segment is represented as a four-point polygon instead of a polyline which is traditionally used in streamflow routing simulation. Each stream segment is composed of upstream and downstream cross-sections. A cross-section consists of a number of streambed points possessing coordinates, streambed thicknesses and streambed hydraulic conductivities to describe the streambed geometry and hydraulic properties. The left and right end points are used to determine the locations of the stream segments. According to the cross-section geometry and hydraulic properties, CSR calculates the new stream stage at the cross-section using the Brent's method to solve the Manning's Equation. A module is developed to automatically compute the area of the stream segment polygon on each intersected MODFLOW grid cell as the upstream and downstream stages change. The stream stage and streambed hydraulic properties of model grids are interpolated based on the streambed points. Streambed leakage is computed as a function of streambed conductance and difference between the groundwater level and stream stage. The Muskingum-Cunge flow routing scheme with variable parameters is used to simulate the streamflow as the groundwater (discharge or recharge) contributes as lateral flows. An example is used to illustrate the capabilities of the CSR package. The result shows that the CSR is applicable to describing the spatial and temporal variation in the interaction between streams and aquifers. The input data become simple due to that the internal program automatically interpolates the cross-section data to each model grid cell.
Laparoscopic simulation training in gynaecology: Current provision and staff attitudes - a cross-sectional survey.

PubMed

Burden, Christy; Fox, Robert; Hinshaw, Kim; Draycott, Timothy J; James, Mark

2016-01-01

The objectives of this study were to explore current provision of laparoscopic simulation training, and to determine attitudes of trainers and trainees to the role of simulators in surgical training across the UK. An anonymous cross-sectional survey with cluster sampling was developed and circulated. All Royal College of Obstetricians and Gynaecologists (RCOG) Training Programme Directors (TPD), College Tutors (RCT) and Trainee representatives (TR) across the UK were invited to participate. One hundred and ninety-six obstetricians and gynaecologists participated. Sixty-three percent of hospitals had at least one box trainer, and 14.6% had least one virtual-reality simulator. Only 9.3% and 3.6% stated that trainees used a structured curriculum on box and virtual-reality simulators, respectively. Respondents working in a Large/Teaching hospital (p = 0.008) were more likely to agree that simulators enhance surgical training. Eighty-nine percent agreed that simulators improve the quality of training, and should be mandatory or desirable for junior trainees. Consultants (p = 0.003) and respondents over 40 years (p = 0.011) were more likely to hold that a simulation test should be undertaken before live operation. Our data demonstrated, therefore, that availability of laparoscopic simulators is inconsistent, with limited use of mandatory structured curricula. In contrast, both trainers and trainees recognise a need for greater use of laparoscopic simulation for surgical training.
Determination of Vertical Borehole and Geological Formation Properties using the Crossed Contour Method

PubMed Central

Leyde, Brian P.; Klein, Sanford A; Nellis, Gregory F.; Skye, Harrison

2017-01-01

This paper presents a new method called the Crossed Contour Method for determining the effective properties (borehole radius and ground thermal conductivity) of a vertical ground-coupled heat exchanger. The borehole radius is used as a proxy for the overall borehole thermal resistance. The method has been applied to both simulated and experimental borehole Thermal Response Test (TRT) data using the Duct Storage vertical ground heat exchanger model implemented in the TRansient SYstems Simulation software (TRNSYS). The Crossed Contour Method generates a parametric grid of simulated TRT data for different combinations of borehole radius and ground thermal conductivity in a series of time windows. The error between the average of the simulated and experimental bore field inlet and outlet temperatures is calculated for each set of borehole properties within each time window. Using these data, contours of the minimum error are constructed in the parameter space of borehole radius and ground thermal conductivity. When all of the minimum error contours for each time window are superimposed, the point where the contours cross (intersect) identifies the effective borehole properties for the model that most closely represents the experimental data in every time window and thus over the entire length of the experimental data set. The computed borehole properties are compared with results from existing model inversion methods including the Ground Property Measurement (GPM) software developed by Oak Ridge National Laboratory, and the Line Source Model. PMID:28785125
The “Resus:Station”: The use of clinical simulations in a randomised crossover study to evaluate a novel resuscitation trolley☆

PubMed Central

Walker, Susanna T.; Brett, Stephen J.; McKay, Anthony; Aggarwal, Rajesh; Vincent, Charles

2012-01-01

Background and aim Inadequately designed equipment has been implicated in poor efficiency and critical incidents associated with resuscitation. A novel resuscitation trolley (Resus:Station) was designed and evaluated for impact on team efficiency, user opinion, and teamwork, compared with the standard trolley, in simulated cardiac arrest scenarios. Methods Fifteen experienced cardiac arrest teams were recruited (45 participants). Teams performed recorded resuscitation simulations using new and conventional trolleys, with order of use randomised. After each simulation, efficiency (“time to drugs”, un-locatable equipment, unnecessary drawer opening) and team performance (OSCAR) were assessed from the video recordings and participants were asked to complete questionnaires scoring various aspects of the trolley on a Likert scale. Results Time to locate the drugs was significantly faster (p = 0.001) when using the Resus:Station (mean 5.19 s (SD 3.34)) than when using the standard trolley (26.81 s (SD16.05)). There were no reports of missing equipment when using the Resus:Station. However, during four of the fifteen study sessions using the standard trolley participants were unable to find equipment, with an average of 6.75 unnecessary drawer openings per simulation. User feedback results clearly indicated a highly significant preference for the newly designed Resus:Station for all aspects. Teams performed equally well for all dimensions of team performance using both trolleys, despite it being their first exposure to the Resus:Station. Conclusion We conclude that in this simulated environment, the new design of trolley is safe to use, and has the potential to improve efficiency at a resuscitation attempt. PMID:22796405
An embedded checklist in the Anesthesia Information Management System improves pre-anaesthetic induction setup: a randomised controlled trial in a simulation setting.

PubMed

Wetmore, Douglas; Goldberg, Andrew; Gandhi, Nishant; Spivack, John; McCormick, Patrick; DeMaria, Samuel

2016-10-01

Anaesthesiologists work in a high stress, high consequence environment in which missed steps in preparation may lead to medical errors and potential patient harm. The pre-anaesthetic induction period has been identified as a time in which medical errors can occur. The Anesthesia Patient Safety Foundation has developed a Pre-Anesthetic Induction Patient Safety (PIPS) checklist. We conducted this study to test the effectiveness of this checklist, when embedded in our institutional Anesthesia Information Management System (AIMS), on resident performance in a simulated environment. Using a randomised, controlled, observer-blinded design, we compared performance of anaesthesiology residents in a simulated operating room under production pressure using a checklist in completing a thorough pre-anaesthetic induction evaluation and setup with that of residents with no checklist. The checklist was embedded in the simulated operating room's electronic medical record. Data for 38 anaesthesiology residents shows a statistically significant difference in performance in pre-anaesthetic setup and evaluation as scored by blinded raters (maximum score 22 points), with the checklist group performing better by 7.8 points (p<0.01). The effects of gender and year of residency on total score were not significant. Simulation duration (time to anaesthetic agent administration) was increased significantly by the use of the checklist. Required use of a pre-induction checklist improves anaesthesiology resident performance in a simulated environment. The PIPS checklist as an integrated part of a departmental AIMS warrant further investigation as a quality measure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Effect of virtual reality training on laparoscopic surgery: randomised controlled trial

PubMed Central

Soerensen, Jette L; Grantcharov, Teodor P; Dalsgaard, Torur; Schouenborg, Lars; Ottosen, Christian; Schroeder, Torben V; Ottesen, Bent S

2009-01-01

Objective To assess the effect of virtual reality training on an actual laparoscopic operation. Design Prospective randomised controlled and blinded trial. Setting Seven gynaecological departments in the Zeeland region of Denmark. Participants 24 first and second year registrars specialising in gynaecology and obstetrics. Interventions Proficiency based virtual reality simulator training in laparoscopic salpingectomy and standard clinical education (controls). Main outcome measure The main outcome measure was technical performance assessed by two independent observers blinded to trainee and training status using a previously validated general and task specific rating scale. The secondary outcome measure was operation time in minutes. Results The simulator trained group (n=11) reached a median total score of 33 points (interquartile range 32-36 points), equivalent to the experience gained after 20-50 laparoscopic procedures, whereas the control group (n=10) reached a median total score of 23 (22-27) points, equivalent to the experience gained from fewer than five procedures (P<0.001). The median total operation time in the simulator trained group was 12 minutes (interquartile range 10-14 minutes) and in the control group was 24 (20-29) minutes (P<0.001). The observers’ inter-rater agreement was 0.79. Conclusion Skills in laparoscopic surgery can be increased in a clinically relevant manner using proficiency based virtual reality simulator training. The performance level of novices was increased to that of intermediately experienced laparoscopists and operation time was halved. Simulator training should be considered before trainees carry out laparoscopic procedures. Trial registration ClinicalTrials.gov NCT00311792. PMID:19443914
Re-estimating sample size in cluster randomised trials with active recruitment within clusters.

PubMed

van Schie, S; Moerbeek, M

2014-08-30

Often only a limited number of clusters can be obtained in cluster randomised trials, although many potential participants can be recruited within each cluster. Thus, active recruitment is feasible within the clusters. To obtain an efficient sample size in a cluster randomised trial, the cluster level and individual level variance should be known before the study starts, but this is often not the case. We suggest using an internal pilot study design to address this problem of unknown variances. A pilot can be useful to re-estimate the variances and re-calculate the sample size during the trial. Using simulated data, it is shown that an initially low or high power can be adjusted using an internal pilot with the type I error rate remaining within an acceptable range. The intracluster correlation coefficient can be re-estimated with more precision, which has a positive effect on the sample size. We conclude that an internal pilot study design may be used if active recruitment is feasible within a limited number of clusters. Copyright © 2014 John Wiley & Sons, Ltd.
Patient-oriented randomisation: A new trial design applied in the Neuroleptic Strategy Study.

PubMed

Schulz, Constanze; Timm, Jürgen; Cordes, Joachim; Gründer, Gerhard; Mühlbauer, Bernd; Rüther, Eckart; Heinze, Martin

2016-06-01

The 'gold standard' for clinical studies is a randomised controlled trial usually comparing specific treatments. If the scientific study expands to strategy comparison with each strategy including various treatments, the research problems are increasingly complicated. The strategy debate in the psychiatric community is the starting point for the development of our new design. It is widely accepted that second-generation antipsychotics are the therapy of choice in the treatment of schizophrenia. However, their general superiority over first-generation antipsychotics could not be demonstrated in recent randomised controlled trials. Furthermore, we are becoming increasingly aware that the experimental conditions of randomised controlled trials, as in the European First Episode Schizophrenia Trial and Clinical Antipsychotic Trials of Intervention Effectiveness Phase 1 studies, may be inappropriate for psychiatric treatments. The high heterogeneity in the patient population produces discrepancies between daily clinical perception and randomised controlled trials results. The patient-oriented approach in the Cost Utility of the Latest Antipsychotic drugs in Schizophrenia Study reflects everyday clinical practice. The results, however, are highly dependent on the physicians' preferences. The goal of the design described here is to take an intermediate path between randomised controlled trials and clinical studies such as Cost Utility of the Latest Antipsychotic Drugs in Schizophrenia Study, combining the advantages of both study types. The idea is to randomise two treatment pairs each consisting of one first-generation antipsychotic and one second-generation antipsychotic in a first step and subsequently, to involve the investigators in deciding for a pair most appropriate to the patients' needs and then to randomise the allocation to one drug (first-generation antipsychotic or second-generation antipsychotic) of that chosen pair. This idea was first implemented in the clinical trial, the Neuroleptic Strategy Study, with a randomised design comparing efficacy and safety of two different strategies: either to use first-generation antipsychotics (haloperidol and flupentixol) or second-generation antipsychotics (olanzapine, aripiprazole and quetiapine) in patients suffering from schizophrenia. In the course of the Neuroleptic Strategy Study, feasibility of this design was demonstrated. All aspects of the new design were implemented: randomisation process, documentation of responses from investigators as well as patients and drug logistic experience. In implementing the design, furthermore, we could investigate its theoretical properties. The physicians' preferences for specific drugs used for the respective patients were analysed. The idea of patient-oriented randomisation can be generalised. In light of the heterogeneity and complexity of patient-drug interaction, this design should prove particularly useful. © The Author(s) 2016.
Stability of ARDS subphenotypes over time in two randomised controlled trials.

PubMed

Delucchi, Kevin; Famous, Katie R; Ware, Lorraine B; Parsons, Polly E; Thompson, B Taylor; Calfee, Carolyn S

2018-05-01

Two distinct acute respiratory distress syndrome (ARDS) subphenotypes have been identified using data obtained at time of enrolment in clinical trials; it remains unknown if these subphenotypes are durable over time. To determine the stability of ARDS subphenotypes over time. Secondary analysis of data from two randomised controlled trials in ARDS, the ARMA trial of lung protective ventilation (n=473; patients randomised to low tidal volumes only) and the ALVEOLI trial of low versus high positive end-expiratory pressure (n=549). Latent class analysis (LCA) and latent transition analysis (LTA) were applied to data from day 0 and day 3, independent of clinical outcomes. In ALVEOLI, LCA indicated strong evidence of two ARDS latent classes at days 0 and 3; in ARMA, evidence of two classes was stronger at day 0 than at day 3. The clinical and biological features of these two classes were similar to those in our prior work and were largely stable over time, though class 2 demonstrated evidence of progressive organ failures by day 3, compared with class 1. In both LCA and LTA models, the majority of patients (>94%) stayed in the same class from day 0 to day 3. Clinical outcomes were statistically significantly worse in class 2 than class 1 and were more strongly associated with day 3 class assignment. ARDS subphenotypes are largely stable over the first 3 days of enrolment in two ARDS Network trials, suggesting that subphenotype identification may be feasible in the context of clinical trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Comparison of forcing functions in magnetohydrodynamics

NASA Astrophysics Data System (ADS)

McKay, Mairi E.; Linkmann, Moritz; Clark, Daniel; Chalupa, Adam A.; Berera, Arjun

2017-11-01

Results are presented of direct numerical simulations of incompressible, homogeneous magnetohydrodynamic turbulence without a mean magnetic field, subject to different mechanical forcing functions commonly used in the literature. Specifically, the forces are negative damping (which uses the large-scale velocity field as a forcing function), a nonhelical random force, and a nonhelical static sinusoidal force (analogous to helical ABC forcing). The time evolution of the three ideal invariants (energy, magnetic helicity, and cross helicity), the time-averaged energy spectra, the energy ratios, and the dissipation ratios are examined. All three forcing functions produce qualitatively similar steady states with regard to the time evolution of the energy and magnetic helicity. However, differences in the cross-helicity evolution are observed, particularly in the case of the static sinusoidal method of energy injection. Indeed, an ensemble of sinusoidally forced simulations with identical parameters shows significant variations in the cross helicity over long time periods, casting some doubt on the validity of the principle of ergodicity in systems in which the injection of helicity cannot be controlled. Cross helicity can unexpectedly enter the system through the forcing function and must be carefully monitored.
Evaluating a Cross-Continent EU Simulation

ERIC Educational Resources Information Center

Jones, Rebecca

2008-01-01

Assessment of learning outcomes and evaluation of teaching methods are necessary in order to ensure that students are learning the lessons that faculty believe they are conveying. Quantitative data on the effectiveness of various pedagogical methods allows faculty to make adjustments to classes over time. Regular assessment of student learning…
A systematic review of training programmes for recruiters to randomised controlled trials.

PubMed

Townsend, Daisy; Mills, Nicola; Savović, Jelena; Donovan, Jenny L

2015-09-28

Recruitment to randomised controlled trials (RCTs) is often difficult. Clinician related factors have been implicated as important reasons for low rates of recruitment. Clinicians (doctors and other health professionals) can experience discomfort with some underlying principles of RCTs and experience difficulties in conveying them positively to potential trial participants. Recruiter training has been suggested to address identified problems but a synthesis of this research is lacking. The aim of our study was to systematically review the available evidence on training interventions for recruiters to randomised trials. Studies that evaluated training programmes for trial recruiters were included. Those that provided only general communication training not linked to RCT recruitment were excluded. Data extraction and quality assessment were completed by two reviewers independently, with a third author where necessary. Seventeen studies of 9615 potentially eligible titles and abstracts were included in the review: three randomised controlled studies, two non-randomised controlled studies, nine uncontrolled pre-test/post-test studies, two qualitative studies, and a post-training questionnaire survey. Most studies were of moderate or weak quality. Training programmes were mostly set within cancer trials, and usually consisted of workshops with a mix of health professionals over one or two consecutive days covering generic and trial specific issues. Recruiter training programmes were well received and some increased recruiters' self-confidence in communicating key RCT concepts to patients. There was, however, little evidence that this training increased actual recruitment rates or patient understanding, satisfaction, or levels of informed consent. There is a need to develop recruiter training programmes that can lead to improved recruitment and informed consent in randomised trials.
Foot orthoses in the treatment of symptomatic midfoot osteoarthritis using clinical and biomechanical outcomes: a randomised feasibility study.

PubMed

Halstead, Jill; Chapman, Graham J; Gray, Janine C; Grainger, Andrew J; Brown, Sarah; Wilkins, Richard A; Roddy, Edward; Helliwell, Philip S; Keenan, Anne-Maree; Redmond, Anthony C

2016-04-01

This randomised feasibility study aimed to examine the clinical and biomechanical effects of functional foot orthoses (FFOs) in the treatment of midfoot osteoarthritis (OA) and the feasibility of conducting a full randomised controlled trial. Participants with painful, radiographically confirmed midfoot OA were recruited and randomised to receive either FFOs or a sham control orthosis. Feasibility measures included recruitment and attrition rates, practicality of blinding and adherence rates. Clinical outcome measures were: change from baseline to 12 weeks for severity of pain (numerical rating scale), foot function (Manchester Foot Pain and Disability Index) and patient global impression of change scale. To investigate the biomechanical effect of foot orthoses, in-shoe foot kinematics and plantar pressures were evaluated at 12 weeks. Of the 119 participants screened, 37 were randomised and 33 completed the study (FFO = 18, sham = 15). Compliance with foot orthoses and blinding of the intervention was achieved in three quarters of the group. Both groups reported improvements in pain, function and global impression of change; the FFO group reporting greater improvements compared to the sham group. The biomechanical outcomes indicated the FFO group inverted the hindfoot and increased midfoot maximum plantar force compared to the sham group. The present findings suggest FFOs worn over 12 weeks may provide detectable clinical and biomechanical benefits compared to sham orthoses. This feasibility study provides useful clinical, biomechanical and statistical information for the design and implementation of a definitive randomised controlled trial to evaluate the effectiveness of FFOs in treating painful midfoot OA.
Time matters--realism in resuscitation training.

PubMed

Krogh, Kristian B; Høyer, Christian B; Ostergaard, Doris; Eika, Berit

2014-08-01

The advanced life support guidelines recommend 2min of cardiopulmonary resuscitation (CPR) and minimal hands-off time to ensure sufficient cardiac and cerebral perfusion. We have observed doctors who shorten the CPR intervals during resuscitation attempts. During simulation-based resuscitation training, the recommended 2-min CPR cycles are often deliberately decreased in order to increase the number of scenarios. The aim of this study was to test if keeping 2-min CPR cycles during resuscitation training ensures better adherence to time during resuscitation in a simulated setting. This study was designed as a randomised control trial. Fifty-four 4th-year medical students with no prior advanced resuscitation training participated in an extra-curricular one-day advanced life support course. Participants were either randomised to simulation-based training using real-time (120s) or shortened CPR cycles (30-45s instead of 120s) in the scenarios. Adherence to time was measured using the European Resuscitation Council's Cardiac Arrest Simulation Test (CASTest) in retention tests conducted one and 12 weeks after the course. The real-time group adhered significantly better to the recommended 2-min CPR cycles (time-120s) (mean 13; standard derivation (SD) 8) than the shortened CPR cycle group (mean 45; SD 19) when tested (p<0.001.) This study indicates that time is an important part of fidelity. Variables critical for performance, like adherence to time in resuscitation, should therefore be kept realistic during training to optimise outcome. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population [ISRCTN89345269

PubMed Central

Mant, Jonathan WF; Richards, Suzanne H; Hobbs, FD Richard; Fitzmaurice, David; Lip, Gregory YH; Murray, Ellen; Banting, Miriam; Fletcher, Kate; Rahman, Joy; Allan, Teresa; Raftery, James; Bryan, Stirling

2003-01-01

Background Atrial fibrillation (AF) is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly. The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting. Study design A randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire. 1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa). The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic) or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular), hospital admissions (all cause, vascular), cognition, quality of life, disability and compliance with study medication. PMID:12939169
Home-based Reach-to-Grasp training for people after stroke is feasible: a pilot randomised controlled trial.

PubMed

Turton, A J; Cunningham, P; van Wijck, F; Smartt, Hjm; Rogers, C A; Sackley, C M; Jowett, S; Wolf, S L; Wheatley, K; van Vliet, P

2017-07-01

To determine feasibility of a randomised controlled trial (RCT) of home-based Reach-to-Grasp training after stroke. single-blind parallel group RCT. Residual arm deficit less than 12 months post-stroke. Reach-to-Grasp training in 14 one-hour therapist's visits over 6 weeks, plus one hour self-practice per day (total 56 hours). Usual care. Action Research Arm Test (ARAT), Wolf Motor Function Test (WMFT), pre-randomisation, 7, 12, 24 weeks post-randomisation. Forty-seven participants (Reach-to-Grasp=24, usual care=23) were randomised over 17 months. Reach-to-Grasp participants received a median (IQR) 14 (13,14) visits, and performed 157 (96,211) repetitions per visit; plus 30 minutes (22,45) self-practice per day. Usual care participants received 10.5 (5,14) therapist visits, comprising 38.6 (30,45) minutes of arm therapy with 16 (6,24) repetitions of functional tasks per visit. Median ARAT scores in the reach-to-grasp group were 8.5 (3.0,24.0) at baseline and 14.5 (3.5,26.0) at 24 weeks compared to median of 4 at both time points (IQR: baseline (3.0,14.0), 24 weeks (3.0,30.0)) in the usual-care group. Median WMFT tasks completed at baseline and 24 weeks were 6 (3.0,11.5) and 8.5 (4.5,13.5) respectively in the reach-to-grasp group and 4 (3.0,10.0), 6 (3.0,14.0) in the usual care group. Incidence of arm pain was similar between groups. The study was stopped before 11 patients reached the 24 weeks assessment. An RCT of home-based Reach-to-Grasp training after stroke is feasible and safe. With ARAT being our preferred measure it is estimated that 240 participants will be needed for a future two armed trial.
Rapid diagnostic tests compared with malaria microscopy for guiding outpatient treatment of febrile illness in Tanzania: randomised trial.

PubMed

Reyburn, Hugh; Mbakilwa, Hilda; Mwangi, Rose; Mwerinde, Ombeni; Olomi, Raimos; Drakeley, Chris; Whitty, Christopher J M

2007-02-24

To compare rapid diagnostic tests (RDTs) for malaria with routine microscopy in guiding treatment decisions for febrile patients. Randomised trial. Outpatient departments in northeast Tanzania at varying levels of malaria transmission. 2416 patients for whom a malaria test was requested. Staff received training on rapid diagnostic tests; patients sent for malaria tests were randomised to rapid diagnostic test or routine microscopy Proportion of patients with a negative test prescribed an antimalarial drug. Of 7589 outpatient consultations, 2425 (32%) had a malaria test requested. Of 1204 patients randomised to microscopy, 1030 (86%) tested negative for malaria; 523 (51%) of these were treated with an antimalarial drug. Of 1193 patients randomised to rapid diagnostic test, 1005 (84%) tested negative; 540 (54%) of these were treated for malaria (odds ratio 1.13, 95% confidence interval 0.95 to 1.34; P=0.18). Children aged under 5 with negative rapid diagnostic tests were more likely to be prescribed an antimalarial drug than were those with negative slides (P=0.003). Patients with a negative test by any method were more likely to be prescribed an antibiotic (odds ratio 6.42, 4.72 to 8.75; P<0.001). More than 90% of prescriptions for antimalarial drugs in low-moderate transmission settings were for patients for whom a test requested by a clinician was negative for malaria. Although many cases of malaria are missed outside the formal sector, within it malaria is massively over-diagnosed. This threatens the sustainability of deployment of artemisinin combination treatment, and treatable bacterial diseases are likely to be missed. Use of rapid diagnostic tests, with basic training for clinical staff, did not in itself lead to any reduction in over-treatment for malaria. Interventions to improve clinicians' management of febrile illness are essential but will not be easy. Clinical trials NCT00146796 [ClinicalTrials.gov].
Modafinil combined with cognitive training is associated with improved learning in healthy volunteers--a randomised controlled trial.

PubMed

Gilleen, J; Michalopoulou, P G; Reichenberg, A; Drake, R; Wykes, T; Lewis, S W; Kapur, S

2014-04-01

Improving cognition in people with neuropsychiatric disorders remains a major clinical target. By themselves pharmacological and non-pharmacological approaches have shown only modest effects in improving cognition. In the present study we tested a recently-proposed methodology to combine CT with a 'cognitive-enhancing' drug to improve cognitive test scores and expanded on previous approaches by delivering combination drug and CT, over a long intervention of repeated sessions, and used multiple tasks to reveal the cognitive processes being enhanced. We also aimed to determine whether gains from this combination approach generalised to untrained tests. In this proof of principle randomised-controlled trial thirty-three healthy volunteers were randomised to receive either modafinil or placebo combined with daily cognitive training over two weeks. Volunteers were trained on tasks of new-language learning, working memory and verbal learning following 200 mg modafinil or placebo for ten days. Improvements in trained and untrained tasks were measured. Rate of new-language learning was significantly enhanced with modafinil, and effects were greatest over the first five sessions. Modafinil improved within-day learning rather than between-day retention. No enhancement of gains with modafinil was observed in working memory nor rate of verbal learning. Gains in all tasks were retained post drug-administration, but transfer effects to broad cognitive abilities were not seen. This study shows that combining CT with modafinil specifically elevates learning over early training sessions compared to CT with placebo and provides a proof of principle experimental paradigm for pharmacological enhancement of cognitive remediation. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

Cost-Effectiveness of Capping Freeways for Use as Parks: The New York Cross-Bronx Expressway Case Study

PubMed Central

Zafari, Zafar; Bellanger, Martine; Muennig, Peter Alexander

2018-01-01

Objectives. To examine health benefits and cost-effectiveness of implementing a freeway deck park to increase urban green space. Methods. Using the Cross-Bronx Expressway in New York City as a case study, we explored the cost-effectiveness of implementing deck parks. We built a microsimulation model that included increased exercise, fewer accidents, and less pollution as well as the cost of implementation and maintenance of the park. We estimated both the quality-adjusted life years gained and the societal costs for 2017. Results. Implementation of a deck park over sunken parts of Cross-Bronx Expressway appeared to save both lives and money. Savings were realized for 84% of Monte Carlo simulations. Conclusions. In a rapidly urbanizing world, reclaiming green space through deck parks can bring health benefits alongside economic savings over the long term. Public Health Implications. Policymakers are seeking ways to create cross-sectorial synergies that might improve both quality of urban life and health. However, such projects are very expensive, and there is little information on their return of investment. Our analysis showed that deck parks produce exceptional value when implemented over below-grade sections of road. PMID:29345999
Impact of cooked functional meat enriched with omega-3 fatty acids and rosemary extract on inflammatory and oxidative status; a randomised, double-blind, crossover study.

PubMed

Bermejo, L M; López-Plaza, B; Weber, T K; Palma-Milla, S; Iglesias, C; Reglero, G; Gómez-Candela, C

2014-11-01

n-3 fatty acid intake has been associated with inflammatory benefits in cardiovascular disease (CVD). Functionalising meat may be of great interest. The aim of the present study was to assess the effect of functional meat containing n-3 and rosemary extract on inflammatory and oxidative status markers in subjects with risk for CVD. A randomised, double-blind, cross-over study was undertaken to compare the effects on the above markers of consuming functional or control meat products. 43 volunteers with at least two lipid profile variables showing risk for CVD were randomly assigned to receive functional meat (FM) or control meat (CM) over 12-weeks with a 4-week wash-out interval before crossover. Functional effects were assessed by examining lipid profile, CRP, PAI-1, TNF-alpha, IL-6, fibrinogen (inflammatory markers), and TBARS, FRAP and 8-iso-PGF2 (oxidative status markers). 33 subjects (24 women) aged 50.7±8.8 years completed the study. In FM treatment, PAI-1, fibrinogen and 8-iso-PGF2 decreased significantly after 12 weeks, while FRAP significantly increased. In contrast, in CM treatment, a significant increase was seen in PAI-1, while FRAP significantly declined. Significant differences were also seen between the FM and CM treatments after 12 weeks in terms of the change observed in PAI-1, FRAP and 8-iso-PGF2 values. No significant differences were seen in anthropometric variables nor were adverse effects reported. The consumption of FM containing n-3 and rosemary extract improved oxidative and inflammatory status of people with at least two lipid profile variables showing risk for CVD. The inclusion of such functional meat in a balanced diet might be a healthy lifestyle option. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Adaptation of running pattern to the drop of standard cushioned shoes: A randomised controlled trial with a 6-month follow-up.

PubMed

Malisoux, Laurent; Gette, Paul; Chambon, Nicolas; Urhausen, Axel; Theisen, Daniel

2017-08-01

While several cross-sectional studies have investigated the acute effects of shoe drop on running biomechanics, the long-term consequences are currently unknown. This study aimed to investigate if the drop of standard cushioned shoes induces specific adaptations in running technique over a six-month period in leisure-time runners. Double-blinded randomised controlled trial. The participants (n=59) received a pair of shoes with a heel-to-toe drop of 10mm (D10), 6mm (D6) or 0mm (D0) and were followed-up regarding running training over 6 months or 500km, whichever came first. Spatio-temporal variables and kinematics (foot/ground, ankle and knee joint angles) were investigated while running at preferred speed on a treadmill before and after the follow-up. The participants ran 332±178km in the study shoes between pre- and post-tests. There was no shoe version by time interaction for any of the spatio-temporal variables nor for lower limb angles at initial ground contact. A small but significant shoe drop effect was found for knee abduction at mid-stance (p=0.032), as it decreased for the D0 version (-0.3±3.1 vs. -1.3±2.6°) while it increased for the D6 (0.3±2.7 vs. 1.3±3.1°) and D10 version (-0.2±3.2 vs. 0.5±3.1°). However, none of the pairwise comparisons was significant in the post-hoc analysis. Apart from knee abduction at mid-stance, no specific adaptation in spatio-temporal variables and kinematics was found between the three shoe versions during this 6-month follow-up. Thus, shoe drop of standard cushioned shoes does not seem to influence running biomechanics in the long term. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Adjusting for treatment switching in randomised controlled trials - A simulation study and a simplified two-stage method.

PubMed

Latimer, Nicholas R; Abrams, K R; Lambert, P C; Crowther, M J; Wailoo, A J; Morden, J P; Akehurst, R L; Campbell, M J

2017-04-01

Estimates of the overall survival benefit of new cancer treatments are often confounded by treatment switching in randomised controlled trials (RCTs) - whereby patients randomised to the control group are permitted to switch onto the experimental treatment upon disease progression. In health technology assessment, estimates of the unconfounded overall survival benefit associated with the new treatment are needed. Several switching adjustment methods have been advocated in the literature, some of which have been used in health technology assessment. However, it is unclear which methods are likely to produce least bias in realistic RCT-based scenarios. We simulated RCTs in which switching, associated with patient prognosis, was permitted. Treatment effect size and time dependency, switching proportions and disease severity were varied across scenarios. We assessed the performance of alternative adjustment methods based upon bias, coverage and mean squared error, related to the estimation of true restricted mean survival in the absence of switching in the control group. We found that when the treatment effect was not time-dependent, rank preserving structural failure time models (RPSFTM) and iterative parameter estimation methods produced low levels of bias. However, in the presence of a time-dependent treatment effect, these methods produced higher levels of bias, similar to those produced by an inverse probability of censoring weights method. The inverse probability of censoring weights and structural nested models produced high levels of bias when switching proportions exceeded 85%. A simplified two-stage Weibull method produced low bias across all scenarios and provided the treatment switching mechanism is suitable, represents an appropriate adjustment method.
WITHDRAWN: Systemic treatments for metastatic cutaneous melanoma.

PubMed

Crosby, Tom; Fish, Reg; Coles, Bernadette; Mason, Malcolm

2018-02-07

Systemic therapies for metastatic cutaneous melanoma, the most aggressive of all skin cancers, remain disappointing. Few lasting remissions are achieved and the therapeutic aim remains one of palliation.Many agents are used alone or in combination with varying degrees of toxicity and cost. It is unclear whether evidence exists to support these complex regimens over best supportive care / placebo. To review the benefits from the use of systemic therapies in metastatic cutaneous melanoma compared to best supportive care/placebo, and to establish whether a 'standard' therapy exists which is superior to other treatments. Randomised controlled trials were identified from the MEDLINE, EMBASE and CCTR/CENTRAL databases. References, conference proceedings, and Science Citation Index/Scisearch were also used to locate trials. Cancer registries and trialists were also contacted. Randomised controlled trials of adults with histologically proven metastatic cutaneous melanoma in which systemic anti-cancer therapy was compared with placebo or supportive care. Study selection was performed by two independent reviewers. Data extraction forms were used for studies which appeared to meet the selection criteria and, where appropriate, full text articles were retrieved and reviewed independently. No randomised controlled trials were found comparing a systemic therapy with placebo or best supportive care in metastatic cutaneous melanoma. There is no evidence from randomised controlled clinical trials to show superiority of systemic therapy over best supportive care / placebo in the treatment of malignant cutaneous melanoma.Given that patients with metastatic melanoma frequently receive systemic therapy, it is our pragmatic view that a future systematic review could compare any systemic treatment, or combination of treatments, to single agent dacarbazine.
A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial

PubMed Central

Standen, PJ; Threapleton, K; Richardson, A; Connell, L; Brown, DJ; Battersby, S; Platts, F; Burton, A

2016-01-01

Objective: To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke. Design: Two group feasibility randomised controlled trial of intervention versus usual care. Setting: Patients’ homes. Participants: Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation. Interventions: Eight weeks’ use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care. Main measures: The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living. Results: Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient. Conclusions: To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support. PMID:27029939
A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial.

PubMed

Standen, P J; Threapleton, K; Richardson, A; Connell, L; Brown, D J; Battersby, S; Platts, F; Burton, A

2017-03-01

To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke. Two group feasibility randomised controlled trial of intervention versus usual care. Patients' homes. Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation. Eight weeks' use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care. The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living. Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient. To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support.
A randomised controlled trial of three or one breathing technique training sessions for breathlessness in people with malignant lung disease.

PubMed

Johnson, Miriam J; Kanaan, Mona; Richardson, Gerry; Nabb, Samantha; Torgerson, David; English, Anne; Barton, Rachael; Booth, Sara

2015-09-07

About 90 % of patients with intra-thoracic malignancy experience breathlessness. Breathing training is helpful, but it is unknown whether repeated sessions are needed. The present study aims to test whether three sessions are better than one for breathlessness in this population. This is a multi-centre randomised controlled non-blinded parallel arm trial. Participants were allocated to three sessions or single (1:2 ratio) using central computer-generated block randomisation by an independent Trials Unit and stratified for centre. The setting was respiratory, oncology or palliative care clinics at eight UK centres. Inclusion criteria were people with intrathoracic cancer and refractory breathlessness, expected prognosis ≥3 months, and no prior experience of breathing training. The trial intervention was a complex breathlessness intervention (breathing training, anxiety management, relaxation, pacing, and prioritisation) delivered over three hour-long sessions at weekly intervals, or during a single hour-long session. The main primary outcome was worst breathlessness over the previous 24 hours ('worst'), by numerical rating scale (0 = none; 10 = worst imaginable). Our primary analysis was area under the curve (AUC) 'worst' from baseline to 4 weeks. All analyses were by intention to treat. Between April 2011 and October 2013, 156 consenting participants were randomised (52 three; 104 single). Overall, the 'worst' score reduced from 6.81 (SD, 1.89) to 5.84 (2.39). Primary analysis [n = 124 (79 %)], showed no between-arm difference in the AUC: three sessions 22.86 (7.12) vs single session 22.58 (7.10); P value = 0.83); mean difference 0.2, 95 % CIs (-2.31 to 2.97). Complete case analysis showed a non-significant reduction in QALYs with three sessions (mean difference -0.006, 95 % CIs -0.018 to 0.006). Sensitivity analyses found similar results. The probability of the single session being cost-effective (threshold value of £20,000 per QALY) was over 80 %. There was no evidence that three sessions conferred additional benefits, including cost-effectiveness, over one. A single session of breathing training seems appropriate and minimises patient burden. Registry: ISRCTN; ISRCTN49387307; http://www.isrctn.com/ISRCTN49387307 ; registration date: 25/01/2011.
Ankle Injury Management (AIM): design of a pragmatic multi-centre equivalence randomised controlled trial comparing Close Contact Casting (CCC) to Open surgical Reduction and Internal Fixation (ORIF) in the treatment of unstable ankle fractures in patients over 60 years.

