Xiong, Chengjie; Luo, Jingqin; Morris, John C; Bateman, Randall
2018-01-01
Modern clinical trials on Alzheimer disease (AD) focus on the early symptomatic stage or even the preclinical stage. Subtle disease progression at the early stages, however, poses a major challenge in designing such clinical trials. We propose a multivariate mixed model on repeated measures to model the disease progression over time on multiple efficacy outcomes, and derive the optimum weights to combine multiple outcome measures by minimizing the sample sizes to adequately power the clinical trials. A cross-validation simulation study is conducted to assess the accuracy for the estimated weights as well as the improvement in reducing the sample sizes for such trials. The proposed methodology is applied to the multiple cognitive tests from the ongoing observational study of the Dominantly Inherited Alzheimer Network (DIAN) to power future clinical trials in the DIAN with a cognitive endpoint. Our results show that the optimum weights to combine multiple outcome measures can be accurately estimated, and that compared to the individual outcomes, the combined efficacy outcome with these weights significantly reduces the sample size required to adequately power clinical trials. When applied to the clinical trial in the DIAN, the estimated linear combination of six cognitive tests can adequately power the clinical trial. PMID:29546251
Kidney function endpoints in kidney transplant trials: a struggle for power.
Ibrahim, A; Garg, A X; Knoll, G A; Akbari, A; White, C A
2013-03-01
Kidney function endpoints are commonly used in randomized controlled trials (RCTs) in kidney transplantation (KTx). We conducted this study to estimate the proportion of ongoing RCTs with kidney function endpoints in KTx where the proposed sample size is large enough to detect meaningful differences in glomerular filtration rate (GFR) with adequate statistical power. RCTs were retrieved using the key word "kidney transplantation" from the National Institute of Health online clinical trial registry. Included trials had at least one measure of kidney function tracked for at least 1 month after transplant. We determined the proportion of two-arm parallel trials that had sufficient sample sizes to detect a minimum 5, 7.5 and 10 mL/min difference in GFR between arms. Fifty RCTs met inclusion criteria. Only 7% of the trials were above a sample size of 562, the number needed to detect a minimum 5 mL/min difference between the groups should one exist (assumptions: α = 0.05; power = 80%, 10% loss to follow-up, common standard deviation of 20 mL/min). The result increased modestly to 36% of trials when a minimum 10 mL/min difference was considered. Only a minority of ongoing trials have adequate statistical power to detect between-group differences in kidney function using conventional sample size estimating parameters. For this reason, some potentially effective interventions which ultimately could benefit patients may be abandoned from future assessment. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.
Does Ureaplasma spp. cause chronic lung disease of prematurity: Ask the audience?
Maxwell, Nicola C.; Nuttall, Diane; Kotecha, Sailesh
2009-01-01
Ureaplasma has long been implicated in the pathogenesis of both preterm labour and neonatal morbidity, particularly chronic lung disease of prematurity (CLD), but despite numerous studies, reviews and meta-analyses, its exact role remains unclear. Many papers call for a definitive randomised control trial to determine if eradication of pulmonary Ureaplasma decreases the rates of CLD but few address in detail the obstacles to an adequately powered clinical trial. We review the evidence for Ureaplasma as a causative agent in CLD, asking why a randomised control trial has not been performed. We surveyed the opinions of senior neonatologists in the UK on whether they felt that there was sufficient evidence for Ureaplasma either causing or not causing CLD and whether a definitive trial was needed, as well as their views on the design of such a trial. Additionally, we ascertained current practice with respect to Ureaplasma detection in preterm neonates in the UK. There is clear support for an adequately powered randomised controlled clinical trial by senior neonatologists in the UK. There are no reasons why a definitive trial cannot be conducted especially as the appropriate samples, and methods to culture or identify the organism by PCR are already available. PMID:19144476
Revisiting sample size: are big trials the answer?
Lurati Buse, Giovanna A L; Botto, Fernando; Devereaux, P J
2012-07-18
The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.
Design, analysis and presentation of factorial randomised controlled trials
Montgomery, Alan A; Peters, Tim J; Little, Paul
2003-01-01
Background The evaluation of more than one intervention in the same randomised controlled trial can be achieved using a parallel group design. However this requires increased sample size and can be inefficient, especially if there is also interest in considering combinations of the interventions. An alternative may be a factorial trial, where for two interventions participants are allocated to receive neither intervention, one or the other, or both. Factorial trials require special considerations, however, particularly at the design and analysis stages. Discussion Using a 2 × 2 factorial trial as an example, we present a number of issues that should be considered when planning a factorial trial. The main design issue is that of sample size. Factorial trials are most often powered to detect the main effects of interventions, since adequate power to detect plausible interactions requires greatly increased sample sizes. The main analytical issues relate to the investigation of main effects and the interaction between the interventions in appropriate regression models. Presentation of results should reflect the analytical strategy with an emphasis on the principal research questions. We also give an example of how baseline and follow-up data should be presented. Lastly, we discuss the implications of the design, analytical and presentational issues covered. Summary Difficulties in interpreting the results of factorial trials if an influential interaction is observed is the cost of the potential for efficient, simultaneous consideration of two or more interventions. Factorial trials can in principle be designed to have adequate power to detect realistic interactions, and in any case they are the only design that allows such effects to be investigated. PMID:14633287
Friedli, Karin; Almond, Michael; Day, Clara; Chilcot, Joseph; Gane, Maria da Silva; Davenport, Andrew; Guirguis, Ayman; Fineberg, Naomi; Spencer, Benjamin; Wellsted, David; Farrington, Ken
2015-10-26
The prevalence of depression in people receiving haemodialysis is high with estimates varying between 20 and 40 %. There is little research on the effectiveness of antidepressants in dialysis patients with the few clinical trials suffering significant methodological issues. We plan to carry out a study to evaluate the feasibility of conducting a randomised controlled trial in patients on haemodialysis who have diagnosed Major Depressive Disorder. The study has two phases, a screening phase and the randomised controlled trial. Patients will be screened initially with the Beck Depression Inventory to estimate the number of patients who score 16 or above. These patients will be invited to an interview with a psychiatrist who will invite those with a diagnosis of Major Depressive Disorder to take part in the trial. Consenting patients will be randomised to either Sertraline or placebo. Patients will be followed-up for 6 months. Demographic and clinical data will be collected at screening interview, baseline interview and 2 weeks, and every month (up to 6 months) after baseline. The primary outcome is to evaluate the feasibility of conducting a randomised, double blind, placebo pilot trial in haemodialysis patients with depression. Secondary outcomes include estimation of the variability in the outcome measures for the treatment and placebo arms, which will allow for a future adequately powered definitive trial. Analysis will primarily be descriptive, including the number of patients eligible for the trial, drug exposure of Sertraline in haemodialysis patients and the patient experience of participating in this trial. There is an urgent need for this research in the dialysis population because of the dearth of good quality and adequately powered studies. Research with renal patients is particularly difficult as they often have complex medical needs. This research will therefore not only assess the outcome of anti-depressants in haemodialysis patients with depression but also the process of running a randomised controlled trial in this population. Hence, the outputs of this feasibility study will be used to inform the design and methodology of a definitive study, adequately powered to determine the efficacy of anti-depressants in patient on haemodialysis with depression. ISRCTN registry ISRCTN06146268 and EudraCT reference: 2012-000547-27.
Phelps, Geoffrey; Kelcey, Benjamin; Jones, Nathan; Liu, Shuangshuang
2016-10-03
Mathematics professional development is widely offered, typically with the goal of improving teachers' content knowledge, the quality of teaching, and ultimately students' achievement. Recently, new assessments focused on mathematical knowledge for teaching (MKT) have been developed to assist in the evaluation and improvement of mathematics professional development. This study presents empirical estimates of average program change in MKT and its variation with the goal of supporting the design of experimental trials that are adequately powered to detect a specified program effect. The study drew on a large database representing five different assessments of MKT and collectively 326 professional development programs and 9,365 teachers. Results from cross-classified hierarchical growth models found that standardized average change estimates across the five assessments ranged from a low of 0.16 standard deviations (SDs) to a high of 0.26 SDs. Power analyses using the estimated pre- and posttest change estimates indicated that hundreds of teachers are needed to detect changes in knowledge at the lower end of the distribution. Even studies powered to detect effects at the higher end of the distribution will require substantial resources to conduct rigorous experimental trials. Empirical benchmarks that describe average program change and its variation provide a useful preliminary resource for interpreting the relative magnitude of effect sizes associated with professional development programs and for designing adequately powered trials. © The Author(s) 2016.
Ferrante di Ruffano, Lavinia; Dinnes, Jacqueline; Sitch, Alice J; Hyde, Chris; Deeks, Jonathan J
2017-02-24
There is a growing recognition for the need to expand our evidence base for the clinical effectiveness of diagnostic tests. Many international bodies are calling for diagnostic randomized controlled trials to provide the most rigorous evidence of impact to patient health. Although these so-called test-treatment RCTs are very challenging to undertake due to their methodological complexity, they have not been subjected to a systematic appraisal of their methodological quality. The extent to which these trials may be producing biased results therefore remains unknown. We set out to address this issue by conducting a methodological review of published test-treatment trials to determine how often they implement adequate methods to limit bias and safeguard the validity of results. We ascertained all test-treatment RCTs published 2004-2007, indexed in CENTRAL, including RCTs which randomized patients to diagnostic tests and measured patient outcomes after treatment. Tests used for screening, monitoring or prognosis were excluded. We assessed adequacy of sequence generation, allocation concealment and intention-to-treat, appropriateness of primary analyses, blinding and reporting of power calculations, and extracted study characteristics including the primary outcome. One hundred three trials compared 105 control with 119 experimental interventions, and reported 150 primary outcomes. Randomization and allocation concealment were adequate in 57 and 37% of trials. Blinding was uncommon (patients 5%, clinicians 4%, outcome assessors 21%), as was an adequate intention-to-treat analysis (29%). Overall 101 of 103 trials (98%) were at risk of bias, as judged using standard Cochrane criteria. Test-treatment trials are particularly susceptible to attrition and inadequate primary analyses, lack of blinding and under-powering. These weaknesses pose much greater methodological and practical challenges to conducting reliable RCT evaluations of test-treatment strategies than standard treatment interventions. We suggest a cautious approach that first examines whether a test-treatment intervention can accommodate the methodological safeguards necessary to minimize bias, and highlight that test-treatment RCTs require different methods to ensure reliability than standard treatment trials. Please see the companion paper to this article: http://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-016-0286-0 .
Evaluation of Contribution for Voltage Control Ancillary Services Based on Social Surplus
NASA Astrophysics Data System (ADS)
Ueki, Yuji; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun
Reactive power supply plays an important role in active power supply with adequate system voltages. Various pricing mechanism for reactive power supply have been developed and some of them are adopted in some power systems, however they are in a trial stage. The authors also focus on development of a pricing method for reactive power ancillary services. This problem involves two technical issues: rational estimation of the cost associated with reactive power supply and fair and transparent allocation of the estimated cost among the market participants. This paper proposes methods for evaluating the contribution of generators and demands.
Chelation therapy to treat atherosclerosis, particularly in diabetes: Is it time to reconsider?
Lamas, Gervasio A; Ergui, Ian
2016-01-01
Summary Reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes. The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years. These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. PMID:27149141
Is Neurofeedback an Efficacious Treatment for ADHD? A Randomised Controlled Clinical Trial
ERIC Educational Resources Information Center
Gevensleben, Holger; Holl, Birgit; Albrecht, Bjorn; Vogel, Claudia; Schlamp, Dieter; Kratz, Oliver; Studer, Petra; Rothenberger, Aribert; Moll, Gunther H.; Heinrich, Hartmut
2009-01-01
Background: For children with attention deficit/hyperactivity disorder (ADHD), a reduction of inattention, impulsivity and hyperactivity by neurofeedback (NF) has been reported in several studies. But so far, unspecific training effects have not been adequately controlled for andor studies do not provide sufficient statistical power. To overcome…
Bousquet, Philippe J; Calderón, Moisés A; Demoly, Pascal; Larenas, Désirée; Passalacqua, Giovanni; Bachert, Claus; Brozek, Jan; Canonica, G Walter; Casale, Thomas; Fonseca, Joao; Dahl, Ronald; Durham, Stephen R; Merk, Hans; Worm, Margitta; Wahn, Ulrich; Zuberbier, Torsten; Schünemann, Holger J; Bousquet, Jean
2011-01-01
Randomized trials provide evidence to inform treatment decisions. The Consolidated Standards of Reporting Trials (CONSORT) Statement is a set of recommendations for the reporting of trials. We sought to assess the quality of reporting allergen-specific immunotherapy trials according to CONSORT criteria. The reporting of the procedure, randomization, dropouts, strict conduct of intention-to-treat (ITT) analysis, and sample size calculation according to CONSORT were assessed in the 46 subcutaneous and 48 sublingual immunotherapy (SLIT) blind, placebo-controlled randomized trials published between 1996 and 2009 in English. One subcutaneous immunotherapy (2.2%) and 3 SLIT (6.6%) trials met CONSORT Statement criteria. These were used for the registration of sublingual tablets to the European Medicines Agency. In subcutaneous immunotherapy, 16 (35%) studies reported a CONSORT flow chart, and 12 (26%) provided a description of dropouts. Adequate randomization was reported in 9 (35%) studies, and incomplete randomization was reported in 15 (33%). Power analysis was reported in 15 (33%) studies. In SLIT, 20 (42%) studies reported a CONSORT flow chart, and 16 (32%) a description of dropouts. ITT analysis was carried out in 1 (2.2%) SLIT study, and a modified ITT analysis was used in 1 (2.2%) subcutaneous immunotherapy study and 2 (4.4%) SLIT studies. Adequate randomization was reported in 6 (12%) studies, and incomplete randomization was reported in 16 (32%). Power analysis was reported in 15 (27%) studies. As in other areas of medicine, the quality of reporting of most immunotherapy trials is low, and only 4.2% of SLIT randomized controlled trials met all of the criteria of the CONSORT Statement. Use of the CONSORT criteria should be encouraged. Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.
Treatments for somnambulism in adults: assessing the evidence.
Harris, Melanie; Grunstein, Ronald R
2009-08-01
Somnambulism, or sleepwalking, is a parasomnia of non-rapid eye movement (NREM) sleep where movement behaviours usually confined to wakefulness are displayed during sleep. Generally, if sleepwalking is causing distress or danger in spite of safety measures, medical or psychological treatment is indicated. Clinicians will need to assess the evidence for treatment options. MEDLINE, EMBASE, PsycINFO and the Ovid Evidence-Based Medicine Reviews (EBM) multifile databases were searched. No properly powered rigorous controlled trials were found for treatment of sleepwalking in adults. Seven reports described small trials with some kind of control arm, or retrospective case series which included 30 or more patients. With no high quality evidence to underpin recommendations for treatments of somnambulism, full discussion with patients is advised. Adequately powered, well-designed clinical trials are now needed, and multi-centre collaborations may be required to obtain the sample sizes required.
Beneficial and adverse effects of testosterone on the cardiovascular system in men.
Ruige, Johannes B; Ouwens, D Margriet; Kaufman, Jean-Marc
2013-11-01
The widespread use of T therapy, particularly in aging males, necessitates knowledge of the relationship between T and the cardiovascular system. The review is based on a 1970 to 2013 PubMed search with terms related to androgens in combination with cardiovascular disease, including T, dihydrotestosterone, trial, mortality, cardiovascular disease, myocardial infarction, blood pressure, endothelial function, dyslipidemia, thrombosis, ventricular function, and arrhythmia. Original articles, systematic reviews and meta-analyses, and relevant citations were screened. Low T has been linked to increased blood pressure, dyslipidemia, atherosclerosis, arrhythmia, thrombosis, endothelial dysfunction, as well as to impaired left ventricular function. On the one hand, a modest association is suggested between low endogenous T and incident cardiovascular disease or cardiovascular mortality, implying unrecognized beneficial T effects, residual confounding, or a relationship with health status. On the other hand, treatments with T to restore "normal concentrations" have so far not been proven to be beneficial with respect to cardiovascular disease; neither have they definitely shown specific adverse cardiovascular effects. The cardiovascular risk-benefit profile of T therapy remains largely evasive in view of a lack of well-designed and adequately powered randomized clinical trials. The important knowledge gap as to the exact relationship between T and cardiovascular disease would support a cautious, restrained approach to T therapy in aging men, pending clarification of benefits and risks by adequately powered clinical trials of sufficient duration.
Ma, Li-Xin; Liu, Jian-Ping
2012-01-01
To investigate whether the power of the effect size was based on adequate sample size in randomized controlled trials (RCTs) for the treatment of patients with type 2 diabetes mellitus (T2DM) using Chinese medicine. China Knowledge Resource Integrated Database (CNKI), VIP Database for Chinese Technical Periodicals (VIP), Chinese Biomedical Database (CBM), and Wangfang Data were systematically recruited using terms like "Xiaoke" or diabetes, Chinese herbal medicine, patent medicine, traditional Chinese medicine, randomized, controlled, blinded, and placebo-controlled. Limitation was set on the intervention course > or = 3 months in order to identify the information of outcome assessement and the sample size. Data collection forms were made according to the checking lists found in the CONSORT statement. Independent double data extractions were performed on all included trials. The statistical power of the effects size for each RCT study was assessed using sample size calculation equations. (1) A total of 207 RCTs were included, including 111 superiority trials and 96 non-inferiority trials. (2) Among the 111 superiority trials, fasting plasma glucose (FPG) and glycosylated hemoglobin HbA1c (HbA1c) outcome measure were reported in 9% and 12% of the RCTs respectively with the sample size > 150 in each trial. For the outcome of HbA1c, only 10% of the RCTs had more than 80% power. For FPG, 23% of the RCTs had more than 80% power. (3) In the 96 non-inferiority trials, the outcomes FPG and HbA1c were reported as 31% and 36% respectively. These RCTs had a samples size > 150. For HbA1c only 36% of the RCTs had more than 80% power. For FPG, only 27% of the studies had more than 80% power. The sample size for statistical analysis was distressingly low and most RCTs did not achieve 80% power. In order to obtain a sufficient statistic power, it is recommended that clinical trials should establish clear research objective and hypothesis first, and choose scientific and evidence-based study design and outcome measurements. At the same time, calculate required sample size to ensure a precise research conclusion.
Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi
2014-01-01
Adequate rest is essential to avoid fatigue and disruption of homeostasis. However, the neural mechanisms underlying the decision to rest are not well understood. In the present study, we aimed to clarify the neural mechanisms of this decision-making process using magnetoencephalography. Fifteen healthy volunteers participated in decision and control experiments performed in a cross-over fashion. In the decision experiment, participants performed 1,200 reverse Stroop test trials and were intermittently asked to decide whether they wanted to take a rest or continue. In the control experiments, participants performed 1,200 reverse Stroop test trials and were instructed to press a response button intermittently without making any decision. Changes in oscillatory brain activity were assessed using a narrow-band adaptive spatial filtering method. The levels of decrease in theta (4–8 Hz) band power in left Brodmann's area (BA) 31, alpha (8–13 Hz) band power in left BA 10 and BA 9, and beta (13–25 Hz) band power in right BA 46 and left BA 10 were greater in trials when the participant opted to rest (rest trials) than those in control trials. The decrease in theta band power in BA 31 in the rest trials was positively correlated with the subjective level of fatigue after the decision experiment. These results demonstrated that the dorsolateral prefrontal cortex, frontal pole, and posterior cingulate cortex play a role in the decision to rest in the presence of fatigue. These findings may help clarify the neural mechanisms underlying fatigue and fatigue-related problems. PMID:25303465
Clinical trial design for orthodontists.
Pandis, Nikolaos; Cobourne, Martyn T
2013-06-01
High-quality research should form the basis of all clinical practice. Randomized controlled trials currently provide the gold standard for investigating the effectiveness of treatment interventions and these are increasingly being used in orthodontics. Here we discuss the reasons why this form of investigation provides the most useful evidence for assessing treatment outcome. The methods available to achieve true randomization, a fundamental component in the design of these trials, are also discussed. In addition, we focus on how to minimize bias in clinical research, not only during the design and management of a trial, but also when disseminating results. We focus on the importance of using control groups correctly and describe methods that are available to adequately power a trial. Finally, we emphasise the importance of accurate and transparent reporting, which facilitates correct communication and assessment of the evidence.
Initial Results of Instrument-Flying Trials Conducted In A Single-Rotor Helicopter
NASA Technical Reports Server (NTRS)
Crim, Almer D; Reeder, John P; Whitten, James B
1953-01-01
Instrument-flying trials have been conducted in a single-rotor helicopter, the maneuver stability of which could be changed from satisfactory to unsatisfactory. The results indicated that existing longitudinal flying-qualities requirements based on contact flight were adequate for instrument flight at speeds above that for minimum power. However, lateral-directional problems were encountered at low speeds and during precision maneuvers. The adequacy, for helicopter use, of standard airplane instruments was also investigated, and the conclusion was reached that special instruments would be desirable under all conditions, and necessary for sustained low-speed instrument flight.
Chelation therapy to treat atherosclerosis, particularly in diabetes: is it time to reconsider?
Lamas, Gervasio A; Ergui, Ian
2016-08-01
Case reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes. The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. We discuss results and future research. Expert commentary: Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years, with a 41% relative reduction in risk of a cardiac event (p = 0.0002). These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. We are seeking participating sites for TACT2.
Syrjänen, Kari; Eronen, Katja; Hendolin, Panu; Paloheimo, Lea; Eklund, Carita; Bäckström, Anna; Suovaniemi, Osmo
2017-07-01
Because of the major health problems and annual economic burden caused by cigarette smoking, effective new tools for smoking intervention are urgently needed. Our previous randomized controlled trial (RCT) provided promising results on the efficacy of slow-release L-cysteine lozenge in smoking intervention, but the study was not adequately powered. To confirm in an adequately-powered study the results of the previous RCT implicating that effective elimination of acetaldehyde in saliva by slow-release L-cysteine (Acetium® lozenge, Biohit Oyj, Helsinki), would assist in smoking cessation by reducing acetaldehyde-enhanced nicotine addiction. On this matter, we undertook a double-blind, randomized, placebo-controlled trial comparing Acetium® lozenge and placebo in smoking intervention. A cohort of 1,998 cigarette smokers were randomly allocated to intervention (n=996) and placebo arms (n=1,002). At baseline, smoking history was recorded by a questionnaire, with nicotine dependence testing according to the Fagerström scale (FTND). The subjects used smoking diary recording the daily numbers of cigarettes, lozenges and subjective sensations of smoking. The data were analysed separately for point prevalence of abstinence (PPA) and prolonged abstinence (PA) endpoints. Altogether, 753 study subjects completed the trial per protocol (PP), 944 with violations (mITT), and the rest (n=301) were lost to follow-up (LTF). During the 6-month intervention, 331 subjects stopped smoking; 181 (18.2%) in the intervention arm and 150 (15.0%) in the placebo arm (OR=1.43; 95%CI=1.09-1.88); p=0.010). In the PP group, 170 (45.3%) quitted smoking in the intervention arm compared to 134 (35.4%) in the placebo arm (OR=1.51, 95%CI=1.12-2.02; p=0.006). In multivariate (Poisson regression) model, decreased level of smoking pleasure (p=0.010) and "smoking sensations changed" were powerful independent predictors of quit events (IRR=12.01; 95%CI=1.5-95.6). Acetium® lozenge, herein confirmed in an adequately powered study to be an effective means to aid smoking quit, represents a major breakthrough in the development of smoking intervention methods, because slow-release L-cysteine is non-toxic, with no side-effects or limitations of use. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
ERIC Educational Resources Information Center
Holtzapple, Carol K.
2011-01-01
Character education programs support the development of positive character traits in children and adults. Effective violence prevention programs improve pro-social competencies and reduce negative behaviors in students by enhancing protective factors (strong bonds with teachers; clear rules of conduct that are consistently enforced) and targeting…
Wolbers, Marcel; Heemskerk, Dorothee; Chau, Tran Thi Hong; Yen, Nguyen Thi Bich; Caws, Maxine; Farrar, Jeremy; Day, Jeremy
2011-02-02
In certain diseases clinical experts may judge that the intervention with the best prospects is the addition of two treatments to the standard of care. This can either be tested with a simple randomized trial of combination versus standard treatment or with a 2 x 2 factorial design. We compared the two approaches using the design of a new trial in tuberculous meningitis as an example. In that trial the combination of 2 drugs added to standard treatment is assumed to reduce the hazard of death by 30% and the sample size of the combination trial to achieve 80% power is 750 patients. We calculated the power of corresponding factorial designs with one- to sixteen-fold the sample size of the combination trial depending on the contribution of each individual drug to the combination treatment effect and the strength of an interaction between the two. In the absence of an interaction, an eight-fold increase in sample size for the factorial design as compared to the combination trial is required to get 80% power to jointly detect effects of both drugs if the contribution of the less potent treatment to the total effect is at least 35%. An eight-fold sample size increase also provides a power of 76% to detect a qualitative interaction at the one-sided 10% significance level if the individual effects of both drugs are equal. Factorial designs with a lower sample size have a high chance to be underpowered, to show significance of only one drug even if both are equally effective, and to miss important interactions. Pragmatic combination trials of multiple interventions versus standard therapy are valuable in diseases with a limited patient pool if all interventions test the same treatment concept, it is considered likely that either both or none of the individual interventions are effective, and only moderate drug interactions are suspected. An adequately powered 2 x 2 factorial design to detect effects of individual drugs would require at least 8-fold the sample size of the combination trial. Current Controlled Trials ISRCTN61649292.
The relationship between perceived discomfort of static posture holding and posture holding time.
Ogutu, Jack; Park, Woojin
2015-01-01
Few studies have investigated mathematical characteristics of the discomfort-time relationship during prolonged static posture holding (SPH) on an individual basis. Consequently, the discomfort-time relationship is not clearly understood at individual trial level. The objective of this study was to examine discomfort-time sequence data obtained from a large number of maximum-duration SPH trials to understand the perceived discomfort-posture holding time relationship at the individual SPH trial level. Thirty subjects (15 male, 15 female) participated in this study as paid volunteers. The subjects performed maximum-duration SPH trials employing 12 different wholebody static postures. The hand-held load for all the task trials was a ``generic'' box weighing 2 kg. Three mathematical functions, that is, linear, logarithmic and power functions were examined as possible mathematical models for representing individual discomfort-time profiles of SPH trials. Three different time increase patterns (negatively accelerated, linear and positively accelerated) were observed in the discomfort-time sequences data. The power function model with an additive constant term was found to adequately fit most (96.4%) of the observed discomfort-time sequences, and thus, was recommended as a general mathematical representation of the perceived discomfort-posture holding time relationship in SPH. The new knowledge on the nature of the discomfort-time relationship in SPH and the power function representation found in this study will facilitate analyzing discomfort-time data of SPH and developing future posture analysis tools for work-related discomfort control.
Chen, Henian; Zhang, Nanhua; Lu, Xiaosun; Chen, Sophie
2013-08-01
The method used to determine choice of standard deviation (SD) is inadequately reported in clinical trials. Underestimations of the population SD may result in underpowered clinical trials. This study demonstrates how using the wrong method to determine population SD can lead to inaccurate sample sizes and underpowered studies, and offers recommendations to maximize the likelihood of achieving adequate statistical power. We review the practice of reporting sample size and its effect on the power of trials published in major journals. Simulated clinical trials were used to compare the effects of different methods of determining SD on power and sample size calculations. Prior to 1996, sample size calculations were reported in just 1%-42% of clinical trials. This proportion increased from 38% to 54% after the initial Consolidated Standards of Reporting Trials (CONSORT) was published in 1996, and from 64% to 95% after the revised CONSORT was published in 2001. Nevertheless, underpowered clinical trials are still common. Our simulated data showed that all minimal and 25th-percentile SDs fell below 44 (the population SD), regardless of sample size (from 5 to 50). For sample sizes 5 and 50, the minimum sample SDs underestimated the population SD by 90.7% and 29.3%, respectively. If only one sample was available, there was less than 50% chance that the actual power equaled or exceeded the planned power of 80% for detecting a median effect size (Cohen's d = 0.5) when using the sample SD to calculate the sample size. The proportions of studies with actual power of at least 80% were about 95%, 90%, 85%, and 80% when we used the larger SD, 80% upper confidence limit (UCL) of SD, 70% UCL of SD, and 60% UCL of SD to calculate the sample size, respectively. When more than one sample was available, the weighted average SD resulted in about 50% of trials being underpowered; the proportion of trials with power of 80% increased from 90% to 100% when the 75th percentile and the maximum SD from 10 samples were used. Greater sample size is needed to achieve a higher proportion of studies having actual power of 80%. This study only addressed sample size calculation for continuous outcome variables. We recommend using the 60% UCL of SD, maximum SD, 80th-percentile SD, and 75th-percentile SD to calculate sample size when 1 or 2 samples, 3 samples, 4-5 samples, and more than 5 samples of data are available, respectively. Using the sample SD or average SD to calculate sample size should be avoided.
Jones, Philip M; Chow, Jeffrey T Y; Arango, Miguel F; Fridfinnson, Jason A; Gai, Nan; Lam, Kevin; Turkstra, Timothy P
2017-10-01
Randomized clinical trials (RCTs) provide high-quality evidence for clinical decision-making. Trial registration is one of the many tools used to improve the reporting of RCTs by reducing publication bias and selective outcome reporting bias. The purpose of our study is to examine whether RCTs published in the top 6 general anesthesiology journals were adequately registered and whether the reported primary and secondary outcomes corresponded to the originally registered outcomes. Following a prespecified protocol, an electronic database was used to systematically screen and extract data from RCTs published in the top 6 general anesthesiology journals by impact factor (Anaesthesia, Anesthesia & Analgesia, Anesthesiology, British Journal of Anaesthesia, Canadian Journal of Anesthesia, and European Journal of Anaesthesiology) during the years 2007, 2010, 2013, and 2015. A manual search of each journal's Table of Contents was performed (in duplicate) to identify eligible RCTs. An adequately registered trial was defined as being registered in a publicly available trials registry before the first patient being enrolled with an unambiguously defined primary outcome. For adequately registered trials, the outcomes registered in the trial registry were compared with the outcomes reported in the article, with outcome discrepancies documented and analyzed by the type of discrepancy. During the 4 years studied, there were 860 RCTs identified, with 102 RCTs determined to be adequately registered (12%). The proportion of adequately registered trials increased over time, with 38% of RCTs being adequately registered in 2015. The most common reason in 2015 for inadequate registration was registering the RCT after the first patient had already been enrolled. Among adequately registered trials, 92% had at least 1 primary or secondary outcome discrepancy. In 2015, 42% of RCTs had at least 1 primary outcome discrepancy, while 90% of RCTs had at least 1 secondary outcome discrepancy. Despite trial registration being an accepted best practice, RCTs published in anesthesiology journals have a high rate of inadequate registration. While mandating trial registration has increased the proportion of adequately registered trials over time, there is still an unacceptably high proportion of inadequately registered RCTs. Among adequately registered trials, there are high rates of discrepancies between registered and reported outcomes, suggesting a need to compare a published RCT with its trial registry entry to be able to fully assess the quality of the study. If clinicians base their decisions on evidence distorted by primary outcome switching, patient care could be negatively affected.
Recombinant activated factor VII for bleeding in patients without inherited bleeding disorders.
Selin, S; Tejani, A
2006-03-01
(1) Recombinant activated factor VII (rFVIIa) is licensed in Canada for the prevention and treatment of bleeding in hemophiliacs, but it is increasingly used to control bleeding in non-hemophilic patients during surgery, or during treatment for severe trauma or intracerebral hemorrhage (ICH). (2) In one clinical trial, there was a significant reduction in mortality among patients with ICH treated with rFVIIa. In another trial, administration of rFVIIa significantly reduced the number of trauma patients needing massive blood transfusions although there was no significant difference in mortality. (3) Adequately powered randomized controlled trials are needed to clarify the efficacy and safety of rFVIIa for non-bleeding disorder indications. Phase III trials in ICH and trauma are underway. (4) There is potential for non-hemophilic use, particularly if clinical efficacy and cost effectiveness are established.
Zhang, J; Chen, X; Zhu, Q; Cui, J; Cao, L; Su, J
2016-11-01
In recent years, the number of randomized controlled trials (RCTs) in the field of orthopaedics is increasing in Mainland China. However, randomized controlled trials (RCTs) are inclined to bias if they lack methodological quality. Therefore, we performed a survey of RCT to assess: (1) What about the quality of RCTs in the field of orthopedics in Mainland China? (2) Whether there is difference between the core journals of the Chinese department of orthopedics and Orthopaedics Traumatology Surgery & Research (OTSR). This research aimed to evaluate the methodological reporting quality according to the CONSORT statement of randomized controlled trials (RCTs) in seven key orthopaedic journals published in Mainland China over 5 years from 2010 to 2014. All of the articles were hand researched on Chongqing VIP database between 2010 and 2014. Studies were considered eligible if the words "random", "randomly", "randomization", "randomized" were employed to describe the allocation way. Trials including animals, cadavers, trials published as abstracts and case report, trials dealing with subgroups analysis, or trials without the outcomes were excluded. In addition, eight articles selected from Orthopaedics Traumatology Surgery & Research (OTSR) between 2010 and 2014 were included in this study for comparison. The identified RCTs are analyzed using a modified version of the Consolidated Standards of Reporting Trials (CONSORT), including the sample size calculation, allocation sequence generation, allocation concealment, blinding and handling of dropouts. A total of 222 RCTs were identified in seven core orthopaedic journals. No trials reported adequate sample size calculation, 74 (33.4%) reported adequate allocation generation, 8 (3.7%) trials reported adequate allocation concealment, 18 (8.1%) trials reported adequate blinding and 16 (7.2%) trials reported handling of dropouts. In OTSR, 1 (12.5%) trial reported adequate sample size calculation, 4 (50.0%) reported adequate allocation generation, 1 (12.5%) trials reported adequate allocation concealment, 2 (25.0%) trials reported adequate blinding and 5 (62.5%) trials reported handling of dropouts. There were statistical differences as for sample size calculation and handling of dropouts between papers from Mainland China and OTSR (P<0.05). The findings of this study show that the methodological reporting quality of RCTs in seven core orthopaedic journals from the Mainland China is far from satisfaction and it needs to further improve to keep up with the standards of the CONSORT statement. Level III case control. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Methodological reporting of randomized clinical trials in respiratory research in 2010.
Lu, Yi; Yao, Qiuju; Gu, Jie; Shen, Ce
2013-09-01
Although randomized controlled trials (RCTs) are considered the highest level of evidence, they are also subject to bias, due to a lack of adequately reported randomization, and therefore the reporting should be as explicit as possible for readers to determine the significance of the contents. We evaluated the methodological quality of RCTs in respiratory research in high ranking clinical journals, published in 2010. We assessed the methodological quality, including generation of the allocation sequence, allocation concealment, double-blinding, sample-size calculation, intention-to-treat analysis, flow diagrams, number of medical centers involved, diseases, funding sources, types of interventions, trial registration, number of times the papers have been cited, journal impact factor, journal type, and journal endorsement of the CONSORT (Consolidated Standards of Reporting Trials) rules, in RCTs published in 12 top ranking clinical respiratory journals and 5 top ranking general medical journals. We included 176 trials, of which 93 (53%) reported adequate generation of the allocation sequence, 66 (38%) reported adequate allocation concealment, 79 (45%) were double-blind, 123 (70%) reported adequate sample-size calculation, 88 (50%) reported intention-to-treat analysis, and 122 (69%) included a flow diagram. Multivariate logistic regression analysis revealed that journal impact factor ≥ 5 was the only variable that significantly influenced adequate allocation sequence generation. Trial registration and journal impact factor ≥ 5 significantly influenced adequate allocation concealment. Medical interventions, trial registration, and journal endorsement of the CONSORT statement influenced adequate double-blinding. Publication in one of the general medical journal influenced adequate sample-size calculation. The methodological quality of RCTs in respiratory research needs improvement. Stricter enforcement of the CONSORT statement should enhance the quality of RCTs.
2011-01-01
Background In certain diseases clinical experts may judge that the intervention with the best prospects is the addition of two treatments to the standard of care. This can either be tested with a simple randomized trial of combination versus standard treatment or with a 2 × 2 factorial design. Methods We compared the two approaches using the design of a new trial in tuberculous meningitis as an example. In that trial the combination of 2 drugs added to standard treatment is assumed to reduce the hazard of death by 30% and the sample size of the combination trial to achieve 80% power is 750 patients. We calculated the power of corresponding factorial designs with one- to sixteen-fold the sample size of the combination trial depending on the contribution of each individual drug to the combination treatment effect and the strength of an interaction between the two. Results In the absence of an interaction, an eight-fold increase in sample size for the factorial design as compared to the combination trial is required to get 80% power to jointly detect effects of both drugs if the contribution of the less potent treatment to the total effect is at least 35%. An eight-fold sample size increase also provides a power of 76% to detect a qualitative interaction at the one-sided 10% significance level if the individual effects of both drugs are equal. Factorial designs with a lower sample size have a high chance to be underpowered, to show significance of only one drug even if both are equally effective, and to miss important interactions. Conclusions Pragmatic combination trials of multiple interventions versus standard therapy are valuable in diseases with a limited patient pool if all interventions test the same treatment concept, it is considered likely that either both or none of the individual interventions are effective, and only moderate drug interactions are suspected. An adequately powered 2 × 2 factorial design to detect effects of individual drugs would require at least 8-fold the sample size of the combination trial. Trial registration Current Controlled Trials ISRCTN61649292 PMID:21288326
Clinical trials bureaucracy: unintended consequences of well-intentioned policy.
Califf, Robert M
2006-01-01
As randomized controlled trials have become the 'gold standard' for medical research, a complex regulatory structure for the conduct of clinical trials has emerged. However, this structure has not been adequately assessed to ensure that regulations governing human subjects research actually produce the desired effects. Our purpose is to identify some of the major shortcomings in the current regulatory system of human clinical trials oversight, and to propose some potential solutions to these problems. We discuss the evolution of the current US regulatory environment and its application in the context of several widely-used drug therapies. Despite numerous randomized controlled trials, performed within a structure of extensive documentation and data collection, serious shortcomings in a number of pharmaceutical therapies were not detected until after the drugs were approved and widely adopted by clinicians. The current system of regulatory bureaucracy in clinical trials has led to an extremely expensive research paradigm that, in spite of complex systems of oversight and exhaustive data collection, cannot be shown to adequately ensure the integrity of the research process and the protection of human research subjects. Some parts of the system, including Research Ethics Review Boards, may not be well-suited to carrying out their core mission of overseeing research conduct, and other aspects of clinical trials regulatory structure, such as monitoring/auditing review and adverse event reporting, may constitute a waste of money and resources. Misdirected data collection and adverse events reporting divert valuable resources and hamper development of large, simple clinical trials powered to definitively answer important research questions. Careful scrutiny of the utility of current or proposed regulatory schemes is required to ensure the integrity of human subjects research and to enhance the effectiveness of research dollars.
Statistical inference on censored data for targeted clinical trials under enrichment design.
Chen, Chen-Fang; Lin, Jr-Rung; Liu, Jen-Pei
2013-01-01
For the traditional clinical trials, inclusion and exclusion criteria are usually based on some clinical endpoints; the genetic or genomic variability of the trial participants are not totally utilized in the criteria. After completion of the human genome project, the disease targets at the molecular level can be identified and can be utilized for the treatment of diseases. However, the accuracy of diagnostic devices for identification of such molecular targets is usually not perfect. Some of the patients enrolled in targeted clinical trials with a positive result for the molecular target might not have the specific molecular targets. As a result, the treatment effect may be underestimated in the patient population truly with the molecular target. To resolve this issue, under the exponential distribution, we develop inferential procedures for the treatment effects of the targeted drug based on the censored endpoints in the patients truly with the molecular targets. Under an enrichment design, we propose using the expectation-maximization algorithm in conjunction with the bootstrap technique to incorporate the inaccuracy of the diagnostic device for detection of the molecular targets on the inference of the treatment effects. A simulation study was conducted to empirically investigate the performance of the proposed methods. Simulation results demonstrate that under the exponential distribution, the proposed estimator is nearly unbiased with adequate precision, and the confidence interval can provide adequate coverage probability. In addition, the proposed testing procedure can adequately control the size with sufficient power. On the other hand, when the proportional hazard assumption is violated, additional simulation studies show that the type I error rate is not controlled at the nominal level and is an increasing function of the positive predictive value. A numerical example illustrates the proposed procedures. Copyright © 2013 John Wiley & Sons, Ltd.
Chu, Rong; Walter, Stephen D.; Guyatt, Gordon; Devereaux, P. J.; Walsh, Michael; Thorlund, Kristian; Thabane, Lehana
2012-01-01
Background Chance imbalance in baseline prognosis of a randomized controlled trial can lead to over or underestimation of treatment effects, particularly in trials with small sample sizes. Our study aimed to (1) evaluate the probability of imbalance in a binary prognostic factor (PF) between two treatment arms, (2) investigate the impact of prognostic imbalance on the estimation of a treatment effect, and (3) examine the effect of sample size (n) in relation to the first two objectives. Methods We simulated data from parallel-group trials evaluating a binary outcome by varying the risk of the outcome, effect of the treatment, power and prevalence of the PF, and n. Logistic regression models with and without adjustment for the PF were compared in terms of bias, standard error, coverage of confidence interval and statistical power. Results For a PF with a prevalence of 0.5, the probability of a difference in the frequency of the PF≥5% reaches 0.42 with 125/arm. Ignoring a strong PF (relative risk = 5) leads to underestimating the strength of a moderate treatment effect, and the underestimate is independent of n when n is >50/arm. Adjusting for such PF increases statistical power. If the PF is weak (RR = 2), adjustment makes little difference in statistical inference. Conditional on a 5% imbalance of a powerful PF, adjustment reduces the likelihood of large bias. If an absolute measure of imbalance ≥5% is deemed important, including 1000 patients/arm provides sufficient protection against such an imbalance. Two thousand patients/arm may provide an adequate control against large random deviations in treatment effect estimation in the presence of a powerful PF. Conclusions The probability of prognostic imbalance in small trials can be substantial. Covariate adjustment improves estimation accuracy and statistical power, and hence should be performed when strong PFs are observed. PMID:22629322
Blinded sample size re-estimation in three-arm trials with 'gold standard' design.
Mütze, Tobias; Friede, Tim
2017-10-15
In this article, we study blinded sample size re-estimation in the 'gold standard' design with internal pilot study for normally distributed outcomes. The 'gold standard' design is a three-arm clinical trial design that includes an active and a placebo control in addition to an experimental treatment. We focus on the absolute margin approach to hypothesis testing in three-arm trials at which the non-inferiority of the experimental treatment and the assay sensitivity are assessed by pairwise comparisons. We compare several blinded sample size re-estimation procedures in a simulation study assessing operating characteristics including power and type I error. We find that sample size re-estimation based on the popular one-sample variance estimator results in overpowered trials. Moreover, sample size re-estimation based on unbiased variance estimators such as the Xing-Ganju variance estimator results in underpowered trials, as it is expected because an overestimation of the variance and thus the sample size is in general required for the re-estimation procedure to eventually meet the target power. To overcome this problem, we propose an inflation factor for the sample size re-estimation with the Xing-Ganju variance estimator and show that this approach results in adequately powered trials. Because of favorable features of the Xing-Ganju variance estimator such as unbiasedness and a distribution independent of the group means, the inflation factor does not depend on the nuisance parameter and, therefore, can be calculated prior to a trial. Moreover, we prove that the sample size re-estimation based on the Xing-Ganju variance estimator does not bias the effect estimate. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Boden, Ianthe; Browning, Laura; Skinner, Elizabeth H; Reeve, Julie; El-Ansary, Doa; Robertson, Iain K; Denehy, Linda
2015-12-15
Post-operative pulmonary complications are a significant problem following open upper abdominal surgery. Preliminary evidence suggests that a single pre-operative physiotherapy education and preparatory lung expansion training session alone may prevent respiratory complications more effectively than supervised post-operative breathing and coughing exercises. However, the evidence is inconclusive due to methodological limitations. No well-designed, adequately powered, randomised controlled trial has investigated the effect of pre-operative education and training on post-operative respiratory complications, hospital length of stay, and health-related quality of life following upper abdominal surgery. The Lung Infection Prevention Post Surgery - Major Abdominal- with Pre-Operative Physiotherapy (LIPPSMAck POP) trial is a pragmatic, investigator-initiated, bi-national, multi-centre, patient- and assessor-blinded, parallel group, randomised controlled trial, powered for superiority. Four hundred and forty-one patients scheduled for elective open upper abdominal surgery at two Australian and one New Zealand hospital will be randomised using concealed allocation to receive either i) an information booklet or ii) an information booklet, plus one additional pre-operative physiotherapy education and training session. The primary outcome is respiratory complication incidence using standardised diagnostic criteria. Secondary outcomes include hospital length of stay and costs, pneumonia diagnosis, intensive care unit readmission and length of stay, days/h to mobilise >1 min and >10 min, and, at 6 weeks post-surgery, patient reported complications, health-related quality of life, and physical capacity. The LIPPSMAck POP trial is a multi-centre randomised controlled trial powered and designed to investigate whether a single pre-operative physiotherapy session prevents post-operative respiratory complications. This trial standardises post-operative assisted ambulation and physiotherapy, measures many known confounders, and includes a post-discharge follow-up of complication rates, functional capacity, and health-related quality of life. This trial is currently recruiting. Australian New Zealand Clinical Trials Registry number: ACTRN12613000664741 , 19 June 2013.
Quality of radiotherapy reporting in randomized controlled trials of prostate cancer.
Soon, Yu Yang; Chen, Desiree; Tan, Teng Hwee; Tey, Jeremy
2018-06-07
Good radiotherapy reporting in clinical trials of prostate radiotherapy is important because it will allow accurate reproducibility of radiotherapy treatment and minimize treatment variations that can affect patient outcomes. The aim of our study is to assess the quality of prostate radiotherapy (RT) treatment reporting in randomized controlled trials in prostate cancer. We searched MEDLINE for randomized trials of prostate cancer, published from 1996 to 2016 and included prostate RT as one of the intervention arms. We assessed if the investigators reported the ten criteria adequately in the trial reports: RT dose prescription method; RT dose-planning procedures; organs at risk (OAR) dose constraints; target volume definition, simulation procedures; treatment verification procedures; total RT dose; fractionation schedule; conduct of quality assurance (QA) as well as presence or absence of deviations in RT treatment planning and delivery. We performed multivariate logistic regression to determine the factors that may influence the quality of reporting. We found 59 eligible trials. There was significant variability in the quality of reporting. Target volume definition, total RT dose and fractionation schedule were reported adequately in 97% of included trials. OAR constraints, simulation procedures and presence or absence of deviations in RT treatment planning and delivery were reported adequately in 30% of included trials. Twenty-four trials (40%) reported seven criteria or more adequately. Multivariable logistic analysis showed that trials that published their quality assurance results and cooperative group trials were more likely to have adequate quality in reporting in at least seven criteria. There is significant variability in the quality of reporting on prostate radiotherapy treatment in randomized trials of prostate cancer. We need to have consensus guidelines to standardize the reporting of radiotherapy treatment in randomized trials.
Austin, Peter C; Schuster, Tibor; Platt, Robert W
2015-10-15
Estimating statistical power is an important component of the design of both randomized controlled trials (RCTs) and observational studies. Methods for estimating statistical power in RCTs have been well described and can be implemented simply. In observational studies, statistical methods must be used to remove the effects of confounding that can occur due to non-random treatment assignment. Inverse probability of treatment weighting (IPTW) using the propensity score is an attractive method for estimating the effects of treatment using observational data. However, sample size and power calculations have not been adequately described for these methods. We used an extensive series of Monte Carlo simulations to compare the statistical power of an IPTW analysis of an observational study with time-to-event outcomes with that of an analysis of a similarly-structured RCT. We examined the impact of four factors on the statistical power function: number of observed events, prevalence of treatment, the marginal hazard ratio, and the strength of the treatment-selection process. We found that, on average, an IPTW analysis had lower statistical power compared to an analysis of a similarly-structured RCT. The difference in statistical power increased as the magnitude of the treatment-selection model increased. The statistical power of an IPTW analysis tended to be lower than the statistical power of a similarly-structured RCT.
Tsivgoulis, Georgios; Alexandrov, Andrei V; Katsanos, Aristeidis H; Barlinn, Kristian; Mikulik, Robert; Lambadiari, Vaia; Bonakis, Anastasios; Alexandrov, Anne W
2017-08-01
Even though current guidelines suggest that noninvasive ventilatory correction (NIVC) could be considered for acute ischemic stroke patients with obstructive sleep apnea, available evidence is conflicting, with no adequately powered randomized clinical trial being available to date. We conducted a systematic review and meta-analysis of all available literature data evaluating the effect of NIVC on neurological improvement (based on decrease in National Institutes of Health Stroke Scale score), vascular events (recurrent stroke, transient ischemic attack, myocardial infarction and unstable angina), and mortality during the follow-up period. We identified 4 randomized clinical trials and 1 prospectively matched observational cohort, comprising a total of 389 patients (59.8% males, mean age: 64.4 years). The risk of both performance and detection bias was considered high in most of the included randomized clinical trials because of the lack of blinding in participants, personnel and/or outcome assessors. The mean decrease in National Institutes of Health Stroke Scale scores during the first (≤30) days of acute ischemic stroke was found to be greater in NIVC-treated patients in comparison to controls (standardized mean difference, 0.38; 95% confidence interval, 0.11-0.66; P =0.007). However, no significant differences were detected between NIVC-treated acute ischemic stroke patients and controls on both the risk of vascular events (risk ratio, 0.53; 95% confidence interval, 0.25-1.14; P =0.11) and mortality (risk ratio, 0.71; 95% confidence interval, 0.37-1.36; P =0.30). No evidence of heterogeneity ( I 2 =0%; P for Cochran Q>0.50) or publication bias were detected in all analyses. NIVC seems to be associated with greater short-term neurological improvement in acute ischemic stroke patients with obstructive sleep apnea. This finding deserves further investigation within the settings of an adequately powered, sham-control, randomized clinical trial. © 2017 American Heart Association, Inc.
Stabilized Acoustic Levitation of Dense Materials Using a High-Powered Siren
NASA Technical Reports Server (NTRS)
Gammell, P. M.; Croonquist, A.; Wang, T. G.
1982-01-01
Stabilized acoustic levitation and manipulation of dense (e.g., steel) objects of 1 cm diameter, using a high powered siren, was demonstrated in trials that investigated the harmonic content and spatial distribution of the acoustic field, as well as the effect of sample position and reflector geometries on the acoustic field. Although further optimization is possible, the most stable operation achieved is expected to be adequate for most containerless processing applications. Best stability was obtained with an open reflector system, using a flat lower reflector and a slightly concave upper one. Operation slightly below resonance enhances stability as this minimizes the second harmonic, which is suspected of being a particularly destabilizing influence.
Biedrzycki, Barbara A
2011-07-01
To describe the adequacy of research information among people with cancer at the time they accept or decline participation in a cancer clinical trial. Cross-sectional, descriptive. An urban, academic, National Cancer Institute-designated comprehensive cancer center. 197 patients with advanced gastrointestinal cancer. Mailed survey; self-reported data. Adequacy of research information (actual knowledge, perceived adequacy of information, and perceived understanding), cancer clinical trial participation, and satisfaction with the decision to participate. Most respondents (88%) perceived themselves as having adequate information to make an informed decision regarding cancer clinical trial participation. In addition, 35% demonstrated adequate knowledge of basic clinical research. Patients decide to accept or decline cancer clinical trials without having adequate knowledge. Nurses have an important role in educating patients regarding cancer clinical trials. The ideal teachable moment may not occur at the time of diagnosis; other less stressful opportunities may present when the patient is more receptive.
Anker, Stefan D; Schroeder, Stefan; Atar, Dan; Bax, Jeroen J; Ceconi, Claudio; Cowie, Martin R; Crisp, Adam; Dominjon, Fabienne; Ford, Ian; Ghofrani, Hossein-Ardeschir; Gropper, Savion; Hindricks, Gerhard; Hlatky, Mark A; Holcomb, Richard; Honarpour, Narimon; Jukema, J Wouter; Kim, Albert M; Kunz, Michael; Lefkowitz, Martin; Le Floch, Chantal; Landmesser, Ulf; McDonagh, Theresa A; McMurray, John J; Merkely, Bela; Packer, Milton; Prasad, Krishna; Revkin, James; Rosano, Giuseppe M C; Somaratne, Ransi; Stough, Wendy Gattis; Voors, Adriaan A; Ruschitzka, Frank
2016-05-01
Composite endpoints are commonly used as the primary measure of efficacy in heart failure clinical trials to assess the overall treatment effect and to increase the efficiency of trials. Clinical trials still must enrol large numbers of patients to accrue a sufficient number of outcome events and have adequate power to draw conclusions about the efficacy and safety of new treatments for heart failure. Additionally, the societal and health system perspectives on heart failure have raised interest in ascertaining the effects of therapy on outcomes such as repeat hospitalization and the patient's burden of disease. Thus, novel methods for using composite endpoints in clinical trials (e.g. clinical status composite endpoints, recurrent event analyses) are being applied in current and planned trials. Endpoints that measure functional status or reflect the patient experience are important but used cautiously because heart failure treatments may improve function yet have adverse effects on mortality. This paper discusses the use of traditional and new composite endpoints, identifies qualities of robust composites, and outlines opportunities for future research. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.
Gold, Diane R; Litonjua, Augusto A; Carey, Vincent J; Manson, JoAnn E; Buring, Julie E; Lee, I-Min; Gordon, David; Walter, Joseph; Friedenberg, Georgina; Hankinson, John L; Copeland, Trisha; Luttmann-Gibson, Heike
2016-03-01
Laboratory and observational research studies suggest that vitamin D and marine omega-3 fatty acids may reduce risk for pneumonia, acute exacerbations of respiratory diseases including chronic obstructive lung disease (COPD) or asthma, and decline of lung function, but prevention trials with adequate dosing, adequate power, and adequate time to follow-up are lacking. The ongoing Lung VITAL study is taking advantage of a large clinical trial-the VITamin D and OmegA-3 TriaL (VITAL)--to conduct the first major evaluation of the influences of vitamin D and marine omega-3 fatty acid supplementation on pneumonia risk, respiratory exacerbation episodes, asthma control and lung function in adults. VITAL is a 5-year U.S.-wide randomized, double-blind, placebo-controlled, 2 × 2 factorial trial of supplementation with vitamin D3 ([cholecalciferol], 2000 IU/day) and marine omega-3 FA (Omacor® fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA], 1g/day) for primary prevention of CVD and cancer among men and women, at baseline aged ≥50 and ≥55, respectively, with 5107 African Americans. In a subset of 1973 participants from 11 urban U.S. centers, lung function is measured before and two years after randomization. Yearly follow-up questionnaires assess incident pneumonia in the entire randomized population, and exacerbations of respiratory disease, asthma control and dyspnea in a subpopulation of 4314 randomized participants enriched, as shown in presentation of baseline characteristics, for respiratory disease, respiratory symptoms, and history of cigarette smoking. Self-reported pneumonia hospitalization will be confirmed by medical record review, and exacerbations will be confirmed by Center for Medicare and Medicaid Services data review. Copyright © 2016 Elsevier Inc. All rights reserved.
Hoffmann, Tammy C; Walker, Marion F; Langhorne, Peter; Eames, Sally; Thomas, Emma; Glasziou, Paul
2015-01-01
Objective To assess, in a sample of systematic reviews of non-pharmacological interventions, the completeness of intervention reporting, identify the most frequently missing elements, and assess review authors’ use of and beliefs about providing intervention information. Design Analysis of a random sample of systematic reviews of non-pharmacological stroke interventions; online survey of review authors. Data sources and study selection The Cochrane Library and PubMed were searched for potentially eligible systematic reviews and a random sample of these assessed for eligibility until 60 (30 Cochrane, 30 non-Cochrane) eligible reviews were identified. Data collection In each review, the completeness of the intervention description in each eligible trial (n=568) was assessed by 2 independent raters using the Template for Intervention Description and Replication (TIDieR) checklist. All review authors (n=46) were invited to complete a survey. Results Most reviews were missing intervention information for the majority of items. The most incompletely described items were: modifications, fidelity, materials, procedure and tailoring (missing from all interventions in 97%, 90%, 88%, 83% and 83% of reviews, respectively). Items that scored better, but were still incomplete for the majority of reviews, were: ‘when and how much’ (in 31% of reviews, adequate for all trials; in 57% of reviews, adequate for some trials); intervention mode (in 22% of reviews, adequate for all trials; in 38%, adequate for some trials); and location (in 19% of reviews, adequate for all trials). Of the 33 (71%) authors who responded, 58% reported having further intervention information but not including it, and 70% tried to obtain information. Conclusions Most focus on intervention reporting has been directed at trials. Poor intervention reporting in stroke systematic reviews is prevalent, compounded by poor trial reporting. Without adequate intervention descriptions, the conduct, usability and interpretation of reviews are restricted and therefore, require action by trialists, systematic reviewers, peer reviewers and editors. PMID:26576811
Oral anti-pseudomonal antibiotics for cystic fibrosis.
Remmington, Tracey; Jahnke, Nikki; Harkensee, Christian
2016-07-14
Pseudomonas aeruginosa is the most common bacterial pathogen causing lung infections in people with cystic fibrosis and appropriate antibiotic therapy is vital. Antibiotics for pulmonary exacerbations are usually given intravenously, and for long-term treatment, via a nebuliser. Oral anti-pseudomonal antibiotics with the same efficacy and safety as intravenous or nebulised antibiotics would benefit people with cystic fibrosis due to ease of treatment and avoidance of hospitalisation. This is an update of a previous review. To determine the benefit or harm of oral anti-pseudomonal antibiotic therapy for people with cystic fibrosis, colonised with Pseudomonas aeruginosa, in the:1. treatment of a pulmonary exacerbation; and2. long-term treatment of chronic infection. 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.We contacted pharmaceutical companies and checked reference lists of identified trials.Date of last search: 08 July 2016. Randomised or quasi-randomised controlled trials comparing any dose of oral anti-pseudomonal antibiotics, to other combinations of inhaled, oral or intravenous antibiotics, or to placebo or usual treatment for pulmonary exacerbations and long-term treatment. Two authors independently selected the trials, extracted data and assessed quality. We contacted trial authors to obtain missing information. We included three trials examining pulmonary exacerbations (171 participants) and two trials examining long-term therapy (85 participants). We regarded the most important outcomes as quality of life and lung function. The analysis did not identify any statistically significant difference between oral anti-pseudomonal antibiotics and other treatments for these outcome measures for either pulmonary exacerbations or long-term treatment. One of the included trials reported significantly better lung function when treating a pulmonary exacerbation with ciprofloxacin when compared with intravenous treatment; however, our analysis did not confirm this finding. We found no evidence of difference between oral anti-pseudomonal antibiotics and other treatments regarding adverse events or development of antibiotic resistance, but trials were not adequately powered to detect this. None of the studies had a low risk of bias from blinding which may have an impact particularly on subjective outcomes such as quality of life. The risk of bias for other criteria could not be clearly stated across the studies. We found no conclusive evidence that an oral anti-pseudomonal antibiotic regimen is more or less effective than an alternative treatment for either pulmonary exacerbations or long-term treatment of chronic infection with P. aeruginosa. Until results of adequately-powered future trials are available, treatment needs to be selected on a pragmatic basis, based upon any available non-randomised evidence, the clinical circumstances of the individual, the known effectiveness of drugs against local strains and upon individual preference.
Follow-up of colorectal cancer patients after resection with curative intent-the GILDA trial.
Grossmann, Erik M; Johnson, Frank E; Virgo, Katherine S; Longo, Walter E; Fossati, Rolando
2004-01-01
Surgery remains the primary treatment of colorectal cancer. Data are lacking to delineate the optimal surveillance strategy following resection. A large-scale multi-center European study is underway to address this issue (Gruppo Italiano di Lavoro per la Diagnosi Anticipata-GILDA). Following primary surgery with curative intent, stratification, and randomization at GILDA headquarters, colon cancer patients are then assigned to a more intensive or less intensive surveillance regimen. Rectal cancer patients undergoing curative resection are similarly randomized, with their follow-up regimens placing more emphasis on detection of local recurrence. Target recruitment for the study will be 1500 patients to achieve a statistical power of 80% (assuming an alpha of 0.05 and a hazard-rate reduction of >24%). Since the trial opened in 1998, 985 patients have been randomized from 41 centers as of February 2004. There were 496 patients randomized to the less intensive regimens, and 489 randomized to the more intensive regimens. The mean duration of follow-up is 14 months. 75 relapses (15%) and 32 deaths (7%) had been observed in the two more intensive follow-up arms, while 64 relapses (13%) and 24 deaths (5%) had been observed in the two less intensive arms as of February 2004. This trial should provide the first evidence based on an adequately powered randomized trial to determine the optimal follow-up strategy for colorectal cancer patients. This trial is open to US centers, and recruitment continues.
The Importance and Role of Intracluster Correlations in Planning Cluster Trials
Preisser, John S.; Reboussin, Beth A.; Song, Eun-Young; Wolfson, Mark
2008-01-01
There is increasing recognition of the critical role of intracluster correlations of health behavior outcomes in cluster intervention trials. This study examines the estimation, reporting, and use of intracluster correlations in planning cluster trials. We use an estimating equations approach to estimate the intracluster correlations corresponding to the multiple-time-point nested cross-sectional design. Sample size formulae incorporating 2 types of intracluster correlations are examined for the purpose of planning future trials. The traditional intracluster correlation is the correlation among individuals within the same community at a specific time point. A second type is the correlation among individuals within the same community at different time points. For a “time × condition” analysis of a pretest–posttest nested cross-sectional trial design, we show that statistical power considerations based upon a posttest-only design generally are not an adequate substitute for sample size calculations that incorporate both types of intracluster correlations. Estimation, reporting, and use of intracluster correlations are illustrated for several dichotomous measures related to underage drinking collected as part of a large nonrandomized trial to enforce underage drinking laws in the United States from 1998 to 2004. PMID:17879427
Porat, Shay; Amsalem, Hagai; Shah, Prakesh S; Murphy, Kellie E
2012-11-01
The purpose of this study was to review systematically the efficacy of transabdominal amnioinfusion (TA) in early preterm premature rupture of membranes (PPROM). We conducted a literature search of EMBASE, MEDLINE, and ClinicalTrials.gov databases and identified studies in which TA was used in cases of proven PPROM and oligohydramnios. Risk of bias was assessed for observational studies and randomized controlled trials. Primary outcomes were latency period and perinatal mortality rates. Four observational studies (n = 147) and 3 randomized controlled trials (n = 165) were eligible. Pooled latency period was 14.4 (range, 8.2-20.6) and 11.41 (range -3.4 to 26.2) days longer in the TA group in the observational and the randomized controlled trials, respectively. Perinatal mortality rates were reduced among the treatment groups in both the observational studies (odds ratio, 0.12; 95% confidence interval, 0.02-0.61) and the randomized controlled trials (odds ratio, 0.33; 95% confidence interval, 0.10-1.12). Serial TA for early PPROM may improve early PPROM-associated morbidity and mortality rates. Additional adequately powered randomized control trials are needed. Copyright © 2012 Mosby, Inc. All rights reserved.
2014-01-01
Background Studies suggest that expectations powerfully shape clinical outcomes. For subjective outcomes in adequately blinded trials, health improvements are substantial and largely explained by non-specific factors. The objective of this study was to investigate if unblinding in randomized controlled trials (RCTs) is associated with enhanced placebo effects for intervention groups and nocebo effects for placebo groups. For these effects, a secondary objective was to explore potential moderating factors. Methods We included RCTs that investigated the efficacy of phosphodiesterase-5 (PDE-5) inhibitors for male erectile dysfunction by comparing one PDE-5 inhibitor to placebo. In addition, to be included studies must have reported scores for change from baseline, or baseline and final International Index of Erectile Functioning-Erectile Functioning domain score (IIEF-EF), and be published in either English, French, Dutch, or German. We searched for both published and unpublished relevant trials using PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials, a clinical trials register (clinicaltrials.gov) and the Food and Drug Administration clinical reviews through March 2012. We evaluated the blinding status of trials with the Cochrane Risk of Bias Tool, using the domains of allocation sequence concealment, blinding of participants, healthcare providers and outcome assessors. Across these four domains, studies that scored low risk of bias were judged to be adequately blinded and studies that scored unclear or high risk of bias were judged to be inadequately blinded. Results We included 110 studies (205 journal publications and 2 unpublished sources) that involved 23,877 participants; 93 (85%), 51 (46%), 93 (85%) and 93 (85%) studies were assessed with an unclear risk of bias for allocation concealment, blinding of participant, blinding of caregiver and blinding of outcome assessor, respectively. None of the studies reported testing of blinding. None of the 205 journal publications provided sufficient details to assess allocation concealment, blinding of participants, caregivers and outcome assessors. After contacting authors for additional information, we judged five studies to be adequately (n = 1,202) and 16 to be inadequately (n = 3,006) blinded. The IIEF-EF score for placebo groups in adequately blinded trials versus inadequately blinded trials was 1.92 points (95% CI, 0.64 to 3.20) versus 1.56 (95% CI, 0.93 to 2.20), respectively. The IIEF-EF score for intervention groups in adequately blinded trials versus inadequately blinded trials was 9.40 (95% CI, 6.96 to 11.83) versus 8.33 (95% CI, 7.29 to 9.37), respectively. In a secondary analysis, prior experience with the drug affected the scores; in placebo groups with participants naïve to the intervention the score was 2.89 (95% CI, 2.33 to 3.45) versus -0.11 (95% CI, -2.06 to 1.84) with participants having prior experience. In the intervention groups, these scores were 7.99 (95% CI, 6.85 to 9.14) versus 8.33 (95% CI, 7.51 to 9.16), respectively. Unblinding lowered placebo scores (creating a nocebo effect) by 19% (0.33 points; 95% CI, -0.96 to 1.62). Unblinding lowered intervention scores by 11% (1.0; 95% CI, -1.35 to 3.47). The results provided no conclusive evidence for nocebo or enhanced placebo effects. Patients taking a PDE-5 inhibitor for the first time experience a larger placebo effect that accounts for 35% of the total effect. Conclusions Given the overall poor reporting of blinding in clinical trial reports and the small number of trials that could be rated as adequately or inadequately blinded, we could not draw any robust conclusions about the existence or absence of nocebo and enhanced placebo effects. A large placebo effect was found for patients taking PDE-5 inhibitors for the first time. It was not clear if previous exposure to the drug impacted trial blinding. We found clear evidence that studies assessing a subjective continuous outcome fail to report on measures taken to secure double blinding. Although we observed a trend for the presence of a nocebo effect, there was insufficient evidence to quantify its impact on expectations. RCTs with patients with no prior experience with PDE-5 inhibitors reported larger placebo effects and possibly these studies were better blinded. Future research should further investigate the factors that contribute to blinding and their impact on health outcomes in randomized trials of subjectively assessed conditions. This research is part of a PhD project and has no external funding. The authors have no competing interests to declare. PMID:24555576
Towards Defining Adequate Lithium Trials for Individuals with Mental Retardation and Mental Illness.
ERIC Educational Resources Information Center
Pary, Robert J.
1991-01-01
Use of lithium with mentally retarded individuals with psychiatric conditions and/or behavior disturbances is discussed. The paper describes components of an adequate clinical trial and reviews case studies and double-blind cases. The paper concludes that aggression is the best indicator for lithium use, and reviews treatment parameters and…
Nagy, Pál; Kövér, Krisztián; Gera, István; Horváth, Attila
2016-03-01
The removal of dental plaque plays an essential role in the maintenance of oral health. Numerous powered and manual toothbrushes were manufactured to achieve this goal, but even up to this day different opinions and research results have been revealed to assess the priority of the mentioned devices. Comparison of powered and manual toothbrushes on the basis of periodontal parameters and safety. Electronic search of the databases of MEDLINE and EMBASE (until May 2014) was carried out with the help of keywords in order to find relevant trials. The inclusion criteria were as follows: randomised controlled clinical trials, adult population, the presence of at least 15 permanent teeth. Split-mouth trials and interventions carried out by dental professionals, were excluded. Primary outcomes were the changes of plaque and gingival indices, while secondary outcomes were probing pocket depth (PPD), safety and quality assessment. The effect-size of the interventions was expressed by the standardised mean difference (SMD) with 95% confidence interval (CI). Random-effects models were performed. Electronic search resulted in 173 hits. 21 trials with the total number of 1500 subjects were then eligible for the meta-analysis. Both toothbrushes were safe, without considerable side effects on soft or hard tissues. Powered toothbrushes seemed to be generally more effective in removing plaque (-9%), reducing gingivitis (-6%) and preventing calculus formation. The SMDs for plaque and gingival indices were -0,40 (95% Cl: -0,95 to -0,16) and -0,29 (95% Cl: -0,56 to -0,03) respectively, in favour of the powered devices. There was no significant difference in changes of PPD. By further dividing the powered toothbrushes according to their mode of action, the plaque removal effect of the rotation oscillation (plus three dimensional), side to side sonic and ultrasonic toothbrushes seemed to be significantly better, than their manual ones, while the counter oscillation and the ionic toothbrushes did not perform better. Quality assessment and sensitivity analysis revealed various types of bias up to a certain extent. Consequently, no trial was found to be eligible for the highest quality criteria. The investigated rotation oscillation and vibrating toothbrushes appeared to be statistically more effective than their manual counterparts, although there is little known about its clinical relevance. The advantage of the electric toothbrushes disappears in case of adequately instructed and motivated patients that highlights the importance of individualised oral hygiene education. The design of the trials shows high heterogeneity, therefore their clinical implications should be handled carefully.
Interventions for dysarthria due to stroke and other adult-acquired, non-progressive brain injury.
Mitchell, Claire; Bowen, Audrey; Tyson, Sarah; Butterfint, Zoe; Conroy, Paul
2017-01-25
Dysarthria is an acquired speech disorder following neurological injury that reduces intelligibility of speech due to weak, imprecise, slow and/or unco-ordinated muscle control. The impact of dysarthria goes beyond communication and affects psychosocial functioning. This is an update of a review previously published in 2005. The scope has been broadened to include additional interventions, and the title amended accordingly. To assess the effects of interventions to improve dysarthric speech following stroke and other non-progressive adult-acquired brain injury such as trauma, infection, tumour and surgery. We searched the Cochrane Stroke Group Trials Register (May 2016), CENTRAL (Cochrane Library 2016, Issue 4), MEDLINE, Embase, and CINAHL on 6 May 2016. We also searched Linguistics and Language Behavioral Abstracts (LLBA) (1976 to November 2016) and PsycINFO (1800 to September 2016). To identify further published, unpublished and ongoing trials, we searched major trials registers: WHO ICTRP, the ISRCTN registry, and ClinicalTrials.gov. We also handsearched the reference lists of relevant articles and contacted academic institutions and other researchers regarding other published, unpublished or ongoing trials. We did not impose any language restrictions. We selected randomised controlled trials (RCTs) comparing dysarthria interventions with 1) no intervention, 2) another intervention for dysarthria (this intervention may differ in methodology, timing of delivery, duration, frequency or theory), or 3) an attention control. Three review authors selected trials for inclusion, extracted data, and assessed risk of bias. We attempted to contact study authors for clarification and missing data as required. We calculated standardised mean difference (SMD) and 95% confidence interval (CI), using a random-effects model, and performed sensitivity analyses to assess the influence of methodological quality. We planned to conduct subgroup analyses for underlying clinical conditions. We included five small trials that randomised a total of 234 participants. Two studies were assessed as low risk of bias; none of the included studies were adequately powered. Two studies used an attention control and three studies compared to an alternative intervention, which in all cases was one intervention versus usual care intervention. The searches we carried out did not find any trials comparing an intervention with no intervention. The searches did not find any trials of an intervention that compared variations in timing, dose, or intensity of treatment using the same intervention. Four studies included only people with stroke; one included mostly people with stroke, but also those with brain injury. Three studies delivered interventions in the first few months after stroke; two recruited people with chronic dysarthria. Three studies evaluated behavioural interventions, one investigated acupuncture and another transcranial magnetic stimulation. One study included people with dysarthria within a broader trial of people with impaired communication.Our primary analysis of a persisting (three to nine months post-intervention) effect at the activity level of measurement found no evidence in favour of dysarthria intervention compared with any control (SMD 0.18, 95% CI -0.18 to 0.55; 3 trials, 116 participants, GRADE: low quality, I² = 0%). Findings from sensitivity analysis of studies at low risk of bias were similar, with a slightly wider confidence interval and low heterogeneity (SMD 0.21, 95% CI -0.30 to 0.73, I² = 32%; 2 trials, 92 participants, GRADE: low quality). Subgroup analysis results for stroke were similar to the primary analysis because few non-stroke participants had been recruited to trials (SMD 0.16, 95% CI -0.23 to 0.54, I² = 0%; 3 trials, 106 participants, GRADE: low quality).Similar results emerged from most of the secondary analyses. There was no evidence of a persisting effect at the impairment (SMD 0.07, 95% CI -0.91 to 1.06, I² = 70%; 2 trials, 56 participants, GRADE: very low quality) or participation level (SMD -0.11, 95% CI -0.56 to 0.33, I² = 0%; 2 trials, 79 participants, GRADE: low quality) but substantial heterogeneity on the former. Analyses of immediate post-intervention outcomes provided no evidence of any short-term benefit on activity (SMD 0.29, 95% CI -0.07 to 0.66, I² = 0%; 3 trials, 117 participants, GRADE: very low quality); or participation (SMD -0.24, 95% CI -0.94 to 0.45; 1 study, 32 participants) levels of measurement.There was a statistically significant effect favouring intervention at the immediate, impairment level of measurement (SMD 0.47, 95% CI 0.02 to 0.92, P = 0.04, I² = 0%; 4 trials, 99 participants, GRADE: very low quality) but only one of these four trials had a low risk of bias. We found no definitive, adequately powered RCTs of interventions for people with dysarthria. We found limited evidence to suggest there may be an immediate beneficial effect on impairment level measures; more, higher quality research is needed to confirm this finding.Although we evaluated five studies, the benefits and risks of interventions remain unknown and the emerging evidence justifies the need for adequately powered clinical trials into this condition.People with dysarthria after stroke or brain injury should continue to receive rehabilitation according to clinical guidelines.
Coronado-Montoya, Stephanie; Levis, Alexander W; Kwakkenbos, Linda; Steele, Russell J; Turner, Erick H; Thombs, Brett D
2016-01-01
A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses. 108 (87%) of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88%) concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7). Of 21 trial registrations, 13 (62%) remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases. The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.
Breeman, S; Campbell, M K; Dakin, H; Fiddian, N; Fitzpatrick, R; Grant, A; Gray, A; Johnston, L; MacLennan, G S; Morris, R W; Murray, D W
2013-04-01
There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery. There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs. In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.
Translation failure and medical reversal: Two sides to the same coin.
Prasad, Vinay
2016-01-01
Translation failure occurs when the results of preclinical, observational and/or early phase studies fail to predict the results of well done (i.e. appropriately controlled, adequately powered, and properly conducted) phase III or randomised clinical trials. Some failures occur when promising basic science findings fail to replicate in human studies, while others happen when promising uncontrolled trial data show an exaggerated effect that vanishes in the setting of a randomised trial. Medical reversals occur when the results of preclinical, observational and/or early phase studies fail to predict the results of subsequent randomized clinical trials, but the practice has already gained widespread acceptance. Oncologic examples include bevacizumab and the use of autologous stem cell transplant in metastatic breast cancer. In a well-intentioned effort to reduce the rate of translation failure, oncologists must be careful that changes to regulatory processes and clinical trial design do not actually work to increase the approval of ineffective compounds. By trying to cure translation failure, we should be careful to avoid medical reversal. The rise of surrogate end-points and role of hard-wired bias in oncology trials suggest that we may be currently ignoring the simple fact that translation failure and medical reversal are two sides to the same coin. Published by Elsevier Ltd.
Osser, David N; Roudsari, Mohsen Jalali; Manschreck, Theo
2013-01-01
This article is an update of the algorithm for schizophrenia from the Psychopharmacology Algorithm Project at the Harvard South Shore Program. A literature review was conducted focusing on new data since the last published version (1999-2001). The first-line treatment recommendation for new-onset schizophrenia is with amisulpride, aripiprazole, risperidone, or ziprasidone for four to six weeks. In some settings the trial could be shorter, considering that evidence of clear improvement with antipsychotics usually occurs within the first two weeks. If the trial of the first antipsychotic cannot be completed due to intolerance, try another until one of the four is tolerated and given an adequate trial. There should be evidence of bioavailability. If the response to this adequate trial is unsatisfactory, try a second monotherapy. If the response to this second adequate trial is also unsatisfactory, and if at least one of the first two trials was with risperidone, olanzapine, or a first-generation (typical) antipsychotic, then clozapine is recommended for the third trial. If neither trial was with any these three options, a third trial prior to clozapine should occur, using one of those three. If the response to monotherapy with clozapine (with dose adjusted by using plasma levels) is unsatisfactory, consider adding risperidone, lamotrigine, or ECT. Beyond that point, there is little solid evidence to support further psychopharmacological treatment choices, though we do review possible options.
Gold, Diane R; Litonjua, Augusto A.; Carey, Vincent J.; Manson, JoAnn E.; Buring, Julie E; Lee, I-Min; Gordon, David; Walter, Joseph; Friedenberg, Georgina; Hankinson, John L; Copeland, Trisha; Luttmann-Gibson, Heike
2016-01-01
Laboratory and observational research studies suggest that vitamin D and marine omega-3 fatty acids may reduce risk for pneumonia, acute exacerbations of respiratory diseases including chronic obstructive lung disease (COPD) or asthma, and decline of lung function, but prevention trials with adequate dosing, adequate power, and adequate time to follow-up are lacking. The ongoing Lung VITAL study is taking advantage of a large clinical trial—the VITamin D and OmegA-3 TriaL (VITAL)—to conduct the first major evaluation of the influences of vitamin D and marine omega-3 fatty acid supplementation on pneumonia risk, respiratory exacerbation episodes, asthma control and lung function in adults. VITAL is a 5-year U.S.-wide randomized, double-blind, placebo-controlled, 2×2 factorial trial of supplementation with vitamin D3 ([cholecalciferol], 2000 IU/day) and marine omega-3 FA (Omacor® fish oil, eicosapentaenoic acid [EPA] +docosahexaenoic acid [DHA], 1 g/day) for primary prevention of CVD and cancer among men and women, at baseline aged ≥50 and ≥55, respectively, with 5107 African Americans. In a subset of 1973 participants from 11 urban U.S. centers, lung function is measured before and two years after randomization. Yearly follow-up questionnaires assess incident pneumonia in the entire randomized population, and exacerbations of respiratory disease, asthma control and dyspnea in a subpopulation of 4314 randomized participants enriched, as shown in presentation of baseline characteristics, for respiratory disease, respiratory symptoms, and history of cigarette smoking. Self-reported pneumonia hospitalization will be confirmed by medical record review, and exacerbations will be confirmed by Center for Medicare and Medicaid Services data review. PMID:26784651
Zhai, Xiao; Wang, Yiran; Mu, Qingchun; Chen, Xiao; Huang, Qin; Wang, Qijin; Li, Ming
2015-07-01
To appraise the current reporting methodological quality of randomized clinical trials (RCTs) in 3 leading diabetes journals.We systematically searched the literature for RCTs in Diabetes Care, Diabetes and Diabetologia from 2011 to 2013.Characteristics were extracted based on Consolidated Standards of Reporting Trials (CONSORT) statement. Generation of allocation, concealment of allocation, intention-to-treat (ITT) analysis and handling of dropouts were defined as primary outcome and "low risk of bias." Sample size calculation, type of intervention, country, number of patients, funding source were also revealed and descriptively reported. Trials were compared among journals, study years, and other characters.A total of 305 RCTs were enrolled in this study. One hundred eight (35.4%) trials reported adequate generation of allocation, 87 (28.5%) trials reported adequate concealment of allocation, 53 (23.8%) trials used ITT analysis, and 130 (58.3%) trials were adequate in handling of dropouts. Only 15 (4.9%) were "low risk of bias" trials. Studies at a large scale (n > 100) or from European presented with more "low risk of bias" trials than those at a small scale (n ≤ 100) or from other regions. No improvements were found in these 3 years.This study shows that methodological reporting quality of RCTs in the major diabetes journals remains suboptimal. It can be further improved to meet and keep up with the standards of the CONSORT statement.
Zhang, Xinji; Zhang, Yuan; Ye, Xiaofei; Guo, Xiaojing; Zhang, Tianyi; He, Jia
2016-11-23
Phase IV trials are often used to investigate drug safety after approval. However, little is known about the characteristics of contemporary phase IV clinical trials and whether these studies are of sufficient quality to advance medical knowledge in pharmacovigilance. We aimed to determine the fundamental characteristics of phase IV clinical trials that evaluated drug safety using the ClinicalTrials.gov registry data. A data set of 19 359 phase IV clinical studies registered in ClinicalTrials.gov was downloaded. The characteristics of the phase IV trials focusing on safety only were compared with those evaluating both safety and efficacy. We also compared the characteristics of the phase IV trials in three major therapeutic areas (cardiovascular diseases, mental health and oncology). Multivariable logistic regression was used to evaluate factors associated with the use of blinding and randomisation. A total of 4772 phase IV trials were identified, including 330 focusing on drug safety alone and 4392 evaluating both safety and efficacy. Most of the phase IV trials evaluating drug safety (75.9%) had enrolment <300 with 96.5% <3000. Among these trials, 8.2% were terminated or withdrawn. Factors associated with the use of blinding and randomisation included the intervention model, clinical specialty and lead sponsor. Phase IV trials evaluating drug safety in the ClinicalTrials.gov registry were dominated by small trials that might not have sufficient power to detect less common adverse events. An adequate sample size should be emphasised for phase IV trials with safety surveillance as main task. 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/.
Donnelly, Joseph E; Herrmann, Stephen D; Lambourne, Kate; Szabo, Amanda N; Honas, Jeffery J; Washburn, Richard A
2014-01-01
The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. TO ADDRESS THE QUESTION: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? PubMed and Embase were searched (January 1990-January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18-64 years). Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake.
El Senoun, Ghada Abou; Dowswell, Therese; Mousa, Hatem A
2014-01-01
Background Preterm prelabour rupture of membranes (PPROM) is associated with increased risk of maternal and neonatal morbidity and mortality. Women with PPROM have been predominantly managed in hospital. It is possible that selected women could be managed at home after a period of observation. The safety, cost and women’s views about home management have not been established. Objectives To assess the safety, cost and women’s views about planned home versus hospital care for women with PPROM. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (January 2010) and the reference lists of all the identified articles. Selection criteria Randomised and quasi-randomised trials comparing planned home versus hospital management for women with PPROM before 37 weeks’ gestation. Data collection and analysis Two review authors independently assessed clinical trials for eligibility for inclusion, risk of bias, and carried out data extraction. Main results We included two trials (116 women) comparing planned home versus hospital management for PPROM. Overall, the number of included women in each trial was too small to allow adequate assessment of pre-specified outcomes. Investigators used strict inclusion criteria and in both studies relatively few of the women presenting with PPROM were eligible for inclusion. Women were monitored for 48 to 72 hours before randomisation. Perinatal mortality was reported in one trial and there was insufficient evidence to determine whether it differed between the two groups (risk ratio (RR) 1.93, 95% confidence interval (CI) 0.19 to 20.05). There was no evidence of differences between groups for serious neonatal morbidity, chorioamnionitis, gestational age at delivery, birthweight and admission to neonatal intensive care. There was no information on serious maternal morbidity or mortality. There was some evidence that women managed in hospital were more likely to be delivered by caesarean section (RR (random-effects) 0.28, 95% CI 0.07 to 1.15). However, results should be interpreted cautiously as there is a moderate heterogeneity for this outcome (I2 = 35%). Mothers randomised to care at home spent approximately 10 fewer days as inpatients (mean difference −9.60, 95% CI −14.59 to −4.61) and were more satisfied with their care. Furthermore, home care was associated with reduced costs. Authors’ conclusions The review included two relatively small studies that did not have sufficient statistical power to detect meaningful differences between groups. Future large and adequately powered randomised controlled trials are required to measure differences between groups for relevant pre-specified outcomes. Special attention should be given to the assessment of maternal satisfaction with care and cost analysis as they will have social and economic implications in both developed and developing countries. PMID:20393965
Abou El Senoun, Ghada; Dowswell, Therese; Mousa, Hatem A
2010-04-14
Preterm prelabour rupture of membranes (PPROM) is associated with increased risk of maternal and neonatal morbidity and mortality. Women with PPROM have been predominantly managed in hospital. It is possible that selected women could be managed at home after a period of observation. The safety, cost and women's views about home management have not been established. To assess the safety, cost and women's views about planned home versus hospital care for women with PPROM. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2010) and the reference lists of all the identified articles. Randomised and quasi-randomised trials comparing planned home versus hospital management for women with PPROM before 37 weeks' gestation. Two review authors independently assessed clinical trials for eligibility for inclusion, risk of bias, and carried out data extraction. We included two trials (116 women) comparing planned home versus hospital management for PPROM. Overall, the number of included women in each trial was too small to allow adequate assessment of pre-specified outcomes. Investigators used strict inclusion criteria and in both studies relatively few of the women presenting with PPROM were eligible for inclusion. Women were monitored for 48 to 72 hours before randomisation. Perinatal mortality was reported in one trial and there was insufficient evidence to determine whether it differed between the two groups (risk ratio (RR) 1.93, 95% confidence interval (CI) 0.19 to 20.05). There was no evidence of differences between groups for serious neonatal morbidity, chorioamnionitis, gestational age at delivery, birthweight and admission to neonatal intensive care.There was no information on serious maternal morbidity or mortality. There was some evidence that women managed in hospital were more likely to be delivered by caesarean section (RR (random-effects) 0.28, 95% CI 0.07 to 1.15). However, results should be interpreted cautiously as there is a moderate heterogeneity for this outcome (I(2) = 35%). Mothers randomised to care at home spent approximately 10 fewer days as inpatients (mean difference -9.60, 95% CI -14.59 to -4.61) and were more satisfied with their care. Furthermore, home care was associated with reduced costs. The review included two relatively small studies that did not have sufficient statistical power to detect meaningful differences between groups. Future large and adequately powered randomised controlled trials are required to measure differences between groups for relevant pre-specified outcomes. Special attention should be given to the assessment of maternal satisfaction with care and cost analysis as they will have social and economic implications in both developed and developing countries.
Abou El Senoun, Ghada; Dowswell, Therese; Mousa, Hatem A
2014-04-14
Preterm prelabour rupture of membranes (PPROM) is associated with increased risk of maternal and neonatal morbidity and mortality. Women with PPROM have been predominantly managed in hospital. It is possible that selected women could be managed at home after a period of observation. The safety, cost and women's views about home management have not been established. To assess the safety, cost and women's views about planned home versus hospital care for women with PPROM. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2013) and the reference lists of all the identified articles. Randomised and quasi-randomised trials comparing planned home versus hospital management for women with PPROM before 37 weeks' gestation. Two review authors independently assessed clinical trials for eligibility for inclusion, risk of bias, and carried out data extraction. We included two trials (116 women) comparing planned home versus hospital management for PPROM. Overall, the number of included women in each trial was too small to allow adequate assessment of pre-specified outcomes. Investigators used strict inclusion criteria and in both studies relatively few of the women presenting with PPROM were eligible for inclusion. Women were monitored for 48 to 72 hours before randomisation. Perinatal mortality was reported in one trial and there was insufficient evidence to determine whether it differed between the two groups (risk ratio (RR) 1.93, 95% confidence interval (CI) 0.19 to 20.05). There was no evidence of differences between groups for serious neonatal morbidity, chorioamnionitis, gestational age at delivery, birthweight and admission to neonatal intensive care.There was no information on serious maternal morbidity or mortality. There was some evidence that women managed in hospital were more likely to be delivered by caesarean section (RR (random-effects) 0.28, 95% CI 0.07 to 1.15). However, results should be interpreted cautiously as there is moderate heterogeneity for this outcome (I² = 35%). Mothers randomised to care at home spent approximately 10 fewer days as inpatients (mean difference -9.60, 95% CI -14.59 to -4.61) and were more satisfied with their care. Furthermore, home care was associated with reduced costs. The review included two relatively small studies that did not have sufficient statistical power to detect meaningful differences between groups. Future large and adequately powered randomised controlled trials are required to measure differences between groups for relevant pre-specified outcomes. Special attention should be given to the assessment of maternal satisfaction with care and cost analysis as they will have social and economic implications in both developed and developing countries.
Cuzick, Jack; Cafferty, Fay H; Edwards, Robert; Møller, Henrik; Duffy, Stephen W
2007-01-01
Cancer screening is aimed primarily at reducing deaths. Thus, site-specific cancer mortality is the appropriate endpoint for evaluating screening interventions. However, it is also the most demanding endpoint, requiring follow-up and a large numbers of patients order to have adequate power. Therefore, it is highly desirable to have surrogate endpoints that can reliably predict mortality reductions many years earlier. We here review a range of surrogate markers in terms of their potential advantages and pitfalls, and argue that a measure which weights incident cancers according to their predicted mortality has many advantages over other measures and should be used more routinely. Application to the UK Flexible Sigmoidoscopy Screening Trial data suggests that predicted colorectal cancer mortality, based on stage-specific incidence, is a more powerful endpoint than actual mortality and could advance the analysis time by about three years. Total colorectal cancer incidence as a surrogate endpoint provides little advance in the analysis time over actual mortality. The approach requires reliable prognostic data, (e.g. stage), for both the study cohort and a representative sample of the whole population. The routine collection of such data should be a priority for cancer registries. Surrogate endpoints should not replace a long-term analysis based directly on mortality, but can provide reliable early indicators which can be useful both for monitoring ongoing screening programmes and for making policy decisions.
Stamenovic, Milorad; Dobraca, Amra; Smajlovic, Mersiha
2018-01-01
The aim of this paper is to present the marketing strategy and the application of management (marketing management) and advertising in order to increase the efficiency of innovative approach in clinical trials that include and involve the use of new technologies and transfer of technologies. This paper has a descriptive character and represents a narrative review of the literature and new model implementation. Marketing models are primarily used to improve the inclusion of a larger (and appropriate) number of patients, but they can be credited for the stay and monitoring of patients in the trial. Regulatory mechanisms play an important role in the application of various marketing strategies within clinical trials. The value for the patient as the most important stakeholder is defined in the field of clinical trials according to Kotler's value model for the consumer. In order to achieve the best results it is important to adequately examine all the elements of clinical trials and apply this knowledge in creation of a marketing plan that will be made in accordance with the legal regulations defined globally and locally. In this paper, two challenges have been highlighted for the adequate application of marketing tools in the field of clinical trials, namely: defining business elements in order to provide an adequate marketing approach for clinical trials and technology transfer and ensuring uniformity and regulatory affirmation of marketing attitudes in clinical trials in all regions in which they are carried out in accordance with ICH-GCP and valid regulations.
Doros, Gheorghe; Pencina, Michael; Rybin, Denis; Meisner, Allison; Fava, Maurizio
2013-07-20
Previous authors have proposed the sequential parallel comparison design (SPCD) to address the issue of high placebo response rate in clinical trials. The original use of SPCD focused on binary outcomes, but recent use has since been extended to continuous outcomes that arise more naturally in many fields, including psychiatry. Analytic methods proposed to date for analysis of SPCD trial continuous data included methods based on seemingly unrelated regression and ordinary least squares. Here, we propose a repeated measures linear model that uses all outcome data collected in the trial and accounts for data that are missing at random. An appropriate contrast formulated after the model has been fit can be used to test the primary hypothesis of no difference in treatment effects between study arms. Our extensive simulations show that when compared with the other methods, our approach preserves the type I error even for small sample sizes and offers adequate power and the smallest mean squared error under a wide variety of assumptions. We recommend consideration of our approach for analysis of data coming from SPCD trials. Copyright © 2013 John Wiley & Sons, Ltd.
The art and science of choosing efficacy endpoints for rare disease clinical trials.
Cox, Gerald F
2018-04-01
An important challenge in rare disease clinical trials is to demonstrate a clinically meaningful and statistically significant response to treatment. Selecting the most appropriate and sensitive efficacy endpoints for a treatment trial is part art and part science. The types of endpoints should align with the stage of development (e.g., proof of concept vs. confirmation of clinical efficacy). The patient characteristics and disease stage should reflect the treatment goal of improving disease manifestations or preventing disease progression. For rare diseases, regulatory approval requires demonstration of clinical benefit, defined as how a patient, feels, functions, or survives, in at least one adequate and well-controlled pivotal study conducted according to Good Clinical Practice. In some cases, full regulatory approval can occur using a validated surrogate biomarker, while accelerated, or provisional, approval can occur using a biomarker that is likely to predict clinical benefit. Rare disease studies are small by necessity and require the use of endpoints with large effect sizes to demonstrate statistical significance. Understanding the quantitative factors that determine effect size and its impact on powering the study with an adequate sample size is key to the successful choice of endpoints. Interpreting the clinical meaningfulness of an observed change in an efficacy endpoint can be justified by statistical methods, regulatory precedence, and clinical context. Heterogeneous diseases that affect multiple organ systems may be better accommodated by endpoints that assess mean change across multiple endpoints within the same patient rather than mean change in an individual endpoint across all patients. © 2018 Wiley Periodicals, Inc.
Systematic Review of Plant-Based Homeopathic Basic Research: An Update.
Ücker, Annekathrin; Baumgartner, Stephan; Sokol, Anezka; Huber, Roman; Doesburg, Paul; Jäger, Tim
2018-05-01
Plant-based test systems have been described as a useful tool for investigating possible effects of homeopathic preparations. The last reviews of this research field were published in 2009/2011. Due to recent developments in the field, an update is warranted. Publications on plant-based test systems were analysed with regard to publication quality, reproducibility and potential for further research. A literature search was conducted in online databases and specific journals, including publications from 2008 to 2017 dealing with plant-based test systems in homeopathic basic research. To be included, they had to contain statistical analysis and fulfil quality criteria according to a pre-defined manuscript information score (MIS). Publications scoring at least 5 points (maximum 10 points) were assumed to be adequate. They were analysed for the use of adequate controls, outcome and reproducibility. Seventy-four publications on plant-based test systems were found. Thirty-nine publications were either abstracts or proceedings of conferences and were excluded. From the remaining 35 publications, 26 reached a score of 5 or higher in the MIS. Adequate controls were used in 13 of these publications. All of them described specific effects of homeopathic preparations. The publication quality still varied: a substantial number of publications (23%) did not adequately document the methods used. Four reported on replication trials. One replication trial found effects of homeopathic preparations comparable to the original study. Three replication trials failed to confirm the original study but identified possible external influencing factors. Five publications described novel plant-based test systems. Eight trials used systematic negative control experiments to document test system stability. Regarding research design, future trials should implement adequate controls to identify specific effects of homeopathic preparations and include systematic negative control experiments. Further external and internal replication trials, and control of influencing factors, are needed to verify results. Standardised test systems should be developed. The Faculty of Homeopathy.
Neuropharmacology of Poststroke Motor and Speech Recovery.
Keser, Zafer; Francisco, Gerard E
2015-11-01
Almost 7 million adult Americans have had a stroke. There is a growing need for more effective treatment options as add-ons to conventional therapies. This article summarizes the published literature for pharmacologic agents used for the enhancement of motor and speech recovery after stroke. Amphetamine, levodopa, selective serotonin reuptake inhibitors, and piracetam were the most commonly used drugs. Pharmacologic augmentation of stroke motor and speech recovery seems promising but systematic, adequately powered, randomized, and double-blind clinical trials are needed. At this point, the use of these pharmacologic agents is not supported by class I evidence. Copyright © 2015 Elsevier Inc. All rights reserved.
Sickle cell disease and venous thromboembolism in pregnancy and the puerperium.
Noubouossie, Denis; Key, Nigel S
2015-02-01
Recent data strongly suggest an increased risk of venous thromboembolism in subjects with sickle cell disease and to a lesser extent, sickle cell trait. However, most studies have been retrospective, case-control or cross-sectional based on data obtained from administrative databases. More data from adequately powered prospective studies that include matched controls are needed to definitely establish the link between venous thromboembolism during pregnancy and sickle hemoglobin disorders. Similarly, there remains a need for properly designed randomized control trials to establish the safety of various hormonal contraceptive methods in women with sickle cell disorders. © 2015 Elsevier Ltd. All rights reserved.
Catheter ablation in patients with persistent atrial fibrillation
Kirchhof, Paulus; Calkins, Hugh
2017-01-01
Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited. Pulmonary vein isolation is a reasonable and effective first approach for catheter ablation of persistent AF. Other ablation strategies are being developed and need to be properly evaluated in controlled, multicentre trials. Treatment of concomitant conditions promoting recurrent AF by life style interventions and medical therapy should be a routine adjunct to catheter ablation of persistent AF. Early rhythm control therapy has a biological rationale and trials evaluating its value are underway. There is a clear need to generate more evidence for the best approach to ablation of persistent AF beyond pulmonary vein isolation in the form of adequately powered controlled multi-centre trials. PMID:27389907
Elsas, S M; Gregory, W L; White, G; Navarro, G; Salinsky, M C; Andrews, D J
2011-12-01
Patients with epilepsy frequently experience depression and emotional stress and these may function as seizure triggers in epileptogenic frontotemporal cortex, which serves in emotional processing. Eight patients enrolled in a pilot trial of a 6-month epilepsy-specific behavioral approach comprising counseling and relaxation to recognize and eliminate emotional seizure triggers. Potential participants with psychogenic seizures were excluded by long-term EEG and/or the MMPI profile. One participant became seizure free, another had an approximately 90% reduction in seizures, and two additional participants achieved a greater than 50% reduction in seizure frequency (total responder rate=50%), stable during 6 months of observation after the intervention. All completers showed marked and stable improvement of quality of life (Quality of Life in Epilepsy-89 inventory) and temporary improvement in the Profile of Mood States. An adequately powered randomized controlled trial is needed to confirm our findings, which suggest that behavioral approaches may hold promise for motivated patients with epilepsy. Copyright © 2011 Elsevier Inc. All rights reserved.
Cardiovascular safety of biologic therapies for the treatment of RA.
Greenberg, Jeffrey D; Furer, Victoria; Farkouh, Michael E
2011-11-15
Cardiovascular disease represents a major source of extra-articular comorbidity in patients with rheumatoid arthritis (RA). A combination of traditional cardiovascular risk factors and RA-related factors accounts for the excess risk in RA. Among RA-related factors, chronic systemic inflammation has been implicated in the pathogenesis and progression of atherosclerosis. A growing body of evidence--mainly derived from observational databases and registries--suggests that specific RA therapies, including methotrexate and anti-TNF biologic agents, can reduce the risk of future cardiovascular events in patients with RA. The cardiovascular profile of other biologic therapies for the treatment of RA has not been adequately studied, including of investigational drugs that improve systemic inflammation but alter traditional cardiovascular risk factors. In the absence of large clinical trials adequately powered to detect differences in cardiovascular events between biologic drugs in RA, deriving firm conclusions on cardiovascular safety is challenging. Nevertheless, observational research using large registries has emerged as a promising approach to study the cardiovascular risk of emerging RA biologic therapies.
Free, Caroline; Phillips, Gemma; Galli, Leandro; Watson, Louise; Felix, Lambert; Edwards, Phil; Patel, Vikram; Haines, Andy
2013-01-01
Mobile technologies could be a powerful media for providing individual level support to health care consumers. We conducted a systematic review to assess the effectiveness of mobile technology interventions delivered to health care consumers. We searched for all controlled trials of mobile technology-based health interventions delivered to health care consumers using MEDLINE, EMBASE, PsycINFO, Global Health, Web of Science, Cochrane Library, UK NHS HTA (Jan 1990-Sept 2010). Two authors extracted data on allocation concealment, allocation sequence, blinding, completeness of follow-up, and measures of effect. We calculated effect estimates and used random effects meta-analysis. We identified 75 trials. Fifty-nine trials investigated the use of mobile technologies to improve disease management and 26 trials investigated their use to change health behaviours. Nearly all trials were conducted in high-income countries. Four trials had a low risk of bias. Two trials of disease management had low risk of bias; in one, antiretroviral (ART) adherence, use of text messages reduced high viral load (>400 copies), with a relative risk (RR) of 0.85 (95% CI 0.72-0.99), but no statistically significant benefit on mortality (RR 0.79 [95% CI 0.47-1.32]). In a second, a PDA based intervention increased scores for perceived self care agency in lung transplant patients. Two trials of health behaviour management had low risk of bias. The pooled effect of text messaging smoking cessation support on biochemically verified smoking cessation was (RR 2.16 [95% CI 1.77-2.62]). Interventions for other conditions showed suggestive benefits in some cases, but the results were not consistent. No evidence of publication bias was demonstrated on visual or statistical examination of the funnel plots for either disease management or health behaviours. To address the limitation of the older search, we also reviewed more recent literature. Text messaging interventions increased adherence to ART and smoking cessation and should be considered for inclusion in services. Although there is suggestive evidence of benefit in some other areas, high quality adequately powered trials of optimised interventions are required to evaluate effects on objective outcomes.
Azar, Marleine; Riehm, Kira E.; McKay, Dean; Thombs, Brett D.
2015-01-01
Background Confidence that randomized controlled trial (RCT) results accurately reflect intervention effectiveness depends on proper trial conduct and the accuracy and completeness of published trial reports. The Journal of Consulting and Clinical Psychology (JCCP) is the primary trials journal amongst American Psychological Association (APA) journals. The objectives of this study were to review RCTs recently published in JCCP to evaluate (1) adequacy of primary outcome analysis definitions; (2) registration status; and, (3) among registered trials, adequacy of outcome registrations. Additionally, we compared results from JCCP to findings from a recent study of top psychosomatic and behavioral medicine journals. Methods Eligible RCTs were published in JCCP in 2013–2014. For each RCT, two investigators independently extracted data on (1) adequacy of outcome analysis definitions in the published report, (2) whether the RCT was registered prior to enrolling patients, and (3) adequacy of outcome registration. Results Of 70 RCTs reviewed, 12 (17.1%) adequately defined primary or secondary outcome analyses, whereas 58 (82.3%) had multiple primary outcome analyses without statistical adjustment or undefined outcome analyses. There were 39 (55.7%) registered trials. Only two trials registered prior to patient enrollment with a single primary outcome variable and time point of assessment. However, in one of the two trials, registered and published outcomes were discrepant. No studies were adequately registered as per Standard Protocol Items: Recommendation for Interventional Trials guidelines. Compared to psychosomatic and behavioral medicine journals, the proportion of published trials with adequate outcome analysis declarations was significantly lower in JCCP (17.1% versus 32.9%; p = 0.029). The proportion of registered trials in JCCP (55.7%) was comparable to behavioral medicine journals (52.6%; p = 0.709). Conclusions The quality of published outcome analysis definitions and trial registrations in JCCP is suboptimal. Greater attention to proper trial registration and outcome analysis definition in published reports is needed. PMID:26581079
Azar, Marleine; Riehm, Kira E; McKay, Dean; Thombs, Brett D
2015-01-01
Confidence that randomized controlled trial (RCT) results accurately reflect intervention effectiveness depends on proper trial conduct and the accuracy and completeness of published trial reports. The Journal of Consulting and Clinical Psychology (JCCP) is the primary trials journal amongst American Psychological Association (APA) journals. The objectives of this study were to review RCTs recently published in JCCP to evaluate (1) adequacy of primary outcome analysis definitions; (2) registration status; and, (3) among registered trials, adequacy of outcome registrations. Additionally, we compared results from JCCP to findings from a recent study of top psychosomatic and behavioral medicine journals. Eligible RCTs were published in JCCP in 2013-2014. For each RCT, two investigators independently extracted data on (1) adequacy of outcome analysis definitions in the published report, (2) whether the RCT was registered prior to enrolling patients, and (3) adequacy of outcome registration. Of 70 RCTs reviewed, 12 (17.1%) adequately defined primary or secondary outcome analyses, whereas 58 (82.3%) had multiple primary outcome analyses without statistical adjustment or undefined outcome analyses. There were 39 (55.7%) registered trials. Only two trials registered prior to patient enrollment with a single primary outcome variable and time point of assessment. However, in one of the two trials, registered and published outcomes were discrepant. No studies were adequately registered as per Standard Protocol Items: Recommendation for Interventional Trials guidelines. Compared to psychosomatic and behavioral medicine journals, the proportion of published trials with adequate outcome analysis declarations was significantly lower in JCCP (17.1% versus 32.9%; p = 0.029). The proportion of registered trials in JCCP (55.7%) was comparable to behavioral medicine journals (52.6%; p = 0.709). The quality of published outcome analysis definitions and trial registrations in JCCP is suboptimal. Greater attention to proper trial registration and outcome analysis definition in published reports is needed.
Stamenovic, Milorad; Dobraca, Amra; Smajlovic, Mersiha
2018-01-01
Introduction: The aim of this paper is to present the marketing strategy and the application of management (marketing management) and advertising in order to increase the efficiency of innovative approach in clinical trials that include and involve the use of new technologies and transfer of technologies. Material and Methods: This paper has a descriptive character and represents a narrative review of the literature and new model implementation. Results: Marketing models are primarily used to improve the inclusion of a larger (and appropriate) number of patients, but they can be credited for the stay and monitoring of patients in the trial. Regulatory mechanisms play an important role in the application of various marketing strategies within clinical trials. The value for the patient as the most important stakeholder is defined in the field of clinical trials according to Kotler’s value model for the consumer. Conclusion: In order to achieve the best results it is important to adequately examine all the elements of clinical trials and apply this knowledge in creation of a marketing plan that will be made in accordance with the legal regulations defined globally and locally. In this paper, two challenges have been highlighted for the adequate application of marketing tools in the field of clinical trials, namely: defining business elements in order to provide an adequate marketing approach for clinical trials and technology transfer and ensuring uniformity and regulatory affirmation of marketing attitudes in clinical trials in all regions in which they are carried out in accordance with ICH-GCP and valid regulations. PMID:29719318
Selenium and glutamine supplements: where are we heading? A critical care perspective.
Andrews, Peter J D
2010-03-01
There is considerable interest in glutamine and selenium in critical care as both offer the potential to enhance host defences, through different but complimentary mechanisms and may reduce subsequent infections and mortality. The SIGNET trial (randomized controlled factorial trial) is the largest, critical care study of both supplements. The data have been presented publicly, but the data are not published or available for review and will therefore not be discussed fully in this update. In the present review I will explore the recently available (past 1-2 years) published literature. The current literature demonstrates that there are currently insufficient data to enable confident recommendations on the optimal route, timing, duration and dosage of each of these nutritional supplements. The pending results of SIGNET, the largest critical care trial of parenteral nutrition supplemented by glutamine and or selenium promises to clarify some of the current ambiguities and inform future practice. To be able to confidently establish or refute the hypothesis that either glutamine or selenium alone or in combination improves outcome in critical care requires a well designed prospective randomized controlled trial. To design such a trial we require the optimal dose and duration of the nutritional supplement (balancing efficacy and toxicity, ease of administration and cost) and then conduct an adequately powered trial. Such a trial is still lacking for these two agents. There are some supportive data for selenium but the case is less strong for parenteral glutamine and weakest for enteral glutamine.
High-dose transdermal nicotine replacement for tobacco cessation.
Brokowski, Laurie; Chen, Jiahui; Tanner, Sara
2014-04-15
The safety and efficacy of high-dose transdermal nicotine-replacement therapy (NRT) for the treatment of tobacco-use cessation were reviewed. Transdermal nicotine doses of 7, 14, and 21 mg daily are approved by the Food and Drug Administration for use in tobacco cessation. However, studies have suggested that these doses are more adequate for people who smoke fewer than 20 cigarettes per day. A literature search was conducted to identify English-language studies that evaluated the use of transdermal nicotine doses of ≥42 mg daily. A total of 11 articles were identified, representing 10 separate trials. In terms of safety, the majority of the trials had no reports of serious adverse events related to transdermal NRT at doses of ≥42 mg daily. A dose-response relationship with adverse events occurred in most trials. In terms of efficacy, a numerically higher abstinence rate was achieved with high-dose transdermal NRT in all trials but 1. However, none of the studies showed significant differences in final abstinence rates at follow-up. Some reasons why statistical significance was not achieved in these trials may be related to the limitations of these trials, such as their small samples and the lack of a power calculation. A more robust trial is needed to support higher nicotine transdermal doses in tobacco cessation and to help elucidate which patient population would be most suitable for their use. The safety and efficacy of high-dose transdermal NRT for tobacco cessation have not been established in the medical literature.
Can pregnant diabetics be treated with glyburide?
Melamed, Nir; Yogev, Yariv
2009-11-01
Until the last decade, oral hypoglycemic agents have not been recommended in pregnancy owing to fear of their potential adverse fetal effects, including teratogenicity and neonatal hypoglycemia. However, the evidence in support of these recommendations is weak and is principally based on case series involving the use of first-generation sulfonylureas. Studies using a single-cotyledon placental model have found glyburide to only minimally cross the placenta, an observation that paved the way for a landmark randomized clinical trial that found glyburide to be as safe and effective as insulin in the management of gestational diabetes mellitus. Still, contradicting results regarding its trans-placental transfer, lack of adequate data regarding its safety during the first trimester and reports of increased neonatal morbidity raise concerns regarding the universal application of glyburide as an alternative to insulin therapy in diabetic pregnant women. Thus, there is a need for large, randomized, controlled trials with adequate power to evaluate the possibility of increased neonatal metabolic complications as well as the long-term outcome of infants born to mothers treated with glyburide and insulin. Unless future studies refute current data regarding the efficacy and safety of glyburide, we believe that, owing to its ease of administration, convenience and low cost, glyburide will become the first line of medical treatment in patients with gestational diabetes mellitus within the next few years.
Probiotic supplementation in children with cystic fibrosis-a systematic review.
Ananthan, Anitha; Balasubramanian, Haribalakrishna; Rao, Shripada; Patole, Sanjay
2016-10-01
Probiotics may benefit in cystic fibrosis (CF) as gut dysbiosis is associated with gastrointestinal symptoms and exacerbation of respiratory symptoms in CF. We conducted a systematic review of randomized controlled trials (RCTs) and non-RCTs of probiotic supplementation in children with CF, using the Cochrane methodology, preferred reporting items for systematic reviews (PRISMA) statement, and meta-analysis of observational studies in epidemiology (MOOSE) guidelines. Primary outcomes were pulmonary exacerbations, duration of hospitalization and antibiotics, and all-cause mortality. Secondary outcomes included gastrointestinal symptoms, markers of gut inflammation, and intestinal microbial balance. A total of nine studies (RCTs, 6, non-RCTs, 3; N = 275) with some methodological weaknesses were included in the review. The pooled estimate showed significant reduction in the rate of pulmonary exacerbation (fixed effects model, two parallel group RCTs and one cross-over trial: relative risk (RR) 0.25, (95 % confidence interval (95 % CI) 0.15,0.41); p < 0.00001; level of evidence: low) and decrease in fecal calprotectin (FCLP) levels (fixed effect model, three RCTs: mean difference (MD) -16.71, 95 % CI -27.30,-6.13); p = 0.002; level of evidence: low) after probiotic supplementation. Probiotic supplementation significantly improved gastrointestinal symptoms (one RCT, one non-RCT) and gut microbial balance (decreased Proteobacteria, increased Firmicutes, and Bacteroides in one RCT, one non-RCT). Limited low-quality evidence exists on the effects of probiotics in children with CF. Well-designed adequately powered RCTs assessing clinically meaningful outcomes are required to study this important issue. • Gut dysbiosis is frequent in children with cystic fibrosis due to frequent exposure to pathogens and antibiotics. • Probiotics decrease gut dysbiosis and improve gut maturity and function. What is New: • This comprehensive systematic review shows that current evidence on the safety and efficacy of probiotics in children with cystic fibrosis is limited and of low quality. • Well-designed and adequately powered trials assessing clinically important outcomes are required considering the health burden of cystic fibrosis and the potential benefits of probiotics.
Hussain, Maha; Tangen, Catherine; Higano, Celestia; Vogelzang, Nicholas; Thompson, Ian
2016-01-20
Intermittent androgen deprivation (IAD) has been widely tested in prostate cancer. However, phase III trials testing continuous androgen deprivation (CAD) versus IAD have reached inconclusive and seemingly contradictory results. Different design and conduct issues must be critically evaluated to better interpret the results. Seven published phase III trials were examined for prespecified design and outcomes. Treatment specifications; primary end point; superiority versus noninferiority design assumptions, including magnitude of assumed versus observed noninferiority margin (NIM); duration of follow-up; and quality-of-life (QOL) outcomes were considered in terms of the results and conclusions reported. Five trials had a superiority and three had a noninferiority primary hypothesis. Only three trials had a uniform population and overall survival (OS) end point. All trials observed better outcomes in terms of OS and progression-free survival (PFS) than assumed at time of study design, translating into prespecified NIMs or hazard ratios that reflected larger absolute differences in OS or PFS between arms. Lower-than-expected event rates also reduced statistical power for the trials. Other factors, including length of follow-up, cause of death, QOL, and primary end point, and their impact on trial interpretation are discussed. No trial to date has demonstrated survival superiority of IAD compared with CAD. Trials concluding IAD is noninferior to CAD were based on wide NIMs that included clinically important survival differences, not likely to be considered comparable by physicians or patients. Interim analyses relying on short follow-up and including a majority of non-prostate cancer deaths will favor a noninferiority conclusion and should be interpreted cautiously. Adequate follow-up is required to ensure capture of prostate cancer deaths in both superiority and noninferiority trials. © 2015 by American Society of Clinical Oncology.
46 CFR 199.110 - Survival craft muster and embarkation arrangements.
Code of Federal Regulations, 2010 CFR
2010-10-01
... be adequately illuminated by lighting with power supplied from the vessel's emergency source of electrical power. (d) Each alleyway, stairway, and exit giving access to a muster and embarkation station must be adequately illuminated by lighting that is capable of having its power supplied by the vessel's...
46 CFR 199.110 - Survival craft muster and embarkation arrangements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... be adequately illuminated by lighting with power supplied from the vessel's emergency source of electrical power. (d) Each alleyway, stairway, and exit giving access to a muster and embarkation station must be adequately illuminated by lighting that is capable of having its power supplied by the vessel's...
Haddad, Cynthia; Sigha, Odette Berline; Lebrun-Vignes, Bénédicte; Chosidow, Olivier; Fardet, Laurence
2017-07-01
Randomized controlled trials (RCTs) are considered the gold standard for assessing efficacy and short-term harm of medicines. However, several studies have come to the conclusion that harm is less well reported than efficacy outcomes. To describe harm reporting in publications on dermatological RCTs and assess parameters that could influence the quality of harm reporting. Methodologic systematic review of dermatologic RCTs published from 2010 to 2014 in 5 dermatological journals. Among 110 assessed publications on RCTs, 80 (73%) adequately reported harm and 52% adequately reported its severity. Overall, 40% of the assessed manuscripts perfectly reported and discussed harm. The adequate reporting of harm was significantly associated with the type of trial (odds ratio [OR] 4.41, 95% confidence interval [CI] 1.60-12.35 for multicenter compared with monocentric trials) and having a predefined method for collecting harm data (OR 5.93, 95% CI 2.26-15.56). Reporting of harm severity was better in pharmacologic trials (OR 6.48, 95% CI 2.00-21.0) compared with nonpharmacologic trials and in trials for which a method for collecting harm (OR 5.65, 95% CI 2.00-16.4) and its severity (OR 3.60, 95% CI 1.00-12.8) was defined before the study onset. Assessment was restricted to RCTs and 5 dermatological journals. Harm is quite well reported in dermatologic journals. Efforts should be made on reporting severity of harm. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.
Cysique, Lucette A; Waters, Edward K; Brew, Bruce J
2011-11-22
There is conflicting information as to whether antiretroviral drugs with better central nervous system (CNS) penetration (neuroHAART) assist in improving neurocognitive function and suppressing cerebrospinal fluid (CSF) HIV RNA. The current review aims to better synthesise existing literature by using an innovative two-phase review approach (qualitative and quantitative) to overcome methodological differences between studies. Sixteen studies, all observational, were identified using a standard citation search. They fulfilled the following inclusion criteria: conducted in the HAART era; sample size > 10; treatment effect involved more than one antiretroviral and none had a retrospective design. The qualitative phase of review of these studies consisted of (i) a blind assessment rating studies on features such as sample size, statistical methods and definitions of neuroHAART, and (ii) a non-blind assessment of the sensitivity of the neuropsychological methods to HIV-associated neurocognitive disorder (HAND). During quantitative evaluation we assessed the statistical power of studies, which achieved a high rating in the qualitative analysis. The objective of the power analysis was to determine the studies ability to assess their proposed research aims. After studies with at least three limitations were excluded in the qualitative phase, six studies remained. All six found a positive effect of neuroHAART on neurocognitive function or CSF HIV suppression. Of these six studies, only two had statistical power of at least 80%. Studies assessed as using more rigorous methods found that neuroHAART was effective in improving neurocognitive function and decreasing CSF viral load, but only two of those studies were adequately statistically powered. Because all of these studies were observational, they represent a less compelling evidence base than randomised control trials for assessing treatment effect. Therefore, large randomised trials are needed to determine the robustness of any neuroHAART effect. However, such trials must be longitudinal, include the full spectrum of HAND, ideally carefully control for co-morbidities, and be based on optimal neuropsychology methods.
Raj, Satish R; Faris, Peter D; Semeniuk, Lisa; Manns, Braden; Krahn, Andrew D; Morillo, Carlos A; Benditt, David G; Sheldon, Robert S
2016-04-01
Vasovagal syncope (VVS) is a common problem associated with a poor quality of life, which improves when syncope frequency is reduced. Effective pharmacological therapies for VVS are lacking. Metoprolol is a β-adrenergic receptor antagonist that is ineffective in younger patients, but may benefit older (≥40 years) VVS patients. Given the limited therapeutic options, a placebo-controlled clinical trial of metoprolol for the prevention of VVS in older patients is needed. The POST5 is a multicenter, international, randomized, placebo-controlled study of metoprolol in the prevention of VVS in patients ≥40 years old. The primary endpoint is the time to first recurrence of syncope. Patients will be randomized 1:1 to receive metoprolol 25 to 100 mg BID or matching placebo, and followed up for 1 year. Secondary end points include syncope frequency, presyncope, quality of life, and cost analysis. Primary analysis will be intention to treat, with a secondary on-treatment analysis. A sample size of 222, split equally between the groups achieves 85% power to detect a hazard rate of 0.3561 when the event rates are 50% and 30% in the placebo and metoprolol arms. Allowing for 10% dropout, we propose to enroll 248 patients. This study will be the first adequately powered trial to determine whether metoprolol is effective in preventing VVS in patients ≥40 years. If effective, metoprolol may become the first line pharmacological therapy for these patients. Copyright © 2016 Elsevier Inc. All rights reserved.
Horn, Austin R; Weijer, Charles; Hey, Spencer Phillips; Brehaut, Jamie; Fergusson, Dean A; Goldstein, Cory E; Grimshaw, Jeremy; Taljaard, Monica
2018-04-27
The ethics of the Flexibility In duty hour Requirements for Surgical Trainees (FIRST) trial have been vehemently debated. Views on the ethics of the FIRST trial range from it being completely unethical to wholly unproblematic. The FIRST trial illustrates the complex ethical challenges posed by cluster randomised trials (CRTs) of policy interventions involving healthcare professionals. In what follows, we have three objectives. First, we critically review the FIRST trial controversy, finding that commentators have failed to sufficiently identify and address many of the relevant ethical issues. The 2012 Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials provides researchers and research ethics committees with specific guidance for the ethical design and conduct of CRTs. Second, we aim to demonstrate how the Ottawa Statement provides much-needed clarity to the ethical issues in the FIRST trial, including: research participant identification; consent requirements; gatekeeper roles; benefit-harm analysis and identification of vulnerable participants. We nonetheless also find that the FIRST trial raises ethical issues not adequately addressed by the Ottawa Statement. Hence, third and finally, we raise important questions requiring further ethical analysis and guidance, including: Does clinical equipoise apply to policy interventions with little or no evidence-base? Do healthcare providers have an obligation to participate in research? Does the power-differential in certain healthcare settings render healthcare providers vulnerable to duress and coercion to participant in research? If so, what safeguards might be implemented to protect providers, while allowing important research to proceed? © 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.
Sachar, Hamita; Pichetshote, Nipaporn; Nandigam, Kavitha; Vaidya, Keta; Laine, Loren
2018-05-01
Current guidelines recommend diphenhydramine in patients undergoing endoscopy who are not adequately sedated with a benzodiazepine and opioid combination. Because this practice has not been adequately assessed, we performed a randomized, double-blind trial comparing diphenhydramine with continued midazolam in such patients. Patients undergoing elective colonoscopy with moderate sedation were eligible. Sedation was measured with the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score with adequate sedation defined as 3 on a 0- to 5-point scale. Patients not adequately sedated with midazolam 5 mg and fentanyl 100 μg were randomly assigned to diphenhydramine 25 mg versus continued midazolam 1.5 mg. Adequacy of sedation was assessed 3 minutes after each study medication dose. If MOAA/S was 4 to 5, study medication was repeated, to a maximum of 3 doses. The primary endpoint was adequate sedation. The planned enrollment of 200 patients (100 in each study group) was attained. Adequate sedation was achieved less often with diphenhydramine than midazolam (27% vs 65%, difference = -38%; 95% CI, -50% to -24%; P < .0001). After study medications were completed, more patients required additional medication for sedation or analgesia with diphenhydramine versus midazolam (84% vs 68%, P = .008), whereas the time to discharge from the recovery unit was similar (134 vs 129 minutes). Treatment effect was consistent across subgroups including age ≤55, substance abuse, benzodiazepine use, opioid use, and psychiatric medication use. Endoscopists performing moderate sedation should continue midazolam rather than switching to diphenhydramine in patients who do not achieve adequate sedation with usual doses of midazolam and an opioid. (Clinical trial registration number: NCT01769586.). Published by Elsevier Inc.
Sarkar, Papri; Mikhail, Emad; Schickler, Robyn; Plosker, Shayne; Imudia, Anthony N
2017-09-01
To estimate the optimal order of office hysteroscopy and endometrial biopsy when performed successively for evaluation of abnormal uterine bleeding. Patients undergoing successive office hysteroscopy and endometrial biopsy were included in a single-blind, prospective, randomized trial. The primary outcome was to evaluate the effect of order of procedures on patients' pain score. Prespecified secondary outcomes include procedure duration, hysteroscopic visualization of the uterine cavity, endometrial sample adequacy, and number of attempts at biopsy. Pain scores were assessed using a visual analog scale from 0 to 10 and endometrial sample adequacy was determined from the histopathology report. Hysteroscopy images were recorded. Sample size of 34 per group (n=68) was determined to be adequate to detect a difference of 20% in visual analog scale score between hysteroscopy first (group A) and biopsy first (group B) at α of 0.05 and 80% power. Between October 2015 and January 2017, 78 women were randomized to group A (n=40) and group B (n=38). There was no difference in global pain perception [7 (0-10) vs 7 (0-10); P=.57, 95% CI 5.8-7.1]. Procedure duration [3 (1-9) vs 3 (2-10), P=.32, 95% CI 3.3-4.1] and endometrial sample adequacy (78.9% vs 75.7%, P=.74) were similar in both groups. Group A patients had better endometrial visualization (P<.001) than group B based on the hysteroscopic images: excellent (50% vs 7.9%), good (20% vs 34.2%), and fair (22.5% vs 44.7%); group B participants required fewer endometrial biopsy attempts at obtaining adequate tissue sample (two vs one; P<.001, 1.6-1.9). Patients having successive office hysteroscopy and endometrial biopsy for evaluation of abnormal uterine bleeding, the global pain perception, and time required are independent of the order in which procedures are performed. Performing hysteroscopy first ensures better image, whereas biopsy first yields adequate tissue sample with fewer attempts. ClinicalTrials.gov, NCT02472184.
Teodoro, P E; Torres, F E; Santos, A D; Corrêa, A M; Nascimento, M; Barroso, L M A; Ceccon, G
2016-05-09
The aim of this study was to evaluate the suitability of statistics as experimental precision degree measures for trials with cowpea (Vigna unguiculata L. Walp.) genotypes. Cowpea genotype yields were evaluated in 29 trials conducted in Brazil between 2005 and 2012. The genotypes were evaluated with a randomized block design with four replications. Ten statistics that were estimated for each trial were compared using descriptive statistics, Pearson correlations, and path analysis. According to the class limits established, selective accuracy and F-test values for genotype, heritability, and the coefficient of determination adequately estimated the degree of experimental precision. Using these statistics, 86.21% of the trials had adequate experimental precision. Selective accuracy and the F-test values for genotype, heritability, and the coefficient of determination were directly related to each other, and were more suitable than the coefficient of variation and the least significant difference (by the Tukey test) to evaluate experimental precision in trials with cowpea genotypes.
Can exergaming contribute to improving physical activity levels and health outcomes in children?