PubMed

Willett, Keith; Keene, David J; Morgan, Lesley; Gray, Bridget; Handley, Robert; Chesser, Tim; Pallister, Ian; Tutton, Elizabeth; Knox, Christopher; Lall, Ranjit; Briggs, Andrew; Lamb, Sarah E

2014-03-12

Ankle fractures account for 9% of all fractures with a quarter of these occurring in adults over 60 years. The short term disability and long-term consequences of this injury can be considerable. Current opinion favours open reduction and internal fixation (ORIF) over non-operative treatment (fracture manipulation and the application of a standard moulded cast) for older people. Both techniques are associated with complications but the limited published research indicates higher complication rates of fracture malunion (poor position at healing) with casting. The aim of this study is to compare ORIF with a modification of existing casting techniques, Close Contact Casting (CCC). We propose that CCC may offer an equivalent functional outcome to ORIF and avoid the risks associated with surgery. This study is a pragmatic multi-centre equivalence randomised controlled trial. 620 participants will be randomised to receive ORIF or CCC after sustaining an isolated displaced unstable ankle fracture. Participants will be recruited from a minimum of 20 National Health Service (NHS) acute hospitals throughout England and Wales. Participants will be aged over 60 years and be ambulatory prior to injury. Follow-up will be at six weeks and six months after randomisation. The primary outcome is the Olerud & Molander Ankle Score, a functional patient reported outcome measure, at 6 months. Follow-up will also include assessments of mobility, ankle range of movement, health related quality of life and complications. The six-month follow-up will be conducted face-to-face by an assessor blinded to the allocated intervention. A parallel economic evaluation will consider both a health service and a broader societal perspective including the individual and their family. In order to explore patient experience of their treatment and recovery, a purposive sample of 40 patients will also be interviewed using a semi-structured interview schedule between 6-10 weeks post treatment. This multicentre study was open to recruitment July 2010 and recruitment is due to be completed in December 2013. Current Controlled Trials ISRCTN04180738.
Sample size calculations for stepped wedge and cluster randomised trials: a unified approach

PubMed Central

Hemming, Karla; Taljaard, Monica

2016-01-01

Objectives To clarify and illustrate sample size calculations for the cross-sectional stepped wedge cluster randomized trial (SW-CRT) and to present a simple approach for comparing the efficiencies of competing designs within a unified framework. Study Design and Setting We summarize design effects for the SW-CRT, the parallel cluster randomized trial (CRT), and the parallel cluster randomized trial with before and after observations (CRT-BA), assuming cross-sectional samples are selected over time. We present new formulas that enable trialists to determine the required cluster size for a given number of clusters. We illustrate by example how to implement the presented design effects and give practical guidance on the design of stepped wedge studies. Results For a fixed total cluster size, the choice of study design that provides the greatest power depends on the intracluster correlation coefficient (ICC) and the cluster size. When the ICC is small, the CRT tends to be more efficient; when the ICC is large, the SW-CRT tends to be more efficient and can serve as an alternative design when the CRT is an infeasible design. Conclusion Our unified approach allows trialists to easily compare the efficiencies of three competing designs to inform the decision about the most efficient design in a given scenario. PMID:26344808
Robust mode space approach for atomistic modeling of realistically large nanowire transistors

NASA Astrophysics Data System (ADS)

Huang, Jun Z.; Ilatikhameneh, Hesameddin; Povolotskyi, Michael; Klimeck, Gerhard

2018-01-01

Nanoelectronic transistors have reached 3D length scales in which the number of atoms is countable. Truly atomistic device representations are needed to capture the essential functionalities of the devices. Atomistic quantum transport simulations of realistically extended devices are, however, computationally very demanding. The widely used mode space (MS) approach can significantly reduce the numerical cost, but a good MS basis is usually very hard to obtain for atomistic full-band models. In this work, a robust and parallel algorithm is developed to optimize the MS basis for atomistic nanowires. This enables engineering-level, reliable tight binding non-equilibrium Green's function simulation of nanowire metal-oxide-semiconductor field-effect transistor (MOSFET) with a realistic cross section of 10 nm × 10 nm using a small computer cluster. This approach is applied to compare the performance of InGaAs and Si nanowire n-type MOSFETs (nMOSFETs) with various channel lengths and cross sections. Simulation results with full-band accuracy indicate that InGaAs nanowire nMOSFETs have no drive current advantage over their Si counterparts for cross sections up to about 10 nm × 10 nm.
EVerT2—needling versus non-surgical debridement for the treatment of verrucae: study protocol for a single-centre randomised controlled trial

PubMed Central

Hashmi, Farina; Torgerson, David; Fairhurst, Caroline; Cockayne, Sarah; Bell, Kerry; Cullen, Michelle; Harrison-Blount, Michael

2015-01-01

Introduction Verrucae are extremely common, and are experienced by most people at some time during their lives. Although most verrucae will spontaneously disappear without treatment, many patients seek treatment, often because they have persisted for many years, are unsightly or painful or prevent them from doing sports or other activities. There are many different treatments available; including the Falknor's needling procedure. To date, there has only been one small trial evaluating the clinical effectiveness of this treatment and no health economic analysis has been undertaken. The Effective Verruca Treatments (EVerT2) trial aims to evaluate the clinical and cost-effectiveness of the needling procedure for the treatment of verrucae. Methods and analysis This single-centre randomised controlled trial will recruit 58 participants (aged 18 years and over with a plantar verruca) from Salford Podiatry Clinic patient lists and the surrounding area. If the participant presents with multiple verrucae, an ‘index’ verruca (largest and thickest lesion) will be identified and patients will be randomised 1:1 to the intervention group to receive the needling treatment or the control group to have the callus overlying the verruca debrided. The primary outcome is complete clearance of the index verruca at 12 weeks after randomisation. Secondary outcomes include clearance and recurrence of the treated verruca, clearance of all verrucae, number of verrucae remaining, change in size of the index verruca, pain, and participant satisfaction. A cost-effectiveness analysis of the needling versus callus debridement will be carried out from the perspective of health services over a time horizon of 12 weeks. Ethics and dissemination Ethical approval has been obtained from the University of Salford, Department of Health Sciences Ethical Approval Committee (HSCR15/24) and the University of York, Department of Health Sciences Research Governance Committee (HSRGC/2014/98/B). Findings will be disseminated through publication and conference presentations. Trial registration number ISRCTN16429440. PMID:26603251
Visually Impaired OLder people's Exercise programme for falls prevenTion (VIOLET): a feasibility study protocol

PubMed Central

Skelton, Dawn A; Bailey, Cathy; Howel, Denise; Cattan, Mima; Deary, Vincent; Coe, Dot; de Jong, Lex D; Gawler, Sheena; Gray, Joanne; Lampitt, Rosy; Wilkinson, Jennifer; Adams, Nicola

2016-01-01

Introduction In the UK, 1 in 5 people aged 75 and over live with sight loss. Visually impaired older people (VIOP) have an above average incidence of falls and 1.3–1.9 times more likely to experience hip fractures, than the general population. Older people with eye diseases are ∼3 times more likely than those with good vision, to limit activities due to fear of falling. This feasibility study aims to adapt the group-based Falls Management Exercise (FaME) programme to the needs of VIOP and carry out an external pilot trial to inform the design of a future definitive randomised controlled trial. Methods and design A UK based 2-centre mixed methods, randomised, feasibility study will be conducted over 28 months. Stakeholder panels, including VIOP, will make recommendations for adaptations to an existing exercise programme (FaME), to meet the needs of VIOP, promoting uptake and adherence, while retaining required effective components of the exercise programme. 80 VIOP aged 60 and over, living at home, ambulant with or without a walking aid, will be recruited in Newcastle (n=40) and Glasgow (n=40) through National Health Service (NHS) Trusts and third sector partners. Participants randomised into the intervention arm will receive the adapted FaME programme. Participants randomised into the control arm will continue with usual activity. Outcomes are, recruitment rate, adherence and validated measures including fear of falling and quality of life. Postintervention in-depth qualitative interviews will be conducted with a purposive sample of VIOP (N=10). Postural stability instructors will be interviewed, before trial-specific training and following the intervention. Ethics and dissemination Ethics approval was secured through the National Research Ethics Service (NRES) Committee North East, Newcastle and North Tyneside 2. Glasgow Caledonian University was approved as a non-NHS site with local ethics approval. Findings will be disseminated through peer-reviewed journals, national and international conferences. Trial registration number ISRCTN16949845. PMID:27486124
SWMF Global Magnetosphere Simulations of January 2005: Geomagnetic Indices and Cross-Polar Cap Potential

DOE PAGES

Haiducek, John D.; Welling, Daniel T.; Ganushkina, Natalia Y.; ...

2017-10-30

We simulated the entire month of January, 2005 using the Space Weather Modeling Framework (SWMF) with observed solar wind data as input. We conducted this simulation with and without an inner magnetosphere model, and tested two different grid resolutions. We evaluated the model's accuracy in predicting Kp, Sym-H, AL, and cross polar cap potential (CPCP). We find that the model does an excellent job of predicting the Sym-H index, with an RMSE of 17-18 nT. Kp is predicted well during storm-time conditions, but over-predicted during quiet times by a margin of 1 to 1.7 Kp units. AL is predicted reasonablymore » well on average, with an RMSE of 230-270 nT. However, the model reaches the largest negative AL values significantly less often than the observations. The model tended to over-predict CPCP, with RMSE values on the order of 46-48 kV. We found the results to be insensitive to grid resoution, with the exception of the rate of occurrence for strongly negative AL values. As a result, the use of the inner magnetosphere component, however, affected results significantly, with all quantities except CPCP improved notably when the inner magnetosphere model was on.« less
SWMF Global Magnetosphere Simulations of January 2005: Geomagnetic Indices and Cross-Polar Cap Potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haiducek, John D.; Welling, Daniel T.; Ganushkina, Natalia Y.

We simulated the entire month of January, 2005 using the Space Weather Modeling Framework (SWMF) with observed solar wind data as input. We conducted this simulation with and without an inner magnetosphere model, and tested two different grid resolutions. We evaluated the model's accuracy in predicting Kp, Sym-H, AL, and cross polar cap potential (CPCP). We find that the model does an excellent job of predicting the Sym-H index, with an RMSE of 17-18 nT. Kp is predicted well during storm-time conditions, but over-predicted during quiet times by a margin of 1 to 1.7 Kp units. AL is predicted reasonablymore » well on average, with an RMSE of 230-270 nT. However, the model reaches the largest negative AL values significantly less often than the observations. The model tended to over-predict CPCP, with RMSE values on the order of 46-48 kV. We found the results to be insensitive to grid resoution, with the exception of the rate of occurrence for strongly negative AL values. As a result, the use of the inner magnetosphere component, however, affected results significantly, with all quantities except CPCP improved notably when the inner magnetosphere model was on.« less
Treatment of contact lens related dry eye with antibacterial honey.

PubMed

Wong, Daniel; Albietz, Julie M; Tran, Huan; Du Toit, Cimonette; Li, Anita Hui; Yun, Tina; Han, Jee; Schmid, Katrina L

2017-12-01

Contact lens induced dry eye affects approximately 50% of contact lens wearers. The aim was to assess the effects of Manuka (Leptospermum sp.) honey eye drops (Optimel, Melcare, Australia) on dry eye in contact lens wearers. The safety of the honey eye drops in contact lens wear and contact lens wearers' compliance were also evaluated. Prospective, randomised, cross over study, examiner masked, pilot treatment trial. Twenty-four participants aged 20 to 55 years with contact lens related dry eye were recruited and randomised to two treatment groups; 20 completed the study. One group used Optimel eye drops twice a day for two weeks followed by conventional lubricant (Systane Ultra, Alcon) therapy for two weeks; the other group completed the treatments in the reverse order. Before and after each treatment dry eye symptomology, ocular surface inflammation, and tear quantity and quality were assessed. Participants completed a daily log detailing their usage of treatments and any issues. Dry eye symptoms improved significantly after Optimel treatment. Patients with more severe symptoms at baseline showed a greater improvement in symptoms. No significant differences were observed in the objective signs of dry eye; presumably because of the short treatment duration. Seventy-five% of contact lens wearers reported good adherence to Optimel treatment and 95% reported no issues using this product. Optimel Eye Drops reduce the symptoms of dry eye in contact lens wearers and are safe to use. A longer treatment period to assess the effect on clinical signs of dry eye is required. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
No effects of 20 Hz-rTMS of the primary motor cortex in vegetative state: A randomised, sham-controlled study.

PubMed

Cincotta, Massimo; Giovannelli, Fabio; Chiaramonti, Roberta; Bianco, Giovanni; Godone, Marco; Battista, Donato; Cardinali, Consuelo; Borgheresi, Alessandra; Sighinolfi, Antonella; D'Avanzo, Anna Maria; Breschi, Marco; Dine, Ylli; Lino, Mario; Zaccara, Gaetano; Viggiano, Maria Pia; Rossi, Simone

2015-10-01

We assessed the effects of a non-invasive neuromodulatory intervention with repetitive transcranial magnetic stimulation (rTMS) of the motor cortex in patients with vegetative state (VS) by a randomised, sham-controlled study with a cross-over design. Eleven patients classified as being in VS (9 post-anoxic, 2 post-traumatic, time elapsed from the injury 9-85 months) were included in the study. Real or sham 20 Hz rTMS were applied to the left primary motor cortex (M1) for 5 consecutive days. Primary outcome measures were changes in the JFK Coma Recovery Scale-Revised (CRS-R) scale total score and Clinical Global Impression Improvement (CGI-I) scale. Additional measures were EEG changes and impression of the patients' relatives using the CGI-I scale. Evaluations were blindly performed at baseline, after the first day of treatment, immediately after the end of the 5-days treatment, 1 week and 1 month later. Slight changes observed in the CRS-R and CGI-I scores did not significantly differ between real or sham stimulation conditions. EEG was not significantly changed on average, although spots of brain reactivity were occasionally found underneath the stimulation point. Findings did not provide evidence of therapeutic effect of 20 Hz rTMS of the M1 in chronic VS, at least with conventional coils and current safety parameters. Therefore, they might be useful to better allocate human and financial resources in future trials. Copyright © 2015 Elsevier Ltd. All rights reserved.
Impact of High-Intensity-NIV on the heart in stable COPD: a randomised cross-over pilot study.

PubMed

Duiverman, Marieke Leontine; Maagh, Petra; Magnet, Friederike Sophie; Schmoor, Claudia; Arellano-Maric, Maria Paola; Meissner, Axel; Storre, Jan Hendrik; Wijkstra, Peter Jan; Windisch, Wolfram; Callegari, Jens

2017-05-02

Although high-intensity non-invasive ventilation has been shown to improve outcomes in stable COPD, it may adversely affect cardiac performance. Therefore, the aims of the present pilot study were to compare cardiac and pulmonary effects of 6 weeks of low-intensity non-invasive ventilation and 6 weeks of high-intensity non-invasive ventilation in stable COPD patients. In a randomised crossover pilot feasibility study, the change in cardiac output after 6 weeks of each NIV mode compared to baseline was assessed with echocardiography in 14 severe stable COPD patients. Furthermore, CO during NIV, gas exchange, lung function, and health-related quality of life were investigated. Three patients dropped out: two deteriorated on low-intensity non-invasive ventilation, and one presented with decompensated heart failure while on high-intensity non-invasive ventilation. Eleven patients were included in the analysis. In general, cardiac output and NTproBNP did not change, although individual effects were noticed, depending on the pressures applied and/or the co-existence of heart failure. High-intensity non-invasive ventilation tended to be more effective in improving gas exchange, but both modes improved lung function and the health-related quality of life. Long-term non-invasive ventilation with adequate pressure to improve gas exchange and health-related quality of life did not have an overall adverse effect on cardiac performance. Nevertheless, in patients with pre-existing heart failure, the application of very high inspiratory pressures might reduce cardiac output. The trial was registered in the Deutsches Register Klinischer Studien (DRKS-ID: DRKS00007977 ).
Inflammatory markers in a randomised soya intervention among men.

PubMed

Maskarinec, Gertraud; Oum, Robert; Chaptman, Ann K; Ognjanovic, Simona

2009-06-01

The present analysis investigated the effect of soya foods on serum levels of six inflammatory markers, leptin, adiponectin, monocyte attractant protein 1 (MCP-1), macrophage inflammatory protein-1b (MIP-1b), IL-6 and C-reactive protein (CRP), and their relationship with BMI and lifetime soya intake. We randomised twenty-four men to a high- (two daily servings with 30-35 mg isoflavones per serving) or a low-soya diet for 3 months. After a 1-month washout period, the men crossed over to the other treatment. We used a multiplex bead immunoassay to measure leptin, adiponectin, MCP-1 and MIP-1b and ELISA assays for IL-6 and CRP. The statistical analysis applied mixed models that incorporated the four repeated measurements. The men had a mean age of 58.7 (sd 7.2) years and a mean BMI of 28.4 (sd 4.9) kg/m2. We observed no significant intervention effect of the soya treatment on any of the six markers. After adjustment for age and ethnicity, highly significant associations of BMI and body weight with leptin and MCP-1 emerged. Men with high soya intake early in life also had higher levels of leptin and MCP-1, whereas no association was seen for soya intake during adulthood. MIP-1b, adiponectin, IL-6 and CRP were not related to BMI, body weight or soya intake at any time in life. No intervention effect of soya foods on markers of inflammation was observed in this small study, but adiposity and early-life soya intake were related to higher leptin and MCP-1 levels.
Complex behaviour in complex terrain - Modelling bird migration in a high resolution wind field across mountainous terrain to simulate observed patterns.

PubMed

Aurbach, Annika; Schmid, Baptiste; Liechti, Felix; Chokani, Ndaona; Abhari, Reza

2018-06-03

Crossing of large ecological barriers, such as mountains, is in terms of energy considered to be a demanding and critical step during bird migration. Besides forming a geographical barrier, mountains have a profound impact on the resulting wind flow. We use a novel framework of mathematical models to investigate the influences of wind and topography on nocturnal passerine bird behaviour, and to assess the energy costs for different flight strategies for crossing the Jura Mountains. The mathematical models include three biological models of bird behaviour: i) wind drift compensation; ii) adaptation of flight height for favourable winds; and, iii) avoidance of obstacles (cross over and/or circumvention of an obstacle following a minimum energy expenditure strategy), which are assessed separately and in combination. Further, we use a mesoscale weather model for high-resolution predictions of the wind fields. We simulate the broad front nocturnal passerine migration for autumn nights with peak migration intensities. The bird densities retrieved from a weather radar are used as the initial intensities and to specify the vertical distributions of the simulated birds. It is shown that migration over complex terrain represents the most expensive flight option in terms of energy expenditure, and wind is seen to be the main factor that influences the energy expenditure in the bird's preferred flight direction. Further, the combined effects of wind and orography lead to a high concentration of migratory birds within the favourable wind conditions of the Swiss lowlands and north of the Jura Mountains. Copyright © 2018 Elsevier Ltd. All rights reserved.

Managing uncertainty - a qualitative study of surgeons' decision-making for one-stage and two-stage revision surgery for prosthetic hip joint infection.

PubMed

Moore, Andrew J; Blom, Ashley W; Whitehouse, Michael R; Gooberman-Hill, Rachael

2017-04-12

Approximately 88,000 primary hip replacements are performed in England and Wales each year. Around 1% go on to develop deep prosthetic joint infection. Between one-stage and two-stage revision arthroplasty best treatment options remain unclear. Our aims were to characterise consultant orthopaedic surgeons' decisions about performing either one-stage or two-stage revision surgery for patients with deep prosthetic infection (PJI) after hip arthroplasty, and to identify whether a randomised trial comparing one-stage with two-stage revision would be feasible. Semi-structured interviews were conducted with 12 consultant surgeons who perform revision surgery for PJI after hip arthroplasty at 5 high-volume National Health Service (NHS) orthopaedic departments in England and Wales. Surgeons were interviewed before the development of a multicentre randomised controlled trial. Data were analysed using a thematic approach. There is no single standardised surgical intervention for the treatment of PJI. Surgeons balance multiple factors when choosing a surgical strategy which include multiple patient-related factors, their own knowledge and expertise, available infrastructure and the infecting organism. Surgeons questioned whether it was appropriate that the two-stage revision remained the best treatment, and some surgeons' willingness to consider more one-stage revisions had increased over recent years and were influenced by growing evidence showing equivalence between surgical techniques, and local observations of successful one-stage revisions. Custom-made articulating spacers was a practice that enabled uncertainty to be managed in the absence of definitive evidence about the superiority of one surgical technique over the other. Surgeons highlighted the need for research evidence to inform practice and thought that a randomised trial to compare treatments was needed. Most surgeons thought that patients who they treated would be eligible for trial participation in instances where there was uncertainty about the best treatment option. Surgeons highlighted the need for evidence to support their choice of revision. Some surgeons' willingness to consider one-stage revision for infection had increased over time, largely influenced by evidence of successful one-stage revisions. Custom-made articulating spacers also enabled surgeons to manage uncertainty about the superiority of surgical techniques. Surgeons thought that a prospective randomised controlled trial comparing one-stage with two-stage joint replacement is needed and that randomisation would be feasible.
Assessment of Flood Mitigation Solutions Using a Hydrological Model and Refined 2D Hydrodynamic Simulations

NASA Astrophysics Data System (ADS)

Khuat Duy, B.; Archambeau, P.; Dewals, B. J.; Erpicum, S.; Pirotton, M.

2009-04-01

Following recurrent inundation problems on the Berwinne catchment, in Belgium, a combined hydrologic and hydrodynamic study has been carried out in order to find adequate solutions for the floods mitigation. Thanks to detailed 2D simulations, the effectiveness of the solutions can be assessed not only in terms of discharge and height reductions in the river, but also with other aspects such as the inundated surfaces reduction and the decrease of inundated buildings and roads. The study is carried out in successive phases. First, the hydrological runoffs are generated using a physically based and spatially distributed multi-layer model solving depth-integrated equations for overland flow, subsurface flow and baseflow. Real floods events are simulated using rainfall series collected at 8 stations (over 20 years of available data). The hydrological inputs are routed through the river network (and through the sewage network if relevant) with the 1D component of the modelling system, which solves the Saint-Venant equations for both free-surface and pressurized flows in a unified way. On the main part of the river, the measured river cross-sections are included in the modelling, and existing structures along the river (such as bridges, sluices or pipes) are modelled explicitely with specific cross sections. Two gauging stations with over 15 years of continuous measurements allow the calibration of both the hydrologic and hydrodynamic models. Second, the flood mitigation solutions are tested in the simulations in the case of an extreme flooding event, and their effects are assessed using detailed 2D simulations on a few selected sensitive areas. The digital elevation model comes from an airborne laser survey with a spatial resolution of 1 point per square metre and is completed in the river bed with a bathymetry interpolated from cross-section data. The upstream discharge is extracted from the 1D simulation for the selected rainfall event. The study carried out with this methodology allowed to assess the suggested solutions with multiple effectiveness criteria and therefore constitutes a very useful support for decision makers.
Extension of the Haseman-Elston regression model to longitudinal data.

PubMed

Won, Sungho; Elston, Robert C; Park, Taesung

2006-01-01

We propose an extension to longitudinal data of the Haseman and Elston regression method for linkage analysis. The proposed model is a mixed model having several random effects. As response variable, we investigate the sibship sample mean corrected cross-product (smHE) and the BLUP-mean corrected cross product (pmHE), comparing them with the original squared difference (oHE), the overall mean corrected cross-product (rHE), and the weighted average of the squared difference and the squared mean-corrected sum (wHE). The proposed model allows for the correlation structure of longitudinal data. Also, the model can test for gene x time interaction to discover genetic variation over time. The model was applied in an analysis of the Genetic Analysis Workshop 13 (GAW13) simulated dataset for a quantitative trait simulating systolic blood pressure. Independence models did not preserve the test sizes, while the mixed models with both family and sibpair random effects tended to preserve size well. Copyright 2006 S. Karger AG, Basel.
Understanding the role of moisture transport on the dry bias in indian monsoon simulations by CFSv2

NASA Astrophysics Data System (ADS)

Sahana, A. S.; Pathak, Amey; Roxy, M. K.; Ghosh, Subimal

2018-02-01

We analyse the bias present in the Indian Summer Monsoon Rainfall (ISMR), as simulated by Climate Forecast System Model 2 (CFSv2), the operational model used for monsoon forecasts in India. In the simulations, the precipitation intensity is redistributed within the ITCZ band with southward shifts of precipitation maxima. We observe weakening of maximum intensity of precipitation over the region between 20°N and 14°N. In the simulations by CFSv2, there exists two rain bands: the northern one located slightly southward compared to reanalysis dataset and the southern one over the equator with intensified precipitation. This results in dry bias over land and wet bias over the ocean. We use a Dynamic Recycling Model, based on Lagrangian approach, to investigate the role of various moisture sources in generating these biases. We find that, the dry bias during June exists due to the delayed monsoon onset and reduced moisture flow from the Arabian Sea. As the monsoon progresses, deficiency in the simulated contributions from South Indian Ocean becomes the key source of bias. The reduced supply of moisture from oceanic sources is primarily attributed to the weaker northward transport of moisture flux from the Southern Ocean, associated with a weaker southward energy flux. Inefficiency of the model in simulating the heating in Tibetan plateau during the pre-monsoon period leads to this reduced cross equatorial energy flow. We also find that, towards the end of monsoon season, moisture contributions from land sources namely, Ganga Basin and North-Eastern forests become significant and underestimations of the same in the simulations by CFSv2 result into biases over Central and Eastern India.
Baclofen for alcohol withdrawal.

PubMed

Liu, Jia; Wang, Lu-Ning

2017-08-20

Baclofen shows potential for rapidly reducing symptoms of severe alcohol withdrawal syndrome (AWS) in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane Review published in 2015, Issue 4. To assess the efficacy and safety of baclofen for people with AWS. We updated our searches of the following databases to March 2017: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, PubMed, Embase, and CINAHL. We also searched registers of ongoing trials. We handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language. We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies. We used standard methodological procedures expected by Cochrane. We included three RCTs with 141 randomised participants. We did not perform meta-analyses due to the different control interventions. For the comparison of baclofen and placebo (1 study, 31 participants), there was no significant difference in Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) scores (very low quality evidence). For the comparison of baclofen and diazepam (1 study, 37 participants), there was no significant difference in CIWA-Ar scores (very low quality evidence), adverse events (risk difference (RD) 0.00, 95% confidence interval (CI) -0.10 to 0.10; very low quality evidence), dropouts (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence). For the comparison of baclofen and chlordiazepoxide (1 study, 60 participants), there was no significant difference in CIWA-Ar scores (mean difference (MD) 1.00, 95% CI 0.70 to 1.30; very low quality evidence), global improvement (MD 0.10, 95% CI -0.03 to 0.23; very low quality evidence), adverse events (RD 2.50, 95% CI 0.88 to 7.10; very low quality of evidence), dropouts (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence). No conclusions can be drawn about the efficacy and safety of baclofen for the management of alcohol withdrawal because we found insufficient and very low quality evidence.
Early light reduction for preventing retinopathy of prematurity in very low birth weight infants.

PubMed

Jorge, Eliane C; Jorge, Edson N; El Dib, Regina P

2013-08-06

Retinopathy of prematurity (ROP) is a complex condition of the developing retinal blood vessels and is one of the leading causes of preventable childhood blindness. Several risk factors for ROP have been studied over the past 50 years. Among them, general immaturity (low birth weight and low gestational age) and prolonged oxygen therapy have been consistently related to disease onset. However, it is understood that the progression of the disease is multifactorial and may be associated with others risk factors, such as multiple gestation, apnoea, intracranial haemorrhage, anaemia, sepsis, prolonged mechanical ventilation, multiple transfusions and light exposure. Furthermore, the precise role of these individual factors in the development of the disease has not yet been well established. To determine whether the reduction of early environmental light exposure reduces the incidence of retinopathy of prematurity (ROP) or poor ROP outcomes among very low birth weight infants. We searched the following databases: the Cochrane Neonatal Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, HealthSTAR, Science Citation Index Database, CANCERLIT, the Oxford Database of Perinatal Trials and www.clinicaltrials.gov. We also searched previous reviews including cross-references, abstracts, conference and symposia proceedings, and contacted expert informants. This search was updated in October 2012. Randomised or quasi-randomised controlled trials that reduced light exposure to premature infants within the first seven days following birth were considered for this review. We also considered cluster-randomised controlled trials. Data on clinical outcomes including any acute ROP and poor ROP outcome were extracted by both review authors independently and consensus reached. We conducted data analysis according to the standards of the Cochrane Neonatal Review Group. Data from four randomised trials with a total of 897 participants failed to show any reduction in acute ROP or poor ROP outcome with the reduction of ambient light to premature infants' retinas. The overall methodological quality of the included studies was about evenly split between those in which the classification was unclear and those in which the studies were categorised as low risk of bias. There was no report on the secondary outcomes considered in this review: quality of life measures; and time of exposure to oxygen. The evidence shows that bright light is not the cause of retinopathy of prematurity and that the reduction of exposure of the retinas of premature infants to light has no effect on the incidence of the disease.
Comparison of pain response after subcutaneous injection of two maropitant formulations to beagle dogs.

PubMed

Deckers, Nynke; Ruigrok, Catharina A; Verhoeve, Hans Peter; Lourens, Nicky

2018-01-01

The antiemetic maropitant, with metacresol as preservative (Cerenia, Zoetis), has been associated with pain after subcutaneous injection in dogs and cats. Recently, a generic formulation containing benzyl alcohol was authorised (Prevomax, Le Vet). Benzyl alcohol is reported to have local anaesthetic properties and reduce injection pain. This study compared local pain after subcutaneous injection of the two maropitant formulations, administered at approximately 4°C and 25°C, to dogs. Thirty-two healthy beagle dogs were enrolled into a blinded, randomised, cross-over study. Dogs received subcutaneous injections of maropitant injection containing metacresol as preservative and maropitant injection containing benzyl alcohol as preservative, both at approximately 4°C and 25°C, with at least three days in between treatments. Injection pain was evaluated by two blinded observers using a visual analogue scale immediately after injection and a simple descriptive scale at two minutes after injection. In healthy beagle dogs, subcutaneous injection of maropitant with benzyl alcohol is significantly less painful than injection of maropitant with metacresol.
Influence of low versus moderate glycemic index of diet on substrate oxidation and energy expenditure during incremental exercise in endurance athletes: a randomized counterbalanced cross-over trial.

PubMed

Durkalec-Michalski, Krzysztof; Zawieja, Emilia Ewa; Zawieja, Bogna Ewa; Podgórski, Tomasz; Jurkowska, Dominika; Jeszka, Jan

2017-12-18

The study was aimed at assessing the influence of 3-week low glycemic index (LGI) versus moderate glycemic index (MGI) diet on substrate oxidation during incremental exercise. 17 runners completed two 3-week trials of either LGI or MGI diet in a randomised counterbalanced manner. Before and after each trial the incremental cycling test was performed. Metabolic alternations were observed only within tested diets and no significant differences in fat and carbohydrate (CHO) oxidation were found between MGI and LGI diets. Following MGI diet CHO oxidation rate increased. The AUC of fat oxidation decreased after both diets. Percent contribution of fat to energy yield declined, whereas contribution of CHO was augmented following MGI diet. This study indicates that the 3-week MGI diet increased the rate of carbohydrate oxidation during incremental cycling test and improved performance in acute intense exercise test, while both high-carbohydrate diets downregulated fat oxidation rate.
Randomised studies of income supplementation: a lost opportunity to assess health outcomes.

PubMed

Connor, J; Rodgers, A; Priest, P

1999-11-01

Despite the wealth of evidence linking low income to ill health, there is little information from randomised studies on how much and how quickly these risks can be reversed by improvements in income. To conduct a systematic review of randomised studies of income supplementation, with particular reference to health outcomes. Extensive searches of electronic databases and contact with previous authors. As well as searching for trials that were specifically designed to assess the effects of increased income, studies of winners and losers of lotteries were also sought: if winning is purely chance, such studies are, in effect, randomised trials of increased income. Ten relevant studies were identified, all conducted in North America, mostly in the late 1960s and 1970s. Five trials were designed to assess the effects of income supplementation on workforce participation and randomised a total of 10,000 families to 3-5 years of various combinations of minimum income guarantees and reduced tax rates. Two trials were designed to assess re-offending rates in recently released prisoners and randomised a total of 2400 people to 3-6 months of benefits. One trial was designed to assess housing allowances and randomised 3500 families to three years of income supplements. One trial assessed the health effects of 12 months of income supplementation in 54 people with severe mental illness. Finally, one study compared three groups of people who won different amounts of money in a state lottery. In all these studies the interventions resulted in increases in income of at least one fifth. However, no reliable analyses of health outcome data are available. Extensive opportunities to reliably assess the effects of increases in income on health outcomes have been missed. Such evidence might have increased the consideration of potential health effects during deliberations about policies that have major implications for income, such as taxation rates, benefit policies, and minimum wage levels. Randomised evidence could still be obtained with innovative new studies, such as trials of full benefit uptake or prospective studies of lottery winners in which different sized winnings are paid in monthly installments over many years.
How did a Housing First intervention improve health and social outcomes among homeless adults with mental illness in Toronto? Two-year outcomes from a randomised trial

PubMed Central

O'Campo, Patricia; Stergiopoulos, Vicky; Nir, Pam; Levy, Matthew; Misir, Vachan; Chum, Antony; Arbach, Bouchra; Nisenbaum, Rosane; To, Matthew J; Hwang, Stephen W

2016-01-01

Objectives We studied the impact of a Housing First (HF) intervention on housing, contact with the justice system, healthcare usage and health outcomes among At Home/Chez Soi randomised trial participants in Toronto, a city with an extensive service network for social and health services for individuals who are experiencing homelessness and mental illness. Methods Participants identified as high needs were randomised to receive either the intervention which provided them with housing and supports by an assertive community treatment team (HF+ACT) or treatment as usual (TAU). Participants (N=197) had in-person interviews every 3 months for 2 years. Results The HF+ACT group spent more time stably housed compared to the TAU group with the mean difference between the groups of 45.8% (95% CI 37.1% to 54.4%, p<0.0001). Accounting for baseline differences, HF+ACT group showed significant improvements over TAU group for community functioning, selected quality-of-life subscales and arrests at some time points during follow-up. No differences between HF+ACT and TAU groups over the follow-up were observed for health service usage, community integration and substance use. Conclusions HF for individuals with high levels of need increased housing stability and selected health and justice outcomes over 2 years in a city with many social and health services. Trial registration number ISRCTN42520374. PMID:27619826
Efficacy of infant simulator programmes to prevent teenage pregnancy: a school-based cluster randomised controlled trial in Western Australia.

PubMed

Brinkman, Sally A; Johnson, Sarah E; Codde, James P; Hart, Michael B; Straton, Judith A; Mittinty, Murthy N; Silburn, Sven R

2016-11-05

Infant simulator-based programmes, which aim to prevent teenage pregnancy, are used in high-income as well as low-income and middle-income countries but, despite growing popularity, no published evidence exists of their long-term effect. The aim of this trial was to investigate the effect of such a programme, the Virtual Infant Parenting (VIP) programme, on pregnancy outcomes of birth and induced abortion in Australia. In this school-based pragmatic cluster randomised controlled trial, eligible schools in Perth, Western Australia, were enrolled and randomised 1:1 to the intervention and control groups. Randomisation using a table of random numbers without blocking, stratification, or matching was done by a researcher who was masked to the identity of the schools. Between 2003 and 2006, the VIP programme was administered to girls aged 13-15 years in the intervention schools, while girls of the same age in the control schools received the standard health education curriculum. Participants were followed until they reached 20 years of age via data linkage to hospital medical and abortion clinic records. The primary endpoint was the occurrence of pregnancy during the teenage years. Binomial and Cox proportional hazards regression was used to test for differences in pregnancy rates between study groups. This study is registered as an international randomised controlled trial, number ISRCTN24952438. 57 (86%) of 66 eligible schools were enrolled into the trial and randomly assigned 1:1 to the intervention (28 schools) or the control group (29 schools). Then, between Feb 1, 2003, and May 31, 2006, 1267 girls in the intervention schools received the VIP programme while 1567 girls in the control schools received the standard health education curriculum. Compared with girls in the control group, a higher proportion of girls in the intervention group recorded at least one birth (97 [8%] of 1267 in the intervention group vs 67 [4%] of 1567 in the control group) or at least one abortion as the first pregnancy event (113 [9%] vs 101 [6%]). After adjustment for potential confounders, the intervention group had a higher overall pregnancy risk than the control group (relative risk 1·36 [95% CI 1·10-1·67], p=0·003). Similar results were obtained with the use of proportional hazard models (hazard ratio 1·35 [95% CI 1·10-1·67], p=0·016). The infant simulator-based VIP programme did not achieve its aim of reducing teenage pregnancy. Girls in the intervention group were more likely to experience a birth or an induced abortion than those in the control group before they reached 20 years of age. Western Australian Health Promotion Foundation (Healthway), Lotteries WA, the Western Australian Department of Education and Training, and the Western Australian Department of Health. Copyright © 2016 Elsevier Ltd. All rights reserved.
Antibiotics in periodontal surgeries: A prospective randomised cross over clinical trial

PubMed Central

Oswal, Sheetal; Ravindra, Shivamurthy; Sinha, Aditya; Manjunath, Shaurya

2014-01-01

Aims and Objectives: (1) To evaluate the need of antibiotics in periodontal surgeries in reducing postsurgical infections and explore if antibiotics have any key role in reducing or eliminating inflammatory complications. (2) To establish the incidence of postoperative infections in relation to type of surgery and determine those factors, which may affect infection rates. Materials and Methods: A prospective randomized double-blind cross over clinical study was carried out for a period of 1-year with predefined inclusion and exclusion criteria. All the patients included in the study for any periodontal surgery were randomly divided into three categories: Group A (prophylactic), Group B (therapeutic), and Group C (no antibiotics). Patients were followed up for 1-week after surgery on the day of suture removal and were evaluated for pain, swelling, fever, infection, delayed wound healing and any other significant findings. Appropriate statistical analysis was carried out to evaluate the objectives and P < 0.05 was considered as statistically significant. Results: No infection was reported in any of 90 sites. Patients reported less pain and postoperative discomfort when prophylactic antibiotics were given. However, there were no statistical significant differences between the three groups. Summary and Conclusion: There was no postoperative infection reported in all the 90 sites operated in this study. The prevalence of postoperative infections following periodontal surgery is <1% and this low risk does not justify the routine use of systemic antimicrobials just to prevent infections. Use of prophylactic antibiotics may have role in prevention of inflammatory complication, but again not infection. PMID:25425817
Using environmental engineering to increase hand hygiene compliance: a cross-over study protocol

PubMed Central

Schmidtke, Kelly Ann; Aujla, Navneet; Marshall, Tom; Hussain, Abid; Hodgkinson, Gerard P; Arheart, Kristopher; Marti, Joachim; Birnbach, David J; Vlaev, Ivo

2017-01-01

Introduction Compliance with hand hygiene recommendations in hospital is typically less than 50%. Such low compliance inevitably contributes to hospital-acquired infections that negatively affect patients’ well-being and hospitals’ finances. The design of the present study is predicated on the assumption that most people who fail to clean their hands are not doing so intentionally, they just forget. The present study will test whether psychological priming can be used to increase the number of people who clean their hands on entering a ward. Here, we present the protocol for this study. Methods and analysis The study will use a randomised cross-over design. During the study, each of four wards will be observed during four conditions: olfactory prime, visual prime, both primes and neither prime. Each condition will be experienced for 42 days followed by a 7-day washout period (total duration of trial=189 days). We will record the number of people who enter each ward and whether they clean their hands during observation sessions, the amount of cleaning material used from the dispensers each week and the number of hospital-acquired infections that occur in each period. The outcomes will be compared using a regression analysis. Following the initial trail, the most effective priming condition will be rolled out for 3 months in all the wards. Ethics and dissemination Research ethics approval was obtained from the South Central—Oxford C Research Ethics Committee (16/SC/0554), the Health Regulatory Authority and the sponsor. Trial registration number ISRCTN (15397624); Edge ID 86357. PMID:28893752
Intramyocellular lipid content in subjects with impaired fasting glucose after telmisartan treatment, a randomised cross-over trial.

PubMed

Kratochvílová, Simona; Škoch, Antonín; Wohl, Petr; Švehlíková, Eva; Dezortová, Monika; Hill, Martin; Hájek, Milan; Pelikánová, Terezie

2016-04-01

Ectopic lipid accumulation in skeletal muscle is associated with insulin resistance. Telmisartan improves metabolic parameters in type 2 diabetic patients. The aim of our study was to evaluate the in vivo effect of telmisartan on intramyocellular lipid content (IMCL) in subjects with impaired fasting glucose (IFG) by magnetic resonance spectroscopy (MRS). We enrolled 10 subjects with IFG in a cross-over, placebo-controlled, randomized, double-blind trial, treated with 3 weeks of telmisartan (160 mg daily) or placebo. After completing each treatment, a hyperinsulinaemic euglycaemic clamp (1 mU/kg per min; 5 mmol/l; 120 min) to assess insulin action (metabolic clearance rate of glucose, MCR) and (1)H MRS of the m. tibialis anterior using a MR Scanner Siemens Vision operating at 1.5 T to evaluate IMCL content, were performed. Plasma adipokine levels were determined simultaneously. Telmisartan treatment resulted in a lower fasting plasma glucose (FPG) (p < 0.05), but insulin action was comparable to after placebo. Telmisartan did not affect IMCL content. After placebo, IMCL correlated negatively with total cholesterol (p < 0.001), MCR (p < 0.05) and adiponectin (p < 0.05) and positively with FPG (p < 0.05). After telmisartan treatment there was only a positive correlation between IMCL and TNFα (p < 0.05). IMCL content is related to parameters of glucose metabolism and insulin action in sedentary IFG subjects. A short telmisartan treatment did not affect the IMCL content despite its positive effect on FPG. The improvement in FPG was probably mediated through interference with other metabolic pathways. Copyright © 2015 Elsevier Inc. All rights reserved.
Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study.

PubMed

The, Gerard K H; Verkes, Robbert J; Fekkes, Durk; Bleijenberg, Gijs; van der Meer, Jos W M; Buitelaar, Jan K

2014-09-16

Chronic fatigue syndrome (CFS) is still an enigmatic disorder. CFS can be regarded as a complex disorder with tremendous impact on lives of CFS-patients. Full recovery without treatment is rare. A somatic explanation for the fatigue is lacking. There is clinical and experimental evidence implicating enhanced serotonergic neurotransmission in CFS. Genetic studies and imaging studies support the hypothesis of upregulated serotonin system in CFS. In line with the hypothesis of an increased serotonergic state in CFS, we performed a randomised clinical trial investigated the effect of 5-HT3 receptor antagonism in CFS. No benefit was found of the 5-HT3 receptor antagonist ondansetron compared to placebo.To further investigate the involvement of serotonin in CFS we performed a placebo controlled cross over pilot study investigating the effect of Acute Tryptophan Depletion. Five female CFS-patients who met the US Center for Disease Control and Prevention criteria for CFS were recruited. There were two test days, one week apart. Each participant received placebo and ATD. To evaluate the efficacy of the ATD procedure tryptophan and the large neutral amino acids were measured. The outcome measures were fatigue severity, concentration and mood states. ATD resulted in a significant plasma tryptophan to large neutral amino acid ratio reduction of 96%. There were no significant differences in fatigue-, depression and concentration between the placebo- and ATD condition. These first five CFS-patients did not respond to the ATD procedure. However, a much larger sample size is needed to draw final conclusions on the hypothesis of an increased serotonergic state in the pathophysiology of CFS. ISRCTN07518149.
Promoting Recruitment using Information Management Efficiently (PRIME): a stepped-wedge, cluster randomised trial of a complex recruitment intervention embedded within the REstart or Stop Antithrombotics Randomised Trial.

PubMed

Maxwell, Amy E; Parker, Richard A; Drever, Jonathan; Rudd, Anthony; Dennis, Martin S; Weir, Christopher J; Al-Shahi Salman, Rustam

2017-12-28

Few interventions are proven to increase recruitment in clinical trials. Recruitment to RESTART, a randomised controlled trial of secondary prevention after stroke due to intracerebral haemorrhage, has been slower than expected. Therefore, we sought to investigate an intervention to boost recruitment to RESTART. We conducted a stepped-wedge, cluster randomised trial of a complex intervention to increase recruitment, embedded within the RESTART trial. The primary objective was to investigate if the PRIME complex intervention (a recruitment co-ordinator who conducts a recruitment review, provides access to bespoke stroke audit data exports, and conducts a follow-up review after 6 months) increases the recruitment rate to RESTART. We included 72 hospital sites located in England, Wales, or Scotland that were active in RESTART in June 2015. All sites began in the control state and were allocated using block randomisation stratified by hospital location (Scotland versus England/Wales) to start the complex intervention in one of 12 different months. The primary outcome was the number of patients randomised into RESTART per month per site. We quantified the effect of the complex intervention on the primary outcome using a negative binomial, mixed model adjusting for site, December/January months, site location, and background time trends in recruitment rate. We recruited and randomised 72 sites and recorded their monthly recruitment to RESTART over 24 months (March 2015 to February 2017 inclusive), providing 1728 site-months of observations for the primary analysis. The adjusted rate ratio for the number of patients randomised per month after allocation to the PRIME complex intervention versus control time before allocation to the PRIME complex intervention was 1.06 (95% confidence interval 0.55 to 2.03, p = 0.87). Although two thirds of respondents to the 6-month follow-up questionnaire agreed that the audit reports were useful, only six patients were reported to have been randomised using the audit reports. Respondents frequently reported resource and time pressures as being key barriers to running the audit reports. The PRIME complex intervention did not significantly improve the recruitment rate to RESTART. Further research is needed to establish if PRIME might be beneficial at an earlier stage in a prevention trial or for prevention dilemmas that arise more often in clinical practice.
Shear thinning effects on blood flow in straight and curved tubes

NASA Astrophysics Data System (ADS)

Cherry, Erica M.; Eaton, John K.

2013-07-01

Simulations were performed to determine the magnitude and types of errors one can expect when approximating blood in large arteries as a Newtonian fluid, particularly in the presence of secondary flows. This was accomplished by running steady simulations of blood flow in straight and curved tubes using both Newtonian and shear-thinning viscosity models. In the shear-thinning simulations, the viscosity was modeled as a shear rate-dependent function fit to experimental data. Simulations in straight tubes were modeled after physiologically relevant arterial flows, and flow parameters for the curved tube simulations were chosen to examine a variety of secondary flow strengths. The diameters ranged from 1 mm to 10 mm and the Reynolds numbers from 24 to 1500. Pressure and velocity data are reported for all simulations. In the straight tube simulations, the shear-thinning flows had flattened velocity profiles and higher pressure gradients compared to the Newtonian simulations. In the curved tube flows, the shear-thinning simulations tended to have blunted axial velocity profiles, decreased secondary flow strengths, and decreased axial vorticity compared to the Newtonian simulations. The cross-sectionally averaged pressure drops in the curved tubes were higher in the shear-thinning flows at low Reynolds number but lower at high Reynolds number. The maximum deviation in secondary flow magnitude averaged over the cross sectional area was 19% of the maximum secondary flow and the maximum deviation in axial vorticity was 25% of the maximum vorticity.
Assessment of the effect of larval source management and house improvement on malaria transmission when added to standard malaria control strategies in southern Malawi: study protocol for a cluster-randomised controlled trial.

PubMed

McCann, Robert S; van den Berg, Henk; Diggle, Peter J; van Vugt, Michèle; Terlouw, Dianne J; Phiri, Kamija S; Di Pasquale, Aurelio; Maire, Nicolas; Gowelo, Steven; Mburu, Monicah M; Kabaghe, Alinune N; Mzilahowa, Themba; Chipeta, Michael G; Takken, Willem

2017-09-22

Due to outdoor and residual transmission and insecticide resistance, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) will be insufficient as stand-alone malaria vector control interventions in many settings as programmes shift toward malaria elimination. Combining additional vector control interventions as part of an integrated strategy would potentially overcome these challenges. Larval source management (LSM) and structural house improvements (HI) are appealing as additional components of an integrated vector management plan because of their long histories of use, evidence on effectiveness in appropriate settings, and unique modes of action compared to LLINs and IRS. Implementation of LSM and HI through a community-based approach could provide a path for rolling-out these interventions sustainably and on a large scale. We will implement community-based LSM and HI, as additional interventions to the current national malaria control strategies, using a randomised block, 2 × 2 factorial, cluster-randomised design in rural, southern Malawi. These interventions will be continued for two years. The trial catchment area covers about 25,000 people living in 65 villages. Community participation is encouraged by training community volunteers as health animators, and supporting the organisation of village-level committees in collaboration with The Hunger Project, a non-governmental organisation. Household-level cross-sectional surveys, including parasitological and entomological sampling, will be conducted on a rolling, 2-monthly schedule to measure outcomes over two years (2016 to 2018). Coverage of LSM and HI will also be assessed throughout the trial area. Combining LSM and/or HI together with the interventions currently implemented by the Malawi National Malaria Control Programme is anticipated to reduce malaria transmission below the level reached by current interventions alone. Implementation of LSM and HI through a community-based approach provides an opportunity for optimum adaptation to the local ecological and social setting, and enhances the potential for sustainability. Registered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493.
Combination of indoor residual spraying with long-lasting insecticide-treated nets for malaria control in Zambezia, Mozambique: a cluster randomised trial and cost-effectiveness study protocol

PubMed Central

Alonso, Sergi; Zulliger, Rose; Wagman, Joe; Saifodine, Abuchahama; Candrinho, Baltazar; Macete, Eusébio; Brew, Joe; Fornadel, Christen; Kassim, Hidayat; Loch, Lourdes; Sacoor, Charfudin; Varela, Kenyssony; Carty, Cara L; Robertson, Molly; Saute, Francisco

2018-01-01

Background Most of the reduction in malaria prevalence seen in Africa since 2000 has been attributed to vector control interventions. Yet increases in the distribution and intensity of insecticide resistance and higher costs of newer insecticides pose a challenge to sustaining these gains. Thus, endemic countries face challenging decisions regarding the choice of vector control interventions. Methods A cluster randomised trial is being carried out in Mopeia District in the Zambezia Province of Mozambique, where malaria prevalence in children under 5 is high (68% in 2015), despite continuous and campaign distribution of long-lasting insecticide-treated nets (LLINs). Study arm 1 will continue to use the standard, LLIN-based National Malaria Control Programme vector control strategy (LLINs only), while study arm 2 will receive indoor residual spraying (IRS) once a year for 2 years with a microencapsulated formulation of pirimiphos-methyl (Actellic 300 CS), in addition to the standard LLIN strategy (LLINs+IRS). Prior to the 2016 IRS implementation (the first of two IRS campaigns in this study), 146 clusters were defined and stratified per number of households. Clusters were then randomised 1:1 into the two study arms. The public health impact and cost-effectiveness of IRS intervention will be evaluated over 2 years using multiple methods: (1) monthly active malaria case detection in a cohort of 1548 total children aged 6–59 months; (2) enhanced passive surveillance at health facilities and with community health workers; (3) annual cross-sectional surveys; and (4) entomological surveillance. Prospective microcosting of the intervention and provider and societal costs will be conducted. Insecticide resistance status pattern and changes in local Anopheline populations will be included as important supportive outcomes. Discussion By evaluating the public health impact and cost-effectiveness of IRS with a non-pyrethroid insecticide in a high-transmission setting with high LLIN ownership, it is expected that this study will provide programmatic and policy-relevant data to guide national and global vector control strategies. Trial registration number NCT02910934. PMID:29564161
Vitamin K supplementation for cystic fibrosis.

PubMed

Jagannath, Vanitha A; Fedorowicz, Zbys; Thaker, Vidhu; Chang, Anne B

2011-01-19

Cystic fibrosis is a genetic disorder which can lead to multiorgan dysfunction. Malabsorption of fat and fat-soluble vitamins (A, D, E, K) may occur and can cause subclinical deficiencies of some of these vitamins. Vitamin K is known to play an important role in both blood coagulation and bone formation. Supplementation with vitamin K appears to be one way of addressing the deficiency, but there is very limited agreement on the appropriate dose and frequency of use of these supplements. To assess the effects of vitamin K supplementation in people with cystic fibrosis and to determine the optimal dose and route of administration of vitamin K for both routine and therapeutic use. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Most recent search: 15 April 2010. Randomised and quasi-randomised controlled trials of all preparations of vitamin K used as a supplement compared to either no supplementation (or placebo) at any dose or route and for any duration, in children or adults diagnosed with cystic fibrosis (by sweat test or genetic testing). Two authors independently screened papers, extracted trial details and assessed their risk of bias. Two trials (total of 32 participants) were included in the review and were assessed as having a moderate risk of bias. One was a dose-ranging parallel group trial; and the other had a cross-over design, but no separate data were reported for the first intervention period. Neither of the trials addressed any of the primary outcomes (coagulation, bone formation and quality of life). Both trials reported the restoration of serum vitamin K and undercarboxylated osteocalcin levels to the normal range after one month of daily supplementation with 1 mg of vitamin K. Evidence from randomised controlled trials on the benefits of routine vitamin K supplementation for people with CF is currently weak and limited to two small trials of short duration. However, no harm was found and until further evidence is available, the present recommendations should be adhered to.

Vitamin K supplementation for cystic fibrosis.

PubMed

Jagannath, Vanitha A; Fedorowicz, Zbys; Thaker, Vidhu; Chang, Anne B

2013-04-30

Cystic fibrosis is a genetic disorder which can lead to multiorgan dysfunction. Malabsorption of fat and fat-soluble vitamins (A, D, E, K) may occur and can cause subclinical deficiencies of some of these vitamins. Vitamin K is known to play an important role in both blood coagulation and bone formation. Supplementation with vitamin K appears to be one way of addressing the deficiency, but there is very limited agreement on the appropriate dose and frequency of use of these supplements. To assess the effects of vitamin K supplementation in people with cystic fibrosis and to determine the optimal dose and route of administration of vitamin K for both routine and therapeutic use. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Most recent search: 11 October 2012. Randomised and quasi-randomised controlled trials of all preparations of vitamin K used as a supplement compared to either no supplementation (or placebo) at any dose or route and for any duration, in children or adults diagnosed with cystic fibrosis (by sweat test or genetic testing). Two authors independently screened papers, extracted trial details and assessed their risk of bias. Two trials (total of 32 participants) were included in the review and were assessed as having a moderate risk of bias. One was a dose-ranging parallel group trial; and the other had a cross-over design, but no separate data were reported for the first intervention period. Neither of the trials addressed any of the primary outcomes (coagulation, bone formation and quality of life). Both trials reported the restoration of serum vitamin K and undercarboxylated osteocalcin levels to the normal range after one month of daily supplementation with 1 mg of vitamin K. Evidence from randomised controlled trials on the benefits of routine vitamin K supplementation for people with CF is currently weak and limited to two small trials of short duration. However, no harm was found and until further evidence is available, the present recommendations should be adhered to.
Combination of indoor residual spraying with long-lasting insecticide-treated nets for malaria control in Zambezia, Mozambique: a cluster randomised trial and cost-effectiveness study protocol.

PubMed

Chaccour, Carlos J; Alonso, Sergi; Zulliger, Rose; Wagman, Joe; Saifodine, Abuchahama; Candrinho, Baltazar; Macete, Eusébio; Brew, Joe; Fornadel, Christen; Kassim, Hidayat; Loch, Lourdes; Sacoor, Charfudin; Varela, Kenyssony; Carty, Cara L; Robertson, Molly; Saute, Francisco

2018-01-01

Most of the reduction in malaria prevalence seen in Africa since 2000 has been attributed to vector control interventions. Yet increases in the distribution and intensity of insecticide resistance and higher costs of newer insecticides pose a challenge to sustaining these gains. Thus, endemic countries face challenging decisions regarding the choice of vector control interventions. A cluster randomised trial is being carried out in Mopeia District in the Zambezia Province of Mozambique, where malaria prevalence in children under 5 is high (68% in 2015), despite continuous and campaign distribution of long-lasting insecticide-treated nets (LLINs). Study arm 1 will continue to use the standard, LLIN-based National Malaria Control Programme vector control strategy (LLINs only), while study arm 2 will receive indoor residual spraying (IRS) once a year for 2 years with a microencapsulated formulation of pirimiphos-methyl (Actellic 300 CS), in addition to the standard LLIN strategy (LLINs+IRS). Prior to the 2016 IRS implementation (the first of two IRS campaigns in this study), 146 clusters were defined and stratified per number of households. Clusters were then randomised 1:1 into the two study arms. The public health impact and cost-effectiveness of IRS intervention will be evaluated over 2 years using multiple methods: (1) monthly active malaria case detection in a cohort of 1548 total children aged 6-59 months; (2) enhanced passive surveillance at health facilities and with community health workers; (3) annual cross-sectional surveys; and (4) entomological surveillance. Prospective microcosting of the intervention and provider and societal costs will be conducted. Insecticide resistance status pattern and changes in local Anopheline populations will be included as important supportive outcomes. By evaluating the public health impact and cost-effectiveness of IRS with a non-pyrethroid insecticide in a high-transmission setting with high LLIN ownership, it is expected that this study will provide programmatic and policy-relevant data to guide national and global vector control strategies. NCT02910934.
Hydrodynamic boundary condition of water on hydrophobic surfaces.

PubMed

Schaeffel, David; Yordanov, Stoyan; Schmelzeisen, Marcus; Yamamoto, Tetsuya; Kappl, Michael; Schmitz, Roman; Dünweg, Burkhard; Butt, Hans-Jürgen; Koynov, Kaloian

2013-05-01

By combining total internal reflection fluorescence cross-correlation spectroscopy with Brownian dynamics simulations, we were able to measure the hydrodynamic boundary condition of water flowing over a smooth solid surface with exceptional accuracy. We analyzed the flow of aqueous electrolytes over glass coated with a layer of poly(dimethylsiloxane) (advancing contact angle Θ = 108°) or perfluorosilane (Θ = 113°). Within an error of better than 10 nm the slip length was indistinguishable from zero on all surfaces.
Using the AIDA--www.2aida.org--diabetes simulator. Part 2: recommended training requirements for health-carers planning to teach with the software.

PubMed

Lehmann, Eldon D; Tatti, Patrizio

2002-01-01

The purpose of this article is to document some recommended training requirements for health-carers planning to teach using the AIDA interactive educational diabetes simulator. AIDA is a diabetes computer program that permits the interactive simulation of plasma insulin and blood glucose profiles for teaching, demonstration, and self-learning purposes. It has been made freely available, without charge, on the Internet as a noncommercial contribution to continuing diabetes education. Since its launch in 1996 over 200,000 visits have been logged at the AIDA Website--www.2aida.org--and over 40,000 copies of the AIDA program have been downloaded free-of-charge. This report describes various training requirements that are recommended for health-care professionals who are interested in teaching with the software. Intended goals of this article are to answer possible questions from teachers using the program, highlight some minimum recommended training requirements for the software, suggest some "hints and tips" for teaching ideas, explain the importance of performing more studies/trials with the program, overview randomised controlled trial usage of the software, and highlight the importance of obtaining feedback from lesson participants. The recommendations seem to be straightforward and should help in formalising training with the program, as well as in the development of a network of teachers "accredited" to give lessons using the software. This report, together with the previous article (Part 1, Diabetes Technol Ther 2002;4:401-414), highlights the utility of providing guidelines and suggesting recommended training requirements for health-carers planning to make use of educational medical/diabetes software.
Micro Blowing Simulations Using a Coupled Finite-Volume Lattice-Boltzman n L ES Approach

NASA Technical Reports Server (NTRS)

Menon, S.; Feiz, H.

1990-01-01

Three dimensional large-eddy simulations (LES) of single and multiple jet-in-cross-flow (JICF) are conducted using the 19-bit Lattice Boltzmann Equation (LBE) method coupled with a conventional finite-volume (FV) scheme. In this coupled LBE-FV approach, the LBE-LES is employed to simulate the flow inside the jet nozzles while the FV-LES is used to simulate the crossflow. The key application area is the use of this technique is to study the micro blowing technique (MBT) for drag control similar to the recent experiments at NASA/GRC. It is necessary to resolve the flow inside the micro-blowing and suction holes with high resolution without being restricted by the FV time-step restriction. The coupled LBE-FV-LES approach achieves this objectives in a computationally efficient manner. A single jet in crossflow case is used for validation purpose and the results are compared with experimental data and full LBE-LES simulation. Good agreement with data is obtained. Subsequently, MBT over a flat plate with porosity of 25% is simulated using 9 jets in a compressible cross flow at a Mach number of 0.4. It is shown that MBT suppresses the near-wall vortices and reduces the skin friction by up to 50 percent. This is in good agreement with experimental data.
Short structured general mental health in service training programme in Kenya improves patient health and social outcomes but not detection of mental health problems - a pragmatic cluster randomised controlled trial

PubMed Central

2013-01-01

Trial design A pragmatic cluster randomised controlled trial. Methods Participants: Clusters were primary health care clinics on the Ministry of Health list. Clients were eligible if they were aged 18 and over. Interventions: Two members of staff from each intervention clinic received the training programme. Clients in both intervention and control clinics subsequently received normal routine care from their health workers. Objective: To examine the impact of a mental health inservice training on routine detection of mental disorder in the clinics and on client outcomes. Outcomes: The primary outcome was the rate of accurate routine clinic detection of mental disorder and the secondary outcome was client recovery over a twelve week follow up period. Randomisation: clinics were randomised to intervention and control groups using a table of random numbers. Blinding: researchers and clients were blind to group assignment. Results Numbers randomised: 49 and 50 clinics were assigned to intervention and control groups respectively. 12 GHQ positive clients per clinic were identified for follow up. Numbers analysed: 468 and 478 clients were followed up for three months in intervention and control groups respectively. Outcome: At twelve weeks after training of the intervention group, the rate of accurate routine clinic detection of mental disorder was greater than 0 in 5% versus 0% of the intervention and control groups respectively, in both the intention to treat analysis (p = 0.50) and the per protocol analysis (p =0.50). Standardised effect sizes for client improvement were 0.34 (95% CI = (0.01,0.68)) for the General Health Questionnaire, 0.39 ((95% CI = (0.22, 0.61)) for the EQ and 0.49 (95% CI = (0.11,0.87)) for WHODAS (using ITT analysis); and 0.43 (95% CI = (0.09,0.76)) for the GHQ, 0.44 (95% CI = (0.22,0.65)) for the EQ and 0.58 (95% CI = (0.18,0.97)) for WHODAS (using per protocol analysis). Harms: None identified. Conclusion The training programme did not result in significantly improved recorded diagnostic rates of mental disorders in the routine clinic consultation register, but did have significant effects on patient outcomes in routine clinical practice. Trial registration International Standard Randomised Controlled Trial Number Register ISRCTN53515024. PMID:24188964
A systematic review of cluster randomised trials in residential facilities for older people suggests how to improve quality.

PubMed

Diaz-Ordaz, Karla; Froud, Robert; Sheehan, Bart; Eldridge, Sandra

2013-10-22

Previous reviews of cluster randomised trials have been critical of the quality of the trials reviewed, but none has explored determinants of the quality of these trials in a specific field over an extended period of time. Recent work suggests that correct conduct and reporting of these trials may require more than published guidelines. In this review, our aim was to assess the quality of cluster randomised trials conducted in residential facilities for older people, and to determine whether (1) statistician involvement in the trial and (2) strength of journal endorsement of the Consolidated Standards of Reporting Trials (CONSORT) statement influence quality. We systematically identified trials randomising residential facilities for older people, or parts thereof, without language restrictions, up to the end of 2010, using National Library of Medicine (Medline) via PubMed and hand-searching. We based quality assessment criteria largely on the extended CONSORT statement for cluster randomised trials. We assessed statistician involvement based on statistician co-authorship, and strength of journal endorsement of the CONSORT statement from journal websites. 73 trials met our inclusion criteria. Of these, 20 (27%) reported accounting for clustering in sample size calculations and 54 (74%) in the analyses. In 29 trials (40%), methods used to identify/recruit participants were judged by us to have potentially caused bias or reporting was unclear to reach a conclusion. Some elements of quality improved over time but this appeared not to be related to the publication of the extended CONSORT statement for these trials. Trials with statistician/epidemiologist co-authors were more likely to account for clustering in sample size calculations (unadjusted odds ratio 5.4, 95% confidence interval 1.1 to 26.0) and analyses (unadjusted OR 3.2, 1.2 to 8.5). Journal endorsement of the CONSORT statement was not associated with trial quality. Despite international attempts to improve methods in cluster randomised trials, important quality limitations remain amongst these trials in residential facilities. Statistician involvement on trial teams may be more effective in promoting quality than further journal endorsement of the CONSORT statement. Funding bodies and journals should promote statistician involvement and co-authorship in addition to adherence to CONSORT guidelines.
Contact area of rough spheres: Large scale simulations and simple scaling laws

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pastewka, Lars, E-mail: lars.pastewka@kit.edu; Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218; Robbins, Mark O., E-mail: mr@pha.jhu.edu

2016-05-30

We use molecular simulations to study the nonadhesive and adhesive atomic-scale contact of rough spheres with radii ranging from nanometers to micrometers over more than ten orders of magnitude in applied normal load. At the lowest loads, the interfacial mechanics is governed by the contact mechanics of the first asperity that touches. The dependence of contact area on normal force becomes linear at intermediate loads and crosses over to Hertzian at the largest loads. By combining theories for the limiting cases of nominally flat rough surfaces and smooth spheres, we provide parameter-free analytical expressions for contact area over the wholemore » range of loads. Our results establish a range of validity for common approximations that neglect curvature or roughness in modeling objects on scales from atomic force microscope tips to ball bearings.« less
Clinical trial design and dissemination: comprehensive analysis of clinicaltrials.gov and PubMed data since 2005

PubMed Central

Davies, Mark; Hingorani, Aroon D; Hunter, Jackie

2018-01-01

Abstract Objective To investigate the distribution, design characteristics, and dissemination of clinical trials by funding organisation and medical specialty. Design Cross sectional descriptive analysis. Data sources Trial protocol information from clinicaltrials.gov, metadata of journal articles in which trial results were published (PubMed), and quality metrics of associated journals from SCImago Journal and Country Rank database. Selection criteria All 45 620 clinical trials evaluating small molecule therapeutics, biological drugs, adjuvants, and vaccines, completed after January 2006 and before July 2015, including randomised controlled trials and non-randomised studies across all clinical phases. Results Industry was more likely than non-profit funders to fund large international randomised controlled trials, although methodological differences have been decreasing with time. Among 27 835 completed efficacy trials (phase II-IV), 15 084 (54.2%) had disclosed their findings publicly. Industry was more likely than non-profit trial funders to disseminate trial results (59.3% (10 444/17 627) v 45.3% (4555/10 066)), and large drug companies had higher disclosure rates than small ones (66.7% (7681/11 508) v 45.2% (2763/6119)). Trials funded by the National Institutes of Health (NIH) were disseminated more often than those of other non-profit institutions (60.0% (1451/2417) v 40.6% (3104/7649)). Results of studies funded by large drug companies and NIH were more likely to appear on clinicaltrials.gov than were those from non-profit funders, which were published mainly as journal articles. Trials reporting the use of randomisation were more likely than non-randomised studies to be published in a journal article (6895/19 711 (34.9%) v 1408/7748 (18.2%)), and journal publication rates varied across disease areas, ranging from 42% for autoimmune diseases to 20% for oncology. Conclusions Trial design and dissemination of results vary substantially depending on the type and size of funding institution as well as the disease area under study. PMID:29875212
Dietary assessment among women with overweight and obesity in early postpartum.

PubMed

Huseinovic, E; Winkvist, A; Bertz, F; Hellebö Johansson, E; Brekke, H K

2016-08-01

The present study aimed to assess dietary intake and evaluate the degree of agreement of group-level dietary intake as measured by 24-h recall against a 4-day diet record among postpartum women with overweight and obesity. A cross-sectional study was conducted of 110 Swedish women with a body mass index of ≥27 kg m(-2) at 6-15 weeks postpartum who were recruited to a weight loss trial and randomised to diet intervention or control. One 24-h recall was conducted among all women prior to randomisation. In addition, women subsequently randomised to diet intervention also conducted a 4-day diet record before receiving dietary treatment (n = 54). Paired tests were used to evaluate agreement of group-level dietary intake as measured by 24-h recall against 4-day diet record among women randomised to diet intervention. Women reported a median (25th and 75th percentiles) energy intake of 9.1 (6.9, 11.7) MJ day(-1) and an intake of fibre, vitamin D, folate and iron below the recommended intake as assessed by 24-h recall prior to randomisation (n = 110). Group-level median intakes of energy (9.9 versus 10.0 MJ day(-1) ), fibre (21.9 versus 21.3 g day(-1) ), vitamin D (4.8 versus 6.5 μg day(-1) ), folate (296 versus 287 μg day(-1) ), iron (11.0 versus 11.3 mg day(-1) ) and calcium (915 versus 968 mg day(-1) ) did not differ significantly between the methods; however, the record captured a higher energy-adjusted intake of fat, saturated fat and alcohol, as well as a lower intake of carbohydrates, compared to the recall (n = 54). We found no difference in group-level estimates of energy or micronutrients between the recall and the record; however, there were some differences for macronutrients. © 2015 The British Dietetic Association Ltd.
Systematic Review of Voluntary Participation in Simulation-Based Laparoscopic Skills Training: Motivators and Barriers for Surgical Trainee Attendance.

PubMed

Gostlow, Hannah; Marlow, Nicholas; Babidge, Wendy; Maddern, Guy

To examine and report on evidence relating to surgical trainees' voluntary participation in simulation-based laparoscopic skills training. Specifically, the underlying motivators, enablers, and barriers faced by surgical trainees with regard to attending training sessions on a regular basis. A systematic search of the literature (PubMed; CINAHL; EMBASE; Cochrane Collaboration) was conducted between May and July 2015. Studies were included on whether they reported on surgical trainee attendance at voluntary, simulation-based laparoscopic skills training sessions, in addition to qualitative data regarding participant's perceived barriers and motivators influencing their decision to attend such training. Factors affecting a trainee's motivation were categorized as either intrinsic (internal) or extrinsic (external). Two randomised control trials and 7 case series' met our inclusion criteria. Included studies were small and generally poor quality. Overall, voluntary simulation-based laparoscopic skills training was not well attended. Intrinsic motivators included clearly defined personal performance goals and relevance to clinical practice. Extrinsic motivators included clinical responsibilities and available free time, simulator location close to clinical training, and setting obligatory assessments or mandated training sessions. The effect of each of these factors was variable, and largely dependent on the individual trainee. The greatest reported barrier to attending voluntary training was the lack of available free time. Although data quality is limited, it can be seen that providing unrestricted access to simulator equipment is not effective in motivating surgical trainees to voluntarily participate in simulation-based laparoscopic skills training. To successfully encourage participation, consideration needs to be given to the factors influencing motivation to attend training. Further research, including better designed randomised control trials and large-scale surveys, is required to provide more definitive answers to the degree in which various incentives influence trainees' motivations and actual attendance rates. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Positive impact of crisis resource management training on no-flow time and team member verbalisations during simulated cardiopulmonary resuscitation: a randomised controlled trial.

PubMed

Fernandez Castelao, Ezequiel; Russo, Sebastian G; Cremer, Stephan; Strack, Micha; Kaminski, Lea; Eich, Christoph; Timmermann, Arnd; Boos, Margarete

2011-10-01

To evaluate the impact of video-based interactive crisis resource management (CRM) training on no-flow time (NFT) and on proportions of team member verbalisations (TMV) during simulated cardiopulmonary resuscitation (CPR). Further, to investigate the link between team leader verbalisation accuracy and NFT. The randomised controlled study was embedded in the obligatory advanced life support (ALS) course for final-year medical students. Students (176; 25.35±1.03 years, 63% female) were alphabetically assigned to 44 four-person teams that were then randomly (computer-generated) assigned to either CRM intervention (n=26), receiving interactive video-based CRM-training, or to control intervention (n=18), receiving an additional ALS-training. Primary outcomes were NFT and proportions of TMV, which were subdivided into eight categories: four team leader verbalisations (TLV) with different accuracy levels and four follower verbalisation categories (FV). Measurements were made of all groups administering simulated adult CPR. NFT rates were significantly lower in the CRM-training group (31.4±6.1% vs. 36.3±6.6%, p=0.014). Proportions of all TLV categories were higher in the CRM-training group (p<0.001). Differences in FV were only found for one category (unsolicited information) (p=0.012). The highest correlation with NFT was found for high accuracy TLV (direct orders) (p=0.06). The inclusion of CRM training in undergraduate medical education reduces NFT in simulated CPR and improves TLV proportions during simulated CPR. Further research will test how these results translate into clinical performance and patient outcome. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Efficacy of simulation-based trauma team training of non-technical skills. A systematic review.

PubMed

Gjeraa, K; Møller, T P; Østergaard, D

2014-08-01

Trauma resuscitation is a complex situation, and most organisations have multi-professional trauma teams. Non-technical skills are challenged during trauma resuscitation, and they play an important role in the prevention of critical incidents. Simulation-based training of these is recommended. Our research question was: Does simulation-based trauma team training of non-technical skills have effect on reaction, learning, behaviour or patient outcome? The authors searched PubMed, EMBASE and the Cochrane Library and found 13 studies eligible for analysis. We described and compared the educational interventions and the evaluations of effect according to the four Kirkpatrick levels: reaction, learning (knowledge, skills, attitudes), behaviour (in a clinical setting) and patient outcome. No studies were randomised, controlled and blinded, resulting in a moderate to high risk of bias. The multi-professional trauma teams had positive reactions to simulation-based training of non-technical skills. Knowledge and skills improved in all studies evaluating the effect on learning. Three studies found improvements in team performance (behaviour) in the clinical setting. One of these found difficulties in maintaining these skills. Two studies evaluated on patient outcome, of which none showed improvements in mortality, complication rate or duration of hospitalisation. A significant effect on learning was found after simulation-based training of the multi-professional trauma team in non-technical skills. Three studies demonstrated significantly increased clinical team performance. No effect on patient outcome was found. All studies had a moderate to high risk of bias. More comprehensive randomised studies are needed to evaluate the effect on patient outcome. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
Development of an in silico stochastic 4D model of tumor growth with angiogenesis.

PubMed

Forster, Jake C; Douglass, Michael J J; Harriss-Phillips, Wendy M; Bezak, Eva

2017-04-01

A stochastic computer model of tumour growth with spatial and temporal components that includes tumour angiogenesis was developed. In the current work it was used to simulate head and neck tumour growth. The model also provides the foundation for a 4D cellular radiotherapy simulation tool. The model, developed in Matlab, contains cell positions randomised in 3D space without overlap. Blood vessels are represented by strings of blood vessel units which branch outwards to achieve the desired tumour relative vascular volume. Hypoxic cells have an increased cell cycle time and become quiescent at oxygen tensions less than 1 mmHg. Necrotic cells are resorbed. A hierarchy of stem cells, transit cells and differentiated cells is considered along with differentiated cell loss. Model parameters include the relative vascular volume (2-10%), blood oxygenation (20-100 mmHg), distance from vessels to the onset of necrosis (80-300 μm) and probability for stem cells to undergo symmetric division (2%). Simulations were performed to observe the effects of hypoxia on tumour growth rate for head and neck cancers. Simulations were run on a supercomputer with eligible parts running in parallel on 12 cores. Using biologically plausible model parameters for head and neck cancers, the tumour volume doubling time varied from 45 ± 5 days (n = 3) for well oxygenated tumours to 87 ± 5 days (n = 3) for severely hypoxic tumours. The main achievements of the current model were randomised cell positions and the connected vasculature structure between the cells. These developments will also be beneficial when irradiating the simulated tumours using Monte Carlo track structure methods. © 2017 American Association of Physicists in Medicine.
Investigation of Altitude Starting and Acceleration Characteristics of J47 Turbojet Engine

NASA Technical Reports Server (NTRS)

Golladay, Richard L; Bloomer, Harry E

1951-01-01

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.
Lay public's understanding of equipoise and randomisation in randomised controlled trials.

PubMed

Robinson, E J; Kerr, C E P; Stevens, A J; Lilford, R J; Braunholtz, D A; Edwards, S J; Beck, S R; Rowley, M G

2005-03-01

To research the lay public's understanding of equipoise and randomisation in randomised controlled trials (RCTs) and to look at why information on this may not be not taken in or remembered, as well as the effects of providing information designed to overcome barriers. Investigations were informed by an update of systematic review on patients' understanding of consent information in clinical trials, and by relevant theory and evidence from experimental psychology. Nine investigations were conducted with nine participants. Access (return to education), leisure and vocational courses at Further Education Colleges in the Midlands, UK. Healthy adults with a wide range of educational backgrounds and ages. Participants read hypothetical scenarios and wrote brief answers to subsequent questions. Sub-samples of participants were interviewed individually to elaborate on their written answers. Participants' background assumptions concerning equipoise and randomisation were examined and ways of helping participants recognise the scientific benefits of randomisation were explored. Judgments on allocation methods; treatment preferences; the acceptability of random allocation; whether or not individual doctors could be completely unsure about the best treatment; whether or not doctors should reveal treatment preferences under conditions of collective equipoise; and how sure experts would be about the best treatment following random allocation vs doctor/patient choice. Assessments of understanding hypothetical trial information. Recent literature continues to report trial participants' failure to understand or remember information about randomisation and equipoise, despite the provision of clear and readable trial information leaflets. In current best practice, written trial information describes what will happen without offering accessible explanations. As a consequence, patients may create their own incorrect interpretations and consent or refusal may be inadequately informed. In six investigations, most participants identified which methods of allocation were random, but judged the random allocation methods to be unacceptable in a trial context; the mere description of a treatment as new was insufficient to engender a preference for it over a standard treatment; around half of the participants denied that a doctor could be completely unsure about the best treatment. A majority of participants judged it unacceptable for a doctor to suggest letting chance decide when uncertain of the best treatment, and, in the absence of a justification for random allocation, participants did not recognise scientific benefits of random allocation over normal treatment allocation methods. The pattern of results across three intervention studies suggests that merely supplementing written trial information with an explanation is unlikely to be helpful. However, when people manage to focus on the trial's aim of increasing knowledge (as opposed to making treatment decisions about individuals), and process an explanation actively, they may be helped to understand the scientific reasons for random allocation. This research was not carried out in real healthcare settings. However, participants who could correctly identify random allocation methods, yet judged random allocation unacceptable, doubted the possibility of individual equipoise and saw no scientific benefits of random allocation over doctor/patient choice, are unlikely to draw upon contrasting views if invited to enter a real clinical trial. This suggests that many potential trial participants may have difficulty understanding and remembering trial information that conforms to current best practice in its descriptions of randomisation and equipoise. Given the extent of the disparity between the assumptions underlying trial design and the assumptions held by the lay public, the solution is unlikely to be simple. Nevertheless, the results suggest that including an accessible explanation of the scientific benefits of randomisation may be beneficial provided potential participants are also enabled to reflect on the trial's aim of advancing knowledge, and to think actively about the information presented. Further areas for consideration include: the identification of effective combinations of written and oral information; helping participants to reflect on the aim of advancing knowledge; and an evidence-based approach to leaflet construction.
Adolescents’ use of purpose built shade in secondary schools: cluster randomised controlled trial

PubMed Central

White, Vanessa; Wakefield, Melanie A; Jamsen, Kris M; White, Victoria; Livingston, Patricia M; English, Dallas R; Simpson, Julie A

2009-01-01

Objective To examine whether students use or avoid newly shaded areas created by shade sails installed at schools. Design Cluster randomised controlled trial with secondary schools as the unit of randomisation. Setting 51 secondary schools with limited available shade, in Australia, assessed over two spring and summer terms. Participants Students outside at lunch times. Intervention Purpose built shade sails were installed in winter 2005 at full sun study sites to increase available shade for students in the school grounds. Main outcome measure Mean number of students using the primary study sites during weekly observations at lunch time. Results Over the study period the mean change in students using the primary study site from pre-test to post-test was 2.63 (95% confidence interval 0.87 to 4.39) students in intervention schools and −0.03 (−1.16 to 1.09) students in control schools. The difference in mean change between groups was 2.67 (0.65 to 4.68) students (P=0.011). Conclusions Students used rather than avoided newly shaded areas provided by purpose built shade sails at secondary schools in this trial, suggesting a practical means of reducing adolescents’ exposure to ultraviolet radiation. Trial registration Exempt. PMID:19223344
Increasing walking among older people: A test of behaviour change techniques using factorial randomised N-of-1 trials

PubMed Central

Nyman, Samuel R.; Goodwin, Kelly; Kwasnicka, Dominika; Callaway, Andrew

2016-01-01

Objective: Evaluations of techniques to promote physical activity usually adopt a randomised controlled trial (RCT). Such designs inform how a technique performs on average but cannot be used for treatment of individuals. Our objective was to conduct the first N-of-1 RCTs of behaviour change techniques with older people and test the effectiveness of the techniques for increasing walking within individuals. Design: Eight adults aged 60–87 were randomised to a 2 (goal-setting vs. active control) × 2 (self-monitoring vs. active control) factorial RCT over 62 days. The time series data were analysed for each single case using linear regressions. Main outcome measures: Walking was objectively measured using pedometers. Results: Compared to control days, goal-setting increased walking in 4 out of 8 individuals and self-monitoring increased walking in 7 out of 8 individuals. While the probability for self-monitoring to be effective in 7 out of 8 participants was beyond chance (p = .03), no intervention effect was significant for individual participants. Two participants had a significant but small linear decrease in walking over time. Conclusion: We demonstrate the utility of N-of-1 trials for advancing scientific enquiry of behaviour change and in practice for increasing older people’s physical activity. PMID:26387689
Coupled simulations and comparison with multi-lidar measurements of the wind flow over a double-ridge

NASA Astrophysics Data System (ADS)

Veiga Rodrigues, C.; Palma, JMLM; Vasiljević, N.; Courtney, M.; Mann, J.

2016-09-01

The wind flow over a double-ridge site has been numerically simulated with a nested model- chain coupling, down to horizontal resolutions of 40 m. The results were compared with field measurements attained using a triple-lidar instrument, the long-range WindScanner system, which allowed measurements up to 500 m height and the mapping of the wind speed onto a two-dimensional transect crossing the valley. The site, known as Serra do Perdigão, is located in central Portugal and consists of two parallel ridges 1.4 km apart with height differences of 200 m in between, being characterized by rough terrain and forested areas. The analysis was restricted to June 10th 2015, for which measurements and simulations both predicted gravity wave activity, the later showing formation of rotors in the lee of both ridges and some events of wave breaking above the ridge top.
Attitude control/momentum management of the Space Station Freedom for large angle torque-equilibrium-attitude configurations

NASA Technical Reports Server (NTRS)

Parlos, Alexander G.; Sunkel, John W.