Daley, Amanda J
2009-08-01
Physical inactivity among children is a serious public health problem. It has been suggested that high levels of screen time are contributory factors that encourage sedentary lifestyles in young people. As physical inactivity and obesity levels continue to rise in young people, it has been proposed that new-generation active computer- and video-console games (otherwise known as "exergaming") may offer the opportunity to contribute to young people's energy expenditure during their free time. Although studies have produced some encouraging results regarding the energy costs involved in playing active video-console games, the energy costs of playing the authentic versions of activity-based video games are substantially larger, highlighting that active gaming is no substitute for real sports and activities. A small number of exergaming activities engage children in moderate-intensity activity, but most do not. Only 3 very small trials have considered the effects of exergaming on physical activity levels and/or other health outcomes in children. Evidence from these trials has been mixed; positive trends for improvements in some health outcomes in the intervention groups were noted in 2 trials. No adequately powered randomized, controlled trial has been published to date, and no trial has assessed the long-term impact of exergaming on children's health. We now need high-quality randomized, controlled trials to evaluate the effectiveness and sustainability of exergaming, as well as its clinical relevance; until such studies take place, we should remain cautious about its ability to positively affect children's health.
Eljaiek, Roberto; Heylbroeck, Christophe; Dubois, Marc-Jacques
2017-02-01
The objective was to systematically review the literature summarizing the effect on mortality of albumin compared to non-albumin solutions during the fluid resuscitation phase of burn injured patients. We searched MEDLINE, EMBASE and CENTRAL and the content of two leading journals in burn care, Burns and Journal of Burn Care and Research. Two reviewers independently selected randomized controlled trials comparing albumin vs. non-albumin solutions for the acute resuscitation of patients with >20% body surface area involvement. Reviewers abstracted data independently and assessed methodological quality of the included trials using predefined criteria. A random effects model was used to assess mortality. We identified 164 trials of which, 4 trials involving 140 patients met our inclusion criteria. Overall, the methodological quality of the included trials was fair. We did not find a significant benefit of albumin solutions as resuscitation fluid on mortality in burn patients (relative risk (RR) 1.6; 95% confidence interval (CI), 0.63-4.08). Total volume of fluid infusion during the phase of resuscitation was lower in patients receiving albumin containing solution -1.00ml/kg/%TBSA (total body surface area) (95% CI, -1.42 to -0.58). The pooled estimate demonstrated a neutral effect on mortality in burn patients resuscitated acutely with albumin solutions. Due to limited evidence and uncertainty, an adequately powered, high quality trial could be required to assess the impact of albumin solutions on mortality in burn patients. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.
Lim, Keane; See, Yuen Mei; Lee, Jimmy
2017-11-30
The discovery of endocannabinoid's role within the central nervous system and its potential therapeutic benefits have brought forth rising interest in the use of cannabis for medical purposes. The present review aimed to synthesize and evaluate the available evidences on the efficacy of cannabis and its derivatives for psychiatric, neurodegenerative and movement disorders. A systematic search of randomized controlled trials of cannabis and its derivatives were conducted via databases (PubMed, Embase and the Cochrane Central Register of Controlled Trials). A total of 24 reports that evaluated the use of medical cannabis for Alzheimer's disease, anorexia nervosa, anxiety, dementia, dystonia, Huntington's disease, Parkinson's disease, post-traumatic stress disorder (PTSD), psychosis and Tourette syndrome were included in this review. Trial quality was assessed with the Cochrane risk of bias tool. There is a lack of evidence on the therapeutic effects of cannabinoids for amyotrophic lateral sclerosis and dystonia. Although trials with positive findings were identified for anorexia nervosa, anxiety, PTSD, psychotic symptoms, agitation in Alzheimer's disease and dementia, Huntington's disease, and Tourette syndrome, and dyskinesia in Parkinson's disease, definitive conclusion on its efficacy could not be drawn. Evaluation of these low-quality trials, as rated on the Cochrane risk of bias tools, was challenged by methodological issues such as inadequate description of allocation concealment, blinding and underpowered sample size. More adequately powered controlled trials that examine the long and short term efficacy, safety and tolerability of cannabis for medical use, and the mechanisms underpinning the therapeutic potential are warranted.
Tew, Garry A; Carpenter, Roger; Seed, Michael; Anderson, Simon; Langmead, Louise; Fairhurst, Caroline; Bottoms, Lindsay
2017-01-01
Structured exercise training has been proposed as a useful adjunctive therapy for Crohn's disease by improving immune function and psychological health, reducing fatigue and promoting gains in muscle and bone strength. However, the evidence for exercise in Crohn's disease is sparse, with only a handful of small prospective trials [1, 2], with methodological limitations, including the use of non-randomised and non-controlled study designs and small sample sizes. Here, we describe the protocol for a study that aims to assess the feasibility and acceptability of two common types of exercise training-high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT)-in adults with inactive or mildly active Crohn's disease (CD). This is a randomised, controlled, assessor-blinded, feasibility trial with three parallel groups. Forty-five adults with inactive or mildly active Crohn's disease will be randomly assigned 1:1:1 to HIIT, MICT or usual care control. Participants in the HIIT and MICT groups will be invited to undertake three sessions of supervised exercise each week for 12 consecutive weeks. HIIT sessions will consist of ten 1-min intervals of cycling exercise at 90% of peak power output separated by 1 min of active recovery. MICT sessions will involve 30 min of continuous cycling at 35% of peak power output. Participants will be assessed before randomisation and 13 and 26 weeks after randomisation. Feasibility outcomes include rates of recruitment, retention and adherence. Interviews with participants will explore the acceptability of the exercise programmes and study procedures. Clinical/health outcomes include cardiorespiratory fitness, body mass index, resting blood pressure, markers of disease activity (faecal calprotectin and Crohn's Disease Activity Index) and activated T cell cytokine profiles. Study questionnaires include the Inflammatory Bowel Disease Quality of Life Questionnaire, EQ-5D-5L, IBD Fatigue Scale, Hospital and Anxiety Depression Scale, and International Physical Activity Questionnaire. This study will provide useful information on the feasibility and acceptability of supervised exercise training in adults with inactive and mildly active Crohn's disease and will inform the design of a subsequent, adequately powered, multi-centre trial. The trial is registered with the International Standard Randomised Controlled Trial Register (ISRCTN13021107). Date registration assigned was 02/12/2015.
Are large clinical trials in orthopaedic trauma justified?
Sprague, Sheila; Tornetta, Paul; Slobogean, Gerard P; O'Hara, Nathan N; McKay, Paula; Petrisor, Brad; Jeray, Kyle J; Schemitsch, Emil H; Sanders, David; Bhandari, Mohit
2018-04-20
The objective of this analysis is to evaluate the necessity of large clinical trials using FLOW trial data. The FLOW pilot study and definitive trial were factorial trials evaluating the effect of different irrigation solutions and pressures on re-operation. To explore treatment effects over time, we analyzed data from the pilot and definitive trial in increments of 250 patients until the final sample size of 2447 patients was reached. At each increment we calculated the relative risk (RR) and associated 95% confidence interval (CI) for the treatment effect, and compared the results that would have been reported at the smaller enrolments with those seen in the final, adequately powered study. The pilot study analysis of 89 patients and initial incremental enrolments in the FLOW definitive trial favored low pressure compared to high pressure (RR: 1.50, 95% CI: 0.75-3.04; RR: 1.39, 95% CI: 0.60-3.23, respectively), which is in contradiction to the final enrolment, which found no difference between high and low pressure (RR: 1.04, 95% CI: 0.81-1.33). In the soap versus saline comparison, the FLOW pilot study suggested that re-operation rate was similar in both the soap and saline groups (RR: 0.98, 95% CI: 0.50-1.92), whereas the FLOW definitive trial found that the re-operation rate was higher in the soap treatment arm (RR: 1.28, 95% CI: 1.04-1.57). Our findings suggest that studies with smaller sample sizes would have led to erroneous conclusions in the management of open fracture wounds. NCT01069315 (FLOW Pilot Study) Date of Registration: February 17, 2010, NCT00788398 (FLOW Definitive Trial) Date of Registration: November 10, 2008.
Peyronie's disease intervention trials: methodological challenges and issues.
Müller, Alexander; Mulhall, John P
2009-03-01
Peyronie's Disease (PD) has been studied for more than 260 years since Francois de la Peyronie's description in 1743. Based on the current literature, the prevalence of PD seems 3-9% with an average age of onset in the fifth life decade. Much effort has been spent on developing nonsurgical treatment options to cure or at least prevent disease progression. The recent examination of drug trials for erectile dysfunction has led us to assess PD trial methodology more closely. An Iinternet search on PubMed was performed using MeSH words PD, clinical trials, oral, transdermal, intralesional and shock wave therapy focusing on 26 representing studies published over the last 15 years. Mean Outcome Measures. A comprehensive review of the current literature on nonsurgical treatment options for PD was conducted to address methodological issues and challenges in PD trials highlighting trial design, patient population, and symptom and sign assessment. The majority of the reviewed studies are underpowered and the heterogeneity in the methodological approach and patient assessment between the studies is one of the remarkable findings from our review. Studies should use a uniform means of defining the degree and type of penile deformity and a large enough cohort of patients should be studied for adequate study power. An ideally designed PD intervention trial should comprise: (i) a randomized, placebo-controlled design; (ii) with a PD patient set representative of the general PD population; and (iii) a comprehensive symptom and sign assessment before and at the end of treatment which includes an assessment of at least deformity, pain, and sexual function. A number of challenges exist for the design of PD intervention trials and deciphering the data generated from them. The field would benefit greatly from a consensus statement or guidelines development on the design and conduct of such trials.
Donnelly, Joseph E.; Herrmann, Stephen D.; Lambourne, Kate; Szabo, Amanda N.; Honas, Jeffery J.; Washburn, Richard A.
2014-01-01
Background The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. Objective To address the question: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? Data Sources PubMed and Embase were searched (January 1990–January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Study Eligibility Criteria Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18–64 years). Study Appraisal and Synthesis Methods Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. Results No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. Limitations The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. Conclusions We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake. PMID:24454704
Han, Changsu; Wang, Sheng-Min; Lee, Soo-Jung; Jun, Tae-Youn
2015-01-01
Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD. PMID:26306301
[Patient's individuality and application of guidelines in surgery].
Schulte, Michael
2005-01-01
Individual treatment decisions can become considerably conflictual in view of the co-existence of medical professional guidelines, recommendations based on evidence-based medicine (EBM), and juridical and economical directions. Medical guidelines are not subject to an external review process; also, due to reduced practicability, the surgeons' compliance with guidelines remains relatively low. Surgical treatment strategies can rely on randomized clinical trials (RCTs) in approximately 20% of the surgical procedures and on non-randomized trials in approximately 70% of the cases. No evidence is given in approximately 10% of the cases. Specific problems of implementation of EBM in surgical disciplines are represented by the difficulty of standardized procedures, the heterogeneity of the population, the impossibility to conduct double-blinded RCTs, a low statistical power, and a publication bias. Since individual diseases cannot be reduced to surgical cases manageable only by the application of guidelines, adequate treatment of individual patients requires the critical application of both external evidence and surgeon expertise (internal evidence).
Placebo non-response measure in sequential parallel comparison design studies.
Rybin, Denis; Doros, Gheorghe; Pencina, Michael J; Fava, Maurizio
2015-07-10
The Sequential Parallel Comparison Design (SPCD) is one of the novel approaches addressing placebo response. The analysis of SPCD data typically classifies subjects as 'placebo responders' or 'placebo non-responders'. Most current methods employed for analysis of SPCD data utilize only a part of the data collected during the trial. A repeated measures model was proposed for analysis of continuous outcomes that permitted the inclusion of information from all subjects into the treatment effect estimation. We describe here a new approach using a weighted repeated measures model that further improves the utilization of data collected during the trial, allowing the incorporation of information that is relevant to the placebo response, and dealing with the problem of possible misclassification of subjects. Our simulations show that when compared to the unweighted repeated measures model method, our approach performs as well or, under certain conditions, better, in preserving the type I error, achieving adequate power and minimizing the mean squared error. Copyright © 2015 John Wiley & Sons, Ltd.
Windows of Opportunity for Lifestyle Interventions to Prevent Gestational Diabetes Mellitus
Phelan, Suzanne
2017-01-01
Gestational diabetes mellitus (GDM) is linked with several acute maternal health risks and long-term development of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM similarly increases offspring risk of early life health complications and later disease. GDM recurrence is common, affecting 40–73% of women, and augments associated maternal/fetal/child health risks. Modifiable and independent risk factors for GDM include maternal excessive gestational weight gain and pre-pregnancy overweight and obesity. Lifestyle interventions that target diet, activity, and behavioral strategies can effectively modify adiposity. Randomized clinical trials testing the effects of lifestyle interventions during pregnancy to reduce excessive gestational weight gain have generally shown mixed effects on reducing GDM incidence. Trials testing the effects of postpartum lifestyle interventions among women with a history of GDM have shown reduced incidence of diabetes and improved cardiovascular disease risk factors. However, the long-term effects of inter-pregnancy or pre-pregnancy lifestyle interventions on subsequent GDM remain unknown. Future adequately powered and well-controlled clinical trials are needed to determine the effects of lifestyle interventions to prevent GDM and identify pathways to effectively reach reproductive-aged women across all levels of society, before, during, and after pregnancy. PMID:27487229
Antioxidants and cancer therapy: a systematic review.
Ladas, Elena J; Jacobson, Judith S; Kennedy, Deborah D; Teel, Katherine; Fleischauer, Aaron; Kelly, Kara M
2004-02-01
Many patients with cancer take antioxidant nutritional supplements during cancer treatment to alleviate treatment toxicities and to improve long-term outcomes, but little is known about the efficacy and safety of antioxidant use during cancer treatment. We reviewed English-language manuscripts published in the biomedical literature, reporting the results of observational studies of antioxidant status and cancer outcomes and of intervention trials of antioxidants among patients receiving chemotherapy with or without radiation for various malignancies. We searched the Medline database and the bibliographies of the retrieved manuscripts, reviews, and books on antioxidants and cancer. The retrieved studies are grouped by study design, malignancy, and end points. More than 100 citations were retrieved; 52 met our criteria, 31 were observational studies, and 21 were intervention trials. The studies varied in study design, timing of observation/intervention, intervention protocol, malignancy, and anticancer regimen. These inconsistencies preclude a definitive conclusion as to the effect of chemotherapy on antioxidant status in patients undergoing anticancer therapy. However, our review suggests that total antioxidant status (measured by total radical antioxidant parameter) declines during cancer treatment. Adequately powered trials or observational studies among patients with a specific cancer diagnosis receiving a specific treatment regimen are needed to address patients' and physicians' concerns regarding these associations.
Free, Caroline; Phillips, Gemma; Galli, Leandro; Watson, Louise; Felix, Lambert; Edwards, Phil; Patel, Vikram; Haines, Andy
2013-01-01
Background Mobile technologies could be a powerful media for providing individual level support to health care consumers. We conducted a systematic review to assess the effectiveness of mobile technology interventions delivered to health care consumers. Methods and Findings We searched for all controlled trials of mobile technology-based health interventions delivered to health care consumers using MEDLINE, EMBASE, PsycINFO, Global Health, Web of Science, Cochrane Library, UK NHS HTA (Jan 1990–Sept 2010). Two authors extracted data on allocation concealment, allocation sequence, blinding, completeness of follow-up, and measures of effect. We calculated effect estimates and used random effects meta-analysis. We identified 75 trials. Fifty-nine trials investigated the use of mobile technologies to improve disease management and 26 trials investigated their use to change health behaviours. Nearly all trials were conducted in high-income countries. Four trials had a low risk of bias. Two trials of disease management had low risk of bias; in one, antiretroviral (ART) adherence, use of text messages reduced high viral load (>400 copies), with a relative risk (RR) of 0.85 (95% CI 0.72–0.99), but no statistically significant benefit on mortality (RR 0.79 [95% CI 0.47–1.32]). In a second, a PDA based intervention increased scores for perceived self care agency in lung transplant patients. Two trials of health behaviour management had low risk of bias. The pooled effect of text messaging smoking cessation support on biochemically verified smoking cessation was (RR 2.16 [95% CI 1.77–2.62]). Interventions for other conditions showed suggestive benefits in some cases, but the results were not consistent. No evidence of publication bias was demonstrated on visual or statistical examination of the funnel plots for either disease management or health behaviours. To address the limitation of the older search, we also reviewed more recent literature. Conclusions Text messaging interventions increased adherence to ART and smoking cessation and should be considered for inclusion in services. Although there is suggestive evidence of benefit in some other areas, high quality adequately powered trials of optimised interventions are required to evaluate effects on objective outcomes. Please see later in the article for the Editors' Summary PMID:23349621
Liposomal bupivacaine for regional anesthesia.
Uskova, Anna; O'Connor, Jessica E
2015-10-01
Using a regional block in a multimodal approach to postoperative analgesia management involves addressing, which local anesthetic and how much should be used to ensure adequate pain relief to reduce related morbidity and mortality. This article will review literature surrounding the recently approved formulation of slow release liposomal bupivacaine, define its proven benefits, and identify ongoing studies to further examine the utility of this novel formulation by various routes. Recent Phase II and III clinical trials have demonstrated the ability of liposomal bupivacaine to provide prolonged analgesia, maintain a high safety profile in therapeutic doses, and decrease opioid requirements when compared with placebo in local infiltration applications for up to 24 h. Between 24 and 72 h after study drug administration, there was minimal to no difference between EXPAREL and placebo treatments on mean pain intensity. Conventional bupivacaine or ropivacaine groups (current standard practice in many hospitals in the USA) were not compared. In addition, the analgesic efficacy, cost-effectiveness, and safety profile of liposomal bupivacaine has not thoroughly been studied in various standard clinical settings such as perineural, intrathecal, and epidural administration. Current published data do not provide superior clinical results for EXPAREL over conventional bupivacaine based upon the lack of adequately powered multicentered clinical trials with comparison groups. Further investigation is necessary to identify the analgesic efficacy and safety profile of liposomal bupivacaine versus standard local anesthetics and to define the optimal clinical indication for liposomal bupivacaine administration in regional anesthesia.
Keefe, Richard S. E.; Buchanan, Robert W.; Marder, Stephen R.; Schooler, Nina R.; Dugar, Ashish; Zivkov, Milana; Stewart, Michelle
2013-01-01
In light of the number of studies conducted to examine the treatment of cognitive impairment associated with schizophrenia (CIAS), we critically reviewed recent CIAS trials. Trials were identified through searches of the website “www.clinicaltrials.gov” using the terms “schizophrenia AND cognition,” “schizophrenia AND neurocognition,” “schizophrenia AND neurocognitive tests,” “schizophrenia AND MATRICS,” “schizophrenia AND MCCB,” “schizophrenia AND BACS,” “schizophrenia AND COGSTATE,” and “schizophrenia AND CANTAB” and “first-episode schizophrenia AND cognition.” The cutoff date was 20 April 2011. Included trials were conducted in people with schizophrenia, the effects on cognition were either a primary or secondary outcome, and the effect of a pharmacologically active substance was examined. Drug challenge, pharmacokinetic, pharmacodynamic, or prodrome of psychosis studies were excluded. We identified 118 trials, with 62% using an add-on parallel group design. The large majority of completed trials were underpowered to detect moderate effect sizes, had ≤8 weeks duration, and were performed in samples of participants with chronic stable schizophrenia. The ongoing add-on trials are longer, have larger sample sizes (with a number of them being adequately powered to detect moderate effect sizes), and are more likely to use a widely accepted standardized cognitive battery (eg, the MATRICS Consensus Cognitive Battery) and MATRICS guidelines. Ongoing studies performed in subjects with recent onset schizophrenia may help elucidate which subjects are most likely to show an effect in cognition. New insights into the demands of CIAS trial design and methodology may help increase the probability of identifying treatments with beneficial effect on cognitive impairment in schizophrenia. PMID:22114098
Accuracy of the Velotron ergometer and SRM power meter.
Abbiss, C R; Quod, M J; Levin, G; Martin, D T; Laursen, P B
2009-02-01
The purpose of this study was to determine the accuracy of the Velotron cycle ergometer and the SRM power meter using a dynamic calibration rig over a range of exercise protocols commonly applied in laboratory settings. These trials included two sustained constant power trials (250 W and 414 W), two incremental power trials and three high-intensity interval power trials. To further compare the two systems, 15 subjects performed three dynamic 30 km performance time trials. The Velotron and SRM displayed accurate measurements of power during both constant power trials (<1% error). However, during high-intensity interval trials the Velotron and SRM were found to be less accurate (3.0%, CI=1.6-4.5% and -2.6%, CI=-3.2--2.0% error, respectively). During the dynamic 30 km time trials, power measured by the Velotron was 3.7+/-1.9% (CI=2.9-4.8%) greater than that measured by the SRM. In conclusion, the accuracy of the Velotron cycle ergometer and the SRM power meter appears to be dependent on the type of test being performed. Furthermore, as each power monitoring system measures power at various positions (i.e. bottom bracket vs. rear wheel), caution should be taken when comparing power across the two systems, particularly when power is variable.
Donnelly, J E; Ptomey, L T; Goetz, J R; Sullivan, D K; Gibson, C A; Greene, J L; Lee, R H; Mayo, M S; Honas, J J; Washburn, R A
2016-11-01
Adolescents with intellectual and developmental disabilities (IDD) are an underserved group in need of weight management. However, information regarding effective weight management for this group is limited, and is based primarily on results from small, non-powered, non-randomized trials that were not conducted in accordance with current weight management guidelines. Additionally, the comparative effectiveness of emerging dietary approaches, such as portion-controlled meals (PCMs) or program delivery strategies such as video chat using tablet computers have not been evaluated. Therefore, we will conduct an 18month trial to compare weight loss (6months) and maintenance (7-18months) in 123 overweight/obese adolescents with mild to moderate IDD, and a parent, randomized to a weight management intervention delivered remotely using FaceTime™ on an iPad using either a conventional meal plan diet (RD/CD) or a Stop Light diet enhanced with PCMs (RD/eSLD), or conventional diet delivered during face-to-face home visits (FTF/CD). This design will provide an adequately powered comparison of both diet (CD vs. eSLD) and delivery strategy (FTF vs. RD). Exploratory analyses will examine the influence of behavioral session attendance, compliance with recommendations for diet (energy intake), physical activity (min/day), self-monitoring of diet and physical activity, medications, and parental variables including diet quality, physical activity, baseline weight, weight change, and beliefs and attitudes regarding diet and physical activity on both weight loss and maintenance. We will also complete a cost and contingent valuation analysis to compare costs between RD and FTF delivery. Copyright © 2016. Published by Elsevier Inc.
Ekeland, E; Heian, F; Hagen, K; Coren, E
2005-01-01
Twenty three randomised controlled trials were analysed. A synthesis of several small, low quality trials indicates that exercise may have short term beneficial effects on self esteem in children and adolescents. However, high quality research on defined populations with adequate follow up is needed. PMID:16244186
Grimes, Jack E. T.; Croll, David; Harrison, Wendy E.; Utzinger, Jürg; Freeman, Matthew C.; Templeton, Michael R.
2014-01-01
Background Access to “safe” water and “adequate” sanitation are emphasized as important measures for schistosomiasis control. Indeed, the schistosomes' lifecycles suggest that their transmission may be reduced through safe water and adequate sanitation. However, the evidence has not previously been compiled in a systematic review. Methodology We carried out a systematic review and meta-analysis of studies reporting schistosome infection rates in people who do or do not have access to safe water and adequate sanitation. PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to 31 December 2013, without restrictions on year of publication or language. Studies' titles and abstracts were screened by two independent assessors. Papers deemed of interest were read in full and appropriate studies included in the meta-analysis. Publication bias was assessed through the visual inspection of funnel plots and through Egger's test. Heterogeneity of datasets within the meta-analysis was quantified using Higgins' I2. Principal Findings Safe water supplies were associated with significantly lower odds of schistosomiasis (odds ratio (OR) = 0.53, 95% confidence interval (CI): 0.47–0.61). Adequate sanitation was associated with lower odds of Schistosoma mansoni, (OR = 0.59, 95% CI: 0.47–0.73) and Schistosoma haematobium (OR = 0.69, 95% CI: 0.57–0.84). Included studies were mainly cross-sectional and quality was largely poor. Conclusions/Significance Our systematic review and meta-analysis suggests that increasing access to safe water and adequate sanitation are important measures to reduce the odds of schistosome infection. However, most of the studies were observational and quality was poor. Hence, there is a pressing need for adequately powered cluster randomized trials comparing schistosome infection risk with access to safe water and adequate sanitation, more studies which rigorously define water and sanitation, and new research on the relationships between water, sanitation, hygiene, human behavior, and schistosome transmission. PMID:25474705
Uric acid and progression of chronic kidney disease.
Weaver, Donald J
2018-06-21
The association between serum uric acid levels and human disease has garnered intense interest over the last decade including chronic kidney disease. Animal studies have provided evidence for a potential mechanistic role of uric acid in promoting progression of chronic kidney disease. Epidemiologic studies have also suggested an association between elevated serum uric acid levels and worsening renal function in the general population as well as in patients with chronic kidney disease. However, there is currently insufficient evidence to recommend the use of uric acid-lowering therapy to delay progression of chronic kidney disease in this patient population. Adequately powered, randomized, placebo-controlled trials are required to more precisely evaluate the risk and benefits of uric acid-lowering therapy in pediatric patients.
Duvvuri, Vikas; Cromley, Taya; Klabunde, Megan; Boutelle, Kerri; Kaye, Walter H
2012-03-01
No studies have compared the response to selective serotonin reuptake inhibitors and atypical antipsychotics in anorexia nervosa. This case study examines such a comparison. This report describes a case of 12-year-old identical twins with anorexia nervosa, one of whom was treated with olanzapine and the other with fluoxetine, while undergoing family therapy. Twin A treated with fluoxetine went from 75 to 84.4% ideal body weight, while Twin B treated with olanzapine went from 72 to 99.9% ideal body weight over the course of 9 months. This case supports the need for adequately powered, controlled clinical trials to test the efficacy of olanzapine in adolescents presenting with anorexia nervosa. Copyright © 2011 Wiley Periodicals, Inc.
Steffens, Daniel; Hancock, Mark J; Pereira, Leani S M; Kent, Peter M; Latimer, Jane; Maher, Chris G
2016-04-01
Magnetic resonance imaging (MRI) can reveal a range of degenerative findings and anatomical abnormalities; however, the clinical importance of these remains uncertain and controversial. We aimed to investigate if the presence of MRI findings identifies patients with low back pain (LBP) or sciatica who respond better to particular interventions. MEDLINE, EMBASE and CENTRAL databases were searched. We included RCTs investigating MRI findings as treatment effect modifiers for patients with LBP or sciatica. We excluded studies with specific diseases as the cause of LBP. Risk of bias was assessed using the criteria of the Cochrane Back Review Group. Each MRI finding was examined for its individual capacity for effect modification. Eight published trials met the inclusion criteria. The methodological quality of trials was inconsistent. Substantial variability in MRI findings, treatments and outcomes across the eight trials prevented pooling of data. Patients with Modic type 1 when compared with patients with Modic type 2 had greater improvements in function when treated by Diprospan (steroid) injection, compared with saline. Patients with central disc herniation when compared with patients without central disc herniation had greater improvements in pain when treated by surgery, compared with rehabilitation. Although individual trials suggested that some MRI findings might be effect modifiers for specific interventions, none of these interactions were investigated in more than a single trial. High quality, adequately powered trials investigating MRI findings as effect modifiers are essential to determine the clinical importance of MRI findings in LBP and sciatica ( CRD42013006571).
Lowe, Catherine J Minns; Davies, Linda; Sackley, Catherine M; Barker, Karen L
2015-09-01
Existing review required updating. To evaluate the effectiveness of physiotherapy exercise after discharge from hospital on function, walking, range of motion, quality of life and muscle strength, for patients following elective primary total hip arthroplasty for osteoarthritis. Systematic review from January 2007 to November 2013. AMED, CINAHL, EMBASE, MEDLINE, Kingsfund Database, and PEDro. Cochrane CENTRAL, BioMed Central (BMC), The Department of Health National Research Register and Clinical Trials.gov register. Searches were overseen by a librarian. Authors were contacted for missing information. No language restrictions were applied. Trials comparing physiotherapy exercise vs usual/standard care, or comparing two types of relevant exercise physiotherapy, following discharge from hospital after elective primary total hip replacement for osteoarthritis were reviewed. Functional activities of daily living, walking, quality of life, muscle strength and joint range of motion. Quality and risk of bias for studies were evaluated. Data were extracted and meta-analyses considered. 11 trials are included in the review. Trial quality was mixed. Newly included studies were assessed as having lower risk of bias than previous studies. Narrative review indicates that physiotherapy exercise after discharge following total hip replacement may potentially benefit patients in terms of function, walking and muscle strengthening. The overall quality and quantity of trials, and their diversity, prevented meta-analyses. Disappointingly, insufficient evidence still prevents the effectiveness of physiotherapy exercise following discharge to be determined for this patient group. High quality, adequately powered, trials with long term follow up are required. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
Aspirin for in vitro fertilisation.
Siristatidis, Charalambos S; Dodd, Susanna R; Drakeley, Andrew J
2011-08-10
Aspirin is used to improve the outcome in women undergoing in vitro fertilisation despite inconsistent evidence of its efficacy. The most appropriate time to commence aspirin therapy and the length of treatment required are also still to be determined. This is an update of the review first published in 2007. To determine the effectiveness and safety of aspirin for improving the outcome of in vitro fertilisation and intracytoplasmic sperm injection treatment cycles. We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library January 2011), MEDLINE (1966 to January 2011) and EMBASE (1980 to January 2011) databases. We used the research terms: "(aspirin OR acetylsalicylic acid) AND (in-vitro fertilisation OR intracytoplasmic sperm injection)", combined with the Cochrane Menstrual Disorders and Subfertility Group's search strategy, in order to identify randomised controlled trials on aspirin for women undergoing in vitro fertilisation. Randomised controlled trials. Two authors independently selected studies to include in the review, extracted data and assessed trial quality. The searches identified 13 trials which were eligible for inclusion in the review, including a total of 2653 participants. No significant differences were found between the treatment and control groups for any of the outcomes assessed. No significant differences were found in the meta-analysis of studies investigating the effect of aspirin compared with control on live birth rate (RR 0.91, 95% CI 0.72 to 1.15; three studies and 1053 participants), clinical pregnancy rate (RR 1.03, 95% CI 0.91 to 1.17; 10 studies and 2142 participants), ectopic and miscarriage rates (RR 1.86, 95% CI 0.75 to 4.63; RR 1.10, 95% CI 0.68 to 1.77) respectively (three and five studies involving 1135 and 1497 participants). Use of aspirin for women undergoing in vitro fertilisation cannot be recommended due to lack of evidence from the current trial data. Adequately powered trials are needed. It was proposed in the initial version of this review that a sample size of 350 women in each group would be required in order to demonstrate a 10% improvement from the use of aspirin, with 80% power at the 5% significance level. Until such evidence is available, this treatment can not be recommended.
Petricevic, Mate; Kopjar, Tomislav; Gasparovic, Hrvoje; Milicic, Davor; Svetina, Lucija; Zdilar, Boris; Boban, Marko; Mihaljevic, Martina Zrno; Biocina, Bojan
2015-05-01
Individual variability in the response to aspirin, has been established by various platelet function assays, however, the clinical relevance of aspirin resistance (AR) in patients undergoing coronary artery bypass grafting (CABG) has to be evaluated. Our working group conducted a randomized controlled trial (NCT01159639) with the aim to assess impact of dual antiplatelet therapy (APT) on outcomes among patients with AR following CABG. Patients that were aspirin resistant on fourth postoperative day (POD 4) were randomly assigned to receive either dual APT with clopidogrel (75 mg) plus aspirin (300 mg)-intervention arm or monotherapy with aspirin (300 mg)-control arm. This exploratory analysis compares clinical outcomes between aspirin resistant patients allocated to control arm and patients that have had adequate platelet inhibitory response to aspirin at POD 4. Both groups were treated with 300 mg of aspirin per day following surgery. We sought to evaluate the impact of early postoperative AR on outcomes among patients following CABG. Exploratory analysis included a total number of 325 patients. Of those, 215 patients with adequate response to aspirin and 110 patients with AR allocated to aspirin monotherapy following randomization protocol. The primary efficacy end point (MACCEs-major adverse cardiac and cardiovascular events) occurred in 10 and 6 % of patients with AR and with adequate aspirin response, respectively (p = 0.27). Non-significant differences were observed in bleeding events occurrence. Subgroup analysis of the primary end point revealed that aspirin resistant patients with BMI > 30 kg/m(2) tend to have a higher occurrence of MACCEs 18 versus 5 % (relative risk 0.44 [95 % CI 0.16-1.16]; p = 0.05). This exploratory analysis did not reveal significant impact of aspirin resistance on outcomes among patients undergoing CABG. Further, sufficiently powered studies are needed in order to evaluate clinical relevance of AR in patients undergoing CABG.
East, Christine E; Kane, Stefan C; Davey, Mary-Ann; Kamlin, C Omar; Brennecke, Shaun P
2015-11-03
The rate of caesarean sections around the world is rising each year, reaching epidemic proportions. Although many caesarean sections are performed for concerns about fetal welfare on the basis of abnormal cardiotocography, the majority of babies are shown to be well at birth, meaning that the operation, with its inherent short and long term risks, could have been avoided without compromising the baby's health. Previously, fetal scalp blood sampling for pH estimation was performed in the context of an abnormal cardiotocograph, to improve the identification of babies in need of expedited delivery. This test has largely been replaced by lactate measurement, although its validity is yet to be established through a randomised controlled trial. This study aims to test the hypothesis that the performance of fetal scalp blood lactate measurement for women in labour with an abnormal cardiotocograph will reduce the rate of birth by caesarean section from 38 % to 25 % (a 35 % relative reduction). Prospective unblinded randomised controlled trial conducted at a single tertiary perinatal centre. Women labouring with a singleton fetus in cephalic presentation at 37 or more weeks' gestation with ruptured membranes and with an abnormal cardiotocograph will be eligible. Participants will be randomised to one of two groups: fetal monitoring by cardiotocography alone, or cardiotocography augmented by fetal scalp blood lactate analysis. Decisions regarding the timing and mode of delivery will be made by the treating team, in accordance with hospital protocols. The primary study endpoint is caesarean section with secondary outcomes collected from maternal, fetal and neonatal clinical course and morbidities. A cost effectiveness analysis will also be performed. A sample size of 600 will provide 90 % power to detect the hypothesised difference in the proportion of women who give birth by caesarean section. This world-first trial is adequately powered to determine the impact of fetal scalp blood lactate measurement on rates of caesarean section. Preventing unnecessary caesarean sections will reduce the health and financial burdens associated with this operation, both in the index and any future pregnancies. Australian New Zealand Clinical Trials Registry ACTRN12611000172909.
2013-01-01
Background People with dementia have a disproportionately high rate of falls and fractures and poorer outcomes, yet there is currently no evidence to guide falls prevention in this population. Methods A randomised trial design was used to test feasibility of study components and acceptability of a home hazard reduction and balance and strength exercise fall prevention program. The program was tailored to participant’s individual cognitive levels and implemented as a carer-supported intervention. Feasibility of recruitment, retention and implementation of intervention were recorded through observation and documented in field notes. Adherence, carer burden and use of task simplification strategies were also monitored. Outcome measures, collected at 12 weeks included physiological, fear of falling, cognitive and functional measures. Results Recruitment was achievable but may be more challenging in a multisite trial. Twenty two dyads of persons with mild dementia and their carers were randomised to intervention or usual care control group. Of 38 dyads referred to the study, there was a high rate of willingness to participate, with 6 (16%) declining and 10 (26%) not meeting inclusion criteria. The intervention was well received by participants and carers and adherence to both program components was very good. All participants implemented some home safety recommendations (range 19-80%) with half implementing 50% or more. At the end of 12 weeks, 72% of the intervention group were exercising. Both the rate of falling and the risk of a fall were lower in the intervention group but these findings were not significant (RR= 0.50 (95% CI 0.11-2.19). There were no differences in physiological outcome measures between the control and intervention groups. However results were influenced by the small study size and incomplete data primarily in the intervention group at follow up. Conclusions The pilot study was feasible and acceptable to people with mild dementia and their carers. The lessons learnt included: recruitment for a larger trial will require multiple approaches; home safety recommendations should provide a greater emphasis on environmental use compared with behavioural change; strategies to ensure an adequate dosage of exercise should be further explored. We recommend that intervention delivery incorporate an integrated occupational therapy and physiotherapy approach and that carers be provided with an individualised session to enhance dementia-specific skills in management and communication. A refined intervention should be tested in a randomised trial with an adequately powered sample size. Trial registration Australia and New Zealand Clinical Trials Registry 126100001049066 PMID:24004682
Pacing Strategy in Short Cycling Time Trials.
de Jong, Jelle; van der Meijden, Linda; Hamby, Simone; Suckow, Samantha; Dodge, Christopher; de Koning, Jos J; Foster, Carl
2015-11-01
To reach top performance in cycling, optimizing distribution of energy resources is crucial. The purpose of this study was to investigate power output during 250-m, 500-m, and 1000-m cycling time trials and the characteristics of the adopted pacing strategy. Nine trained cyclists completed an incremental test and 3 time trials that they were instructed to finish as quickly as possible. Preceding the trials, peak power during short sprints (PP sprint) and gross efficiency (GE) were measured. During the trials, power output and oxygen consumption were measured to calculate the contribution of the aerobic and anaerobic energy sources. After the trial GE was measured again. Peak power during all trials (PPTT) was lower than PP sprint. In the 250-m trial the PPTT was higher in the 1000-m trial (P = .008). The subjects performed a significantly longer time at high intensity in the 250-m than in the 1000-m (P = .029). GE declined significantly during all trials (P < .01). Total anaerobically attributable work was less in the 250-m than in the 500-m (P = .015) and 1000-m (P < .01) trials. The overall pacing pattern in the 250-m trial appears to follow an all-out strategy, although peak power is still lower than the potential maximal power output. This suggests that a true all-out pattern of power output may not be used in fixed-distance events. The 500-m and 1000-m had a more conservative pacing pattern and anaerobic power output reached a constant magnitude.
Adjusting for multiple prognostic factors in the analysis of randomised trials
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
van Gaal, Betsie GI; Knoll, Jacqueline L; Cornelissen, Elisabeth AM; Schoonhoven, Lisette; Kok, Gerjo
2016-01-01
Background The care for children with a chronic kidney disease (CKD) is complex. Parents of these children may experience high levels of stress in managing their child’s disease, potentially leading to negative effects on their child’s health outcomes. Although the experienced problems are well known, adequate (online) support for these parents is lacking. Objective The objective of the study is to describe the systematic development of an online support program for parents of children with CKD, and how this program will be evaluated. Methods Intervention Mapping (IM) was used for the development of the program. After conducting a needs assessment, defining program objectives, searching for theories, and selecting practical applications, the online program e-Powered Parents was developed. e-Powered Parents consist of three parts: (1) an informative part with information about CKD and treatments, (2) an interactive part where parents can communicate with other parents and health care professionals by chat, private messages, and a forum, and (3) a training platform consisting of four modules: Managing stress, Setting limits, Communication, and Coping with emotions. In a feasibility study, the potential effectiveness and effect size of e-Powered Parents will be evaluated using an explorative randomized controlled trial with parents of 120 families. The outcomes will be the child’s quality of life, parental stress and fatigue, self-efficacy in the communication with health care professionals, and family management. A process evaluation will provide insight in parents’ experiences, including their experienced level of support. Results Study results are expected to be published in the summer of 2016. Conclusions Although the development of e-Powered Parents using IM was time-consuming, IM has been a useful protocol. IM provided us with a systematic framework for structuring the development process. The participatory planning group was valuable as well; knowledge, experiences, and visions were shared, ensuring us that parents and health care professionals support the program. Trial Registration Dutch Trial Registration: NTR4808; www.trialregister.nl (Archived by WebCite at http://www.webcitation.org/6cfAYHcYb) PMID:26764218
Rada, Gabriel; Schünemann, Holger J; Labedi, Nawman; El-Hachem, Pierre; Kairouz, Victor F; Akl, Elie A
2013-02-14
Randomized controlled trials (RCTs) that are inappropriately designed or executed may provide biased findings and mislead clinical practice. In view of recent interest in the treatment and prevention of thrombotic complications in cancer patients we evaluated the characteristics, risk of bias and their time trends in RCTs of anticoagulation in patients with cancer. We conducted a comprehensive search, including a search of four electronic databases (MEDLINE, EMBASE, ISI the Web of Science, and CENTRAL) up to February 2010. We included RCTs in which the intervention and/or comparison consisted of: vitamin K antagonists, unfractionated heparin (UFH), low molecular weight heparin (LMWH), direct thrombin inhibitors or fondaparinux. We performed descriptive analyses and assessed the association between the variables of interest and the year of publication. We included 67 RCTs with 24,071 participants. In twenty one trials (31%) DVT diagnosis was triggered by clinical suspicion; the remaining trials either screened for DVT or were unclear about their approach. 41 (61%), 22 (33%), and 11 (16%) trials respectively reported on major bleeding, minor bleeding, and thrombocytopenia. The percentages of trials satisfying risk of bias criteria were: adequate sequence generation (85%), adequate allocation concealment (61%), participants' blinding (39%), data collectors' blinding (44%), providers' blinding (41%), outcome assessors' blinding (75%), data analysts' blinding (15%), intention to treat analysis (57%), no selective outcome reporting (12%), no stopping early for benefit (97%). The mean follow-up rate was 96%. Adequate allocation concealment and the reporting of intention to treat analysis were the only two quality criteria that improved over time. Many RCTs of anticoagulation in patients with cancer appear to use insufficiently rigorous outcome assessment methods and to have deficiencies in key methodological features. It is not clear whether this reflects a problem in the design, conduct or the reporting of these trials, or both. Future trials should avoid the shortcomings described in this article.
Artemisinin derivatives for treating severe malaria.
McIntosh, H M; Olliaro, P
2000-01-01
Artemisinin derivatives may have advantages over quinoline drugs for treating severe malaria since they are fast acting and effective against quinine resistant malaria parasites. The objective of this review was to assess the effects of artemisinin drugs for severe and complicated falciparum malaria in adults and children. We searched the Cochrane Infectious Diseases Group trials register, Cochrane Controlled Trials Register, Medline, Embase, Science Citation Index, Lilacs, African Index Medicus, conference abstracts and reference lists of articles. We contacted organisations, researchers in the field and drug companies. Randomised and pseudo-randomised trials comparing artemisinin drugs (rectal, intramuscular or intravenous) with standard treatment, or comparisons between artemisinin derivatives in adults or children with severe or complicated falciparum malaria. Eligibility, trial quality assessment and data extraction were done independently by two reviewers. Study authors were contacted for additional information. Twenty three trials are included, allocation concealment was adequate in nine. Sixteen trials compared artemisinin drugs with quinine in 2653 patients. Artemisinin drugs were associated with better survival (mortality odds ratio 0.61, 95% confidence interval 0.46 to 0.82, random effects model). In trials where concealment of allocation was adequate (2261 patients), this was barely statistically significant (odds ratio 0.72, 95% CI 0.54 to 0.96, random effects model). In 1939 patients with cerebral malaria, mortality was also lower with artemisinin drugs overall (odds ratio 0.63, 95% CI 0.44 to 0.88, random effects model). The difference was not significant however when only trials reporting adequate concealment of allocation were analysed (odds ratio 0.78, 95% CI 0.55 to 1.10, random effects model) based on 1607 patients. No difference in neurological sequelae was shown. Compared with quinine, artemisinin drugs showed faster parasite clearance from the blood and similar adverse effects. The evidence suggests that artemisinin drugs are no worse than quinine in preventing death in severe or complicated malaria. No artemisinin derivative appears to be better than the others.
Effects of AED device features on performance by untrained laypersons.
Mosesso, Vincent N; Shapiro, Alan H; Stein, Karen; Burkett, Kelly; Wang, Henry
2009-11-01
Our study evaluates the impact of features of automated external defibrillators (AEDs) on the performance and speed of untrained laypersons to deliver a shock and initiate CPR after a shock. This was a randomized trial of volunteer laypersons without AED or advanced medical training. Subjects were assigned to use one of six different models of AEDs on a manikin in simulated cardiac arrest. No instructions on AED operation were provided. Primary endpoints were shock delivery and elapsed time from start to shock. Secondary endpoints included time to power-on, initiation of CPR, adequacy of pad placement and subjects' ratings of ease of use (1=very easy, 5=very difficult). Most subjects (109/120; 91%) were able to deliver a shock. Median time from start of scenario to shock delivery was 79 s (IQR: 67-99). Of the 11 participants who did not deliver shock, eight never powered on the device. Time to power-on was shorter in devices with open lid (median 12s, IQR 8-27 s) and pull handle (17s, IQR 9-20s) mechanisms than with a push button (37s, IQR 18-69 s; p=0.000). Pad position on the manikin was judged adequate for 86 (77%) of the 111 subjects who placed pads. Devices which gave more detailed voice instruction for pad placement had higher rates of adequate pad position [38/39 (97%) versus 50/73 (68%), p=0.001]. With AEDs that provided step-by-step CPR instruction, 49/58 (84%) subjects began CPR compared to 26/51 (51%) with AEDs that only prompted to start CPR (p=0.01). Participants rated all the models easy to use (overall mean 1.48; individual device means 1.28-1.71). Most untrained laypersons were successful in delivering a shock. Device features had the most impact on these functions: ability and time to power-on device, adequacy of pad position and initiation of CPR.
Acute Respiratory Distress Syndrome Measurement Error. Potential Effect on Clinical Study Results
Cooke, Colin R.; Iwashyna, Theodore J.; Hofer, Timothy P.
2016-01-01
Rationale: Identifying patients with acute respiratory distress syndrome (ARDS) is a recognized challenge. Experts often have only moderate agreement when applying the clinical definition of ARDS to patients. However, no study has fully examined the implications of low reliability measurement of ARDS on clinical studies. Objectives: To investigate how the degree of variability in ARDS measurement commonly reported in clinical studies affects study power, the accuracy of treatment effect estimates, and the measured strength of risk factor associations. Methods: We examined the effect of ARDS measurement error in randomized clinical trials (RCTs) of ARDS-specific treatments and cohort studies using simulations. We varied the reliability of ARDS diagnosis, quantified as the interobserver reliability (κ-statistic) between two reviewers. In RCT simulations, patients identified as having ARDS were enrolled, and when measurement error was present, patients without ARDS could be enrolled. In cohort studies, risk factors as potential predictors were analyzed using reviewer-identified ARDS as the outcome variable. Measurements and Main Results: Lower reliability measurement of ARDS during patient enrollment in RCTs seriously degraded study power. Holding effect size constant, the sample size necessary to attain adequate statistical power increased by more than 50% as reliability declined, although the result was sensitive to ARDS prevalence. In a 1,400-patient clinical trial, the sample size necessary to maintain similar statistical power increased to over 1,900 when reliability declined from perfect to substantial (κ = 0.72). Lower reliability measurement diminished the apparent effectiveness of an ARDS-specific treatment from a 15.2% (95% confidence interval, 9.4–20.9%) absolute risk reduction in mortality to 10.9% (95% confidence interval, 4.7–16.2%) when reliability declined to moderate (κ = 0.51). In cohort studies, the effect on risk factor associations was similar. Conclusions: ARDS measurement error can seriously degrade statistical power and effect size estimates of clinical studies. The reliability of ARDS measurement warrants careful attention in future ARDS clinical studies. PMID:27159648
Have Clinical Trials Properly Assessed c-Met Inhibitors?
Hughes, Veronica S; Siemann, Dietmar W
2018-02-01
The c-Met/HGF pathway is implicated in cancer progression and dissemination. Many inhibitors have been developed to target this pathway. Unfortunately, most trials have failed to demonstrate efficacy. However, clinical trials have not adequately tested the concept of c-Met pathway inhibition due to the lack of appropriate patient selection criteria. Copyright © 2017 Elsevier Inc. All rights reserved.
Windows of Opportunity for Lifestyle Interventions to Prevent Gestational Diabetes Mellitus.
Phelan, Suzanne
2016-11-01
Gestational diabetes mellitus (GDM) is linked with several acute maternal health risks and long-term development of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM similarly increases offspring risk of early-life health complications and later disease. GDM recurrence is common, affecting 40 to 73% of women, and augments associated maternal/fetal/child health risks. Modifiable and independent risk factors for GDM include maternal excessive gestational weight gain and prepregnancy overweight and obesity. Lifestyle interventions that target diet, activity, and behavioral strategies can effectively modify body weight. Randomized clinical trials testing the effects of lifestyle interventions during pregnancy to reduce excessive gestational weight gain have generally shown mixed effects on reducing GDM incidence. Trials testing the effects of postpartum lifestyle interventions among women with a history of GDM have shown reduced incidence of diabetes and improved cardiovascular disease risk factors. However, the long-term effects of interpregnancy or prepregnancy lifestyle interventions on subsequent GDM remain unknown. Future adequately powered and well-controlled clinical trials are needed to determine the effects of lifestyle interventions to prevent GDM and identify pathways to effectively reach reproductive-aged women across all levels of society, before, during, and after pregnancy. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Do Implant Overdentures Improve Dietary Intake? A Randomized Clinical Trial
Hamdan, N.M.; Gray-Donald, K.; Awad, M.A.; Johnson-Down, L.; Wollin, S.; Feine, J.S.
2013-01-01
People wearing mandibular two-implant overdentures (IOD) chew food with less difficulty than those wearing conventional complete dentures (CD). However, there is still controversy over whether or not this results in better dietary intake. In this randomized clinical trials (RCT), the amounts of total dietary fiber (TDF), macronutrients, 9 micronutrients, and energy in diets consumed by persons with IOD and CD were compared. Male and female edentate patients ≥ 65 yrs (n = 255) were randomly divided into 2 groups and assigned to receive a maxillary CD and either a mandibular IOD or a CD. One year following prosthesis delivery, 217 participants (CD = 114, IOD = 103) reported the food and quantities they consumed to a registered dietician through a standard 24-hour dietary recall method. The mean and median values of TDF, macro- and micronutrients, and energy consumed by both groups were calculated and compared analytically. No significant between-group differences were found (ps > .05). Despite quality-of-life benefits from IODs, this adequately powered study reveals no evidence of nutritional advantages for independently living medically healthy edentate elders wearing two-implant mandibular overdentures over those wearing conventional complete dentures in their dietary intake at one year following prosthesis delivery (International Clinical Trials ISRCTN24273915). PMID:24158335
Sit, Regina WS; Chung, Vincent CH; Reeves, Kenneth D.; Rabago, David; Chan, Keith KW; Chan, Dicken CC; Wu, Xinyin; Ho, Robin ST; Wong, Samuel YS
2016-01-01
Hypertonic dextrose injections (prolotherapy) is an emerging treatment for symptomatic knee osteoarthritis (OA) but its efficacy is uncertain. We conducted a systematic review with meta-analysis to synthesize clinical evidence on the effect of prolotherapy for knee OA. Fifteen electronic databases were searched from their inception to September 2015. The primary outcome of interest was score change on the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Three randomized controlled trials (RCTs) of moderate risk of bias and one quasi–randomized trial were included, with data from a total of 258 patients. In the meta-analysis of two eligible studies, prolotherapy is superior to exercise alone by a standardized mean difference (SMD) of 0.81 (95% CI: 0.18 to 1.45, p = 0.012), 0.78 (95% CI: 0.25 to 1.30, p = 0.001) and 0.62 (95% CI: 0.04 to 1.20, p = 0.035) on the WOMAC composite scale; and WOMAC function and pain subscale scores respectively. Moderate heterogeneity exists in all cases. Overall, prolotherapy conferred a positive and significant beneficial effect in the treatment of knee OA. Adequately powered, longer-term trials with uniform end points are needed to better elucidate the efficacy of prolotherapy. PMID:27146849
Ekici, Gamze; Unal, Edibe; Akbayrak, Turkan; Vardar-Yagli, Naciye; Yakut, Yavuz; Karabulut, Erdem
2017-01-01
The authors of this study compared the effects of pilates exercises and connective tissue massage (CTM) on pain intensity; pain-pressure threshold; and tolerance, anxiety, progress, and health-related quality of life in females with fibromyalgia. It was a pilot, assessor masked, randomized controlled trial conducted between January and August of 2013. Twenty-one women with fibromyalgia were randomly assigned to the pilates exercise program (six of whom did not complete the program), and 22 were randomly assigned to CTM (one of whom did not complete this program). Each group received the assigned intervention three times per week during a 4-week period. The Visual Analogue Scale, algometry, State-Trait Anxiety Inventory, Fibromyalgia Impact Questionnaire, and Nottingham Health Profile were used at baseline and at the end of treatments. Significant improvements were found in both groups for all parameters. However, the scores for pain-pressure threshold were significantly elevated and the symptoms of anxiety were significantly diminished in the exercise group compared to the massage group. Thus, exercise and massage might be used to provide improvements in women with fibromyalgia. The exercise group showed more advantages than the massage group and thus might be preferred for patients with fibromyalgia. However, an adequately powered trial is required to determine this with certainty.
Role of phenotypic and genetic testing in managing clopidogrel therapy.
Chan, Noel C; Eikelboom, John W; Ginsberg, Jeffrey S; Lauw, Mandy N; Vanassche, Thomas; Weitz, Jeffrey I; Hirsh, Jack
2014-07-31
The P2Y12 inhibitors, clopidogrel, prasugrel, and ticagrelor, are administered in fixed doses without laboratory monitoring. Randomized trials in acute coronary syndrome have shown that prasugrel and ticagrelor are more effective than standard-dose clopidogrel. Nonetheless, standard-dose clopidogrel remains widely used because it causes less bleeding and is less expensive. Patients treated with standard-dose clopidogrel have substantial variability in platelet inhibition, which is partly explained by genetic polymorphisms encoding CYP2C19, the hepatic enzyme involved in biotransformation of clopidogrel to its active metabolite. Some advocate tailoring P2Y12 inhibitor therapy according to the results of routine laboratory testing. Although there is good evidence for analytic, biological, and clinical validity of several phenotypic and genotypic biomarkers, the benefit of a management strategy that incorporates routine biomarker testing over standard of care without such testing remains unproven. Appropriately designed, adequately powered trials are needed but face the challenges of feasibility, cost, and the progressive switch from clopidogrel to prasugrel or ticagrelor. © 2014 by The American Society of Hematology.
Bitter melon (Momordica charantia): a review of efficacy and safety.
Basch, Ethan; Gabardi, Steven; Ulbricht, Catherine
2003-02-15
The pharmacology, clinical efficacy, adverse effects, drug interactions, and place in therapy of bitter melon are described. Bitter melon (Momordica charantia) is an alternative therapy that has primarily been used for lowering blood glucose levels in patients with diabetes mellitus. Components of bitter melon extract appear to have structural similarities to animal insulin. Antiviral and antineoplastic activities have also been reported in vitro. Four clinical trials found bitter melon juice, fruit, and dried powder to have a moderate hypoglycemic effect. These studies were small and were not randomized or double-blind, however. Reported adverse effects of bitter melon include hypoglycemic coma and convulsions in children, reduced fertility in mice, a favism-like syndrome, increases in gamma-glutamyltransferase and alkaline phosphatase levels in animals, and headaches. Bitter melon may have additive effects when taken with other glucose-lowering agents. Adequately powered, randomized, placebo-controlled trials are needed to properly assess safety and efficacy before bitter melon can be routinely recommended. Bitter melon may have hypoglycemic effects, but data are not sufficient to recommend its use in the absence of careful supervision and monitoring.
Warren-Gash, Charlotte; Forbes, Harriet; Breuer, Judith; Hayward, Andrew C; Mavrodaris, Angelique; Ridha, Basil H; Rossor, Martin; Thomas, Sara L; Smeeth, Liam
2017-06-23
Persisting neurotropic viruses are proposed to increase the risk of dementia, but evidence of association from robust, adequately powered population studies is lacking. This is essential to inform clinical trials of targeted preventive interventions. We will carry out a comprehensive systematic review of published and grey literature of the association between infection with, reactivation of, vaccination against or treatment of any of the eight human herpesviruses and dementia or mild cognitive impairment. We will search the Cochrane Library, Embase, Global Health, Medline, PsycINFO, Scopus, Web of Science, clinical trials registers, the New York Academy of Medicine Grey Literature Report, Electronic Theses Online Service through the British Library and the ISI Conference Proceedings Citation Index for randomised controlled trials, cohort, caseâ€"control, case crossover or self-controlled case series studies reported in any language up to January 2017. Titles, abstracts and full-text screening will be conducted by two researchers independently. Data will be extracted systematically from eligible studies using a piloted template. We will assess risk of bias of individual studies in line with the Cochrane Collaboration tool. We will conduct a narrative synthesis, grouping studies by exposure and outcome definitions, and will describe any differences by population subgroups and dementia subtypes. We will consider performing meta-analyses if there are adequate numbers of sufficiently homogeneous studies. The overall quality of cumulative evidence will be assessed using selected Grading of Recommendations, Assessment, Development and Evaluations criteria. As this is a review of existing studies, no ethical approval is required. Results will be disseminated through a peer-reviewed publication and at national and international conferences. We anticipate the review will clarify the current extent and quality of evidence for a link between herpesviruses and dementia, identify gaps and inform the direction of future research. CRD42017054684. © 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.
Onasanya, Oluwadamilola; Iyer, Geetha; Lucas, Eleanor; Lin, Dora; Singh, Sonal; Alexander, G Caleb
2016-11-01
Given the conflicting evidence regarding the association between exogenous testosterone and cardiovascular events, we systematically assessed published systematic reviews for evidence of the association between exogenous testosterone and cardiovascular events. We searched PubMed, MEDLINE, Embase, Cochrane Collaboration Clinical Trials, ClinicalTrials.gov, and the US Food and Drug Administration website for systematic reviews of randomised controlled trials published up to July 19, 2016. Two independent reviewers screened 954 full texts from 29 335 abstracts to identify systematic reviews of randomised controlled trials in which the cardiovascular effects of exogenous testosterone on men aged 18 years or older were examined. We extracted data for study characteristics, analytic methods, and key findings, and applied the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist to assess methodological quality of each review. Our primary outcome measure was the direction and magnitude of association between exogenous testosterone and cardiovascular events. We identified seven reviews and meta-analyses, which had substantial clinical heterogeneity, differing statistical methods, and variable methodological quality and quality of data abstraction. AMSTAR scores ranged from 3 to 9 out of 11. Six systematic reviews that each included a meta-analysis showed no significant association between exogenous testosterone and cardiovascular events, with summary estimates ranging from 1·07 to 1·82 and imprecise confidence intervals. Two of these six meta-analyses showed increased risk in subgroup analyses of oral testosterone and men aged 65 years or older during their first treatment year. One meta-analysis showed a significant association between exogenous testosterone and cardiovascular events, in men aged 18 years or older generally, with a summary estimate of 1·54 (95% CI 1·09-2·18). Our optimal information size analysis showed that any randomised controlled trial aiming to detect a true difference in cardiovascular risk between treatment groups receiving exogenous testosterone and their controls (with a two-sided p value of 0·05 and a power of 80%) would require at least 17 664 participants in each trial group. Therefore, given the challenge of adequately powering clinical trials for rare outcomes, rigorous observational studies are needed to clarify the association between testosterone-replacement therapy and major adverse cardiovascular outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.
van den Bogert, Cornelis A; Souverein, Patrick C; Brekelmans, Cecile T M; Janssen, Susan W J; Koëter, Gerard H; Leufkens, Hubert G M; Bouter, Lex M
2017-08-01
The objective of the study was to identify the reasons for discontinuation of clinical drug trials and to evaluate whether efficacy-related discontinuations were adequately planned in the trial protocol. All clinical drug trials in the Netherlands, reviewed by institutional review boards in 2007, were followed until December 2015. Data were obtained through the database of the Dutch competent authority (Central Committee on Research Involving Human Subjects [CCMO]) and a questionnaire to the principal investigators. Reasons for trial discontinuation were the primary outcome of the study. Three reasons for discontinuation were analyzed separately: all cause, recruitment failure, and efficacy related (when an interim analysis had demonstrated futility or superiority). Among the efficacy-related discontinuations, we examined whether the data monitoring committee, the stopping rule, and the moment of the interim analysis in the trial progress were specified in the trial protocol. Of the 574 trials, 102 (17.8%) were discontinued. The most common reasons were recruitment failure (33 of 574; 5.7%) and solely efficacy related (30 of 574; 5.2%). Of the efficacy-related discontinuations, 10 of 30 (33.3%) of the trial protocols reported all three aspects in the trial protocol, and 20 of 30 (66.7%) reported at least one aspect in the trial protocol. One out of five clinical drug trials is discontinued before the planned trial end, with recruitment failure and futility as the most common reasons. The target sample size of trials should be feasible, and interim analyses should be adequately described in trial protocols. Copyright © 2017 Elsevier Inc. All rights reserved.
Dafni, Urania; Karlis, Dimitris; Pedeli, Xanthi; Bogaerts, Jan; Pentheroudakis, George; Tabernero, Josep; Zielinski, Christoph C; Piccart, Martine J; de Vries, Elisabeth G E; Latino, Nicola Jane; Douillard, Jean-Yves; Cherny, Nathan I
2017-01-01
The European Society for Medical Oncology (ESMO) has developed the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS), a tool to assess the magnitude of clinical benefit from new cancer therapies. Grading is guided by a dual rule comparing the relative benefit (RB) and the absolute benefit (AB) achieved by the therapy to prespecified threshold values. The ESMO-MCBS v1.0 dual rule evaluates the RB of an experimental treatment based on the lower limit of the 95%CI (LL95%CI) for the hazard ratio (HR) along with an AB threshold. This dual rule addresses two goals: inclusiveness: not unfairly penalising experimental treatments from trials designed with adequate power targeting clinically meaningful relative benefit; and discernment: penalising trials designed to detect a small inconsequential benefit. Based on 50 000 simulations of plausible trial scenarios, the sensitivity and specificity of the LL95%CI rule and the ESMO-MCBS dual rule, the robustness of their characteristics for reasonable power and range of targeted and true HRs, are examined. The per cent acceptance of maximal preliminary grade is compared with other dual rules based on point estimate (PE) thresholds for RB. For particularly small or particularly large studies, the observed benefit needs to be relatively big for the ESMO-MCBS dual rule to be satisfied and the maximal grade awarded. Compared with approaches that evaluate RB using the PE thresholds, simulations demonstrate that the MCBS approach better exhibits the desired behaviour achieving the goals of both inclusiveness and discernment. RB assessment using the LL95%CI for HR rather than a PE threshold has two advantages: it diminishes the probability of excluding big benefit positive studies from achieving due credit and, when combined with the AB assessment, it increases the probability of downgrading a trial with a statistically significant but clinically insignificant observed benefit.