1990-01-01

An attitude-control and momentum-management (ACMM) system for the Space Station in a large-angle torque-equilibrium-attitude (TEA) configuration is developed analytically and demonstrated by means of numerical simulations. The equations of motion for a rigid-body Space Station model are outlined; linearized equations for an arbitrary TEA (resulting from misalignment of control and body axes) are derived; the general requirements for an ACMM are summarized; and a pole-placement linear-quadratic regulator solution based on scheduled gains is proposed. Results are presented in graphs for (1) simulations based on configuration MB3 (showing the importance of accounting for the cross-inertia terms in the TEA estimate) and (2) simulations of a stepwise change from configuration MB3 to the 'assembly complete' stage over 130 orbits (indicating that the present ACCM scheme maintains sufficient control over slowly varying Space Station dynamics).

Effects of emotion recognition training on mood among individuals with high levels of depressive symptoms: study protocol for a randomised controlled trial

PubMed Central

2013-01-01

Background We have developed a new paradigm that targets the recognition of facial expression of emotions. Here we report the protocol of a randomised controlled trial of the effects of emotion recognition training on mood in a sample of individuals with depressive symptoms over a 6-week follow-up period. Methods/Design We will recruit 190 adults from the general population who report high levels of depressive symptoms (defined as a score ≥ 14 on the Beck Depression Inventory-II). Participants will attend a screening session and will be randomised to intervention or control procedures, repeated five times over consecutive days (Monday to Friday). A follow-up session will take place at end-of -treatment, 2-weeks and 6-weeks after training. Our primary study outcome will be depressive symptoms, Beck Depression Inventory- II (rated over the past two weeks). Our secondary outcomes are: depressive symptoms, Hamilton Rating Scale for Depression; anxiety symptoms, Beck Anxiety Inventory (rated over the past month); positive affect, Positive and Negative Affect Schedule (rated as ‘how you feel right now’); negative affect, Positive and Negative Affect Schedule (rated as ‘how you feel right now’); emotion sensitivity, Emotion Recognition Task (test phase); approach motivation and persistence, the Fishing Game; and depressive interpretation bias, Scrambled Sentences Test. Discussion This study is of a novel cognitive bias modification technique that targets biases in emotional processing characteristic of depression, and can be delivered automatically via computer, Internet or Smartphone. It therefore has potential to be a valuable cost-effective adjunctive treatment for depression which may be used together with more traditional psychotherapy, cognitive-behavioural therapy and pharmacotherapy. Trial registration Current Controlled Trials: ISRCTN17767674 PMID:23725208
Effects of emotion recognition training on mood among individuals with high levels of depressive symptoms: study protocol for a randomised controlled trial.

PubMed

Adams, Sally; Penton-Voak, Ian S; Harmer, Catherine J; Holmes, Emily A; Munafò, Marcus R

2013-06-01

We have developed a new paradigm that targets the recognition of facial expression of emotions. Here we report the protocol of a randomised controlled trial of the effects of emotion recognition training on mood in a sample of individuals with depressive symptoms over a 6-week follow-up period. We will recruit 190 adults from the general population who report high levels of depressive symptoms (defined as a score ≥ 14 on the Beck Depression Inventory-II). Participants will attend a screening session and will be randomised to intervention or control procedures, repeated five times over consecutive days (Monday to Friday). A follow-up session will take place at end-of -treatment, 2-weeks and 6-weeks after training. Our primary study outcome will be depressive symptoms, Beck Depression Inventory- II (rated over the past two weeks). Our secondary outcomes are: depressive symptoms, Hamilton Rating Scale for Depression; anxiety symptoms, Beck Anxiety Inventory (rated over the past month); positive affect, Positive and Negative Affect Schedule (rated as 'how you feel right now'); negative affect, Positive and Negative Affect Schedule (rated as 'how you feel right now'); emotion sensitivity, Emotion Recognition Task (test phase); approach motivation and persistence, the Fishing Game; and depressive interpretation bias, Scrambled Sentences Test. This study is of a novel cognitive bias modification technique that targets biases in emotional processing characteristic of depression, and can be delivered automatically via computer, Internet or Smartphone. It therefore has potential to be a valuable cost-effective adjunctive treatment for depression which may be used together with more traditional psychotherapy, cognitive-behavioural therapy and pharmacotherapy. Current Controlled Trials: ISRCTN17767674.
Evaluation of a theory-informed implementation intervention for the management of acute low back pain in general medical practice: the IMPLEMENT cluster randomised trial.

PubMed

French, Simon D; McKenzie, Joanne E; O'Connor, Denise A; Grimshaw, Jeremy M; Mortimer, Duncan; Francis, Jill J; Michie, Susan; Spike, Neil; Schattner, Peter; Kent, Peter; Buchbinder, Rachelle; Page, Matthew J; Green, Sally E

2013-01-01

This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Australian New Zealand Clinical Trials Registry ACTRN012606000098538.
Evaluation of a Theory-Informed Implementation Intervention for the Management of Acute Low Back Pain in General Medical Practice: The IMPLEMENT Cluster Randomised Trial

PubMed Central

French, Simon D.; McKenzie, Joanne E.; O'Connor, Denise A.; Grimshaw, Jeremy M.; Mortimer, Duncan; Francis, Jill J.; Michie, Susan; Spike, Neil; Schattner, Peter; Kent, Peter; Buchbinder, Rachelle; Page, Matthew J.; Green, Sally E.

2013-01-01

Introduction This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. Methods General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. Results 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. Conclusions The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN012606000098538 PMID:23785427
Scattering of a cross-polarized linear wave by a soliton at an optical event horizon in a birefringent nanophotonic waveguide.

PubMed

Ciret, Charles; Gorza, Simon-Pierre

2016-06-15

The scattering of a linear wave on an optical event horizon, induced by a cross-polarized soliton, is experimentally and numerically investigated in integrated structures. The experiments are performed in a dispersion-engineered birefringent silicon nanophotonic waveguide. In stark contrast with copolarized waves, the large difference between the group velocity of the two cross-polarized waves enables a frequency conversion almost independent of the soliton wavelength. It is shown that the generated idler is only shifted by 10 nm around 1550 nm over a pump tuning range of 350 nm. Simulations using two coupled full vectorial nonlinear Schrödinger equations fully support the experimental results.
Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP).

PubMed

Turner, E L; Metcalfe, C; Donovan, J L; Noble, S; Sterne, J A C; Lane, J A; Avery, K N; Down, L; Walsh, E; Davis, M; Ben-Shlomo, Y; Oliver, S E; Evans, S; Brindle, P; Williams, N J; Hughes, L J; Hill, E M; Davies, C; Ng, S Y; Neal, D E; Hamdy, F C; Martin, R M

2014-06-10

Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing. Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up. Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices). The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.
Virtual reality training in laparoscopic surgery: A systematic review & meta-analysis.

PubMed

Alaker, Medhat; Wynn, Greg R; Arulampalam, Tan

2016-05-01

Laparoscopic surgery requires a different and sometimes more complex skill set than does open surgery. Shortened working hours, less training times, and patient safety issues necessitates that these skills need to be acquired outside the operating room. Virtual reality simulation in laparoscopic surgery is a growing field, and many studies have been published to determine its effectiveness. This systematic review and meta-analysis aims to evaluate virtual reality simulation in laparoscopic abdominal surgery in comparison to other simulation models and to no training. A systematic literature search was carried out until January 2014 in full adherence to PRISMA guidelines. All randomised controlled studies comparing virtual reality training to other models of training or to no training were included. Only studies utilizing objective and validated assessment tools were included. Thirty one randomised controlled trials that compare virtual reality training to other models of training or to no training were included. The results of the meta-analysis showed that virtual reality simulation is significantly more effective than video trainers, and at least as good as box trainers. The use of Proficiency-based VR training, under supervision with prompt instructions and feedback, and the use of haptic feedback, has proven to be the most effective way of delivering the virtual reality training. The incorporation of virtual reality training into surgical training curricula is now necessary. A unified platform of training needs to be established. Further studies to assess the impact on patient outcomes and on hospital costs are necessary. (PROSPERO Registration number: CRD42014010030). Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.
Effect of a high-density foam seating wedge on back pain intensity when used by 14 to 16-year-old school students: a randomised controlled trial.

PubMed

Candy, Elizabeth A; Farewell, Daniel; Jerosch-Herold, Christina; Shepstone, Lee; Watts, Richard A; Stephenson, Richard C

2012-12-01

No previous randomised controlled trials had been undertaken investigating the effect of school seating on back pain in 14 to 16 year olds. This study was designed to test the effect of the use of a high-density foam wedge on normal school seating on the intensity of back pain. Randomised controlled trial. Suffolk, a predominantly rural county in eastern England. One hundred and eighty-five students with back pain were recruited from 12 schools. Randomisation was stratified by school. The control and intervention groups included 92 and 83 students, respectively. Following a 1-week baseline observation period, each student in the intervention group was given a wedge to use on their school chairs. The primary outcome measure was pain intensity (numerical rating scale, 0 to 10) recorded in pain diaries over 4 weeks. Random effects models were used to analyse the pain intensity data. Ninety-seven students (46 control group, 51 intervention group) completed the trial. For the intervention group, pain intensity was reduced significantly over the 3 weeks of wedge use. The average reduction in pain intensity was estimated to be 0.709 points (95% confidence interval 0.341 to 1.077), representing a 58% reduction in back pain for those in the intervention group. Use of a wedge reduced the intensity of back pain significantly, especially in the evenings. The results suggest that further research into the longer-term effect of seating on pain intensity in adolescents should be considered. Copyright © 2011 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
A community-based cluster randomised trial of safe storage to reduce pesticide self-poisoning in rural Sri Lanka: study protocol

PubMed Central

2011-01-01

Background The WHO recognises pesticide poisoning to be the single most important means of suicide globally. Pesticide self-poisoning is a major public health and clinical problem in rural Asia, where it has led to case fatality ratios 20-30 times higher than self-poisoning in the developed world. One approach to reducing access to pesticides is for households to store pesticides in lockable "safe-storage" containers. However, before this approach can be promoted, evidence is required on its effectiveness and safety. Methods/Design A community-based cluster randomised controlled trial has been set up in 44,000 households in the North Central Province, Sri Lanka. A census is being performed, collecting baseline demographic data, socio-economic status, pesticide usage, self-harm and alcohol. Participating villages are then randomised and eligible households in the intervention arm given a lockable safe storage container for agrochemicals. The primary outcome will be incidence of pesticide self-poisoning over three years amongst individuals aged 14 years and over. 217,944 person years of follow-up are required in each arm to detect a 33% reduction in pesticide self-poisoning with 80% power at the 5% significance level. Secondary outcomes will include the incidence of all pesticide poisoning and total self-harm. Discussion This paper describes a large effectiveness study of a community intervention to reduce the burden of intentional poisoning in rural Sri Lanka. The study builds on a strong partnership between provincial health services, local and international researchers, and local communities. We discuss issues in relation to randomisation and contamination, engaging control villages, the intervention, and strategies to improve adherence. Trial Registritation The trial is registered on ClinicalTrials.gov ref: NCT1146496 (http://clinicaltrialsfeeds.org/clinical-trials/show/NCT01146496). PMID:22104027
Neurofeedback ineffective in paediatric brain tumour survivors: Results of a double-blind randomised placebo-controlled trial.

PubMed

de Ruiter, Marieke Anna; Oosterlaan, Jaap; Schouten-van Meeteren, Antoinette Yvonne Narda; Maurice-Stam, Heleen; van Vuurden, Dannis Gilbert; Gidding, Corrie; Beek, Laura Rachel; Granzen, Bernd; Caron, Huib N; Grootenhuis, Martha Alexandra

2016-09-01

Many paediatric brain tumour survivors (PBTS) suffer from neurocognitive impairments. Promising effects of neurofeedback (NF) on neurocognitive functioning have been reported, however research into NF for PBTS has not been conducted. We investigated the effects of NF on neurocognitive functioning in PBTS using a double-blind randomised placebo-controlled trial with a parallel-group design (Pediatric Research on Improving Speed, Memory, and Attention; the PRISMA study). Eligible for inclusion were PBTS with neurocognitive complaints, aged 8-18 years, >2 years post-treatment. They were recruited from five medical centres in the Netherlands. A randomisation table assigned participants to 30 sessions (two per week) of either NF or placebo feedback (PF) (ratio 1:1). Participants, parents, trainers, and researchers handling the data were blinded to group assignment. Participants were assessed pre-, post- and 6 months post-training to determine whether NF training would lead to improved functioning as compared with PF training. Primary outcome measures were attention, processing speed, memory, executive functioning, visuomotor integration, and intelligence. Linear mixed models analyses were used to test differences between NF and PF training over time. A total of 82 children were enrolled (mean age 13.9 years, standard deviation = 3.2, 49% males); 80 participants were randomised (NF: n = 40, PF n = 40); 71 participants completed the training (NF: n = 34, PF: n = 37); 68 participants completed training and 6 months post-training assessment (NF: n = 33, PF: n = 35). Similar improvements were found over time for the two treatment groups on the primary outcomes (all p's > 0.15). Results indicated no specific treatment-effects of NF on neurocognitive functioning of PBTS. Copyright © 2016 Elsevier Ltd. All rights reserved.
Pre-EDIT: protocol for a randomised feasibility trial of elastance-directed intrapleural catheter or talc pleurodesis (EDIT) in malignant pleural effusion

PubMed Central

Martin, Geoffrey A; Tsim, Selina; Kidd, Andrew C; Foster, John E; McLoone, Philip; Chalmers, Anthony

2018-01-01

Introduction Non-expansile lung (NEL) is a common cause of talc pleurodesis (TP) failure in malignant pleural effusion (MPE), but is often occult prior to drainage. Reliable detection of NEL would allow patients to be allocated between intrapleural catheter (IPC) and TP. High pleural elastance (PEL) has been associated with NEL in observational studies. Pre-EDIT is a randomised feasibility trial of elastance-directed IPC or TP (EDIT) management using a novel, purpose-built digital pleural manometer (Rocket Medical, UK). Methods and analysis Consecutive patients with MPE without prior evidence of NEL or preference for IPC will be randomised 1:1 between EDIT management and standard care (an attempt at TP). The primary objective is to determine whether sufficient numbers of patients (defined as 30 within 12 months (or 15 over 6 months)) can be recruited and randomised to justify a subsequent phase III trial testing the efficacy of EDIT management. Secondary objectives include safety, technical feasibility and validation of study design elements, including the definition of PEL using 4D pleural MRI before and after fluid aspiration. EDIT involves PEL assessment during a large volume pleural fluid aspiration, followed by an attempt at TP or placement of an IPC within 24 hours. Patients will be allocated to IPC if the rolling average PEL sustained over at least 250 mL fluid aspirated (PEL250) is ≥ 14.5 cm H2O/L. Ethics and dissemination Pre-EDIT was approved by the West of Scotland Regional Ethics Committee on 8 March 2017 (Ref: 17/WS/0042). Results will be presented at scientific meetings and published in peer-reviewed journals. Trial registration number NCT03319186; Pre-results. PMID:29862030
Vertical Transport by Coastal Mesoscale Convective Systems

NASA Astrophysics Data System (ADS)

Lombardo, K.; Kading, T.

2016-12-01

This work is part of an ongoing investigation of coastal mesoscale convective systems (MCSs), including changes in vertical transport of boundary layer air by storms moving from inland to offshore. The density of a storm's cold pool versus that of the offshore marine atmospheric boundary layer (MABL), in part, determines the ability of the storm to successfully cross the coast, the mechanism driving storm propagation, and the ability of the storm to lift air from the boundary layer aloft. The ability of an MCS to overturn boundary layer air can be especially important over the eastern US seaboard, where warm season coastal MCSs are relatively common and where large coastal population centers generate concentrated regions of pollution. Recent work numerically simulating idealized MCSs in a coastal environment has provided some insight into the physical mechanisms governing MCS coastal crossing success and the impact on vertical transport of boundary layer air. Storms are simulated using a cloud resolving model initialized with atmospheric conditions representative of a Mid-Atlantic environment. Simulations are run in 2-D at 250 m horizontal resolution with a vertical resolution stretched from 100 m in the boundary layer to 250 m aloft. The left half of the 800 km domain is configured to represent land, while the right half is assigned as water. Sensitivity experiments are conducted to quantify the influence of varying MABL structure on MCS coastal crossing success and air transport, with MABL values representative of those observed over the western Mid-Atlantic during warm season. Preliminary results indicate that when the density of the cold pool is much greater than the MABL, the storm successfully crosses the coastline, with lifting of surface parcels, which ascend through the troposphere. When the density of the cold pool is similar to that of the MABL, parcels within the MABL remain at low levels, though parcels above the MABL ascend through the troposphere.
Ab initio state-specific N2 + O dissociation and exchange modeling for molecular simulations

NASA Astrophysics Data System (ADS)

Luo, Han; Kulakhmetov, Marat; Alexeenko, Alina

2017-02-01

Quasi-classical trajectory (QCT) calculations are used in this work to calculate state-specific N2(X1Σ ) +O(3P ) →2 N(4S ) +O(3P ) dissociation and N2(X1Σ ) +O(3P ) →NO(X2Π ) +N(4S ) exchange cross sections and rates based on the 13A″ and 13A' ab initio potential energy surface by Gamallo et al. [J. Chem. Phys. 119, 2545-2556 (2003)]. The calculations consider translational energies up to 23 eV and temperatures between 1000 K and 20 000 K. Vibrational favoring is observed for dissociation reaction at the whole range of collision energies and for exchange reaction around the dissociation limit. For the same collision energy, cross sections for v = 30 are 4 to 6 times larger than those for the ground state. The exchange reaction has an effective activation energy that is dependent on the initial rovibrational level, which is different from dissociation reaction. In addition, the exchange cross sections have a maximum when the total collision energy (TCE) approaches dissociation energy. The calculations are used to generate compact QCT-derived state-specific dissociation (QCT-SSD) and QCT-derived state-specific exchange (QCT-SSE) models, which describe over 1 × 106 cross sections with about 150 model parameters. The models can be used directly within direct simulation Monte Carlo and computational fluid dynamics simulations. Rate constants predicted by the new models are compared to the experimental measurements, direct QCT calculations and predictions by other models that include: TCE model, Bose-Candler QCT-based exchange model, Macheret-Fridman dissociation model, Macheret's exchange model, and Park's two-temperature model. The new models match QCT-calculated and experimental rates within 30% under nonequilibrium conditions while other models under predict by over an order of magnitude under vibrationally-cold conditions.
Transition path time distributions for Lévy flights

NASA Astrophysics Data System (ADS)

Janakiraman, Deepika

2018-07-01

This paper presents a study of transition path time distributions for Lévy noise-induced barrier crossing. Transition paths are short segments of the reactive trajectories and span the barrier region of the potential without spilling into the reactant/product wells. The time taken to traverse this segment is referred to as the transition path time. Since the transition path is devoid of excursions in the minimum, the corresponding time will give the exclusive barrier crossing time, unlike . This work explores the distribution of transition path times for superdiffusive barrier crossing, analytically. This is made possible by approximating the barrier by an inverted parabola. Using this approximation, the distributions are evaluated in both over- and under-damped limits of friction. The short-time behaviour of the distributions, provide analytical evidence for single-step transition events—a feature in Lévy-barrier crossing as observed in prior simulation studies. The average transition path time is calculated as a function of the Lévy index (α), and the optimal value of α leading to minimum average transition path time is discussed, in both the limits of friction. Langevin dynamics simulations corroborating with the analytical results are also presented.
HIV-Tat immunization induces cross-clade neutralizing antibodies and CD4(+) T cell increases in antiretroviral-treated South African volunteers: a randomized phase II clinical trial.

PubMed

Ensoli, Barbara; Nchabeleng, Maphoshane; Ensoli, Fabrizio; Tripiciano, Antonella; Bellino, Stefania; Picconi, Orietta; Sgadari, Cecilia; Longo, Olimpia; Tavoschi, Lara; Joffe, Daniel; Cafaro, Aurelio; Francavilla, Vittorio; Moretti, Sonia; Pavone Cossut, Maria Rosaria; Collacchi, Barbara; Arancio, Angela; Paniccia, Giovanni; Casabianca, Anna; Magnani, Mauro; Buttò, Stefano; Levendal, Elise; Ndimande, John Velaphi; Asia, Bennett; Pillay, Yogan; Garaci, Enrico; Monini, Paolo

2016-06-09

Although combined antiretroviral therapy (cART) has saved millions of lives, it is incapable of full immune reconstitution and virus eradication. The transactivator of transcription (Tat) protein is a key human immunodeficiency virus (HIV) virulence factor required for virus replication and transmission. Tat is expressed and released extracellularly by infected cells also under cART and in this form induces immune dysregulation, and promotes virus reactivation, entry and spreading. Of note, anti-Tat antibodies are rare in natural infection and, when present, correlate with asymptomatic state and reduced disease progression. This suggested that induction of anti-Tat antibodies represents a pathogenesis-driven intervention to block progression and to intensify cART. Indeed Tat-based vaccination was safe, immunogenic and capable of immune restoration in an open-label, randomized phase II clinical trial conducted in 168 cART-treated volunteers in Italy. To assess whether B-clade Tat immunization would be effective also in patients with different genetic background and infecting virus, a phase II trial was conducted in South Africa. The ISS T-003 was a 48-week randomised, double-blinded, placebo-controlled trial to evaluate immunogenicity (primary endpoint) and safety (secondary endpoint) of B-clade Tat (30 μg) given intradermally, three times at 4-week intervals, in 200 HIV-infected adults on effective cART (randomised 1:1) with CD4(+) T-cell counts ≥200 cells/µL. Study outcomes also included cross-clade anti-Tat antibodies, neutralization, CD4(+) T-cell counts and therapy compliance. Immunization was safe and well-tolerated and induced durable, high titers anti-Tat B-clade antibodies in 97 % vaccinees. Anti-Tat antibodies were cross-clade (all vaccinees tested) and neutralized Tat-mediated entry of oligomeric B-clade and C-clade envelope in dendritic cells (24 participants tested). Anti-Tat antibody titers correlated positively with neutralization. Tat vaccination increased CD4(+) T-cell numbers (all participants tested), particularly when baseline levels were still low after years of therapy, and this had a positive correlation with HIV neutralization. Finally, in cART non-compliant patients (24 participants), vaccination contained viral load rebound and maintained CD4(+) T-cell numbers over study entry levels as compared to placebo. The data indicate that Tat vaccination can restore the immune system and induces cross-clade neutralizing anti-Tat antibodies in patients with different genetic backgrounds and infecting viruses, supporting the conduct of phase III studies in South Africa. Trial registration ClinicalTrials.gov NCT01513135, 01/23/2012.
Calibration Matters: Advances in Strapdown Airborne Gravimetry

NASA Astrophysics Data System (ADS)

Becker, D.

2015-12-01

Using a commercial navigation-grade strapdown inertial measurement unit (IMU) for airborne gravimetry can be advantageous in terms of cost, handling, and space consumption compared to the classical stable-platform spring gravimeters. Up to now, however, large sensor errors made it impossible to reach the mGal-level using such type IMUs as they are not designed or optimized for this kind of application. Apart from a proper error-modeling in the filtering process, specific calibration methods that are tailored to the application of aerogravity may help to bridge this gap and to improve their performance. Based on simulations, a quantitative analysis is presented on how much IMU sensor errors, as biases, scale factors, cross couplings, and thermal drifts distort the determination of gravity and the deflection of the vertical (DOV). Several lab and in-field calibration methods are briefly discussed, and calibration results are shown for an iMAR RQH unit. In particular, a thermal lab calibration of its QA2000 accelerometers greatly improved the long-term drift behavior. Latest results from four recent airborne gravimetry campaigns confirm the effectiveness of the calibrations applied, with cross-over accuracies reaching 1.0 mGal (0.6 mGal after cross-over adjustment) and DOV accuracies reaching 1.1 arc seconds after cross-over adjustment.
Sleep positioning systems for children with cerebral palsy.

PubMed

Blake, Sharon F; Logan, Stuart; Humphreys, Ginny; Matthews, Justin; Rogers, Morwenna; Thompson-Coon, Joanna; Wyatt, Katrina; Morris, Christopher

2015-01-01

Sleep positioning systems can be prescribed for children with cerebral palsy to help reduce or prevent hip migration, provide comfort to ease pain and/or improve sleep. As sleep disturbance is common in children with developmental disabilities, with impact on their carers' sleep, and as sleep positioning systems can be expensive, guidance is needed to support decisions as to their use. To determine whether commercially-available sleep positioning systems, compared with usual care, reduce or prevent hip migration in children with cerebral palsy. Any negative effect of sleep positioning systems on hip migration will be considered within this objective.Secondary objectives were to determine the effect of sleep positioning systems on: (1) number or frequency of hip problems; (2) sleep patterns and quality; (3) quality of life of the child and family; (4) pain; and (5) physical functioning. We also sought to identify any adverse effects from using sleep positioning systems. In December 2014, we searched CENTRAL, Ovid MEDLINE, Embase, and 13 other databases. We also searched two trials registers. We applied no restrictions on date of publication, language, publication status or study design. We checked references and contacted manufacturers and authors for potentially relevant literature, and searched the internet using Google. We included all randomised controlled trials (RCTs) evaluating whole body sleep positioning systems for children and adolescents (up to 18 years of age) with cerebral palsy. Two review authors independently screened reports retrieved from the search against pre-determined inclusion criteria and assessed the quality of eligible studies.Members of the public (parent carers of children with neurodisability) contributed to this review by suggesting the topic, refining the research objectives, interpreting the findings, and reviewing the plain language summary. We did not identify any randomised controlled trials that evaluated the effectiveness of sleep positioning systems on hip migration.We did find two randomised cross-over trials that met the inclusion criteria in respect of secondary objectives relating to sleep quality and pain. Neither study reported any important difference between sleeping in sleep positioning systems and not for sleep patterns or sleep quality (two studies, 21 children, very low quality evidence) and pain (one study, 11 children, very low quality evidence). These were small studies with established users of sleep positioning systems and were judged to have high risk of bias.We found no eligible trials that explored the other secondary objectives (number or frequency of hip problems, quality of life of the child and family, physical functioning, and adverse effects). We found no randomised trials that evaluated the effectiveness of sleep positioning systems to reduce or prevent hip migration in children with cerebral palsy. Nor did we find any randomised trials that evaluated the effect of sleep positioning systems on the number or frequency of hip problems, quality of life of the child and family or on physical functioning.Limited data from two randomised trials, which evaluated the effectiveness of sleep positioning systems on sleep quality and pain for children with cerebral palsy, showed no significant differences in these aspects of health when children were using and not using a sleep positioning system.In order to inform clinical decision-making and the prescription of sleep positioning systems, more rigorous research is needed to determine effectiveness, cost-effectiveness, and the likelihood of adverse effects.
Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia

PubMed Central

2013-01-01

Background As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. Methods We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon’s two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Results Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. Conclusions SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics. PMID:23819695
Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia.

PubMed

Yap, Christina; Pettitt, Andrew; Billingham, Lucinda

2013-07-03

As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon's two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics.
Virtual reality as a tool for cross-cultural communication: an example from military team training

NASA Astrophysics Data System (ADS)

Downes-Martin, Stephen; Long, Mark; Alexander, Joanna R.

1992-06-01

A major problem with communication across cultures, whether professional or national, is that simple language translation if often insufficient to communicate the concepts. This is especially true when the communicators come from highly specialized fields of knowledge or from national cultures with long histories of divergence. This problem becomes critical when the goal of the communication is national negotiation dealing with such high risk items as arms negotiation or trade wars. Virtual Reality technology has considerable potential for facilitating communication across cultures, by immersing the communicators within multiple visual representations of the concepts, and providing control over those representations. Military distributed team training provides a model for virtual reality suitable for cross cultural communication such as negotiation. In both team training and negotiation, the participants must cooperate, agree on a set of goals, and achieve mastery over the concepts being negotiated. Team training technologies suitable for supporting cross cultural negotiation exist (branch wargaming, computer image generation and visualization, distributed simulation), and have developed along different lines than traditional virtual reality technology. Team training de-emphasizes the realism of physiological interfaces between the human and the virtual reality, and emphasizes the interaction of humans with each other and with intelligent simulated agents within the virtual reality. This approach to virtual reality is suggested as being more fruitful for future work.

How can you capture cultural dynamics?

PubMed Central

Kashima, Yoshihisa

2014-01-01

Cross-cultural comparison is a critical method by which we can examine the interaction between culture and psychological processes. However, comparative methods tend to overlook cultural dynamics – the formation, maintenance, and transformation of cultures over time. The present article gives a brief overview of four different types of research designs that have been used to examine cultural dynamics in the literature: (1) cross-temporal methods that trace medium- to long-term changes in a culture; (2) cross-generational methods that explore medium-term implications of cultural transmission; (3) experimental simulation methods that investigate micro-level mechanisms of cultural dynamics; and (4) formal models and computer simulation methods often used to investigate long-term and macro-level implications of micro-level mechanisms. These methods differ in terms of level of analysis for which they are designed (micro vs. macro-level), scale of time for which they are typically used (short-, medium-, or long-term), and direction of inference (deductive vs. empirical method) that they imply. The paper describes examples of these methods, discuss their strengths and weaknesses, and point to their complementarity in inquiries about cultural change. Because cultural dynamics research is about meaning over time, issues deriving from interpretation of meaning and temporal distance between researchers and objects of inquiry can pose threats to the validity of the research and its findings. The methodological question about hermeneutic circle is recalled and further inquiries are encouraged. PMID:25309476
Comment on "Analysis of single-layer metamaterial absorber with reflection theory" [J. Appl. Phys. 117, 154906 (2015)

NASA Astrophysics Data System (ADS)

Tung, Nguyen Thanh

2016-03-01

In a recent paper, Xiong et al. [J. Appl. Phys. 117, 154906 (2015)] presented the simulated results of a Jerusalem-cross structure in an attempt to elaborate their proposed reflection theory for metamaterial absorbers. Noting that even at non-resonant frequencies the real part of the permeability shows an over-high average value and its imaginary part drops abruptly from positivity to negativity, we argue that their simulated results are unphysical, resulting from an incomplete understanding of the retrieval procedure.
General practitioner use of a C-reactive protein point-of-care test to help target antibiotic prescribing in patients with acute exacerbations of chronic obstructive pulmonary disease (the PACE study): study protocol for a randomised controlled trial.

PubMed

Bates, Janine; Francis, Nick A; White, Patrick; Gillespie, David; Thomas-Jones, Emma; Breen, Rachel; Kirby, Nigel; Hood, Kerry; Gal, Micaela; Phillips, Rhiannon; Naik, Gurudutt; Cals, Jochen; Llor, Carl; Melbye, Hasse; Wootton, Mandy; Riga, Evgenia; Cochrane, Ann; Howe, Robin; Fitzsimmons, Deborah; Sewell, Bernadette; Alam, Mohammed Fasihul; Butler, Christopher C

2017-09-29

Most patients presenting with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) in primary care are prescribed an antibiotic, which may not always be appropriate and may cause harm. C-reactive protein (CRP) is an acute-phase biomarker that can be rapidly measured at the point of care and may predict benefit from antibiotic treatment in AECOPD. It is not clear whether the addition of a CRP point-of-care test (POCT) to clinical assessment leads to a reduction in antibiotic consumption without having a negative impact on COPD health status. This is a multicentre, individually randomised controlled trial (RCT) aiming to include 650 participants with a diagnosis of AECOPD in primary care. Participants will be randomised to be managed according to usual care (control) or with the addition of a CRP POCT to guide antibiotic prescribing. Antibiotic consumption for AECOPD within 4 weeks post randomisation and COPD health status (total score) measured by the Clinical COPD Questionnaire (CCQ) at 2 weeks post randomisation will be co-primary outcomes. Primary analysis (by intention-to-treat) will determine differences in antibiotic consumption for superiority and COPD health status for non-inferiority. Secondary outcomes include: COPD health status, CCQ domain scores, use of other COPD treatments (weeks 1, 2 and 4), EQ-5D utility scores (weeks 1, 2 and 4 and month 6), disease-specific, health-related quality of life (HRQoL) at 6 months, all-cause antibiotic consumption (antibiotic use for any condition) during first 4 weeks post randomisation, total antibiotic consumption (number of days during first 4 weeks of antibiotic consumed for AECOPD/any reason), antibiotic prescribing at the index consultation and during following 4 weeks, adverse effects over the first 4 weeks, incidence of pneumonia (weeks 4 and 6 months), health care resource use and cost comparison over the 6 months following randomisation. Prevalence and resistance profiles of bacteria will be assessed using throat and sputum samples collected at baseline and 4-week follow-up. A health economic evaluation and qualitative process evaluation will be carried out. If shown to be effective (i.e. leads to a reduction in antibiotic use with no worse COPD health status), the use of the CRP POCT could lead to better outcomes for patients with AECOPD and help reduce selective pressures driving the development of antimicrobial resistance. PACE will be one of the first studies to evaluate the cost-effectiveness of a POCT biomarker to guide clinical decision-making in primary care on patient-reported outcomes, antibiotic prescribing and antibiotic resistance for AECOPD. ISRCTN registry, ID: ISRCTN24346473 . Registered on 20 August 2014.
Simulation of the modern arctic climate by the NCAR CCM1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bromwich, D.H.; Tzeng, R.Y.; Parish, T.R.

The NCAR CCM1's simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the ECMWF global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate. The results show that the model simulates anomalously low SLP, too much activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland. First, the broadened Greenlandmore » topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial [open quotes]circum-Greenland[close quotes] trough. These biases are significantly alleviated when the horizontal resolution increases to T42. Over the Arctic basin, the modal simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. 26 refs., 14 figs., 42 tabs.« less
Bistatic radar cross section of a perfectly conducting rhombus-shaped flat plate

NASA Astrophysics Data System (ADS)

Fenn, Alan J.

1990-05-01

The bistatic radar cross section of a perfectly conducting flat plate that has a rhombus shape (equilateral parallelogram) is investigated. The Ohio State University electromagnetic surface patch code (ESP version 4) is used to compute the theoretical bistatic radar cross section of a 35- x 27-in rhombus plate at 1.3 GHz over the bistatic angles 15 deg to 142 deg. The ESP-4 computer code is a method of moments FORTRAN-77 program which can analyze general configurations of plates and wires. This code has been installed and modified at Lincoln Laboratory on a SUN 3 computer network. Details of the code modifications are described. Comparisons of the method of moments simulations and measurements of the rhombus plate are made. It is shown that the ESP-4 computer code provides a high degree of accuracy in the calculation of copolarized and cross-polarized bistatic radar cross section patterns.
A cross-validation package driving Netica with python

USGS Publications Warehouse

Fienen, Michael N.; Plant, Nathaniel G.

2014-01-01

Bayesian networks (BNs) are powerful tools for probabilistically simulating natural systems and emulating process models. Cross validation is a technique to avoid overfitting resulting from overly complex BNs. Overfitting reduces predictive skill. Cross-validation for BNs is known but rarely implemented due partly to a lack of software tools designed to work with available BN packages. CVNetica is open-source, written in Python, and extends the Netica software package to perform cross-validation and read, rebuild, and learn BNs from data. Insights gained from cross-validation and implications on prediction versus description are illustrated with: a data-driven oceanographic application; and a model-emulation application. These examples show that overfitting occurs when BNs become more complex than allowed by supporting data and overfitting incurs computational costs as well as causing a reduction in prediction skill. CVNetica evaluates overfitting using several complexity metrics (we used level of discretization) and its impact on performance metrics (we used skill).
Cross-diffusion-driven hydrodynamic instabilities in a double-layer system: General classification and nonlinear simulations

NASA Astrophysics Data System (ADS)

Budroni, M. A.

2015-12-01

Cross diffusion, whereby a flux of a given species entrains the diffusive transport of another species, can trigger buoyancy-driven hydrodynamic instabilities at the interface of initially stable stratifications. Starting from a simple three-component case, we introduce a theoretical framework to classify cross-diffusion-induced hydrodynamic phenomena in two-layer stratifications under the action of the gravitational field. A cross-diffusion-convection (CDC) model is derived by coupling the fickian diffusion formalism to Stokes equations. In order to isolate the effect of cross-diffusion in the convective destabilization of a double-layer system, we impose a starting concentration jump of one species in the bottom layer while the other one is homogeneously distributed over the spatial domain. This initial configuration avoids the concurrence of classic Rayleigh-Taylor or differential-diffusion convective instabilities, and it also allows us to activate selectively the cross-diffusion feedback by which the heterogeneously distributed species influences the diffusive transport of the other species. We identify two types of hydrodynamic modes [the negative cross-diffusion-driven convection (NCC) and the positive cross-diffusion-driven convection (PCC)], corresponding to the sign of this operational cross-diffusion term. By studying the space-time density profiles along the gravitational axis we obtain analytical conditions for the onset of convection in terms of two important parameters only: the operational cross-diffusivity and the buoyancy ratio, giving the relative contribution of the two species to the global density. The general classification of the NCC and PCC scenarios in such parameter space is supported by numerical simulations of the fully nonlinear CDC problem. The resulting convective patterns compare favorably with recent experimental results found in microemulsion systems.
Maximum drag reduction asymptotes and the cross-over to the Newtonian plug

NASA Astrophysics Data System (ADS)

Benzi, R.; de Angelis, E.; L'Vov, V. S.; Procaccia, I.; Tiberkevich, V.

2006-03-01

We employ the full FENE-P model of the hydrodynamics of a dilute polymer solution to derive a theoretical approach to drag reduction in wall-bounded turbulence. We recapture the results of a recent simplified theory which derived the universal maximum drag reduction (MDR) asymptote, and complement that theory with a discussion of the cross-over from the MDR to the Newtonian plug when the drag reduction saturates. The FENE-P model gives rise to a rather complex theory due to the interaction of the velocity field with the polymeric conformation tensor, making analytic estimates quite taxing. To overcome this we develop the theory in a computer-assisted manner, checking at each point the analytic estimates by direct numerical simulations (DNS) of viscoelastic turbulence in a channel.
Migration and head penetration of Vitamin-E diffused cemented polyethylene cup compared to standard cemented cup in total hip arthroplasty: study protocol for a randomised, double-blind, controlled trial (E1 HIP).

PubMed

Sköldenberg, Olof; Rysinska, Agata; Chammout, Ghazi; Salemyr, Mats; Muren, Olle; Bodén, Henrik; Eisler, Thomas

2016-07-07

In vitro, Vitamin-E-diffused, highly cross-linked polyethylene (PE) has been shown to have superior wear resistance and improved mechanical properties when compared to those of standard highly cross-linked PE liners used in total hip arthroplasty (THA). The aim of the study is to evaluate the safety of a new cemented acetabular cup with Vitamin-E-doped PE regarding migration, head penetration and clinical results. In this single-centre, double-blinded, randomised controlled trial, we will include 50 patients with primary hip osteoarthritis scheduled for THA and randomise them in a 1:1 ratio to a cemented cup with either argon gas-sterilised PE (control group) or Vitamin-E-diffused PE (vitamin-e group). All patients and the assessor of the primary outcome will be blinded and the same uncemented stem will be used for all participants. The primary end point will be proximal migration of the cup at 2 years after surgery measured with radiostereometry. Secondary end points include proximal migration at other follow-ups, total migration, femoral head penetration, clinical outcome scores and hip-related complications. Patients will be followed up at 3 months and at 1, 2, 5 and 10 years postoperatively. Results will be analysed using 95% CIs for the effect size. A regression model will also be used to adjust for stratification factors. The ethical committee at Karolinska Institutet has approved the study. The first results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals when the last patient included has been followed up for 2 years. NCT02254980. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Migration and head penetration of Vitamin-E diffused cemented polyethylene cup compared to standard cemented cup in total hip arthroplasty: study protocol for a randomised, double-blind, controlled trial (E1 HIP)

PubMed Central

Sköldenberg, Olof; Rysinska, Agata; Chammout, Ghazi; Salemyr, Mats; Muren, Olle; Bodén, Henrik; Eisler, Thomas

2016-01-01

Introduction In vitro, Vitamin-E-diffused, highly cross-linked polyethylene (PE) has been shown to have superior wear resistance and improved mechanical properties when compared to those of standard highly cross-linked PE liners used in total hip arthroplasty (THA). The aim of the study is to evaluate the safety of a new cemented acetabular cup with Vitamin-E-doped PE regarding migration, head penetration and clinical results. Methods and analysis In this single-centre, double-blinded, randomised controlled trial, we will include 50 patients with primary hip osteoarthritis scheduled for THA and randomise them in a 1:1 ratio to a cemented cup with either argon gas-sterilised PE (control group) or Vitamin-E-diffused PE (vitamin-e group). All patients and the assessor of the primary outcome will be blinded and the same uncemented stem will be used for all participants. The primary end point will be proximal migration of the cup at 2 years after surgery measured with radiostereometry. Secondary end points include proximal migration at other follow-ups, total migration, femoral head penetration, clinical outcome scores and hip-related complications. Patients will be followed up at 3 months and at 1, 2, 5 and 10 years postoperatively. Results Results will be analysed using 95% CIs for the effect size. A regression model will also be used to adjust for stratification factors. Ethics and dissemination The ethical committee at Karolinska Institutet has approved the study. The first results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals when the last patient included has been followed up for 2 years. Trial registration number NCT02254980. PMID:27388352
β-Blockers for the prevention of acute exacerbations of chronic obstructive pulmonary disease (βLOCK COPD): a randomised controlled study protocol

PubMed Central

Bhatt, Surya P; Connett, John E; Voelker, Helen; Lindberg, Sarah M; Westfall, Elizabeth; Wells, J Michael; Lazarus, Stephen C; Criner, Gerard J; Dransfield, Mark T

2016-01-01

Introduction A substantial majority of chronic obstructive pulmonary disease (COPD)-related morbidity, mortality and healthcare costs are due to acute exacerbations, but existing medications have only a modest effect on reducing their frequency, even when used in combination. Observational studies suggest β-blockers may reduce the risk of COPD exacerbations; thus, we will conduct a randomised, placebo-controlled trial to definitively assess the impact of metoprolol succinate on the rate of COPD exacerbations. Methods and analyses This is a multicentre, placebo-controlled, double-blind, prospective randomised trial that will enrol 1028 patients with at least moderately severe COPD over a 3-year period. Participants with at least moderate COPD will be randomised in a 1:1 fashion to receive metoprolol or placebo; the cohort will be enriched for patients at high risk for exacerbations. Patients will be screened and then randomised over a 2-week period and will then undergo a dose titration period for the following 6 weeks. Thereafter, patients will be followed for 42 additional weeks on their target dose of metoprolol or placebo followed by a 4-week washout period. The primary end point is time to first occurrence of an acute exacerbation during the treatment period. Secondary end points include rates and severity of COPD exacerbations; rate of major cardiovascular events; all-cause mortality; lung function (forced expiratory volume in 1 s (FEV1)); dyspnoea; quality of life; exercise capacity; markers of cardiac stretch (pro-NT brain natriuretic peptide) and systemic inflammation (high-sensitivity C reactive protein and fibrinogen). Analyses will be performed on an intent-to-treat basis. Ethics and dissemination The study protocol has been approved by the Department of Defense Human Protection Research Office and will be approved by the institutional review board of all participating centres. Study findings will be disseminated through presentations at national and international conferences and publications in peer-reviewed journals. Trial registration number NCT02587351; Pre-results. PMID:27267111
β-Blockers for the prevention of acute exacerbations of chronic obstructive pulmonary disease (βLOCK COPD): a randomised controlled study protocol.

PubMed

Bhatt, Surya P; Connett, John E; Voelker, Helen; Lindberg, Sarah M; Westfall, Elizabeth; Wells, J Michael; Lazarus, Stephen C; Criner, Gerard J; Dransfield, Mark T

2016-06-07

A substantial majority of chronic obstructive pulmonary disease (COPD)-related morbidity, mortality and healthcare costs are due to acute exacerbations, but existing medications have only a modest effect on reducing their frequency, even when used in combination. Observational studies suggest β-blockers may reduce the risk of COPD exacerbations; thus, we will conduct a randomised, placebo-controlled trial to definitively assess the impact of metoprolol succinate on the rate of COPD exacerbations. This is a multicentre, placebo-controlled, double-blind, prospective randomised trial that will enrol 1028 patients with at least moderately severe COPD over a 3-year period. Participants with at least moderate COPD will be randomised in a 1:1 fashion to receive metoprolol or placebo; the cohort will be enriched for patients at high risk for exacerbations. Patients will be screened and then randomised over a 2-week period and will then undergo a dose titration period for the following 6 weeks. Thereafter, patients will be followed for 42 additional weeks on their target dose of metoprolol or placebo followed by a 4-week washout period. The primary end point is time to first occurrence of an acute exacerbation during the treatment period. Secondary end points include rates and severity of COPD exacerbations; rate of major cardiovascular events; all-cause mortality; lung function (forced expiratory volume in 1 s (FEV1)); dyspnoea; quality of life; exercise capacity; markers of cardiac stretch (pro-NT brain natriuretic peptide) and systemic inflammation (high-sensitivity C reactive protein and fibrinogen). Analyses will be performed on an intent-to-treat basis. The study protocol has been approved by the Department of Defense Human Protection Research Office and will be approved by the institutional review board of all participating centres. Study findings will be disseminated through presentations at national and international conferences and publications in peer-reviewed journals. NCT02587351; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Bath additives for the treatment of childhood eczema (BATHE): protocol for multicentre parallel group randomised trial.

PubMed

Santer, Miriam; Rumsby, Kate; Ridd, Matthew J; Francis, Nick A; Stuart, Beth; Chorozoglou, Maria; Wood, Wendy; Roberts, Amanda; Thomas, Kim S; Williams, Hywel C; Little, Paul

2015-11-01

Bath emollients are widely prescribed for childhood eczema, yet evidence of their benefits over direct application of emollients is lacking. Objectives To determine the clinical and cost-effectiveness of adding bath emollient to the standard management of eczema in children Pragmatic open 2-armed parallel group randomised controlled trial. General practitioner (GP) practices in England and Wales. Children aged over 12 months and less than 12 years with eczema, excluding inactive or very mild eczema (5 or less on Nottingham Eczema Severity Scale). Children will be randomised to either bath emollients plus standard eczema care or standard eczema care only. Primary outcome is long-term eczema severity, measured by the Patient-Oriented Eczema Measure (POEM) repeated weekly for 16 weeks. Secondary outcomes include: number of eczema exacerbations resulting in healthcare consultations over 1 year; eczema severity over 1 year; disease-specific and generic quality of life; medication use and healthcare resource use; cost-effectiveness. Aiming to detect a mean difference between groups of 2.0 (SD 7.0) in weekly POEM scores over 16 weeks (significance 0.05, power 0.9), allowing for 20% loss to follow-up, gives a total sample size of 423 children. We will use repeated measures analysis of covariance, or a mixed model, to analyse weekly POEM scores. We will control for possible confounders, including baseline eczema severity and child's age. Cost-effectiveness analysis will be carried out from a National Health Service (NHS) perspective. This protocol was approved by Newcastle and North Tyneside 1 NRES committee 14/NE/0098. Follow-up will be completed in 2017. Findings will be disseminated to participants and carers, the public, dermatology and primary care journals, guideline developers and decision-makers. ISRCTN84102309. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Bath additives for the treatment of childhood eczema (BATHE): protocol for multicentre parallel group randomised trial

PubMed Central

Santer, Miriam; Rumsby, Kate; Ridd, Matthew J; Francis, Nick A; Stuart, Beth; Chorozoglou, Maria; Wood, Wendy; Roberts, Amanda; Thomas, Kim S; Williams, Hywel C; Little, Paul

2015-01-01

Introduction Bath emollients are widely prescribed for childhood eczema, yet evidence of their benefits over direct application of emollients is lacking. Objectives To determine the clinical and cost-effectiveness of adding bath emollient to the standard management of eczema in children Methods and analysis Design: Pragmatic open 2-armed parallel group randomised controlled trial. Setting: General practitioner (GP) practices in England and Wales. Participants: Children aged over 12 months and less than 12 years with eczema, excluding inactive or very mild eczema (5 or less on Nottingham Eczema Severity Scale). Interventions: Children will be randomised to either bath emollients plus standard eczema care or standard eczema care only. Outcome measures: Primary outcome is long-term eczema severity, measured by the Patient-Oriented Eczema Measure (POEM) repeated weekly for 16 weeks. Secondary outcomes include: number of eczema exacerbations resulting in healthcare consultations over 1 year; eczema severity over 1 year; disease-specific and generic quality of life; medication use and healthcare resource use; cost-effectiveness. Aiming to detect a mean difference between groups of 2.0 (SD 7.0) in weekly POEM scores over 16 weeks (significance 0.05, power 0.9), allowing for 20% loss to follow-up, gives a total sample size of 423 children. We will use repeated measures analysis of covariance, or a mixed model, to analyse weekly POEM scores. We will control for possible confounders, including baseline eczema severity and child's age. Cost-effectiveness analysis will be carried out from a National Health Service (NHS) perspective. Ethics and dissemination This protocol was approved by Newcastle and North Tyneside 1 NRES committee 14/NE/0098. Follow-up will be completed in 2017. Findings will be disseminated to participants and carers, the public, dermatology and primary care journals, guideline developers and decision-makers. Trial registration number ISRCTN84102309. PMID:26525422
How did a Housing First intervention improve health and social outcomes among homeless adults with mental illness in Toronto? Two-year outcomes from a randomised trial.

PubMed

O'Campo, Patricia; Stergiopoulos, Vicky; Nir, Pam; Levy, Matthew; Misir, Vachan; Chum, Antony; Arbach, Bouchra; Nisenbaum, Rosane; To, Matthew J; Hwang, Stephen W

2016-09-12

We studied the impact of a Housing First (HF) intervention on housing, contact with the justice system, healthcare usage and health outcomes among At Home/Chez Soi randomised trial participants in Toronto, a city with an extensive service network for social and health services for individuals who are experiencing homelessness and mental illness. Participants identified as high needs were randomised to receive either the intervention which provided them with housing and supports by an assertive community treatment team (HF+ACT) or treatment as usual (TAU). Participants (N=197) had in-person interviews every 3 months for 2 years. The HF+ACT group spent more time stably housed compared to the TAU group with the mean difference between the groups of 45.8% (95% CI 37.1% to 54.4%, p<0.0001). Accounting for baseline differences, HF+ACT group showed significant improvements over TAU group for community functioning, selected quality-of-life subscales and arrests at some time points during follow-up. No differences between HF+ACT and TAU groups over the follow-up were observed for health service usage, community integration and substance use. HF for individuals with high levels of need increased housing stability and selected health and justice outcomes over 2 years in a city with many social and health services. ISRCTN42520374. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Randomised controlled trial of reflexology for menopausal symptoms.

PubMed

Williamson, Jan; White, Adrian; Hart, Anna; Ernst, Edzard

2002-09-01

Clinical experience suggests that reflexology may have beneficial effects on the symptoms occurring in menopausal women, particularly psychological symptoms. This study aims to examine that effect rigorously. Randomised controlled trial with two parallel arms. School of Complementary Health in Exeter, Devon, UK. Seventy-six women, aged between 45 and 60 years, reporting menopausal symptoms. Women were randomised to receive nine sessions of either reflexology or nonspecific foot massage (control) by four qualified reflexologists given over a period of 19 weeks. The Women's Health Questionnaire (WHQ), the primary measures being the subscores for anxiety and depression. Severity (visual analogue scale, VAS) and frequency of flushes and night sweats. Mean (SD) scores for anxiety fell from 0.43 (0.29) to 0.22 (0.25) in the reflexology group and from 0.37 (0.27) to 0.27 (0.29) in the control group over the course of treatment. Mean (SD) scores for depression fell from 0.37 (0.25) to 0.20 (0.24) in the reflexology group and from 0.36 (0.23) to 0.20 (0.21) in the control (foot massage) group over the same period. For both scores there was strong evidence of a time effect (P < 0.001) but no evidence of a time-group interaction (P > 0.2). Similar changes were found for severity of hot flushes and night sweats. In the control group, 14/37 believed they had not received true reflexology. Foot reflexology was not shown to be more effective than non-specific foot massage in the treatment of psychological symptoms occurring during the menopause.
Level-crossing statistics of the horizontal wind speed in the planetary surface boundary layer

NASA Astrophysics Data System (ADS)

Edwards, Paul J.; Hurst, Robert B.

2001-09-01

The probability density of the times for which the horizontal wind remains above or below a given threshold speed is of some interest in the fields of renewable energy generation and pollutant dispersal. However there appear to be no analytic or conceptual models which account for the observed power law form of the distribution of these episode lengths over a range of over three decades, from a few tens of seconds to a day or more. We reanalyze high resolution wind data and demonstrate the fractal character of the point process generated by the wind speed level crossings. We simulate the fluctuating wind speed by a Markov process which approximates the characteristics of the real (non-Markovian) wind and successfully generates a power law distribution of episode lengths. However, fundamental questions concerning the physical basis for this behavior and the connection between the properties of a continuous-time stochastic process and the fractal statistics of the point process generated by its level crossings remain unanswered.
Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

PubMed Central

Xia, Feng; Ma, Longhua; Peng, Chen; Sun, Youxian; Dong, Jinxiang

2008-01-01

There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN. PMID:27879934
Retention of laparoscopic procedural skills acquired on a virtual-reality surgical trainer.

PubMed

Maagaard, Mathilde; Sorensen, Jette Led; Oestergaard, Jeanett; Dalsgaard, Torur; Grantcharov, Teodor P; Ottesen, Bent S; Larsen, Christian Rifbjerg

2011-03-01

Virtual-reality (VR) simulator training has been shown to improve surgical performance in laparoscopic procedures in the operating room. We have, in a randomised controlled trial, demonstrated transferability to real operations. The validity of the LapSim virtual-reality simulator as an assessment tool has been demonstrated in several reports. However, an unanswered question regarding simulator training is the durability, or retention, of skills acquired during simulator training. The aim of the present study is to assess the retention of skills acquired using the LapSim VR simulator, 6 and 18 months after an initial training course. The investigation was designed as a 6- and 18-month follow-up on a cohort of participants who earlier participated in a skills training programme on the LapSim VR. The follow-up cohort consisted of trainees and senior consultants allocated to two groups: (1) novices (experience < 5 procedures, n = 9) and (2) experts (experience > 200 procedures during the past 3 years, n = 10). Each participant performed ten sessions. Assessment of skills was based on time, economy of movement and the error parameter "bleeding". The novice group were re-tested after 6 and 18 months, whereas the expert group were only retested once, after 6 months. None of the novices performed laparoscopic surgery in the follow-up period. The experts continued their daily work with laparoscopic surgery. Novices showed retention of skills after 6 months. After 18 months, novices' laparoscopic skills had returned to the pre-training level. This indicates that laparoscopic skills seemed to deteriorate in the period between 6 and 18 months without training. Experts showed consistent performance over time. This information can be included when planning training curricula in minimal invasive surgery.
Randomised controlled trial of the effect of long-term selenium supplementation on plasma cholesterol in an elderly Danish population.

PubMed

Cold, Frederik; Winther, Kristian H; Pastor-Barriuso, Roberto; Rayman, Margaret P; Guallar, Eliseo; Nybo, Mads; Griffin, Bruce A; Stranges, Saverio; Cold, Søren

2015-12-14

Although cross-sectional studies have shown a positive association between Se and cholesterol concentrations, a recent randomised controlled trial in 501 elderly UK individuals of relatively low-Se status found that Se supplementation for 6 months lowered total plasma cholesterol. The Danish PRECISE (PREvention of Cancer by Intervention with Selenium) pilot study (ClinicalTrials.gov ID: NCT01819649) was a 5-year randomised, double-blinded, placebo-controlled trial with four groups (allocation ratio 1:1:1:1). Men and women aged 60-74 years (n 491) were randomised to 100 (n 124), 200 (n 122) or 300 (n 119) μg Se-enriched yeast or matching placebo-yeast tablets (n 126) daily for 5 years. A total of 468 participants continued the study for 6 months and 361 participants, equally distributed across treatment groups, continued for 5 years. Plasma samples were analysed for total and HDL-cholesterol and for total Se concentrations at baseline, 6 months and 5 years. The effect of different doses of Se supplementation on plasma lipid and Se concentrations was estimated by using linear mixed models. Plasma Se concentration increased significantly and dose-dependently in the intervention groups after 6 months and 5 years. Total cholesterol decreased significantly both in the intervention groups and in the placebo group after 6 months and 5 years, with small and nonsignificant differences in changes in plasma concentration of total cholesterol, HDL-cholesterol, non-HDL-cholesterol and total:HDL-cholesterol ratio between intervention and placebo groups. The effect of long-term supplementation with Se on plasma cholesterol concentrations or its sub-fractions did not differ significantly from placebo in this elderly population.

How informed is declared altruism in clinical trials? A qualitative interview study of patient decision-making about the QUEST trials (Quality of Life after Mastectomy and Breast Reconstruction).

PubMed

Bidad, Natalie; MacDonald, Lindsay; Winters, Zoë E; Edwards, Sarah J L; Emson, Marie; Griffin, Clare L; Bliss, Judith; Horne, Rob

2016-09-02

Randomised controlled trials (RCTs) often fail to recruit sufficient participants, despite altruism being cited as their motivation. Previous investigations of factors influencing participation decisions have been methodologically limited. This study evaluated how women weigh up different motivations after initially expressing altruism, and explored their understanding of a trial and its alternatives. The trial was the 'Quality of Life after Mastectomy and Breast Reconstruction' (QUEST) trial. Thirty-nine women participated in qualitative interviews 1 month post-surgery. Twenty-seven women (10 trial decliners and 17 acceptors) who spontaneously mentioned 'altruism' were selected for thematic analysis. Verbatim transcripts were coded independently by two researchers. Participants' motivations to accept or decline randomisation were cross-referenced with their understanding of the QUEST trials and the process of randomisation. The seven emerging themes were: (1) altruism expressed by acceptors and decliners; (2) overriding personal needs in decliners; (3) pure altruism in acceptors; (4) 'hypothetical altruism' amongst acceptors; (5) weak altruism amongst acceptors; (6) conditional altruism amongst acceptors; and (7) sense of duty to participate. Poor understanding of the trial rationale and its implications was also evident. Altruism was a motivating factor for participation in the QUEST randomised controlled trials where the main outcomes comprised quality of life and allocated treatments comprised established surgical procedures. Women's decisions were influenced by their understanding of the trial. Both acceptors and decliners of the trial expressed 'altruism', but most acceptors lacked an obvious treatment preference, hoped for personal benefits regarding a treatment allocation, or did not articulate complete understanding of the trial. QUEST A, ISRCTN38846532 ; Date assigned 6 January 2010. QUEST B, ISRCTN92581226 ; Date assigned 6 January 2010.
Promoting public awareness of randomised clinical trials using the media: the 'Get Randomised' campaign.

PubMed

Mackenzie, Isla S; Wei, Li; Rutherford, Daniel; Findlay, Evelyn A; Saywood, Wendy; Campbell, Marion K; Macdonald, Thomas M

2010-02-01

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT * Recruitment is key to the success of clinical trials. * Many clinical trials fail to achieve adequate recruitment. * Public understanding and engagement in clinical research could be improved. WHAT THIS STUDY ADDS * 'Get Randomised' is the first campaign of its kind in the UK. * It is possible to improve public awareness of clinical research using the media. * Further work is needed to determine whether improved public awareness leads to increased participation in clinical research in the future. AIM To increase public awareness and understanding of clinical research in Scotland. METHODS A generic media campaign to raise public awareness of clinical research was launched in 2008. The 'Get Randomised' campaign was a Scotland-wide initiative led by the University of Dundee in collaboration with other Scottish universities. Television, radio and newspaper advertising showed leading clinical researchers, general practitioners and patients informing the public about the importance of randomised clinical trials (RCTs). 'Get Randomised' was the central message and interested individuals were directed to the http://www.getrandomised.org website for more information. To assess the impact of the campaign, cross-sectional surveys were conducted in representative samples of 1040 adults in Scotland prior to campaign launch and again 6 months later. RESULTS There was an improvement in public awareness of clinical trials following the campaign; 56.7% [95% confidence interval (CI) 51.8, 61.6] of the sample recalled seeing or hearing advertising about RCTs following the campaign compared with 14.8% (10.8, 18.9) prior to the campaign launch (difference = 41.4%; 95% CI for difference 35.6, 48.3; P < 0.01). Of those who recalled the advertising, 49% felt that the main message was that people should take part more in medical research. However, on whether they would personally take part in a clinical trial if asked, there was little difference in response following the campaign ['yes' 31.3% (28.4, 34.1) prior; 30.4% (27.6, 33.2) following; difference =-0.9%; 95% CI for difference -4.8, 3.1%; P= 0.92]. CONCLUSIONS It is possible to raise public awareness of clinical research using the media, but further efforts may be required to influence individuals' decisions to take part in clinical research.
The use of pH adjusted lignocaine in controlling operative pain in the day surgery unit: a prospective, randomised trial.

PubMed

Fitton, A R; Ragbir, M; Milling, M A

1996-09-01

We report the results of a randomised, case matched, controlled, double blind study on 40 patients undergoing correction of their prominent ears, comparing efficacy of pH adjusted lignocaine to lignocaine alone in controlling operative pain. Each patient received commercial lignocaine in one ear and the same preparation reconstituted with 1 ml of 8.4% sodium bicarbonate in the other ear according to our randomisation protocol. 30 patients were studied to compare the difference between the buffered and commercial preparation infiltrated at room temperature. A further 10 patients were studied to assess the benefit the buffered preparation at room temperature had over commercial lignocaine warmed to body temperature. Linear analogue pain scores for discomfort at infiltration and during the operation itself were analysed. Buffered lignocaine imparts a significant reduction in pain on infiltration, compared to the commercial preparation at both room and body temperature. Both preparations were equally effective in obliterating pain during the operation itself.
Physical health care monitoring for people with serious mental illness.

PubMed

Tosh, Graeme; Clifton, Andrew; Mala, Shereen; Bachner, Mick

2010-03-17

Current guidance suggests that we should monitor the physical health of people with serious mental illness and there has been a significant financial investment over recent years to provide this. To assess the effectiveness of physical health monitoring as a means of reducing morbidity, mortality and reduction in quality of life in people with serious mental illness. We searched the Cochrane Schizophrenia Group Trials Register (October 2009) which is based on regular searches of CINAHL, EMBASE, MEDLINE and PsycINFO. All randomised or quasi-randomised clinical trials focusing on physical health monitoring versus standard care or comparing i) self monitoring vs monitoring by health care professional; ii) simple vs complex monitoring; iii) specific vs non-specific checks iv) once only vs regular checks or v) comparison of different guidance. The authors (GT, AC, SM) independently screened search results and identified three studies as possibly fulfilling the review's criteria. On examination, however, all three were subsequently excluded. We did not identify any randomised trials which assessed the effectiveness of physical health monitoring in people with serious mental illness. There is no evidence from randomised trials to support current guidance and practice. Guidance and practice are based on expert consensus, clinical experience and good intentions rather than high quality evidence.
A randomised controlled trial evaluating the utility of a patient Decision Aid to improve clinical trial (RAVES 08.03) related decision-making.

PubMed

Sundaresan, Puma; Ager, Brittany; Turner, Sandra; Costa, Dan; Kneebone, Andrew; Pearse, Maria; Woo, Henry; Tesson, Stephanie; Juraskova, Ilona; Butow, Phyllis

2017-10-01

Randomised controlled trials (RCTs) are considered the 'gold-standard' for evaluating medical treatments. However, patients and clinicians report difficulties with informed consent and recruitment. We evaluated the utility of a Decision Aid (DA) in reducing RCT-related decisional conflict, and improving RCT knowledge and recruitment. Potential participants for a radiotherapy RCT were invited to participate in the current study. Participants were randomised to receive the RCT's participant information sheet with or without a DA. Questionnaires were administered at baseline, one and six months. The primary outcome measure was decisional conflict. Secondary outcome measures included knowledge regarding and recruitment to the RCT. 129 men were randomised to the DA (63) and control (66) arms. Decisional conflict was significantly lower over 6-months (p=0.048) in the DA arm. Knowledge regarding the RCT was significantly higher at 6months (p=0.033) in the DA arm. 20.6% of the DA arm (13 of 63) and 9% of the control arm (6 of 66) entered the RCT. This study demonstrates the utility of a DA in reducing decisional conflict and improving trial knowledge in men with cancer who are making decisions regarding RCT participation. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.
Ankle Injury Management (AIM): design of a pragmatic multi-centre equivalence randomised controlled trial comparing Close Contact Casting (CCC) to Open surgical Reduction and Internal Fixation (ORIF) in the treatment of unstable ankle fractures in patients over 60 years

PubMed Central

2014-01-01

Background Ankle fractures account for 9% of all fractures with a quarter of these occurring in adults over 60 years. The short term disability and long-term consequences of this injury can be considerable. Current opinion favours open reduction and internal fixation (ORIF) over non-operative treatment (fracture manipulation and the application of a standard moulded cast) for older people. Both techniques are associated with complications but the limited published research indicates higher complication rates of fracture malunion (poor position at healing) with casting. The aim of this study is to compare ORIF with a modification of existing casting techniques, Close Contact Casting (CCC). We propose that CCC may offer an equivalent functional outcome to ORIF and avoid the risks associated with surgery. Methods/Design This study is a pragmatic multi-centre equivalence randomised controlled trial. 620 participants will be randomised to receive ORIF or CCC after sustaining an isolated displaced unstable ankle fracture. Participants will be recruited from a minimum of 20 National Health Service (NHS) acute hospitals throughout England and Wales. Participants will be aged over 60 years and be ambulatory prior to injury. Follow-up will be at six weeks and six months after randomisation. The primary outcome is the Olerud & Molander Ankle Score, a functional patient reported outcome measure, at 6 months. Follow-up will also include assessments of mobility, ankle range of movement, health related quality of life and complications. The six-month follow-up will be conducted face-to-face by an assessor blinded to the allocated intervention. A parallel economic evaluation will consider both a health service and a broader societal perspective including the individual and their family. In order to explore patient experience of their treatment and recovery, a purposive sample of 40 patients will also be interviewed using a semi-structured interview schedule between 6-10 weeks post treatment. Discussion This multicentre study was open to recruitment July 2010 and recruitment is due to be completed in December 2013. Trial registration Current Controlled Trials ISRCTN04180738. PMID:24621174
How do children learn to cross the street? The process of pedestrian safety training

PubMed Central

Schwebel, David C.; Shen, Jiabin; McClure, Leslie A.

2016-01-01

Objective Pedestrian injuries are a leading cause of child death, and may be reduced by training children to cross streets more safely. Such training is most effective when children receive repeated practice at the complex cognitive-perceptual task of judging moving traffic and selecting safe crossing gaps, but there is limited data on how much practice is required for children to reach adult levels of functioning. Using existing data, we examined how children’s pedestrian skill changed over the course of six pedestrian safety training sessions, each comprised of 45 crossings within a virtual pedestrian environment. Methods As part of a randomized controlled trial on pedestrian safety training, 59 children ages 7-8 crossed the street within a semi-immersive virtual pedestrian environment 270 times over a 3-week period (6 sessions of 45 crossings each). Feedback was provided after each crossing, and traffic speed and density was advanced as children’s skill improved. Post-intervention pedestrian behavior was assessed a week later in the virtual environment and compared to adult behavior with identical traffic patterns. Results Over the course of training, children entered traffic gaps more quickly and chose tighter gaps to cross within; their crossing efficiency appeared to increase. By the end of training, some aspects of children’s pedestrian behavior was comparable to adult behavior but other aspects were not, indicating the training was worthwhile but insufficient for most children to achieve adult levels of functioning. Conclusions Repeated practice in a simulated pedestrian environment helps children learn aspects of safe and efficient pedestrian behavior. Six twice-weekly training sessions of 45 crossings each were insufficient for children to reach adult pedestrian functioning, however, and future research should continue to study the trajectory and quantity of child pedestrian safety training needed for children to become competent pedestrians. PMID:26760077
New non-randomised model to assess the prevalence of discriminating behaviour: a pilot study on mephedrone

PubMed Central

2011-01-01

Background An advantage of randomised response and non-randomised models investigating sensitive issues arises from the characteristic that individual answers about discriminating behaviour cannot be linked to the individuals. This study proposed a new fuzzy response model coined 'Single Sample Count' (SSC) to estimate prevalence of discriminating or embarrassing behaviour in epidemiologic studies. Methods The SSC was tested and compared to the established Forced Response (FR) model estimating Mephedrone use. Estimations from both SSC and FR were then corroborated with qualitative hair screening data. Volunteers (n = 318, mean age = 22.69 ± 5.87, 59.1% male) in a rural area in north Wales and a metropolitan area in England completed a questionnaire containing the SSC and FR in alternating order, and four questions canvassing opinions and beliefs regarding Mephedrone. Hair samples were screened for Mephedrone using a qualitative Liquid Chromatography-Mass Spectrometry method. Results The SSC algorithm improves upon the existing item count techniques by utilizing known population distributions and embeds the sensitive question among four unrelated innocuous questions with binomial distribution. Respondents are only asked to indicate how many without revealing which ones are true. The two probability models yielded similar estimates with the FR being between 2.6% - 15.0%; whereas the new SSC ranged between 0% - 10%. The six positive hair samples indicated that the prevalence rate in the sample was at least 4%. The close proximity of these estimates provides evidence to support the validity of the new SSC model. Using simulations, the recommended sample sizes as the function of the statistical power and expected prevalence rate were calculated. Conclusion The main advantages of the SSC over other indirect methods are: simple administration, completion and calculation, maximum use of the data and good face validity for all respondents. Owing to the key feature that respondents are not required to answer the sensitive question directly, coupled with the absence of forced response or obvious self-protective response strategy, the SSC has the potential to cut across self-protective barriers more effectively than other estimation models. This elegantly simple, quick and effective method can be successfully employed in public health research investigating compromising behaviours. PMID:21812979
Comparison of stapled haemorrhoidopexy with traditional excisional surgery for haemorrhoidal disease (eTHoS): a pragmatic, multicentre, randomised controlled trial.

PubMed

Watson, Angus J M; Hudson, Jemma; Wood, Jessica; Kilonzo, Mary; Brown, Steven R; McDonald, Alison; Norrie, John; Bruhn, Hanne; Cook, Jonathan A

2016-11-12

Two commonly performed surgical interventions are available for severe (grade II-IV) haemorrhoids; traditional excisional surgery and stapled haemorrhoidopexy. Uncertainty exists as to which is most effective. The eTHoS trial was designed to establish the clinical effectiveness and cost-effectiveness of stapled haemorrhoidopexy compared with traditional excisional surgery. The eTHoS trial was a large, open-label, multicentre, parallel-group, pragmatic randomised controlled trial done in adult participants (aged 18 years or older) referred to hospital for surgical treatment for grade II-IV haemorrhoids. Participants were randomly assigned (1:1) to receive either traditional excisional surgery or stapled haemorrhoidopexy. Randomisation was minimised according to baseline EuroQol 5 dimensions 3 level score (EQ-5D-3L), haemorrhoid grade, sex, and centre with an automated system to stapled haemorrhoidopexy or traditional excisional surgery. The primary outcome was area under the quality of life curve (AUC) measured with the EQ-5D-3L descriptive system over 24 months, assessed according to the randomised groups. The primary outcome measure was analysed using linear regression with adjustment for the minimisation variables. This trial is registered with the ISRCTN registry, number ISRCTN80061723. Between Jan 13, 2011, and Aug 1, 2014, 777 patients were randomised (389 to receive stapled haemorrhoidopexy and 388 to receive traditional excisional surgery). Stapled haemorrhoidopexy was less painful than traditional excisional surgery in the short term and surgical complication rates were similar between groups. The EQ-5D-3L AUC score was higher in the traditional excisional surgery group than the stapled haemorrhoidopexy group over 24 months; mean difference -0·073 (95% CI -0·140 to -0·006; p=0·0342). EQ-5D-3L was higher for stapled haemorrhoidopexy in the first 6 weeks after surgery, the traditional excisional surgery group had significantly better quality of life scores than the stapled haemorrhoidopexy group. 24 (7%) of 338 participants who received stapled haemorrhoidopexy and 33 (9%) of 352 participants who received traditional excisional surgery had serious adverse events. As part of a tailored management plan for haemorrhoids, traditional excisional surgery should be considered over stapled haemorrhoidopexy as the surgical treatment of choice. National Institute for Health Research Health Technology Assessment programme. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.
Simulation of Cross-border Impacts Resulting from Classical Swine Fever Epidemics within the Netherlands and Germany.

PubMed

Hop, G E; Mourits, M C M; Oude Lansink, A G J M; Saatkamp, H W

2016-02-01

The cross-border region of the Netherlands (NL) and the two German states of North Rhine Westphalia (NRW) and Lower Saxony (LS) is a large and highly integrated livestock production area. This region increasingly develops towards a single epidemiological area in which disease introduction is a shared veterinary and, consequently, economic risk. The objectives of this study were to examine classical swine fever (CSF) control strategies' veterinary and direct economic impacts for NL, NRW and LS given the current production structure and to analyse CSF's cross-border causes and impacts within the NL-NRW-LS region. The course of the epidemic was simulated by the use of InterSpread Plus, whereas economic analysis was restricted to calculating disease control costs and costs directly resulting from the control measures applied. Three veterinary control strategies were considered: a strategy based on the minimum EU requirements, a vaccination and a depopulation strategy based on NL and GER's contingency plans. Regardless of the veterinary control strategy, simulated outbreak sizes and durations for 2010 were much smaller than those simulated previously, using data from over 10 years ago. For example, worst-case outbreaks (50th percentile) in NL resulted in 30-40 infected farms and lasted for two to four and a half months; associated direct costs and direct consequential costs ranged from €24.7 to 28.6 million and €11.7 to 26.7 million, respectively. Both vaccination and depopulation strategies were efficient in controlling outbreaks, especially large outbreaks, whereas the EU minimum strategy was especially deficient in controlling worst-case outbreaks. Both vaccination and depopulation strategies resulted in low direct costs and direct consequential costs. The probability of cross-border disease spread was relatively low, and cross-border spread resulted in small, short outbreaks in neighbouring countries. Few opportunities for further cross-border harmonization and collaboration were identified, including the implementation of cross-border regions (free and diseased regions regardless of the border) in case of outbreaks within close proximity of the border, and more and quicker sharing of information across the border. It was expected, however, that collaboration to mitigate the market effects of an epidemic will create more opportunities to lower the impact of CSF outbreaks in a cross-border context. © 2014 Blackwell Verlag GmbH.
Advantages and disadvantages of graduated and inverse graduated compression hosiery in patients with chronic venous insufficiency and healthy volunteers: A prospective, mono-centric, blinded, open randomised, controlled and cross-over trial.

PubMed

Riebe, Helene; Konschake, Wolfgang; Haase, Hermann; Jünger, Michael

2018-02-01

Background The therapeutic effectiveness of compression therapy depends on the selection of compression hosiery. Objectives To assess efficacy and tolerability of graduated elastic compression stockings (GECS) and inverse graduated elastic compression stockings (PECS). Methods Thirty-two healthy volunteers and thirty-two patients with chronic venous insufficiency were analysed; wear period: one week for each stocking type (randomised, blinded). volume reduction of 'Lower leg' (Image3D®) and 'Distal leg and foot' (water plethysmography). clinical symptoms of chronic venous insufficiency assessed by the Venous Clinical Severity Score, side effects and wear comfort in both groups. Results Volume of 'Lower leg': significant reduction in healthy volunteers (mean GECS: -37.5 mL, mean PECS: -37.2 mL) and in patients (mean GECS: -55.6 mL, mean PECS: -41.6 mL). Volume of 'Distal lower leg and foot': significant reduction in healthy volunteers (mean GECS: -27 mL, mean PECS: -16.7 mL), significant reduction in patients by GECS (mean: -43.4 mL), but non-significant reduction by PECS (mean: -22.6 mL). Clinical symptoms of chronic venous insufficiency were improved significantly better with GECS than with PECS, p < 0.001. GECS led to more painful constrictions, p = 0.047, PECS slipped down more often, p < 0.001. Conclusion GECS and PECS reduce volume of the segment 'Lower leg' in patients and healthy volunteers. Patients' volume of the 'Distal lower leg and foot', however, were diminished significantly only by GECS ( p = 0.0001). Patients' complaints were improved by both GECS and PECS, and GECS were superior to PECS.
Wheat bran extract alters colonic fermentation and microbial composition, but does not affect faecal water toxicity: a randomised controlled trial in healthy subjects.

PubMed

Windey, Karen; De Preter, Vicky; Huys, Geert; Broekaert, Willem F; Delcour, Jan A; Louat, Thierry; Herman, Jean; Verbeke, Kristin

2015-01-28

Wheat bran extract (WBE), containing arabinoxylan-oligosaccharides that are potential prebiotic substrates, has been shown to modify bacterial colonic fermentation in human subjects and to beneficially affect the development of colorectal cancer (CRC) in rats. However, it is unclear whether these changes in fermentation are able to reduce the risk of developing CRC in humans. The aim of the present study was to evaluate the effects of WBE on the markers of CRC risk in healthy volunteers, and to correlate these effects with colonic fermentation. A total of twenty healthy subjects were enrolled in a double-blind, cross-over, randomised, controlled trial in which the subjects ingested WBE (10 g/d) or placebo (maltodextrin, 10 g/d) for 3 weeks, separated by a 3-week washout period. At the end of each study period, colonic handling of NH3 was evaluated using the biomarker lactose[15N, 15N']ureide, colonic fermentation was characterised through a metabolomics approach, and the predominant microbial composition was analysed using denaturing gradient gel electrophoresis. As markers of CRC risk, faecal water genotoxicity was determined using the comet assay and faecal water cytotoxicity using a colorimetric cell viability assay. Intake of WBE induced a shift from urinary to faecal 15N excretion, indicating a stimulation of colonic bacterial activity and/or growth. Microbial analysis revealed a selective stimulation of Bifidobacterium adolescentis. In addition, WBE altered the colonic fermentation pattern and significantly reduced colonic protein fermentation compared with the run-in period. However, faecal water cytotoxicity and genotoxicity were not affected. Although intake of WBE clearly affected colonic fermentation and changed the composition of the microbiota, these changes were not associated with the changes in the markers of CRC risk.
Remineralisation by chewing sugar-free gums in a randomised, controlled in situ trial including dietary intake and gauze to promote plaque formation.

PubMed

Cochrane, N J; Shen, P; Byrne, S J; Walker, G D; Adams, G G; Yuan, Y; Reynolds, C; Hoffmann, B; Dashper, S G; Reynolds, E C

2012-01-01

Remineralisation has been shown to be an effective mechanism of preventing the progression of enamel caries. The aim of this double-blind, randomised, cross-over in situ study was to compare enamel remineralisation by chewing sugar-free gum with or without casein phosphopeptide amorphous calcium phosphate (CPP-ACP) where the enamel lesions were exposed to dietary intake and some were covered with gauze to promote plaque formation. Participants wore removable palatal appliances containing 3 recessed enamel half-slabs with subsurface lesions covered with gauze and 3 without gauze. Mineral content was measured by transverse microradiography, and plaque composition was analysed by real-time polymerase chain reaction. For both the gauze-free and gauze-covered lesions, the greatest amount of remineralisation was produced by the CPP-ACP sugar-free gum, followed by the gum without CPP-ACP and then the no-gum control. Recessing the enamel in the appliance allowed plaque accumulation without the need for gauze. There was a trend of less remineralisation and greater variation in mineral content for the gauze-covered lesions. The cell numbers of total bacteria and streptococci were slightly higher in the plaque from the gauze-covered enamel for 2 of the 3 treatment legs; however, there was no significant difference in Streptococcus mutans cell numbers. In conclusion, chewing sugar-free gum containing CPP-ACP promoted greater levels of remineralisation than a sugar-free gum without CPP-ACP or a no-gum control using an in situ remineralisation model including dietary intake irrespective of whether gauze was used to promote plaque formation or not. Copyright © 2012 S. Karger AG, Basel.
Effect of whole-body mild-cold exposure on arterial stiffness and central haemodynamics: a randomised, cross-over trial in healthy men and women.