Dafni, Urania; Karlis, Dimitris; Pedeli, Xanthi; Bogaerts, Jan; Pentheroudakis, George; Tabernero, Josep; Zielinski, Christoph C; Piccart, Martine J; de Vries, Elisabeth G E; Latino, Nicola Jane; Douillard, Jean-Yves; Cherny, Nathan I
2017-01-01
Background The European Society for Medical Oncology (ESMO) has developed the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS), a tool to assess the magnitude of clinical benefit from new cancer therapies. Grading is guided by a dual rule comparing the relative benefit (RB) and the absolute benefit (AB) achieved by the therapy to prespecified threshold values. The ESMO-MCBS v1.0 dual rule evaluates the RB of an experimental treatment based on the lower limit of the 95%CI (LL95%CI) for the hazard ratio (HR) along with an AB threshold. This dual rule addresses two goals: inclusiveness: not unfairly penalising experimental treatments from trials designed with adequate power targeting clinically meaningful relative benefit; and discernment: penalising trials designed to detect a small inconsequential benefit. Methods Based on 50 000 simulations of plausible trial scenarios, the sensitivity and specificity of the LL95%CI rule and the ESMO-MCBS dual rule, the robustness of their characteristics for reasonable power and range of targeted and true HRs, are examined. The per cent acceptance of maximal preliminary grade is compared with other dual rules based on point estimate (PE) thresholds for RB. Results For particularly small or particularly large studies, the observed benefit needs to be relatively big for the ESMO-MCBS dual rule to be satisfied and the maximal grade awarded. Compared with approaches that evaluate RB using the PE thresholds, simulations demonstrate that the MCBS approach better exhibits the desired behaviour achieving the goals of both inclusiveness and discernment. Conclusions RB assessment using the LL95%CI for HR rather than a PE threshold has two advantages: it diminishes the probability of excluding big benefit positive studies from achieving due credit and, when combined with the AB assessment, it increases the probability of downgrading a trial with a statistically significant but clinically insignificant observed benefit. PMID:29067214
Hamley, Steven
2017-05-19
A cornerstone of conventional dietary advice is the recommendation to replace saturated fatty acids (SFA) with mostly n-6 polyunsaturated fatty acids (PUFA) to reduce the risk of coronary heart disease (CHD). Many clinical trials aimed to test this advice and have had their results pooled in several meta-analyses. However, earlier meta-analyses did not sufficiently account for major confounding variables that were present in some of those trials. Therefore, the aim of the study was to account for the major confounding variables in the diet heart trials, and emphasise the results from those trials that most accurately test the effect of replacing SFA with mostly n-6 PUFA. Clinical trials were identified from earlier meta-analyses. Relevant trials were categorised as 'adequately controlled' or 'inadequately controlled' depending on whether there were substantial dietary or non-dietary differences between the experimental and control groups that were not related to SFA or mostly n-6 PUFA intake, then were subject to different subgroup analyses. When pooling results from only the adequately controlled trials there was no effect for major CHD events (RR = 1.06, CI = 0.86-1.31), total CHD events (RR = 1.02, CI = 0.84-1.23), CHD mortality (RR = 1.13, CI = 0.91-1.40) and total mortality (RR = 1.07, CI = 0.90-1.26). Whereas, the pooled results from all trials, including the inadequately controlled trials, suggested that replacing SFA with mostly n-6 PUFA would significantly reduce the risk of total CHD events (RR = 0.80, CI = 0.65-0.98, P = 0.03), but not major CHD events (RR = 0.87, CI = 0.70-1.07), CHD mortality (RR = 0.90, CI = 0.70-1.17) and total mortality (RR = 1.00, CI = 0.90-1.10). Available evidence from adequately controlled randomised controlled trials suggest replacing SFA with mostly n-6 PUFA is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately controlled trials. These findings have implications for current dietary recommendations.
Reporting non-adherence in cluster randomised trials: A systematic review.
Agbla, Schadrac C; DiazOrdaz, Karla
2018-06-01
Treatment non-adherence in randomised trials refers to situations where some participants do not receive their allocated treatment as intended. For cluster randomised trials, where the unit of randomisation is a group of participants, non-adherence may occur at the cluster or individual level. When non-adherence occurs, randomisation no longer guarantees that the relationship between treatment receipt and outcome is unconfounded, and the power to detect the treatment effects in intention-to-treat analysis may be reduced. Thus, recording adherence and estimating the causal treatment effect adequately are of interest for clinical trials. To assess the extent of reporting of non-adherence issues in published cluster trials and to establish which methods are currently being used for addressing non-adherence, if any, and whether clustering is accounted for in these. We systematically reviewed 132 cluster trials published in English in 2011 previously identified through a search in PubMed. One-hundred and twenty three cluster trials were included in this systematic review. Non-adherence was reported in 56 cluster trials. Among these, 19 reported a treatment efficacy estimate: per protocol in 15 and as treated in 4. No study discussed the assumptions made by these methods, their plausibility or the sensitivity of the results to deviations from these assumptions. The year of publication of the cluster trials included in this review (2011) could be considered a limitation of this study; however, no new guidelines regarding the reporting and the handling of non-adherence for cluster trials have been published since. In addition, a single reviewer undertook the data extraction. To mitigate this, a second reviewer conducted a validation of the extraction process on 15 randomly selected reports. Agreement was satisfactory (93%). Despite the recommendations of the Consolidated Standards of Reporting Trials statement extension to cluster randomised trials, treatment adherence is under-reported. Among the trials providing adherence information, there was substantial variation in how adherence was defined, handled and reported. Researchers should discuss the assumptions required for the results to be interpreted causally and whether these are scientifically plausible in their studies. Sensitivity analyses to study the robustness of the results to departures from these assumptions should be performed.
Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.
Simpson, Len Parker; Kordi, Mehdi
2017-07-01
Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.
Seiler, CM; Fröhlich, BE; Veit, JA; Gazyakan, E; Wente, MN; Wollermann, C; Deckert, A; Witte, S; Victor, N; Buchler, MW; Knaebel, HP
2006-01-01
Background Annually, more than 90000 surgical procedures of the thyroid gland are performed in Germany. Strategies aimed at reducing the duration of the surgical procedure are relevant to patients and the health care system especially in the context of reducing costs. However, new techniques for quick and safe hemostasis have to be tested in clinically relevance randomized controlled trials before a general recommendation can be given. The current standard for occlusion of blood vessels in thyroid surgery is ligatures. Vascular clips may be a safe alternative but have not been investigated in a large RCT. Methods/design CLIVIT (Clips versus Ligatures in Thyroid Surgery) is an investigator initiated, multicenter, patient-blinded, two-group parallel relevance randomized controlled trial designed by the Study Center of the German Surgical Society. Patients scheduled for elective resection of at least two third of the gland for benign thyroid disease are eligible for participation. After surgical exploration patients are randomized intraoperatively into either the conventional ligature group, or into the clip group. The primary objective is to test for a relevant reduction in operating time (at least 15 min) when using the clip technique. Since April 2004, 121 of the totally required 420 patients were randomized in five centers. Discussion As in all trials the different forms of bias have to be considered, and as in this case, a surgical trial, the role of surgical expertise plays a key role, and will be documented and analyzed separately. This is the first randomized controlled multicenter relevance trial to compare different vessel occlusion techniques in thyroid surgery with adequate power and other detailed information about the design as well as framework. If significant, the results might be generalized and may change the current surgical practice. PMID:16948853
Fraser, W; Vendittelli, F; Krauss, I; Bréart, G
1998-02-01
To estimate the effects among nulliparae of early augmentation with amniotomy and oxytocin on caesarean delivery, and on other indicators of maternal and neonatal morbidity including transfusion. Apgar score < 7 at 5 minutes, and admission to the special care nursery. Meta-analysis. Published studies were identified through manual and computerised searches. Two unpublished studies were identified through direct communication with the investigators. Twelve trials were identified which compared a policy of early labour augmentation including amniotomy followed by oxytocin with a less active form of management. Two methodologically unacceptable studies were excluded. Studies were grouped according to whether they admitted only women with abnormal progress (therapy trials: n = 3) or accepted women with normal labour (prevention trials: n = 7). Unstratified analysis did not provide support for the hypothesis that early augmentation reduces the risk of caesarean section (typical odds ratio [OR] 0.9; 95% CI 0.7-1.1). The typical odds ratio for prevention trials was similar to that obtained in the unstratified analysis (typical OR 0.9, 95% CI 0.7-1.2). Although only a small number of women have been randomised in therapy trials, a trend toward a reduction in the rate of caesarean section with early intervention was seen in this group (typical OR 0.6, 95% CI 0.2-1.4). Early augmentation does not appear to provide benefit over a more conservative form of management in the context of care of nulliparous women with mild delays in the progress of labour. In the context of established delay in labour, an active policy of augmentation may reduce the risk of caesarean section. However, only three small trials have been performed in this context, and they do not have adequate power to allow firm conclusions to be drawn.
Hardy, J R; Spruyt, O; Quinn, S J; Devilee, L R; Currow, D C
2014-06-01
An adequately powered, double-blind, multisite, randomised controlled trial has shown no net clinical benefit for subcutaneous ketamine over placebo in the management of cancer pain refractory to combination opioid and co-analgesic therapy. The results of the trial were disseminated widely both nationally and internationally. To determine whether the trial had impacted on clinical practice in Australasia. Members of the Australia and New Zealand Society of Palliative Medicine were sent an online ketamine utilisation survey. A total of 123/392 clinicians responded (31% response rate). The majority of respondents had practised for more than 10 years in a metropolitan hospital setting. Ketamine had been prescribed by 91% of respondents, and 92% were aware of the trial. As a result, 65% of respondents had changed practice (17% no longer prescribed ketamine, 46% used less and 2% more). Thirty-five per cent had not changed practice. Reasons for change included belief in the results of the study, concerns over the toxicity reported or because there were alternatives for pain control. Of those who prescribed less, over 80% were more selective and would now only use the drug in certain clinical situations or pain types, or when all other medications had failed. Although two-thirds of respondents reported practice change as a result of the randomised controlled trial, a minority remained convinced of the benefit of the drug from their own observations and would require additional evidence. © 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.
Publication bias was not a good reason to discourage trials with low power.
Borm, George F; den Heijer, Martin; Zielhuis, Gerhard A
2009-01-01
The objective was to investigate whether it is justified to discourage trials with less than 80% power. Trials with low power are unlikely to produce conclusive results, but their findings can be used by pooling then in a meta-analysis. However, such an analysis may be biased, because trials with low power are likely to have a nonsignificant result and are less likely to be published than trials with a statistically significant outcome. We simulated several series of studies with varying degrees of publication bias and then calculated the "real" one-sided type I error and the bias of meta-analyses with a "nominal" error rate (significance level) of 2.5%. In single trials, in which heterogeneity was set at zero, low, and high, the error rates were 2.3%, 4.7%, and 16.5%, respectively. In multiple trials with 80%-90% power and a publication rate of 90% when the results were nonsignificant, the error rates could be as high as 5.1%. When the power was 50% and the publication rate of non-significant results was 60%, the error rates did not exceed 5.3%, whereas the bias was at most 15% of the difference used in the power calculation. The impact of publication bias does not warrant the exclusion of trials with 50% power.
Effect of Overhydration on Time-Trial Swim Performance.
ERIC Educational Resources Information Center
Maresh, Carl M.; Bergeron, Michael E.; Kenefick, Robert W.; Castellani, John W.; Hoffman, Jay R.; Armstrong, Lawrence E.
2001-01-01
Examined whether moderate overhydration would enhance the performance of otherwise euhydrated collegiate swimmers during two 183-meter time-trial swims held 3 days apart. Participants swam in alternate, randomized euhydrated, and overhydrated states. Results indicated that euhydration before an intense, short-duration swim was adequate for peak…
2011-01-01
Background A healthy start to life requires adequate motor development and physical activity participation. Currently 5-15% of children have impaired motor development without any obvious disorder. These children are at greater risk of obesity, musculoskeletal disorders, low social confidence and poor mental health. Traditional electronic game use may impact on motor development and physical activity creating a vicious cycle. However new virtual reality (VR) game interfaces may provide motor experiences that enhance motor development and lead to an increase in motor coordination and better physical activity and mental health outcomes. VR games are beginning to be used for rehabilitation, however there is no reported trial of the impact of these games on motor coordination in children with developmental coordination disorder. Methods This cross-over randomised and controlled trial will examine whether motor coordination is enhanced by access to active electronic games and whether daily activity, attitudes to physical activity and mental health are also enhanced. Thirty children aged 10-12 years with poor motor coordination (≤ 15th percentile) will be recruited and randomised to a balanced ordering of 'no active electronic games' and 'active electronic games'. Each child will participate in both conditions for 16 weeks, and be assessed prior to participation and at the end of each condition. The primary outcome is motor coordination, assessed by kinematic and kinetic motion analysis laboratory measures. Physical activity and sedentary behaviour will be assessed by accelerometry, coordination in daily life by parent report questionnaire and attitudes to physical activity, self-confidence, anxiety and depressed mood will be assessed by self report questionnaire. A sample of 30 will provide a power of > 0.9 for detecting a 5 point difference in motor coordination on the MABC-2 TIS scale (mean 17, sd = 5). Discussion This is the first trial to examine the impact of new virtual reality games on motor coordination in children with developmental coordination disorder. The findings will provide critical information to understand whether these electronic games can be used to have a positive impact on the physical and mental health of these children. Given the importance of adequate motor coordination, physical activity and mental health in childhood, this project can inform interventions which could have a profound impact on the long term health of this group of children. Trial registration Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000400965 PMID:21851587
Wesson, Jacqueline; Clemson, Lindy; Brodaty, Henry; Lord, Stephen; Taylor, Morag; Gitlin, Laura; Close, Jacqueline
2013-09-03
People with dementia have a disproportionately high rate of falls and fractures and poorer outcomes, yet there is currently no evidence to guide falls prevention in this population. A randomised trial design was used to test feasibility of study components and acceptability of a home hazard reduction and balance and strength exercise fall prevention program. The program was tailored to participant's individual cognitive levels and implemented as a carer-supported intervention. Feasibility of recruitment, retention and implementation of intervention were recorded through observation and documented in field notes. Adherence, carer burden and use of task simplification strategies were also monitored. Outcome measures, collected at 12 weeks included physiological, fear of falling, cognitive and functional measures. Recruitment was achievable but may be more challenging in a multisite trial. Twenty two dyads of persons with mild dementia and their carers were randomised to intervention or usual care control group. Of 38 dyads referred to the study, there was a high rate of willingness to participate, with 6 (16%) declining and 10 (26%) not meeting inclusion criteria. The intervention was well received by participants and carers and adherence to both program components was very good. All participants implemented some home safety recommendations (range 19-80%) with half implementing 50% or more. At the end of 12 weeks, 72% of the intervention group were exercising. Both the rate of falling and the risk of a fall were lower in the intervention group but these findings were not significant (RR= 0.50 (95% CI 0.11-2.19). There were no differences in physiological outcome measures between the control and intervention groups. However results were influenced by the small study size and incomplete data primarily in the intervention group at follow up. The pilot study was feasible and acceptable to people with mild dementia and their carers. The lessons learnt included: recruitment for a larger trial will require multiple approaches; home safety recommendations should provide a greater emphasis on environmental use compared with behavioural change; strategies to ensure an adequate dosage of exercise should be further explored. We recommend that intervention delivery incorporate an integrated occupational therapy and physiotherapy approach and that carers be provided with an individualised session to enhance dementia-specific skills in management and communication. A refined intervention should be tested in a randomised trial with an adequately powered sample size. Australia and New Zealand Clinical Trials Registry 126100001049066.
Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases.
Rambaldi, A; Jacobs, B P; Iaquinto, G; Gluud, C
2005-04-18
Alcohol and hepatotoxic viruses cause the majority of liver diseases. Randomised clinical trials have assessed whether extracts of milk thistle, Silybum marianum (L) Gaertneri, have any effect in patients with alcoholic and/or hepatitis B or C virus liver diseases. To assess the beneficial and harmful effects of milk thistle or milk thistle constituents versus placebo or no intervention in patients with alcoholic liver disease and/or viral liver diseases (hepatitis B and hepatitis C). The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and full text searches were combined (December 2003). Manufacturers and researchers in the field were contacted. Only randomised clinical trials in patients with alcoholic and/or hepatitis B or C virus liver diseases (acute and chronic) were included. Interventions encompassed milk thistle at any dose or duration versus placebo or no intervention. The trials could be double blind, single blind, or unblinded. The trials could be unpublished or published and no language limitations were applied. The primary outcome measure was mortality. Binary outcomes are reported as relative risks (RR) with 95% confidence interval (CI). Subgroup analyses were performed with regard to methodological quality. Thirteen randomised clinical trials assessed milk thistle in 915 patients with alcoholic and/or hepatitis B or C virus liver diseases. The methodological quality was low: only 23% of the trials reported adequate allocation concealment and only 46% were considered adequately double-blinded. Milk thistle versus placebo or no intervention had no significant effect on mortality (RR 0.78, 95% CI 0.53 to 1.15), complications of liver disease (RR 0.95, 95% CI 0.83 to 1.09), or liver histology. Liver-related mortality was significantly reduced by milk thistle in all trials (RR 0.50, 95% CI 0.29 to 0.88), but not in high-quality trials (RR 0.57, 95% CI 0.28 to 1.19). Milk thistle was not associated with a significantly increased risk of adverse events (RR 0.83, 95% CI 0.46 to 1.50). Our results question the beneficial effects of milk thistle for patients with alcoholic and/or hepatitis B or C virus liver diseases and highlight the lack of high-quality evidence to support this intervention. Adequately conducted and reported randomised clinical trials on milk thistle versus placebo are needed.
Levamisole in steroid-sensitive nephrotic syndrome of childhood: the lost paradise?
Davin, J C; Merkus, M P
2005-01-01
Among the different drugs used for sparing steroids in steroid-sensitive nephrotic syndrome (SSNS) with frequent relapses and steroid dependency, levamisole is the least toxic and the least expensive. However, it is neither approved for this indication nor widely used in Europe. This may be explained by the difficulty in obtaining levamisole in some countries and the lack of good quality evidence for its effectiveness. Evidence is limited to three clinical trials that all suffered from methodological limitations. Statistical synthesis of these trials showed that levamisole reduces the risk of a relapse during treatment (relative risk 0.60, 95% confidence interval 0.45-0.79). From the available information, no conclusions can be drawn on the steroid-sparing effect, the long-term efficacy, and safety, as well as possible differences in efficacy in different subgroups of SSNS patients. The confirmation of a favorable effect of levamisole on the reduction of the frequency of relapses and on sparing steroids in an adequately powered, double-blind, placebo-controlled, randomized, multi-center clinical trial will promote consensus on the place of levamisole in the treatment of SSNS of childhood. Follow-up should be at least 1 year to evaluate long-term efficacy and side effects. If the results of such a clinical trial confirm the beneficial effects of levamisole in nephrotic syndrome, this may allow registration for this indication and interest companies other than Jansen-Cilag, which only recently has decided to stop its production.
Chen, Peili; Wu, Xiaoqiang; Wang, Zhiwei; Li, Zhenya; Tian, Xiangyong; Wang, Junpeng; Yan, Tianzhong
2018-06-01
We sought to determine the impact of levosimendan on mortality following cardiac surgery based on large-scale randomized controlled trials (RCTs). We searched PubMed, Web of Science, Cochrane databases, and ClinicalTrials.gov for RCTs published up to December 2017, on levosimendan for patients undergoing cardiac surgery. A total of 25 RCTs enrolling 2960 patients met the inclusion criteria; data from 15 placebo-controlled randomized trials were included for meta-analysis. Pooled analysis showed that the all-cause mortality rate was 6.4% (71 of 1106) in the levosimendan group and 8.4% (93 of 1108) in the placebo group (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.55-1.04; P = 0.09). There were no significant differences between the two groups in the rates of myocardial infarction (OR: 0.91; 95% CI, 0.68-1.21; P = 0.52), serious adverse events (OR: 0.84; 95% CI, 0.66-1.07; P = 0.17), hypotension (OR: 1.69; 95% CI, 0.94-3.03; P = 0.08), and low cardiac output syndrome (OR: 0.47; 95% CI, 0.22-1.02; P = 0.05). Levosimendan did not result in a reduction in mortality in adult cardiac surgery patients. Well designed, adequately powered, multicenter trials are necessary to determine the role of levosimendan in adult cardiac surgery. © 2018 The Authors. Journal of Cardiac Surgery Published by Wiley Periodicals Inc.
Reynolds, Shirley A; Clark, Sarah; Smith, Holly; Langdon, Peter E; Payne, Ruth; Bowers, Gemma; Norton, Elisabeth; McIlwham, Harriet
2013-12-01
Obsessive-compulsive disorder (OCD) in young people can be effectively treated with Cognitive Behavior Therapy (CBT). Practice guidelines in the United Kingdom recommend that CBT be delivered with parental or family involvement; however, there is no evidence from randomized trials that this enhances effectiveness. The aim of this trial was to assess if CBT with high parental involvement was more effective than CBT with low parental involvement (individual CBT) in reducing symptoms of OCD. Fifty young people ages 12-17 years with OCD were randomly allocated to individual CBT or parent-enhanced CBT. In parent-enhanced CBT parents attended all treatment sessions; in individual CBT, parents attended only Sessions 1, 7, and the final session. Participants received up to 14 sessions of CBT. Data were analyzed using intent-to-treat and per-protocol methods. The primary outcome measure was the Children's Yale-Brown Obsessive Compulsion Scale (Scahill et al., 1997). Both forms of CBT significantly reduced symptoms of OCD and anxiety. Change in OCD symptoms was maintained at 6 months. Per-protocol analysis suggested that parent-enhanced CBT may be associated with significantly larger reductions in anxiety symptoms. High and low parental involvement in CBT for OCD in young people were both effective, and there was no evidence that 1 method of delivery was superior on the primary outcome measure. However, this study was small. Future trials should be adequately powered and examine interactions with the age of the young person and comorbid anxiety disorders.
Lomer, Miranda C E; Grainger, Stephen L; Ede, Roland; Catterall, Adrian P; Greenfield, Simon M; Cowan, Russell E; Vicary, F Robin; Jenkins, Anthony P; Fidler, Helen; Harvey, Rory S; Ellis, Richard; McNair, Alistair; Ainley, Colin C; Thompson, Richard P H; Powell, Jonathan J
2005-03-01
Dietary microparticles, which are bacteria-sized and non-biological, found in the modern Western diet, have been implicated in both the aetiology and pathogenesis of Crohn's disease. Following on from the findings of a previous pilot study, we aimed to confirm whether a reduction in the amount of dietary microparticles facilitates induction of remission in patients with active Crohn's disease, in a single-blind, randomized, multi-centre, placebo controlled trial. Eighty-three patients with active Crohn's disease were randomly allocated in a 2 x 2 factorial design to a diet low or normal in microparticles and/or calcium for 16 weeks. All patients received a reducing dose of prednisolone for 6 weeks. Outcome measures were Crohn's disease activity index, Van Hees index, quality of life and a series of objective measures of inflammation including erythrocyte sedimentation rate, C-reactive protein, intestinal permeability and faecal calprotectin. After 16 weeks patients returned to their normal diet and were followed up for a further 36 weeks. Dietary manipulation provided no added effect to corticosteroid treatment on any of the outcome measures during the dietary trial (16 weeks) or follow-up (to 1 year); e.g., for logistic regression of Crohn's disease activity index based rates of remission (P=0.1) and clinical response (P=0.8), in normal versus low microparticle groups. Our adequately powered and carefully controlled dietary trial found no evidence that reducing microparticle intake aids remission in active Crohn's disease.
USDA-ARS?s Scientific Manuscript database
Calcium supplementation is a widely recognized strategy for achieving adequate calcium intake. We designed this blinded, randomized, crossover interventional trial to compare the bioavailability of a new stable synthetic amorphous calcium carbonate (ACC) with that of crystalline calcium carbonate (C...
Maitland, Kathryn; Kiguli, Sarah; Opoka, Robert O.; Olupot-Olupot, Peter; Engoru, Charles; Njuguna, Patricia; Bandika, Victor; Mpoya, Ayub; Bush, Andrew; Williams, Thomas N.; Grieve, Richard; Sadique, Zia; Fraser, John; Harrison, David; Rowan, Kathy
2018-01-01
Background: In Africa, the clinical syndrome of pneumonia remains the leading cause of morbidity and mortality in children in the post-neonatal period. This represents a significant burden on in-patient services. The targeted use of oxygen and simple, non-invasive methods of respiratory support may be a highly cost-effective means of improving outcome, but the optimal oxygen saturation threshold that results in benefit and the best strategy for delivery are yet to be tested in adequately powered randomised controlled trials. There is, however, an accumulating literature about the harms of oxygen therapy across a range of acute and emergency situations that have stimulated a number of trials investigating permissive hypoxia. Methods: In 4200 African children, aged 2 months to 12 years, presenting to 5 hospitals in East Africa with respiratory distress and hypoxia (oxygen saturation < 92%), the COAST trial will simultaneously evaluate two related interventions (targeted use of oxygen with respect to the optimal oxygen saturation threshold for treatment and mode of delivery) to reduce shorter-term mortality at 48-hours (primary endpoint), and longer-term morbidity and mortality to 28 days in a fractional factorial design, that compares: Liberal oxygenation (recommended care) compared with a strategy that permits hypoxia to SpO 2 > or = 80% (permissive hypoxia); andHigh flow using AIrVO 2 TM compared with low flow delivery (routine care). Discussion: The overarching objective is to address the key research gaps in the therapeutic use of oxygen in resource-limited setting in order to provide a better evidence base for future management guidelines. The trial has been designed to address the poor outcomes of children in sub-Saharan Africa, which are associated with high rates of in-hospital mortality, 9-10% (for those with oxygen saturations of 80-92%) and 26-30% case fatality for those with oxygen saturations <80%. Clinical trial registration: ISRCTN15622505 Trial status: Recruiting PMID:29383331
Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo
2015-09-01
The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m(2); maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. The TT5km showed high absolute (coefficient of variation < 3%) and relative (intraclass coefficient correlation > 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg(-1)), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h(-1)). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness.
Stow, Ruth; Rushton, Alison; Ives, Natalie; Smith, Christina; Rick, Caroline
2015-01-01
Protein energy malnutrition predisposes individuals to disease, delays recovery from illness and reduces quality of life. Care home residents are especially vulnerable, with an estimated 30%-42% at risk. There is no internationally agreed protocol for the nutritional treatment of malnutrition in the care home setting. Widely used techniques include food-based intervention and/or the use of prescribed oral nutritional supplements, but a trial comparing the efficacy of interventions is necessary. In order to define outcomes and optimise the design for an adequately powered, low risk of bias cluster randomised controlled trial, a feasibility trial with 6-month intervention is being run, to assess protocol procedures, recruitment and retention rates, consent processes and resident and staff acceptability. Trial recruitment began in September 2013 and concluded in December 2013. Six privately run care homes in Solihull, England, were selected to establish feasibility within different care home types. Residents with or at risk of malnutrition with no existing dietetic intervention in place were considered for receipt of the allocated intervention. Randomisation took place at the care home level, using a computer-generated random number list to allocate each home to either a dietetic intervention arm (food-based or prescribed supplements) or the standard care arm, continued for 6 months. Dietetic intervention aimed to increase daily calorie intake by 600 kcal and protein by 20-25 g. The primary outcomes will be trial feasibility and acceptability of trial design and allocated interventions. A range of outcome assessments and data collection tools will be evaluated for feasibility, including change in nutrient intake, anthropometric parameters and patient-centric measures, such as quality of life and self-perceived appetite. The complexities inherent in care home research has resulted in the under representation of this population in research trials. The results of this feasibility trial will be used to inform the development and design of a future cluster randomised controlled trial to compare food-based intervention with prescribed oral nutritional supplements (ONS) in the treatment of malnutrition within the care home population. Current Controlled Trials ISRCTN38047922.
Dellinger, R Phillip; Schorr, Christa; Trzeciak, Stephen
2011-03-01
Only through adequately designed and adequately conducted clinical trials can new treatments be found for the benefit of the septic patient. Over the past 20 years, tens of thousands of patients have been enrolled in sepsis clinical trials with little success. These efforts, however, have not been without worth. Much has been learned and the knowledge gained has changed our approach to trial design in this very difficult field. Animal studies are better designed to match the clinical picture of severe sepsis. Phase II studies are more carefully engineered to answer questions about the most suitable target population and end points. Trial conduct likely benefits from use of CROs and a CCC. The future of clinical trials may include more standardization of sepsis management across investigative sites. Before the decision is made to become an investigative site in a multicenter industry-sponsored clinical trial in sepsis or severe sepsis, it is important to recognize what is required to succeed. Once these key-to-success elements are in place, members of the investigative team are more likely to realize the satisfaction and career growth from becoming a successful site. The most professional satisfaction comes from the knowledge of contributing to original science in the field of the sepsis. Copyright © 2011 Elsevier Inc. All rights reserved.
Viale, G.; Giobbie-Hurder, A.; Gusterson, B. A.; Maiorano, E.; Mastropasqua, M. G.; Sonzogni, A.; Mallon, E.; Colleoni, M.; Castiglione-Gertsch, M.; Regan, M. M.; Brown, R. W.; Golouh, R.; Crivellari, D.; Karlsson, P.; Öhlschlegel, C.; Gelber, R. D.; Goldhirsch, A.; Coates, A. S.
2010-01-01
Background: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer. Patients and methods: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin–eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years). Results: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy. Conclusion: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy. PMID:19633051
Good isometric and isokinetic power restoration after distal biceps tendon repair with anchors.
Suda, Arnold J; Prajitno, Julia; Grützner, Paul A; Tinelli, Marco
2017-07-01
Distal biceps brachii tendon rupture can lead to 30-40% power loss of elbow flexion and up to 50% of forearm supination. Re-fixation of the distal biceps brachii tendon is recommended to warrant an adequate quality of the patient's life. This study reports the isometric and isokinetic results after anchor re-fixation 2.5 years after surgery. Between 2007 and 2010, 69 patients with distal biceps brachii tendon tear underwent a suture anchor reattachment. During the follow-up examination, a questionnaire and DASH score were filled in, the circumferences of the arm were measured, range of motion was collected, and different trials were conducted at the BTE Primus RS™ (Baltimore Therapeutic Equipment) on both arms. 49 patients (71%) were reinvestigated with a follow-up of 32 months (11-58 months). A significant difference was found in the ability of elbow flexion between the affected arm and the opposite side as well as in pronation and supination. In elbow flexion and extension as well as in pronation and supination of the forearm, the strength was significantly diminished. 32 months after surgical re-fixation of the distal biceps brachii tendon rupture, strength in all exercises is marginally reduced in comparison to the opposite arm. Re-fixation of the distal biceps brachii tendon is an adequate method to return the range of motion and the strength in the elbow joint to an almost normal level and that gives rise to a high level of patient satisfaction. Level III, case-control study.
Omega-3 Fatty acids: anti-arrhythmic, pro-arrhythmic, or both?
von Schacky, C
2012-01-01
This review focuses on developments after 2008, when the topic was last reviewed by the author. Pertinent publications were found by medline searches and in the author's personal data base. Prevention of atrial fibrillation (AF) was investigated in a number of trials, sparked by one positive report on the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), considerations of upstream therapy, data from electrophysiologic laboratories and animal experiments. If EPA + DHA prevent postoperative AF, the effect is probably smaller than initially expected. The same is probably true for maintenance of sinus rhythm after cardioversion and for new-onset AF. Larger trials are currently ongoing. Prevention of ventricular arrhythmias was studied in carriers of an implanted cardioverter-defibrillator, with no clear results. This might have been due to a broad definition of the primary endpoint, including any ventricular arrhythmia and any action of the device. Epidemiologic studies support the contention that high levels of EPA + DHA prevent sudden cardiac death (SCD). However, since SCD is a rare occurrence, it is difficult to conduct an adequately powered trial. In patients with congestive heart failure, EPA + DHA reduced total mortality and rehospitalizations, but not SCD or presumed arrhythmic death. Of three trials in patients after a myocardial infarction, two were inadequately powered, and in one, the dose might have been too low. Taken together, while epidemiologic studies support an inverse relation between EPA + DHA and occurrence of SCD or arrhythmic death, demonstrating this effect in intervention trials remained elusive so far. A pro-arrhythmic effect of EPA + DHA has not been seen in intervention studies, and results of epidemiologic and animal studies also rather argue against such an effect. A different, and probably more productive, perspective is provided by a standardized analytical assessment of a person's status in EPA + DHA by use of the omega-3 index, EPA + DHA in red cell fatty acids. In populations with a high omega-3 index, SCD is rare. Intervention trials can become more effective by including a low omega-3 index into the inclusion criteria, thus creating a study population more likely to demonstrate an effect of EPA + DHA. This is especially relevant in case of rare endpoints, like new-onset AF or SCD.
Omega-3 Fatty Acids: Anti-Arrhythmic, Pro-Arrhythmic, or Both?
von Schacky, C.
2012-01-01
This review focuses on developments after 2008, when the topic was last reviewed by the author. Pertinent publications were found by medline searches and in the author’s personal data base. Prevention of atrial fibrillation (AF) was investigated in a number of trials, sparked by one positive report on the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), considerations of upstream therapy, data from electrophysiologic laboratories and animal experiments. If EPA + DHA prevent postoperative AF, the effect is probably smaller than initially expected. The same is probably true for maintenance of sinus rhythm after cardioversion and for new-onset AF. Larger trials are currently ongoing. Prevention of ventricular arrhythmias was studied in carriers of an implanted cardioverter-defibrillator, with no clear results. This might have been due to a broad definition of the primary endpoint, including any ventricular arrhythmia and any action of the device. Epidemiologic studies support the contention that high levels of EPA + DHA prevent sudden cardiac death (SCD). However, since SCD is a rare occurrence, it is difficult to conduct an adequately powered trial. In patients with congestive heart failure, EPA + DHA reduced total mortality and rehospitalizations, but not SCD or presumed arrhythmic death. Of three trials in patients after a myocardial infarction, two were inadequately powered, and in one, the dose might have been too low. Taken together, while epidemiologic studies support an inverse relation between EPA + DHA and occurrence of SCD or arrhythmic death, demonstrating this effect in intervention trials remained elusive so far. A pro-arrhythmic effect of EPA + DHA has not been seen in intervention studies, and results of epidemiologic and animal studies also rather argue against such an effect. A different, and probably more productive, perspective is provided by a standardized analytical assessment of a person’s status in EPA + DHA by use of the omega-3 index, EPA + DHA in red cell fatty acids. In populations with a high omega-3 index, SCD is rare. Intervention trials can become more effective by including a low omega-3 index into the inclusion criteria, thus creating a study population more likely to demonstrate an effect of EPA + DHA. This is especially relevant in case of rare endpoints, like new-onset AF or SCD. PMID:22529815
Intrahepatic Cholangiocarcinoma: expert consensus statement
Weber, Sharon M; Ribero, Dario; O=Reilly, Eileen M; Kokudo, Norihiro; Miyazaki, Masaru; Pawlik, Timothy M
2015-01-01
An American Hepato-Pancreato-Biliary Association (AHPBA)-sponsored consensus meeting of expert panellists met on 15 January 2014 to review current evidence on the management of intrahepatic cholangiocarcinoma (ICC) in order to establish practice guidelines and to agree on consensus statements. The treatment of ICC requires a coordinated, multidisciplinary approach to optimize survival. Biopsy is not necessary if the surgeon suspects ICC and is planning curative resection, although biopsy should be obtained before systemic or locoregional therapies are initiated. Assessment of resectability is best accomplished using cross-sectional imaging [computed tomography (CT) or magnetic resonance imaging (MRI)], but the role of positron emission tomography (PET) is unclear. Resectability in ICC is defined by the ability to completely remove the disease while leaving an adequate liver remnant. Extrahepatic disease, multiple bilobar or multicentric tumours, and lymph node metastases beyond the primary echelon are contraindications to resection. Regional lymphadenectomy should be considered a standard part of surgical therapy. In patients with high-risk features, the routine use of diagnostic laparoscopy is recommended. The preoperative diagnosis of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC–CC) by imaging studies is extremely difficult. Surgical resection remains the mainstay of treatment, but survival is worse than in HCC alone. There are no adequately powered, randomized Phase III trials that can provide definitive recommendations for adjuvant therapy for ICC. Patients with high-risk features (lymphovascular invasion, multicentricity or satellitosis, large tumours) should be encouraged to enrol in clinical trials and to consider adjuvant therapy. Cisplatin plus gemcitabine represents the standard-of-care, front-line systemic therapy for metastatic ICC. Genomic analyses of biliary cancers support the development of targeted therapeutic interventions. PMID:26172134
Voils, Corrine I; Levine, Erica; Gierisch, Jennifer M; Pendergast, Jane; Hale, Sarah L; McVay, Megan A; Reed, Shelby D; Yancy, William S; Bennett, Gary; Strawbridge, Elizabeth M; White, Allison C; Shaw, Ryan J
2018-02-01
The obesity epidemic has negative physical, psychological, and financial consequences. Despite the existence of effective behavioral weight loss interventions, many individuals do not achieve adequate weight loss, and most regain lost weight in the year following intervention. We report the rationale and design for a 2×2 factorial study that involves financial incentives for dietary self-monitoring (yes vs. no) and/or interim weight loss (yes vs. no). Outpatients with obesity participate in a 24-week, group-based weight loss intervention. All participants are asked to record their daily dietary and liquid intake on a smartphone application (app) and to weigh themselves daily at home on a study-provided cellular scale. An innovative information technology (IT) solution collates dietary data from the app and weight from the scale. Using these data, an algorithm classifies participants weekly according to whether they met their group's criteria to receive a cash reward ranging from $0 to $30 for dietary self-monitoring and/or interim weight loss. Notice of the reward is provided via text message, and credit is uploaded to a gift card. This pilot study will provide information on the feasibility of using this novel IT solution to provide variable-ratio financial incentives in real time via its effects on recruitment, intervention adherence, retention, and cost. This study will provide the foundation for a comprehensive, adequately-powered, randomized controlled trial to promote short-term weight loss and long-term weight maintenance. If efficacious, this approach could reduce the prevalence, adverse outcomes, and costs of obesity for millions of Americans. Clinicaltrials.gov registration: NCT02691260. Published by Elsevier Inc.
Camperdown Program for Adults Who Stutter: A Student Training Clinic Phase I Trial
ERIC Educational Resources Information Center
Cocomazzo, Nadia; Block, Susan; Carey, Brenda; O'Brian, Sue; Onslow, Mark; Packman, Ann; Iverach, Lisa
2012-01-01
Objectives: During speech pathology professional preparation there is a need for adequate student instruction with speech-restructuring treatments for adults. An important part of that clinical educational experience is to participate in a clinical setting that produces outcomes equivalent to those attained during clinical trials. A previous…
Joint probability of statistical success of multiple phase III trials.
Zhang, Jianliang; Zhang, Jenny J
2013-01-01
In drug development, after completion of phase II proof-of-concept trials, the sponsor needs to make a go/no-go decision to start expensive phase III trials. The probability of statistical success (PoSS) of the phase III trials based on data from earlier studies is an important factor in that decision-making process. Instead of statistical power, the predictive power of a phase III trial, which takes into account the uncertainty in the estimation of treatment effect from earlier studies, has been proposed to evaluate the PoSS of a single trial. However, regulatory authorities generally require statistical significance in two (or more) trials for marketing licensure. We show that the predictive statistics of two future trials are statistically correlated through use of the common observed data from earlier studies. Thus, the joint predictive power should not be evaluated as a simplistic product of the predictive powers of the individual trials. We develop the relevant formulae for the appropriate evaluation of the joint predictive power and provide numerical examples. Our methodology is further extended to the more complex phase III development scenario comprising more than two (K > 2) trials, that is, the evaluation of the PoSS of at least k₀ (k₀≤ K) trials from a program of K total trials. Copyright © 2013 John Wiley & Sons, Ltd.
Sajatovic, Martha; Ross, Ruth; Legacy, Susan N; Byerly, Matthew; Kane, John M; DiBiasi, Faith; Fitzgerald, Heather; Correll, Christoph U
2018-01-01
The aim of this study was to provide recommendations on initiating and maintaining long-acting injectable antipsychotics (LAIs) in individuals with schizophrenia/schizoaffective or bipolar disorder. A 50-question survey comprising 916 response options was completed by 34 expert researchers and high prescribers with extensive LAI experience, rating relative appropriateness/importance on a 9-point scale. Consensus was determined using chi-square test of score distributions. Results of 21 questions comprising 339 response options regarding LAI initiation, maintenance treatment, adequate trial definition, identifying treatment nonresponse, and switching are reported. Experts agreed that the most important LAI selection factor was patient response/tolerability to previous antipsychotics. An adequate therapeutic LAI trial was defined as the time to steady state ± 1-2 injection cycles. Experts suggested that oral efficacy and tolerability should be established before switching to an LAI, without consensus on the required time, and that the time for oral supplementation and next injection interval should be determined by the time to attainment of therapeutic LAI levels. Most experts agreed that ≥1 adequate LAI trial is needed to identify the lack of efficacy. There was little agreement about strategies for switching between LAIs. Expert guidance may aid clinicians in their decisions regarding initiating/maintaining LAIs in individuals with schizophrenia/schizoaffective or bipolar disorder.
Negrão, Luis; Nunes, Paula
2016-01-01
Carpal tunnel syndrome is the most common type of peripheral entrapment neuropathy. We performed an exploratory, open-label, multicenter, observational study of 48 patients with peripheral entrapment neuropathy. Patients received a daily capsule of uridine monophosphate, folic acid + vitamin B12 for 2 months and were evaluated using the Pain DETECT questionnaire. The global score for pain decreased from 17.3 ± 5.9 at baseline to 10.3 ± 6.1 at the final evaluation (p < 0.001). Concomitant analgesic and anti-inflammatory treatment was stopped or the dose reduced in 77.4% of patients. Uridine monophosphate + folic acid + vitamin B12 reduced total pain score, intensity and characterization of pain and associated symptoms. These results should be tested in a well-designed, adequately powered randomized controlled trial.
Froud, Robert; Rajendran, Dévan; Patel, Shilpa; Bright, Philip; Bjørkli, Tom; Eldridge, Sandra; Buchbinder, Rachelle; Underwood, Martin
2017-06-01
A systematic review of nonspecific low back pain trials published between 1980 and 2012. To explore what proportion of trials have been powered to detect different bands of effect size; whether there is evidence that sample size in low back pain trials has been increasing; what proportion of trial reports include a sample size calculation; and whether likelihood of reporting sample size calculations has increased. Clinical trials should have a sample size sufficient to detect a minimally important difference for a given power and type I error rate. An underpowered trial is one within which probability of type II error is too high. Meta-analyses do not mitigate underpowered trials. Reviewers independently abstracted data on sample size at point of analysis, whether a sample size calculation was reported, and year of publication. Descriptive analyses were used to explore ability to detect effect sizes, and regression analyses to explore the relationship between sample size, or reporting sample size calculations, and time. We included 383 trials. One-third were powered to detect a standardized mean difference of less than 0.5, and 5% were powered to detect less than 0.3. The average sample size was 153 people, which increased only slightly (∼4 people/yr) from 1980 to 2000, and declined slightly (∼4.5 people/yr) from 2005 to 2011 (P < 0.00005). Sample size calculations were reported in 41% of trials. The odds of reporting a sample size calculation (compared to not reporting one) increased until 2005 and then declined (Equation is included in full-text article.). Sample sizes in back pain trials and the reporting of sample size calculations may need to be increased. It may be justifiable to power a trial to detect only large effects in the case of novel interventions. 3.
Polysaccharide vaccines for preventing serogroup A meningococcal meningitis.
Patel, M; Lee, C K
2001-01-01
Controlled trials over two decades ago showed that the polysaccharide vaccine prevented serogroup A meningococcal meningitis. Subsequent non-experimental studies suggested age-specific variations in the duration of protection among young children. To determine the effect of polysaccharide serogroup A vaccine for preventing serogroup A meningococcal meningitis. MEDLINE and the Cochrane Controlled Trials Register. The first stage of the review included prospective controlled trials. The second stage included non-experimental studies that addressed questions unanswered by the trials, i.e. the duration of protection and the effect of a booster dose in children under 2 years of age. One reviewer assessed the methodological quality of the trials, and two reviewers independently identified and assessed the non-experimental studies. Data from the trials were pooled using the Exact method to assess vaccine efficacy at 1, 2 and 3 years post- vaccination. The protective effect within the first year was consistent across all 8 trials, vaccine efficacy was 95% (Exact 95% CI 87%, 99%). Protection extended into the second and third year after vaccination, but the results did not attain statistical significance. The only trial that assessed the effect of a booster dose in children less than 18 months old, lacked adequate statistical power. In the three other trials that included children less than 6 years old (one in Sudan and two in Nigeria), none of the vaccinated children developed meningitis, but the results did not attain statistical significance. Data from the two non-experimental studies included in this review were not pooled with the trial data because of methodological limitations. For the first year after vaccination, the vaccine was strongly protective in participants over 5 years of age. It was also protective beyond the first year after vaccination, but the level of vaccine efficacy could not be determined with precision. Children aged 1 to 5 years in developing countries were protected, but the level of efficacy among the youngest children could not be determined. While the vaccine was strongly protective among children aged 3 months and over in developed countries, the number of participants aged under 2 years was too small to draw firm conclusions on the protective effect of, or need for, a booster dose of vaccine.
Hayes, Richard; Ayles, Helen; Beyers, Nulda; Sabapathy, Kalpana; Floyd, Sian; Shanaube, Kwame; Bock, Peter; Griffith, Sam; Moore, Ayana; Watson-Jones, Deborah; Fraser, Christophe; Vermund, Sten H; Fidler, Sarah
2014-02-13
Effective interventions to reduce HIV incidence in sub-Saharan Africa are urgently needed. Mathematical modelling and the HIV Prevention Trials Network (HPTN) 052 trial results suggest that universal HIV testing combined with immediate antiretroviral treatment (ART) should substantially reduce incidence and may eliminate HIV as a public health problem. We describe the rationale and design of a trial to evaluate this hypothesis. A rigorously-designed trial of universal testing and treatment (UTT) interventions is needed because: i) it is unknown whether these interventions can be delivered to scale with adequate uptake; ii) there are many uncertainties in the models such that the population-level impact of these interventions is unknown; and ii) there are potential adverse effects including sexual risk disinhibition, HIV-related stigma, over-burdening of health systems, poor adherence, toxicity, and drug resistance.In the HPTN 071 (PopART) trial, 21 communities in Zambia and South Africa (total population 1.2 m) will be randomly allocated to three arms. Arm A will receive the full PopART combination HIV prevention package including annual home-based HIV testing, promotion of medical male circumcision for HIV-negative men, and offer of immediate ART for those testing HIV-positive; Arm B will receive the full package except that ART initiation will follow current national guidelines; Arm C will receive standard of care. A Population Cohort of 2,500 adults will be randomly selected in each community and followed for 3 years to measure the primary outcome of HIV incidence. Based on model projections, the trial will be well-powered to detect predicted effects on HIV incidence and secondary outcomes. Trial results, combined with modelling and cost data, will provide short-term and long-term estimates of cost-effectiveness of UTT interventions. Importantly, the three-arm design will enable assessment of how much could be achieved by optimal delivery of current policies and the costs and benefits of extending this to UTT. ClinicalTrials.gov NCT01900977.
Pandit, Anil; Aryal, Madan Raj; Aryal Pandit, Aashrayata; Hakim, Fayaz Ahmad; Giri, Smith; Mainali, Naba Raj; Sharma, Prashant; Lee, Howard R; Fortuin, F David; Mookadam, Farouk
2014-01-01
Aim The benefit of preventive percutaneous coronary intervention (PCI) in ST elevation myocardial infarction (STEMI) has been shown in randomised trials. However, all the randomised trials are underpowered to detect benefit in cardiac death. We aim to systematically review evidence on the cardiac mortality benefit of preventive PCI in patients presenting with acute STEMI in randomised patient populations. Methods PubMed, Scopus, Cochrane and clinicaltrials.gov databases were searched for studies published until 30 September 2013. The studies were limited to randomised clinical trials. Independent observers abstracted the data on outcomes, characteristics and qualities of studies included. Fixed effect model was employed for meta-analysis. Heterogeneity of studies included was analysed using I2 statistics. Results In three randomised clinical trials published, involving 748 patients with acute STEMI and multivessel disease, 416 patients were randomised to preventive PCI and 332 to culprit-only PCI. Patients undergoing preventive PCI had significant lower risk of cardiovascular deaths (pooled OR 0.39, 95% CI 0.18 to 0.83, p=0.01, I2=0%), repeat revascularisation (pooled OR 0.28, 95% CI 0.18 to 0.44, p=0.00001, I2=0%) and non-fatal myocardial infarction (pooled OR 0.38, 95% CI 0.20 to 0.75, p=0.005, I2=0%) compared with culprit-only revascularisation. Conclusions In patients presenting with acute STEMI and significant multivessel coronary artery disease, based on our data, preventive PCI is associated with lower risk of cardiovascular mortality compared with primary PCI of only the culprit artery. This finding needs to be confirmed in larger adequately powered randomised clinical trials. PMID:25332779
Kedhi, Elvin; Stone, Gregg W; Kereiakes, Dean J; Serruys, Patrick W; Parise, Helen; Fahy, Martin; Simonton, Charles A; Sudhir, Krishnankutty; Sood, Poornima; Smits, Pieter C
2012-09-01
Recent studies have suggested that EES may reduce ST compared to PES, but no individual trial has been adequately powered for this endpoint. The incidence of stent thrombosis, as well as the impact of dual antiplatelet therapy (DAPT) discontinuation during the first two years following everolimus-eluting stent (EES) and paclitaxel-eluting stent (PES) deployment were therefore analysed from a pooled, patient-level database derived from four randomised clinical trials. Data from the SPIRIT II, SPIRIT III, SPIRIT IV and COMPARE trials (n=6,789 patients) were analysed. Two-year ST rates were determined using time-to-event methods and compared with the log-rank test. ST rates were also determined after DAPT discontinuation. EES compared to PES significantly reduced the two-year rates of ST (0.7% versus 2.3%, p=0.0001), including the interval rates of ST up to 30 days (0.2% versus 1.0%, p<0.0001), between 31 days and one year (0.2% versus 0.6%, p=0.02), and after one year (0.3% versus 0.8%, p=0.001). EES also reduced the two-year composite rate of cardiac death or MI (4.0% versus 6.6%, p=0.0001). Increased rates of ST after DAPT discontinuation beyond six months were observed in the PES cohort, but not in the EES cohort. In this large pooled analysis from four randomised trials, treatment with EES compared to PES significantly reduced the rates of ST through two years of follow-up, with a concomitant reduction in cardiac death or MI. DAPT discontinuation beyond six months may be safe with EES.
Jibb, Lindsay A; Birnie, Kathryn A; Nathan, Paul C; Beran, Tanya N; Hum, Vanessa; Victor, J Charles; Stinson, Jennifer N
2018-06-12
Subcutaneous port needle insertions are painful and distressing for children with cancer. The interactive MEDiPORT robot has been programmed to implement psychological strategies to decrease pain and distress during this procedure. This study assessed the feasibility of a future MEDiPORT trial. The secondary aim was to determine the preliminary effectiveness of MEDiPORT in reducing child pain and distress during subcutaneous port accesses. This 5-month pilot randomized controlled trial used a web-based service to randomize 4- to 9-year-olds with cancer to the MEDiPORT cognitive-behavioral arm (robot using evidence-based cognitive-behavioral interventions) or active distraction arm (robot dancing and singing) while a nurse conducted a needle insertion. We assessed accrual and retention; technical difficulties; outcome measure completion by children, parents, and nurses; time taken to complete the study and clinical procedure; and child-, parent-, and nurse-rated acceptability. Descriptive analyses, with exploratory inferential testing of child pain and distress data, were used to address study aims. Forty children were randomized across study arms. Most (85%) eligible children participated and no children withdrew. Technical difficulties were more common in the cognitive-behavioral arm. Completion times for the study and needle insertion were acceptable and >96% of outcome measure items were completed. Overall, MEDiPORT and the study were acceptable to participants. There was no difference in pain between arms, but distress during the procedure was less pronounced in the active distraction arm. The MEDiPORT study appears feasible to implement as an adequately-powered effectiveness-assessing trial following modifications to the intervention and study protocol. ClinicalTrials.gov NCT02611739. © 2018 Wiley Periodicals, Inc.
Boersma, Doeke; van Eekeren, Ramon R J P; Kelder, Hans J C; Werson, Debora A B; Holewijn, Suzanne; Schreve, Michiel A; Reijnen, Michel M P J; de Vries, Jean Paul P M
2014-10-29
Minimally invasive endothermal techniques, for example, radiofrequency ablation (RFA), have revolutionized the treatment of insufficient truncal veins and are associated with an excellent outcome. The use of thermal energy requires the instillation of tumescent anesthesia around the vein. Mechanochemical endovenous ablation (MOCA™) combines mechanical endothelial damage, using a rotating wire, with simultaneous infusion of a liquid sclerosans. Tumescent anesthesia is not required as no heat is used. Prospective studies using MOCA™ in both great and small saphenous veins showed good anatomical and clinical results with fast postoperative recovery. The MESSI trial (Mechanochemical Endovenous ablation versus radiofrequency ablation in the treatment of primary Small Saphenous vein Insufficiency) is a multicenter randomized controlled trial in which a total of 160 patients will be randomized (1:1) to MOCA™ or RFA. Consecutive patients with primary small saphenous vein incompetence, who meet the eligibility criteria, will be invited to participate in this trial. The primary endpoint is anatomic success, defined as occlusion of the treated veins objectified with duplex ultrasonography at 1 year follow-up. Secondary endpoints are post-procedural pain, initial technical success, clinical success, complications and the duration of the procedure. Initial technical success is defined as the ability to position the device adequately, treat the veins as planned and occlude the treated vein directly after the procedure has been proven by duplex ultrasonography. Clinical success is defined as an objective improvement of clinical outcome after treatment, measured with the Venous Clinical Severity Score (VCSS). Power analyses are conducted for anatomical success and post-procedural pain.Both groups will be evaluated on an intention-to-treat principle. The hypothesis of the MESSI trial is that the anatomic success rate of MOCA™ is not inferior to RFA. The second hypothesis is that post-procedural pain is significantly less after MOCA compared to RFA. NTR4613 Date of trial registration: 28 May 2014.
Patel, Hitesh C; Hayward, Carl; Dungu, Jason N; Papadopoulou, Sofia; Saidmeerasah, Abdel; Ray, Robin; Di Mario, Carlo; Shanmugam, Nesan; Cowie, Martin R; Anderson, Lisa J
2017-07-01
To investigate the effect of the different eligibility criteria used by phase III clinical studies in heart failure with preserved ejection fraction (HFpEF) on patient selection, phenotype, and survival. We applied the key eligibility criteria of 7 phase III HFpEF studies (Digitalis Investigation Group Ancillary, Candesartan in Patients With Chronic Heart Failure and Preserved Left-Ventricular Ejection Fraction, Perindopril in Elderly People With Chronic Heart Failure, Irbesartan in Heart Failure With Preserved Systolic Function, Japanese Diastolic Heart Failure, Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist, and Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction [PARAGON-HF; ongoing]) to a typical and well-characterized HFpEF population (n = 557) seen in modern European cardiological practice. Follow-up was available for a minimum of 24 months in each patient. Increasing the number of study eligibility criteria identifies a progressively smaller group of patients from real-life practice suitable for recruitment into clinical trials; using the J-DHF criteria, 81% of our clinic patients would have been eligible, whereas the PARAGON-HF criteria significantly reduced this proportion to 32%. The patients identified from our clinical population had similar mortality rates using the different criteria, which were consistently higher than those reported in the actual clinic trials. Trial eligibility criteria have become stricter with time, which reduces the number of eligible patients, affecting both generalizability of any findings and feasibility of completing an adequately powered trial. We could not find evidence that the additional criteria used in more recent randomized trials in HFpEF have identified patients at higher risk of all-cause mortality. Copyright © 2017 Elsevier Inc. All rights reserved.
Johnson, Miriam J; Booth, Sara; Currow, David C; Lam, Lawrence T; Phillips, Jane L
2016-05-01
The handheld fan is an inexpensive and safe way to provide facial airflow, which may reduce the sensation of chronic refractory breathlessness, a frequently encountered symptom. To test the feasibility of developing an adequately powered, multicenter, multinational randomized controlled trial comparing the efficacy of a handheld fan and exercise advice with advice alone in increasing activity in people with chronic refractory breathlessness from a variety of medical conditions, measuring recruitment rates; data quality; and potential primary outcome measures. This was a Phase II, multisite, international, parallel, nonblinded, mixed-methods randomized controlled trial. Participants were centrally randomized to fan or control. All received breathlessness self-management/exercise advice and were followed up weekly for four weeks. Participants/carers were invited to participate in a semistructured interview at the study's conclusion. Ninety-seven people were screened, 49 randomized (mean age 68 years; 49% men), and 43 completed the study. Site recruitment varied from 0.25 to 3.3/month and screening:randomization from 1.1:1 to 8.5:1. There were few missing data except for the Chronic Obstructive Pulmonary Disease Self-Efficacy Scale (two-thirds of data missing). No harms were observed. Three interview themes included 1) a fan is a helpful self-management strategy, 2) a fan aids recovery, and 3) a symptom control trial was welcome. A definitive, multisite trial to study the use of the handheld fan as part of self-management of chronic refractory breathlessness is feasible. Participants found the fan useful. However, the value of information for changing practice or policy is unlikely to justify the expense of such a trial, given perceived benefits, the minimal costs, and an absence of harms demonstrated in this study. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Storkel, Holly L.; Voelmle, Krista; Fierro, Veronica; Flake, Kelsey; Fleming, Kandace K.; Romine, Rebecca Swinburne
2017-01-01
Purpose: This study sought to identify an adequate intensity of interactive book reading for new word learning by children with specific language impairment (SLI) and to examine variability in treatment response. Method: An escalation design adapted from nontoxic drug trials (Hunsberger, Rubinstein, Dancey, & Korn, 2005) was used in this Phase…
Thomson, Denise; Hartling, Lisa; Cohen, Eyal; Vandermeer, Ben; Tjosvold, Lisa; Klassen, Terry P
2010-09-30
The objective of this study was to describe randomized controlled trials (RCTs) and controlled clinical trials (CCTs) in child health published between 1948 and 2006, in terms of quantity, methodological quality, and publication and trial characteristics. We used the Trials Register of the Cochrane Child Health Field for overall trends and a sample from this to explore trial characteristics in more detail. We extracted descriptive data on a random sample of 578 trials. Ninety-six percent of the trials were published in English; the percentage of child-only trials was 90.5%. The most frequent diagnostic categories were infectious diseases (13.2%), behavioural and psychiatric disorders (11.6%), neonatal critical care (11.4%), respiratory disorders (8.9%), non-critical neonatology (7.9%), and anaesthesia (6.5%). There were significantly fewer child-only studies (i.e., more mixed child and adult studies) over time (P = 0.0460). The proportion of RCTs to CCTs increased significantly over time (P<0.0001), as did the proportion of multicentre trials (P = 0.002). Significant increases over time were found in methodological quality (Jadad score) (P<0.0001), the proportion of double-blind studies (P<0.0001), and studies with adequate allocation concealment (P<0.0001). Additionally, we found an improvement in reporting over time: adequate description of withdrawals and losses to follow-up (P<0.0001), sample size calculations (P<0.0001), and intention-to-treat analysis (P<0.0001). However, many trials still do not describe their level of blinding, and allocation concealment was inadequately reported in the majority of studies across the entire time period. The proportion of studies with industry funding decreased slightly over time (P = 0.003), and these studies were more likely to report positive conclusions (P = 0.028). The quantity and quality of pediatric controlled trials has increased over time; however, much work remains to be done, particularly in improving methodological issues around conduct and reporting of trials.
Research gaps identified during systematic reviews of clinical trials: glass-ionomer cements.
Mickenautsch, Steffen
2012-06-29
To report the results of an audit concerning research gaps in clinical trials that were accepted for appraisal in authored and published systematic reviews regarding the application of glass-ionomer cements (GIC) in dental practice Information concerning research gaps in trial precision was extracted, following a framework that included classification of the research gap reasons: 'imprecision of information (results)', 'biased information', 'inconsistency or unknown consistency' and 'not the right information', as well as research gap characterization using PICOS elements: population (P), intervention (I), comparison (C), outcomes (O) and setting (S). Internal trial validity assessment was based on the understanding that successful control for systematic error cannot be assured on the basis of inclusion of adequate methods alone, but also requires empirical evidence about whether such attempt was successful. A comprehensive and interconnected coverage of GIC-related clinical topics was established. The most common reasons found for gaps in trial precision were lack of sufficient trials and lack of sufficient large sample size. Only a few research gaps were ascribed to 'Lack of information' caused by focus on mainly surrogate trial outcomes. According to the chosen assessment criteria, a lack of adequate randomisation, allocation concealment and blinding/masking in trials covering all reviewed GIC topics was noted (selection- and detection/performance bias risk). Trial results appear to be less affected by loss-to-follow-up (attrition bias risk). This audit represents an adjunct of the systematic review articles it has covered. Its results do not change the systematic review's conclusions but highlight existing research gaps concerning the precision and internal validity of reviewed trials in detail. These gaps should be addressed in future GIC-related clinical research.
Microbiota and prebiotics modulation of uremic toxin generation.
Koppe, Laetitia; Fouque, Denis
2017-06-01
Recent data have shown that the host-intestinal microbiota interaction is intrinsically linked with overall health. Chronic kidney disease (CKD) could influence intestinal microbiota and gut dysbiosis is also considered as a cause of progression of kidney disease. An increasing body of evidence indicates that dysbiosis is a key contributor of uremic retention solutes (URS) accumulating in patients with CKD. The discovery of the kidney-gut axis has created new therapeutic opportunities for nutritional intervention in order to prevent adverse outcomes. One of these strategies is prebiotics, which refers to nondigestible food ingredients or substances that beneficial affect growth and/or activity of limited health-promoting bacteria in the gastrointestinal tract. The influence of prebiotics on the production and concentration of URS have been investigated in various animal and human CKD studies. However, to date, there is still paucity of high-quality intervention trials. Randomized controlled trials and adequately powered intervention studies are needed before recommending prebiotics in clinical practice. This review will outline the interconnection between CKD progression, dysbiosis and URS production and will discuss mechanisms of action and efficacy of prebiotics as a new CKD management tool, with a particular emphasis on URS generation.
Vitamin D and the Development of Atopic Eczema
Palmer, Debra J.