PubMed

King, Sibella G; Ahuja, Kiran D K; Wass, Jezreel; Shing, Cecilia M; Adams, Murray J; Davies, Justin E; Sharman, James E; Williams, Andrew D

2013-05-01

Aortic pulse wave velocity (PWV) and augmentation index (AIx) are independent predictors of cardiovascular risk and mortality, but little is known about the effect of air temperature changes on these variables. Our study investigated the effect of exposure to whole-body mild-cold on measures of arterial stiffness (aortic and brachial PWV), and on central haemodynamics [including augmented pressure (AP), AIx], and aortic reservoir components [including reservoir and excess pressures (P ex)]. Sixteen healthy volunteers (10 men, age 43 ± 19 years; mean ± SD) were randomised to be studied under conditions of 12 °C (mild-cold) and 21 °C (control) on separate days. Supine resting measures were taken at baseline (ambient temperature) and after 10, 30, and 60 min exposure to each experimental condition in a climate chamber. There was no significant change in brachial blood pressure between mild-cold and control conditions. However, compared to control, AP [+2 mmHg, 95 % confidence interval (CI) 0.36-4.36; p = 0.01] and AIx (+6 %, 95 % CI 1.24-10.1; p = 0.02) increased, and time to maximum P ex (a component of reservoir function related to timing of peak aortic in-flow) decreased (-7 ms, 95 % CI -15.4 to 2.03; p = 0.01) compared to control. Yet there was no significant change in aortic PWV (+0.04 m/s, 95 % CI -0.47 to 0.55; p = 0.87) or brachial PWV (+0.36 m/s; -0.41 to 1.12; p = 0.35) between conditions. We conclude that mild-cold exposure increases central haemodynamic stress and alters timing of peak aortic in-flow without differentially affecting arterial stiffness.
Effectiveness of portable electronic and optical magnifiers for near vision activities in low vision: a randomised crossover trial.

PubMed

Taylor, John J; Bambrick, Rachel; Brand, Andrew; Bray, Nathan; Dutton, Michelle; Harper, Robert A; Hoare, Zoe; Ryan, Barbara; Edwards, Rhiannon T; Waterman, Heather; Dickinson, Christine

2017-07-01

To compare the performance of near vision activities using additional portable electronic vision enhancement systems (p-EVES), to using optical magnifiers alone, by individuals with visual impairment. A total of 100 experienced optical aid users were recruited from low vision clinics at Manchester Royal Eye Hospital, Manchester, UK, to a prospective two-arm cross-over randomised controlled trial. Reading, performance of near vision activities, and device usage were evaluated at baseline; and at the end of each study arm (Intervention A: existing optical aids plus p-EVES; Intervention B: optical aids only) which was after 2 and 4 months. A total of 82 participants completed the study. Overall, maximum reading speed for high contrast sentences was not statistically significantly different for optical aids and p-EVES, although the critical print size and threshold print size which could be accessed with p-EVES were statistically significantly smaller (p < 0.001 in both cases). The optical aids were used for a larger number of tasks (p < 0.001), and used more frequently (p < 0.001). However p-EVES were preferred for leisure reading by 70% of participants, and allowed longer duration of reading (p < 0.001). During the study arm when they had a p-EVES device, participants were able to carry out more tasks independently (p < 0.001), and reported less difficulty with a range of near vision activities (p < 0.001). The study provides evidence that p-EVES devices can play a useful role in supplementing the range of low vision aids used to reduce activity limitation for near vision tasks. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.
An intervention for pulmonary rehabilitators to develop a social identity for patients attending exercise rehabilitation: a feasibility and pilot randomised control trial protocol.

PubMed

Levy, Andrew R; Matata, Bashir; Pilsworth, Sam; Mcgonigle, Adrian; Wigelsworth, Lyndsey; Jones, Linda; Pott, Nicola; Bettany, Max; Midgley, Adrian W

2018-01-01

Chronic obstructive pulmonary disease (COPD) is a degenerative condition that can impair health-related quality of life (HRQoL). A number of self-management interventions, employing a variety of behavioural change techniques (BCTs), have been adopted to improve HRQoL for COPD patients. However, a lack of attention has been given to group management interventions with an emphasis on incorporating BCTs into rehabilitators' practice. This study aims to pilot and feasibly explore a social identity group management intervention, delivered by COPD rehabilitation staff to patients attending exercise pulmonary rehabilitation. Doing so will help inform the plausibility of the intervention before conducting a full trial to evaluate its effectiveness to improve HRQoL. This is a two-centre, randomised cross-over controlled trial. Two pulmonary rehabilitation centres based in the UK will be randomly allocated to two treatment arms (standard care and intervention). Outcome measurements relating to HRQoL and social identity will be completed pre- and post-exercise rehabilitation. Focus group interviews will be conducted at the end of exercise rehabilitation to capture participants' contextualised experiences of the intervention. COPD rehabilitators will undertake semi-structured interviews at the end of the trial to garner their holistic perspectives of intervention fidelity and implementation. This is the first study to adopt a social identity approach to develop a rehabilitator-led, group management intervention for COPD patients attending exercise pulmonary rehabilitation. The results of this study will provide evidence for the feasibility and sample size requirements to inform a larger study, which can ascertain the intervention's effectiveness for improving HRQoL for COPD patients. ClinicalTrials.gov NCT02288039. Date 31 October 2014.
Do healthy school meals affect illness, allergies and school attendance in 8- to 11-year-old children? A cluster-randomised controlled study.

PubMed

Laursen, R P; Lauritzen, L; Ritz, C; Dyssegaard, C B; Astrup, A; Michaelsen, K F; Damsgaard, C T

2015-05-01

A nutritionally adequate diet in childhood is important for health and resistance of allergies and infections. This study explored the effects of school meals rich in fish, vegetables and fibre on school attendance, asthma, allergies and illness in 797 Danish 8- to 11-year-old children. No comparable studies conducted in high-income settings have been identified. The OPUS School Meal Study was a cluster-randomised cross-over trial. Children from third and fourth grades at nine Danish schools received school meals or usual packed lunch (control) for two 3-month periods. Occurrence and duration of illnesses, asthma and allergies during the last 14 days were recorded by parental questionnaires at baseline and after each 3-month period. Self-reported well-being was assessed by visual analogue scales. The school meals did not affect school attendance, parent-reported occurrence or duration of asthma and allergies or self-reported well-being. The most common symptoms of illness were stomach pain (24%), headache (28%) and cold (24%). A slightly higher number of children experienced headaches in the school meal (27%) compared with the control period (22%) (P=0.02). However, subgroup analyses showed that this effect was only seen in children eating school meals in the classroom (P=0.007), and not in common dining areas (P=0.2). No effect was found on other symptoms of illness. Provision of nutritionally balanced school meals did not affect school attendance, asthma, allergies, illness or well-being in 8- to 11-year-old children. The slight increase in occurrence of headaches seems to be related to the physical eating environment.
Effects of isoflavone-containing soya protein on ex vivo cholesterol efflux, vascular function and blood markers of CVD risk in adults with moderately elevated blood pressure: a dose-response randomised controlled trial.

PubMed

Richter, Chesney K; Skulas-Ray, Ann C; Fleming, Jennifer A; Link, Christina J; Mukherjea, Ratna; Krul, Elaine S; Kris-Etherton, Penny M

2017-05-01

Emerging CVD risk factors (e.g. HDL function and central haemodynamics) may account for residual CVD risk experienced by individuals who meet LDL-cholesterol and blood pressure (BP) targets. Recent evidence suggests that these emerging risk factors can be modified by polyphenol-rich interventions such as soya, but additional research is needed. This study was designed to investigate the effects of an isoflavone-containing soya protein isolate (delivering 25 and 50 g/d soya protein) on HDL function (i.e. ex vivo cholesterol efflux), macrovascular function and blood markers of CVD risk. Middle-aged adults (n 20; mean age=51·6 (sem 6·6) years) with moderately elevated brachial BP (mean systolic BP=129 (sem 9) mmHg; mean diastolic BP=82·5 (sem 8·4) mmHg) consumed 0 (control), 25 and 50 g/d soya protein in a randomised cross-over design. Soya and control powders were consumed for 6 weeks each with a 2-week compliance break between treatment periods. Blood samples and vascular function measures were obtained at baseline and following each supplementation period. Supplementation with 50 g/d soya protein significantly reduced brachial diastolic BP (-2·3 mmHg) compared with 25 g/d soya protein (Tukey-adjusted P=0·03) but not the control. Soya supplementation did not improve ex vivo cholesterol efflux, macrovascular function or other blood markers of CVD risk compared with the carbohydrate-matched control. Additional research is needed to clarify whether effects on these CVD risk factors depend on the relative health of participants and/or equol producing capacity.
Impact of N-acetylcysteine on endothelial function, B-type natriuretic peptide and renal function in patients with the cardiorenal syndrome: a pilot cross over randomised controlled trial.

PubMed

Camuglia, Anthony C; Maeder, Micha T; Starr, Jennifer; Farrington, Catherine; Kaye, David M

2013-04-01

Both heart and renal failure are characterised by increased systemic oxidative stress and endothelial dysfunction and occur in the cardiorenal syndrome (CRS). The aim of the present study was to assess the impact of N-acetylcysteine (NAC), a potent antioxidant, on endothelial function, B-type natriuretic peptide (BNP) and renal function in patients with CRS. In a double blind, placebo controlled manner, we randomised nine stable outpatients with both heart failure (LVEF<40% and NYHA class II or III) and renal failure (Cockroft Gault clearance of 20-60ml/min) to placebo or NAC (500mg orally twice daily) for 28 days followed by a wash out period (>7 days) and crossover to the other treatment. Eight patients completed the study and all data (N=9) was used in the analysis. Mean forearm blood flow improved significantly with NAC with mean ratio of improvement of 1.99 (SEM: ±0.49) for NAC and 0.73 (SEM: ±0.23) for placebo with a p-value of 0.047. There was no significant difference in BNP (p=0.25), renal function (p=0.71) or NYHA class (p=0.5). No deaths occurred during the trial. In this pilot trial of patients with CRS, NAC therapy was associated with improved forearm blood flow. This may represent a general improvement in endothelial function and warrants further investigation of antioxidant therapy in these patients. Copyright © 2012 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
Postprandial effects of test meals including concentrated arabinoxylan and whole grain rye in subjects with the metabolic syndrome: a randomised study.

PubMed

Hartvigsen, M L; Lærke, H N; Overgaard, A; Holst, J J; Bach Knudsen, K E; Hermansen, K

2014-05-01

Prospective studies have shown an inverse relationship between whole grain consumption and the risk of type 2 diabetes, where short chain fatty acids (SCFA) may be involved. Our objective was to determine the effect of isolated arabinoxylan alone or in combination with whole grain rye kernels on postprandial glucose, insulin, free fatty acids (FFA), gut hormones, SCFA and appetite in subjects with the metabolic syndrome (MetS). Fifteen subjects with MetS participated in this acute, randomised, cross-over study. The test meals each providing 50 g of digestible carbohydrate were as follows: semolina porridge added concentrated arabinoxylan (AX), rye kernels (RK) or concentrated arabinoxylan combined with rye kernels (AXRK) and semolina porridge as control (SE). A standard lunch was served 4 h after the test meals. Blood samples were drawn during a 6-h period, and appetite scores and breath hydrogen were assessed every 30 min. The AXRK meal reduced the acute glucose (P=0.005) and insulin responses (P<0.001) and the feeling of hunger (P=0.005; 0-360 min) compared with the control meal. The AX and AXRK meals increased butyrate and acetate concentrations after 6 h. No significant differences were found for the second meal responses of glucose, insulin, FFA, glucagon-like peptide-1 or ghrelin. Our results indicate a stimulatory effect of arabinoxylan on butyrate and acetate production, however, with no detectable effect on the second meal glucose response. It remains to be tested in a long-term study if a beneficial effect on the glucose response of the isolated arabinoxylan will be related to the SCFA production.

Nebulised 7% hypertonic saline improves lung function and quality of life in bronchiectasis.

PubMed

Kellett, Fiona; Robert, Niven M

2011-12-01

Sputum retention is a distressing feature of non-cystic fibrosis bronchiectasis and has been shown to contribute to the vicious cycle of infection seen in this disease. In a previous study we demonstrated that nebulised 7% hypertonic saline was both safe and effective in this patient population. Patients with a clinical diagnosis of non-cystic fibrosis bronchiectasis, confirmed by HRCT, were entered into a randomised single blind cross-over study to evaluate 0.9% sodium chloride (IS) and 7% hypertonic saline (HS). Following a 4 week run in patients received a random order active HS or IS daily for 3 months. A 4 week wash-out phase was included between phases. We report lung function, quality of life, and health care utilisation responses. 32 patients mean age 56.6 years (SD 14.6), 16 male, were recruited of which 28 were randomised and completed the study. Lung function (%change from baseline) improved in HS vs. IS (FEV(1): 15.1, 1.8 p<0.01; FVC: 11.2, 0.7 p<0.01. SGRQ improved significantly from baseline (HS 6.0, IS 1.2; p<0.05). There were reductions in annualised antibiotic usage (HS 2.4, IS 5.4 courses per patient per year), annualised emergency health care utilisation visits were reduced (HS 2.1, IS 4.9 events per patient per year). There were also improvements in sputum viscosity and ease of expectoration (visual analogue scale). Regular use of 7% hypertonic saline improves lung function, quality of life and health care utilisation in non-cystic fibrosis bronchiectasis patients. Copyright © 2011 Elsevier Ltd. All rights reserved.
A randomised crossover trial of minimising medical terminology in secondary care correspondence in patients with chronic health conditions: impact on understanding and patient reported outcomes.

PubMed

Wernick, M; Hale, P; Anticich, N; Busch, S; Merriman, L; King, B; Pegg, T

2016-05-01

There is little existing research on the role that secondary care letters have in ensuring patient understanding of chronic health conditions. To determine whether minimising the use of medical terminology in medical correspondence improved patient understanding and anxiety/depression scores. A single-centre, non-blinded, randomised crossover design assessed health literacy, EQ-5D scores and the impact of the 'translated' letter on the doctor's professionalism, the patient's relationship with their general practitioner (GP) and their perceived impact on chronic disease management. Patients were crossed over between their 'translated' and original letter. Sixty patients were recruited. Use of a 'translated' letter reduced mean terms not understood from 7.78 to 1.76 (t(58) = 4.706, P < 0.001). Most patients (78.0%) preferred the 'translated' letter, with 69.5% patients perceiving an enhancement in their doctor's professionalism (z = 2.864, P = 0.004), 69.0% reporting a positive influence on relationship with their GP (z = 2.943, P = 0.003) and 79.7% reporting an increase in perceived ability to manage their chronic health condition with the 'translated' letter (z = 4.601, P < 0.001). There was no effect on EQ-5D depression/anxiety scores. Minimising the use of medical terminology in medical correspondence significantly improved patient understanding and perception of their ability to manage their chronic health condition. Although there was no impact on EQ-5D depression/anxiety scores, overwhelming patient preference for the 'translated' letter indicates a need for minimisation of medical terminology in medical correspondence for patients with chronic health conditions. © 2016 Royal Australasian College of Physicians.
Inhibition of crossed-beam energy transfer induced by expansion-velocity fluctuations

NASA Astrophysics Data System (ADS)

Neuville, C.; Glize, K.; Loiseau, P.; Masson-Laborde, P.-E.; Debayle, A.; Casanova, M.; Baccou, C.; Labaune, C.; Depierreux, S.

2018-04-01

Crossed-beam energy transfer between three laser beams has been experimentally investigated in a flowing plasma. Time-evolution measurements of the amplification of a first beam by a second beam highlighted the inhibition of energy transfer by hydrodynamic modifications of the plasma in the crossing volume due to the propagation of a third beam. According to 3D simulations and an analytical model, it appears that the long-wavelength expansion-velocity fluctuations produced by the propagation of the third beam in the crossing volume are responsible for this mitigation of energy transfer. This effect could be a cause of the over-estimation of the amount of the transferred energy in indirect-drive inertial confinement fusion experiments. Besides, tuning such long-wavelength fluctuations could be a way to completely inhibit CBET at the laser entrance holes of hohlraums.
Protocol of a Multicenter International Randomized Controlled Manikin Study on Different Protocols of Cardiopulmonary Resuscitation for laypeople (MANI-CPR)

PubMed Central

Contri, Enrico; Burkart, Roman; Borrelli, Paola; Ferraro, Ottavia Eleonora; Tonani, Michela; Cutuli, Amedeo; Bertaia, Daniele; Iozzo, Pasquale; Tinguely, Caroline; Lopez, Daniel; Boldarin, Susi; Deiuri, Claudio; Dénéréaz, Sandrine; Dénéréaz, Yves; Terrapon, Michael; Tami, Christian; Cereda, Cinzia; Somaschini, Alberto; Cornara, Stefano; Cortegiani, Andrea

2018-01-01

Introduction Out-of-hospital cardiac arrest is one of the leading causes of death in industrialised countries. Survival depends on prompt identification of cardiac arrest and on the quality and timing of cardiopulmonary resuscitation (CPR) and defibrillation. For laypeople, there has been a growing interest on hands-only CPR, meaning continuous chest compression without interruption to perform ventilations. It has been demonstrated that intentional interruptions in hands-only CPR can increase its quality. The aim of this randomised trial is to compare three CPR protocols performed with different intentional interruptions with hands-only CPR. Methods and analysis This is a prospective randomised trial performed in eight training centres. Laypeople who passed a basic life support course will be randomised to one of the four CPR protocols in an 8 min simulated cardiac arrest scenario on a manikin: (1) 30 compressions and 2 s pause; (2) 50 compressions and 5 s pause; (3) 100 compressions and 10 s pause; (4) hands-only. The calculated sample size is 552 people. The primary outcome is the percentage of chest compression performed with correct depth evaluated by a computerised feedback system (Laerdal QCPR). Ethics and dissemination Due to the nature of the study, we obtained a waiver from the Ethics Committee (IRCCS Policlinico San Matteo, Pavia, Italy). All participants will sign an informed consent form before randomisation. The results of this study will be published in peer-reviewed journal. The data collected will also be made available in a public data repository. Trial registration number NCT02632500. PMID:29674365
The Healthy Lifestyles Programme (HeLP), a novel school-based intervention to prevent obesity in school children: study protocol for a randomised controlled trial

PubMed Central

2013-01-01

Background Over the last three decades there has been a substantial increase in the proportion of children who are overweight or obese. The Healthy Lifestyles Programme (HeLP) is a novel school-based intervention, using highly interactive and creative delivery methods to prevent obesity in children. Methods/Design We describe a cluster randomised controlled trial to evaluate the effectiveness and cost effectiveness of HeLP. The intervention has been developed using intervention mapping (involving extensive stakeholder involvement) and has been guided by the Information, Motivation, Behavioural Skills model. HeLP includes creating a receptive environment, drama activities, goal setting and reinforcement activities and runs over three school terms. Piloting showed that 9 to 10 year olds were the most receptive and participative. This study aims to recruit 1,300 children from 32 schools (over half of which will have ≥19% of pupils eligible for free school meals) from the southwest of England. Participating schools will be randomised to intervention or control groups with baseline measures taken prior to randomisation. The primary outcome is change in body mass index standard deviation score (BMI SDS) at 24 months post baseline. Secondary outcomes include, waist circumference and percent body fat SDS and proportion of children classified as overweight or obese at 18 and 24 months and objectively measured physical activity and food intake at 18 months. Between-group comparisons will be made using random effects regression analysis taking into account the hierarchical nature of the study design. An economic evaluation will estimate the incremental cost-effectiveness of HeLP, compared to control, from the perspective of the National Health Service (NHS)/third party payer. An in-depth process evaluation will provide insight into how HeLP works, and whether there is any differential uptake or engagement with the programme. Discussion The results of the trial will provide evidence on the effectiveness and cost effectiveness of the Healthy Lifestyles Programme in affecting the weight status of children. Trial registration ISRCTN15811706 PMID:23556434
Supplemental parenteral nutrition in critically ill patients: a study protocol for a phase II randomised controlled trial.

PubMed

Ridley, Emma J; Davies, Andrew R; Parke, Rachael; Bailey, Michael; McArthur, Colin; Gillanders, Lyn; Cooper, David J; McGuinness, Shay

2015-12-24

Nutrition is one of the fundamentals of care provided to critically ill adults. The volume of enteral nutrition received, however, is often much less than prescribed due to multiple functional and process issues. To deliver the prescribed volume and correct the energy deficit associated with enteral nutrition alone, parenteral nutrition can be used in combination (termed "supplemental parenteral nutrition"), but benefits of this method have not been firmly established. A multi-centre, randomised, clinical trial is currently underway to determine if prescribed energy requirements can be provided to critically ill patients by using a supplemental parenteral nutrition strategy in the critically ill. This prospective, multi-centre, randomised, stratified, parallel-group, controlled, phase II trial aims to determine whether a supplemental parenteral nutrition strategy will reliably and safely increase energy intake when compared to usual care. The study will be conducted for 100 critically ill adults with at least one organ system failure and evidence of insufficient enteral intake from six intensive care units in Australia and New Zealand. Enrolled patients will be allocated to either a supplemental parenteral nutrition strategy for 7 days post randomisation or to usual care with enteral nutrition. The primary outcome will be the average energy amount delivered from nutrition therapy over the first 7 days of the study period. Secondary outcomes include protein delivery for 7 days post randomisation; total energy and protein delivery, antibiotic use and organ failure rates (up to 28 days); duration of ventilation, length of intensive care unit and hospital stay. At both intensive care unit and hospital discharge strength and health-related quality of life assessments will be undertaken. Study participants will be followed up for health-related quality of life, resource utilisation and survival at 90 and 180 days post randomisation (unless death occurs first). This trial aims to determine if provision of a supplemental parenteral nutrition strategy to critically ill adults will increase energy intake compared to usual care in Australia and New Zealand. Trial outcomes will guide development of a subsequent larger randomised controlled trial. NCT01847534 (First registered 5 February 2013, last updated 14 October 2015).
Guided, internet-based, rumination-focused cognitive behavioural therapy (i-RFCBT) versus a no-intervention control to prevent depression in high-ruminating young adults, along with an adjunct assessment of the feasibility of unguided i-RFCBT, in the REducing Stress and Preventing Depression trial (RESPOND): study protocol for a phase III randomised controlled trial.

PubMed

Cook, Lorna; Watkins, Edward

2016-01-04

Depression is a global health challenge. Prevention is highlighted as a priority to reduce its prevalence. Although effective preventive interventions exist, the efficacy and coverage can be improved. One proposed means to increase efficacy is by using interventions to target specific risk factors, such as rumination. Rumination-focused CBT (RFCBT) was developed to specifically target depressive rumination and reduces acute depressive symptoms and relapse for patients with residual depression in a randomised controlled trial. Preliminary findings from a Dutch randomised prevention trial in 251 high-risk 15- to 22-year-old subjects selected with elevated worry and rumination found that both supported internet-RFBCT and group-delivered RFCBT equally reduced depressive symptoms and the onset of depressive cases over a period of 1 year, relative to the no-intervention control. A phase III randomised controlled trial following the Medical Research Council (MRC) Complex Interventions Framework will extend a Dutch trial to the United Kingdom, with the addition of diagnostic interviews, primarily to test whether guided internet-RFCBT reduces the onset of depression relative to a no-intervention control. High-risk young adults (aged 18 to 24 years), selected with elevated worry/rumination and recruited through university and internet advertisement, will be randomised to receive either guided internet-RFCBT, supported by clinical psychologists or mental health paraprofessionals, or a no-intervention control. As an adjunct arm, participants are also randomised to unguided internet-RFCBT self-help to provide an initial test of the feasibility and effect size of this intervention. While participants are also randomised to unguided internet-RFCBT, the trial was designed and powered as a phase III trial comparing guided internet-RFCBT versus a no-intervention control. In the comparison between these two arms, the primary outcomes are as follows: a) onset of major depressive episode over a 12-month period, assessed with a Structured Clinical Interview for Diagnosis at 3 months (post-intervention), 6 months and 15 months after randomisation. The following secondary outcomes will be recorded: the incidence of generalized anxiety disorder, symptoms of depression and anxiety, and levels of worry and rumination, measured at baseline and at the same follow-up intervals. In relation to the pilot investigation of unguided internet-RFCBT (the adjunct intervention arm), we will assess the feasibility and acceptability of the data-collection procedures, levels of attrition, effect size and acceptability of the unguided internet-RFCBT intervention. Widespread implementation is necessary for effective prevention, suggesting that the internet may be a valuable mode of delivery. Previous research suggests that guided internet-RFCBT reduces incidence rates relative to controls. We are also interested in developing and evaluating an unguided version to potentially increase the availability and reduce the costs. Current Controlled Trials ISRCTN12683436 . Date of registration: 27 October 2014.
Long-lasting insecticide-treated house screens and targeted treatment of productive breeding-sites for dengue vector control in Acapulco, Mexico

PubMed Central

Che-Mendoza, Azael; Guillermo-May, Guillermo; Herrera-Bojórquez, Josué; Barrera-Pérez, Mario; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Arredondo-Jiménez, Juan I.; Sánchez-Tejeda, Gustavo; Vazquez-Prokopec, Gonzalo; Ranson, Hilary; Lenhart, Audrey; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel; Manrique-Saide, Pablo

2015-01-01

Background Long-lasting insecticidal net screens (LLIS) fitted to domestic windows and doors in combination with targeted treatment (TT) of the most productive Aedes aegypti breeding sites were evaluated for their impact on dengue vector indices in a cluster-randomised trial in Mexico between 2011 and 2013. Methods Sequentially over 2 years, LLIS and TT were deployed in 10 treatment clusters (100 houses/cluster) and followed up over 24 months. Cross-sectional surveys quantified infestations of adult mosquitoes, immature stages at baseline (pre-intervention) and in four post-intervention samples at 6-monthly intervals. Identical surveys were carried out in 10 control clusters that received no treatment. Results LLIS clusters had significantly lower infestations compared to control clusters at 5 and 12 months after installation, as measured by adult (male and female) and pupal-based vector indices. After addition of TT to the intervention houses in intervention clusters, indices remained significantly lower in the treated clusters until 18 (immature and adult stage indices) and 24 months (adult indices only) post-intervention. Conclusions These safe, simple affordable vector control tools were well-accepted by study participants and are potentially suitable in many regions at risk from dengue worldwide. PMID:25604761
Effects of the Red Bull energy drink on cognitive function and mood in healthy young volunteers.

PubMed

Wesnes, Keith A; Brooker, Helen; Watson, Anthony W; Bal, Wendy; Okello, Edward

2017-02-01

The present study compared the cognitive and mood effects of two commercially available products, Red Bull energy drink 250 mL and Red Bull Sugarfree energy drink 250 mL, together with a matching placebo 250 mL. Twenty-four healthy young volunteers took part in a randomised, placebo controlled, double-blind, three-way cross-over study. Cognitive function was assessed using an integrated set of nine computerised tests of attention, working and episodic memory. On each study day the volunteers received a standardised breakfast prior to completing a baseline performance on cognitive tests and mood scales, followed by the consumption of the study drink. The cognitive tests and scales were then re-administered at 30, 60 and 90 min post-dose. Red Bull was found to produce significant improvements over both the Sugarfree version and the placebo drink on two composite scores from the six working and episodic memory tests; one combining the 12 accuracy measures from the six tasks and the other the average speed of correct responses from the working memory and episodic recognition memory tasks. These improvements were in the range of a medium effect size, which reflects a substantial enhancement to memory in young volunteers.
Accelerated iTBS treatment in depressed patients differentially modulates reward system activity based on anhedonia.

PubMed

Duprat, Romain; Wu, Guo-Rong; De Raedt, Rudi; Baeken, Chris

2017-08-09

Accelerated intermittent theta-burst stimulation (aiTBS) anti-depressive working mechanisms are still unclear. Because aiTBS may work through modulating the reward system and the level of anhedonia may influence this modulation, we investigated the effect of aiTBS on reward responsiveness in high and low anhedonic MDD patients. In this registered RCT (NCT01832805), 50 MDD patients were randomised to a sham-controlled cross-over aiTBS treatment protocol over the left dorsolateral prefrontal cortex (DLPFC). Patients performed a probabilistic learning task in fMRI before and after each week of stimulation. Task performance analyses did not show any significant effects of aiTBS on reward responsiveness, nor differences between both groups of MDD patients. However, at baseline, low anhedonic patients displayed higher neural activity in the caudate and putamen. After the first week of aiTBS treatment, in low anhedonic patients we found a decreased neural activity within the reward system, in contrast to an increased activity observed in high anhedonic patients. No changes were observed in reward related neural regions after the first week of sham stimulation. Although both MDD groups showed no differences in task performance, our brain imaging findings suggest that left DLPFC aiTBS treatment modulates the reward system differently according to anhedonia severity.
Homeopathic Arnica montana for post-tonsillectomy analgesia: a randomised placebo control trial.

PubMed

Robertson, A; Suryanarayanan, R; Banerjee, A

2007-01-01

To evaluate the efficacy of Homeopathic Arnica in reducing the morbidity following tonsillectomy. Randomised double blind, placebo controlled trial at a tertiary referral centre. 190 patients over the age of 18 undergoing tonsillectomy were randomised into intervention and control groups receiving either Arnica 30c or identical placebo, 2 tablets 6 times in the first post-operative day and then 2 tablets twice a day for the next 7 days. The primary outcome measure was the change in pain scores (visual analogue scale) recorded by the patient on a questionnaire over 14 days post-operatively; Secondary outcome measures were: analgesia consumption, visits to the GP or hospital, antibiotic usage, the day on which their swallowing returned to normal and the day on which they returned to work. 111 (58.4%) completed questionnaires were available for analysis. The Arnica group had a significantly larger drop in pain score from day 1 to day 14 (28.3) compared to the placebo group (23.8) with p < 0.05. The two groups did not differ significantly on analgesic consumption or any of the other secondary outcome measures (number of post-operative visits to GP, use of antibiotics and secondary haemorrhage readmissions). The results of this trial suggest that Arnica montana given after tonsillectomy provides a small, but statistically significant, decrease in pain scores compared to placebo.
Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial

PubMed Central

Hupperts, Raymond; Lycke, Jan; Short, Christine; Gasperini, Claudio; McNeill, Manjit; Medori, Rossella; Tofil-Kaluza, Agata; Hovenden, Maria; Mehta, Lahar R; Elkins, Jacob

2016-01-01

Background: Mobility impairment is a common disability in MS and negatively impacts patients’ lives. Objective: Evaluate the effect of prolonged-release (PR) fampridine (extended-release dalfampridine in the United States) on self-assessed walking disability, dynamic/static balance and safety in patients with MS. Methods: MOBILE was a randomised, double-blind, exploratory, placebo-controlled trial. Patients with progressive/relapsing-remitting MS and Expanded Disability Status Scale score of 4.0–7.0 were treated with PR-fampridine or placebo twice daily for 24 weeks. Efficacy endpoints included change from baseline in the 12-item MS Walking Scale (MSWS-12), Timed Up and Go (TUG) test and Berg Balance Scale (BBS). Results: 132 patients were randomised at 24 sites in six countries. PR-fampridine therapy resulted in greater median improvements from baseline in MSWS-12 score, TUG speed and BBS total score versus placebo over 24 weeks. A higher proportion of patients receiving PR-fampridine versus placebo experienced significant improvements at MSWS-12 improvement thresholds ⩾7 (p = 0.0275), ⩾8 (p = 0.0153) and ⩾9 points (p = 0.0088) and TUG speed thresholds ⩾10% (p = 0.0021) and ⩾15% (p = 0.0262). PR-fampridine was well tolerated. Conclusions: PR-fampridine therapy resulted in early and sustained improvements in broad measures of walking and balance over six months. PMID:25921050
Comparing specialist medical care with specialist medical care plus the Lightning Process for chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME): study protocol for a randomised controlled trial (SMILE Trial).

PubMed

Crawley, Esther; Mills, Nicola; Hollingworth, Will; Deans, Zuzana; Sterne, Jonathan A; Donovan, Jenny L; Beasant, Lucy; Montgomery, Alan

2013-12-26

Chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is a relatively common and potentially serious condition with a limited evidence base for treatment. Specialist treatment for paediatric CFS/ME uses interventions recommended by National Institute for Health and Clinical Excellence (NICE) including cognitive behavioural therapy, graded exercise therapy and activity management. The Lightning Process (LP) is a trademarked intervention derived from osteopathy, life-coaching and neuro-linguistic programming, delivered over three consecutive days as group sessions. Although over 250 children with CFS/ME attend LP courses each year, there are no reported studies on the effectiveness or cost-effectiveness. This pragmatic randomised controlled trial is set within a specialist paediatric CFS/ME service in the south west of England. Children and young people with CFS/ME (n = 80 to 112), aged 12 to 18 years old will be randomised to specialist medical care (SMC) or SMC plus the LP. The primary outcome will be physical function (SF-36 physical function short form) and fatigue (Chalder Fatigue Scale). This study will tell us whether adding the LP to SMC is effective and cost-effective compared to SMC alone. This study will also provide detailed information on the implementation of the LP and SMC. Current Controlled Trials ISRCTN81456207 (31 July 2012).
No difference in acute effects of supplemental v. dietary calcium on blood pressure and microvascular function in obese women challenged with a high-fat meal: a cross-over randomised study.

PubMed

Ferreira, Thaís da Silva; Leal, Priscila Mansur; Antunes, Vanessa Parada; Sanjuliani, Antonio Felipe; Klein, Márcia Regina Simas Torres

2016-11-01

Recent studies suggest that supplemental Ca (SC) increases the risk of cardiovascular events, whereas dietary Ca (DC) decreases the risk of cardiovascular events. Although frequently consumed with meals, it remains unclear whether Ca can mitigate or aggravate the deleterious effects of a high-fat meal on cardiovascular risk factors. This study aimed to evaluate the effects of SC or DC on blood pressure (BP) and microvascular function (MVF) in the postprandial period in obese women challenged with a high-fat meal. In this cross-over controlled trial, sixteen obese women aged 20-50 years were randomly assigned to receive three test meals (2908 kJ (695 kcal); 48 % fat): high DC (HDCM; 547 mg DC), high SC (HSCM; 500 mg SC-calcium carbonate) and low Ca (LCM; 42 mg DC). BP was continuously evaluated from 15 min before to 120 min after meals by digital photoplethysmography. Before and 120 min after meals, participants underwent evaluation of serum Ca and microvascular flow after postocclusive reactive hyperaemia (PORH) by laser speckle contrast imaging. Ionised serum Ca rose significantly only after HSCM. Systolic BP increased after the three meals, whereas diastolic BP increased after LCM and HDCM. Hyperaemia peak, hyperaemia amplitude and AUC evaluated after PORH decreased with LCM. After HDCM, there was a reduction in hyperaemia peak and hyperaemia amplitude, whereas HSCM decreased only hyperaemia peak. However, comparative analyses of the effects of three test meals on serum Ca, BP and MVF revealed no significant meal×time interaction. This study suggests that in obese women SC and DC do not interfere with the effects of a high-fat meal on BP and MVF.
Using environmental engineering to increase hand hygiene compliance: a cross-over study protocol.

PubMed

Schmidtke, Kelly Ann; Aujla, Navneet; Marshall, Tom; Hussain, Abid; Hodgkinson, Gerard P; Arheart, Kristopher; Marti, Joachim; Birnbach, David J; Vlaev, Ivo

2017-09-11

Compliance with hand hygiene recommendations in hospital is typically less than 50%. Such low compliance inevitably contributes to hospital-acquired infections that negatively affect patients' well-being and hospitals' finances. The design of the present study is predicated on the assumption that most people who fail to clean their hands are not doing so intentionally, they just forget. The present study will test whether psychological priming can be used to increase the number of people who clean their hands on entering a ward. Here, we present the protocol for this study. The study will use a randomised cross-over design. During the study, each of four wards will be observed during four conditions: olfactory prime, visual prime, both primes and neither prime. Each condition will be experienced for 42 days followed by a 7-day washout period (total duration of trial=189 days). We will record the number of people who enter each ward and whether they clean their hands during observation sessions, the amount of cleaning material used from the dispensers each week and the number of hospital-acquired infections that occur in each period. The outcomes will be compared using a regression analysis. Following the initial trail, the most effective priming condition will be rolled out for 3 months in all the wards. Research ethics approval was obtained from the South Central-Oxford C Research Ethics Committee (16/SC/0554), the Health Regulatory Authority and the sponsor. ISRCTN (15397624); Edge ID 86357. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Effects of pressure applied during standardized spinal mobilizations on peripheral skin blood flow: A randomised cross-over study.

PubMed

Zegarra-Parodi, Rafael; Pazdernik, Vanessa K; Roustit, Matthieu; Park, Peter Yong Soo; Degenhardt, Brian F

2016-02-01

Peripheral skin blood flow (SBF) changes during and after spinal mobilization (SM), evaluated with laser Doppler flowmetry, may document physiological responses associated with SM. To document variations in SBF during and after application of an SM and evaluate influence of pressure on SBF by applying the same standardized SM with 3 different nonnoxious pressures. Cross-over design with 4 interventions on 4 different days: control (no touch) and 3 SMs applied rhythmically at 5%, 40%, or 80% of pain pressure threshold (sham SM, low-pressure SM, or high-pressure SM, respectively). Thirty-two individuals participated. The inspiratory gasp (IG) test was our positive control of vasoconstriction through excitation of the skin sympathetic nervous activity (SSNA). Each session comprised 5 phases: (1) baseline at the end of a 20-min acclimatization, (2) IG test, (3) post-IG phase, (4) SM phase or no manual contact for control, and (5) post-SM phase. A Biopac MP36 system collected SBF data, and a Novel Pliance-X system recorded pressure data. Equal and significant bilateral vasodilation occurred during application of unilateral sham SM, low-pressure SM, and high-pressure SM. Post-SM significant vasodilation persisted after high-pressure SM. The current study is the first to describe bilateral peripheral SBF changes occurring during and 5 min after application of standardized SMs. Our post-SM vasodilation suggests involvement of mechanisms other than the putative SSNA-excitatory mechanism proposed with skin conductance measurements. Persistence of post-SM vasodilation following only high-pressure SM suggests possible pressure-dependent mechanisms. However, further research is warranted to clarify our findings. Copyright © 2015 Elsevier Ltd. All rights reserved.
Association between organic food consumption and metabolic syndrome: cross-sectional results from the NutriNet-Santé study.

PubMed

Baudry, Julia; Lelong, Hélène; Adriouch, Solia; Julia, Chantal; Allès, Benjamin; Hercberg, Serge; Touvier, Mathilde; Lairon, Denis; Galan, Pilar; Kesse-Guyot, Emmanuelle

2017-08-02

Metabolic syndrome (MetS), a multicomponent condition, is a cardiovascular disease predictor. Although exposure to agricultural pesticides has been suggested as a potential contributor to the rising rates of obesity, type 2 diabetes, and other features of metabolic disorders, no studies have focused on the association between consumption of organic food (produced without synthetic pesticides) and MetS. We aimed to investigate the cross-sectional association between organic food consumption and MetS in French adults to determine whether it would be worth conducting further studies, particularly large prospective and randomised trials. A total of 8174 participants from the NutriNet-Santé study who attended a clinical visit and completed an organic food frequency questionnaire were included in this cross-sectional analysis. We evaluated the association between the proportion of organic food in the diet (overall and by food group) and MetS using Poisson regression models while adjusting for potential confounders. Higher organic food consumption was negatively associated with the prevalence of MetS: adjusted prevalence ratio was 0.69 (95% CI 0.61, 0.78) when comparing the third tertile of proportion of organic food in the diet with the first one (p value <0.0001). Higher consumption of organic plant-based foods was also related to a lower probability of having MetS. In addition, when stratifying by lifestyle factors (nutritional quality of the diet, smoking status, and physical activity), a significant negative association was detected in each subgroup (p values <0.05), except among smokers. Our results showed that a higher organic food consumption was associated with a lower probability of having MetS. Additional prospective studies and randomised trials are required to ascertain the relationship between organic food consumption and metabolic disorders.
Simulation-based ureteroscopy skills training curriculum with integration of technical and non-technical skills: a randomised controlled trial.