2015-01-01
A “vitamin D hypothesis” has been proposed to explain the increased prevalence of eczema in regions with higher latitude. This review focuses on the current available evidence with regard to the possible effect of vitamin D on the development of atopic eczema. Observational studies have indicated a link between vitamin D status and eczema outcomes, including lower serum vitamin D levels associated with increased incidence and severity of eczema symptoms. Vitamin D is known to have a regulatory influence on both the immune system and skin barrier function, both critical in the pathogenesis of eczema. However heterogeneous results have been found in studies to date investigating the effect of vitamin D status during pregnancy and infancy on the prevention of eczema outcomes. Well-designed, adequately powered, randomised controlled trials are needed. The study design of any new intervention trials should measure vitamin D levels at multiple time points during the intervention, ultraviolet (UV) radiation exposure via the use of individual UV dosimeters, and investigate the role of individual genetic polymorphisms. In conclusion, the current available evidence does not allow firm conclusions to be made on whether vitamin D status affects the development of atopic eczema. PMID:26239464
Exercise Training in Treatment and Rehabilitation of Hip Osteoarthritis: A 12-Week Pilot Trial
Patil, Radhika; Karinkanta, Saija; Tokola, Kari; Kannus, Pekka
2017-01-01
Introduction. Osteoarthritis (OA) of the hip is one of the major causes of pain and disability in the older population. Although exercise is an effective treatment for knee OA, there is lack of evidence regarding hip OA. The aim of this trial was to test the safety and feasibility of a specifically designed exercise program in relieving hip pain and improving function in hip OA participants and to evaluate various methods to measure changes in their physical functioning. Materials and Methods. 13 women aged ≥ 65 years with hip OA were recruited in this 12-week pilot study. Results. Pain declined significantly over 30% from baseline, and joint function and health-related quality of life improved slightly. Objective assessment of physical functioning showed statistically significant improvement in the maximal isometric leg extensor strength by 20% and in the hip extension range of motion by 30%. Conclusions. The exercise program was found to be safe and feasible. The present evidence indicates that the exercise program is effective in the short term. However, adequate powered RCTs are needed to determine effects of long-term exercise therapy on pain and progression of hip OA. PMID:28116214
Do implant overdentures improve dietary intake? A randomized clinical trial.
Hamdan, N M; Gray-Donald, K; Awad, M A; Johnson-Down, L; Wollin, S; Feine, J S
2013-12-01
People wearing mandibular two-implant overdentures (IOD) chew food with less difficulty than those wearing conventional complete dentures (CD). However, there is still controversy over whether or not this results in better dietary intake. In this randomized clinical trials (RCT), the amounts of total dietary fiber (TDF), macronutrients, 9 micronutrients, and energy in diets consumed by persons with IOD and CD were compared. Male and female edentate patients ≥ 65 yrs (n = 255) were randomly divided into 2 groups and assigned to receive a maxillary CD and either a mandibular IOD or a CD. One year following prosthesis delivery, 217 participants (CD = 114, IOD = 103) reported the food and quantities they consumed to a registered dietician through a standard 24-hour dietary recall method. The mean and median values of TDF, macro- and micronutrients, and energy consumed by both groups were calculated and compared analytically. No significant between-group differences were found (ps > .05). Despite quality-of-life benefits from IODs, this adequately powered study reveals no evidence of nutritional advantages for independently living medically healthy edentate elders wearing two-implant mandibular overdentures over those wearing conventional complete dentures in their dietary intake at one year following prosthesis delivery.
Ekeland, E; Heian, F; Hagen, K B
2005-11-01
A systematic review to determine if exercise alone or as part of a comprehensive intervention can improve self esteem in children and young people is described. Twenty three randomised controlled trials were analysed. A synthesis of several small, low quality trials indicates that exercise may have short term beneficial effects on self esteem in children and adolescents. However, high quality research on defined populations with adequate follow up is needed.
Treatment algorithms and protocolized care.
Morris, Alan H
2003-06-01
Excess information in complex ICU environments exceeds human decision-making limits and likely contributes to unnecessary variation in clinical care, increasing the likelihood of clinical errors. I reviewed recent critical care clinical trials searching for information about the impact of protocol use on clinically pertinent outcomes. Several recently published clinical trials illustrate the importance of distinguishing efficacy and effectiveness trials. One of these trials illustrates the danger of conducting effectiveness trials before the efficacy of an intervention is established. The trials also illustrate the importance of distinguishing guidelines and inadequately explicit protocols from adequately explicit protocols. Only adequately explicit protocols contain enough detail to lead different clinicians to the same decision when faced with the same clinical scenario. Differences between guidelines and protocols are important. Guidelines lack detail and provide general guidance that requires clinicians to fill in many gaps. Computerized or paper-based protocols are detailed and, when used for complex clinical ICU problems, can generate patient-specific, evidence-based therapy instructions that can be carried out by different clinicians with almost no interclinician variability. Individualization of patient therapy can be preserved by these protocols when they are driven by individual patient data. Explicit decision-support tools (eg, guidelines and protocols) have favorable effects on clinician and patient outcomes and can reduce the variation in clinical practice. Guidelines and protocols that aid ICU decision makers should be more widely distributed.
Recent direct seeding trials in the pine region
H.A. Fowells; G.H. Schubert
1951-01-01
Direct seeding is a highly desirable method of regeneration. It is more economical and more flexible in both time and place than the planting of trees. In California, however, direct seeding generally has been an ineffective method of regeneration. Early trials by the Forest Service with broadcast sowing and spot sowing invariably failed to produce an adequate stand of...
Effect of body condition on consumption of pine needles (Pinus ponderosa) by beef cows
USDA-ARS?s Scientific Manuscript database
We determined if cattle in low (LBC) or high body condition (HBC) would consume different amounts of green pine needles (Pinus ponderosa). Cattle (mature; open Hereford and Hereford x Angus) were fed an adequate basal diet (alfalfa pellets) for Trials 1 and 2; during Trials 3 and 4 cows were fed hig...
Antibacterial agents in composite restorations for the prevention of dental caries.
Pereira-Cenci, Tatiana; Cenci, Maximiliano S; Fedorowicz, Zbys; Azevedo, Marina
2013-12-17
Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria from the biofilm (dental plaque) leads to localised demineralisation of tooth surfaces, which may ultimately result in cavity formation. Resin composites are widely used in dentistry to restore teeth. These restorations can fail for a number of reasons, such as secondary caries, and restorative material fracture and other minor reasons. From these, secondary caries, which are caries lesions developed adjacent to restorations, is the main cause for restorations replacement. The presence of antibacterials in both the filling material and the bonding systems would theoretically be able to affect the initiation and progression of caries adjacent to restorations. This is an update of the Cochrane review published in 2009. To assess the effects of antibacterial agents incorporated into composite restorations for the prevention of dental caries. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 23 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6), MEDLINE via OVID (1946 to 23 July 2013) and EMBASE via OVID (1980 to 23 July 2013). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov), the metaRegister of Controlled Trials (www.controlled-trials.com) and the World Health Organization International Clinical Trials Registry platform (www.who.int/trialsearch) for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials comparing resin composite restorations containing antibacterial agents with composite restorations not containing antibacterial agents. Two review authors conducted screening of studies in duplicate and independently, and although no eligible trials were identified, the two authors had planned to extract data independently and assess trial quality using standard Cochrane Collaboration methodologies. We retrieved 308 references to studies, none of which matched the inclusion criteria for this review and all of which were excluded. We were unable to identify any randomised controlled trials on the effects of antibacterial agents incorporated into composite restorations for the prevention of dental caries. The absence of high level evidence for the effectiveness of this intervention emphasises the need for well designed, adequately powered, randomised controlled clinical trials. Thus, conclusions remain the same as the previously published review, with no included clinical trials.
Dynamic adjustments of cognitive control: oscillatory correlates of the conflict adaptation effect.
Pastötter, Bernhard; Dreisbach, Gesine; Bäuml, Karl-Heinz T
2013-12-01
It is a prominent idea that cognitive control mediates conflict adaptation, in that response conflict in a previous trial triggers control adjustments that reduce conflict in a current trial. In the present EEG study, we investigated the dynamics of cognitive control in a response-priming task by examining the effects of previous trial conflict on intertrial and current trial oscillatory brain activities, both on the electrode and the source level. Behavioral results showed conflict adaptation effects for RTs and response accuracy. Physiological results showed sustained intertrial effects in left parietal theta power, originating in the left inferior parietal cortex, and midcentral beta power, originating in the left and right (pre)motor cortex. Moreover, physiological analysis revealed a current trial conflict adaptation effect in midfrontal theta power, originating in the ACC. Correlational analyses showed that intertrial effects predicted conflict-induced midfrontal theta power in currently incongruent trials. In addition, conflict adaptation effects in midfrontal theta power and RTs were positively related. Together, these findings point to a dynamic cognitive control system that, as a function of previous trial type, up- and down-regulates attention and preparatory motor activities in anticipation of the next trial.
Straker, Leon M; Campbell, Amity C; Jensen, Lyn M; Metcalf, Deborah R; Smith, Anne J; Abbott, Rebecca A; Pollock, Clare M; Piek, Jan P
2011-08-18
A healthy start to life requires adequate motor development and physical activity participation. Currently 5-15% of children have impaired motor development without any obvious disorder. These children are at greater risk of obesity, musculoskeletal disorders, low social confidence and poor mental health. Traditional electronic game use may impact on motor development and physical activity creating a vicious cycle. However new virtual reality (VR) game interfaces may provide motor experiences that enhance motor development and lead to an increase in motor coordination and better physical activity and mental health outcomes. VR games are beginning to be used for rehabilitation, however there is no reported trial of the impact of these games on motor coordination in children with developmental coordination disorder. This cross-over randomised and controlled trial will examine whether motor coordination is enhanced by access to active electronic games and whether daily activity, attitudes to physical activity and mental health are also enhanced. Thirty children aged 10-12 years with poor motor coordination (≤ 15th percentile) will be recruited and randomised to a balanced ordering of 'no active electronic games' and 'active electronic games'. Each child will participate in both conditions for 16 weeks, and be assessed prior to participation and at the end of each condition. The primary outcome is motor coordination, assessed by kinematic and kinetic motion analysis laboratory measures. Physical activity and sedentary behaviour will be assessed by accelerometry, coordination in daily life by parent report questionnaire and attitudes to physical activity, self-confidence, anxiety and depressed mood will be assessed by self report questionnaire. A sample of 30 will provide a power of > 0.9 for detecting a 5 point difference in motor coordination on the MABC-2 TIS scale (mean 17, sd = 5). This is the first trial to examine the impact of new virtual reality games on motor coordination in children with developmental coordination disorder. The findings will provide critical information to understand whether these electronic games can be used to have a positive impact on the physical and mental health of these children. Given the importance of adequate motor coordination, physical activity and mental health in childhood, this project can inform interventions which could have a profound impact on the long term health of this group of children. Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000400965.
Update on Vitamin E and Its Potential Role in Preventing or Treating Bronchopulmonary Dysplasia.
Stone, Cosby A; McEvoy, Cindy T; Aschner, Judy L; Kirk, Ashudee; Rosas-Salazar, Christian; Cook-Mills, Joan M; Moore, Paul E; Walsh, William F; Hartert, Tina V
2018-03-07
Vitamin E is obtained only through the diet and has a number of important biological activities, including functioning as an antioxidant. Evidence that free radicals may contribute to pathological processes such as bronchopulmonary dysplasia (BPD), a disease of prematurity associated with increased lung injury, inflammation and oxidative stress, led to trials of the antioxidant vitamin E (α-tocopherol) to prevent BPD with variable results. These trials were all conducted at supraphysiologic doses and 2 of these trials utilized a formulation containing a potentially harmful excipient. Since 1991, when the last of these trials was conducted, both neonatal management strategies for minimizing oxygen and ventilator-related lung injury and our understanding of vitamin E isoforms in respiratory health have advanced substantially. It is now known that there are differences between the effects of vitamin E isoforms α-tocopherol and γ-tocopherol on the development of respiratory morbidity and inflammation. What is not known is whether improvements in physiologic concentrations of individual or combinations of vitamin E isoforms during pregnancy or following preterm birth might prevent or reduce BPD development. The answers to these questions require adequately powered studies targeting pregnant women at risk of preterm birth or their premature infants immediately following birth, especially in certain subgroups that are at increased risk of vitamin E deficiency (e.g., smokers). The objective of this review is to compile, update, and interpret what is known about vitamin E isoforms and BPD since these first studies were conducted, and suggest future research directions. © 2018 S. Karger AG, Basel.
Parry, Steve W; Deary, Vincent; Finch, Tracy; Bamford, Claire; Sabin, Neil; McMeekin, Peter; O'Brien, John; Caldwell, Alma; Steen, Nick; Whitney, Susan L; Macdonald, Claire; McColl, Elaine
2014-06-06
Around 30% to 62% of older individuals fall each year, with adverse consequences of falls being by no means limited to physical injury and escalating levels of dependence. Many older individuals suffer from a variety of adverse psychosocial difficulties related to falling including fear, anxiety, loss of confidence and subsequent increasing activity avoidance, social isolation and frailty. Such 'fear of falling' is common and disabling, but definitive studies examining the effective management of the syndrome are lacking. Cognitive behavioural therapy has been trialed with some success in a group setting, but there is no adequately powered randomised controlled study of an individually based cognitive behavioural therapy intervention, and none using non-mental health professionals to deliver the intervention. We are conducting a two-phase study examining the role of individual cognitive behavioural therapy delivered by healthcare assistants in improving fear of falling in older adults. In Phase I, the intervention was developed and taught to healthcare assistants, while Phase II is the pragmatic randomised controlled study examining the efficacy of the intervention in improving fear of falling in community-dwelling elders attending falls services. A qualitative process evaluation study informed by Normalization Process Theory is being conducted throughout to examine the potential promoters and inhibitors of introducing such an intervention into routine clinical practice, while a health economic sub-study running alongside the trial is examining the costs and benefits of such an approach to the wider health economy. Current Controlled Trials ISRCTN78396615.
Hughes, Sheryl O; Power, Thomas G; Beck, Ashley; Betz, Drew; Calodich, Shirley; Goodell, L Suzanne; Hill, Laura G; Hill, Rachael; Jaramillo, J Andrea; Johnson, Susan L; Lanigan, Jane; Lawrence, Adair; Martinez, AnaMaria Diaz; Nesbitt, Merrianneeta; Overath, Irene; Parker, Louise; Ullrich-French, Sarah
2016-06-01
To develop a scientifically based childhood obesity prevention program supporting child eating self-regulation and taste preferences. This article describes the research methods for the Strategies for Effective Eating Development program. A logic model is provided that depicts a visual presentation of the activities that will be used to guide the development of the prevention program. Randomized, controlled prevention program, pretest, posttest, 6 months, and 12 months. Two sites: Houston, TX and Pasco, WA. Each trial will last 7 weeks with 8-10 mother-child dyads in each arm (prevention and control). Recruitment at Head Start districts (Texas; n = 160) and Inspire Child Development Center including Early Childhood Education and Head Start (Washington; n = 160). Sixteen trials with 16-20 parent-child dyads per trial will provide adequate power to detect moderate effects. Multicomponent family-based prevention program incorporating a dialogue approach to adult learning and self-determination theory. Child assessments will include observed taste preferences, caloric compensation, and eating in the absence of hunger. Parent assessments will include parent-reported feeding, feeding emotions, acculturation, child eating behaviors, child food preferences, and child dietary intake. Heights and weights will be measured for parent and child. A multilevel growth modeling analysis will be employed to consider the nested nature of the data: time points (level 1) within families (level 2) within trials (level 3). Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.
Koethe, John R; Westfall, Andrew O; Luhanga, Dora K; Clark, Gina M; Goldman, Jason D; Mulenga, Priscilla L; Cantrell, Ronald A; Chi, Benjamin H; Zulu, Isaac; Saag, Michael S; Stringer, Jeffrey S A
2010-03-12
The benefit of routine HIV-1 viral load (VL) monitoring of patients on antiretroviral therapy (ART) in resource-constrained settings is uncertain because of the high costs associated with the test and the limited treatment options. We designed a cluster randomized controlled trial to compare the use of routine VL testing at ART-initiation and at 3, 6, 12, and 18 months, versus our local standard of care (which uses immunological and clinical criteria to diagnose treatment failure, with discretionary VL testing when the two do not agree). Dedicated study personnel were integrated into public-sector ART clinics. We collected participant information in a dedicated research database. Twelve ART clinics in Lusaka, Zambia constituted the units of randomization. Study clinics were stratified into pairs according to matching criteria (historical mortality rate, size, and duration of operation) to limit the effect of clustering, and independently randomized to the intervention and control arms. The study was powered to detect a 36% reduction in mortality at 18 months. From December 2006 to May 2008, we completed enrollment of 1973 participants. Measured baseline characteristics did not differ significantly between the study arms. Enrollment was staggered by clinic pair and truncated at two matched sites. A large clinical trial of routing VL monitoring was successfully implemented in a dynamic and rapidly growing national ART program. Close collaboration with local health authorities and adequate reserve staff were critical to success. Randomized controlled trials such as this will likely prove valuable in determining long-term outcomes in resource-constrained settings. Clinicaltrials.gov NCT00929604.
Greene, Stephen J.; Shah, Ami N.; Butler, Javed; Ambrosy, Andrew P.; Anker, Stefan D.; Chioncel, Ovidiu; Collins, Sean P.; Dinh, Wilfried; Dunnmon, Preston M.; Fonarow, Gregg C.; Lam, Carolyn S. P.; Mentz, Robert J.; Pieske, Burkert; Roessig, Lothar; Rosano, Giuseppe M. C.; Sato, Naoki; Vaduganathan, Muthiah; Gheorghiade, Mihai
2014-01-01
Recent international phase III clinical trials of novel therapies for hospitalized heart failure (HHF) have failed to improve the unacceptably high postdischarge event rate. These large studies have demonstrated notable geographic and site-specific variation in patient profiles and enrollment. Possible contributors to the lack of success in HHF outcome trials include challenges in selecting clinical sites capable of (1) providing adequate numbers of appropriately selected patients and (2) properly executing the study protocol. We propose a “pretrial registry” as a novel tool for improving the efficiency and quality of international HHF trials by focusing on the selection and cultivation of high-quality sites. A pretrial registry may help assess a site’s ability to achieve adequate enrollment of the target patient population, integrate protocol requirements into clinical workflow, and accomplish appropriate follow-up. Although such a process would be associated with additional upfront resource investment, this appropriation may be modest in comparison with the downstream costs associated with maintenance of poorly performing sites, failed clinical trials, and the global health and economic burden of HHF. This review is based on discussions between scientists, clinical trialists, and regulatory representatives regarding methods for improving international HHF trials that took place at the United States Food and Drug Administration on January 12th, 2012. PMID:25066552
To, Matthew J; Jones, Jennifer; Emara, Mohamed; Jadad, Alejandro R
2013-01-01
Inadequate reporting undermines findings of randomized controlled trials (RCTs). This study assessed and compared articles published in high-impact general medical and specialized journals. Reports of RCTs published in high-impact general and specialized medical journals were identified through a search of MEDLINE from January to March of 1995, 2000, 2005, and 2010. Articles that provided original data on adult patients diagnosed with chronic conditions were included in the study. Data on trial characteristics, reporting of allocation concealment, quality score, and the presence of a trial flow diagram were extracted independently by two reviewers, and discrepancies were resolved by consensus or independent adjudication. Descriptive statistics were used for quantitative variables. Comparisons between general medical and specialized journals, and trends over time were performed using Chi-square tests. Reports of 284 trials were analyzed. There was a significantly higher proportion of RCTs published with adequate reporting of allocation concealment (p = 0.003), presentation of a trial flow diagram (p<0.0001) and high quality scores (p = 0.038) over time. Trials published in general medical journals had higher quality scores than those in specialized journals (p = 0.001), reported adequate allocation concealment more often (p = 0.013), and presented a trial flow diagram more often (p<0.001). We found significant improvements in reporting quality of RCTs published in high-impact factor journals over the last fifteen years. These improvements are likely attributed to concerted international efforts to improve reporting quality such as CONSORT. There is still much room for improvement, especially among specialized journals.
GOST: A generic ordinal sequential trial design for a treatment trial in an emerging pandemic.
Whitehead, John; Horby, Peter
2017-03-01
Conducting clinical trials to assess experimental treatments for potentially pandemic infectious diseases is challenging. Since many outbreaks of infectious diseases last only six to eight weeks, there is a need for trial designs that can be implemented rapidly in the face of uncertainty. Outbreaks are sudden and unpredictable and so it is essential that as much planning as possible takes place in advance. Statistical aspects of such trial designs should be evaluated and discussed in readiness for implementation. This paper proposes a generic ordinal sequential trial design (GOST) for a randomised clinical trial comparing an experimental treatment for an emerging infectious disease with standard care. The design is intended as an off-the-shelf, ready-to-use robust and flexible option. The primary endpoint is a categorisation of patient outcome according to an ordinal scale. A sequential approach is adopted, stopping as soon as it is clear that the experimental treatment has an advantage or that sufficient advantage is unlikely to be detected. The properties of the design are evaluated using large-sample theory and verified for moderate sized samples using simulation. The trial is powered to detect a generic clinically relevant difference: namely an odds ratio of 2 for better rather than worse outcomes. Total sample sizes (across both treatments) of between 150 and 300 patients prove to be adequate in many cases, but the precise value depends on both the magnitude of the treatment advantage and the nature of the ordinal scale. An advantage of the approach is that any erroneous assumptions made at the design stage about the proportion of patients falling into each outcome category have little effect on the error probabilities of the study, although they can lead to inaccurate forecasts of sample size. It is important and feasible to pre-determine many of the statistical aspects of an efficient trial design in advance of a disease outbreak. The design can then be tailored to the specific disease under study once its nature is better understood.
The effect of extrinsic motivation on cycle time trial performance.
Hulleman, Michiel; De Koning, Jos J; Hettinga, Florentina J; Foster, Carl
2007-04-01
Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. Well-trained recreational cyclists (N=7) completed four 1500-m laboratory time trials including a practice trial, two self-paced trials, and a trial where a monetary reward was offered. Time, total power output, power output attributable to aerobic and anaerobic metabolic sources, VO2, and HR were measured. The time required for the second, third, and last (extrinsically motivated) time trials was 133.1 +/- 2.1, 134.1 +/- 3.4, and 133.6 +/- 3.0 s, respectively, and was not different (P>0.05). There were no differences for total (396 +/- 19, 397 +/- 23, and 401 +/- 17 W), aerobic (253 +/- 12, 254 +/- 10, and 246 +/- 13 W), and anaerobic (143 +/- 14, 143 +/- 21, and 155 +/- 11 W) power output. The highest VO2 was not different over consecutive time trials (3.76 +/- 0.19, 3.73 +/- 0.16, and 3.71 +/- 0.22 L x min(-1)). When ranked by performance, without reference to the extrinsic motivation (131.9 +/- 2.4, 133.4 +/- 2.4, and 135.4 +/- 2.5 s), there was a significant difference for the first 100 m and from 100 to 300 m in power output, with a larger total power (560 +/- 102, 491 +/- 82, and 493 +/- 93; and 571 +/- 94, 513 +/- 41, and 484 +/- 88 W) and power attributable to anaerobic sources (446 +/- 100, 384 +/- 80, and 324 +/- 43; and 381 +/- 87, 383 +/- 90, and 289 +/- 91 W) for the fastest trial. Extrinsic motivation did not change the time trial performance, suggesting that 1500-m performance is extremely stable and not readily changeable with simple external motivation. The results suggest that spontaneous improvement in performance for time trials of this duration is attributable to greater early power output, which is primarily attributable to anaerobic metabolic sources.
A generalized concept of power helped to choose optimal endpoints in clinical trials.
Borm, George F; van der Wilt, Gert J; Kremer, Jan A M; Zielhuis, Gerhard A
2007-04-01
A clinical trial may have multiple objectives. Sometimes the results for several parameters may need to be significant or meet certain other criteria. In such cases, it is important to evaluate the probability that all these objectives will be met, rather than the probability that each will be met. The purpose of this article is to introduce a definition of power that is tailored to handle this situation and that is helpful for the design of such trials. We introduce a generalized concept of power. It can handle complex situations, for example, in which there is a logical combination of partial objectives. These may be formulated not only in terms of statistical tests and of confidence intervals, but also in nonstatistical terms, such as "selecting the optimal by dose." The power of a trial was calculated for various objectives and combinations of objectives. The generalized concept of power may lead to power calculations that closely match the objectives of the trial and contribute to choosing more efficient endpoints and designs.
Storkel, Holly L; Voelmle, Krista; Fierro, Veronica; Flake, Kelsey; Fleming, Kandace K; Romine, Rebecca Swinburne
2017-01-01
This study sought to identify an adequate intensity of interactive book reading for new word learning by children with specific language impairment (SLI) and to examine variability in treatment response. An escalation design adapted from nontoxic drug trials (Hunsberger, Rubinstein, Dancey, & Korn, 2005) was used in this Phase I/II preliminary clinical trial. A total of 27 kindergarten children with SLI were randomized to 1 of 4 intensities of interactive book reading: 12, 24, 36, or 48 exposures. Word learning was monitored through a definition task and a naming task. An intensity response curve was examined to identify the adequate intensity. Correlations and classification accuracy were used to examine variation in response to treatment relative to pretreatment and early treatment measures. Response to treatment improved as intensity increased from 12 to 24 to 36 exposures, and then no further improvements were observed as intensity increased to 48 exposures. There was variability in treatment response: Children with poor phonological awareness, low vocabulary, and/or poor nonword repetition were less likely to respond to treatment. The adequate intensity for this version of interactive book reading was 36 exposures, but further development of the treatment is needed to increase the benefit for children with SLI.
Voelmle, Krista; Fierro, Veronica; Flake, Kelsey; Fleming, Kandace K.; Romine, Rebecca Swinburne
2017-01-01
Purpose This study sought to identify an adequate intensity of interactive book reading for new word learning by children with specific language impairment (SLI) and to examine variability in treatment response. Method An escalation design adapted from nontoxic drug trials (Hunsberger, Rubinstein, Dancey, & Korn, 2005) was used in this Phase I/II preliminary clinical trial. A total of 27 kindergarten children with SLI were randomized to 1 of 4 intensities of interactive book reading: 12, 24, 36, or 48 exposures. Word learning was monitored through a definition task and a naming task. An intensity response curve was examined to identify the adequate intensity. Correlations and classification accuracy were used to examine variation in response to treatment relative to pretreatment and early treatment measures. Results Response to treatment improved as intensity increased from 12 to 24 to 36 exposures, and then no further improvements were observed as intensity increased to 48 exposures. There was variability in treatment response: Children with poor phonological awareness, low vocabulary, and/or poor nonword repetition were less likely to respond to treatment. Conclusion The adequate intensity for this version of interactive book reading was 36 exposures, but further development of the treatment is needed to increase the benefit for children with SLI. PMID:28036410
Corbett, Mark S; Watson, Judith; Eastwood, Alison
2016-10-19
We recently published a systematic review of different healthcare settings (such as outpatient, community or home) for administering intravenous chemotherapy, and concluded that performing conventionally designed randomised trials was difficult. The main problems were achieving adequate trial accrual rates and recruiting a study population which adequately represented the target population of interest. These issues stemmed from the fact that potential participants may have had pre-trial perceptions about the trial settings they may be allocated; such preferences will sometimes be strong enough for patients to decline an invitation to participate in a trial. A patient preference trial design (in which patients can choose, or be randomised to, an intervention) may have obviated these recruitment issues, although none of the trials used such a design. In order to gain a better understanding of the broader prevalence and extent of these preference issues (and any other methodological challenges), we undertook an exploratory review of settings trials in any area of healthcare treatment research. We searched The Cochrane Library and Google Scholar and used snowballing methods to identify trials comparing different healthcare settings. Trial accrual was affected by patient preferences for a setting in 15 of the 16 identified studies; birth setting trials were the most markedly affected, with between 68 % and 85 % of eligible women declining to participate specifically because of preference for a particular healthcare setting. Recruitment into substance abuse and chemotherapy setting studies was also notably affected by preferences. Only four trials used a preference design: the proportion of eligible patients choosing to participate via a preference group ranged from between 33 % and 67 %. In trials of healthcare settings, accrual may be seriously affected by patient preferences. The use of trial designs which incorporate a preference component should therefore strongly be considered. When designing such trials, investigators should consider settings to be complex interventions, which are likely to have linked components which may be difficult to control for. Careful thought is also needed regarding the choice of comparator settings and the most appropriate outcome measures to be used.
Safety in the Chemical Laboratory
ERIC Educational Resources Information Center
Steere, Norman V., Ed.
1973-01-01
Suggests laboratory instructors preserve the necessary evidence after an incident in classroom. Included is a checklist for gathering evidence that trial lawyers will need to present defense adequately. (CC)
Robust inference for group sequential trials.
Ganju, Jitendra; Lin, Yunzhi; Zhou, Kefei
2017-03-01
For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests. Copyright © 2017 John Wiley & Sons, Ltd.
Topical non-steroidal anti-inflammatory agents for diabetic cystoid macular oedema.
Sahoo, Soumendra; Barua, Ankur; Myint, Kay Thi; Haq, Adnaan; Abas, Adinegara B L; Nair, N S
2015-02-16
Diabetic cystoid macular oedema (CMO) is a condition which involves fluid accumulation in the inner portion of the retina. It often follows changes in retinal blood vessels which enhance the fluid to come out of vessels. Although it may be asymptomatic, symptoms are primarily painless loss of central vision, often with the complaint of seeing black spots in front of the eye.It is reported that CMO may resolve spontaneously, or fluctuate for months, before causing loss of vision. If left untreated or undiagnosed, progression of CMO may lead to permanent visual loss.It has been noted that patients with diabetic retinopathy have elevated inflammatory markers, and therefore it is likely that inflammation aids in the progression of vascular disease in these patients. Several topical non-steroidal anti-inflammatory drugs (NSAIDs) such as ketorolac 0.5%, bromfenac 0.09%, and nepafenac 0.1%, have therefore also been used topically to treat chronic diabetic CMO. Hence this review was conducted to find out the effects of topical NSAIDs in diabetic CMO. To assess the effects of topical non-steroidal anti-inflammatory drugs (NSAIDs) for diabetic cystoid macular oedema (CMO). We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to January 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 12 January 2015. Randomised controlled trials (RCTs) and quasi-RCTs investigating the effects of topically applied NSAIDs in the treatment of people with diabetic CMO aged 18 years of age or over. Two review authors independently assessed trial eligibility and screened all available titles and abstracts for inclusion. There were no discrepancies and we did not have to contact trial investigators for missing data. We did not identify any RCTs matching the inclusion criteria for this review. The review did not identify any RCTs investigating the effects of topical NSAIDs in the treatment of diabetic CMO. Most of the studies identified through the electronic searches had been conducted to analyse the effect of topical NSAIDs for pseudophakic CMO.In the absence of high quality evidence, clinicians need to use their clinical judgement and other low level evidence, such as observational non-randomised trials, to decide whether to use topical NSAIDs in cases of diabetic CMO.More research is needed to better understand the cause of this condition and its pathophysiology. This systematic review has identified the need for well designed, adequately powered RCTs to assess possible beneficial and adverse effects of topical NSAIDs in people with diabetic CMO. Future trials should aim to include a large sample size with an adequate follow-up period of up to one year.
Schaefert, Rainer; Klose, Petra; Moser, Gabriele; Häuser, Winfried
2014-06-01
To assess the efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome by a meta-analysis of randomized controlled trials. Studies were identified by a literature search of the databases Allied and Complementary Medicine Database, Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, PubMed, PsycINFO, and Scopus (from inception to June 30, 2013). Primary outcomes were adequate symptom relief, global gastrointestinal score, and safety. Summary relative risks (RRs) with number needed to treat (NNT) and standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were calculated using random-effects models. Eight randomized controlled trials with a total of 464 patients and a median of 8.5 (7-12) hypnosis sessions over a median of 12 (5-12) weeks were included into the analysis. At the end of therapy, hypnosis was superior to control conditions in producing adequate symptom relief (RR, 1.69 [95% CI = 1.14-2.51]; NNT, 5 [3-10]) and in reducing global gastrointestinal score (SMD, 0.32 [95% CI = -0.56 to -0.08]). At long-term follow-up, hypnosis was superior to controls in adequate symptom relief (RR, 2.17 [95% CI = 1.22-3.87]; NNT, 3 [2-10]), but not in reducing global gastrointestinal score (SMD, -0.57 [-1.40 to 0.26]). One (0.4%) of 238 patients in the hypnosis group dropped out due to an adverse event (panic attack). This meta-analysis demonstrated that hypnosis was safe and provided long-term adequate symptom relief in 54% of patients with irritable bowel syndrome refractory to conventional therapy.
2011-01-01
Background Adequate reporting of safety in publications of randomized controlled trials (RCTs) is a pre-requisite for accurate and comprehensive profile evaluation of conventional as well as complementary and alternative medicine (CAM) treatments. Clear and concise information on the definition, frequency, and severity of adverse events (AEs) is necessary for assessing the benefit-harm ratio of any intervention. The objectives of this study are to assess the quality of safety reporting in CAM RCTs; to explore the influence of different trial characteristics on the quality of safety reporting. Methods Survey of safety reporting in RCTs published in 2009 across 15 widely used CAM interventions identified from the Cochrane Collaboration's CAM Field specialized register of trials. Primary outcome measures, the adequacy of reporting of AEs; was defined and categorized according to the CONSORT for harms extension; the percentage of words devoted to the reporting of safety in the entire report and in the results section. Results Two-hundred and five trials were included in the review. Of these, 15% (31/205) reported that no harms were observed during the trial period. Of the remaining 174 trials reporting any safety information, only 21% (36/174) had adequate safety reporting. For all trials, the median percentage of words devoted to the reporting of safety in the results section was 2.6. Moreover, 69% (n = 141) of all trials devoted a lesser or equal percentage of words to safety compared to author affiliations. Of the predictor variables used in regression analysis, multicenter trials had more words devoted to safety in the results section than single centre trials (P = 0.045). Conclusions An evaluation of safety reporting in the reports of CAM RCTs across 15 different CAM interventions demonstrated that the reporting of harms was largely inadequate. The quality of reporting safety information in primary reports of CAM randomized trials requires improvement. PMID:21859470
Vilela-Martin, José Fernando; Giollo-Junior, Luiz Tadeu; Chiappa, Gaspar Rogério; Cipriano-Junior, Gerson; Vieira, Paulo José Cardoso; dos Santos Ricardi, Fábio; Paz-Landim, Manoel Ildefonso; de Andrade, Days Oliveira; Cestário, Elizabeth do Espírito Santo; Cosenso-Martin, Luciana Neves; Yugar-Toledo, Juan Carlos; Cipullo, José Paulo
2016-03-29
Resistant hypertension (RH) treatment requires an adequate and intense therapeutic approach. However, the results are not always satisfactory despite intensive treatment. Of the different pathophysiological mechanisms involved in the pathogenesis of RH, sympathetic overstimulation and therapies that block the sympathetic system have been widely studied. These approaches, however, are invasive and expensive. Another possible approach is by transcutaneous electrical nerve stimulation (TENS), a noninvasive method that modulates activity by using low-frequency transcutaneous electrical stimulation to inhibit primary afferent pathways. Thus, the current study will evaluate the effect of applying TENS in the cervicothoracic region of subjects with RH and will seek to develop a new low-cost and readily available therapy to treat this group of hypertensive individuals. This is a randomized, single blind (subject), parallel-assignment study controlled with a sham group and including participants aged 40 to 70 years with resistant hypertension. The trial has two arms: the treatment and control (sham group). The treatment group will be submitted to the stimulation procedure (TENS). The sham group will not be submitted to stimulation. The primary outcomes will be a reduction in the peripheral blood pressure and adverse events. The secondary outcomes will be a reduction the central blood pressure. The study will last 30 days. The sample size was calculated assuming an alpha error of 5 % to reject the null hypothesis with a statistical power of 80 %, thereby resulting in 28 participants per group (intervention versus sham). In recent decades, RH has become very common and costly. Adequate control requires several drugs, and in many cases, treatment is not successful. Sympathetic nervous system inhibition by renal denervation and central inhibition have significant effects in reducing BP; however, these treatments are costly and invasive. Another type of sympathetic nervous system inhibition can also be noninvasively achieved by electric current. Therefore, the application of TENS may be a new therapeutic option for treating resistant hypertensive individuals. Clinical Trials NCT02365974.
ERIC Educational Resources Information Center
Aminov, Tahir; Magsumov, Timur; Sayakhov, Ruslan; Yepaneshnikov, Vladimir; Nasipov, Ilshat; Aitov, Valerie
2018-01-01
The article describes the educational opportunities of Muslim religious sources in overcoming difficult life situations by a person. An individual cannot claim to be completely aware of the causes of any problems, but he or she ought to learn how to develop an adequate attitude to the very fact of their occurrence. Trials should be taken as…
Sermsathanasawadi, Nuttawut; Tarapongpun, Tanakorn; Pianchareonsin, Rattana; Puangpunngam, Nattawut; Wongwanit, Chumpol; Chinsakchai, Khamin; Mutirangura, Pramook; Ruangsetakit, Chanean
2017-01-01
Objective A randomized clinical trial was performed to compare the effectiveness of unmarked bandages and customized bandages with visual markers in reproducing the desired sub-bandage pressure during self-bandaging by patients. Method Ninety patients were randomly allocated to two groups ("customized bandages" and "unmarked bandages") and asked to perform self-bandaging three times. The achievement of a pressure between 35 and 45 mmHg in at least two of the three attempts was defined as adequate quality. Results Adequate quality was achieved by 33.0% when applying the unmarked bandages, and 60.0% when applying the customized bandages ( p = 0.02). Use of the customized bandage and previous experience of bandaging were independent predictors for the achievement of the predetermined sub-bandage pressure ( p = 0.005 and p = 0.021, respectively). Conclusion Customized bandages may achieve predetermined sub-bandage pressures more closely than standard, unmarked, compression bandages. Clinical trials registration ClinicalTrials.gov (NCT02729688). Effectiveness of a Pressure Indicator Guided and a Conventional Bandaging in Treatment of Venous Leg Ulcer. https://clinicaltrials.gov/ct2/show/NCT02729688.
18 CFR 284.503 - Market-power determination.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...
18 CFR 284.503 - Market-power determination.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...
18 CFR 284.503 - Market-power determination.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...
18 CFR 284.503 - Market-power determination.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...
Statistical inference involving binomial and negative binomial parameters.
García-Pérez, Miguel A; Núñez-Antón, Vicente
2009-05-01
Statistical inference about two binomial parameters implies that they are both estimated by binomial sampling. There are occasions in which one aims at testing the equality of two binomial parameters before and after the occurrence of the first success along a sequence of Bernoulli trials. In these cases, the binomial parameter before the first success is estimated by negative binomial sampling whereas that after the first success is estimated by binomial sampling, and both estimates are related. This paper derives statistical tools to test two hypotheses, namely, that both binomial parameters equal some specified value and that both parameters are equal though unknown. Simulation studies are used to show that in small samples both tests are accurate in keeping the nominal Type-I error rates, and also to determine sample size requirements to detect large, medium, and small effects with adequate power. Additional simulations also show that the tests are sufficiently robust to certain violations of their assumptions.
Coppola, Antonio; Windyga, Jerzy; Tufano, Antonella; Yeung, Cindy; Di Minno, Matteo Nicola Dario
2015-02-09
In people with haemophilia or other congenital bleeding disorders undergoing surgical interventions, haemostatic treatment is needed in order to correct the underlying coagulation abnormalities and minimise the bleeding risk. This treatment varies according to the specific haemostatic defect, its severity and the type of surgical procedure. The aim of treatment is to ensure adequate haemostatic coverage for as long as the bleeding risk persists and until wound healing is complete. To assess the effectiveness and safety of different haemostatic regimens (type, dose and duration, modality of administration and target haemostatic levels) administered in people with haemophilia or other congenital bleeding disorders for preventing bleeding complications during and after surgical procedures. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies 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 the last search: 20 November 2014. Randomised and quasi-randomised controlled trials comparing any hemostatic treatment regimen to no treatment or to another active regimen in children and adults with haemophilia or other congenital bleeding disorders undergoing any surgical intervention. Two authors independently assessed trials (eligibility and risks of bias) and extracted data. Meta-analyses were performed on available and relevant data. Of the 16 identified trials, four (112 participants) were eligible for inclusion.Two trials evaluated 59 people with haemophilia A and B undergoing 63 dental extractions. Trials compared the use of a different type (tranexamic acid or epsilon-aminocaproic acid) and regimen of antifibrinolytic agents as haemostatic support to the initial replacement treatment. Neither trial specifically addressed mortality (one of this review's primary outcomes); however, in the frame of safety assessments, no fatal adverse events were reported. The second primary outcome of blood loss was assessed after surgery and these trials showed the reduction of blood loss and requirement of post-operative replacement treatment in people receiving antifibrinolytic agents compared with placebo. The remaining primary outcome of need for re-intervention was not reported by either trial.Two trials reported on 53 people with haemophilia A and B with inhibitors treated with different regimens of recombinant activated factor VII (rFVIIa) for haemostatic coverage of 33 major and 20 minor surgical interventions. Neither of the included trials specifically addressed any of the review's primary outcomes (mortality, blood loss and need for re-intervention). In one trial a high-dose rFVIIa regimen (90 μg/kg) was compared with a low-dose regimen (35 μg/kg); the higher dose showed increased haemostatic efficacy, in particular in major surgery, with shorter duration of treatment, similar total dose of rFVIIa administered and similar safety levels. In the second trial, bolus infusion and continuous infusion of rFVIIa were compared, showing similar haemostatic efficacy, duration of treatment and safety. There is insufficient evidence from randomised controlled trials to assess the most effective and safe haemostatic treatment to prevent bleeding in people with haemophilia or other congenital bleeding disorders undergoing surgical procedures. Ideally large, adequately powered, and well-designed randomised controlled trials would be needed, in particular to address the cost-effectiveness of such demanding treatments in the light of the increasing present economic constraints, and to explore the new challenge of ageing patients with haemophilia or other congenital bleeding disorders. However, performing such trials is always a complex task in this setting and presently does not appear to be a clinical and research priority. Indeed, major and minor surgeries are effectively and safely performed in these individuals in clinical practice, with the numerous national and international recommendations and guidelines providing regimens for treatment in this setting mainly based on data from observational, uncontrolled studies.
Toward a functional definition of a "rare disease" for regulatory authorities and funding agencies.
Clarke, Joe T R; Coyle, Doug; Evans, Gerald; Martin, Janet; Winquist, Eric
2014-12-01
The designation of a disease as "rare" is associated with some substantial benefits for companies involved in new drug development, including expedited review by regulatory authorities and relaxed criteria for reimbursement. How "rare disease" is defined therefore has major financial implications, both for pharmaceutical companies and for insurers or public drug reimbursement programs. All existing definitions are based, somewhat arbitrarily, on disease incidence or prevalence. What is proposed here is a functional definition of rare based on an assessment of the feasibility of measuring the efficacy of a new treatment in conventional randomized controlled trials, to inform regulatory authorities and funding agencies charged with assessing new therapies being considered for public funding. It involves a five-step process, involving significant negotiations between patient advocacy groups, pharmaceutical companies, physicians, and public drug reimbursement programs, designed to establish the feasibility of carrying out a randomized controlled trial with sufficient statistical power to show a clinically significant treatment effect. The steps are as follows: 1) identification of a specific disease, including appropriate genetic definition; 2) identification of clinically relevant outcomes to evaluate efficacy; 3) establishment of the inherent variability of measurements of clinically relevant outcomes; 4) calculation of the sample size required to assess the efficacy of a new treatment with acceptable statistical power; and 5) estimation of the difficulty of recruiting an adequate sample size given the estimated prevalence or incidence of the disorder in the population and the inclusion criteria to be used. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.
Brealey, Stephen D; Atwell, Christine; Bryan, Stirling; Coulton, Simon; Cox, Helen; Cross, Ben; Fylan, Fiona; Garratt, Andrew; Gilbert, Fiona J; Gillan, Maureen GC; Hendry, Maggie; Hood, Kerenza; Houston, Helen; King, David; Morton, Veronica; Orchard, Jo; Robling, Michael; Russell, Ian T; Torgerson, David; Wadsworth, Valerie; Wilkinson, Clare
2007-01-01
Background Poor response rates to postal questionnaires can introduce bias and reduce the statistical power of a study. To improve response rates in our trial in primary care we tested the effect of introducing an unconditional direct payment of £5 for the completion of postal questionnaires. Methods We recruited patients in general practice with knee problems from sites across the United Kingdom. An evidence-based strategy was used to follow-up patients at twelve months with postal questionnaires. This included an unconditional direct payment of £5 to patients for the completion and return of questionnaires. The first 105 patients did not receive the £5 incentive, but the subsequent 442 patients did. We used logistic regression to analyse the effect of introducing a monetary incentive to increase the response to postal questionnaires. Results The response rate following reminders for the historical controls was 78.1% (82 of 105) compared with 88.0% (389 of 442) for those patients who received the £5 payment (diff = 9.9%, 95% CI 2.3% to 19.1%). Direct payments significantly increased the odds of response (adjusted odds ratio = 2.2, 95% CI 1.2 to 4.0, P = 0.009) with only 12 of 442 patients declining the payment. The incentive did not save costs to the trial – the extra cost per additional respondent was almost £50. Conclusion The direct payment of £5 significantly increased the completion of postal questionnaires at negligible increase in cost for an adequately powered study. PMID:17326837
Jaciw, Andrew P; Lin, Li; Ma, Boya
2016-10-18
Prior research has investigated design parameters for assessing average program impacts on achievement outcomes with cluster randomized trials (CRTs). Less is known about parameters important for assessing differential impacts. This article develops a statistical framework for designing CRTs to assess differences in impact among student subgroups and presents initial estimates of critical parameters. Effect sizes and minimum detectable effect sizes for average and differential impacts are calculated before and after conditioning on effects of covariates using results from several CRTs. Relative sensitivities to detect average and differential impacts are also examined. Student outcomes from six CRTs are analyzed. Achievement in math, science, reading, and writing. The ratio of between-cluster variation in the slope of the moderator divided by total variance-the "moderator gap variance ratio"-is important for designing studies to detect differences in impact between student subgroups. This quantity is the analogue of the intraclass correlation coefficient. Typical values were .02 for gender and .04 for socioeconomic status. For studies considered, in many cases estimates of differential impact were larger than of average impact, and after conditioning on effects of covariates, similar power was achieved for detecting average and differential impacts of the same size. Measuring differential impacts is important for addressing questions of equity, generalizability, and guiding interpretation of subgroup impact findings. Adequate power for doing this is in some cases reachable with CRTs designed to measure average impacts. Continuing collection of parameters for assessing differential impacts is the next step. © The Author(s) 2016.
Hiremath, Swapnil; Akbari, Ayub; Shabana, Wael; Fergusson, Dean A; Knoll, Greg A
2013-01-01
Pre-procedural intravenous fluid administration is an effective prophylaxis measure for contrast-induced acute kidney injury. For logistical ease, the oral route is an alternative to the intravenous. The objective of this study was to compare the efficacy of the oral to the intravenous route in prevention of contrast-induced acute kidney injury. A systematic review and meta-analysis of randomised trials with a stratified analysis and metaregression. Databases included MEDLINE (1950 to November 23 2011), EMBASE (1947 to week 47 2011), Cochrane CENTRAL (3(rd) quarter 2011). Two reviewers identified relevant trials and abstracted data. SETTINGS AND POPULATION: Trials including patients undergoing a contrast enhanced procedure. Randomised controlled trial; adult (>18 years) population; comparison of oral versus intravenous volume expansion. Oral route of volume expansion compared to the intravenous route. Any measure of acute kidney injury, need for renal replacement therapy, hospitalization and death. Six trials including 513 patients met inclusion criteria. The summary odds ratio was 1.19 (95% CI 0.46, 3.10, p = 0.73) suggesting no difference between the two routes of volume expansion. There was significant heterogeneity (Cochran's Q = 11.65, p = 0.04; I(2) = 57). In the stratified analysis, inclusion of the five studies with a prespecified oral volume expansion protocol resulted in a shift towards oral volume expansion (OR 0.75, 95% CI 0.37, 1.50, p = 0.42) and also resolved the heterogeneity (Q = 3.19, P = 0.53; I(2) = 0). Small number of studies identified; lack of hard clinical outcomes. The oral route may be as effective as the intravenous route for volume expansion for contrast-induced acute kidney injury prevention. Adequately powered trials with hard endpoints should be done given the potential advantages of oral (e.g. reduced patient burden and cost) over intravenous volume expansion.
2013-01-01
Background Despite recent advances in acute stroke treatment, basilar artery occlusion (BAO) is associated with a death or disability rate of close to 70%. Randomised trials have shown the safety and efficacy of intravenous thrombolysis (IVT) given within 4.5 h and have shown promising results of intra-arterial thrombolysis given within 6 h of symptom onset of acute ischaemic stroke, but these results do not directly apply to patients with an acute BAO because only few, if any, of these patients were included in randomised acute stroke trials. Recently the results of the Basilar Artery International Cooperation Study (BASICS), a prospective registry of patients with acute symptomatic BAO challenged the often-held assumption that intra-arterial treatment (IAT) is superior to IVT. Our observations in the BASICS registry underscore that we continue to lack a proven treatment modality for patients with an acute BAO and that current clinical practice varies widely. Design BASICS is a randomised controlled, multicentre, open label, phase III intervention trial with blinded outcome assessment, investigating the efficacy and safety of additional IAT after IVT in patients with BAO. The trial targets to include 750 patients, aged 18 to 85 years, with CT angiography or MR angiography confirmed BAO treated with IVT. Patients will be randomised between additional IAT followed by optimal medical care versus optimal medical care alone. IVT has to be initiated within 4.5 h from estimated time of BAO and IAT within 6 h. The primary outcome parameter will be favourable outcome at day 90 defined as a modified Rankin Scale score of 0–3. Discussion The BASICS registry was observational and has all the limitations of a non-randomised study. As the IAT approach becomes increasingly available and frequently utilised an adequately powered randomised controlled phase III trial investigating the added value of this therapy in patients with an acute symptomatic BAO is needed (clinicaltrials.gov: NCT01717755). PMID:23835026
Wiangkham, Taweewat; Duda, Joan; Haque, M Sayeed; Price, Jonathan; Rushton, Alison
2016-01-01
Introduction Whiplash-associated disorder (WAD) causes substantial social and economic burden internationally. Up to 60% of patients with WAD progress to chronicity. Research therefore needs to focus on effective management in the acute stage to prevent the development of chronicity. Approximately 93% of patients are classified as WADII (neck complaint and musculoskeletal sign(s)), and in the UK, most are managed in the private sector. In our recent systematic review, a combination of active and behavioural physiotherapy was identified as potentially effective in the acute stage. An Active Behavioural Physiotherapy Intervention (ABPI) was developed through combining empirical (modified Delphi study) and theoretical (social cognitive theory focusing on self-efficacy) evidence. This pilot and feasibility trial has been designed to inform the design of an adequately powered definitive randomised controlled trial. Methods and analysis Two parallel phases. (1) An external pilot and feasibility cluster randomised double-blind (assessor and participants), parallel two-arm (ABPI vs standard physiotherapy) clinical trial to evaluate procedures and feasibility. Six UK private physiotherapy clinics will be recruited and cluster randomised by a computer-generated randomisation sequence. Sixty participants (30 each arm) will be assessed at recruitment (baseline) and at 3 months postbaseline. The planned primary outcome measure is the neck disability index. (2) An embedded exploratory qualitative study using semistructured indepth interviews (n=3–4 physiotherapists) and a focus group (n=6–8 patients) and entailing the recruitment of purposive samples will explore perceptions of the ABPI. Quantitative data will be analysed descriptively. Qualitative data will be coded and analysed deductively (identify themes) and inductively (identify additional themes). Ethics and dissemination This trial is approved by the University of Birmingham Ethics Committee (ERN_15-0542). Trial registration number ISRCTN84528320. PMID:27412105
Wilhelm-Leen, Emilee R; Winkelmayer, Wolfgang C
2015-07-01
Epoetin alfa (EPO) and darbepoetin alfa (DPO) are erythropoiesis-stimulating agents that are widely and interchangeably used for the treatment of anemia in patients with advanced chronic kidney disease and end-stage renal disease. No study has specifically compared the risks of hard study outcomes between EPO and DPO, including mortality. Systematic review of the literature and meta-analysis. Patients enrolled in randomized trials comparing EPO versus DPO for the treatment of anemia in adults with chronic kidney disease, including those requiring dialysis. We conducted a systematic search of the literature (PubMed, CENTRAL, SCOPUS, and EMBASE, all years) and industry resources, using predefined search terms and data abstraction tools. We then summarized key characteristics and findings of these trials and performed a random-effects meta-analysis of trials with at least 3 months' duration to identify the summary OR of mortality between patients randomly assigned to DPO versus EPO. DPO versus EPO. All-cause mortality. We identified 9 trials that met the stated inclusion criteria. Overall, 2,024 patients were included in the meta-analysis, of whom 126 died during follow-up, which ranged from 20 to 52 weeks. We found no significant difference in mortality between patients randomly assigned to DPO versus EPO (OR, 1.33; 95% CI, 0.88-2.01). No treatment heterogeneity across studies was detected (Q statistic=4.60; P=0.8). Generalizability to nontrial populations is uncertain. Few trials directly comparing DPO and EPO have been conducted and follow-up was limited. In aggregate, no effect of specific erythropoiesis-stimulating agent on mortality was identified, but the confidence limits were wide and remained compatible with considerable harm from DPO. Absent adequately powered randomized trials, observational postmarketing comparative effectiveness studies comparing these erythropoiesis-stimulating agents are required to better characterize the long-term safety profiles of these agents. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Bjorklund, Ashley R; Odongkara Mpora, Beatrice; Steiner, Marie E; Fischer, Gwenyth; Davey, Cynthia S; Slusher, Tina M
2018-06-18
While bubble continuous positive airway pressure (bCPAP) is commonly used in low- and middle-income countries (LMIC) to support neonates with respiratory distress, there are limited non-invasive support options for non-neonatal children. To demonstrate safety of a new device designed to support children during respiratory distress in LMIC. A paediatric bCPAP device was designed called SEAL-bCPAP (Simplified Ear-plug Adapted-bCPAP). SEAL-bCPAP is constructed from inexpensive, easily obtainable materials. The nasal prong interface was modified from previously described neonatal bCPAP set-ups using commercial ear-plug material to improve nasal seal. A prospective interventional study was conducted to evaluate safety in children with respiratory distress treated with SEAL-bCPAP. Patients aged 30 days to 5 years presenting to a hospital in northern Uganda from July 2015 to June 2016 were screened. Those with moderate-severe respiratory distress and/or hypoxia despite nasal cannula oxygen were eligible for study. Enrolled patients were supported with SEAL-bCPAP until respiratory improvement or death. Complications attributable to SEAL-bCPAP were recorded. Clinical outcomes were compared with historical control pre-trial data. Eighty-three of 87 enrolled patients were included in the final analysis. No patients had significant SEAL-bCPAP complications. Five patients had mild complications which resolved (four with nasal irritation and one with abdominal distention). Trial patients had significant (p < 0.0001) improvement in their TAL score, respiratory rate and O 2 sat after 2 h of SEAL-bCPAP. Fifty-two of 64 patients (62.7%) with severe illness at Time1 did not have severe illness at Time2 (after 2 h of SEAL-bCPAP) (p < 0.0001). Unadjusted mortality rates were 12.2% (6/49) and 9.6% (8/83), respectively, for pre-trial (historical control) and trial patients (p = 0.64); the study was not powered to show efficacy. The SEAL-bCPAP device is safe for treatment of respiratory distress in non-neonatal children in LMIC. There is a trend toward decreased mortality that should be evaluated with adequately powered clinical trials.
9 CFR 3.50 - Facilities, general.
Code of Federal Regulations, 2012 CFR
2012-01-01
... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...
9 CFR 3.50 - Facilities, general.
Code of Federal Regulations, 2014 CFR
2014-01-01
... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...
9 CFR 3.50 - Facilities, general.
Code of Federal Regulations, 2013 CFR
2013-01-01
... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...
Adjuvant radiation trials for high-risk breast cancer patients: adequacy of lymphadenectomy.
Silberman, A W; Sarna, G P; Palmer, D
2000-06-01
The recently published, widely publicized adjuvant radiation trials from Denmark and Canada concluded that the addition of postoperative radiotherapy (XRT) to modified radical mastectomy (MRM) and adjuvant chemotherapy reduces locoregional recurrences and prolongs survival in high-risk premenopausal patients with breast cancer. Our thesis is that adequate lymphadenectomies were not performed in either study. Consequently, the conclusion to these studies is not applicable to those patients who have undergone adequate surgery. To better assess adequate lymph node yield from an MRM, a retrospective review was performed on 215 consecutive patients treated surgically for invasive breast cancer. Data from this review were compared with the surgical data from the above-mentioned radiotherapy trials. In a group of 131 patients who had MRM, the average number of nodes removed was 26 (median, 25), and 75.5% of the specimens had 20 or more lymph nodes. In 73 patients who underwent segmental mastectomy with axillary lymph node dissection, both the average and the median number of lymph nodes removed were 24, and 68.9% had 20 or more nodes. These data compare to the Danish radiation trial in which a median of 7 lymph nodes were removed (with 76% of the patients having 9 or fewer lymph nodes in the specimen) and to the Canadian radiation trial in which a median of 11 lymph nodes were removed. In addition, in our breast cancer patients with positive nodes (84 of 204; 41.2%), 45.2.% (38 of 84) had more than three positive nodes compared with 29.8% in the Danish study and 35% in the Canadian study. Our surgical data are sufficiently different from those of the Danish and Canadian studies to indicate that, in those studies, incomplete lymph node dissections were performed and that residual disease was left behind in the axilla in some or all of the patients. The addition of XRT in the setting of residual axillary disease may compensate for an inadequate operation and yield an acceptable oncological result; however, these studies did not provide an adequate comparison with a well-performed MRM without XRT. In the absence of documented benefit, XRT should not be routinely added if a complete lymph node dissection has been performed.
Measures of rowing performance.
Smith, T Brett; Hopkins, Will G
2012-04-01
Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.
Predicting High-Power Performance in Professional Cyclists.
Sanders, Dajo; Heijboer, Mathieu; Akubat, Ibrahim; Meijer, Kenneth; Hesselink, Matthijs K
2017-03-01
To assess if short-duration (5 to ~300 s) high-power performance can accurately be predicted using the anaerobic power reserve (APR) model in professional cyclists. Data from 4 professional cyclists from a World Tour cycling team were used. Using the maximal aerobic power, sprint peak power output, and an exponential constant describing the decrement in power over time, a power-duration relationship was established for each participant. To test the predictive accuracy of the model, several all-out field trials of different durations were performed by each cyclist. The power output achieved during the all-out trials was compared with the predicted power output by the APR model. The power output predicted by the model showed very large to nearly perfect correlations to the actual power output obtained during the all-out trials for each cyclist (r = .88 ± .21, .92 ± .17, .95 ± .13, and .97 ± .09). Power output during the all-out trials remained within an average of 6.6% (53 W) of the predicted power output by the model. This preliminary pilot study presents 4 case studies on the applicability of the APR model in professional cyclists using a field-based approach. The decrement in all-out performance during high-intensity exercise seems to conform to a general relationship with a single exponential-decay model describing the decrement in power vs increasing duration. These results are in line with previous studies using the APR model to predict performance during brief all-out trials. Future research should evaluate the APR model with a larger sample size of elite cyclists.
Comparison of rheumatoid arthritis clinical trial outcome measures: a simulation study.
Anderson, Jennifer J; Bolognese, James A; Felson, David T
2003-11-01
Isolated studies have suggested that continuous measures of response may be better than predefined, dichotomous definitions (e.g., the American College of Rheumatology 20% improvement criteria [ACR20]) for discriminating between rheumatoid arthritis (RA) treatments. Our goal was to determine the statistical power of predefined dichotomous outcome measures (termed "a priori"), compared with that of continuous measures derived from trial data in which there was no predefined response threshold (termed "data driven"), and to evaluate the sensitivity to change of these measures in the context of different treatments and early versus later-stage disease. In order to generalize beyond results from a single trial, we performed simulation studies. We obtained summary data from trials comparing disease-modifying antirheumatic drugs (DMARDs) and from comparative coxib-placebo trials to test the power of 2 a priori outcomes, the ACR20 and improvement of the Disease Activity Score (DDAS), as well as 2 data-driven outcomes. We studied patients with early RA and those with later-stage RA (duration of <4 years and 4-9 years, respectively). We performed simulation studies, using the interrelationship of ACR core set measures in the trials to generate multiple trial data sets consistent with the original data. The data-driven outcomes had greater power than did the a priori measures. The DMARD comparison was more powerful in early disease than in later-stage disease (the sample sizes needed to achieve 80% power for the most powerful test were 64 for early disease versus 100 for later disease), but the coxib-versus-placebo comparison was less powerful in early disease than in later disease (the sample sizes needed to achieve 80% power were 200 and 100, respectively). When the effects of treatment on core set items were small and/or inconsistent, power was reduced, particularly for a less broadly based outcome (e.g., DDAS) compared with the ACR20. The simulation studies demonstrate that data-driven outcome definitions can provide better sensitivity to change than does the ACR20 or DDAS. Using such methods would improve power, but at the expense of trial standardization. The studies also show how patient population and treatment characteristics affect the power of specific outcome measures in RA clinical trials, and provide quantification of those effects.
14 CFR 171.113 - Installation requirements.
Code of Federal Regulations, 2013 CFR
2013-01-01
... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...
14 CFR 171.113 - Installation requirements.
Code of Federal Regulations, 2014 CFR
2014-01-01
... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...
14 CFR 171.113 - Installation requirements.
Code of Federal Regulations, 2012 CFR
2012-01-01
... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...
30 CFR 75.517 - Power wires and cables; insulation and protection.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...
30 CFR 75.517 - Power wires and cables; insulation and protection.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...
30 CFR 75.517 - Power wires and cables; insulation and protection.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...
30 CFR 75.517 - Power wires and cables; insulation and protection.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...
30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.
Code of Federal Regulations, 2011 CFR
2011-07-01
... power conductors and telephone wires. 77.508 Section 77.508 Mineral Resources MINE SAFETY AND HEALTH... arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...
30 CFR 75.517 - Power wires and cables; insulation and protection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...
30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.
Code of Federal Regulations, 2010 CFR
2010-07-01
... power conductors and telephone wires. 77.508 Section 77.508 Mineral Resources MINE SAFETY AND HEALTH... arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-08
... Company, Davis-Besse Nuclear Power Station; Environmental Assessment And Finding of No Significant Impact... operation of the Davis-Besse Nuclear Power Station, Unit 1 (DBNPS), located in Ottawa County, Ohio. In... the reactor coolant pressure boundary of light-water nuclear power reactors provide adequate margins...
Hampson, Lisa V; Williamson, Paula R; Wilby, Martin J; Jaki, Thomas
2017-01-01
Just over half of publicly funded trials recruit their target sample size within the planned study duration. When recruitment targets are missed, the funder of a trial is faced with the decision of either committing further resources to the study or risk that a worthwhile treatment effect may be missed by an underpowered final analysis. To avoid this challenging situation, when there is insufficient prior evidence to support predicted recruitment rates, funders now require feasibility assessments to be performed in the early stages of trials. Progression criteria are usually specified and agreed with the funder ahead of time. To date, however, the progression rules used are typically ad hoc. In addition, rules routinely permit adaptations to recruitment strategies but do not stipulate criteria for evaluating their effectiveness. In this paper, we develop a framework for planning and designing internal pilot studies which permit a trial to be stopped early if recruitment is disappointing or to continue to full recruitment if enrolment during the feasibility phase is adequate. This framework enables a progression rule to be pre-specified and agreed upon prior to starting a trial. The novel two-stage designs stipulate that if neither of these situations arises, adaptations to recruitment should be made and subsequently evaluated to establish whether they have been successful. We derive optimal progression rules for internal pilot studies which minimise the expected trial overrun and maintain a high probability of completing the study when the recruitment rate is adequate. The advantages of this procedure are illustrated using a real trial example.
Powered versus manual toothbrushing for oral health.
Yaacob, Munirah; Worthington, Helen V; Deacon, Scott A; Deery, Chris; Walmsley, A Damien; Robinson, Peter G; Glenny, Anne-Marie
2014-06-17
Removing dental plaque may play a key role maintaining oral health. There is conflicting evidence for the relative merits of manual and powered toothbrushing in achieving this. This is an update of a Cochrane review first published in 2003, and previously updated in 2005. To compare manual and powered toothbrushes in everyday use, by people of any age, in relation to the removal of plaque, the health of the gingivae, staining and calculus, dependability, adverse effects and cost. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 23 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE via OVID (1946 to 23 January 2014), EMBASE via OVID (1980 to 23 January 2014) and CINAHL via EBSCO (1980 to 23 January 2014). We searched the US National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials of at least four weeks of unsupervised powered toothbrushing versus manual toothbrushing for oral health in children and adults. We used standard methodological procedures expected by The Cochrane Collaboration. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months). Fifty-six trials met the inclusion criteria; 51 trials involving 4624 participants provided data for meta-analysis. Five trials were at low risk of bias, five at high and 46 at unclear risk of bias.There is moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short term (standardised mean difference (SMD) -0.50 (95% confidence interval (CI) -0.70 to -0.31); 40 trials, n = 2871) and long term (SMD -0.47 (95% CI -0.82 to -0.11; 14 trials, n = 978). These results correspond to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and 21% reduction long term. Both meta-analyses showed high levels of heterogeneity (I(2) = 83% and 86% respectively) that was not explained by the different powered toothbrush type subgroups.With regard to gingivitis, there is moderate quality evidence that powered toothbrushes again provide a statistically significant benefit when compared with manual toothbrushes both in the short term (SMD -0.43 (95% CI -0.60 to -0.25); 44 trials, n = 3345) and long term (SMD -0.21 (95% CI -0.31 to -0.12); 16 trials, n = 1645). This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness index respectively. Both meta-analyses showed high levels of heterogeneity (I(2) = 82% and 51% respectively) that was not explained by the different powered toothbrush type subgroups.The number of trials for each type of powered toothbrush varied: side to side (10 trials), counter oscillation (five trials), rotation oscillation (27 trials), circular (two trials), ultrasonic (seven trials), ionic (four trials) and unknown (five trials). The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points. Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses.Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.
Bautista, Francisco; Moreno, Lucas; Marshall, Lynley; Pearson, Andrew D J; Geoerger, Birgit; Paoletti, Xavier
2017-11-01
Dose-escalation trials aim to identify the maximum tolerated dose and, importantly, the recommended phase II dose (RP2D) and rely on the occurrence of dose-limiting toxicities (DLTs) during the first treatment cycle. Molecularly targeted agents (MTAs) often follow continuous and prolonged administrations, displaying a distinct toxicity profile compared to conventional chemotherapeutics, and classical DLT criteria might not be appropriate to evaluate MTAs' toxicity. We investigated this issue in children. The Innovative Therapies for Children with Cancer Consortium (ITCC) phase I trials of novel anticancer agents between 2004 and 2015 were analysed. Data from investigational product, trial design, items defining DLT/RP2D were extracted. A survey on dose-escalation process, DLTs and RP2D definition was conducted among the ITCC clinical trials committee members. Thirteen phase I trials with 15 dose-escalation cohorts were analysed. They explored 11 MTAs and 2 novel cytotoxics; 12 evaluated DLT during cycle 1. Definition of DLT was heterogeneous: Grade III-IV haematologic toxicities that were transient or asymptomatic and grade III-IV non-haematological toxicities manageable with adequate supportive care were often excluded, whereas some included dose intensity or grade II toxicities into DLT. None of the studies considered delayed toxicity into the RP2D definition. DLTs should be homogeneously defined across trials, limiting the number of exceptions due to specific toxicities. Dose escalation should still be based on safety data from cycle 1, but delayed and overall toxicities, pharmacokinetic parameters and pharmacodynamic data should be considered to refine the final RP2D. The evaluation of long-term toxicity in the developing child cannot be adequately addressed in early trials. Copyright © 2017 Elsevier Ltd. All rights reserved.
14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2013 CFR
2013-01-01
... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...
14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2014 CFR
2014-01-01
... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...
14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2010 CFR
2010-01-01
... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...
14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2012 CFR
2012-01-01
... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...
14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2011 CFR
2011-01-01
... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...
ERIC Educational Resources Information Center
Social Policy, 1976
1976-01-01
Priorities on the agenda include fair representation and participation in the political process, equal education and training, meaningful work and adequate compensation, equal access to economic power, adequate housing, physical safety, and fair treatment by and equal access to media and the arts. (Author/AM)
Theta EEG dynamics of the error-related negativity.
Trujillo, Logan T; Allen, John J B
2007-03-01
The error-related negativity (ERN) is a response-locked brain potential (ERP) occurring 80-100ms following response errors. This report contrasts three views of the genesis of the ERN, testing the classic view that time-locked phasic bursts give rise to the ERN against the view that the ERN arises from a pure phase-resetting of ongoing theta (4-7Hz) EEG activity and the view that the ERN is generated - at least in part - by a phase-resetting and amplitude enhancement of ongoing theta EEG activity. Time-domain ERP analyses were augmented with time-frequency investigations of phase-locked and non-phase-locked spectral power, and inter-trial phase coherence (ITPC) computed from individual EEG trials, examining time courses and scalp topographies. Simulations based on the assumptions of the classic, pure phase-resetting, and phase-resetting plus enhancement views, using parameters from each subject's empirical data, were used to contrast the time-frequency findings that could be expected if one or more of these hypotheses adequately modeled the data. Error responses produced larger amplitude activity than correct responses in time-domain ERPs immediately following responses, as expected. Time-frequency analyses revealed that significant error-related post-response increases in total spectral power (phase- and non-phase-locked), phase-locked power, and ITPC were primarily restricted to the theta range, with this effect located over midfrontocentral sites, with a temporal distribution from approximately 150-200ms prior to the button press and persisting up to 400ms post-button press. The increase in non-phase-locked power (total power minus phase-locked power) was larger than phase-locked power, indicating that the bulk of the theta event-related dynamics were not phase-locked to response. Results of the simulations revealed a good fit for data simulated according to the phase-locking with amplitude enhancement perspective, and a poor fit for data simulated according to the classic view and the pure phase-resetting view. Error responses produce not only phase-locked increases in theta EEG activity, but also increases in non-phase-locked theta, both of which share a similar topography. The findings are thus consistent with the notion advanced by Luu et al. [Luu P, Tucker DM, Makeig S. Frontal midline theta and the error-related negativity; neurophysiological mechanisms of action regulation. Clin Neurophysiol 2004;115:1821-35] that the ERN emerges, at least in part, from a phase-resetting and phase-locking of ongoing theta-band activity, in the context of a general increase in theta power following errors.
Zhang, Guo-Qiang; Chen, Jin-Liang; Zhao, Yong
2016-03-01
Renal scarring after acute pyelonephritis (APN) in children is of concern and in the worst cases leads to long-term cardiovascular morbidity. There are reports that vitamin A may alleviate renal damage following APN. We conducted a meta-analysis to investigate the role of vitamin A in the alleviation of renal damage. We searched PubMed, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, the Cochrane Library) and the Wang Fang database (Chinese) from their inception to February 3, 2015 for randomized controlled trials (RCTs) investigating vitamin A and renal damage. Primary outcome was number of patients/kidneys with renal damage, defined as persistence of photopenic lesions based on technetium-99m dimercaptosuccinic acid renal scintigraphy. We calculated pooled relative risks for renal damage in the vitamin A group. Four RCTs, involving a total of 248 patients aged 1-144 months (120 in experimental group, 128 in control group), were included in the meta-analysis. Vitamin A was inversely associated with renal damage (relative risk 0.53, 95 % confidence interval 0.43, 0.67) when compared with placebo group after an average follow-up of 5 months. Current evidence indicates that vitamin A may exert a preventive effect on renal damage in children with APN. However, this finding largely relies on a few studies of low methodological quality, i.e., high risk of selection bias, performance bias and attrition bias. Hence, high-quality and adequately powered RCTs are warranted.
Nutritional targets to enhance exercise performance in chronic obstructive pulmonary disease.
van de Bool, Coby; Steiner, Michael C; Schols, Annemie M W J
2012-11-01
This review presents current knowledge regarding the rationale and efficacy of nutrition as an ergogenic aid to enhance the effects of exercise and training in chronic obstructive pulmonary disease (COPD). Altered body composition and skeletal muscle dysfunction in COPD suggest that exercise capacity can be targeted via several metabolic routes. Muscle metabolic alterations in COPD include a reduced oxidative metabolism and enhanced susceptibility for oxidative stress. Muscle wasting may be associated with deficiencies of vitamin D and low branched-chain amino acid levels. Exercise training is of established benefit in COPD but clear-cut clinical trial evidence to support the performance enhancing effect of nutritional intervention is lacking. One randomized controlled trial suggested that augmentation of training with polyunsaturated fatty acids may improve exercise capacity. Conflicting results are reported on dietary creatine supplementation in patients with COPD receiving pulmonary rehabilitation and results from acute intervention studies do not directly imply long-term effects of glutamate or glutamine supplementation as an ergogenic aid in COPD. Recent data indicate that not only muscle but also visceral fat may be an important additional target for combined nutrition and exercise intervention in COPD to improve physical performance and decrease cardiometabolic risk. There is a clear need for adequately powered and controlled intervention and maintenance trials to establish the role of nutritional supplementation in the enhancement of exercise performance and training and the wider management of the systemic features of the disease.
Ravinetto, Raffaella; De Nys, Katelijne; Boelaert, Marleen; Diro, Ermias; Meintjes, Graeme; Adoke, Yeka; Tagbor, Harry; Casteels, Minne
2015-12-30
Non-commercial clinical research plays an increasingly essential role for global health. Multiple partners join in international consortia that operate under the limited timeframe of a specific funding period. One organisation (the sponsor) designs and carries out the trial in collaboration with research partners, and is ultimately responsible for the trial's scientific, ethical, regulatory and legal aspects, while another organization, generally in the North (the funder), provides the external funding and sets funding conditions. Even if external funding mechanisms are key for most non-commercial research, the dependence on an external funder's policies may heavily influence the choices of a sponsor. In addition, the competition for accessing the available external funds is great, and non-commercial sponsors may not be in a position to discuss or refuse standard conditions set by a funder. To see whether the current definitions adequately address the intricacies of sponsorship in externally-funded trials, we looked at how a "sponsor" of clinical trials is defined in selected international guidelines, with particular focus on international Good Clinical Practices codes, and in selected European and African regulations/legislations. Our limited analysis suggests that the sponsors definition from the 1995 WHO Good Clinical Practices code has been integrated as such into many legislations, guidelines and regulations, and that it is not adequate to cover today's reality of funding arrangements in global health, where the legal responsibility and the funding source are de facto split. In agreement with other groups, we suggest that the international Good Clinical Practices codes should be updated to reflect the reality of non-commercial clinical research. In particular, they should explicitly include the distinction between commercial and non-commercial sponsors, and provide guidance to non-commercial sponsors for negotiating with external funding agencies and other research counterparts. Non-commercial sponsors of clinical trials should surely invest in the development of adequate legal, administrative and management skills. By acknowledging their role and specificities, and by providing them with adapted guidance, the international Good Clinical Practices codes would provide valuable guidance and support to non-commercial clinical research, whose relevance for global health is increasingly evident.
Thomson, Denise; Hartling, Lisa; Cohen, Eyal; Vandermeer, Ben; Tjosvold, Lisa; Klassen, Terry P.
2010-01-01
Background The objective of this study was to describe randomized controlled trials (RCTs) and controlled clinical trials (CCTs) in child health published between 1948 and 2006, in terms of quantity, methodological quality, and publication and trial characteristics. We used the Trials Register of the Cochrane Child Health Field for overall trends and a sample from this to explore trial characteristics in more detail. Methodology/Principal Findings We extracted descriptive data on a random sample of 578 trials. Ninety-six percent of the trials were published in English; the percentage of child-only trials was 90.5%. The most frequent diagnostic categories were infectious diseases (13.2%), behavioural and psychiatric disorders (11.6%), neonatal critical care (11.4%), respiratory disorders (8.9%), non-critical neonatology (7.9%), and anaesthesia (6.5%). There were significantly fewer child-only studies (i.e., more mixed child and adult studies) over time (P = 0.0460). The proportion of RCTs to CCTs increased significantly over time (P<0.0001), as did the proportion of multicentre trials (P = 0.002). Significant increases over time were found in methodological quality (Jadad score) (P<0.0001), the proportion of double-blind studies (P<0.0001), and studies with adequate allocation concealment (P<0.0001). Additionally, we found an improvement in reporting over time: adequate description of withdrawals and losses to follow-up (P<0.0001), sample size calculations (P<0.0001), and intention-to-treat analysis (P<0.0001). However, many trials still do not describe their level of blinding, and allocation concealment was inadequately reported in the majority of studies across the entire time period. The proportion of studies with industry funding decreased slightly over time (P = 0.003), and these studies were more likely to report positive conclusions (P = 0.028). Conclusions/Significance The quantity and quality of pediatric controlled trials has increased over time; however, much work remains to be done, particularly in improving methodological issues around conduct and reporting of trials. PMID:20927344
Ebile, Akoh Walter; Ateudjieu, Jerome; Yakum, Martin Ndinakie; Djuidje, Marceline Ngounoue; Watcho, Pierre
2015-09-29
International guidelines recommend ethical and scientific quality standards for managing and reporting adverse events occurring during clinical trials to competent research ethics committees and regulatory authorities. The purpose of this study was to determine whether clinical trial protocols in Cameroon are developed in line with national requirements and international guidelines as far as detecting, reporting and investigating of adverse events is concerned. It was a documentary review of all approved clinical trial protocols that were submitted at the Cameroon National Ethics Committee for evaluation from 1997 through 2012. Data were extracted using a preconceived and validated grid. Protocol review process targeted the title, abstract, objectives, methodology, resources, and the chapter on safety. In total, 106 (4.9 %) clinical trial protocols were identified from 2173 protocols seen in the archive and 104 (4.8 %) included for review. Seventy six (73.1 %) trials did not include the surveillance of adverse events as part of their objective. A total of 91 (87.5 %) protocols did not budget for adverse event surveillance, 76 (73.1 %) did not have a data safety management board (DSMB), 11(10.6 %) included insurance for participants, 47 (45.2 %) did not include a case definition for serious adverse events, 33 (31.7 %) described procedures to detect adverse events, 33 (31.7 %) described procedure for reporting and 22 (21.2 %) described procedure for investigating adverse events. Most clinical trial protocols in Cameroon are developed to focus on benefits and pay little attention to harms. The development of national guidelines can improve the surveillance of adverse events in clinical trial research conducted in Cameroon. Adverse events surveillance tools and a budget are critical for an adequate planning for adverse event surveillance when developing trial protocols. Clinical trial protocols submitted in the Cameroon National Ethics Committee do not adequately plan to assess adverse events in clinical trial protocols. In order to improve on the safety of participants and marketed drug, there is a need to develop national guidelines for clinical trials by the government, and to improve evaluation procedures and monitoring of ongoing trials by the ethics committee.
Ambrosius, Walter T; Polonsky, Tamar S; Greenland, Philip; Goff, David C; Perdue, Letitia H; Fortmann, Stephen P; Margolis, Karen L; Pajewski, Nicholas M
2012-04-01
Although observational evidence has suggested that the measurement of coronary artery calcium (CAC) may improve risk stratification for cardiovascular events and thus help guide the use of lipid-lowering therapy, this contention has not been evaluated within the context of a randomized trial. The Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) trial is proposed as a randomized study in participants at low intermediate risk of future coronary heart disease (CHD) events to evaluate whether CAC testing leads to improved patient outcomes. To describe the challenges encountered in designing a prototypical screening trial and to examine the impact of uncertainty on power. The VIEW trial was designed as an effectiveness clinical trial to examine the benefit of CAC testing to guide therapy on a primary outcome consisting of a composite of nonfatal myocardial infarction, probable or definite angina with revascularization, resuscitated cardiac arrest, nonfatal stroke (not transient ischemic attack (TIA)), CHD death, stroke death, other atherosclerotic death, or other cardiovascular disease (CVD) death. Many critical choices were faced in designing the trial, including (1) the choice of primary outcome, (2) the choice of therapy, (3) the target population with corresponding ethical issues, (4) specifications of assumptions for sample size calculations, and (5) impact of uncertainty in these assumptions on power/sample size determination. We have proposed a sample size of 30,000 (800 events), which provides 92.7% power. Alternatively, sample sizes of 20,228 (539 events), 23,138 (617 events), and 27,078 (722 events) provide 80%, 85%, and 90% power. We have also allowed for uncertainty in our assumptions by computing average power integrated over specified prior distributions. This relaxation of specificity indicates a reduction in power, dropping to 89.9% (95% confidence interval (CI): 89.8-89.9) for a sample size of 30,000. Samples sizes of 20,228, 23,138, and 27,078 provide power of 78.0% (77.9-78.0), 82.5% (82.5-82.6), and 87.2% (87.2-87.3), respectively. These power estimates are dependent on form and parameters of the prior distributions. Despite the pressing need for a randomized trial to evaluate the utility of CAC testing, conduct of such a trial requires recruiting a large patient population, making efficiency of critical importance. The large sample size is primarily due to targeting a study population at relatively low risk of a CVD event. Our calculations also illustrate the importance of formally considering uncertainty in power calculations of large trials as standard power calculations may tend to overestimate power.
Ambrosius, Walter T.; Polonsky, Tamar S.; Greenland, Philip; Goff, David C.; Perdue, Letitia H.; Fortmann, Stephen P.; Margolis, Karen L.; Pajewski, Nicholas M.
2014-01-01
Background Although observational evidence has suggested that the measurement of CAC may improve risk stratification for cardiovascular events and thus help guide the use of lipid-lowering therapy, this contention has not been evaluated within the context of a randomized trial. The Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) trial is proposed as a randomized study in participants at low intermediate risk of future coronary heart disease (CHD) events to evaluate whether coronary artery calcium (CAC) testing leads to improved patient outcomes. Purpose To describe the challenges encountered in designing a prototypical screening trial and to examine the impact of uncertainty on power. Methods The VIEW trial was designed as an effectiveness clinical trial to examine the benefit of CAC testing to guide therapy on a primary outcome consisting of a composite of non-fatal myocardial infarction, probable or definite angina with revascularization, resuscitated cardiac arrest, non-fatal stroke (not transient ischemic attack (TIA)), CHD death, stroke death, other atherosclerotic death, or other cardiovascular disease (CVD) death. Many critical choices were faced in designing the trial, including: (1) the choice of primary outcome, (2) the choice of therapy, (3) the target population with corresponding ethical issues, (4) specifications of assumptions for sample size calculations, and (5) impact of uncertainty in these assumptions on power/sample size determination. Results We have proposed a sample size of 30,000 (800 events) which provides 92.7% power. Alternatively, sample sizes of 20,228 (539 events), 23,138 (617 events) and 27,078 (722 events) provide 80, 85, and 90% power. We have also allowed for uncertainty in our assumptions by computing average power integrated over specified prior distributions. This relaxation of specificity indicates a reduction in power, dropping to 89.9% (95% confidence interval (CI): 89.8 to 89.9) for a sample size of 30,000. Samples sizes of 20,228, 23,138, and 27,078 provide power of 78.0% (77.9 to 78.0), 82.5% (82.5 to 82.6), and 87.2% (87.2 to 87.3), respectively. Limitations These power estimates are dependent on form and parameters of the prior distributions. Conclusions Despite the pressing need for a randomized trial to evaluate the utility of CAC testing, conduct of such a trial requires recruiting a large patient population, making efficiency of critical importance. The large sample size is primarily due to targeting a study population at relatively low risk of a CVD event. Our calculations also illustrate the importance of formally considering uncertainty in power calculations of large trials as standard power calculations may tend to overestimate power. PMID:22333998
30 CFR 57.12008 - Insulation and fittings for power wires and cables.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulation and fittings for power wires and... NONMETAL MINES Electricity Surface and Underground § 57.12008 Insulation and fittings for power wires and cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical...
30 CFR 57.12008 - Insulation and fittings for power wires and cables.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulation and fittings for power wires and... NONMETAL MINES Electricity Surface and Underground § 57.12008 Insulation and fittings for power wires and cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical...
Povsic, Thomas J.; Vavalle, John P.; Aberle, Laura H.; Kasprzak, Jaroslaw D.; Cohen, Mauricio G.; Mehran, Roxana; Bode, Christoph; Buller, Christopher E.; Montalescot, Gilles; Cornel, Jan H.; Rynkiewicz, Andrzej; Ring, Michael E.; Zeymer, Uwe; Natarajan, Madhu; Delarche, Nicolas; Zelenkofske, Steven L.; Becker, Richard C.; Alexander, John H.
2013-01-01
Aims We sought to determine the degree of anticoagulation reversal required to mitigate bleeding, and assess the feasibility of using pegnivacogin to prevent ischaemic events in acute coronary syndrome (ACS) patients managed with an early invasive approach. REG1 consists of pegnivacogin, an RNA aptamer selective factor IXa inhibitor, and its complementary controlling agent, anivamersen. REG1 has not been studied in invasively managed patients with ACS nor has an optimal level of reversal allowing safe sheath removal been defined. Methods and results Non-ST-elevation ACS patients (n = 640) with planned early cardiac catheterization via femoral access were randomized 2:1:1:2:2 to pegnivacogin with 25, 50, 75, or 100% anivamersen reversal or heparin. The primary endpoint was total ACUITY bleeding through 30 days. Secondary endpoints included major bleeding and the composite of death, myocardial infarction, urgent target vessel revascularization, or recurrent ischaemia. Enrolment in the 25% reversal arm was suspended after 41 patients. Enrolment was stopped after three patients experienced allergic-like reactions. Bleeding occurred in 65, 34, 35, 30, and 31% of REG1 patients with 25, 50, 75, and 100% reversal and heparin. Major bleeding occurred in 20, 11, 8, 7, and 10% of patients. Ischaemic events occurred in 3.0 and 5.7% of REG1 and heparin patients, respectively. Conclusion At least 50% reversal is required to allow safe sheath removal after cardiac catheterization. REG1 appears a safe strategy to anticoagulate ACS patients managed invasively and warrants further investigation in adequately powered clinical trials of patients who require short-term high-intensity anticoagulation. Clinical Trials Registration: ClinicalTrials.gov NCT00932100. PMID:22859796
Cognitive-behavioural suicide prevention for male prisoners: a pilot randomized controlled trial.
Pratt, D; Tarrier, N; Dunn, G; Awenat, Y; Shaw, J; Ulph, F; Gooding, P
2015-12-01
Prisoners have an exceptional risk of suicide. Cognitive-behavioural therapy for suicidal behaviour has been shown to offer considerable potential, but has yet to be formally evaluated within prisons. This study investigated the feasibility of delivering and evaluating a novel, manualized cognitive-behavioural suicide prevention (CBSP) therapy for suicidal male prisoners. A pilot randomized controlled trial of CBSP in addition to treatment as usual (CBSP; n = 31) compared with treatment as usual (TAU; n = 31) alone was conducted in a male prison in England. The primary outcome was self-injurious behaviour occurring within the past 6 months. Secondary outcomes were dimensions of suicidal ideation, psychiatric symptomatology, personality dysfunction and psychological determinants of suicide, including depression and hopelessness. The trial was prospectively registered (number ISRCTN59909209). Relative to TAU, participants receiving CBSP therapy achieved a significantly greater reduction in suicidal behaviours with a moderate treatment effect [Cohen's d = -0.72, 95% confidence interval -1.71 to 0.09; baseline mean TAU: 1.39 (S.D. = 3.28) v. CBSP: 1.06 (S.D. = 2.10), 6 months mean TAU: 1.48 (S.D. = 3.23) v. CBSP: 0.58 (S.D. = 1.52)]. Significant improvements were achieved on measures of psychiatric symptomatology and personality dysfunction. Improvements on psychological determinants of suicide were non-significant. More than half of the participants in the CBSP group achieved a clinically significant recovery by the end of therapy, compared with a quarter of the TAU group. The delivery and evaluation of CBSP therapy within a prison is feasible. CBSP therapy offers significant promise in the prevention of prison suicide and an adequately powered randomized controlled trial is warranted.
Goodwin, Pamela J; Segal, Roanne J; Vallis, Michael; Ligibel, Jennifer A; Pond, Gregory R; Robidoux, André; Blackburn, George L; Findlay, Brian; Gralow, Julie R; Mukherjee, Som; Levine, Mark; Pritchard, Kathleen I
2014-07-20
Obesity is associated with poor outcomes in women with operable breast cancer. Lifestyle interventions (LIs) that help women reduce their weight may improve outcomes. We conducted a multicenter randomized trial comparing mail-based delivery of general health information alone or combined with a 24-month standardized, telephone-based LI that included diet (500 to 1,000 kcal per day deficit) and physical activity (150 to 200 minutes of moderate-intensity physical activity per week) goals to achieve weight loss (up to 10%). Women receiving adjuvant letrozole for T1-3N0-3M0 breast cancer with a body mass index (BMI) ≥ 24 kg/m(2) were eligible. Weight was measured in the clinic, and self-report physical activity, quality-of-life (QOL), and diet questionnaires were completed. The primary outcome was disease-free survival. Accrual was terminated at 338 of 2,150 planned patients because of loss of funding. Mean weight loss was significantly (P < .001) greater in the LI arm versus the comparison arm (4.3 v 0.6 kg or 5.3% v 0.7% at 6 months and 3.1 v 0.3 kg or 3.6% v 0.4% at 24 months) and occurred consistently across strata (BMI 24 to < 30 v ≥ 30 kg/m(2); prior v no prior adjuvant chemotherapy). Weight loss was greatest in those with higher baseline levels of moderate-intensity physical activity or improvement in QOL. Hospitalization rates and medical events were similar. A telephone-based LI led to significant weight loss that was still evident at 24 months, without adverse effects on QOL, hospitalizations, or medical events. Adequately powered randomized trials with cancer end points are needed. © 2014 by American Society of Clinical Oncology.
Feasibility of a Trial on Improvisational Music Therapy for Children with Autism Spectrum Disorder.
Geretsegger, Monika; Holck, Ulla; Bieleninik, Łucja; Gold, Christian
2016-01-01
To conduct generalizable, rigorously designed, adequately powered trials investigating music therapy and other complex interventions, it is essential that study procedures are feasible and acceptable for participants. To date, only limited evidence on feasibility of trial designs and strategies to facilitate study implementation is available in the music therapy literature. Using data from a subsample of a multi-center RCT on improvisational music therapy (IMT) for autism spectrum disorder (ASD), this study aims to evaluate feasibility of study procedures, evaluate safety, document concomitant treatment, and report consistency of individuals' trends over time in chosen outcome measures. Children with ASD aged between 4 years, 0 months, and 6 years, 11 months, were randomly assigned to one of three conditions: one (low intensity) vs. three weekly IMT sessions (high intensity) for five months vs. standard care. Feasibility was evaluated by examining recruitment, implementation of study conditions, assessment procedures, blinding, and retention; we also evaluated safety, concomitant treatment, and consistency of changes in standardized scales completed by blinded assessors and parents before and 5 months after randomization. Within this subsample (n = 15), recruitment rates, session attendance in the high-intensity condition, and consistency between outcome measures were lower than expected. Session attendance in the low-intensity and control conditions, treatment fidelity, measurement completion, blinding, retention, and safety met a priori thresholds for feasibility. By discussing strategies to improve recruitment and to minimize potential burden on study participants, referrers, and researchers, this study helps build knowledge about designing and implementing trials successfully. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
van Ochten, John; Luijsterburg, Pim A J; van Middelkoop, Marienke; Koes, Bart W; Bierma-Zeinstra, Sita M A
2010-01-01
Objective To summarise the effectiveness of adding supervised exercises to conventional treatment compared with conventional treatment alone in patients with acute lateral ankle sprains. Design Systematic review. Data sources Medline, Embase, Cochrane Central Register of Controlled Trials, Cinahl, and reference screening. Study selection Included studies were randomised controlled trials, quasi-randomised controlled trials, or clinical trials. Patients were adolescents or adults with an acute lateral ankle sprain. The treatment options were conventional treatment alone or conventional treatment combined with supervised exercises. Two reviewers independently assessed the risk of bias, and one reviewer extracted data. Because of clinical heterogeneity we analysed the data using a best evidence synthesis. Follow-up was classified as short term (up to two weeks), intermediate (two weeks to three months), and long term (more than three months). Results 11 studies were included. There was limited to moderate evidence to suggest that the addition of supervised exercises to conventional treatment leads to faster and better recovery and a faster return to sport at short term follow-up than conventional treatment alone. In specific populations (athletes, soldiers, and patients with severe injuries) this evidence was restricted to a faster return to work and sport only. There was no strong evidence of effectiveness for any of the outcome measures. Most of the included studies had a high risk of bias, with few having adequate statistical power to detect clinically relevant differences. Conclusion Additional supervised exercises compared with conventional treatment alone have some benefit for recovery and return to sport in patients with ankle sprain, though the evidence is limited or moderate and many studies are subject to bias. PMID:20978065
Djulbegovic, Benjamin; Cantor, Alan; Clarke, Mike
2003-01-01
Previous research has identified methodological problems in the design and conduct of randomized trials that could, if left unaddressed, lead to biased results. In this report we discuss one such problem, inadequate control intervention, and argue that it can be by far the most important design characteristic of randomized trials in overestimating the effect of new treatments. Current guidelines for the design and reporting of randomized trials, such as the Consolidated Standards of Reporting Trials (CONSORT) statement, do not address the choice of the comparator intervention. We argue that an adequate control intervention can be selected if people designing a trial explicitly take into consideration the ethical principle of equipoise, also known as "the uncertainty principle."
Topical cyclosporine for atopic keratoconjunctivitis.
González-López, Julio J; López-Alcalde, Jesús; Morcillo Laiz, Rafael; Fernández Buenaga, Roberto; Rebolleda Fernández, Gema
2012-09-12
Atopic keratoconjunctivitis (AKC) is a chronic ocular surface non-infectious inflammatory condition that atopic dermatitis patients may suffer at any time point in the course of their dermatologic disease and is independent of its degree of severity. AKC is usually not self resolving and it poses a higher risk of corneal injuries and severe sequelae. Management of AKC should prevent or treat corneal damage. Although topical corticosteroids remain the standard treatment for patients with AKC, prolonged use may lead to complications. Topical cyclosporine A (CsA) may improve AKC signs and symptoms, and be used as a corticosteroid sparing agent. To determine the efficacy and gather evidence on safety from randomised controlled trials (RCTs) of topical CsA in patients with AKC. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 6), MEDLINE (January 1946 to July 2012), EMBASE (January 1980 to July 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to July 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), the IFPMA Clinical Trials Portal (http://clinicaltrials.ifpma.org/no_cache/en/myportal/index.htm) and Web of Science Conference Proceedings Citation Index- Science (CPCI-S). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 9 July 2012. We also handsearched the following conference proceedings: American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, International Council of Opthalmology and Societas Ophthalmologica Europaea from 2005 to July 2011. We included randomised controlled trials only. Two review authors independently extracted data. Due to the small number of studies and the diversity of outcome measures, interventions and participants, we presented results narratively. We found three RCTs with a total of 58 participants that were eligible for inclusion. There was significant variability between the trials in interventions, methodology and outcome measures and therefore we did not perform meta-analysis.One study reported on the use of 2% CsA in maize oil and two on the use of a commercial emulsion of 0.05% CsA. Of these three studies, one showed a beneficial effect of topical CsA in controlling signs and symptoms of AKC, one in controlling signs of AKC and one did not show evidence of an improvement. Only two studies analysed the effect of topical CsA in reducing topical steroid use; one showed a significant reduction in topical steroid use with CsA, but the other did not show evidence of this improvement. No serious adverse events were reported in the trials. This systematic review highlights the relative scarcity of controlled clinical trials assessing the efficacy of topical CsA therapy in AKC and suggests that evidence on the efficacy and safety of topical CsA treatment in patients with CsA remains limited. However, the data suggest that topical CsA may provide clinical and symptomatic relief in AKC and may help to reduce topical steroid use in patients with steroid-dependent or steroid-resistant AKC. No serious adverse events were reported. Reported adverse events in patients treated with topical CsA include intense stinging and eyelid skin maceration. One patient in the placebo group developed a severe allergic response to maize antigens. However, the total number of patients in the trials was too small to assess the safety of this treatment.Additional well-designed and powered RCTs of topical CsA in AKC are needed. Ideal study designs should include adequate randomisation and concealment of allocation; masking of participants, personnel and outcome assessors; adequate follow-up periods and minimisation of attrition bias; and comparison groups with similar clinical and epidemiologic characteristics. Samples should be large enough to provide sufficient statistical power to assess the safety of CsA and to detect clinically relevant treatment effect sizes of the primary outcomes. Analyses should be appropriate to the study's design and outcome measures. Moreover, standardisation of outcome measures and follow-up periods across studies would be beneficial to maximise study comparability.
Cannabinoids in treatment-resistant epilepsy: A review.
O'Connell, Brooke K; Gloss, David; Devinsky, Orrin
2017-05-01
Treatment-resistant epilepsy (TRE) affects 30% of epilepsy patients and is associated with severe morbidity and increased mortality. Cannabis-based therapies have been used to treat epilepsy for millennia, but only in the last few years have we begun to collect data from adequately powered placebo-controlled, randomized trials (RCTs) with cannabidiol (CBD), a cannabis derivative. Previously, information was limited to case reports, small series, and surveys reporting on the use of CBD and diverse medical marijuana (MMJ) preparations containing: tetrahydrocannabinol (THC), CBD, and many other cannabinoids in differing combinations. These RCTs have studied the safety and explored the potential efficacy of CBD use in children with Dravet Syndrome (DS) and Lennox-Gastaut Syndrome (LGS). The role of the placebo response is of paramount importance in studying medical cannabis products given the intense social and traditional media attention, as well as the strong beliefs held by many parents and patients that a natural product is safer and more effective than FDA-approved pharmaceutical agents. We lack valid data on the safety, efficacy, and dosing of artisanal preparations available from dispensaries in the 25 states and District of Columbia with MMJ programs and online sources of CBD and other cannabinoids. On the other hand, open-label studies with 100mg/ml CBD (Epidiolex®, GW Pharmaceuticals) have provided additional evidence of its efficacy along with an adequate safety profile (including certain drug interactions) in children and young adults with a spectrum of TREs. Further, Phase 3 RCTs with Epidiolex support efficacy and adequate safety profiles for children with DS and LGS at doses of 10- and 20-mg/kg/day. This article is part of a Special Issue titled "Cannabinoids and Epilepsy". Copyright © 2016 Elsevier Inc. All rights reserved.
Power Plant Water Intake Assessment.
ERIC Educational Resources Information Center
Zeitoun, Ibrahim H.; And Others
1980-01-01
In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)
Full-Tree Skidding Favors Black Spruce Reproduction Under Certain Peatland Conditions
William F. Johnston
1980-01-01
Two trials on different sites indicate that clearcut black spruce reproduces well after full-tree skidding only on nonbrushy sites that have fairly abundant sphagnum seedbeds and adequate natural seeding.
Current treatment of juvenile rheumatoid arthritis.
Ilowite, Norman T
2002-01-01
Prognostic factors in juvenile rheumatoid arthritis (JRA) include polyarticular onset, polyarticular disease course, and rheumatoid factor positivity; in the systemic onset subtype, persistence of systemic features at 6 months after onset confers a worse prognosis. Timely diagnosis and appropriate aggressive treatment of patients with poor prognostic features improve quality of life and outcome. After nonsteroidal anti-inflammatory drugs, methotrexate is the most commonly used second-line agent. However, approximately one third of patients do not respond to methotrexate adequately. Randomized, placebo-controlled, clinical trials in patients with JRA are few, but one such trial with the tumor necrosis factor inhibitor etanercept shows that this drug is effective and well-tolerated. Other recently approved agents for rheumatoid arthritis, including infliximab, leflunomide, celecoxib, and rofecoxib, have not been adequately studied in pediatric patients, and the role of these agents in children with JRA remains to be determined.
Yang, Lei; Chen, Shouming; Yang, Di; Li, Jiajin; Wu, Taixiang; Zuo, Yunxia
2018-05-15
To learn about the overall quality of clinical anaesthesia study protocols from the Chinese Clinical Trials Registry and to discuss the way to improve study protocol quality. We defined completeness of each sub-item in SPIRIT as N/A (not applicable) or with a score of 0, 1, or 2. For each protocol, we calculated the proportion of adequately reported items (score = 2 and N/A) and unreported items (score = 0). Protocol quality was determined according to the proportion of reported items, with values >50% indicating high quality. Protocol quality was determined according to the proportion of reported items. For each sub-item in SPIRIT, we calculated the adequately reported rate (percentage of all protocols with score 2 and NA on one sub-item) as well as the unreported rate (percentage of all protocols with score 0 on one sub-item). Total 126 study protocols were available for assessment. Among these, 88.1% were assessed as being of low quality. By comparison, the percentage of low-quality protocols was 88.9% after the publication of the SPIRIT statement. Among the 51 SPIRIT sub-items, 18 sub-items had an unreported rate above 90% while 16 had a higher adequately reported rate than an unreported rate. The overall quality of clinical anaesthesia study protocols registered in the ChiCTR was poor. A mandatory protocol upload and self-check based on the SPIRIT statement during the trial registration process may improve protocol quality in the future.
Roth, M Y; Ilani, N; Wang, C; Page, S T; Bremner, W J; Swerdloff, R S; Dart, C; Sitruk-Ware, R; Kumar, N; Blithe, D; Amory, J K
2013-11-01
Development of a male hormonal contraceptive has been challenging ascribable to the failure to adequately suppress spermatogenesis in 5-10% of men. Methods to identify incomplete suppressors early in treatment might identify men most responsive to male hormonal contraceptives. We hypothesized that serum hormone and gonadotropin concentrations after 4 weeks of transdermal treatment with testosterone and Nestorone in a contraceptive trial would be associated with suppression of sperm concentrations to <1 million/mL after 24 weeks. Indeed, luteinizing hormone or follicle-stimulating hormone concentrations greater than 1 IU/L after 4 weeks of transdermal testosterone/nestorone treatment were 97% sensitive for predicting failure to suppress spermatogenesis after 24 weeks of treatment. Serum nestorone concentrations were significantly associated with suppression, but serum testosterone concentrations were not. Early suppression of gonadotropins is associated with, but does not ensure, adequate suppression of spermatogenesis. This information may allow for rapid identification of non-responders in male hormonal contraceptive trials. © 2013 American Society of Andrology and European Academy of Andrology.
Roberts, J; Waddy, S; Kaufmann, P
2012-01-01
It is commonly accepted that inefficient recruitment and inadequate retention continue to threaten the completion of clinical trials intended to reduce the public health burden of neurological disease. This article will discuss the scientific, economic, and ethical implications of failure to recruit and retain adequate samples in clinical trials, including the consequences of failing to recruit adequately diverse samples. We will also discuss the more common challenges and barriers to efficient and effective recruitment and retention, and the impact these have on successful clinical trial planning. We will explain the newly established efforts within National Institute of Neurological Disorders and Stroke (NINDS) to monitor recruitment and retention with well-defined metrics and implementation of grant awards that include feasibility milestones for continued funding. Finally, we will describe our efforts to address some of the common challenges to recruitment and retention through assistance to investigators and coordinators with evidence-based support, tools, and resources for planning and strategizing recruitment and retention as well as a trans-NIH effort to improve awareness of clinical research in the general public. PMID:23230460
Inappropriate oral formulations and information in paediatric trials.
Pandit, Sreenivas; Shah, Utpal; Kirby, Daniel Jon; Nunn, Tony; Tuleu, Catherine
2010-09-01
Previously, quality of formulations information provided for oral medications used in paediatric clinical trials published in 10 highly cited journals between 2002 and 2004 raised concerns. This short report explores if there was any subsequent improvement on how the formulations used in trials involving children <12 years reported in the same journals. Studies published between 2004 and 2008 were hand-searched and classified as containing adequate, some or no formulation information. Those involving solid dosage forms were further analysed. Only 31% (44/140) of publications provided adequate information, 5% less compared to 2002-2004 (28/76). There was a significant 12% rise (p<0.05) of no formulation information at all (37/140) and in tablets/capsules use (53/140), of which 3/4 gave no administration details, even for those under 6 years old, but a 12% decline in suitable paediatric formulations use (52/140 compared to 37/76). Contrary to expectations, overall quality of formulation information reported markedly deteriorated, jeopardising validity of clinical outcomes. The situation may reflect continued lack of awareness among investigators and other stakeholders of the importance of using suitable age-appropriate formulations.
Geense, Wytske W; van Gaal, Betsie Gi; Knoll, Jacqueline L; Cornelissen, Elisabeth Am; Schoonhoven, Lisette; Kok, Gerjo
2016-01-13
The care for children with a chronic kidney disease (CKD) is complex. Parents of these children may experience high levels of stress in managing their child's disease, potentially leading to negative effects on their child's health outcomes. Although the experienced problems are well known, adequate (online) support for these parents is lacking. The objective of the study is to describe the systematic development of an online support program for parents of children with CKD, and how this program will be evaluated. Intervention Mapping (IM) was used for the development of the program. After conducting a needs assessment, defining program objectives, searching for theories, and selecting practical applications, the online program e-Powered Parents was developed. e-Powered Parents consist of three parts: (1) an informative part with information about CKD and treatments, (2) an interactive part where parents can communicate with other parents and health care professionals by chat, private messages, and a forum, and (3) a training platform consisting of four modules: Managing stress, Setting limits, Communication, and Coping with emotions. In a feasibility study, the potential effectiveness and effect size of e-Powered Parents will be evaluated using an explorative randomized controlled trial with parents of 120 families. The outcomes will be the child's quality of life, parental stress and fatigue, self-efficacy in the communication with health care professionals, and family management. A process evaluation will provide insight in parents' experiences, including their experienced level of support. Study results are expected to be published in the summer of 2016. Although the development of e-Powered Parents using IM was time-consuming, IM has been a useful protocol. IM provided us with a systematic framework for structuring the development process. The participatory planning group was valuable as well; knowledge, experiences, and visions were shared, ensuring us that parents and health care professionals support the program. Dutch Trial Registration: NTR4808; www.trialregister.nl (Archived by WebCite at http://www.webcitation.org/6cfAYHcYb).
Cunanan, Kristen M; Carlin, Bradley P; Peterson, Kevin A
2016-12-01
Many clinical trial designs are impractical for community-based clinical intervention trials. Stepped wedge trial designs provide practical advantages, but few descriptions exist of their clinical implementational features, statistical design efficiencies, and limitations. Enhance efficiency of stepped wedge trial designs by evaluating the impact of design characteristics on statistical power for the British Columbia Telehealth Trial. The British Columbia Telehealth Trial is a community-based, cluster-randomized, controlled clinical trial in rural and urban British Columbia. To determine the effect of an Internet-based telehealth intervention on healthcare utilization, 1000 subjects with an existing diagnosis of congestive heart failure or type 2 diabetes will be enrolled from 50 clinical practices. Hospital utilization is measured using a composite of disease-specific hospital admissions and emergency visits. The intervention comprises online telehealth data collection and counseling provided to support a disease-specific action plan developed by the primary care provider. The planned intervention is sequentially introduced across all participating practices. We adopt a fully Bayesian, Markov chain Monte Carlo-driven statistical approach, wherein we use simulation to determine the effect of cluster size, sample size, and crossover interval choice on type I error and power to evaluate differences in hospital utilization. For our Bayesian stepped wedge trial design, simulations suggest moderate decreases in power when crossover intervals from control to intervention are reduced from every 3 to 2 weeks, and dramatic decreases in power as the numbers of clusters decrease. Power and type I error performance were not notably affected by the addition of nonzero cluster effects or a temporal trend in hospitalization intensity. Stepped wedge trial designs that intervene in small clusters across longer periods can provide enhanced power to evaluate comparative effectiveness, while offering practical implementation advantages in geographic stratification, temporal change, use of existing data, and resource distribution. Current population estimates were used; however, models may not reflect actual event rates during the trial. In addition, temporal or spatial heterogeneity can bias treatment effect estimates. © The Author(s) 2016.
Bruno, Antonio; Pandolfo, Gianluca; Crucitti, Manuela; Lorusso, Simona; Zoccali, Rocco Antonio; Muscatello, Maria Rosaria Anna
This was the first 12-week, open-label, uncontrolled trial aimed at exploring the efficacy of acetyl-L-carnitine (ALC) add-on pharmacotherapy on clinical symptoms and cognitive functioning in 15 schizophrenia patients with suboptimal clinical response despite receiving clozapine (CLZ) monotherapy at the highest tolerated dosage. After clinical (Positive and Negative Symptoms Scale [PANSS]) and neuropsychological (Wisconsin Card Sorting Test, Stroop Color-Word Test, Verbal Fluency Test) assessments, patients received 1 g/d of ALC for 12 weeks. A final sample of 9 subjects completed the study. Acetyl-L-carnitine augmentation of CLZ significantly reduced only PANSS domains "positive" (P = 0.049); at end point, only 2 subjects (22.2% of the completers) reached a minimal improvement (25% reduction in PANSS total score). No significant differences emerged in cognitive performances at the end of the study; effect sizes were small in each explored cognitive dimension. The findings provide preliminary evidence that ALC added to ongoing CLZ treatment appeared to be ineffective to improve symptoms in schizophrenia patients who have failed to respond sufficiently to CLZ. Further trials with adequately powered methodology are needed to identify which augmentation strategies are more effective in schizophrenia patients showing a suboptimal response to CLZ.
Male Infertility during Antihypertensive Therapy: Are We Addressing Correctly The Problem?
Laganà, Antonio Simone; Vitale, Salvatore Giovanni; Iaconianni, Paola; Gatti, Simona; Padula, Francesco
2016-01-01
Male fertility significantly decreased in the last 50 years, as showed in several studies reporting a reduction of sperm counts per ml in the seminal fluid. Several "acute" pharmacological treatments, as antibiotics, could cause subclinical and temporary reduction of male fertility; conversely, long-term medical treatment may severely affect male fertility, although this effect could be considered transient in most of the cases. Thus, nowadays, several long-term pharmacological treatments may represent a clinical challenge. The association between several kind of antihypertensive drugs and reduction of male fertility has been showed in the mouse model, although the modification(s) which may alter this fine-regulated machinery are still far to be elucidated. Furthermore, well-designed observational studies and randomized controlled trials are needed to accurately define this association in human model, meaning a narrative overview synthesizing the findings of literature retrieved from searches of computerized databases. We strongly solicit future human studies (both observational and randomized clinical trials) on large cohorts with adequate statistical power which may clarify this possible association and the effects (reversible or permanent) of each drug. Furthermore, we suggest a close collaboration between general practitioners, cardiologists, and andrologists in order to choose the most appropriate antihypertensive therapy considering also patient's reproductive desire and possible risk for his fertility.
Ashton, Lee M; Morgan, Philip J; Hutchesson, Melinda J; Rollo, Megan E; Young, Myles D; Collins, Clare E
2015-12-01
To investigate the effectiveness of Smoking, Nutrition, Alcohol, Physical activity and Obesity (SNAPO) interventions in young men exclusively. The secondary aim was to evaluate the recruitment, retention and engagement strategies. A search with no date restrictions was conducted across seven databases. Randomized controlled trials recruiting young men only (aged 18-35 years) into interventions targeting any SNAPO risk factors were included. Ten studies were included (two nutrition, six alcohol use, two targeting multiple SNAPO risk factors). Six studies (two nutrition, three alcohol use and one targeting multiple SNAPO risk factors) demonstrated significant positive short-term intervention effects, but impact was either not assessed beyond the intervention (n=3), had short-term follow-up (≤6 months) (n=2) or not sustained beyond six months (n=1). Overall, a high risk of bias was identified across studies. Only one study undertook a power calculation and recruited the required sample size. Adequate retention was achieved in three studies. Effectiveness of engagement strategies was not reported in any studies. Despite preliminary evidence of short-term effectiveness of SNAPO interventions in young men, few studies characterized by a high risk of bias were identified. High quality SNAPO interventions for young men are warranted. Copyright © 2015 Elsevier Inc. All rights reserved.
Subthreshold muscle twitches dissociate oscillatory neural signatures of conflicts from errors.
Cohen, Michael X; van Gaal, Simon
2014-02-01
We investigated the neural systems underlying conflict detection and error monitoring during rapid online error correction/monitoring mechanisms. We combined data from four separate cognitive tasks and 64 subjects in which EEG and EMG (muscle activity from the thumb used to respond) were recorded. In typical neuroscience experiments, behavioral responses are classified as "error" or "correct"; however, closer inspection of our data revealed that correct responses were often accompanied by "partial errors" - a muscle twitch of the incorrect hand ("mixed correct trials," ~13% of the trials). We found that these muscle twitches dissociated conflicts from errors in time-frequency domain analyses of EEG data. In particular, both mixed-correct trials and full error trials were associated with enhanced theta-band power (4-9Hz) compared to correct trials. However, full errors were additionally associated with power and frontal-parietal synchrony in the delta band. Single-trial robust multiple regression analyses revealed a significant modulation of theta power as a function of partial error correction time, thus linking trial-to-trial fluctuations in power to conflict. Furthermore, single-trial correlation analyses revealed a qualitative dissociation between conflict and error processing, such that mixed correct trials were associated with positive theta-RT correlations whereas full error trials were associated with negative delta-RT correlations. These findings shed new light on the local and global network mechanisms of conflict monitoring and error detection, and their relationship to online action adjustment. © 2013.
Sackley, Catherine M; Smith, Christina H; Rick, Caroline E; Brady, Marian C; Ives, Natalie; Patel, Smitaa; Woolley, Rebecca; Dowling, Francis; Patel, Ramilla; Roberts, Helen; Jowett, Sue; Wheatley, Keith; Kelly, Debbie; Sands, Gina; Clarke, Carl E
2018-01-01
Speech-related problems are common in Parkinson's disease (PD), but there is little evidence for the effectiveness of standard speech and language therapy (SLT) or Lee Silverman Voice Treatment (LSVT LOUD®). The PD COMM pilot was a three-arm, assessor-blinded, randomised controlled trial (RCT) of LSVT LOUD®, SLT and no intervention (1:1:1 ratio) to assess the feasibility and to inform the design of a full-scale RCT. Non-demented patients with idiopathic PD and speech problems and no SLT for speech problems in the past 2 years were eligible. LSVT LOUD® is a standardised regime (16 sessions over 4 weeks). SLT comprised individualised content per local practice (typically weekly sessions for 6-8 weeks). Outcomes included recruitment and retention, treatment adherence, and data completeness. Outcome data collected at baseline, 3, 6, and 12 months included patient-reported voice and quality of life measures, resource use, and assessor-rated speech recordings. Eighty-nine patients were randomised with 90% in the therapy groups and 100% in the control group completing the trial. The response rate for Voice Handicap Index (VHI) in each arm was ≥ 90% at all time-points. VHI was highly correlated with the other speech-related outcome measures. There was a trend to improvement in VHI with LSVT LOUD® (difference at 3 months compared with control: - 12.5 points; 95% CI - 26.2, 1.2) and SLT (difference at 3 months compared with control: - 9.8 points; 95% CI - 23.2, 3.7) which needs to be confirmed in an adequately powered trial. Randomisation to a three-arm trial of speech therapy including a no intervention control is feasible and acceptable. Compliance with both interventions was good. VHI and other patient-reported outcomes were relevant measures and provided data to inform the sample size for a substantive trial. International Standard Randomised Controlled Trial Number Register: ISRCTN75223808. registered 22 March 2012.
How to Evaluate Phase Differences between Trial Groups in Ongoing Electrophysiological Signals
VanRullen, Rufin
2016-01-01
A growing number of studies endeavor to reveal periodicities in sensory and cognitive functions, by comparing the distribution of ongoing (pre-stimulus) oscillatory phases between two (or more) trial groups reflecting distinct experimental outcomes. A systematic relation between the phase of spontaneous electrophysiological signals, before a stimulus is even presented, and the eventual result of sensory or cognitive processing for that stimulus, would be indicative of an intrinsic periodicity in the underlying neural process. Prior studies of phase-dependent perception have used a variety of analytical methods to measure and evaluate phase differences, and there is currently no established standard practice in this field. The present report intends to remediate this need, by systematically comparing the statistical power of various measures of “phase opposition” between two trial groups, in a number of real and simulated experimental situations. Seven measures were evaluated: one parametric test (circular Watson-Williams test), and three distinct measures of phase opposition (phase bifurcation index, phase opposition sum, and phase opposition product) combined with two procedures for non-parametric statistical testing (permutation, or a combination of z-score and permutation). While these are obviously not the only existing or conceivable measures, they have all been used in recent studies. All tested methods performed adequately on a previously published dataset (Busch et al., 2009). On a variety of artificially constructed datasets, no single measure was found to surpass all others, but instead the suitability of each measure was contingent on several experimental factors: the time, frequency, and depth of oscillatory phase modulation; the absolute and relative amplitudes of post-stimulus event-related potentials for the two trial groups; the absolute and relative trial numbers for the two groups; and the number of permutations used for non-parametric testing. The concurrent use of two phase opposition measures, the parametric Watson-Williams test and a non-parametric test based on summing inter-trial coherence values for the two trial groups, appears to provide the most satisfactory outcome in all situations tested. Matlab code is provided to automatically compute these phase opposition measures. PMID:27683543
Olivera, P; Sandborn, W J; Panés, J; Baumann, C; D'Haens, G; Vermeire, S; Danese, S; Peyrin-Biroulet, L
2018-03-01
Several novel compounds are being developed for inflammatory bowel diseases (IBD). In addition, biosimilar drugs are being approved. An increasing number of head-to-head, superiority and non-inferiority trials in patients with IBD are expected in the future. The clinical relevance of the magnitude of the effect size is often debated. To better understand physicians' perspectives on the clinical meaningfulness of IBD trial results. We conducted an online survey among all IOIBD (International Organization for the Study of Inflammatory Bowel Diseases) members, asking their opinion on the clinical relevance of the results of IBD trials. Forty-six IOIBD members responded to the survey (52.3%). In biologic-naïve ulcerative colitis (UC) and Crohn's disease (CD) patients, most of the participants considered a 15% difference with placebo for clinical remission and endoscopic remission to be clinically relevant. In head-to-head trials, most of participants considerer a 10% difference between groups for clinical remission and endoscopic remission to be clinically relevant. Half of respondents considered 10% to be an adequate margin in non-inferiority trials. In bioequivalence studies, most of the participants considered adequate a ± 5% difference between a biosimilar and the originator for pharmacokinetic parameters, efficacy, safety and immunogenicity. Regarding safety, the difference between two drugs considered clinically relevant varied from 1% to 5%, depending on the type of adverse event. This is the first survey exploring how physicians perceive IBD trial results, providing an estimation of the magnitude of the difference between treatment arms that may directly influence clinical practice. © 2018 John Wiley & Sons Ltd.
Ni, Weimin; Shi, Xiang'en
2018-06-23
Craniopharyngiomas (CPs) and their treatment are associated with hypothalamic damage that causes hypothalamic obesity (HO) in 30-70% of cases. Thus, there is ongoing research regarding tangible solutions for HO, as these patients have unrelenting resistance to basic weight-loss interventions. This review aims to summarize the interventions that are currently used to treat CP-related HO (CP-HO), including pharmacotherapy and bariatric surgery. The Cochrane Library, EMBASE, and PubMed databases were searched up to June 2017 for relevant reports. Two reviewers conducted independent evaluations of the identified studies. Eighteen publications were included in the systematic review, with three reports describing pharmacotherapy in randomized controlled trials and 15 reports describing bariatric surgery. Although several studies described effective interventions for treating CP-HO, the evidence base was limited by its low quality and our inability to perform a meta-analysis, which was related to a lack of adequate or integrated data. Octreotide appears to be a preferred treatment for CP-HO patients, based on currently limited data. Gastric bypass surgery may also be suitable for select CP-HO patients, based on a review of various procedures in this setting. Microsurgical preservation of the hypothalamic structures is mandatory to decrease CP-HO-related morbidity and mortality. Further studies with adequate analytical power and sufficient follow-up are needed to identify effective strategies for CP-HO treatment. Copyright © 2018 Elsevier Inc. All rights reserved.
Yeh, Hsin-Chieh; Clark, Jeanne M.; Emmons, Karen M.; Moore, Renee H.; Bennett, Gary G; Warner, Erica T.; Sarwer, Davis B.; Jerome, Gerald J; Miller, Edgar R; Volger, Sheri; Louis, Thomas A.; Wells, Barbara; Wadden, Thomas A.; Colditz, Graham A.; Appel, Lawrence J.
2011-01-01
Background The National Heart, Lung, and Blood Institute (NHLBI) funded three institutions to conduct effectiveness trials of weight loss interventions in primary care settings. Unlike traditional multi-center clinical trials, each study was established as an independent trial with a distinct protocol. Still, efforts were made to coordinate and standardize several aspects of the trials. The three trials formed a collaborative group, the “Practice Based Opportunities for Weight Reduction (POWER) Trials Collaborative Research Group.” Purpose We describe the common and distinct features of the three trials, the key characteristics of the collaborative group, and the lessons learned from this novel organizational approach. Methods The Collaborative Research Group consists of three individual studies: “Be Fit, Be Well“(Washington University in St. Louis/Harvard University), “POWER Hopkins” (Johns Hopkins), and “POWER-UP” (University of Pennsylvania). There are a total of 15 participating clinics with ~1,100 participants. The common primary outcome is change in weight at 24 months of follow-up, but each protocol has trial-specific elements including different interventions and different secondary outcomes. A Resource Coordinating Unit at Johns Hopkins provides administrative support. Results The Collaborative Research Group established common components to facilitate potential cross-site comparisons. The main advantage of this approach is to develop and evaluate several interventions, when there is insufficient evidence to test one or two approaches, as would be done in a traditional multi-center trial. Limitations The challenges of the organizational design include the complex decision making process, the extent of potential data pooling, time intensive efforts to standardize reports, and the additional responsibilities of the DSMB to monitor three distinct protocols. Conclusions The POWER Trials Collaborative Research Group is a case study of an alternative organizational model to conduct independent, yet coordinated trials. Such a model is increasingly being used in NHLBI supported trials , especially given the interest in comparative effectiveness research. Nevertheless, the ultimate utility of this model will not be fully understood until the trials are completed. PMID:20573639
Importance of hard coal in electricity generation in Poland
NASA Astrophysics Data System (ADS)
Plewa, Franciszek; Strozik, Grzegorz
2017-11-01
Polish energy sector is facing a number of challenges, in particular as regards the reconstruction of production potential, diversification of energy sources, environmental issues, adequate fuels supplies and other. Mandatory implementation of Europe 2020 strategy in terms of “3x20” targets (20% reduction of greenhouse gases, 20% of energy from renewable sources, and 20% increase of efficiency in energy production) requires fast decision, which have to be coordinated with energetic safety issues, increasing demands for electric energy, and other factors. In Poland almost 80% of power is installed in coal fired power plants and energy from hard coals is relatively less expensive than from other sources, especially renewable. The most of renewable energy sources power plants are unable to generate power in amounts which can be competitive with coal fires power stations and are highly expensive, what leads o high prices of electric energy. Alternatively, new generation of coal fired coal power plants is able to significantly increase efficiency, reduce carbon dioxide emission, and generate less expensive electric power in amounts adequate to the demands of a country.
Hosaka, Ryosuke; Nakajima, Toshi; Aihara, Kazuyuki; Yamaguchi, Yoko; Mushiake, Hajime
2016-08-01
The medial motor areas play crucial but flexible roles in the temporal organizations of multiple movements. The beta oscillation of local field potentials is the predominant oscillatory activity in the motor areas, but the manner in which increases and decreases in beta power contribute to updating of multiple action plans is not yet fully understood. In the present study, beta and high-gamma activities in the supplementary motor area (SMA) and pre-SMA of monkeys were analyzed during performance of a bimanual motor sequence task that required updating and maintenance of the memory of action sequences. Beta power was attenuated during early delay periods of updating trials but was increased during maintenance trials, while there was a reciprocal increase in high-gamma power during updating trials. Moreover, transient attenuation of beta power during maintenance trials resulted in the erroneous selection of an action sequence. Therefore, it was concluded that the suppression of beta power during the early delay period reflects volatility of neural representation of the action sequence. This neural representation would be properly updated to the appropriate instructed action sequence via increases in high-gamma power in updating trials whereas it would be erroneously updated without the appropriate updating signal in maintenance trials. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Coakley, Sarah L; Passfield, Louis
2018-06-01
Time-to-exhaustion (TTE) trials are used in a laboratory setting to measure endurance performance. However, there is some concern with their ecological validity compared with time-trials (TT). Consequently, we aimed to compare cycling performance in TTE and TT where the duration of the trials was matched. Seventeen trained male cyclists completed three TTE trials at 80, 100 and 105% of maximal aerobic power (MAP). On a subsequent visit they performed three TT over the same duration as the TTE. Participants were blinded to elapsed time, power output, cadence and heart rate (HR). Average TTE was 865 ± 345 s, 165 ± 98 s and 117 ± 45 s for the 80, 100 and 105% trials respectively. Average power output was higher for TTE (294 ± 44 W) compared to TT (282 ± 43 W) at 80% MAP (P < 0.01), but not at 100 and 105% MAP (P > 0.05). There was no difference in cadence, HR, or RPE for any trial (P > 0.05). Critical power (CP) was also higher when derived from TTE compared to TT (P < 0.01). It is concluded that TTE results in a higher average power output compared to TT at 80% MAP. When determining CP, TTE rather than TT protocols appear superior.