PubMed

Brunckhorst, Oliver; Shahid, Shahab; Aydin, Abdullatif; McIlhenny, Craig; Khan, Shahid; Raza, Syed Johar; Sahai, Arun; Brewin, James; Bello, Fernando; Kneebone, Roger; Khan, Muhammad Shamim; Dasgupta, Prokar; Ahmed, Kamran

2015-09-01

Current training modalities within ureteroscopy have been extensively validated and must now be integrated within a comprehensive curriculum. Additionally, non-technical skills often cause surgical error and little research has been conducted to combine this with technical skills teaching. This study therefore aimed to develop and validate a curriculum for semi-rigid ureteroscopy, integrating both technical and non-technical skills teaching within the programme. Delphi methodology was utilised for curriculum development and content validation, with a randomised trial then conducted (n = 32) for curriculum evaluation. The developed curriculum consisted of four modules; initially developing basic technical skills and subsequently integrating non-technical skills teaching. Sixteen participants underwent the simulation-based curriculum and were subsequently assessed, together with the control cohort (n = 16) within a full immersion environment. Both technical (Time to completion, OSATS and a task specific checklist) and non-technical (NOTSS) outcome measures were recorded with parametric and non-parametric analyses used depending on the distribution of our data as evaluated by a Shapiro-Wilk test. Improvements within the intervention cohort demonstrated educational value across all technical and non-technical parameters recorded, including time to completion (p < 0.01), OSATS scores (p < 0.001), task specific checklist scores (p = 0.011) and NOTSS scores (p < 0.001). Content validity, feasibility and acceptability were all demonstrated through curriculum development and post-study questionnaire results. The current developed curriculum demonstrates that integrating both technical and non-technical skills teaching is both educationally valuable and feasible. Additionally, the curriculum offers a validated simulation-based training modality within ureteroscopy and a framework for the development of other simulation-based programmes.
Washout policies in long-term indwelling urinary catheterisation in adults.

PubMed

Hagen, Suzanne; Sinclair, Lesley; Cross, Stephen

2010-03-17

People requiring long-term bladder draining with an indwelling catheter can experience catheter blockage. Regimens involving different solutions can be used to washout catheters with the aim of preventing blockage. To determine if certain washout regimens are better than others in terms of effectiveness, acceptability, complications, quality of life and economics for the management of long-term indwelling urinary catheterisation in adults. We searched the Cochrane Incontinence Group Specialised Trials Register, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, CINAHL and EMBASE (searches last updated April 2009). Additionally, we examined all reference lists of identified trials. All randomised and quasi-randomised trials comparing catheter washout policies (e.g. washout versus no washout, different washout solutions, frequency, duration, volume, concentration, method of administration) in adults (16 years and above) in any setting (i.e. hospital, nursing/residential home, community) with an indwelling urethral or suprapubic catheter for more than 28 days. Data were extracted by three reviewers independently and compared. Disagreements were resolved by discussion. Data were processed as described in the Cochrane Handbook. If the data in trials were not fully reported, clarification was sought from the authors. For categorical outcomes, the numbers reporting an outcome were related to the numbers at risk in each group to derive an risk ratio (RR). For continuous outcomes, means and standard deviations were used to derive weighted mean differences (WMD). No meta-analysis of study results was possible. Five trials met the inclusion criteria involving 242 patients (132 completed) in two cross-over and three parallel-group randomised controlled trials. Only three of the eight pre-stated comparisons were addressed in these trials. Some trials addressed more than one comparison (e.g. washout versus no washout and one type of washout solution versus another). The analyses reported for the two cross-over trials were inappropriate as they were based on differences between groups rather than differences within individuals receiving sequential interventions. Two parallel-group trials had limited value: one combined results for suprapubic and urethral catheters and one had data on only four participants. Only one trial was free of significant methodological limitations, but its sample size was small.Three trials compared no washout with one or more washout solution (saline or acidic solutions) and authors tended to conclude no difference in clinical outcomes between washout and no washout. In the one trial which had data of sufficient quality to allow interpretation, no difference was detected between washout and no washout groups in the rate of symptomatic urinary tract infection or time to first catheter change. Three trials compared different types of solution: saline versus acidic solutions (two trials); saline versus acidic solution versus antibiotic solution (one trial). Authors tended to report no difference between different washout solutions but the data were too few to support their conclusions. The one trial which warranted consideration concluded no difference between saline and an acidic solution in terms of symptomatic urinary tract infections or time to first catheter change. The data from five trials comparing differing washout policies were sparse and trials were generally of poor quality or poorly reported. The evidence was too scanty to conclude whether or not washouts were beneficial. In the first instance we require further rigorous, high quality trials with adequate power to detect any benefit from washout being performed as opposed to none. Then trials comparing different washout solutions, washout volumes, frequencies/timings and routes of administration are needed.
Effects of subacute ingestion of chlorogenic acids on sleep architecture and energy metabolism through activity of the autonomic nervous system: a randomised, placebo-controlled, double-blinded cross-over trial.

PubMed

Park, Insung; Ochiai, Ryuji; Ogata, Hitomi; Kayaba, Momoko; Hari, Sayaka; Hibi, Masanobu; Katsuragi, Yoshihisa; Satoh, Makoto; Tokuyama, Kumpei

2017-04-01

Chlorogenic acids (CGA) are the most abundant polyphenols in coffee. Continuous consumption of CGA reduces body fat and body weight. Since energy metabolism and sleep are controlled by common regulatory factors, consumption of CGA might modulate sleep. Lack of sleep has been identified as a risk factor for obesity, hypertension and type 2 diabetes. The aim of this study was to determine the effects of ingesting CGA over 5 d on energy metabolism and sleep quality in humans. A total of nine healthy subjects (four male and five female) completed a placebo-controlled, double-blinded, cross-over intervention study. Subjects consumed a test beverage containing 0 or 600 mg of CGA for 5 d. On the fifth night, subjects stayed in a whole-room metabolic chamber to measure energy metabolism; sleep was evaluated using polysomnographic recording. It was found that CGA shortened sleep latency (9 (sem 2) v. 16 (sem 4) min, P<0·05) compared with the control, whereas no effect on sleep architecture, such as slow-wave sleep, rapid eye movement or waking after sleep onset, was observed. Indirect calorimetry revealed that consumption of CGA increased fat oxidation (510 (sem 84) kJ/8 h (122 (sem 20) kcal/8 h) v. 331 (sem 79) kJ/8 h (81 (sem 19) kcal/8 h), P<0·05) but did not affect energy expenditure during sleep. Consumption of CGA enhanced parasympathetic activity assessed from heart-rate variability during sleep (999 (sem 77) v. 919 (sem 54), P<0·05). A period of 5-d CGA consumption significantly increased fat oxidation during sleep, suggesting that beverages containing CGA may be beneficial to reduce body fat and prevent obesity. Consumption of CGA shortened sleep latency and did not adversely affect sleep quality.

What's up doc? A national cross-sectional study of psychological wellbeing of hospital doctors in Ireland.

PubMed

Hayes, Blánaid; Prihodova, Lucia; Walsh, Gillian; Doyle, Frank; Doherty, Sally

2017-10-16

To measure levels of psychological distress, psychological wellbeing and self-stigma in hospital doctors in Ireland. National cross-sectional study of randomised sample of hospital doctors. Participants provided sociodemographic data (age, sex, marital status), work grade (consultant, higher/basic specialist trainee), specialty and work hours and completed well-being questionnaires (the Depression Anxiety Stress Scale, WHO Well-being Index, General Health Questionnaire) and single-item scales on self-rated health and self-stigma. Irish publicly funded hospitals and residential institutions. 1749 doctors (response rate of 55%). All hospital specialties were represented except radiology. Half of participants were men (50.5%). Mean hours worked per week were 57 hours. Over half (52%) rated their health as very good/excellent, while 50.5% reported positive subjective well-being (WHO-5). Over a third (35%) experienced psychological distress (General Health Questionnaire 12). Severe/extremely severe symptoms of depression, anxiety and stress were evident in 7.2%, 6.1% and 9.5% of participants (Depression, Anxiety, Stress Scale 21). Symptoms of distress, depression, anxiety and stress were significantly higher and levels of well-being were significantly lower in trainees compared with consultants, and this was not accounted for by differences in sociodemographic variables. Self-stigma was present in 68.4%. The work hours of doctors working in Irish hospitals were in excess of European Working Time Directive's requirements. Just over half of hospital doctors in Ireland had positive well-being. Compared with international evidence, they had higher levels of psychological distress but slightly lower symptoms of depression and anxiety. Two-thirds of respondents reported self-stigma, which is likely to be a barrier to accessing care. These findings have implications for the design of support services for doctors, for discussions on quality of patient care and for future research. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Effectiveness of recruitment to a smartphone-delivered nutrition intervention in New Zealand: analysis of a randomised controlled trial

PubMed Central

Volkova, Ekaterina; Michie, Jo; Corrigan, Callie; Sundborn, Gerhard; Eyles, Helen; Jiang, Yannan; Mhurchu, Cliona Ni

2017-01-01

Objectives Delivery of interventions via smartphone is a relatively new initiative in public health, and limited evidence exists regarding optimal strategies for recruitment. We describe the effectiveness of approaches used to recruit participants to a smartphone-enabled nutrition intervention trial. Methods Internet and social media advertising, mainstream media advertising and research team networks were used to recruit New Zealand adults to a fully automated smartphone-delivered nutrition labelling trial (no face-to-face visits were required). Recruitment of Māori and Pacific participants was a key focus and ethically relevant recruitment materials and approaches were used where possible. The effectiveness of recruitment strategies was evaluated using Google Analytics, monitoring of study website registrations and randomisations, and self-reported participant data. The cost of the various strategies and associations with participant demographics were assessed. Results Over a period of 13 months, there were 2448 registrations on the study website, and 1357 eligible individuals were randomised into the study (55%). Facebook campaigns were the most successful recruitment strategy overall (43% of all randomised participants) and for all ethnic groups (Māori 44%, Pacific 44% and other 43%). Significant associations were observed between recruitment strategy and age (p<0.001), household size (p<0.001), ethnicity (p<0.001), gender (p=0.005) and interest in healthy eating (p=0.022). Facebook campaigns resulted in the highest absolute numbers of study registrations and randomisations (966 and 584, respectively). Network strategies and Facebook campaigns cost least per randomised participant (NZ$4 and NZ$5, respectively), whereas radio advertising costs most (NZ$179 per participant). Conclusion Internet and social media advertising were the most effective and least costly approaches to recruiting participants to a smartphone-delivered trial. These approaches also reached diverse ethnic groups. However, more culturally appropriate recruitment strategies are likely to be necessary in studies where large numbers of participants from specific ethnic groups are sought. Trial registration ACTRN12614000644662; Post-results. PMID:28674144
A feasibility study investigating the acceptability and design of a multicentre randomised controlled trial of needle fasciotomy versus limited fasciectomy for the treatment of Dupuytren's contractures of the fingers (HAND-1): study protocol for a randomised controlled trial.

PubMed

Harrison, Eleanor; Tan, Wei; Mills, Nicola; Karantana, Alexia; Sprange, Kirsty; Duley, Lelia; Elliott, Daisy; Blazeby, Jane; Hollingworth, William; Montgomery, Alan A; Davis, Tim

2017-08-25

Dupuytren's contractures are fibrous cords under the skin of the palm of the hand. The contractures are painless but cause one or more fingers to curl into the palm, resulting in loss of function. Standard treatment within the NHS is surgery to remove (fasciectomy) or divide (fasciotomy) the contractures, and the treatment offered is frequently determined by surgeon preference. This study aims to determine the feasibility of conducting a large, multicentre randomised controlled trial to assess the clinical and cost-effectiveness of needle fasciotomy versus limited fasciectomy for the treatment of Dupuytren's contracture. HAND-1 is a parallel, two-arm, multicentre, randomised feasibility trial. Eligible patients aged 18 years or over who have one or more fingers with a Dupuytren's contracture of more than 30° in the metacarpophalangeal (MCP) and/or proximal interphalangeal (PIP) joints, well-defined cord(s) causing contracture, and have not undergone previous surgery for Dupuytren's on the same hand will be randomised (1:1) to treatment with either needle fasciotomy or limited fasciectomy. Participants will be followed-up for up to 6 months post surgery. Feasibility outcomes include number of patients screened, consented and randomised, adherence with treatment, completion of follow-up and identification of an appropriate patient-reported outcome measure (PROM) to use as primary outcome for a main trial. Embedded qualitative research, incorporating a QuinteT Recruitment Intervention, will focus on understanding and optimising the recruitment process, and exploring patients' experiences of trial participation and the interventions. This study will assess whether a large multicentre trial comparing the clinical and cost-effectiveness of needle fasciotomy and limited fasciectomy for the treatment of Dupuytren's contractures is feasible, and if so will provide data to inform its design and successful conduct. International Standard Registered Clinical/soCial sTudy Number: ISRCTN11164292 . Registered on 28 August 2015.
ImmunoglobuliN in the Treatment of Encephalitis (IgNiTE): protocol for a multicentre randomised controlled trial

PubMed Central

Iro, M A; Sadarangani, M; Absoud, M; Chong, W K; Clark, C A; Easton, A; Gray, V; Kneen, R; Lim, M; Pike, M; Solomon, T; Vincent, A; Willis, L; Pollard, A J

2016-01-01

Introduction Infectious and immune-mediated encephalitides are important but under-recognised causes of morbidity and mortality in childhood, with a 7% death rate and up to 50% morbidity after prolonged follow-up. There is a theoretical basis for ameliorating the immune response with intravenous immunoglobulin (IVIG), which is supported by empirical evidence of a beneficial response following its use in the treatment of viral and autoimmune encephalitis. In immune-mediated encephalitis, IVIG is often used after a delay (by weeks in some cases), while diagnosis is confirmed. Wider use of IVIG in infectious encephalitis and earlier use in immune-mediated encephalitis could improve outcomes for these conditions. We describe the protocol for the first ever randomised control trial of IVIG treatment for children with all-cause encephalitis. Methods and analysis 308 children (6 months to 16 years) with a diagnosis of acute/subacute encephalitis will be recruited in ∼30 UK hospitals and randomised to receive 2 doses (1 g/kg/dose) of either IVIG or matching placebo, in addition to standard treatment. Recruitment will be over a 42-month period and follow-up of each participant will be for 12 months post randomisation. The primary outcome is ‘good recovery’ (score of 2 or lower on the Glasgow Outcome Score Extended—paediatric version), at 12 months after randomisation. Additional secondary neurological measures will be collected at 4–6 weeks after discharge from acute care and at 6 and 12 months after randomisation. Safety, radiological, other autoimmune and tertiary outcomes will also be assessed. Ethics and dissemination This trial has been approved by the UK National Research Ethics committee (South Central—Oxford A; REC 14/SC/1416). Current protocol: V4.0 (10/03/2016). The findings will be presented at national and international meetings and conferences and published in peer-reviewed journals. Trial registration numbers NCT02308982, EudraCT201400299735 and ISRCTN15791925; Pre-results. PMID:27810972
Computational simulation of laboratory-scale volcanic jets

NASA Astrophysics Data System (ADS)

Solovitz, S.; Van Eaton, A. R.; Mastin, L. G.; Herzog, M.

2017-12-01

Volcanic eruptions produce ash clouds that may travel great distances, significantly impacting aviation and communities downwind. Atmospheric hazard forecasting relies partly on numerical models of the flow physics, which incorporate data from eruption observations and analogue laboratory tests. As numerical tools continue to increase in complexity, they must be validated to fine-tune their effectiveness. Since eruptions are relatively infrequent and challenging to observe in great detail, analogue experiments can provide important insights into expected behavior over a wide range of input conditions. Unfortunately, laboratory-scale jets cannot easily attain the high Reynolds numbers ( 109) of natural volcanic eruption columns. Comparisons between the computational models and analogue experiments can help bridge this gap. In this study, we investigate a 3-D volcanic plume model, the Active Tracer High-resolution Atmospheric Model (ATHAM), which has been used to simulate a variety of eruptions. However, it has not been previously validated using laboratory-scale data. We conducted numerical simulations of three flows that we have studied in the laboratory: a vertical jet in a quiescent environment, a vertical jet in horizontal cross flow, and a particle-laden jet. We considered Reynolds numbers from 10,000 to 50,000, jet-to-cross flow velocity ratios of 2 to 10, and particle mass loadings of up to 25% of the exit mass flow rate. Vertical jet simulations produce Gaussian velocity profiles in the near exit region by 3 diameters downstream, matching the mean experimental profiles. Simulations of air entrainment are of the correct order of magnitude, but they show decreasing entrainment with vertical distance from the vent. Cross flow simulations reproduce experimental trajectories for the jet centerline initially, although confinement appears to impact the response later. Particle-laden simulations display minimal variation in concentration profiles between cases with different mass loadings and size distributions, indicating that differences in particle behavior may not be evident at this laboratory scale.
Exogenous glucagon-like peptide-1 attenuates glucose absorption and reduces blood glucose concentration after small intestinal glucose delivery in critical illness.

PubMed

Miller, Asaf; Deane, Adam M; Plummer, Mark P; Cousins, Caroline E; Chapple, Lee-Anne S; Horowitz, Michael; Chapman, Marianne J

2017-03-01

To evaluate the effect of exogenous glucagonlike peptide-1 (GLP-1) on small intestinal glucose absorption and blood glucose concentrations during critical illness. A prospective, blinded, placebo-controlled, cross-over, randomised trial in a mixed medical-surgical adult intensive care unit, with 12 mechanically ventilated critically ill patients, who were suitable for receiving small intestinal nutrient. On consecutive days, in a randomised order, participants received intravenous GLP-1 (1.2 pmol/ kg/min) or placebo (0.9% saline) as a continuous infusion over 270 minutes. After 6 hours of fasting, intravenous infusions of GLP-1 or placebo began at T = -30 min (in which T = time), with the infusion maintained at a constant rate until study completion at T = 240 min. At T = 0 min, a 100 mL bolus of mixed liquid nutrient meal (1 kcal/mL) containing 3 g of 3-O-methyl-D-gluco-pyranose (3-OMG), a marker of glucose absorption, was administered directly into the small intestine, via a post-pyloric catheter, over 6 minutes. Blood samples were taken at regular intervals for the measurement of plasma glucose and 3-OMG concentrations. Intravenous GLP-1 attenuated initial small intestinal glucose absorption (mean area under the curve [AUC] 0-30 for 3-OMG: GLP-1 group, 4.4 mmol/L/min [SEM, 0.9 mmol/L/min] v placebo group, 6.5 mmol/L/min [SEM, 1.0 mmol/L/min]; P = 0.01), overall small intestinal glucose absorption (mean AUC 0-240 for 3-OMG: GLP-1, 68.2 mmol/L/ min [SEM, 4.7 mmol/L/min] v placebo, 77.7 mmol/L/min [SEM, 4.4 mmol/lLmin]; P = 0.02), small intestinal glucose absorption and overall blood glucose concentration (mean AUC 0-240 for blood glucose: GLP-1, 2062 mmol/L/min [SEM, 111 mmol/L/min] v placebo 2328 mmol/L/min [SEM, 145 mmol/L/min]; P = 0.005). Short-term administration of exogenous GLP-1 reduces small intestinal glucose absorption for up to 4 hours during critical illness. This is likely to be an additional mechanism for the glucose-lowering effect of this agent.
Probiotics for preventing gestational diabetes.

PubMed

Barrett, Helen L; Dekker Nitert, Marloes; Conwell, Louise S; Callaway, Leonie K

2014-02-27

Gestational diabetes mellitus (GDM) is associated with a range of adverse pregnancy outcomes for mother and infant. The prevention of GDM using lifestyle interventions has proven difficult. The gut microbiome (the composite of bacteria present in the intestines) influences host inflammatory pathways, glucose and lipid metabolism and, in other settings, alteration of the gut microbiome has been shown to impact on these host responses. Probiotics are one way of altering the gut microbiome but little is known about their use in influencing the metabolic environment of pregnancy. To assess the effects of probiotic supplementation when compared with other methods for the prevention of GDM. We searched the Cochrane Pregnancy and childbirth Group's Trials Register (31 August 2013) and reference lists of the articles of retrieved studies. Randomised and cluster-randomised trials comparing the use of probiotic supplementation with other methods for the prevention of the development of GDM. Cluster-randomised trials were eligible for inclusion but none were identified. Quasi-randomised and cross-over design studies are not eligible for inclusion in this review. Studies presented only as abstracts with no subsequent full report of study results would also have been excluded. Two review authors independently assessed study eligibility, extracted data and assessed risk of bias of included study. Data were checked for accuracy. Eleven reports (relating to five possible trials) were found. We included one study (six trial reports) involving 256 women. Four other studies are ongoing.The included trial consisted of three treatment arms: probiotic with dietary intervention, placebo and dietary intervention, and dietary intervention alone; it was at a low risk of bias. The study reported primary outcomes of a reduction in the rate of gestational diabetes mellitus (risk ratio (RR) 0.38, 95% confidence interval (CI) 0.20 to 0.70), with no statistical difference in the rates of miscarriage/intrauterine fetal death (IUFD)/stillbirth/neonatal death (RR 2.00, 95% CI 0.35 to 11.35). Secondary outcomes reported were a reduction in infant birthweight (mean difference (MD) -127.71 g, 95% CI -251.37 to -4.06) in the probiotic group and no clear evidence of increased risk of preterm delivery (RR 3.27, 95% CI 0.44 to 24.43), or caesarean section rate (RR 1.23, 95% CI 0.65 to 2.32). The primary infant outcomes of rates of macrosomia and large-for-gestational age infants were not reported. The following secondary outcomes were not reported: maternal gestational weight gain, pre-eclampsia, and the long-term diagnosis of diabetes mellitus; infant body composition, shoulder dystocia, admission to neonatal intensive care, jaundice, hypoglycaemia and long-term rates of obesity and diabetes mellitus. One trial has shown a reduction in the rate of GDM when women are randomised to probiotics early in pregnancy but more uncertain evidence of any effect on miscarriage/IUFD/stillbirth/neonatal death. There are no data on macrosomia. At this time, there are insufficient studies to perform a quantitative meta-analysis. Further results are awaited from four ongoing studies.
Free breakfasts in schools: design and conduct of a cluster randomised controlled trial of the Primary School Free Breakfast Initiative in Wales [ISRCTN18336527

PubMed Central

Moore, Laurence; Moore, Graham F; Tapper, Katy; Lynch, Rebecca; Desousa, Carol; Hale, Janine; Roberts, Chris; Murphy, Simon

2007-01-01

Background School-based breakfast provision is increasingly being seen as a means of improving educational performance and dietary behaviour amongst children. Furthermore, recognition is growing that breakfast provision offers potential as a means of addressing social inequalities in these outcomes. At present however, the evidence base on the effectiveness of breakfast provision in bringing about these improvements is limited. Methods/Design This paper describes the research design of a large scale evaluation of the effectiveness of the Welsh Assembly Government's Primary School Free Breakfast Initiative. A cluster randomised trial, with school as the unit of randomisation was used for the outcome evaluation, with a nested qualitative process evaluation. Quantitative outcome measures included dietary habits, attitudes, cognitive function, classroom behaviour, and school attendance. The study recruited 111 primary schools in Wales, of which 56 were randomly assigned to control condition and 55 to intervention. Participants were Year 5 and 6 students (aged 9–11 years) in these schools. Data were collected for all 111 schools at each of three time points: baseline, 4 month and 12 month follow-up. This was achieved through a repeated cross-sectional survey of approximately 4350 students on each of these occasions. Of those students in Year 5 at baseline, 1975 provided data at one or both of the follow-ups, forming a nested cohort. The evaluation also included a nested process evaluation, using questionnaires, semi-structured interviews and case studies with students, school staff, and local authority scheme coordinators as key informants. Discussion An overview of the methods used for the evaluation is presented, providing an example of the feasibility of conducting robust evaluations of policy initiatives using a randomised trial design with nested process evaluation. Details are provided of response rates and the flow of participants. Reflection is offered on methodological issues encountered at various stages through the course of the study, focusing upon issues associated with conducting a randomised trial of a government policy initiative, and with conducting research in school settings. Trial registration Current Controlled Trials ISRCTN18336527 PMID:17888158
Clinical trial design and dissemination: comprehensive analysis of clinicaltrials.gov and PubMed data since 2005.

PubMed

Zwierzyna, Magdalena; Davies, Mark; Hingorani, Aroon D; Hunter, Jackie

2018-06-06

To investigate the distribution, design characteristics, and dissemination of clinical trials by funding organisation and medical specialty. Cross sectional descriptive analysis. Trial protocol information from clinicaltrials.gov, metadata of journal articles in which trial results were published (PubMed), and quality metrics of associated journals from SCImago Journal and Country Rank database. All 45 620 clinical trials evaluating small molecule therapeutics, biological drugs, adjuvants, and vaccines, completed after January 2006 and before July 2015, including randomised controlled trials and non-randomised studies across all clinical phases. Industry was more likely than non-profit funders to fund large international randomised controlled trials, although methodological differences have been decreasing with time. Among 27 835 completed efficacy trials (phase II-IV), 15 084 (54.2%) had disclosed their findings publicly. Industry was more likely than non-profit trial funders to disseminate trial results (59.3% (10 444/17 627) v 45.3% (4555/10 066)), and large drug companies had higher disclosure rates than small ones (66.7% (7681/11 508) v 45.2% (2763/6119)). Trials funded by the National Institutes of Health (NIH) were disseminated more often than those of other non-profit institutions (60.0% (1451/2417) v 40.6% (3104/7649)). Results of studies funded by large drug companies and NIH were more likely to appear on clinicaltrials.gov than were those from non-profit funders, which were published mainly as journal articles. Trials reporting the use of randomisation were more likely than non-randomised studies to be published in a journal article (6895/19 711 (34.9%) v 1408/7748 (18.2%)), and journal publication rates varied across disease areas, ranging from 42% for autoimmune diseases to 20% for oncology. Trial design and dissemination of results vary substantially depending on the type and size of funding institution as well as the disease area under study. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Free breakfasts in schools: design and conduct of a cluster randomised controlled trial of the Primary School Free Breakfast Initiative in Wales [ISRCTN18336527].

PubMed

Moore, Laurence; Moore, Graham F; Tapper, Katy; Lynch, Rebecca; Desousa, Carol; Hale, Janine; Roberts, Chris; Murphy, Simon

2007-09-21

School-based breakfast provision is increasingly being seen as a means of improving educational performance and dietary behaviour amongst children. Furthermore, recognition is growing that breakfast provision offers potential as a means of addressing social inequalities in these outcomes. At present however, the evidence base on the effectiveness of breakfast provision in bringing about these improvements is limited. This paper describes the research design of a large scale evaluation of the effectiveness of the Welsh Assembly Government's Primary School Free Breakfast Initiative. A cluster randomised trial, with school as the unit of randomisation was used for the outcome evaluation, with a nested qualitative process evaluation. Quantitative outcome measures included dietary habits, attitudes, cognitive function, classroom behaviour, and school attendance. The study recruited 111 primary schools in Wales, of which 56 were randomly assigned to control condition and 55 to intervention. Participants were Year 5 and 6 students (aged 9-11 years) in these schools. Data were collected for all 111 schools at each of three time points: baseline, 4 month and 12 month follow-up. This was achieved through a repeated cross-sectional survey of approximately 4350 students on each of these occasions. Of those students in Year 5 at baseline, 1975 provided data at one or both of the follow-ups, forming a nested cohort. The evaluation also included a nested process evaluation, using questionnaires, semi-structured interviews and case studies with students, school staff, and local authority scheme coordinators as key informants. An overview of the methods used for the evaluation is presented, providing an example of the feasibility of conducting robust evaluations of policy initiatives using a randomised trial design with nested process evaluation. Details are provided of response rates and the flow of participants. Reflection is offered on methodological issues encountered at various stages through the course of the study, focusing upon issues associated with conducting a randomised trial of a government policy initiative, and with conducting research in school settings.
The evaluation of enhanced feedback interventions to reduce unnecessary blood transfusions (AFFINITIE): protocol for two linked cluster randomised factorial controlled trials.

PubMed

Hartley, Suzanne; Foy, Robbie; Walwyn, Rebecca E A; Cicero, Robert; Farrin, Amanda J; Francis, Jill J; Lorencatto, Fabiana; Gould, Natalie J; Grant-Casey, John; Grimshaw, Jeremy M; Glidewell, Liz; Michie, Susan; Morris, Stephen; Stanworth, Simon J

2017-07-03

Blood for transfusion is a frequently used clinical intervention, and is also a costly and limited resource with risks. Many transfusions are given to stable and non-bleeding patients despite no clear evidence of benefit from clinical studies. Audit and feedback (A&F) is widely used to improve the quality of healthcare, including appropriate use of blood. However, its effects are often inconsistent, indicating the need for coordinated research including more head-to-head trials comparing different ways of delivering feedback. A programmatic series of research projects, termed the 'Audit and Feedback INterventions to Increase evidence-based Transfusion practIcE' (AFFINITIE) programme, aims to test different ways of developing and delivering feedback within an existing national audit structure. The evaluation will comprise two linked 2×2 factorial, cross-sectional cluster-randomised controlled trials. Each trial will estimate the effects of two feedback interventions, 'enhanced content' and 'enhanced follow-on support', designed in earlier stages of the AFFINITIE programme, compared to current practice. The interventions will be embedded within two rounds of the UK National Comparative Audit of Blood Transfusion (NCABT) focusing on patient blood management in surgery and use of blood transfusions in patients with haematological malignancies. The unit of randomisation will be National Health Service (NHS) trust or health board. Clusters providing care relevant to the audit topics will be randomised following each baseline audit (separately for each trial), with stratification for size (volume of blood transfusions) and region (Regional Transfusion Committee). The primary outcome for each topic will be the proportion of patients receiving a transfusion coded as unnecessary. For each audit topic a linked, mixed-method fidelity assessment and cost-effectiveness analysis will be conducted in parallel to the trial. AFFINITIE involves a series of studies to explore how A&F may be refined to change practice including two cluster randomised trials linked to national audits of transfusion practice. The methodology represents a step-wise increment in study design to more fully evaluate the effects of two enhanced feedback interventions on patient- and trust-level clinical, cost, safety and process outcomes. http://www.isrctn.com/ISRCTN15490813.
Two-Photon Absorption Properties of Gold Fluorescent Protein: A Combined Molecular Dynamics and Quantum Chemistry Study.

PubMed

Şimşek, Yusuf; Brown, Alex

2018-06-07

Molecular dynamics (MD) simulations were carried out to obtain the conformational changes of the chromophore in the gold fluorescent protein (PDB ID: 1OXF ). To obtain two-photon absorption (TPA) cross-sections, time dependent density functional theory (TD-DFT) computations were performed for chromophore geometries sampled along the trajectory. The TD-DFT computations used the CAM-B3LYP functional and 6-31+G(d) basis set. Results showed that two dihedral angles change remarkably over the simulation time. TPA cross-sections were found to average 13.82 GM for the excitation to S 1 computed from the equilibrium geometries; however, extending the structures with a water molecule and GLU residue, which make H bonds with the chromophore molecule, increased excitation energies and TPA cross-sections significantly. Besides the effects of the surrounding residues and the dihedrals on the spectroscopic properties, some bond lengths affected the excitation energies and the TPA cross-sections significantly (up to ±25-30%), while the effects of the bond angles were smaller (±5%). Overall the present results provide insight into the effects of the conformational flexibility on TPA (with gold fluorescent protein as a specific example) and suggest that further experimental measurements of TPA for the gold fluorescent protein should be undertaken.
Driving Chemical Reactions in Plasmonic Nanogaps with Electrohydrodynamic Flow.

PubMed

Thrift, William J; Nguyen, Cuong Q; Darvishzadeh-Varcheie, Mahsa; Zare, Siavash; Sharac, Nicholas; Sanderson, Robert N; Dupper, Torin J; Hochbaum, Allon I; Capolino, Filippo; Abdolhosseini Qomi, Mohammad Javad; Ragan, Regina

2017-11-28

Nanoparticles from colloidal solution-with controlled composition, size, and shape-serve as excellent building blocks for plasmonic devices and metasurfaces. However, understanding hierarchical driving forces affecting the geometry of oligomers and interparticle gap spacings is still needed to fabricate high-density architectures over large areas. Here, electrohydrodynamic (EHD) flow is used as a long-range driving force to enable carbodiimide cross-linking between nanospheres and produces oligomers exhibiting sub-nanometer gap spacing over mm 2 areas. Anhydride linkers between nanospheres are observed via surface-enhanced Raman scattering (SERS) spectroscopy. The anhydride linkers are cleavable via nucleophilic substitution and enable placement of nucleophilic molecules in electromagnetic hotspots. Atomistic simulations elucidate that the transient attractive force provided by EHD flow is needed to provide a sufficient residence time for anhydride cross-linking to overcome slow reaction kinetics. This synergistic analysis shows assembly involves an interplay between long-range driving forces increasing nanoparticle-nanoparticle interactions and probability that ligands are in proximity to overcome activation energy barriers associated with short-range chemical reactions. Absorption spectroscopy and electromagnetic full-wave simulations show that variations in nanogap spacing have a greater influence on optical response than variations in close-packed oligomer geometry. The EHD flow-anhydride cross-linking assembly method enables close-packed oligomers with uniform gap spacings that produce uniform SERS enhancement factors. These results demonstrate the efficacy of colloidal driving forces to selectively enable chemical reactions leading to future assembly platforms for large-area nanodevices.
Beyond total treatment effects in randomised controlled trials: Baseline measurement of intermediate outcomes needed to reduce confounding in mediation investigations.

PubMed

Landau, Sabine; Emsley, Richard; Dunn, Graham

2018-06-01

Random allocation avoids confounding bias when estimating the average treatment effect. For continuous outcomes measured at post-treatment as well as prior to randomisation (baseline), analyses based on (A) post-treatment outcome alone, (B) change scores over the treatment phase or (C) conditioning on baseline values (analysis of covariance) provide unbiased estimators of the average treatment effect. The decision to include baseline values of the clinical outcome in the analysis is based on precision arguments, with analysis of covariance known to be most precise. Investigators increasingly carry out explanatory analyses to decompose total treatment effects into components that are mediated by an intermediate continuous outcome and a non-mediated part. Traditional mediation analysis might be performed based on (A) post-treatment values of the intermediate and clinical outcomes alone, (B) respective change scores or (C) conditioning on baseline measures of both intermediate and clinical outcomes. Using causal diagrams and Monte Carlo simulation, we investigated the performance of the three competing mediation approaches. We considered a data generating model that included three possible confounding processes involving baseline variables: The first two processes modelled baseline measures of the clinical variable or the intermediate variable as common causes of post-treatment measures of these two variables. The third process allowed the two baseline variables themselves to be correlated due to past common causes. We compared the analysis models implied by the competing mediation approaches with this data generating model to hypothesise likely biases in estimators, and tested these in a simulation study. We applied the methods to a randomised trial of pragmatic rehabilitation in patients with chronic fatigue syndrome, which examined the role of limiting activities as a mediator. Estimates of causal mediation effects derived by approach (A) will be biased if one of the three processes involving baseline measures of intermediate or clinical outcomes is operating. Necessary assumptions for the change score approach (B) to provide unbiased estimates under either process include the independence of baseline measures and change scores of the intermediate variable. Finally, estimates provided by the analysis of covariance approach (C) were found to be unbiased under all the three processes considered here. When applied to the example, there was evidence of mediation under all methods but the estimate of the indirect effect depended on the approach used with the proportion mediated varying from 57% to 86%. Trialists planning mediation analyses should measure baseline values of putative mediators as well as of continuous clinical outcomes. An analysis of covariance approach is recommended to avoid potential biases due to confounding processes involving baseline measures of intermediate or clinical outcomes, and not simply for increased precision.
Clinical and economic evaluation of laparoscopic surgery compared with medical management for gastro-oesophageal reflux disease: 5-year follow-up of multicentre randomised trial (the REFLUX trial).

PubMed

Grant, A M; Boachie, C; Cotton, S C; Faria, R; Bojke, L; Epstein, D M; Ramsay, C R; Corbacho, B; Sculpher, M; Krukowski, Z H; Heading, R C; Campbell, M K

2013-06-01

Despite promising evidence that laparoscopic fundoplication provides better short-term relief of gastro-oesophageal reflux disease (GORD) than continued medical management, uncertainty remains about whether benefits are sustained and outweigh risks. To evaluate the long-term clinical effectiveness, cost-effectiveness and safety of laparoscopic surgery among people with GORD requiring long-term medication and suitable for both surgical and medical management. Five-year follow-up of a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. Cost-effectiveness was assessed alongside the trial using a NHS perspective for costs and expressing health outcomes in terms of quality-adjusted life-years (QALYs). Follow-up was by annual postal questionnaire and selective hospital case notes review; initial recruitment in 21 UK hospitals. Questionnaire responders among the 810 original participants. At entry, all had documented evidence of GORD and symptoms for > 12 months. Questionnaire response rates (years 1-5) were from 89.5% to 68.9%. Three hundred and fifty-seven participants were recruited to the randomised comparison (178 randomised to surgical management and 179 randomised to continued medical management) and 453 to the preference groups (261 surgical management and 192 medical management). The surgeon chose the type of fundoplication. Primary: disease-specific outcome measure (the REFLUX questionnaire); secondary: Short Form questionnaire-36 items (SF-36), European Quality of Life-5 Dimensions (EQ-5D), NHS resource use, reflux medication, complications. The randomised groups were well balanced. By 5 years, 63% in the randomised surgical group and 13% in the randomised medical management group had received a total or partial wrap fundoplication (85% and 3% in the preference groups), with few perioperative complications and no associated deaths. At 1 year (and 5 years) after surgery, 36% (41%) in the randomised surgical group - 15% (26%) of those who had surgery - were taking proton pump inhibitor medication compared with 87% (82%) in the randomised medical group. At each year, differences in the REFLUX score significantly favoured the randomised surgical group (a third of a SD; p< 0.01 at 5 years). SF-36 and EQ-5D scores also favoured surgery, but differences attenuated over time and were generally not statistically significant at 5 years. The worse the symptoms at trial entry, the larger the benefit observed after surgery. Those randomised to medical management who subsequently had surgery had low baseline scores that markedly improved after surgery. Following fundoplication, 3% had surgical treatment for a complication and 4% had subsequent reflux-related operations - most often revision of the wrap. Dysphagia, flatulence and inability to vomit were similar in the two randomised groups. The economic analysis indicated that surgery was the more cost-effective option for this patient group. The incremental cost-effectiveness ratio for surgery in the base case was £7028 per additional QALY; these findings were robust to changes in approaches and assumptions. The probability of surgery being cost-effective at a threshold of £20,000 per additional QALY was > 0.80 for all analyses. After 5 years, laparoscopic fundoplication continues to provide better relief of GORD symptoms with associated improved health-related quality of life. Complications of surgery were uncommon. Despite being initially more costly, a surgical policy is highly likely to be cost-effective. Current Controlled Trials ISRCTN15517081. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 22. See the HTA programme website for further project information.
Simulation of vertical dynamic vehicle-track interaction in a railway crossing using Green's functions

NASA Astrophysics Data System (ADS)

Li, X.; Torstensson, P. T.; Nielsen, J. C. O.