18 CFR 39.3 - Electric Reliability Organization certification.
Code of Federal Regulations, 2010 CFR
2010-04-01
... operators of the Bulk-Power System, and other interested parties for improvement of the Electric Reliability... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Electric Reliability..., Reliability Standards that provide for an adequate level of reliability of the Bulk-Power System, and (2) Has...
14 CFR 171.271 - Installation requirements.
Code of Federal Regulations, 2010 CFR
2010-01-01
... generated. Adequate power capacity must be provided for the operation of test and working equipment of the... restoration of power, the batteries must be restored to full charge within 24 hours. When primary power is... battery must permit continuation of normal operation for at least two hours under the normal operating...
Stow, Ruth; Ives, Natalie; Smith, Christina; Rick, Caroline; Rushton, Alison
2015-09-28
Protein energy malnutrition (PEM) predisposes individuals to disease, delays recovery from illness and reduces quality of life. Care home residents in the United Kingdom are especially vulnerable, with an estimated 30 to 42 % at risk. Evidence for nutritional interventions to address PEM in the care home setting is lacking. Widely used techniques include food-based intervention and/or the use of prescribed oral nutritional supplements. To define outcomes and optimise the design for an adequately powered definitive trial to compare the efficacy of established nutritional interventions in this setting, a cluster randomised feasibility trial with a 6-month intervention was undertaken. Care home residents with or at risk of malnutrition were identified across six UK care home sites from September to December 2013. Homes were cluster randomised to standard care (SC), food-based intervention (FB) or oral nutritional supplement intervention (ONS), for 6 months. Key outcomes were trial feasibility and the acceptability of design, allocated interventions and outcome assessments. Anthropometry, dietary intake, healthcare resource usage and participant-reported outcome measures were assessed at baseline and at 3 and 6 months. All six care homes approached were recruited and retained. Of the 110 residents at risk of malnutrition, 85 % entered the trial, and 68 % completed the 6-month intervention. Pre-specified success criteria for feasibility were met for recruitment and retention, intervention acceptability (resident compliance ≥60 %) and measurement of weight, body mass index (BMI), mid-upper arm circumference and dietary intake (data completeness >80 %). Measurement of handgrip strength and triceps skinfold thickness was not found to be feasible in this population. The 95 % confidence interval (CI) data suggested sensitivity to change in dietary intake for weight, BMI and energy intake between baseline and 3 months when each intervention (FB and ONS) was compared with SC. A definitive trial comparing the efficacy of nutritional support interventions in increasing weight and BMI in malnourished care home residents can be conducted. However, whilst the design was feasible, this trial has highlighted the lack of clinically and patient-relevant outcome measures that are appropriate for use in this setting for both research and clinical practice. In particular, this trial identified a need for a more simple measure of functional status, which considers the limitations of functional tests in the care home population. Current Controlled Trials ISRCTN38047922 , Date assigned: 22 April 2014.
Epidural blood patching for preventing and treating post-dural puncture headache.
Sudlow, C; Warlow, C
2002-01-01
Dural puncture is a common procedure, but leakage of CSF from the resulting dural defect may cause postural headache after the procedure, and this can be disabling. Injecting an epidural blood patch around the site of the defect may stop this leakage, and so may have a role in preventing or treating post dural puncture headache. To assess the possible benefits and harms of epidural blood patching in both the prevention and the treatment of post-dural puncture headache. We searched the Cochrane Controlled Trials Register (Cochrane Library, Issue 4, 2000), MEDLINE (January 1994 to December 1998), and EMBASE (January 1980 to December 1998). We also searched the reference lists of relevant articles identified electronically, and asked both the authors of all included trials and colleagues with an interest in this area to let us know of any other potentially relevant studies not already identified. Date of last search: December 2000. We sought all properly randomised, unconfounded trials that compared epidural blood patch versus no epidural blood patch in the prevention or treatment of post-dural puncture headache among all types of patients undergoing dural puncture for any reason. The primary outcome of effectiveness was postural headache. One reviewer extracted details of trial methodology and outcome data from the reports of all trials considered eligible for inclusion. We invited the authors of all such trials both to check the information extracted and to provide any details that were unavailable in the published reports. Intention-to-treat analyses were performed using the Peto O-E method. Information about adverse effects (post-dural puncture backache, epidural infection and lower limb paraesthesia) was also extracted. Three trials (77 patients) were eligible for inclusion. Methodological details were generally incomplete. Although the results of our analyses suggested that both prophylactic and therapeutic epidural blood patching may be of benefit, the very small numbers of patients and outcome events, as well as uncertainties about trial methodology, precluded reliable assessments of the potential benefits and harms of this intervention. Further, adequately powered, randomised trials (including at least a few hundred patients) are required before reliable conclusions can be drawn about the role of epidural blood patching in the prevention and treatment of post-dural puncture headache.
Treatment of painful diabetic peripheral neuropathy.
Rosenberg, Casandra J; Watson, James C
2015-02-01
Painful diabetic peripheral neuropathy impairs quality of life and can be difficult to treat. To discuss current treatment recommendations for painful diabetic peripheral neuropathy. Literature review. Systematic review of the literature discussing treatment of painful diabetic peripheral neuropathy. Existing treatment guidelines were studied and compared. Painful diabetic peripheral neuropathy occurs in about one in six people with diabetes. This condition impairs quality of life and increases healthcare costs. Treatment recommendations exist, but individual patient therapy can require a trial-and-error approach. Many treatment options have adjuvant benefits or side effects which should be considered prior to initiating therapy. Often, a combination of treatment modalities with various mechanisms of action is required for adequate pain control. Adequate medication titration and a reasonable trial period should be allowed. The treatment of painful diabetic peripheral neuropathy can be challenging, but effective management can improve patient's quality of life. Painful diabetic peripheral neuropathy impairs quality of life and can be difficult to treat. Many treatment options have adjuvant benefits or side effects which should be considered prior to initiating therapy. Often, a combination of treatment modalities with various mechanisms of action is required for adequate pain control. © The International Society for Prosthetics and Orthotics 2014.
Creatine for women in pregnancy for neuroprotection of the fetus.
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.
Washout policies in long-term indwelling urinary catheterisation in adults.
Shepherd, Ashley J; Mackay, William G; Hagen, Suzanne
2017-03-06
People requiring long-term bladder draining with an indwelling catheter can experience catheter blockage. Regimens involving different solutions can be used to wash out catheters with the aim of preventing blockage. This is an update of a review published in 2010. To determine if certain washout regimens are better than others in terms of effectiveness, acceptability, complications, quality of life and critically appraise and summarise economic evidence for the management of long-term indwelling urinary catheterisation in adults. We searched the Cochrane Incontinence Group Specialised Trials Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, CINAHL, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings to 23 May 2016. We also examined all reference lists of identified trials and contacted manufacturers and researchers in the field. 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 (aged 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. Two review authors independently extracted data. Disagreements were resolved by discussion. Data were assessed and analysed as described in the Cochrane Handbook. If data in trials were not fully reported, clarification was sought from the study authors. For categorical outcomes, the numbers reporting an outcome were related to the numbers at risk in each group to derive a risk ratio (RR). For continuous outcomes, means and standard deviations were used to derive mean differences (MD). We included seven trials involving a total of 349 participants, 217 of whom completed the studies. Three were cross-over and four were parallel-group randomised controlled trials (RCTs). Of these, two trials were added for this update (one parallel-group RCT with 40 participants and one cross-over RCT with 67 participants). Analyses of three cross-over trials yielded suboptimal results because they were based on between-group differences rather than individual participants' differences for sequential interventions. Two parallel-group trials had limited clinical value: one combined results for suprapubic and urethral catheters and the other provided data for only four participants. Only one trial was free of significant methodological limitations, but there were difficulties with recruitment and maintaining participants in this study.The included studies reported data on six of the nine primary and secondary outcome measures. None of the trials addressed: number of catheters used, washout acceptability measures (including patient satisfaction, patient discomfort, pain and ease of use), or health status/measures of psychological health; very limited data were collected for health economic outcomes. Trials assessed only three of the eight intervention comparisons identified. Two trials reported in more than one comparison group.Four trials compared washout (either saline or acidic solution) with no washout. We are uncertain if washout solutions (saline or acidic), compared to no washout solutions, has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because the results are imprecise.Four trials compared different types of washout solution; saline versus acidic solutions (2 trials); saline versus acidic solution versus antibiotic solution (1 trial); saline versus antimicrobial solution (1 trial). We are uncertain if type of washout solution has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because the results are imprecise.One trial compared different compositions of acidic solution (stronger versus weaker solution). We are uncertain if different compositions of acidic solutions has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because only 14 participants (of 25 who were recruited) completed this 12 week, three arm trial.Four studies reported on possible harmful effects of washout use, such as blood in the washout solution, changes in blood pressure and bladder spasms.There were very few small trials that met the review inclusion criteria. The high risk of bias of the included studies resulted in the evidence being graded as low or very low quality. Data from seven trials that compared different washout policies were limited, and generally, of poor methodological quality or were poorly reported. The evidence was not adequate to conclude if washouts were beneficial or harmful. Further rigorous, high quality trials that are adequately powered to detect benefits from washout being performed as opposed to no washout are needed. Trials comparing different washout solutions, washout volumes, and frequencies or timings are also needed.
ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review
Appleton, Katherine M; Sallis, Hannah M; Perry, Rachel; Ness, Andrew R; Churchill, Rachel
2016-01-01
Objective To assess the effects of n-3 polyunsaturated fatty acids (n-3PUFAs; also known as ω-3 fatty acids) compared with comparator for major depressive disorder (MDD) in adults. Design Systematic review and meta-analyses. Data sources The Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Registers (CCDANCTR) and International Trial Registries searched to May 2015. CINAHL searched to September 2013. Trial selection Inclusion criteria: a randomised controlled trial (RCT); that provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and was conducted in adults with MDD. Outcomes Primary outcomes were depressive symptomology and adverse events. Results 20 trials encompassing 26 relevant studies were found. For n-3PUFAs versus placebo, n-3PUFA supplementation resulted in a small-to-modest benefit for depressive symptomology: SMD=−0.32 (95% CI −0.52 to −0.12; 25 studies, 1373 participants, very low-quality evidence), but this effect is unlikely to be clinically meaningful, is very imprecise and, based on funnel plot inspection, sensitivity analyses and comparison with large well-conducted trials, is likely to be biased. Considerable evidence of heterogeneity between studies was also found, and was not explained by subgroup or sensitivity analyses. Numbers of individuals experiencing adverse events were similar in intervention and placebo groups (OR=1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence). For n-3PUFAs versus antidepressants, no differences were found between treatments in depressive symptomology (MD=−0.70 (95% CI −5.88 to 4.48); 1 study, 40 participants, very low-quality evidence). Conclusions At present, we do not have sufficient evidence to determine the effects of n-3PUFAs as a treatment for MDD. Further research in the form of adequately powered RCTs is needed. PMID:26936905
Psychological therapies for thalassaemia.
Anie, Kofi A; Massaglia, Pia
2014-03-06
Thalassaemia is a group of genetic blood disorders characterised by the absence or reduction in the production of haemoglobin. Severity is variable from less severe anaemia, through thalassaemia intermedia, to profound severe anaemia (thalassaemia major). In thalassaemia major other complications include growth retardation, bone deformation, and enlarged spleen. Blood transfusion is required to treat severe forms of thalassaemia, but this results in excessive accumulation of iron in the body (iron overload), removed mostly by a drug called desferrioxamine through 'chelation therapy'. Non-routine treatments are bone marrow transplantation (which is age restricted), and possibly hydroxyurea, designed to raise foetal haemoglobin level, thus reducing anaemia. In addition, psychological therapies seem appropriate to improving outcome and adherence to medical treatment. To examine the evidence that in people with thalassaemia, psychological treatments improve the ability to cope with the condition, and improve both medical and psychosocial outcomes. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Searches on the Internet were also performed.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 11 November 2013. All randomised or quasi-randomised controlled trials comparing the use of psychological intervention to no (psychological) intervention in people with thalassaemia. No trials of psychological therapies have been found in the literature for inclusion in this review. There are currently no results to be reported. As a chronic disease with a considerable role for self-management, psychological support seems appropriate for managing thalassaemia. However, from the information currently available, no conclusions can be made about the use of specific psychological therapies in thalassaemia. This systematic review has clearly identified the need for well-designed, adequately-powered, multicentre, randomised controlled trials assessing the effectiveness of specific psychological interventions for thalassaemia.
Catenacci, Daniel V T
2015-05-01
The promise of 'personalized cancer care' with therapies toward specific molecular aberrations has potential to improve outcomes. However, there is recognized heterogeneity within any given tumor-type from patient to patient (inter-patient heterogeneity), and within an individual (intra-patient heterogeneity) as demonstrated by molecular evolution through space (primary tumor to metastasis) and time (after therapy). These issues have become hurdles to advancing cancer treatment outcomes with novel molecularly targeted agents. Classic trial design paradigms are challenged by heterogeneity, as they are unable to test targeted therapeutics against low frequency genomic 'oncogenic driver' aberrations with adequate power. Usual accrual difficulties to clinical trials are exacerbated by low frequencies of any given molecular driver. To address these challenges, there is need for innovative clinical trial designs and strategies implementing novel diagnostic biomarker technologies to account for inter-patient molecular diversity and scarce tissue for analysis. Importantly, there is also need for pre-defined treatment priority algorithms given numerous aberrations commonly observed within any one individual sample. Access to multiple available therapeutic agents simultaneously is crucial. Finally intra-patient heterogeneity through time may be addressed by serial biomarker assessment at the time of tumor progression. This report discusses various 'next-generation' biomarker-driven trial designs and their potentials and limitations to tackle these recognized molecular heterogeneity challenges. Regulatory hurdles, with respect to drug and companion diagnostic development and approval, are considered. Focus is on the 'Expansion Platform Design Types I and II', the latter demonstrated with a first example, 'PANGEA: Personalized Anti-Neoplastics for Gastro-Esophageal Adenocarcinoma'. Applying integral medium-throughput genomic and proteomic assays along with a practical biomarker assessment and treatment algorithm, 'PANGEA' attempts to address the problem of heterogeneity towards successful implementation of molecularly targeted therapies. Copyright © 2014 The Author. Published by Elsevier B.V. All rights reserved.
2014-01-01
Background Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games –i.e. active games- may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. Methods/Design The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12 – 16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents’ measured BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents’ self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. Discussion This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents. Trial registration Dutch Trial register NTR3228. PMID:24661535
Wiangkham, Taweewat; Duda, Joan; Haque, M Sayeed; Price, Jonathan; Rushton, Alison
2016-07-13
Whiplash-associated disorder (WAD) causes substantial social and economic burden internationally. Up to 60% of patients with WAD progress to chronicity. Research therefore needs to focus on effective management in the acute stage to prevent the development of chronicity. Approximately 93% of patients are classified as WADII (neck complaint and musculoskeletal sign(s)), and in the UK, most are managed in the private sector. In our recent systematic review, a combination of active and behavioural physiotherapy was identified as potentially effective in the acute stage. An Active Behavioural Physiotherapy Intervention (ABPI) was developed through combining empirical (modified Delphi study) and theoretical (social cognitive theory focusing on self-efficacy) evidence. This pilot and feasibility trial has been designed to inform the design of an adequately powered definitive randomised controlled trial. Two parallel phases. (1) An external pilot and feasibility cluster randomised double-blind (assessor and participants), parallel two-arm (ABPI vs standard physiotherapy) clinical trial to evaluate procedures and feasibility. Six UK private physiotherapy clinics will be recruited and cluster randomised by a computer-generated randomisation sequence. Sixty participants (30 each arm) will be assessed at recruitment (baseline) and at 3 months postbaseline. The planned primary outcome measure is the neck disability index. (2) An embedded exploratory qualitative study using semistructured indepth interviews (n=3-4 physiotherapists) and a focus group (n=6-8 patients) and entailing the recruitment of purposive samples will explore perceptions of the ABPI. Quantitative data will be analysed descriptively. Qualitative data will be coded and analysed deductively (identify themes) and inductively (identify additional themes). This trial is approved by the University of Birmingham Ethics Committee (ERN_15-0542). ISRCTN84528320. 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/
Nieuwenhuis-Ruifrok, A E; Kuchenbecker, W K H; Hoek, A; Middleton, P; Norman, R J
2009-01-01
Women of reproductive age, who are overweight or obese, are prone to infertility. Weight loss in these women leads to increased fecundity, higher chances of conception after infertility treatment and improved pregnancy outcome. In spite of the advantages, most patients have difficulty in losing weight and often regain lost weight over time. This review assesses whether treatment with insulin sensitizing drugs contributes to weight loss, compared with diet or a lifestyle modification programme. After a systematic search of the literature, only randomized controlled trials (RCTs), investigating the effect of insulin sensitizing drugs on weight loss compared with placebo and diet and/or a lifestyle modification programme, were included. Subjects were restricted to women of reproductive age. The main outcome measure was change in body mass index (BMI). Only 14 trials, unintentionally all but two on women with polycystic ovary syndrome (PCOS) only, were included in the analysis. Treatment with metformin showed a statistically significant decrease in BMI compared with placebo (weighted mean difference, -0.68; 95% CI -1.13 to -0.24). There was some indication of greater effect with high-dose metformin (>1500 mg/day) and longer duration of therapy (>8 weeks). Limitations were power, low use of intention-to-treat analysis and heterogeneity of the studies. A structured lifestyle modification programme to achieve weight loss should still be the first line treatment in obese women with or without PCOS. Adequately powered RCTs are required to confirm the findings of this review and to assess whether the addition of high-dose metformin therapy to a structured lifestyle modification programme might contribute to more weight loss.
Chan, Robin F.; Shabalin, Andrey A.; Xie, Lin Y.; Adkins, Daniel E.; Zhao, Min; Turecki, Gustavo; Clark, Shaunna L.; Aberg, Karolina A.
2017-01-01
Abstract Methylome-wide association studies are typically performed using microarray technologies that only assay a very small fraction of the CG methylome and entirely miss two forms of methylation that are common in brain and likely of particular relevance for neuroscience and psychiatric disorders. The alternative is to use whole genome bisulfite (WGB) sequencing but this approach is not yet practically feasible with sample sizes required for adequate statistical power. We argue for revisiting methylation enrichment methods that, provided optimal protocols are used, enable comprehensive, adequately powered and cost-effective genome-wide investigations of the brain methylome. To support our claim we use data showing that enrichment methods approximate the sensitivity obtained with WGB methods and with slightly better specificity. However, this performance is achieved at <5% of the reagent costs. Furthermore, because many more samples can be sequenced simultaneously, projects can be completed about 15 times faster. Currently the only viable option available for comprehensive brain methylome studies, enrichment methods may be critical for moving the field forward. PMID:28334972
Recruitment of black and Latina women to a randomized controlled trial.
Martin, Anika; Negron, Rennie; Balbierz, Amy; Bickell, Nina; Howell, Elizabeth A
2013-08-01
Minority women are often not adequately represented in randomized controlled trials, limiting the generalizability of research trial results. We implemented a recruitment strategy for a postpartum depression prevention trial that utilized patient feedback to identify and understand the recruitment barriers of black and Latina postpartum women. Feedback on patients' reasons for trial refusal informed adaptations to the recruitment process. We calculated weekly recruitment rates and analyzed qualitative and quantitative data from patient refusals. Of the 668 women who were approached and completed the consent process, 540 enrolled in the trial and 128 declined participation. Over 52-weeks of recruitment, refusal rates decreased from 40% to 19%. A taxonomy of eight reasons for refusal derived from patient responses identified barriers to recruitment and generated targeted revisions to the recruitment message. A recruitment strategy designed to incorporate and respond to patient feedback improved recruitment of Black and Latina women to a clinical trial.
Carter, Rickey E; Sonne, Susan C; Brady, Kathleen T
2005-01-01
Background Adequate participant recruitment is vital to the conduct of a clinical trial. Projected recruitment rates are often over-estimated, and the time to recruit the target population (accrual period) is often under-estimated. Methods This report illustrates three approaches to estimating the accrual period and applies the methods to a multi-center, randomized, placebo controlled trial undergoing development. Results Incorporating known sources of accrual variation can yield a more justified estimate of the accrual period. Simulation studies can be incorporated into a clinical trial's planning phase to provide estimates for key accrual summaries including the mean and standard deviation of the accrual period. Conclusion The accrual period of a clinical trial should be carefully considered, and the allocation of sufficient time for participant recruitment is a fundamental aspect of planning a clinical trial. PMID:15796782
HIV vaccine trials: critical issues in informed consent.
Lindegger, G; Richter, L M
2000-06-01
Informed consent (IC), a fundamental principle of ethics in medical research, is recognized as a vital component of HIV vaccine trials. There are different notions of IC, some legally based and others based on ethics. It is argued that, though legal indemnity is necessary, vaccine trials should be founded on fully ethical considerations. Various contentious aspects of IC are examined, especially the problem of social desirability and of adequate comprehension. The need for sensitivity to cultural norms in implementing IC procedures is critically reviewed, and some of the potential conflict between ethos and ethics is considered. The transmission of information is examined as a particular aspect of IC in HIV vaccine trials.
Randomised clinical trial: rifaximin versus placebo for the treatment of functional dyspepsia.
Tan, V P Y; Liu, K S H; Lam, F Y F; Hung, I F N; Yuen, M F; Leung, W K
2017-03-01
Gut dysbiosis may contribute to pain and bloating in patients with functional gastrointestinal disease. To determine if treatment with rifaximin would improve the symptoms of functional dyspepsia in Chinese patients in a double-blinded, randomised, placebo-controlled trial. Consecutive subjects with a diagnosis of functional dyspepsia as per the Rome III criteria were randomised to receive rifaximin 400 mg or placebo, all taken three times daily for 2 weeks. The investigators and study subjects were blinded to the treatment allocation. Subjects were followed up for 8 weeks. The primary end point was adequate relief of global dyspeptic symptoms (GDS). Secondary endpoints were relief of individual dyspeptic symptoms. Eighty-six subjects were recruited. At week 8, there were significantly more subjects in the rifaximin than in the placebo group who experienced adequate relief of GDS (78% vs. 52%, P = 0.02). A trend favouring rifaximin group was also noted in the preceding 4 weeks. Rifaximin was also superior to placebo in providing adequate relief of belching and post-prandial fullness/bloating (PPF) in subjects at week 4. Subgroup analysis revealed that female subjects had more significant response to rifaximin treatment (adequate relief of GDS at week 4: 76% vs. 42%, P = 0.006; week 8: 79% vs. 47%, P = 0.008), as well as improvements in their belching and PPF at week 4. The incidences of adverse effects were similar in both groups. Treatment with 2 weeks of rifaximin led to adequate relief of global dyspeptic symptoms, belching and post-prandial fullness/bloating in subjects with functional dyspepsia. The difference was more marked in females. (clinicaltrials.org NCT01643083). © 2017 John Wiley & Sons Ltd.
Power output measurement during treadmill cycling.
Coleman, D A; Wiles, J D; Davison, R C R; Smith, M F; Swaine, I L
2007-06-01
The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The speed, gradient and loading via an external pulley system were recorded during 20-s constant speed trials and used to estimate power output with an assumption about the contribution of rolling resistance. These values were then compared with mobile ergometer measurements. To assess the reliability of measured power output values, four repeated trials were conducted on each cyclist. During level cycling, the recorded power output was 257.2 +/- 99.3 W compared to the predicted power output of 258.2 +/- 99.9 W (p > 0.05). For graded cycling, there was no significant difference between measured and predicted power output, 268.8 +/- 109.8 W vs. 270.1 +/- 111.7 W, p > 0.05, SEE 1.2 %. The coefficient of variation for mobile ergometer power output measurements during repeated trials ranged from 1.5 % (95 % CI 1.2 - 2.0 %) to 1.8 % (95 % CI 1.5 - 2.4 %). These results indicate that treadmill cycling can be used as an ergometry system to assess power output in cyclists with acceptable accuracy.
Interventions for treating osteoarthritis of the big toe joint.
Zammit, Gerard V; Menz, Hylton B; Munteanu, Shannon E; Landorf, Karl B; Gilheany, Mark F
2010-09-08
Osteoarthritis affecting of the big toe joint of the foot (hallux limitus or rigidus) is a common and painful condition. Although several treatments have been proposed, few have been adequately evaluated. To identify controlled trials evaluating interventions for osteoarthritis of the big toe joint and to determine the optimum intervention(s). Literature searches were conducted across the following electronic databases: CENTRAL; MEDLINE; EMBASE; CINAHL; and PEDro (to 14th January 2010). No language restrictions were applied. Randomised controlled trials, quasi-randomised trials, or controlled clinical trials that assessed treatment outcomes for osteoarthritis of the big toe joint. Participants of any age or gender with osteoarthritis of the big toe joint (defined either radiographically or clinically) were included. Two authors examined the list of titles and abstracts identified by the literature searches. One content area expert and one methodologist independently applied the pre-determined inclusion and exclusion criteria to the full text of identified trials. To minimise error and reduce potential bias, data were extracted independently by two content experts. Only one trial satisfactorily fulfilled the inclusion criteria and was included in this review. This trial evaluated the effectiveness of two physical therapy programs in 20 individuals with osteoarthritis of the big toe joint. Assessment outcomes included pain levels, big toe joint range of motion and plantar flexion strength of the hallux. Mean differences at four weeks follow up were 3.80 points (95% CI 2.74 to 4.86) for self reported pain, 28.30 degrees (95% CI 21.37 to 35.23) for big toe joint range of motion, and 2.80 kg (95% CI 2.13 to 3.47) for muscle strength. Although differences in outcomes between treatment and control groups were reported, the risk of bias was high. The trial failed to employ appropriate randomisation or adequate allocation concealment, used a relatively small sample and incorporated a short follow up (four weeks). No adverse reactions were reported. The reviewed trial presented a high risk of bias, which limited conclusions that could be drawn from the presented data. The inclusion of only one trial indicates the need for more robust randomised controlled trials to determine the efficacy of interventions for this condition.
Options for Affordable Fission Surface Power Systems
NASA Technical Reports Server (NTRS)
Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise
2006-01-01
Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems.
Developing a Resilient Green Cellular Network
2013-12-01
to provide BS autonomy from grid power through alternative energy, such as: fuel cells and xiii renewable photovoltaic (PV), wind energy...stations with adequate backup power or utilizing alternative/renewable energy technology such as photovoltaic or wind power to allow them to...mitigating strategies with the consensus view on BSs migrating away from grid power , to renewable energy ( photovoltaic ), and alternative fuels. 40
46 CFR 169.672 - Wiring for power and lighting circuits.
Code of Federal Regulations, 2011 CFR
2011-10-01
...) Wiring for power and lighting circuits must have copper conductors, of 14 AWG or larger, and— (1) Meet... must have stranded conductors. (c) Conductors must be sized so that— (1) They are adequate for the...
Rosenblum, Katherine L; Muzik, Maria; Morelen, Diana M; Alfafara, Emily A; Miller, Nicole M; Waddell, Rachel M; Schuster, Melisa M; Ribaudo, Julie
2017-10-01
We conducted a study to evaluate the effectiveness of Mom Power, a multifamily parenting intervention to improve mental health and parenting among high-risk mothers with young children in a community-based randomized controlled trial (CB-RCT) design. Participants (N = 122) were high-risk mothers (e.g., interpersonal trauma histories, mental health problems, poverty) and their young children (age <6 years), randomized either to Mom Power, a parenting intervention (treatment condition), or weekly mailings of parenting information (control condition). In this study, the 13-session intervention was delivered by community clinicians trained to fidelity. Pre- and post-trial assessments included mothers' mental health symptoms, parenting stress and helplessness, and connection to care. Mom Power was delivered in the community with fidelity and had good uptake (>65%) despite the risk nature of the sample. Overall, we found improvements in mental health and parenting stress for Mom Power participants but not for controls; in contrast, control mothers increased in parent-child role reversal across the trial period. The benefits of Mom Power treatment (vs. control) were accentuated for mothers with interpersonal trauma histories. Results of this CB-RCT confirm the effectiveness of Mom Power for improving mental health and parenting outcomes for high-risk, trauma-exposed women with young children. ClinicalTrials.gov Identifier: NCT01554215.
Alexander, Neal; Cundill, Bonnie; Sabatelli, Lorenzo; Bethony, Jeffrey M.; Diemert, David; Hotez, Peter; Smith, Peter G.; Rodrigues, Laura C.; Brooker, Simon
2011-01-01
Vaccines against human helminths are being developed but the choice of optimal parasitological endpoints and effect measures to assess their efficacy has received little attention. Assuming negative binomial distributions for the parasite counts, we rank the statistical power of three measures of efficacy: ratio of mean parasite intensity at the end of the trial, the odds ratio of infection at the end of the trial, and the rate ratio of incidence of infection during the trial. We also use a modelling approach to estimate the likely impact of trial interventions on the force of infection, and hence statistical power. We conclude that (1) final mean parasite intensity is a suitable endpoint for later phase vaccine trials, and (2) mass effects of trial interventions are unlikely to appreciably reduce the force of infection in the community – and hence statistical power – unless there is a combination of high vaccine efficacy and a large proportion of the population enrolled. PMID:21435404
Schmidt, Barbara; Seshia, Mary; Shankaran, Seetha; Mildenhall, Lindsay; Tyson, Jon; Lui, Kei; Fok, Tai; Roberts, Robin
2011-07-01
To examine whether treatment with antenatal corticosteroids modifies the immediate and long-term effects of prophylactic indomethacin sodium trihydrate in extremely low-birth-weight infants. Post hoc subgroup analysis of data from the Trial of Indomethacin Prophylaxis in Preterms. Thirty-two neonatal intensive care units in Canada, the United States, Australia, New Zealand, and Hong Kong. A total of 1195 infants with birth weights of 500 to 999 g and known exposure to antenatal corticosteroids. We defined as adequate any exposure to antenatal corticosteroids that occurred at least 24 hours before delivery. Indomethacin or placebo intravenously once daily for the first 3 days. Death or survival to 18 months with cerebral palsy, cognitive delay, severe hearing loss, or bilateral blindness; severe periventricular and intraventricular hemorrhage; patent ductus arteriosus; and surgical closure of a patent ductus arteriosus. Of the 1195 infants in this analysis cohort, 670 had adequate and 525 had inadequate exposure to antenatal corticosteroids. There was little statistical evidence of heterogeneity in the effects of prophylactic indomethacin between the subgroups for any of the outcomes. The adjusted P values for interaction were as low as .15 for the outcome of death or impairment at 18 months and as high as .80 for the outcome of surgical duct closure. We find little evidence that the effects of prophylactic indomethacin vary in extremely low-birth-weight infants with and without adequate exposure to antenatal corticosteroids. Trial Registration clinicaltrials.gov Identifier: NCT00009646.
Nurse-Led Programs to Facilitate Enrollment to Children's Oncology Group Cancer Control Trials.
Haugen, Maureen; Kelly, Katherine Patterson; Leonard, Marcia; Mills, Denise; Sung, Lillian; Mowbray, Catriona; Landier, Wendy
2016-09-01
The progress made over the past 50 years in disease-directed clinical trials has significantly increased cure rates for children and adolescents with cancer. The Children's Oncology Group (COG) is now conducting more studies that emphasize improving quality of life for young people with cancer. These types of clinical trials are classified as cancer control (CCL) studies by the National Cancer Institute and require different resources and approaches to facilitate adequate accrual and implementation at COG institutions. Several COG institutions that had previously experienced problems with low accruals to CCL trials have successfully implemented local nursing leadership for these types of studies. Successful models of nurses as institutional leaders and "champions" of CCL trials are described. © 2015 by Association of Pediatric Hematology/Oncology Nurses.
Implementation Considerations for Multisite Clinical Trials with Cognitive Neuroscience Tasks
Keefe, Richard S. E.; Harvey, Philip D.
2008-01-01
Multisite clinical trials aimed at cognitive enhancement across various neuropsychiatric conditions have employed standard neuropsychological tests as outcome measures. While these tests have enjoyed wide clinical use and have proven reliable and predictive of functional disability, a number of implementation challenges have arisen when these tests are used in clinical trials. These issues are likely to be magnified in future studies when cognitive neuroscience (CN) procedures are explored in these trials, because in their current forms CN procedures are less standardized and more difficult to teach and monitor. For multisite trials, we anticipate that the most challenging issues will include assuring tester competence, monitoring tester performance, specific challenges with complex assessment methods, and having resources available for adequate monitoring of data quality. Suggestions for overcoming these implementation challenges are offered. PMID:18495645
Interferon after surgery for women with advanced (Stage II-IV) epithelial ovarian cancer.
Lawal, Aramide O; Musekiwa, Alfred; Grobler, Liesl
2013-06-06
Epithelial ovarian cancer (EOC) is a life-threatening disease. Most often women become symptomatic only in the advanced stages of the disease, increasing the difficulty of treatment. Whilst the disease responds well to surgery and chemotherapy, the relapse rate is high. New treatments to prevent disease recurrence or progression, prolong survival, and increase the quality of life are needed. To assess the effectiveness and safety of interferon after surgery in the treatment of advanced (stage II-IV) EOC. The Cochrane Gynaecological Cancer Review Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL) Issue 1, 2012, MEDLINE and EMBASE were searched to January 2012. Handsearching of conference proceedings was also undertaken. Reference lists of reviews and included trials were screened and experts in the field were contacted for additional trials. Clinical trials registers were searched for ongoing trials. Randomised controlled trials (RCTs) involving participants with advanced EOC that compared post-operative chemotherapy alone with post-operative interferon therapy in combination with chemotherapy or post-operative chemotherapy followed by interferon or observation alone Two review authors (AL and AM) independently screened the search results for relevant trials and extracted pre-specified information from each included trial. Data were managed using Review Manager 5.1. Hazard ratios (HR) were calculated for time-to-event outcomes and risk ratios (RR) for dichotomous outcomes, with corresponding 95% confidence intervals (CI). Five trials, including 1476 participants, were included in the review. Two trials compared interferon with observation alone and three trials compared interferon plus chemotherapy with chemotherapy alone. A meta-analysis of two trials involving 370 participants found no significant difference in both overall survival (HR 1.14, 95% CI 0.84 to 1.55) and progression free survival (HR 0.99, 95% CI 0.79 to 1.24) between the interferon and observation alone groups in post-surgical women who had undergone first-line chemotherapy for advanced EOC. One trial with 293 participants found that while no significant difference was observed in incidence of nausea or vomiting between the two treatment groups, significantly more flu-like symptoms (RR 2.25, 95% CI 1.73 to 2.91) and fatigue (RR 1.54, 95% CI 1.27 to 1.88) were reported in the interferon group. For the second comparison, a meta-analysis of two trials comprising 244 participants found that although there was no significant difference in overall survival between the interferon plus chemotherapy and the chemotherapy alone group (HR 1.14, 95% CI 0.74 to 1.76), women in the interferon plus chemotherapy group had worse progression free survival than those in the chemotherapy alone group (HR 1.43, 95% CI 1.02 to 2.00). Compared to chemotherapy alone, adding interferon to chemotherapy did not alter the incidence of adverse events in post-surgical women with advanced EOC. Implications for practice Based on low quality evidence, the addition of interferon to first-line chemotherapy did not alter the overall survival in post-surgical women with advanced EOC compared with chemotherapy alone. There is low quality evidence to suggest that interferon in combination with chemotherapy worsened the progression free survival in post-surgical women with advanced EOC compared with chemotherapy alone. There is not enough evidence that interferon therapy alone alters overall survival or progression free survival compared to observation alone in post-surgical women who have undergone first-line chemotherapy. Three of the five trials included in this review were stopped early and were, therefore, underpowered to detect any true effect of the intervention. The trials did not report the results of important outcomes in a uniform manner, preventing statistical aggregation of the results. Trial methodology was poorly reported resulting in unclear risk of bias. For clear recommendations to be made regarding the effectiveness of interferon in the treatment of advanced EOC, long-term, well conducted and adequately powered RCTs would be needed. However, the available data do not suggest that interferon has an adequately advantageous effect to warrant further investigation.
Connor, Jason T; Elm, Jordan J; Broglio, Kristine R
2013-08-01
We present a novel Bayesian adaptive comparative effectiveness trial comparing three treatments for status epilepticus that uses adaptive randomization with potential early stopping. The trial will enroll 720 unique patients in emergency departments and uses a Bayesian adaptive design. The trial design is compared to a trial without adaptive randomization and produces an efficient trial in which a higher proportion of patients are likely to be randomized to the most effective treatment arm while generally using fewer total patients and offers higher power than an analogous trial with fixed randomization when identifying a superior treatment. When one treatment is superior to the other two, the trial design provides better patient care, higher power, and a lower expected sample size. Copyright © 2013 Elsevier Inc. All rights reserved.
Xiong, Chengjie; van Belle, Gerald; Miller, J Philip; Morris, John C
2011-02-01
Therapeutic trials of disease-modifying agents on Alzheimer's disease (AD) require novel designs and analyses involving switch of treatments for at least a portion of subjects enrolled. Randomized start and randomized withdrawal designs are two examples of such designs. Crucial design parameters such as sample size and the time of treatment switch are important to understand in designing such clinical trials. The purpose of this article is to provide methods to determine sample sizes and time of treatment switch as well as optimum statistical tests of treatment efficacy for clinical trials of disease-modifying agents on AD. A general linear mixed effects model is proposed to test the disease-modifying efficacy of novel therapeutic agents on AD. This model links the longitudinal growth from both the placebo arm and the treatment arm at the time of treatment switch for these in the delayed treatment arm or early withdrawal arm and incorporates the potential correlation on the rate of cognitive change before and after the treatment switch. Sample sizes and the optimum time for treatment switch of such trials as well as optimum test statistic for the treatment efficacy are determined according to the model. Assuming an evenly spaced longitudinal design over a fixed duration, the optimum treatment switching time in a randomized start or a randomized withdrawal trial is half way through the trial. With the optimum test statistic for the treatment efficacy and over a wide spectrum of model parameters, the optimum sample size allocations are fairly close to the simplest design with a sample size ratio of 1:1:1 among the treatment arm, the delayed treatment or early withdrawal arm, and the placebo arm. The application of the proposed methodology to AD provides evidence that much larger sample sizes are required to adequately power disease-modifying trials when compared with those for symptomatic agents, even when the treatment switch time and efficacy test are optimally chosen. The proposed method assumes that the only and immediate effect of treatment switch is on the rate of cognitive change. Crucial design parameters for the clinical trials of disease-modifying agents on AD can be optimally chosen. Government and industry officials as well as academia researchers should consider the optimum use of the clinical trials design for disease-modifying agents on AD in their effort to search for the treatments with the potential to modify the underlying pathophysiology of AD.
Nateghi, Roshanak; Guikema, Seth D; Wu, Yue Grace; Bruss, C Bayan
2016-01-01
The U.S. federal government regulates the reliability of bulk power systems, while the reliability of power distribution systems is regulated at a state level. In this article, we review the history of regulating electric service reliability and study the existing reliability metrics, indices, and standards for power transmission and distribution networks. We assess the foundations of the reliability standards and metrics, discuss how they are applied to outages caused by large exogenous disturbances such as natural disasters, and investigate whether the standards adequately internalize the impacts of these events. Our reflections shed light on how existing standards conceptualize reliability, question the basis for treating large-scale hazard-induced outages differently from normal daily outages, and discuss whether this conceptualization maps well onto customer expectations. We show that the risk indices for transmission systems used in regulating power system reliability do not adequately capture the risks that transmission systems are prone to, particularly when it comes to low-probability high-impact events. We also point out several shortcomings associated with the way in which regulators require utilities to calculate and report distribution system reliability indices. We offer several recommendations for improving the conceptualization of reliability metrics and standards. We conclude that while the approaches taken in reliability standards have made considerable advances in enhancing the reliability of power systems and may be logical from a utility perspective during normal operation, existing standards do not provide a sufficient incentive structure for the utilities to adequately ensure high levels of reliability for end-users, particularly during large-scale events. © 2015 Society for Risk Analysis.
75 FR 13142 - Florida Power and Light Company; Turkey Point, Units 3 and 4; Exemption
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-18
... Light Company; Turkey Point, Units 3 and 4; Exemption 1.0 Background Florida Power and Light Company... ferritic materials of pressure-retaining components of the reactor coolant pressure boundary of light water... reactor coolant pressure boundary of light water nuclear power reactors to provide adequate margins of...
30 CFR 57.12008 - Insulation and fittings for power wires and cables.
Code of Federal Regulations, 2014 CFR
2014-07-01
... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...
30 CFR 57.12008 - Insulation and fittings for power wires and cables.
Code of Federal Regulations, 2013 CFR
2013-07-01
... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...
30 CFR 57.12008 - Insulation and fittings for power wires and cables.
Code of Federal Regulations, 2012 CFR
2012-07-01
... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...
26 CFR 20.2038-1 - Revocable transfers.
Code of Federal Regulations, 2011 CFR
2011-04-01
... subject at the date of the decedent's death to any change through the exercise of a power by the decedent to alter, amend, revoke, or terminate, or if the decedent relinquished such a power in contemplation... adequate and full consideration in money or money's worth (see § 20.2043-1); (2) If the decedent's power...
46 CFR 56.50-55 - Bilge pumps.
Code of Federal Regulations, 2010 CFR
2010-10-01
...) Each self-propelled vessel must be provided with a power-driven pump or pumps connected to the bilge... power-driven pump is required. (See Part 171 of this chapter for determination of criterion numeral.) 5... available, or where a suitable water supply is available from a power-driven pump of adequate pressure and...
Pharmacotherapy of Hypertension in Chronic Dialysis Patients
Georgianos, Panagiotis I.
2016-01-01
Among patients on dialysis, hypertension is highly prevalent and contributes to the high burden of cardiovascular morbidity and mortality. Strict volume control via sodium restriction and probing of dry weight are first-line approaches for the treatment of hypertension in this population; however, antihypertensive drug therapy is often needed to control BP. Few trials compare head-to-head the superiority of one antihypertensive drug class over another with respect to improving BP control or altering cardiovascular outcomes; accordingly, selection of the appropriate antihypertensive regimen should be individualized. To individualize therapy, consideration should be given to intra- and interdialytic pharmacokinetics, effect on cardiovascular reflexes, ability to treat comorbid illnesses, and adverse effect profile. β-Blockers followed by dihydropyridine calcium-channel blockers are our first- and second-line choices for antihypertensive drug use. Angiotensin–converting enzyme inhibitors and angiotensin receptor blockers seem to be reasonable third–line choices, because the evidence base to support their use in patients on dialysis is sparse. Add-on therapy with mineralocorticoid receptor antagonists in specific subgroups of patients on dialysis (i.e., those with severe congestive heart failure) seems to be another promising option in anticipation of the ongoing trials evaluating their efficacy and safety. Adequately powered, multicenter, randomized trials evaluating hard cardiovascular end points are urgently warranted to elucidate the comparative effectiveness of antihypertensive drug classes in patients on dialysis. In this review, we provide an overview of the randomized evidence on pharmacotherapy of hypertension in patients on dialysis, and we conclude with suggestions for future research to address critical gaps in this important area. PMID:27797886
Hogan, Shea E; L'Allier, Phillipe; Chetcuti, Stanley; Grossman, P Michael; Nallamothu, Brahmajee K; Duvernoy, Claire; Bates, Eric; Moscucci, Mauro; Gurm, Hitinder S
2008-09-01
The optimal hydration strategy for prevention of contrast-induced acute kidney injury (AKI) remains unknown. The purpose of this meta-analysis is to compare the effectiveness of normal saline (NS) versus sodium bicarbonate hydration (NaHCO(3)) for prevention of contrast-induced AKI. We performed a meta-analysis of randomized controlled trials that compared saline-based hydration with sodium bicarbonate-based hydration regimen for prophylaxis of contrast-induced AKI. The literature search included MEDLINE, EMBASE, and Cochrane databases (2000 to October 2007); conference proceedings; and bibliographies of retrieved articles. Information was extracted on study design, sample characteristics, and interventions. Random-effects models were used to calculate summary risk ratios for contrast-induced AKI, need for hemodialysis, and death. Seven trials with 1,307 subjects were included. Preprocedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of contrast-induced AKI (5.96% in the NaHCO(3) arm versus 17.23% in the NS arm, summary risk ratio 0.37, 95% CI 0.18-0.714, P = .005). There was no difference in the rates of postprocedure hemodialysis or death. Formal testing revealed moderate heterogeneity and a strong likelihood of publication bias. Although sodium bicarbonate hydration was found to be superior to NS in prevention of contrast-induced AKI, these results are in the context of study heterogeneity and, likely, publication bias. An adequately powered randomized controlled trial is warranted to define the optimal hydration strategy in patients at high risk of contrast-induced AKI who are scheduled to undergo contrast administration.
Cheville, Andrea L; Kollasch, Jenny; Vandenberg, Justin; Shen, Tiffany; Grothey, Axel; Gamble, Gail; Basford, Jeffrey R
2013-05-01
Exercise benefits patients with cancer, but studies of home-based approaches, particularly among those with Stage IV disease, remain small and exploratory. To conduct an adequately powered trial of a home-based exercise intervention that can be facilely integrated into established delivery and reimbursement structures. Sixty-six adults with Stage IV lung or colorectal cancer were randomized, in an eight-week trial, to usual care or incremental walking and home-based strength training. The exercising participants were instructed during a single physiotherapy visit and subsequently exercised four days or more per week; training and step-count goals were advanced during bimonthly telephone calls. The primary outcome measure was mobility assessed with the Ambulatory Post Acute Care Basic Mobility Short Form. Secondary outcomes included ratings of pain and sleep quality as well as the ability to perform daily activities (Ambulatory Post Acute Care Daily Activities Short Form), quality of life (Functional Assessment of Cancer Therapy-General), and fatigue (Functional Assessment of Cancer Therapy-Fatigue). Three participants dropped out and seven died (five in the intervention and two in the control group, P=0.28). At Week 8, the intervention group reported improved mobility (P=0.01), fatigue (P=0.02), and sleep quality (P=0.05) compared with the usual care group, but did not differ on the other measures. A home-based exercise program seems capable of improving the mobility, fatigue, and sleep quality of patients with Stage IV lung and colorectal cancer. Copyright © 2013. Published by Elsevier Inc.
Huckans, Marilyn; Hutson, Lee; Twamley, Elizabeth; Jak, Amy; Kaye, Jeffrey; Storzbach, Daniel
2013-01-01
Objective To evaluate the efficacy of cognitive rehabilitation therapies (CRTs) for mild cognitive impairment (MCI). Our review revealed a need for evidence-based treatments for MCI and a lack of a theoretical rehabilitation model to guide the development and evaluation of these interventions. We have thus proposed a theoretical rehabilitation model of MCI that yields key intervention targets - cognitive compromise, functional compromise, neuropsychiatric symptoms, and modifiable risk and protective factors known to be associated with MCI and dementia. Our model additionally defines specific cognitive rehabilitation approaches that may directly or indirectly target key outcomes - restorative cognitive training, compensatory cognitive training, lifestyle interventions, and psychotherapeutic techniques. Methods Fourteen randomized controlled trials met inclusion criteria and were reviewed. Results Studies markedly varied in terms of intervention approaches and selected outcome measures and were frequently hampered by design limitations. The bulk of the evidence suggested that CRTs can change targeted behaviors in individuals with MCI and that CRTs are associated with improvements in objective cognitive performance, but the pattern of effects on specific cognitive domains was inconsistent across studies. Other important outcomes (i.e., daily functioning, quality of life, neuropsychiatric symptom severity) were infrequently assessed across studies. Few studies evaluated long-term outcomes or the impact of CRTs on conversion rates from MCI to dementia or normal cognition. Conclusions Overall, results from trials are promising but inconclusive. Additional well-designed and adequately powered trials are warranted and required before CRTs for MCI can be considered evidence based. PMID:23471631
Yang, Lei; Chen, Shouming; Yang, Di; Li, Jiajin; Wu, Taixiang; Zuo, Yunxia
2018-01-01
Objective To learn about the overall quality of clinical anaesthesia study protocols from the Chinese Clinical Trials Registry and to discuss the way to improve study protocol quality. Methods We defined completeness of each sub-item in SPIRIT as N/A (not applicable) or with a score of 0, 1, or 2. For each protocol, we calculated the proportion of adequately reported items (score = 2 and N/A) and unreported items (score = 0). Protocol quality was determined according to the proportion of reported items, with values >50% indicating high quality. Protocol quality was determined according to the proportion of reported items. For each sub-item in SPIRIT, we calculated the adequately reported rate (percentage of all protocols with score 2 and NA on one sub-item) as well as the unreported rate (percentage of all protocols with score 0 on one sub-item). Results Total 126 study protocols were available for assessment. Among these, 88.1% were assessed as being of low quality. By comparison, the percentage of low-quality protocols was 88.9% after the publication of the SPIRIT statement. Among the 51 SPIRIT sub-items, 18 sub-items had an unreported rate above 90% while 16 had a higher adequately reported rate than an unreported rate. Conclusions The overall quality of clinical anaesthesia study protocols registered in the ChiCTR was poor. A mandatory protocol upload and self-check based on the SPIRIT statement during the trial registration process may improve protocol quality in the future. PMID:29872509
Barber, Julie A; Thompson, Simon G
1998-01-01
Objective To review critically the statistical methods used for health economic evaluations in randomised controlled trials where an estimate of cost is available for each patient in the study. Design Survey of published randomised trials including an economic evaluation with cost values suitable for statistical analysis; 45 such trials published in 1995 were identified from Medline. Main outcome measures The use of statistical methods for cost data was assessed in terms of the descriptive statistics reported, use of statistical inference, and whether the reported conclusions were justified. Results Although all 45 trials reviewed apparently had cost data for each patient, only 9 (20%) reported adequate measures of variability for these data and only 25 (56%) gave results of statistical tests or a measure of precision for the comparison of costs between the randomised groups. Only 16 (36%) of the articles gave conclusions which were justified on the basis of results presented in the paper. No paper reported sample size calculations for costs. Conclusions The analysis and interpretation of cost data from published trials reveal a lack of statistical awareness. Strong and potentially misleading conclusions about the relative costs of alternative therapies have often been reported in the absence of supporting statistical evidence. Improvements in the analysis and reporting of health economic assessments are urgently required. Health economic guidelines need to be revised to incorporate more detailed statistical advice. Key messagesHealth economic evaluations required for important healthcare policy decisions are often carried out in randomised controlled trialsA review of such published economic evaluations assessed whether statistical methods for cost outcomes have been appropriately used and interpretedFew publications presented adequate descriptive information for costs or performed appropriate statistical analysesIn at least two thirds of the papers, the main conclusions regarding costs were not justifiedThe analysis and reporting of health economic assessments within randomised controlled trials urgently need improving PMID:9794854
Stem Cell Trials for Cardiovascular Medicine: Ethical Rationale
Teraa, Martin; Hesam, Husna; van Delden, Johannes J.M.; Verhaar, Marianne C.; Bredenoord, Annelien L.
2014-01-01
Stem cell-based interventions provide new treatment prospects for many disease conditions, including cardiovascular disorders. Clinical trials are necessary to collect adequate evidence on (long-term) safety and efficacy of novel interventions such as stem cells, but the design and launch of clinical trials, from first-in-human studies to larger randomized controlled trials (RCTs), is scientifically and ethically challenging. Stem cells are different from traditional pharmaceuticals, surgical procedures, and medical devices in the following ways: the novelty and complexity of stem cells, the invasiveness of the procedures, and the novel aim of regeneration. These specifics, combined with the characteristics of the study population, will have an impact on the design and ethics of RCTs. The recently closed JUVENTAS trial will serve as an example to identify the (interwoven) scientific and ethical challenges in the design and launch of stem cell RCTs. The JUVENTAS trial has investigated the efficacy of autologous bone marrow cells in end-stage vascular patients, in a double-blind sham-controlled design. We first describe the choices, considerations, and experiences of the JUVENTAS team. Subsequently, we identify the main ethical and scientific challenges and discuss what is important to consider in the design of future stem cell RCTs: assessment of risks and benefits, the choice for outcome measures, the choice for the comparator, the appropriate selection of participants, and adequate informed consent. Additionally, the stem cell field is highly in the spotlight due to the (commercial) interests and expectations. This warrants a cautious pace of translation and scrupulous set up of clinical trials, as failures could put the field in a negative light. At the same time, knowledge from clinical trials is necessary for the field to progress. We conclude that in the scientifically and ethically challenging field of stem cell RCTs, researchers and clinicians have to maneuver between the Skylla of hyper accelerated translation without rigorously conducted RCTs and the Charybdis of the missed opportunity of valuable knowledge. PMID:24164351
Model-Based Diagnosis in a Power Distribution Test-Bed
NASA Technical Reports Server (NTRS)
Scarl, E.; McCall, K.
1998-01-01
The Rodon model-based diagnosis shell was applied to a breadboard test-bed, modeling an automated power distribution system. The constraint-based modeling paradigm and diagnostic algorithm were found to adequately represent the selected set of test scenarios.
Treatment for avascular necrosis of bone in people with sickle cell disease.
Martí-Carvajal, Arturo J; Solà, Ivan; Agreda-Pérez, Luis H
2014-07-10
Avascular necrosis of bone is a frequent and severe complication of sickle cell disease and its treatment is not standardised. To determine the impact of any surgical procedure compared with other surgical interventions or non-surgical procedures, on avascular necrosis of bone in people with sickle cell disease in terms of efficacy and safety. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Additional trials were sought from the reference lists of papers identified by the search strategy.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 17 March 2014. Randomised clinical trials comparing specific therapies for avascular necrosis of bone in people with sickle cell disease. Each author independently extracted data and assessed trial quality. Since only one trial was identified, meta-analysis was not possible. One trial (46 participants) was eligible for inclusion. After randomisation eight participants were withdrawn, mainly because they declined to participate in the trial. Data were analysed for 38 participants at the end of the trial. After a mean follow up of three years, hip core decompression and physical therapy did not show clinical improvement when compared with physical therapy alone using the score from the original trial (an improvement of 18.1 points for those treated with intervention therapy versus an improvement of 15.7 points with control therapy). There was no significant statistical difference between groups regarding major complications (hip pain, relative risk (RR) 0.95 (95% confidence interval (CI) 0.56 to 1.60; vaso-occlusive crises, RR 1.14 (95% CI 0.72 to 1.80; very low quality of evidence); and acute chest syndrome, RR 1.06 (95% CI 0.44 to 2.56; very low quality of evidence)). This trial did not report results on mortality or quality of life. We found no evidence that adding hip core decompression to physical therapy achieves clinical improvement in people with sickle cell disease with avascular necrosis of bone compared to physical therapy alone. However, we highlight that our conclusion is based on one trial with high attrition rates. Further randomised controlled trials are necessary to evaluate the role of hip-core depression for this clinical condition. Endpoints should focus on participants' subjective experience (e.g. quality of life and pain) as well as more objective 'time-to-event' measures (e.g. mortality, survival, hip longevity). The availability of participants to allow adequate trial power will be a key consideration for endpoint choice.
Treatment for avascular necrosis of bone in people with sickle cell disease.
Martí-Carvajal, Arturo J; Solà, Ivan; Agreda-Pérez, Luis H
2016-08-09
Avascular necrosis of bone is a frequent and severe complication of sickle cell disease and its treatment is not standardised. This is an update of a previously published Cochrane Review. To determine the impact of any surgical procedure compared with other surgical interventions or non-surgical procedures, on avascular necrosis of bone in people with sickle cell disease in terms of efficacy and safety. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Additional trials were sought from the reference lists of papers identified by the search strategy.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 27 May 2016. Randomized clinical trials comparing specific therapies for avascular necrosis of bone in people with sickle cell disease. Each author independently extracted data and assessed trial quality. Since only one trial was identified, meta-analysis was not possible. One trial (46 participants) was eligible for inclusion. After randomization eight participants were withdrawn, mainly because they declined to participate in the trial. Data were analysed for 38 participants at the end of the trial. After a mean follow up of three years, hip core decompression and physical therapy did not show clinical improvement when compared with physical therapy alone using the score from the original trial (an improvement of 18.1 points for those treated with intervention therapy versus an improvement of 15.7 points with control therapy). There was no significant statistical difference between groups regarding major complications (hip pain, risk ratio 0.95 (95% confidence interval 0.56 to 1.60; vaso-occlusive crises, risk ratio 1.14 (95% confidence interval 0.72 to 1.80; very low quality of evidence); and acute chest syndrome, risk ratio 1.06 (95% confidence interval 0.44 to 2.56; very low quality of evidence)). This trial did not report results on mortality or quality of life. We found no evidence that adding hip core decompression to physical therapy achieves clinical improvement in people with sickle cell disease with avascular necrosis of bone compared to physical therapy alone. However, we highlight that our conclusion is based on one trial with high attrition rates. Further randomized controlled trials are necessary to evaluate the role of hip-core depression for this clinical condition. Endpoints should focus on participants' subjective experience (e.g. quality of life and pain) as well as more objective 'time-to-event' measures (e.g. mortality, survival, hip longevity). The availability of participants to allow adequate trial power will be a key consideration for endpoint choice.
Physiotherapy Post Lumbar Discectomy: Prospective Feasibility and Pilot Randomised Controlled Trial
Rushton, Alison; Goodwin, Peter C.
2015-01-01
Objectives To evaluate: acceptability and feasibility of trial procedures; distribution of scores on the Roland Morris Disability Questionnaire (RMDQ, planned primary outcome); and efficient working of trial components. Design and Setting A feasibility and external pilot randomised controlled trial (ISRCTN33808269, assigned 10/12/2012) was conducted across 2 UK secondary care outpatient physiotherapy departments associated with regional spinal surgery centres. Participants Consecutive consenting patients aged >18 years; post primary, single level, lumbar discectomy. Interventions Participants were randomised to either 1:1 physiotherapy outpatient management including patient leaflet, or patient leaflet alone. Main Outcome Measures Blinded assessments were made at 4 weeks post surgery (baseline) and 12 weeks post baseline (proposed primary end point). Secondary outcomes included: Global Perceived Effect, back/leg pain, straight leg raise, return to work/function, quality of life, fear avoidance, range of movement, medication, re-operation. Results At discharge, 110 (44%) eligible patients gave consent to be contacted. 59 (54%) patients were recruited. Loss to follow up was 39% at 12 weeks, with one site contributing 83% losses. Mean (SD) RMDQ was 10.07 (5.58) leaflet and 10.52 (5.94) physiotherapy/leaflet at baseline; and 5.37 (4.91) leaflet and 5.53 (4.49) physiotherapy/leaflet at 12 weeks. 5.1% zero scores at 12 weeks illustrated no floor effect. Sensitivity to change was assessed at 12 weeks with mean (SD) change -4.53 (6.41), 95%CI -7.61 to -1.44 for leaflet; and -6.18 (5.59), 95%CI -9.01 to -3.30 for physiotherapy/leaflet. RMDQ mean difference (95%CI) between change from baseline to twelve weeks was 1.65(-2.46 to 5.75). Mean difference (95%CI) between groups at 12 weeks was -0.16 (-3.36 to 3.04). Participant adherence with treatment was good. No adverse events were reported. Conclusions Both interventions were acceptable, and it is promising that they both demonstrated a trend in reducing disability in this population. A randomised controlled trial, using a different trial design, is needed to ascertain the effectiveness of combining the interventions into a stepped care intervention and comparing to a no intervention arm. Findings will guide design changes for an adequately powered randomised controlled trial, using RMDQ as the primary outcome. Trial Registration ISRCTN registry 33808269 PMID:26562660
2013-01-01
Background Quality assessment of pediatric randomized controlled trials (RCTs) in China is limited. The aim of this study was to evaluate the quantitative trends and quality indicators of RCTs published in mainland China over a recent 10-year period. Methods We individually searched all 17 available pediatric journals published in China from January 1, 2002 to December 30, 2011 to identify RCTs of drug treatment in participants under the age of 18 years. The quality was evaluated according to the Cochrane quality assessment protocol. Results Of 1287 journal issues containing 44398 articles, a total of 2.4% (1077/44398) articles were included in the analysis. The proportion of RCTs increased from 0.28% in 2002 to 0.32% in 2011. Individual sample sizes ranged from 10 to 905 participants (median 81 participants); 2.3% of the RCTs were multiple center trials; 63.9% evaluated Western medicine, 32.5% evaluated traditional Chinese medicine; 15% used an adequate method of random sequence generation; and 10.4% used a quasi-random method for randomization. Only 1% of the RCTs reported adequate allocation concealment and 0.6% reported the method of blinding. The follow-up period was from 7 days to 96 months, with a median of 7.5 months. There was incomplete outcome data reported in 8.3%, of which 4.5% (4/89) used intention-to-treat analysis. Only 0.4% of the included trials used adequate random sequence allocation, concealment and blinding. The articles published from 2007 to 2011 revealed an improvement in the randomization method compared with articles published from 2002 to 2006 (from 2.7% to 23.6%, p = 0.000). Conclusions In mainland China, the quantity of RCTs did not increase in the pediatric population, and the general quality was relatively poor. Quality improvements were suboptimal in the later 5 years. PMID:23914882
van Tilburg, Miranda A L; Palsson, Olafur S; Ringel, Yehuda; Whitehead, William E
2014-02-01
Ginger is one of the most commonly used herbal medicines for irritable bowel syndrome (IBS) but no data exists about its effectiveness. Double blind randomized controlled trial. University of North Carolina, Chapel Hill, North Carolina, USA. Forty-five IBS patients were randomly assigned to three groups: placebo, 1g of ginger, and 2g of ginger daily for 28 days. The IBS severity scale (IBS-SS) was administered, as well as adequate relief of symptoms scale. A responder was defined as having at least 25% reduction in IBS-SS post-treatment. There were 57.1% responders to placebo, 46.7% to 1g and 33.3% to 2g of ginger. Adequate relief was reported by 53.3% on placebo and 53.3% in both ginger groups combined. Side effects were mild and reported by 35.7% in the placebo and 16.7% in the ginger groups. This double blind randomized controlled pilot study suggests ginger is well tolerated but did not perform better than placebo. Larger trials are needed before any definitive conclusions can be drawn. Copyright © 2014 Elsevier Ltd. All rights reserved.
Money and morals: ending clinical trials for financial reasons.