2017-12-01

Vertical dynamic vehicle-track interaction in the through route of a railway crossing is simulated in the time domain based on a Green's function approach for the track in combination with an implementation of Kalker's variational method to solve the non-Hertzian, and potentially multiple, wheel-rail contact. The track is described by a linear, three-dimensional and non-periodic finite element model of a railway turnout accounting for the variations in rail cross-sections and sleeper lengths, and including baseplates and resilient elements. To reduce calculation time due to the complexity of the track model, involving a large number of elements and degrees-of-freedom, a complex-valued modal superposition with a truncated mode set is applied before the impulse response functions are calculated at various positions along the crossing panel. The variation in three-dimensional contact geometry of the crossing and wheel is described by linear surface elements. In each time step of the contact detection algorithm, the lateral position of the wheelset centre is prescribed but the contact positions on wheel and rail are not, allowing for an accurate prediction of the wheel transition between wing rail and crossing rail. The method is demonstrated by calculating the wheel-rail impact load and contact stress distribution for a nominal S1002 wheel profile passing over a nominal crossing geometry. A parameter study is performed to determine the influence of vehicle speed, rail pad stiffness, lateral wheelset position and wheel profile on the impact load generated at the crossing. It is shown that the magnitude of the impact load is more influenced the wheel-rail contact geometry than by the selection of rail pad stiffness.
Using Kokkos for Performant Cross-Platform Acceleration of Liquid Rocket Simulations

DTIC Science & Technology

2017-05-08

NUMBER (Include area code) 08 May 2017 Briefing Charts 05 April 2017 - 08 May 2017 Using Kokkos for Performant Cross-Platform Acceleration of Liquid ...ERC Incorporated RQRC AFRL-West Using Kokkos for Performant Cross-Platform Acceleration of Liquid Rocket Simulations 2DISTRIBUTION A: Approved for... Liquid Rocket Combustion Simulation SPACE simulation of rotating detonation engine (courtesy of Dr. Christopher Lietz) 3DISTRIBUTION A: Approved
[Trans-Cultural Prevention of Alcohol-Related Disorders in Elderly Immigrants].

PubMed

Bermejo, I; Frank, F

2015-09-01

In migrants alcohol-related problems increase with increasing age. This group, in particular, is hardly reached by alcohol-specific care offers. Thus our project aimed at the identification of target group-specific barriers to health-care use by means of a cross-sectional study (n=435). Based on these results a trans-cultural concept for alcohol prevention among elderly migrants was developed and evaluated in a cluster-randomised controlled trial (n=176). © Georg Thieme Verlag KG Stuttgart · New York.
Birth preference in women undergoing treatment for childbirth fear: A randomised controlled trial.

PubMed

Larsson, Birgitta; Karlström, Annika; Rubertsson, Christine; Ternström, Elin; Ekdahl, Johanna; Segebladh, Birgitta; Hildingsson, Ingegerd

2017-12-01

Childbirth fear is the most common underlying reason for requesting a caesarean section without medical reason. The aim of this randomised controlled study was to investigate birth preferences in women undergoing treatment for childbirth fear, and to investigate birth experience and satisfaction with the allocated treatment. Pregnant women classified with childbirth fear (≥60 on the Fear Of Birth Scale) (n=258) were recruited at one university hospital and two regional hospitals over one year. The participants were randomised (1:1) to intervention (Internet-based Cognitive Behaviour Therapy (ICBT)) (n=127) or standard care (face-to-face counselling) (n=131). Data were collected by questionnaires in pregnancy week 20-25 (baseline), week 36 and two months after birth. Caesarean section preference decreased from 34% to 12% in the ICBT group and from 24% to 20% in the counselling group. Two months after birth, the preference for caesarean increased to 20% in the ICBT group and to 29% in the counselling group, and there was no statistically significant change over time. Women in the ICBT group were less satisfied with the treatment (OR 4.5). The treatment had no impact on or worsened their childbirth fear (OR 5.5). There were no differences between the groups regarding birth experience. Women's birth preferences fluctuated over the course of pregnancy and after birth regardless of treatment method. Women felt their fear was reduced and were more satisfied with face-to-face counselling compared to ICBT. A higher percentage were lost to follow-up in ICBT group suggesting a need for further research. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.
Improving non-technical skills (teamwork) in post-partum haemorrhage: A grouped randomised trial.

PubMed

Letchworth, Pippa M; Duffy, Shane P; Phillips, Dan

2017-10-01

To determine the effect of a decision support technology on teamwork and associated non-technical (NTS) and technical skills when teams manage post-partum haemorrhage (PPH) in the simulated environment. Multidisciplinary (MDT) maternity teams were taught how to manage post partum haemorrhage. They were randomised to the intervention: using a decision support mobile digital platform or a control group. Each team managed a post-partum simulation, which was recorded and reviewed by assessors. Primary outcome measures to assess teams NTS were the validated Global Assessment of Obstetric Team Performance (GAOTP) and Clinical Teamwork Scale (CTS). Secondary outcome measures were the 'friends and family test', technical skills, and the System Usability Scale (SUS). Sample size estimation was calculated by using 80% power 5% significance two tailed test (p1=85% p2=40%) n=34. 38 teams from August 2014-February 2016, were recruited, technical issues with failure of recording equipment meant 4 teams were excluded from teamwork analysis (1 intervention 3 control). Teamwork improved across all domains with the intervention (using a decision support mobile digital platform) p <0.01. CTS improved between 6.7-16.8% (average 14.2%) and GAOTP between 8.6-17.1% (average 13.5%) for all domains. Using the control group as baseline, the intervention improved teamwork by 25% using CTS and 22% using GAOTP. Fewer technical skills were missed with the intervention (p<0.01). There was no statistical difference in the time technical skills were achieved. Assessors were more likely to recommend intervention teams 87.5% (77/88) than control teams 63.6% (56/88) p<0.01 to their friends or family. The SUS was 'Good' (69) becoming excellently 'Usable' (81.6) over the study period. We report a decision support system, which improved NTS when managing PPH. Lack of teamwork is often cited as the cause of failures in care and we report a usable technology that assists with and improves teamwork during an emergency. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of portable video media vs standard verbal communication in the urological consent process: a multicentre, randomised controlled, crossover trial.

PubMed

Winter, Matthew; Kam, Jonathan; Nalavenkata, Sunny; Hardy, Ellen; Handmer, Marcus; Ainsworth, Hannah; Lee, Wai Gin; Louie-Johnsun, Mark

2016-11-01

To determine if portable video media (PVM) improves patient's knowledge and satisfaction acquired during the consent process for cystoscopy and insertion of a ureteric stent compared to standard verbal communication (SVC), as informed consent is a crucial component of patient care and PVM is an emerging technology that may help improve the consent process. In this multi-centre randomised controlled crossover trial, patients requiring cystoscopy and stent insertion were recruited from two major teaching hospitals in Australia over a 15-month period (July 2014-December 2015). Patient information delivery was via PVM and SVC. The PVM consisted of an audio-visual presentation with cartoon animation presented on an iPad. Patient satisfaction was assessed using the validated Client Satisfaction Questionnaire 8 (CSQ-8; maximum score 32) and knowledge was tested using a true/false questionnaire (maximum score 28). Questionnaires were completed after first intervention and after crossover. Scores were analysed using the independent samples t-test and Wilcoxon signed-rank test for the crossover analysis. In all, 88 patients were recruited. A significant 3.1 point (15.5%) increase in understanding was demonstrable favouring the use of PVM (P < 0.001). There was no difference in patient satisfaction between the groups as judged by the CSQ-8. A significant 3.6 point (17.8%) increase in knowledge score was seen when the SVC group were crossed over to the PVM arm. A total of 80.7% of patients preferred PVM and 19.3% preferred SVC. Limitations include the lack of a validated questionnaire to test knowledge acquired from the interventions. This study demonstrates patients' preference towards PVM in the urological consent process of cystoscopy and ureteric stent insertion. PVM improves patient's understanding compared with SVC and is a more effective means of content delivery to patients in terms of overall preference and knowledge gained during the consent process. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.
Numerical analysis of the dynamic interaction between wheel set and turnout crossing using the explicit finite element method

NASA Astrophysics Data System (ADS)

Xin, L.; Markine, V. L.; Shevtsov, I. Y.

2016-03-01

A three-dimensional (3-D) explicit dynamic finite element (FE) model is developed to simulate the impact of the wheel on the crossing nose. The model consists of a wheel set moving over the turnout crossing. Realistic wheel, wing rail and crossing geometries have been used in the model. Using this model the dynamic responses of the system such as the contact forces between the wheel and the crossing, crossing nose displacements and accelerations, stresses in rail material as well as in sleepers and ballast can be obtained. Detailed analysis of the wheel set and crossing interaction using the local contact stress state in the rail is possible as well, which provides a good basis for prediction of the long-term behaviour of the crossing (fatigue analysis). In order to tune and validate the FE model field measurements conducted on several turnouts in the railway network in the Netherlands are used here. The parametric study including variations of the crossing nose geometries performed here demonstrates the capabilities of the developed model. The results of the validation and parametric study are presented and discussed.
Assessing self-care and social function using a computer adaptive testing version of the pediatric evaluation of disability inventory.

PubMed

Coster, Wendy J; Haley, Stephen M; Ni, Pengsheng; Dumas, Helene M; Fragala-Pinkham, Maria A

2008-04-01

To examine score agreement, validity, precision, and response burden of a prototype computer adaptive testing (CAT) version of the self-care and social function scales of the Pediatric Evaluation of Disability Inventory compared with the full-length version of these scales. Computer simulation analysis of cross-sectional and longitudinal retrospective data; cross-sectional prospective study. Pediatric rehabilitation hospital, including inpatient acute rehabilitation, day school program, outpatient clinics; community-based day care, preschool, and children's homes. Children with disabilities (n=469) and 412 children with no disabilities (analytic sample); 38 children with disabilities and 35 children without disabilities (cross-validation sample). Not applicable. Summary scores from prototype CAT applications of each scale using 15-, 10-, and 5-item stopping rules; scores from the full-length self-care and social function scales; time (in seconds) to complete assessments and respondent ratings of burden. Scores from both computer simulations and field administration of the prototype CATs were highly consistent with scores from full-length administration (r range, .94-.99). Using computer simulation of retrospective data, discriminant validity, and sensitivity to change of the CATs closely approximated that of the full-length scales, especially when the 15- and 10-item stopping rules were applied. In the cross-validation study the time to administer both CATs was 4 minutes, compared with over 16 minutes to complete the full-length scales. Self-care and social function score estimates from CAT administration are highly comparable with those obtained from full-length scale administration, with small losses in validity and precision and substantial decreases in administration time.
Recovering the colour-dependent albedo of exoplanets with high-resolution spectroscopy: from ESPRESSO to the ELT.

NASA Astrophysics Data System (ADS)

Martins, J. H. C.; Figueira, P.; Santos, N. C.; Melo, C.; Garcia Muñoz, A.; Faria, J.; Pepe, F.; Lovis, C.

2018-05-01

The characterization of planetary atmospheres is a daunting task, pushing current observing facilities to their limits. The next generation of high-resolution spectrographs mounted on large telescopes - such as ESPRESSO@VLT and HIRES@ELT - will allow us to probe and characterize exoplanetary atmospheres in greater detail than possible to this point. We present a method that permits the recovery of the colour-dependent reflectivity of exoplanets from high-resolution spectroscopic observations. Determining the wavelength-dependent albedo will provide insight into the chemical properties and weather of the exoplanet atmospheres. For this work, we simulated ESPRESSO@VLT and HIRES@ELT high-resolution observations of known planetary systems with several albedo configurations. We demonstrate how the cross correlation technique applied to theses simulated observations can be used to successfully recover the geometric albedo of exoplanets over a range of wavelengths. In all cases, we were able to recover the wavelength dependent albedo of the simulated exoplanets and distinguish between several atmospheric models representing different atmospheric configurations. In brief, we demonstrate that the cross correlation technique allows for the recovery of exoplanetary albedo functions from optical observations with the next generation of high-resolution spectrographs that will be mounted on large telescopes with reasonable exposure times. Its recovery will permit the characterization of exoplanetary atmospheres in terms of composition and dynamics and consolidates the cross correlation technique as a powerful tool for exoplanet characterization.
Quantitative EEG analysis using error reduction ratio-causality test; validation on simulated and real EEG data.

PubMed

Sarrigiannis, Ptolemaios G; Zhao, Yifan; Wei, Hua-Liang; Billings, Stephen A; Fotheringham, Jayne; Hadjivassiliou, Marios

2014-01-01

To introduce a new method of quantitative EEG analysis in the time domain, the error reduction ratio (ERR)-causality test. To compare performance against cross-correlation and coherence with phase measures. A simulation example was used as a gold standard to assess the performance of ERR-causality, against cross-correlation and coherence. The methods were then applied to real EEG data. Analysis of both simulated and real EEG data demonstrates that ERR-causality successfully detects dynamically evolving changes between two signals, with very high time resolution, dependent on the sampling rate of the data. Our method can properly detect both linear and non-linear effects, encountered during analysis of focal and generalised seizures. We introduce a new quantitative EEG method of analysis. It detects real time levels of synchronisation in the linear and non-linear domains. It computes directionality of information flow with corresponding time lags. This novel dynamic real time EEG signal analysis unveils hidden neural network interactions with a very high time resolution. These interactions cannot be adequately resolved by the traditional methods of coherence and cross-correlation, which provide limited results in the presence of non-linear effects and lack fidelity for changes appearing over small periods of time. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
[Dexpanthenol nasal spray in comparison to dexpanthenol nasal ointment. A prospective, randomised, open, cross-over study to compare nasal mucociliary clearance].

PubMed

Verse, T; Klöcker, N; Riedel, F; Pirsig, W; Scheithauer, M O

2004-07-01

Recent technical developments in metered pump systems allow the production and use of preservative-free nasal products. The aim of the current study is to compare the tolerability of a preservative-free dexpanthenol (5%) nasal spray with that of the established dexpanthenol (5%) nasal ointment, also without preservatives. The main outcome measure was in vivo mucociliary clearance. Mucociliary clearance was assessed by saccharin migration time in 20 volunteers. Wash-out phases were 7 days and the spray or ointment was always applied 20 min before the saccharin test. The study was designed to test for non-inferiority. Saccharin migration time was slightly longer after ointment administration, however, these were not significantly different to nasal spray. The saccharin migration time showed a significant correlation with the age of the volunteers. The upper confidence limit of dexpanthenol nasal spray was markedly less than that of the ointment. Therefore, dexpanthenol nasal spray is at least equal to if not better than dexpanthenol nasal ointment. Due to its ease of administration, preservative-free dexpanthenol nasal spray offers a valuable therapeutic alternative.
Stakeholders' views on the routine use of n-of-1 trials to improve clinical care and to make resource allocation decisions for drug use.

PubMed

Nikles, Jane; Mitchell, Geoffrey K; Clavarino, Alexandra; Yelland, Michael J; Del Mar, Christopher B

2010-03-01

N-of-1 trials are empirical formal tests using a within-patient randomised, double-blind, cross-over comparison of drug and placebo (or another drug), which we adapted to study individual patients' responses as a clinical tool to guide clinical management. We administered semi-structured interviews to gauge stakeholder perspectives on the possibility of using routine n-of-1 trials for this purpose. Stakeholders included government and non-government health care sector, and patient, clinician and consumer, organisations. Stakeholders supported more widespread implementation of n-of-1 trials, in a targeted fashion, with some caveats. Barriers to their widespread implementation included constraints on doctors' time, doctors' acceptance, drug company acceptance, patient willingness, and cost. Strategies for overcoming barriers included conditional Pharmaceutical Benefits Scheme listing if cost-effective. There was little consensus on which model of n-of-1 trial implementation would be most effective. We discuss different approaches to addressing the several concerns raised to enable widespread introduction of n-of-1 trials into routine clinical practice as a decision tool.
Studies of a new multi-layer compression bandage for the treatment of venous ulceration.

PubMed

Scriven, J M; Bello, M; Taylor, L E; Wood, A J; London, N J

2000-03-01

This study aimed to develop an alternative graduated compression bandage for the treatment of venous leg ulcers. Alternative bandage components were identified and assessed for optimal performance as a graduated multi-layer compression bandage. Subsequently the physical characteristics and clinical efficacy of the optimal bandage combination was prospectively examined. Ten healthy limbs were used to develop the optimal combination and 20 limbs with venous ulceration to compare the physical properties of the two bandage types. Subsequently 42 consecutive ulcerated limbs were prospectively treated to examine the efficacy of the new bandage combination. The new combination produced graduated median (range) sub-bandage pressures (mmHg) as follows: ankle 59 (42-100), calf 36 (27-67) and knee 35 (16-67). Over a seven-day period this combination maintained a comparable level of compression with the Charing Cross system, and achieved an overall healing rate at one year of 88%. The described combination should be brought to the attention of healthcare professionals treating venous ulcers as a possible alternative to other forms of multi-layer graduated compression bandages pending prospective, randomised clinical trials.
Relative bioavailability of rifampicin, isoniazid and ethambutol from a combination tablet vs. concomitant administration of a capsule containing rifampicin and a tablet containing isoniazid and ethambutol.

PubMed

Schall, R; Müller, F O; Duursema, L; Groenewoud, G; Hundt, H K; Middle, M V; Mogilnicka, E M; Swart, K J

1995-11-01

Twenty male volunteers who were slow metabolisers of isoniazid, completed this single-blind, single-dose, randomised, cross-over study to compare the bioavailability of rifampicin (CAS 13292-46-1), isoniazid (CAS 54-85-3) and ethambutol (CAS 1070-11-7) from Myrin tablets (test preparation) with the bioavailability of these drugs from a combination of capsules containing rifampicin and tablets containing isoniazid and ethambutol (reference). There were 2 treatment periods and on clinic days volunteers were given either the reference (300 mig rifampicin plus 200 mg isoniazid and 600 mg ethambutol HCl), or the test preparation (300 mg rifampicin, 150 mg isoniazid and 600 mg ethambutol HCl). Serial blood samples were drawn from the volunteers and rifampicin, isoniazid and ethambutol assays were performed. The results of this study indicate that the test preparation is equivalent to the reference with respect to both the rate and the extent of absorption of rifampicin, isoniazid (after adjustment for the different doses of isoniazid and ethambutol).
Digoxin: use pattern in Estonia and bioavailability of the local market leader.

PubMed

Pähkla, R; Irs, A; Oselin, K; Rootslane, L

1999-10-01

In comparison with neighbouring Scandinavian countries, the use of digoxin in Estonia is high. The present study was carried out to determine the use pattern of digoxin in Estonia and bioavailability of the local market leader preparation in comparison with Lanoxin. Drug use data were evaluated from the annual reports of wholesale companies. For the bioequivalence study, a single-blind cross-over randomised two-way single-dose comparative bioavailability study was performed using 14 healthy volunteers. Digoxin concentrations in serum samples and urine were measured by chemiluminescent competitive immunoassay. The use of digoxin in Estonia has increased by 35% during the period 1994-97. The steady market leader was the local generic drug. No statistically significant differences were found in any pharmacokinetic parameter between the generic preparation and Lanoxin. All parameters showed considerable variability. The total amount of drug excreted was the parameter with lowest inter- individual variation. The present study indicates that the generic digoxin preparation studied is bioequivalent to Lanoxin. The increasing use of digoxin in Estonia is not caused by low bioavailability of the local market leader but by therapeutic traditions.
Accelerating clinical development of HIV vaccine strategies: methodological challenges and considerations in constructing an optimised multi-arm phase I/II trial design.

PubMed

Richert, Laura; Doussau, Adélaïde; Lelièvre, Jean-Daniel; Arnold, Vincent; Rieux, Véronique; Bouakane, Amel; Lévy, Yves; Chêne, Geneviève; Thiébaut, Rodolphe

2014-02-26

Many candidate vaccine strategies against human immunodeficiency virus (HIV) infection are under study, but their clinical development is lengthy and iterative. To accelerate HIV vaccine development optimised trial designs are needed. We propose a randomised multi-arm phase I/II design for early stage development of several vaccine strategies, aiming at rapidly discarding those that are unsafe or non-immunogenic. We explored early stage designs to evaluate both the safety and the immunogenicity of four heterologous prime-boost HIV vaccine strategies in parallel. One of the vaccines used as a prime and boost in the different strategies (vaccine 1) has yet to be tested in humans, thus requiring a phase I safety evaluation. However, its toxicity risk is considered minimal based on data from similar vaccines. We newly adapted a randomised phase II trial by integrating an early safety decision rule, emulating that of a phase I study. We evaluated the operating characteristics of the proposed design in simulation studies with either a fixed-sample frequentist or a continuous Bayesian safety decision rule and projected timelines for the trial. We propose a randomised four-arm phase I/II design with two independent binary endpoints for safety and immunogenicity. Immunogenicity evaluation at trial end is based on a single-stage Fleming design per arm, comparing the observed proportion of responders in an immunogenicity screening assay to an unacceptably low proportion, without direct comparisons between arms. Randomisation limits heterogeneity in volunteer characteristics between arms. To avoid exposure of additional participants to an unsafe vaccine during the vaccine boost phase, an early safety decision rule is imposed on the arm starting with vaccine 1 injections. In simulations of the design with either decision rule, the risks of erroneous conclusions were controlled <15%. Flexibility in trial conduct is greater with the continuous Bayesian rule. A 12-month gain in timelines is expected by this optimised design. Other existing designs such as bivariate or seamless phase I/II designs did not offer a clear-cut alternative. By combining phase I and phase II evaluations in a multi-arm trial, the proposed optimised design allows for accelerating early stage clinical development of HIV vaccine strategies.
Effect of obstetric team training on team performance and medical technical skills: a randomised controlled trial.

PubMed

Fransen, A F; van de Ven, J; Merién, A E R; de Wit-Zuurendonk, L D; Houterman, S; Mol, B W; Oei, S G

2012-10-01

To determine whether obstetric team training in a medical simulation centre improves the team performance and utilisation of appropriate medical technical skills of healthcare professionals. Cluster randomised controlled trial. The Netherlands. The obstetric departments of 24 Dutch hospitals. The obstetric departments were randomly assigned to a 1-day session of multiprofessional team training in a medical simulation centre or to no such training. Team training was given with high-fidelity mannequins by an obstetrician and a communication expert. More than 6 months following training, two unannounced simulated scenarios were carried out in the delivery rooms of all 24 obstetric departments. The scenarios, comprising a case of shoulder dystocia and a case of amniotic fluid embolism, were videotaped. The team performance and utilisation of appropriate medical skills were evaluated by two independent experts. Team performance evaluated with the validated Clinical Teamwork Scale (CTS) and the employment of two specific obstetric procedures for the two clinical scenarios in the simulation (delivery of the baby with shoulder dystocia in the maternal all-fours position and conducting a perimortem caesarean section within 5 minutes for the scenario of amniotic fluid embolism). Seventy-four obstetric teams from 12 hospitals in the intervention group underwent teamwork training between November 2009 and July 2010. The teamwork performance in the training group was significantly better in comparison to the nontraining group (median CTS score: 7.5 versus 6.0, respectively; P = 0.014). The use of the predefined obstetric procedures for the two clinical scenarios was also significantly more frequent in the training group compared with the nontraining group (83 versus 46%, respectively; P = 0.009). Team performance and medical technical skills may be significantly improved after multiprofessional obstetric team training in a medical simulation centre. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.
Improving patient safety through better teamwork: how effective are different methods of simulation debriefing? Protocol for a pragmatic, prospective and randomised study

PubMed Central

Freytag, Julia; Stroben, Fabian; Hautz, Wolf E; Eisenmann, Dorothea; Kämmer, Juliane E

2017-01-01

Introduction Medical errors have an incidence of 9% and may lead to worse patient outcome. Teamwork training has the capacity to significantly reduce medical errors and therefore improve patient outcome. One common framework for teamwork training is crisis resource management, adapted from aviation and usually trained in simulation settings. Debriefing after simulation is thought to be crucial to learning teamwork-related concepts and behaviours but it remains unclear how best to debrief these aspects. Furthermore, teamwork-training sessions and studies examining education effects on undergraduates are rare. The study aims to evaluate the effects of two teamwork-focused debriefings on team performance after an extensive medical student teamwork training. Methods and analyses A prospective experimental study has been designed to compare a well-established three-phase debriefing method (gather–analyse–summarise; the GAS method) to a newly developed and more structured debriefing approach that extends the GAS method with TeamTAG (teamwork techniques analysis grid). TeamTAG is a cognitive aid listing preselected teamwork principles and descriptions of behavioural anchors that serve as observable patterns of teamwork and is supposed to help structure teamwork-focused debriefing. Both debriefing methods will be tested during an emergency room teamwork-training simulation comprising six emergency medicine cases faced by 35 final-year medical students in teams of five. Teams will be randomised into the two debriefing conditions. Team performance during simulation and the number of principles discussed during debriefing will be evaluated. Learning opportunities, helpfulness and feasibility will be rated by participants and instructors. Analyses will include descriptive, inferential and explorative statistics. Ethics and dissemination The study protocol was approved by the institutional office for data protection and the ethics committee of Charité Medical School Berlin and registered under EA2/172/16. All students will participate voluntarily and will sign an informed consent after receiving written and oral information about the study. Results will be published. PMID:28667224
Simulation-based training in flexible fibreoptic intubation: A randomised study.

PubMed

Nilsson, Philip M; Russell, Lene; Ringsted, Charlotte; Hertz, Peter; Konge, Lars

2015-09-01

Flexible fibreoptic intubation (FOI) is a key element in difficult airway management. Training of FOI skills is an important part of the anaesthesiology curriculum. Simulation-based training has been shown to be effective when learning FOI, but the optimal structure of the training is debated. The aspect of dividing the training into segments (part-task training) or assembling into one piece (whole-task training) has not been studied. The aims of this study were to compare the effect of training the motor skills of FOI as part-task training or as whole-task training and to relate the performance levels achieved by the novices to the standard of performance of experienced FOI practitioners. A randomised controlled study. Centre for Clinical Education, University of Copenhagen and the Capital Region of Denmark, between January and April 2013. Twenty-three anaesthesia residents in their first year of training in anaesthesiology with no experience in FOI, and 10 anaesthesia consultants experienced in FOI. The novices to FOI were allocated randomly to receive either part-task or whole-task training of FOI on virtual reality simulators. Procedures were subsequently trained on a manikin and assessed by an experienced anaesthesiologist. The experienced group was assessed in the same manner with no prior simulation-based training. The primary outcome measure was the score of performance on testing FOI skills on a manikin. A positive learning effect was observed in both the part-task training group and the whole-task training group. There was no statistically significant difference in final performance scores of the two novice groups (P = 0.61). Furthermore, both groups of novices were able to improve their skill level significantly by the end of manikin training to levels comparable to the experienced anaesthesiologists. Part-task training did not prove more effective than whole-task training when training novices in FOI skills. FOI is very suitable for simulation-based training and segmentation of the procedure during training is not necessary.
Simulations of Flooding on Pea River and Whitewater Creek in the Vicinity of the Proposed Elba Bypass at Elba, Alabama

USGS Publications Warehouse

Hedgecock, T. Scott

2003-01-01

A two-dimensional finite-element surface-water model was used to study the effects of proposed modifications to the State Highway 203 corridor (proposed Elba Bypass/relocated U.S. Highway 84) on water-surface elevations and flow distributions during flooding in the Pea River and Whitewater Creek Basins at Elba, Coffee County, Alabama. Flooding was first simulated for the March 17, 1990, flood, using the 1990 flood-plain conditions to calibrate the model to match measured data collected by the U.S. Geological Survey and the U.S. Army Corps of Engineers after the flood. After model calibration, the effects of flooding were simulated for four scenarios: (1) floods having the 50- and 100-year recurrence intervals for the existing flood-plain, bridge, highway, and levee conditions; (2) floods having the 50- and 100-year recurrence intervals for the existing flood-plain and levee conditions with the State Highway 203 embankment and bridge removed; (3) floods having the 50- and 100-year recurrence intervals for the existing flood-plain, bridge, and highway conditions with proposed modifications (elevating) to the levee; and (4) floods having the 50- and 100-year recurrence intervals for the proposed conditions reflecting the Elba Bypass and modified levee. The simulation of floodflow for the Pea River and Whitewater Creek flood of March 17, 1990, in the study reach compared closely to flood profile data obtained after the flood. The flood of March 17, 1990, had an estimated peak discharge of 58,000 cubic feet per second at the gage (just below the confluence) and was estimated to be between a 50-year and 100-year flood event. The estimated peak discharge for Pea River and Whitewater Creek was 40,000 and 42,000 cubic feet per second, respectively. Simulation of floodflows for the 50-year flood (51,400 cubic feet per second) at the gage for existing flood-plain, bridge, highway, and levee conditions indicated that about 31 percent of the peak flow was conveyed by the State Highway 203 bridge over Whitewater Creek, approximately 12 percent overtopped the State Highway 203 embankment, and about 57 percent was conveyed by the Pea River flood plain east of State Highway 125. For this simulation, flow from Pea River (2,380 cubic feet per second) overtopped State Highway 125 and crossed over into the Whitewater Creek flood plain north of State Highway 203, creating one common flood plain. The water-surface elevation estimated at the downstream side of the State Highway 203 bridge crossing Whitewater Creek was 202.82 feet. The girders for both the State Highway 203 and U.S. Highway 84 bridges were partially submerged, but U.S. Highway 84 was not overtopped. For the 100-year flood (63,500 cubic feet per second) at the gage, the simulation indicated that about 25 percent of the peak flow was conveyed by the State Highway 203 bridge over Whitewater Creek, approximately 24 percent overtopped the State Highway 203 embankment, and about 51 percent was conveyed by the Pea River flood plain east of State Highway 125. The existing levee adjacent to Whitewater Creek was overtopped by a flow of 3,200 cubic feet per second during the 100-year flood. For this simulation, flow from Pea River (6,710 cubic feet per second) overtopped State Highway 125 and crossed over into the Whitewater Creek flood plain north of State Highway 203. The water-surface elevation estimated at the downstream side of the State Highway 203 bridge crossing Whitewater Creek was 205.60 feet. The girders for both the State Highway 203 and U.S. Highway 84 bridges were partially submerged, and the west end of the U.S. Highway 84 bridge was overtopped. Simulation of floodflows for the 50-year flood at the gage for existing flood-plain and levee conditions, but with the State Highway 203 embankment and bridge removed, yielded a lower water-surface elevation (202.90 feet) upstream of this bridge than that computed for the existing conditions. For the 100-year flood, the simulation indi
Ghrelin for the management of cachexia associated with cancer.

PubMed

Khatib, Mahalaqua Nazli; Shankar, Anuraj H; Kirubakaran, Richard; Gaidhane, Abhay; Gaidhane, Shilpa; Simkhada, Padam; Quazi Syed, Zahiruddin

2018-02-28

Cancer sufferers are amongst the most malnourished of all the patient groups. Studies have shown that ghrelin, a gut hormone can be a potential therapeutic agent for cachexia (wasting syndrome) associated with cancer. A variety of mechanisms of action of ghrelin in people with cancer cachexia have been proposed. However, safety and efficacy of ghrelin for cancer-associated cachexia have not been systematically reviewed. The aim of this review was to assess whether ghrelin is associated with better food intake, body composition and survival than other options for adults with cancer cachexia. To assess the efficacy and safety of ghrelin in improving food intake, body composition and survival in people with cachexia associated with cancer. We searched CENTRAL, MEDLINE and Embase without language restrictions up to July 2017. We also searched for ongoing studies in trials registers, performed handsearching, checked bibliographic references of relevant articles and contacted authors and experts in the field to seek potentially relevant research. We applied no restrictions on language, date, or publication status. We included randomised controlled (parallel-group or cross-over) trials comparing ghrelin (any formulation or route of administration) with placebo or an active comparator in adults (aged 18 years and over) who met any of the international criteria for cancer cachexia. Two review authors independently assessed studies for eligibility. Two review authors then extracted data and assessed the risk of bias for individual studies using standard Cochrane methodology. For dichotomous variables, we planned to calculate risk ratio with 95% confidence intervals (CI) and for continuous data, we planned to calculate mean differences (MD) with 95% CI. We assessed the evidence using GRADE and created 'Summary of findings' tables. We screened 926 individual references and identified three studies that satisfied the inclusion criteria. Fifty-nine participants (37 men and 22 women) aged between 54 and 78 years were randomised initially, 47 participants completed the treatment. One study had a parallel design and two had a cross-over design. The studies included people with a variety of cancers and also differed in the dosage, route of administration, frequency and duration of treatment.One trial, which compared ghrelin with placebo, found that ghrelin improved food intake (very low-quality evidence) and had no adverse events (very low-quality evidence). Due to unavailability of data we were unable to report on comparisons for ghrelin versus no treatment or alternative experimental treatment modalities, or ghrelin in combination with other treatments or ghrelin analogues/ghrelin mimetics/ghrelin potentiators. Two studies compared a higher dose of ghrelin with a lower dose of ghrelin, however due to differences in study designs and great diversity in the treatment provided we did not pool the results. In both trials, food intake did not differ between participants on higher-dose and lower-dose ghrelin. None of the included studies assessed data on body weight. One study reported higher adverse events with a higher dose as compared to a lower dose of ghrelin.All studies were at high risk of attrition bias and bias for size of the study. Risk of bias in other domains was unclear or low.We rated the overall quality of the evidence for primary outcomes (food intake, body weight, adverse events) as very low. We downgraded the quality of the evidence due to lack of data, high or unclear risk of bias of the studies and small study size. There is insufficient evidence to be able to support or refute the use of ghrelin in people with cancer cachexia. Adequately powered randomised controlled trials focusing on evaluation of safety and efficacy of ghrelin in people with cancer cachexia is warranted.
A single spacecraft method to study the spatial profiles inside the magnetopause

NASA Astrophysics Data System (ADS)

Dorville, Nicolas; Belmont, Gerard; Rezeau, Laurence; Aunai, Nicolas; Retino, Alessandro

2013-04-01

Previous magnetopause observations have revealed that the tangential magnetic field often rotates over C-shaped hodograms during the boundary crossing. Using observations of magnetopause crossings by the ESA Cluster mission and a simulation developed at LPP by Nicolas Aunai, we developed a single spacecraft method using the temporal information on the magnetic field in such crossings, complemented by the ion data. We can so obtain a 1D spatial parameter to characterize the depth in the layer and study the structure of the magnetopause as a function of this parameter. This allows using one single spacecraft magnetic data, completed by ion data at large temporal scales, to study the spatial structure of the boundary, and access scales that the particle temporal measurements of the four spacecraft do not permit. To obtain the normal direction and position, we first initialize our computations thanks to the standard MVABC method. Then we use the magnetic field data in the current layer, and suppose it is 1D, rotating in the tangential plane along an ellipse, with an angle variation essentially linear in space, with small sinusoidal perturbations. Making the assumption that the normal velocity of ions is dominated by the motion of the boundary and that the internal structure of the magnetopause is stationary over the duration of a crossing, we can compute the best normal direction and parameters of the model with CIS velocity and FGM magnetic field data, and so derive the spatial position of the spacecraft in the boundary. This method, which has been tested on the simulation data, could be applied successfully on several magnetopause crossings observed by Cluster. It directly gives a thickness and a normal direction, and permits to establish spatial profiles of all the physical quantities inside the boundary. It can be used to better understand the internal structure of the boundary, its physical properties and behavior regarding the flux conservation equations. The obtained results are compared with the results of other methods.
No economic benefit of early knee reconstruction over optional delayed reconstruction for ACL tears: registry enriched randomised controlled trial data.

PubMed

Kiadaliri, Aliasghar A; Englund, Martin; Lohmander, L Stefan; Carlsson, Katarina Steen; Frobell, Richard B

2016-05-01

To analyse 5-year cost-effectiveness of early versus optional delayed acute anterior cruciate ligament (ACL) reconstruction. 121 young, active adults with acute ACL injury to a previously uninjured knee were randomised to early ACL reconstruction (n=62, within 10 weeks of injury) or optional delayed ACL reconstruction (n=59; 30 with ACL reconstruction within 6-55 months); all patients received similar structured rehabilitation. Real life data on health care utilisation and sick leave were obtained from regional and national registers. Costs and quality-adjusted life years (QALYs) were discounted at 3%. Full-analysis set (based on study randomisation) and as-treated analysis (according to actual treatment over 5 years) principles were applied. Mean cost of early ACL reconstruction was €4695 higher than optional delayed ACL reconstruction (p=0.19) and provided an additional 0.13 QALYs (p=0.11). Full-analysis set showed incremental net benefit of early versus optional delayed ACL reconstruction was not statistically significantly different from zero at any level. As-treated analysis showed that costs for rehabilitation alone were €13 650 less than early ACL reconstruction (p<0.001). Results were robust to sensitivity analyses. In young active adults with acute ACL injury, a strategy of early ACL reconstruction did not provide extra economic value over a strategy of optional delayed ACL reconstruction over a 5-year period. Results from this and previous reports of the KANON-trial imply that early identification of individuals who would benefit from either early ACL reconstruction or rehabilitation alone might reduce resource consumption and decrease risk of unnecessary overtreatment. ISRCTN84752559. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Randomised, double blind, placebo controlled trial of intravenous antioxidant (n‐acetylcysteine, selenium, vitamin C) therapy in severe acute pancreatitis

PubMed Central

Siriwardena, Ajith K; Mason, James M; Balachandra, Srinivasan; Bagul, Anil; Galloway, Simon; Formela, Laura; Hardman, Jonathan G; Jamdar, Saurabh

2007-01-01

Background Based on equivocal clinical data, intravenous antioxidant therapy has been used for the treatment of severe acute pancreatitis. To date there is no randomised comparison of this therapy in severe acute pancreatitis. Methods We conducted a randomised, double blind, placebo controlled trial of intravenous antioxidant (n‐acetylcysteine, selenium, vitamin C) therapy in patients with predicted severe acute pancreatitis. Forty‐three patients were enrolled from three hospitals in the Manchester (UK) area over the period June 2001 to November 2004. Randomisation stratified for APACHE‐II score and hospital site, and delivered groups that were similar at baseline. Results Relative serum levels of antioxidants rose while markers of oxidative stress fell in the active treatment group during the course of the trial. However, at 7 days, there was no statistically significant difference in the primary end point, organ dysfunction (antioxidant vs placebo: 32% vs 17%, p = 0.33) or any secondary end point of organ dysfunction or patient outcome. Conclusions This study provides no evidence to justify continued use of n‐acetylcysteine, selenium, vitamin C based antioxidant therapy in severe acute pancreatitis. In the context of any future trial design, careful consideration must be given to the risks raised by the greater trend towards adverse outcome in patients in the treatment arm of this study. PMID:17356040
Bioprosthetic heart valve heterograft biomaterials: structure, mechanical behavior and computational simulation.

PubMed

Sacks, Michael S; Mirnajafi, Ali; Sun, Wei; Schmidt, Paul

2006-11-01

The present review surveys significant developments in the biomechanical characterization and computational simulation of biologically derived chemically cross-linked soft tissues, or 'heterograft' biomaterials, used in replacement bioprosthetic heart valve (BHV). A survey of mechanical characterization techniques, relevant mechanical properties and computational simulation approaches is presented for both the source tissues and cross-linked biomaterials. Since durability remains the critical problem with current bioprostheses, changes with the mechanical behavior with fatigue are also presented. Moreover, given the complex nature of the mechanical properties of heterograft biomaterials it is not surprising that most constitutive (stress-strain) models, historically used to characterize their behavior, were oversimplified. Simulations of BHV function utilizing these models have inevitably been inaccurate. Thus, more recent finite element simulations utilizing nonlinear constitutive models, which achieve greater model fidelity, are reviewed. An important conclusion of this review is the need for accurate constitutive models, rigorously validated with appropriate experimental data, in order that the design benefits of computational models can be realized. Finally, for at least the coming 20 years, BHVs fabricated from heterograft biomaterials will continue to be extensively used, and will probably remain as the dominant valve design. We should thus recognize that rational, scientifically based approaches to BHV biomaterial development and design can lead to significantly improved BHV, over the coming decades, which can potentially impact millions of patients worldwide with heart valve disease.

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