Eaton, Margaret L; Kwon, Brian K; Scott, Christopher Thomas
2015-01-01
Too often, biopharmaceutical companies stop their clinical trials solely for financial reasons. In this chapter, we discuss this phenomenon against the backdrop of a 2011 decision by Geron Corporation to abandon its stem cell clinical trial for spinal cord injury (SCI), the preliminary results of which were released in May 2014. We argue that the resultant harms are widespread and are different in nature from the consequences of stopping trials for scientific or medical reasons. We examine the ethical and social effects that arise from such decisions and discuss them in light of ethical frameworks, including duties of individual stakeholders and corporate sponsors. We offer ways that sponsors and clinical sites can ensure that trials are responsibly started, and once started adequately protect the interests of participants. We conclude with recommendations that industry sponsors of clinical trials should adopt in order to advance a collective and patient-centered research ethic.
Knaapen, Max; van der Lee, Johanna H; Bakx, Roel; The, Sarah-May L; van Heurn, Ernst W E; Heij, Hugo A; Gorter, Ramon R
2017-01-01
Introduction Based on epidemiological, immunological and pathology data, the idea that appendicitis is not necessarily a progressive disease is gaining ground. Two types are distinguished: simple and complicated appendicitis. Non-operative treatment (NOT) of children with simple appendicitis has been investigated in several small studies. So far, it is deemed safe. However, its effectiveness and effect on quality of life (QoL) have yet to be established in an adequately powered randomised trial. In this article, we provide the study protocol for the APAC (Antibiotics versus Primary Appendectomy in Children) trial. Methods and analysis This multicentre, non-inferiority, randomised controlled trial randomises children aged 7–17 years with imaging-confirmed simple appendicitis between appendectomy and NOT. Patients are recruited in 15 hospitals. The intended sample size, based on the primary outcome, rate of complications and a non-inferiority margin of 5%, is 334 patients. NOT consists of intravenous antibiotics for 48–72 hours, daily blood tests and ultrasound follow-up. If the patient meets the predefined discharge criteria, antibiotic treatment is continued orally at home. Primary outcome is the rate of complications at 1-year follow-up. An independent adjudication committee will assess all complications and their relation to the allocated treatment. Secondary outcomes include, but are not limited to, delayed appendectomies, QoL, pain and (in)direct costs. The primary outcome will be analysed both according to the intention-to-treat principle and the per-protocol principle, and is presented with a one-sided 97.5% CI. We will use multiple logistic and linear regression for binary and continuous outcomes, respectively, to adjust for stratification factors. Ethics and dissemination The protocol has been approved by the Medical Ethics Review Committee of the Academic Medical Center, Amsterdam. Data monitoring is performed by an independent institute and a Data Safety Monitoring Board has been assigned. Results will be presented in peer-reviewed academic journals and at (international) conferences. Trial registration number NCT02848820; NTR5977; Pre-results. PMID:29146647
2011-01-01
Introduction Mechanically ventilated critically ill patients frequently develop ventilator-associated pneumonia (VAP), a life-threatening complication. Proposed preventive measures against VAP include, but are not restricted to, selective decontamination of the digestive tract (SDD), selective oropharyngeal decontamination (SOD) and the use of probiotics. Probiotics are live bacteria that could have beneficial effects on the host by altering gastrointestinal flora. Similar to SDD and SOD, a prescription of probiotics aims at the prevention of secondary colonization of the upper and/or lower digestive tract. Methods We performed a literature review to describe the differences and similarities between SDD/SOD and probiotic preventive strategies, focusing on (a) efficacy, (b) risks, and (c) the routing of these strategies. Results Reductions in the incidence of VAP have been achieved with SDD and SOD. Two large randomized controlled trials even showed reduced mortality with these preventive strategies. Randomized controlled trials of probiotic strategies also showed a reduction of the incidence of VAP, but trials were too small to draw firm conclusions. Preventive strategies with antibiotics and probiotics may be limited due to the risk of emerging resistance to the locally applied antibiotics and the risk of probiotic-related infections, respectively. The majority of trials of SDD and SOD did not exhaustively address the issue of emerging resistance. Likewise, trials of probiotic strategies did not adequately address the risk of colonization with probiotics and probiotic-related infection. In studies of SDD and SOD the preventive strategy aimed at decontamination of the oral cavity, throat, stomach and intestines, and the oral cavity and throat, respectively. In the vast majority of studies of probiotic therapy the preventive strategy aimed at decontamination of the stomach and intestines. Conclusions Prophylactic use of antibiotics in critically ill patients is effective in reducing the incidence of VAP. Probiotic strategies deserve consideration in future well-powered trials. Future studies are needed to determine if preventive antibiotic and probiotic strategies are safe with regard to development of antibiotic resistance and probiotic infections. It should be determined whether the efficacy of probiotics improves when these agents are provided to the mouth and the intestines simultaneously. PMID:21232110
Hematopoietic stem cell transplantation for people with ß-thalassaemia major.
Jagannath, Vanitha A; Fedorowicz, Zbys; Al Hajeri, Amani; Sharma, Akshay
2016-11-30
Thalassemia is an inherited autosomal recessive blood disorder, caused by mutations in globin genes or their regulatory regions. This results in a reduced rate of synthesis of one of the globin chains that make up haemoglobin. In ß-thalassaemia major there is an underproduction of ß-globin chains combined with excess of free α-globin chains. The excess free α-globin chains precipitate in red blood cells, leading to their destruction (haemolysis) and ineffective erythropoiesis. The conventional approach to treatment is based on the correction of haemoglobin status through regular blood transfusions and iron chelation therapy for iron overload. Although conventional treatment has the capacity to improve the quality of life of people with ß-thalassaemia major, allogeneic hematopoietic stem cell transplantation is the only currently available procedure which has the curative potential. This is an update of a previously published Cochrane Review. To evaluate the effectiveness and safety of different types of allogeneic hematopoietic stem cell transplantation, in people with severe transfusion-dependant ß-thalassaemia major, ß-thalassaemia intermedia or ß0/+- thalassaemia variants requiring chronic blood transfusion. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 18 August 2016. Randomised controlled trials and quasi-randomised controlled trials comparing allogeneic hematopoietic stem cell transplantation with each other or with standard therapy (regular transfusion and chelation regimen). Two review authors independently screened studies and had planned to extract data and assess risk of bias using standard Cochrane methodologies but no studies were identified for inclusion. No relevant studies were retrieved after a comprehensive search of the literature. We were unable to identify any randomised controlled trials or quasi-randomised controlled trials on the effectiveness and safety of different types of allogeneic stem cell transplantation in people with severe transfusion-dependant ß-thalassaemia major or ß0/+- thalassaemia variants requiring chronic blood transfusion. The absence of high-level evidence for the effectiveness of these interventions emphasises the need for well-designed, adequately-powered, randomised controlled clinical trials.
Hematopoietic stem cell transplantation for people with ß-thalassaemia major.
Jagannath, Vanitha A; Fedorowicz, Zbys; Al Hajeri, Amani; Sharma, Akshay
2014-10-15
Thalassemia is an inherited blood disorder, caused by mutations in regulatory genes and transmitted as an autosomal recessive disorder, which results in a reduced rate of synthesis of one of the globin chains that make up haemoglobin. In ß-thalassaemia major there is an underproduction of ß-globin chains combined with excess of free α-globin chains. The excess free α-globin chains damage the red blood cell membranes, leading to their destruction and a phenomenon termed ineffective erythropoiesis. The conventional approach to treatment is based on the correction of haemoglobin status through regular blood transfusions and iron chelation therapy for iron overload. Although conventional treatment has the capacity to improve the quality of life of people with ß-thalassaemia major, allogeneic hematopoietic stem cell transplantation is the only currently available procedure which has the potential to definitively cure the disease. To evaluate the effectiveness and safety of different types of allogeneic hematopoietic stem cell transplantation, in people with severe transfusion-dependant ß-thalassaemia major, ß-thalassaemia intermedia or ß0/+- thalassaemia variants requiring chronic blood transfusion. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 11 November 2013. Randomised controlled trials and quasi-randomised controlled trials comparing allogeneic hematopoietic stem cell transplantation with each other or with standard therapy (regular transfusion and chelation regimen). Two review authors independently screened studies and had planned to extract data and assess risk of bias using standard Cochrane Collaboration methodologies but no studies were identified for inclusion. No relevant studies were retrieved after a comprehensive search of the literature. We were unable to identify any randomised controlled trials or quasi-randomised controlled trials on the effectiveness and safety of different types of allogeneic stem cell transplantation in people with severe transfusion-dependant ß-thalassaemia major or ß0/+- thalassaemia variants requiring chronic blood transfusion. The absence of high-level evidence for the effectiveness of these interventions emphasises the need for well-designed, adequately-powered, randomised controlled clinical trials.
2012-01-01
Background Women with cancer are significantly more likely to fall than women without cancer placing them at higher risk of fall-related fractures, other injuries and disability. Currently, no evidence-based fall prevention strategies exist that specifically target female cancer survivors. The purpose of the GET FIT (Group Exercise Training for Functional Improvement after Treatment) trial is to compare the efficacy of two distinct types of exercise, tai chi versus strength training, to prevent falls in women who have completed treatment for cancer. The specific aims of this study are to: 1) Determine and compare the efficacy of both tai chi training and strength training to reduce falls in older female cancer survivors, 2) Determine the mechanism(s) by which tai chi and strength training each reduces falls and, 3) Determine whether or not the benefits of each intervention last after structured training stops. Methods/Design We will conduct a three-group, single-blind, parallel design, randomized controlled trial in women, aged 50–75 years old, who have completed chemotherapy for cancer comparing 1) tai chi 2) strength training and 3) a placebo control group of seated stretching exercise. Women will participate in supervised study programs twice per week for six months and will be followed for an additional six months after formal training stops. The primary outcome in this study is falls, which will be prospectively tracked by monthly self-report. Secondary outcomes are maximal leg strength measured by isokinetic dynamometry, postural stability measured by computerized dynamic posturography and physical function measured by the Physical Performance Battery, all measured at baseline, 3, 6 and 12 months. The sample for this trial (N=429, assuming 25% attrition) will provide adequate statistical power to detect at least a 47% reduction in the fall rate over 1 year by being in either of the 2 exercise groups versus the control group. Discussion The GET FIT trial will provide important new knowledge about preventing falls using accessible and implementable exercise interventions for women following chemotherapy for cancer. ClinicalTrials.gov NCT01635413 PMID:23217054
Herbert, Vanessa; Kyle, Simon D; Pratt, Daniel
2018-06-01
Individuals with insomnia report difficulties pertaining to their cognitive functioning. Cognitive behavioural therapy for insomnia (CBT-I) is associated with robust, long-term improvements in sleep parameters, however less is known about the impact of CBT-I on the daytime correlates of the disorder. A systematic review and narrative synthesis was conducted in order to summarise and evaluate the evidence regarding the impact of CBT-I on cognitive functioning. Reference databases were searched and studies were included if they assessed cognitive performance as an outcome of CBT-I, using either self-report questionnaires or cognitive tests. Eighteen studies met inclusion criteria, comprising 923 individuals with insomnia symptoms. The standardised mean difference was calculated at post-intervention and follow-up. We found preliminary evidence for small to moderate effects of CBT-I on subjective measures of cognitive functioning. Few of the effects were statistically significant, likely due to small sample sizes and limited statistical power. There is a lack of evidence with regards to the impact of CBT-I on objective cognitive performance, primarily due to the small number of studies that administered an objective measure (n = 4). We conclude that adequately powered randomised controlled trials, utilising both subjective and objective measures of cognitive functioning are required. Copyright © 2017 Elsevier Ltd. All rights reserved.
Detection of errant laser beams
NASA Astrophysics Data System (ADS)
Taylor, Arthur F. D. S.; Edwards, Stanley A.; Barrett, J. A.; Bandle, Anthony M.
1990-10-01
The new generation of automated laser machine tools poses problems for those responsible for setting safety standards. While traditional safeguarding will frustrate full exploitation of this hybrid technology, wholesale abandonment of effective containment in favour of safety monitoring and control systems is unlikely to be acceptable. Long term, quantitative risk assessment will resolve this dilemma. Short term, guide lines will have to be derived from practical considerations of the laser facility design, materials, primary safety devices and procedures. Earlier risk assessments are reviewed relative to the emerging perspective of high average power laser installations. Aspects of extended beam delivery systems and equipment utilization and maintenance are examined to assess possible interaction with operational safety and in particular the potential to adversely influence errant laser beam occurrances (ELBO). To satisfy international safety standards for a laser enclosure which offers flexibility and is cost effective a detection system is described which continuously surveys the inside of the enclosure. Extensive trials have been carried out with high average power lasers (up to 10kW) where a range of engineering materials has been exposed to a laser beam. It is shown that the ratio of detection and shut down time to the burn through time can be an acceptable risk and thus indicate which materials will prove adequate.
The Use of Social Media in Orphan Drug Development.
Milne, Christopher-Paul; Ni, Wendi
2017-11-01
Social media has transformed how people interact with one another through the Internet, and it has the potential to do the same for orphan drug development. Currently, social media influences the orphan drug development process in the following three ways: assisting the study of orphan diseases, increasing the awareness of orphan disease, and playing a vital role in clinical trials. However, there are some caveats to the utilization of social media, such as the need to protect patient privacy by adequately de-identifying personal health information, assuring consistent quality and representativeness of the data, and preventing the unblinding of patient group assignments. Social media has both potential for improving orphan drug development and pitfalls, but with proper oversight on the part of companies, support and participation of patients and their advocacy groups, and timely guidance from regulatory authorities, the positives outweigh the negatives for this powerful and patient-centric tool. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.
Van Lieshout, Ryan J.; Schmidt, Louis A.; Dobson, Kathleen G.; Buckley, Norman
2016-01-01
Objective To examine the effectiveness of Audiovisual (AV) interventions at reducing preoperative anxiety and its associated outcomes in children undergoing elective surgery. Methods A systematic review of randomized controlled trials (RCTs) and nonrandomized studies where the primary outcome was children’s preoperative anxiety was conducted. Secondary outcomes included postoperative pain, behavioral changes, recovery, induction compliance, satisfaction, and cost-effectiveness. The risk of bias of each study was assessed. Results In all, 18 studies were identified. A meta-analytic approach and narrative synthesis of findings were used to summarize the results of the studies. Conclusions This systematic review suggests that AV interventions can be effective in reducing children’s preoperative anxiety. Videos, multi-faceted programs, and interactive games appear to be most effective, whereas music therapy and Internet programs are less effective. While AV interventions appear potentially useful, adequately powered RCTs are required to conclusively pinpoint the components and mechanisms of the most effective AV interventions and guide practice. PMID:26476281
Clinical Implications From an Exploratory Study of Postural Management of Breech Presentation
Founds, Sandra A.
2013-01-01
The results from an exploratory study of the effectiveness of maternal knee-chest posture for producing cephalic version of breech presentation are shown. Methods are briefly described and clinical implications are presented. Among 25 women, fewer who performed the maternal knee-chest postural intervention experienced fetal cephalic version than women in the control group who did nothing to influence breech presentation. Despite limitations of the underpowered findings, trends in the data may indicate that parity and gestational age were potentially relevant covariates of version. Postural management is not an evidence-based practice. This exploratory study indicates that maternal knee-chest posture may work opposite to the expected direction, but the small sample size precludes generalizations about efficacy of knee-chest postural management. At least one adequately powered trial that controls for parity and gestational age is needed to determine whether knee-chest postural management results in no effect, a small, or small to moderate clinically significant effect. PMID:16814225
Ragab, S M
2012-10-01
To conduct an adequately powered, prospective, randomised, controlled trial comparing adult dissection tonsillectomy using either ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection. Three hundred patients were randomised into four tonsillectomy technique groups. The operative time, intra-operative bleeding, post-operative pain, tonsillar fossa healing, return to full diet, return to work and post-operative complications were recorded. The bipolar radiofrequency group had a shorter mean operative time. The mean intra-operative blood loss during bipolar radiofrequency tonsillectomy was significantly less compared with cold dissection and ultrasonic scalpel tonsillectomy. Pain scores were significantly higher after bipolar electrocautery tonsillectomy. Patients undergoing bipolar electrocautery tonsillectomy required significantly more days to return to full diet and work. The bipolar electrocautery group showed significantly reduced tonsillar fossa healing during the first and second post-operative weeks. In this adult series, bipolar radiofrequency tonsillectomy was superior to ultrasonic, bipolar electrocautery and cold dissection tonsillectomies. This method combines the advantages of 'hot' and 'cold' tonsillectomy.
[Homocysteine, vitamin B-12, folic acid and the cognitive decline in the elderly].
Smach, M A; Naffeti, S; Charfeddine, B; Ben Abdallah, J; Othmen, L B; Letaef, A; Limem, K
2013-10-01
Hyperhomocysteinemia is a risk factor for neurological diseases, but the underlying pathophysiology has not been adequately explained. Mild hyperhomocysteinemia, which is sometimes associated with a low plasma level of vitamin B9, B12 and folic acid, is responsible in the toxicity in neural cell by activating NMDA receptor. Indeed, even if vitamin supplementation has clearly proven its efficiency on lowering plasma levels of homocysteine, recent studies do not show any positive effect of vitamin therapy on cognitive function. The hypothesis that this therapy is inefficient has been recently reinforced by two randomized trials on the effects of vitamin supplementation. Several hypotheses still need to be explored: Mechanisms of homocysteine toxicity and that of total uselessness of vitamin supplementation; the possible need to complete the actual data with further, more powerful studies in order to prove the role of homocysteine in the development of neurodegenerative diseases and a clinical effect of vitamin therapy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
Becker, Manuel; Klauer, Karl Christoph; Spruyt, Adriaan
2016-02-01
In a series of articles, Spruyt and colleagues have developed the Feature-Specific Attention Allocation framework, stating that the semantic analysis of task-irrelevant stimuli is critically dependent upon dimension-specific attention allocation. In an adversarial collaboration, we replicate one experiment supporting this theory (Spruyt, de Houwer, & Hermans, 2009; Exp. 3), in which semantic priming effects in the pronunciation task were found to be restricted to stimulus dimensions that were task-relevant on induction trials. Two pilot studies showed the capability of our laboratory to detect priming effects in the pronunciation task, but also suggested that the original effect may be difficult to replicate. In this study, we tried to replicate the original experiment while ensuring adequate statistical power. Results show little evidence for dimension-specific priming effects. The present results provide further insight into the malleability of early semantic encoding processes, but also show the need for further research on this topic.
Meta-STEPP: subpopulation treatment effect pattern plot for individual patient data meta-analysis.
Wang, Xin Victoria; Cole, Bernard; Bonetti, Marco; Gelber, Richard D
2016-09-20
We have developed a method, called Meta-STEPP (subpopulation treatment effect pattern plot for meta-analysis), to explore treatment effect heterogeneity across covariate values in the meta-analysis setting for time-to-event data when the covariate of interest is continuous. Meta-STEPP forms overlapping subpopulations from individual patient data containing similar numbers of events with increasing covariate values, estimates subpopulation treatment effects using standard fixed-effects meta-analysis methodology, displays the estimated subpopulation treatment effect as a function of the covariate values, and provides a statistical test to detect possibly complex treatment-covariate interactions. Simulation studies show that this test has adequate type-I error rate recovery as well as power when reasonable window sizes are chosen. When applied to eight breast cancer trials, Meta-STEPP suggests that chemotherapy is less effective for tumors with high estrogen receptor expression compared with those with low expression. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
[Quantitative and qualitative research methods, can they coexist yet?].
Hunt, Elena; Lavoie, Anne-Marise
2011-06-01
Qualitative design is gaining ground in Nursing research. In spite of a relative progress however, the evidence based practice movement continues to dominate and to underline the exclusive value of quantitative design (particularly that of randomized clinical trials) for clinical decision making. In the actual context convenient to those in power making utilitarian decisions on one hand, and facing nursing criticism of the establishment in favor of qualitative research on the other hand, it is difficult to chose a practical and ethical path that values the nursing role within the health care system, keeping us committed to quality care and maintaining researcher's integrity. Both qualitative and quantitative methods have advantages and disadvantages, and clearly, none of them can, by itself, capture, describe and explain reality adequately. Therefore, a balance between the two methods is needed. Researchers bare responsibility to society and science, and they should opt for the appropriate design susceptible to answering the research question, not promote the design favored by the research funding distributors.
Devane, Declan; Lalor, Joan G; Daly, Sean; McGuire, William; Smith, Valerie
2012-02-15
The admission cardiotocograph (CTG) is a commonly used screening test consisting of a short (usually 20 minutes) recording of the fetal heart rate (FHR) and uterine activity performed on the mother's admission to the labour ward. To compare the effects of admission CTG with intermittent auscultation of the FHR on maternal and infant outcomes for pregnant women without risk factors on their admission to the labour ward. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 May 2011) (CENTRAL) (The Cochrane Library 2011 Issue 2 of 4), MEDLINE (1966 to 17 May 2011), CINAHL (1982 to 17 May 2011), Dissertation Abstracts (1980 to 17 May 2011) and the reference list of retrieved papers. All randomised and quasi-randomised trials comparing admission CTG with intermittent auscultation of the FHR for pregnant women between 37 and 42 completed weeks of pregnancy and considered to be at low risk of intrapartum fetal hypoxia and of developing complications during labour. Two authors independently assessed trial eligibility and quality, and extracted data. Data were checked for accuracy. We included four trials involving more than 13,000 women. All four studies included women in labour. Overall, the studies were at low risk of bias. Although not statistically significant using a strict P < 0.05 criterion, data are consistent with women allocated to admission CTG having, on average, a higher probability of an increase in incidence of caesarean section than women allocated to intermittent auscultation (risk ratio (RR) 1.20, 95% confidence interval (CI) 1.00 to 1.44, four trials, 11,338 women, T² = 0.00, I² = 0%). There was no significant difference in the average treatment effect across included trials between women allocated to admission CTG and women allocated to intermittent auscultation in instrumental vaginal birth (RR 1.10, 95% CI 0.95 to 1.27, four trials, 11,338 women, T² = 0.01, I² = 38%) and fetal and neonatal deaths (RR 1.01, 95% CI 0.30 to 3.47, four trials, 11339 infants, T² = 0.00, I² = 0%).Women allocated to admission CTG had, on average, significantly higher rates of continuous electronic fetal monitoring during labour (RR 1.30, 95% CI 1.14 to 1.48, three trials, 10,753 women, T² = 0.01, I² = 79%) and fetal blood sampling (RR 1.28, 95% CI 1.13 to 1.45, three trials, 10,757 women, T² = 0.00, I² = 0%) than women allocated to intermittent auscultation. There were no differences between groups in other secondary outcome measures. Contrary to continued use in some clinical areas, we found no evidence of benefit for the use of the admission cardiotocograph (CTG) for low-risk women on admission in labour.We found no evidence of benefit for the use of the admission CTG for low-risk women on admission in labour. Furthermore, the probability is that admission CTG increases the caesarean section rate by approximately 20%. The data lacked power to detect possible important differences in perinatal mortality. However, it is unlikely that any trial, or meta-analysis, will be adequately powered to detect such differences. The findings of this review support recommendations that the admission CTG not be used for women who are low risk on admission in labour. Women should be informed that admission CTG is likely associated with an increase in the incidence of caesarean section without evidence of benefit.
Recommended high-tank temperatures for maintenance of high-tank backup support, Revision 3
DOE Office of Scientific and Technical Information (OSTI.GOV)
Greager, O.H.
1964-05-20
Purpose of this note is to recommend revised curves for the high-tank temperature required to maintain adequate high-tank backup support at the six small reactors. Compliance with the conditions shown on these curves will ensure adequate high-tank flow rates following the simultaneous loss of electric and steam power.
Challenging oral contraception after weight loss by bariatric surgery.
Merhi, Zaher O
2007-01-01
As surgical weight loss becomes more commonly performed in fertile women, adequate contraception is more frequently becoming an issue. The purpose of this article is to appraise the literature to ascertain whether the use of oral contraception is effective and adequate after bariatric surgery. The literature search revealed that the combination of lower oral contraception dosages and surgical gastrointestinal disturbances might place patients at higher risks of unintended pregnancy. Until clinical trials show its efficacy, physicians should use oral contraception with prudence after bariatric surgery. 2007 S. Karger AG, Basel
Massage therapy for children with autism spectrum disorders: a systematic review.
Lee, Myeong Soo; Kim, Jong-In; Ernst, Edzard
2011-03-01
We aimed to assess the effectiveness of massage as a treatment option for autism. We searched the following electronic databases using the time of their inception through March 2010: MEDLINE, AMED, CINAHL, EMBASE, PsycINFO, Health Technology Assessment, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Psychology and Behavioral Sciences Collection, 6 Korean medical databases (KSI, DBpia, KISTEP, RISS, KoreaMed, and National Digital Library), China Academic Journal (through China National Knowledge Infrastructure), and 3 Japanese medical databases (Journal@rchive, Science Links Japan, and Japan Science & Technology link). The search phrase used was "(massage OR touch OR acupressure) AND (autistic OR autism OR Asperger's syndrome OR pervasive developmental disorder)." The references in all located articles were also searched. No language restrictions were imposed. Prospective controlled clinical studies of any type of massage therapy for autistic patients were included. Trials in which massage was part of a complex intervention were also included. Case studies, case series, qualitative studies, uncontrolled trials, studies that failed to provide detailed results, and trials that compared one type of massage with another were excluded. All articles were read by 2 independent reviewers (M.S.L. and J-I.K.), who extracted data from the articles according to predefined criteria. Risk of bias was assessed using the Cochrane classification. Of 132 articles, only 6 studies met our inclusion criteria. One randomized clinical trial found that massage plus conventional language therapy was superior to conventional language therapy alone for symptom severity (P < .05) and communication attitude (P < .01). Two randomized clinical trials reported a significant benefit of massage for sensory profile (P < .01), adaptive behavior (P < .05), and language and social abilities (P < .01) as compared with a special education program. The fourth randomized clinical trial showed beneficial effects of massage for social communication (P < .05). Two nonrandomized controlled clinical trials suggested that massage therapy is effective. However, all of the included trials have high risk of bias. The main limitations of the included studies were small sample sizes, predefined primary outcome measures, inadequate control for nonspecific effects, and a lack of power calculations or adequate follow-up. Limited evidence exists for the effectiveness of massage as a symptomatic treatment of autism. Because the risk of bias was high, firm conclusions cannot be drawn. Future, more rigorous randomized clinical trials seem to be warranted. © Copyright 2011 Physicians Postgraduate Press, Inc.
Comparative study of outcome measures and analysis methods for traumatic brain injury trials.
Alali, Aziz S; Vavrek, Darcy; Barber, Jason; Dikmen, Sureyya; Nathens, Avery B; Temkin, Nancy R
2015-04-15
Batteries of functional and cognitive measures have been proposed as alternatives to the Extended Glasgow Outcome Scale (GOSE) as the primary outcome for traumatic brain injury (TBI) trials. We evaluated several approaches to analyzing GOSE and a battery of four functional and cognitive measures. Using data from a randomized trial, we created a "super" dataset of 16,550 subjects from patients with complete data (n=331) and then simulated multiple treatment effects across multiple outcome measures. Patients were sampled with replacement (bootstrapping) to generate 10,000 samples for each treatment effect (n=400 patients/group). The percentage of samples where the null hypothesis was rejected estimates the power. All analytic techniques had appropriate rates of type I error (≤5%). Accounting for baseline prognosis either by using sliding dichotomy for GOSE or using regression-based methods substantially increased the power over the corresponding analysis without accounting for prognosis. Analyzing GOSE using multivariate proportional odds regression or analyzing the four-outcome battery with regression-based adjustments had the highest power, assuming equal treatment effect across all components. Analyzing GOSE using a fixed dichotomy provided the lowest power for both unadjusted and regression-adjusted analyses. We assumed an equal treatment effect for all measures. This may not be true in an actual clinical trial. Accounting for baseline prognosis is critical to attaining high power in Phase III TBI trials. The choice of primary outcome for future trials should be guided by power, the domain of brain function that an intervention is likely to impact, and the feasibility of collecting outcome data.
Comparative Study of Outcome Measures and Analysis Methods for Traumatic Brain Injury Trials
Alali, Aziz S.; Vavrek, Darcy; Barber, Jason; Dikmen, Sureyya; Nathens, Avery B.
2015-01-01
Abstract Batteries of functional and cognitive measures have been proposed as alternatives to the Extended Glasgow Outcome Scale (GOSE) as the primary outcome for traumatic brain injury (TBI) trials. We evaluated several approaches to analyzing GOSE and a battery of four functional and cognitive measures. Using data from a randomized trial, we created a “super” dataset of 16,550 subjects from patients with complete data (n=331) and then simulated multiple treatment effects across multiple outcome measures. Patients were sampled with replacement (bootstrapping) to generate 10,000 samples for each treatment effect (n=400 patients/group). The percentage of samples where the null hypothesis was rejected estimates the power. All analytic techniques had appropriate rates of type I error (≤5%). Accounting for baseline prognosis either by using sliding dichotomy for GOSE or using regression-based methods substantially increased the power over the corresponding analysis without accounting for prognosis. Analyzing GOSE using multivariate proportional odds regression or analyzing the four-outcome battery with regression-based adjustments had the highest power, assuming equal treatment effect across all components. Analyzing GOSE using a fixed dichotomy provided the lowest power for both unadjusted and regression-adjusted analyses. We assumed an equal treatment effect for all measures. This may not be true in an actual clinical trial. Accounting for baseline prognosis is critical to attaining high power in Phase III TBI trials. The choice of primary outcome for future trials should be guided by power, the domain of brain function that an intervention is likely to impact, and the feasibility of collecting outcome data. PMID:25317951
Pin site care for preventing infections associated with external bone fixators and pins.
Lethaby, Anne; Temple, Jenny; Santy-Tomlinson, Julie
2013-12-03
Metal pins are used to apply skeletal traction or external fixation devices in the management of orthopaedic fractures. These percutaneous pins protrude through the skin, and the way in which they are treated after insertion may affect the incidence of pin site infection. This review set out to summarise the evidence of pin site care on infection rates. To assess the effect on infection rates of different methods of cleansing and dressing orthopaedic percutaneous pin sites. In September 2013, for this third update, we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We evaluated all randomised controlled trials (RCTs) that compared the effect on infection and other complication rates of different methods of cleansing or dressing orthopaedic percutaneous pin sites. Two review authors independently assessed the citations retrieved by the search strategies for reports of relevant RCTs, then independently selected trials that satisfied the inclusion criteria, extracted data and undertook quality assessment. A total of eleven trials (572 participants) were eligible for inclusion in the review but not all participants contributed data to each comparison. Three trials compared a cleansing regimen (saline, alcohol, hydrogen peroxide or antibacterial soap) with no cleansing (application of a dry dressing), three trials compared alternative sterile cleansing solutions (saline, alcohol, peroxide, povidone iodine), three trials compared methods of cleansing (one trial compared identical pin site care performed daily or weekly and the two others compared sterile with non sterile techniques), one trial compared daily pin site care with no care and six trials compared different dressings (using different solutions/ointments and dry and impregnated gauze or sponges). One small blinded study of 38 patients found that the risk of pin site infection was significantly reduced with polyhexamethylene biguanide (PHMB) gauze when compared to plain gauze (RR 0.23, 95% CI 0.12 to 0.44) (infection rate of 1% in the PHMB group and 4.5% in the control group) but this study was at high risk of bias as the unit of analysis was observations rather than patients. There were no other statistically significant differences between groups in any of the other trials. The available trial evidence was not extensive, was very heterogeneous and generally of poor quality, so there was insufficient evidence to be able to identify a strategy of pin site care that minimises infection rates. Adequately-powered randomised trials are required to examine the effects of different pin care regimens, and co-interventions - such as antibiotic use - and other extraneous factors must be controlled in the study designs.
Hussein, Norita; Weng, Stephen F; Kai, Joe; Kleijnen, Jos; Qureshi, Nadeem
2015-08-12
Globally, about five per cent of children are born with congenital or genetic disorders. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in specific patient populations. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if genetic counselling is only offered in an antenatal setting. To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 25 June 2015.Date of latest search of all other sources: 10 December 2014. Any randomised or quasi-randomised control trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care. We identified 19 papers, describing 13 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found. No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found. As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.
Feasibility of Image-Guided Transthoracic Core Needle Biopsy in the BATTLE Lung Trial
Tam, Alda L.; Kim, Edward S.; Lee, J. Jack; Ensor, Joe E.; Hicks, Marshall E.; Tang, Ximing; Blumenschein, George R.; Alden, Christine M.; Erasmus, Jeremy J.; Tsao, Anne; Lippman, Scott M.; Hong, Waun K.; Wistuba, Ignacio I.; Gupta, Sanjay
2013-01-01
Purpose As therapy for non-small cell lung cancer (NSCLC) patients becomes more personalized, additional tissue in the form of core needle biopsies (CNBs) for biomarker analysis is increasingly required for determining appropriate treatment and for enrollment into clinical trials. We report our experience with small-caliber percutaneous transthoracic (PT) CNBs for the evaluation of multiple molecular biomarkers in BATTLE (Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination), a personalized, targeted therapy NSCLC clinical trial. Methods The medical records of patients who underwent PTCNB for consideration of enrollment in BATTLE, were reviewed for diagnostic yield of 11 predetermined molecular markers, and procedural complications. Univariate and multivariate analyses of factors related to patient and lesion characteristics were performed to determine possible influences on diagnostic yield. Results One hundred and seventy PTCNBs were performed using 20-gauge biopsy needles in 151 NSCLC patients screened for the trial. 82.9% of the biopsy specimens were found to have adequate tumor tissue for analysis of the required biomarkers. On multivariate analysis, metastatic lesions were 5.4 times more likely to yield diagnostic tissue as compared to primary tumors (p = 0.0079). Pneumothorax and chest tube insertion rates were 15.3% and 9.4%, respectively. Conclusions Image-guided 20-gauge PTCNB is safe and provides adequate tissue for analysis of multiple biomarkers in the majority of patients being considered for enrollment into a personalized, targeted therapy NSCLC clinical trial. Metastatic lesions are more likely to yield diagnostic tissue as compared to primary tumors. PMID:23442309
Schmitt, Jochen; Spuls, Phyllis I; Thomas, Kim S; Simpson, Eric; Furue, Masutaka; Deckert, Stefanie; Dohil, Magdalene; Apfelbacher, Christian; Singh, Jasvinder A; Chalmers, Joanne; Williams, Hywel C
2014-10-01
The lack of core outcome sets for atopic eczema (AE) is a major obstacle for advancing evidence-based treatment. The global Harmonising Outcome Measures for Eczema (HOME) initiative has already defined clinical signs, symptoms, quality of life, and long-term control of flares as core outcome domains for AE trials. This article deals with the standardization of measurement instruments to assess clinical signs of AE. To resolve the current lack of standardization of the assessment of clinical signs of AE, we followed a structured process of systematic reviews and international consensus sessions to identify 1 core outcome measurement instrument for assessment of clinical signs in all future AE trials. Systematic reviews indicated that from 16 different instruments identified to assess clinical signs of AE, only the Eczema Area and Severity Index (EASI) and the objective Scoring Atopic Dermatitis (SCORAD) index were identified as extensively validated. The EASI has adequate validity, responsiveness, internal consistency, and intraobserver reliability. The objective SCORAD index has adequate validity, responsiveness, and interobserver reliability but unclear intraobserver reliability to measure clinical signs of AE. In an international consensus study, patients, physicians, nurses, methodologists, and pharmaceutical industry representatives agreed that the EASI is the preferred core instrument to measure clinical signs in all future AE trials. All stakeholders involved in designing, reporting, and using clinical trials on AE are asked to comply with this consensus to enable better evidence-based decision making, clearer scientific communication, and improved patient care. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Yao, Chu K; Gibson, Peter R; Shepherd, Susan J
2013-05-01
Clear guiding principles for the design and conduct of dietary intervention trials in functional gastrointestinal disorders (FGID) are lacking. This narrative review examines the specific challenges associated with the design and reporting in dietary intervention trials. Dietary intervention trials need to address the collinearity between food, nutrients, and bioactive components that obscure the relationship between food and their effects in the gut. Randomized, double-blinded, placebo-controlled studies remain the gold standard for dietary trials, but are limited by difficulties in adequate masking of study food or inappropriate choice of placebo food/diets. Provision of study diets as the preferred delivery method can somewhat address these limitations, although allowing good adherence compared with education-based dietary interventions. Issues associated with participant expectancies and dietary behaviors can alter the true effectiveness of a diet. In addition, failure to adjust for or report baseline intake of nutrients of interest can reduce their magnitude of benefit. Bias in subjective reports and choice of measurement tools can preclude accurate assessment of food-intake data. In the design of elimination and rechallenge studies, sufficient time period and adequate exclusion of dietary triggers are essential to ensure symptoms are well-controlled before rechallenging. The route and frequency of challenging, design of test food, and/or placebo should match the aims of the rechallenge phase. Long-term efficacy data of such therapeutic diets has been poorly documented in most studies. Standardized guidelines that address many of the challenges outlined above are suggested to strengthen the quality of evidence for dietary therapies in FGID.
Lansberg, Maarten G; Bhat, Ninad S; Yeatts, Sharon D; Palesch, Yuko Y; Broderick, Joseph P; Albers, Gregory W; Lai, Tze L; Lavori, Philip W
2016-12-01
Adaptive trial designs that allow enrichment of the study population through subgroup selection can increase the chance of a positive trial when there is a differential treatment effect among patient subgroups. The goal of this study is to illustrate the potential benefit of adaptive subgroup selection in endovascular stroke studies. We simulated the performance of a trial design with adaptive subgroup selection and compared it with that of a traditional design. Outcome data were based on 90-day modified Rankin Scale scores, observed in IMS III (Interventional Management of Stroke III), among patients with a vessel occlusion on baseline computed tomographic angiography (n=382). Patients were categorized based on 2 methods: (1) according to location of the arterial occlusive lesion and onset-to-randomization time and (2) according to onset-to-randomization time alone. The power to demonstrate a treatment benefit was based on 10 000 trial simulations for each design. The treatment effect was relatively homogeneous across categories when patients were categorized based on arterial occlusive lesion and time. Consequently, the adaptive design had similar power (47%) compared with the fixed trial design (45%). There was a differential treatment effect when patients were categorized based on time alone, resulting in greater power with the adaptive design (82%) than with the fixed design (57%). These simulations, based on real-world patient data, indicate that adaptive subgroup selection has merit in endovascular stroke trials as it substantially increases power when the treatment effect differs among subgroups in a predicted pattern. © 2016 American Heart Association, Inc.
The provision of therapy mattresses for pressure ulcer prevention.
Pagnamenta, Fania
2017-03-23
Preventing pressure ulcers is complex and involves skin care, the provision of therapy mattresses, repositioning, the management of incontinence and adequate nutritional support. This article describes a model of therapy mattress provision that is based on non-powered products. Evaluating the efficiency of this model is challenging, due to the complexities of care, but Safety Thermometer data and incidents reports offer reassurance that non-powered therapy mattresses can provide adequate pressure ulcer prevention. Therapy mattress provision is only one of the five interventions and these are described in details to give readers a fuller picture of the model used at the author's trust.
Moyers, M F
2014-06-01
Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCTNs) to relative linear stopping powers (RLSPs). Various facilities engaged in multi-institutional clinical trials involving proton beams have been applying significantly different margins in their patient planning. This study was performed to determine the variance in the conversion functions used at proton facilities in the U.S.A. wishing to participate in National Cancer Institute sponsored clinical trials. A simplified method of determining the conversion function was developed using a standard phantom containing only water and aluminum. The new method was based on the premise that all scanners have their XCTNs for air and water calibrated daily to constant values but that the XCTNs for high density/high atomic number materials are variable with different scanning conditions. The standard phantom was taken to 10 different proton facilities and scanned with the local protocols resulting in 14 derived conversion functions which were compared to the conversion functions used at the local facilities. For tissues within ±300 XCTN of water, all facility functions produced converted RLSP values within ±6% of the values produced by the standard function and within 8% of the values from any other facility's function. For XCTNs corresponding to lung tissue, converted RLSP values differed by as great as ±8% from the standard and up to 16% from the values of other facilities. For XCTNs corresponding to low-density immobilization foam, the maximum to minimum values differed by as much as 40%. The new method greatly simplifies determination of the conversion function, reduces ambiguity, and in the future could promote standardization between facilities. Although it was not possible from these experiments to determine which conversion function is most appropriate, the variation between facilities suggests that the margins used in some facilities to account for the uncertainty in converting XCTNs to RLSPs may be too small.
Hypothesis testing in clinical trials.
Green, S B
2000-08-01
In designing and analyzing any clinical trial, two issues related to patient heterogeneity must be considered: (1) the effect of chance and (2) the effect of bias. These issues are addressed by enrolling adequate numbers of patients in the study and using randomization for treatment assignment. An "intention-to-treat" analysis of outcome data includes all individuals randomized and counted in the group to which they are randomized. There is an increased risk of spurious results with a greater number of subgroup analyses, particularly when these analyses are data derived. Factorial designs are sometimes appropriate and can lead to efficiencies by addressing more than one comparison of interventions in a single trial.
Estimating statistical power for open-enrollment group treatment trials.
Morgan-Lopez, Antonio A; Saavedra, Lissette M; Hien, Denise A; Fals-Stewart, William
2011-01-01
Modeling turnover in group membership has been identified as a key barrier contributing to a disconnect between the manner in which behavioral treatment is conducted (open-enrollment groups) and the designs of substance abuse treatment trials (closed-enrollment groups, individual therapy). Latent class pattern mixture models (LCPMMs) are emerging tools for modeling data from open-enrollment groups with membership turnover in recently proposed treatment trials. The current article illustrates an approach to conducting power analyses for open-enrollment designs based on the Monte Carlo simulation of LCPMM models using parameters derived from published data from a randomized controlled trial comparing Seeking Safety to a Community Care condition for women presenting with comorbid posttraumatic stress disorder and substance use disorders. The example addresses discrepancies between the analysis framework assumed in power analyses of many recently proposed open-enrollment trials and the proposed use of LCPMM for data analysis. Copyright © 2011 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Spybrook, Jessaca; Hedges, Larry; Borenstein, Michael
2014-01-01
Research designs in which clusters are the unit of randomization are quite common in the social sciences. Given the multilevel nature of these studies, the power analyses for these studies are more complex than in a simple individually randomized trial. Tools are now available to help researchers conduct power analyses for cluster randomized…
ERIC Educational Resources Information Center
Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben
2016-01-01
The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…
Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim
2016-03-01
Recent studies have demonstrated that prestimulus alpha-band activity substantially influences perception of near-threshold stimuli. Here, we studied the influence of prestimulus alpha power fluctuations on temporal perceptual discrimination of suprathreshold tactile stimuli and subjects' confidence regarding their perceptual decisions. We investigated how prestimulus alpha-band power influences poststimulus decision-making variables. We presented electrical stimuli with different stimulus onset asynchronies (SOAs) to human subjects, and determined the SOA for which temporal perceptual discrimination varied on a trial-by-trial basis between perceiving 1 or 2 stimuli, prior to recording brain activity with magnetoencephalography. We found that low prestimulus alpha power in contralateral somatosensory and occipital areas predicts the veridical temporal perceptual discrimination of 2 stimuli. Additionally, prestimulus alpha power was negatively correlated with confidence ratings in correctly perceived trials, but positively correlated for incorrectly perceived trials. Finally, poststimulus event-related fields (ERFs) were modulated by prestimulus alpha power and reflect the result of a decisional process rather than physical stimulus parameters around ∼150 ms. These findings provide new insights into the link between spontaneous prestimulus alpha power fluctuations, temporal perceptual discrimination, decision making, and decisional confidence. The results suggest that prestimulus alpha power modulates perception and decisions on a continuous scale, as reflected in confidence ratings. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Linke, Richard; Ulrich, Frank; Bechstein, Wolf O; Schnitzbauer, Andreas A
2015-01-01
Bile leakage testing may help to detect and reduce the incidence of biliary leakage after hepatic resection. This review was performed to investigate the value of the White-test in identifying intraoperative biliary leakage and avoiding postoperative leakage. A systematic review and meta-analysis was performed. Two researchers performed literature research. Primary outcome measure was the incidence of post-hepatectomy biliary leakage; secondary outcome measure was the ability of detecting intraoperative biliary leakage with the help of the White-test. A total of 4 publications (including original data from our center) were included in the analysis. Evidence levels of the included studies had medium quality of 2b (individual cohort studies including low quality randomized controlled trials). Use of the White-test led to a significant reduction of post-operative biliary leakage [OR: 0.3 (95% CI: 0.14, 0.63), p = 0.002] and led to a significant higher intraoperative detection of biliary leakages [OR: 0.03 (95%CI: 0.02, 0.07), p < 0.00001]. Existing evidence implicates the use of the White-test after hepatic resection to identify bile leaks intraoperatively and thus reduce incidence of post-operative biliary leakage. Nonetheless, there is a requirement for a high-quality randomized controlled trial with adequately powered sample-size to confirm findings from the above described studies and further increase evidence in this field.
Cold therapy to prevent paclitaxel-induced peripheral neuropathy.
Griffiths, Claire; Kwon, Nancy; Beaumont, Jennifer L; Paice, Judith A
2018-04-21
This case-control study was designed to assess the efficacy of cryotherapy to prevent paclitaxel-induced painful peripheral neuropathy in women with breast cancer. Participants served as their own paired control, with randomization of the cooled glove/sock to either the dominant or the non-dominant hand/foot, worn for 15 min prior to, during, and 15 min after completion of the paclitaxel infusion. Outcome measures included the Neuropathic Pain Symptom Inventory, the Brief Pain Inventory, and quantitative sensory testing. Data were measured at each of six time points-baseline, post-treatment (approximately 2 weeks after the last paclitaxel infusion), and at the first, fifth, ninth, and final weekly paclitaxel treatments. Of 29 randomized participants, 20 (69%) received at least one cryotherapy treatment, and 11 (38%) received all four cryotherapy treatments. Ten (34%) participants could not tolerate the cryotherapy, and six (21%) declined further participation at some point during the trial. Only seven participants (24%) were available for the final post-chemotherapy QST and questionnaires. There were no significant differences in measures of neuropathy or pain between treated and untreated hands or feet. Strategies to prevent painful peripheral neuropathy are urgently needed. In this current trial, dropout due to discomfort precluded adequate power to fully understand the potential benefits of cryotherapy. Much more research is needed to discover safe and effective preventive strategies that can be easily implemented within busy infusion centers.
Efficacy and safety of miconazole for oral candidiasis: a systematic review and meta-analysis.
Zhang, L-W; Fu, J-Y; Hua, H; Yan, Z-M
2016-04-01
The objective of this study is to assess the efficacy and safety of miconazole for treating oral candidiasis. Twelve electronic databases were searched for randomized controlled trials evaluating treatments for oral candidiasis and complemented by hand searching. The clinical and mycological outcomes, as well as adverse effects, were set as the primary outcome criteria. Seventeen trials were included in this review. Most studies were considered to have a high or moderate level of bias. Miconazole was more effective than nystatin for thrush. For HIV-infected patients, there was no significant difference in the efficacy between miconazole and other antifungals. For denture wearers, microwave therapy was significantly better than miconazole. No significant difference was found in the safety evaluation between miconazole and other treatments. The relapse rate of miconazole oral gel may be lower than that of other formulations. This systematic review and meta-analysis indicated that miconazole may be an optional choice for thrush. Microwave therapy could be an effective adjunct treatment for denture stomatitis. Miconazole oral gel may be more effective than other formulations with regard to long-term results. However, future studies that are adequately powered, large-scale, and well-designed are needed to provide higher-quality evidence for the management of oral candidiasis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Community-based physical activity interventions among women: a systematic review
Amiri Farahani, Leila; Asadi-Lari, Mohsen; Mohammadi, Eesa; Parvizy, Soroor; Haghdoost, Ali Akbar; Taghizadeh, Ziba
2015-01-01
Objective Review and assess the effectiveness of community-based physical activity interventions among women aged 18–65 years. Design Systematic review Methods To find relevant articles, the researcher selected reports published in English between 1 January 2000 and 31 March 2013. Systematic search was to find controlled-trial studies that were conducted to uncover the effect of community-based interventions to promote physical activity among women 18–65 years of age, in which physical activity was reported as one of the measured outcomes. The methodological quality assessment was performed using a critical appraisal sheet. Also, the levels of evidence were assessed for the types of interventions. Results The literature search identified nine articles. Four of the studies were randomised and the others studies had high methodological quality. There was no evidence, on the basis of effectiveness, for social cognitive theory-based interventions and inconclusive evidence of effectiveness for the rest of interventions. Conclusions There is insufficient evidence to assess the effectiveness of community-based interventions for enhancing physical activity among women. There is a need for high-quality randomised clinical trials with adequate statistical power to determine whether multicomponent and community-based intervention programmes increase physical activity among women, as well as to determine what type of interventions have a more effective and sustainable impact on women's physical activity. PMID:25833668
Split-mouth design in Paediatric Dentistry clinical trials.
Pozos-Guillén, A; Chavarría-Bolaños, D; Garrocho-Rangel, A
2017-03-01
The aim of this article was to describe the essential concepts of the split-mouth design, its underlying assumptions, advantages, limitations, statistical considerations, and possible applications in Paediatric Dentistry clinical investigation. In Paediatric Dentistry clinical investigation, and as part of randomised controlled trials, the split-mouth design is commonly used. The design is characterised by subdividing the child's dentition into halves (right and left), where two different treatment modalities are assigned to one side randomly, in order to allow further outcome evaluation. Each participant acts as their own control by making within- patient rather than between-patient comparisons, thus diminishing inter-subject variability and increasing study accuracy and power. However, the main problem with this design comprises the potential contamination of the treatment effect from one side to the other, or the "carry-across effect"; likewise, this design is not indicated when the oral disease to be treated is not symmetrically distributed (e.g. severity) in the mouth of children. Thus, in spite of its advantages, the split-mouth design can only be applied in a limited number of strictly selected cases. In order to obtain valid and reliable data from split mouth design studies, it is necessary to evaluate the risk of carry-across effect as well as to carefully analise and select adequate inclusion criteria, sample-size calculation and method of statistical analysis.
Daykin, Anne; Selman, Lucy E; Cramer, Helen; McCann, Sharon; Shorter, Gillian W; Sydes, Matthew R; Gamble, Carrol; Macefield, Rhiannon; Lane, J Athene; Shaw, Alison
2017-12-22
The oversight and conduct of a randomised controlled trial involves several stakeholders, including a Trial Steering Committee (TSC), Trial Management Group (TMG), Data Monitoring Committee (DMC), funder and sponsor. We aimed to examine how the relationships between these stakeholders affect the trial oversight process and its rigour, to inform future revision of Good Clinical Practice guidelines. Using an ethnographic study design, we observed the oversight processes of eight trials and conducted semi-structured interviews with members of the trials' TSCs and TMGs, plus other relevant informants, including sponsors and funders of trials. Data were analysed thematically, and findings triangulated and integrated to give a multi-perspective account of current oversight practices in the UK. Eight TSC and six TMG meetings from eight trials were observed and audio-recorded, and 66 semi-structured interviews conducted with 52 purposively sampled key informants. Five themes are presented: (1) Collaboration within the TMG and role of the CTU; (2) Collaboration and conflict between oversight committees; (3) Priorities; (4) Communication between trial oversight groups and (5) Power and accountability. There was evidence of collaborative relationships, based on mutual respect, between CTUs, TMGs and TSCs, but also evidence of conflict. Relationships between trial oversight committees were influenced by stakeholders' priorities, both organisational and individual. Good communication following specific, recognised routes played a central role in ensuring that relationships were productive and trial oversight efficient. Participants described the possession of power over trials as a shifting political landscape, and there was lack of clarity regarding the roles and accountability of each committee, the sponsor and funder. Stakeholders' perceptions of their own power over a trial, and the power of others, influenced relationships between those involved in trial oversight. Recent developments in trial design and conduct have been accompanied by changes in roles and relationships between trial oversight groups. Recognising and respecting the value of differing priorities among those involved in running trials is key to successful relationships between committees, funders and sponsors. Clarity regarding appropriate lines of communication, roles and accountability is needed. We present 10 evidence-based recommendations to inform updates to international trial guidance, particularly the Medical Research Council guidelines.
Shenoy, Erica S.; Huang, Mingshu; Kuhlen, James L.; Ware, Winston A.; Parker, Robert A.; Walensky, Rochelle P.
2016-01-01
Background Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. Objective To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Design Retrospective cohort. Participants Adult inpatients with MSSA bacteremia, January 2009 through October 2013. Main Measures The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Key Results Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Conclusions Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients. PMID:27438379
Blumenthal, Kimberly G; Shenoy, Erica S; Huang, Mingshu; Kuhlen, James L; Ware, Winston A; Parker, Robert A; Walensky, Rochelle P
2016-01-01
Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Retrospective cohort. Adult inpatients with MSSA bacteremia, January 2009 through October 2013. The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.
Comparison of Time-to-First Event and Recurrent Event Methods in Randomized Clinical Trials.
Claggett, Brian; Pocock, Stuart; Wei, L J; Pfeffer, Marc A; McMurray, John J V; Solomon, Scott D
2018-03-27
Background -Most Phase-3 trials feature time-to-first event endpoints for their primary and/or secondary analyses. In chronic diseases where a clinical event can occur more than once, recurrent-event methods have been proposed to more fully capture disease burden and have been assumed to improve statistical precision and power compared to conventional "time-to-first" methods. Methods -To better characterize factors that influence statistical properties of recurrent-events and time-to-first methods in the evaluation of randomized therapy, we repeatedly simulated trials with 1:1 randomization of 4000 patients to active vs control therapy, with true patient-level risk reduction of 20% (i.e. RR=0.80). For patients who discontinued active therapy after a first event, we assumed their risk reverted subsequently to their original placebo-level risk. Through simulation, we varied a) the degree of between-patient heterogeneity of risk and b) the extent of treatment discontinuation. Findings were compared with those from actual randomized clinical trials. Results -As the degree of between-patient heterogeneity of risk was increased, both time-to-first and recurrent-events methods lost statistical power to detect a true risk reduction and confidence intervals widened. The recurrent-events analyses continued to estimate the true RR=0.80 as heterogeneity increased, while the Cox model produced estimates that were attenuated. The power of recurrent-events methods declined as the rate of study drug discontinuation post-event increased. Recurrent-events methods provided greater power than time-to-first methods in scenarios where drug discontinuation was ≤30% following a first event, lesser power with drug discontinuation rates of ≥60%, and comparable power otherwise. We confirmed in several actual trials in chronic heart failure that treatment effect estimates were attenuated when estimated via the Cox model and that increased statistical power from recurrent-events methods was most pronounced in trials with lower treatment discontinuation rates. Conclusions -We find that the statistical power of both recurrent-events and time-to-first methods are reduced by increasing heterogeneity of patient risk, a parameter not included in conventional power and sample size formulas. Data from real clinical trials are consistent with simulation studies, confirming that the greatest statistical gains from use of recurrent-events methods occur in the presence of high patient heterogeneity and low rates of study drug discontinuation.
Egbewale, Bolaji E; Lewis, Martyn; Sim, Julius
2014-04-09
Analysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data. 126 hypothetical trial scenarios were evaluated (126,000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario. Compared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect. Across a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power.
2014-01-01
Background Analysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data. Methods 126 hypothetical trial scenarios were evaluated (126 000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario. Results Compared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect. Conclusions Across a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power. PMID:24712304
Christenson, Jim; Nafziger, Sarah; Compton, Scott; Vijayaraghavan, Kris; Slater, Brian; Ledingham, Robert; Powell, Judy; McBurnie, Mary Ann
2009-01-01
Background The time to skill deterioration between primary training/retraining and further retraining in Cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) Trial was a multi-center randomized controlled trial evaluating survival after CPR-only vs. CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest. Aims This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation. Methods Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate vs not adequate) using Chi-square tests for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders. Results The proportion of volunteers judged to be competent did not diminish by interval (3,6,9,12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals before to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores. Conclusions After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to one year. AED skills do not significantly deteriorate and 90% of volunteers remain competent up to one year. PMID:17303309
Quality of full and final publications reporting acute stroke trials: a systematic review.
Bath, F J; Owen, V E; Bath, P M
1998-10-01
Several studies have shown that the quality of reporting of trials throughout medicine is variable and often poor. We report on the quality of the final reports of randomized controlled trials (RCTs) of drug therapies assessed in acute stroke. English-language reports published up to the end of 1996 relating to completed RCTs in acute stroke were identified from electronic searches of the Cochrane Stroke Review Group database of stroke trials and the Cochrane Controlled Trials Register (CD-ROM issue 1, 1997, of the Cochrane Library). Report quality was assessed with the 33 criteria of the CONSORT statement and 53 additional factors relevant to acute stroke or trials in general. Trial quality was also assessed with a 7-point scale. Up to 1996, 114 RCTs were published which involved 20 536 patients (median, 80; range, 16 to 1267 per trial); 39 (35.5%) of these were published in Stroke. The median total report quality was 40/86 (range, 15 to 61) for all criteria and 19/33 (range, 9 to 29) for the CONSORT criteria alone. Although adequate information was given in the introduction and discussion sections of most reports, insufficient details were given on methods, assignment of patients to treatment groups, statistical analyses, the prevalence of risk factors, and assessment of outcomes. Report quality has improved between 1956 and 1996 (Spearman correlation coefficient [rs], 0.575; 95% confidence interval [CI], 0. 439 to 0.685) and was superior in large trials (rs=0.434; 95% CI, 0. 274 to 0.571). Although report quality was related to trial quality (rs=0.675; 95% CI, 0.563 to 0.763), it was not related to journal impact factor (rs=0.170; 95% CI, -0.015 to 0.344). Trials with a positive outcome tended to be less well reported than those with a neutral or negative outcome (rs=-0.192; 95% CI, -0.351 to -0.011). The overall quality of study reports for parallel group RCTs in acute stroke is poor but appears to be improving with time and in parallel with an increase in trial size. Reports often lack detailed information on the methods of randomization, concealment of allocation, and statistical analysis, all factors which can, if undertaken poorly, affect trial results and validity. It is vital that future trials are adequately reported; we believe that authors should follow the CONSORT guidelines and that referees and editors should ensure this happens.
Influence of environmental temperature on 40 km cycling time-trial performance.
Peiffer, Jeremiah J; Abbiss, Chris R
2011-06-01
The purpose of this study was to examine the effect of environmental temperature on variability in power output, self-selected pacing strategies, and performance during a prolonged cycling time trial. Nine trained male cyclists randomly completed four 40 km cycling time trials in an environmental chamber at 17°C, 22°C, 27°C, and 32°C (40% RH). During the time trials, heart rate, core body temperature, and power output were recorded. The variability in power output was assessed with the use of exposure variation analysis. Mean 40 km power output was significantly lower during 32°C (309 ± 35 W) compared with 17°C (329 ± 31 W), 22°C (324 ± 34 W), and 27°C (322 ± 32 W). In addition, greater variability in power production was observed at 32°C compared with 17°C, as evidenced by a lower (P = .03) standard deviation of the exposure variation matrix (2.9 ± 0.5 vs 3.5 ± 0.4 units, respectively). Core temperature was greater (P < .05) at 32°C compared with 17°C and 22°C from 30 to 40 km, and the rate of rise in core temperature throughout the 40 km time trial was greater (P < .05) at 32°C (0.06 ± 0.04°C·km-1) compared with 17°C (0.05 ± 0.05°C·km-1). This study showed that time-trial performance is reduced under hot environmental conditions, and is associated with a shift in the composition of power output. These finding provide insight into the control of pacing strategies during exercise in the heat.
Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan; Holan, Scott; Ellerseick, Mark
2010-01-01
As with all large rivers in the United States, the Missouri River has been altered, with approximately 32.5 percent of the main stem length impounded and 32.5 percent channelized. These physical alterations to the environment have had effects on the fisheries, but studies examining the effects of alterations have been localized and for short periods of time. In response to the U.S. Fish and Wildlife Service biological opinion, the U.S. Army Corps of Engineers initiated monitoring of the fish community of the Missouri River in 2003. The goal of the Pallid Sturgeon Population Assessment Program is to provide information to detect changes in populations and habitat preferences with time for pallid sturgeon (Scaphirhynchus albus) and native target species in the Missouri River Basin. To determine statistical power of the Pallid Sturgeon Population Assessment Program, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first 3 years of data (2003 to 2005). In cases where 3 years of data were unavailable, estimates were obtained using those data. It was determined that at least 20 years of data, sampling 12 bends with 8 subsamples per bend, would be required to detect a 5 percent annual decline in most of the target fish populations. Power varied between Zones. Zone 1 (upstream from Lake Sakakawea) did not have any species/gear type combinations with adequate power, whereas Zone 3 (downstream from Gavins Point Dam) had 19 species/gear type combinations with adequate power. With a slight increase in the sampling effort to 12 subsamples per bend, the Pallid Sturgeon Population Assessment Program has adequate power to detect declines in shovelnose sturgeon (S. platorynchus) throughout the entire Missouri River because of large catch rates. The lowest level of non-occurrence (in other words, zero catches) at the bend level for pallid sturgeon was 0.58 using otter trawls in Zone 1. Consequently, the power of the pallid sturgeon models was not as high as other species at the current level of sampling, but an increase in the sampling effort to 16 subsamples for each of 24 bends for 20 years would generate adequate power for the pallid sturgeon in all Zones. Since gear types are selective in their species efficiency, the strength of the Pallid Sturgeon Population Assessment Program approach is using multiple gears that have statistical power to detect population trends at the same time in different fish species within the Missouri River. As often is the case with monitoring studies involving endangered species, the data used to conduct the analyses exhibit some departures from the parametric model assumptions; however, preliminary simulations indicate that the results of this study are appropriate.
Hartman, Linda; Rasch, Linda A; Klausch, Thomas; Bijlsma, Hans W J; Christensen, Robin; Smulders, Yvo M; Ralston, Stuart H; Buttgereit, Frank; Cutolo, Maurizio; Da Silva, Jose A P; Opris, Daniela; Rovenský, Jozef; Szamosi, Szilvia; Middelink, Leonie M; Lems, Willem F; Boers, Maarten
2018-01-25
Rheumatoid arthritis (RA) is a chronic inflammatory disease of the joints affecting 1% of the world population. It has major impact on patients through disability and associated comorbidities. Current treatment strategies have considerably improved the prognosis, but recent innovations (especially biologic drugs and the new class of so-called "JAK/STAT inhibitors") have important safety issues and are very costly. Glucocorticoids (GCs) are highly effective in RA, and could reduce the need for expensive treatment with biologic agents. However, despite more than 65 years of clinical experience, there is a lack of studies large enough to adequately document the benefit/harm balance. The result is inappropriate treatment strategies, i.e. both under-use and over-use of GCs, and consequently suboptimal treatment of RA. The GLORIA study is a pragmatic multicentre, 2-year, randomised, double-blind, clinical trial to assess the safety and effectiveness of a daily dose of 5 mg prednisolone or matching placebo added to standard of care in elderly patients with RA. Eligible participants are diagnosed with RA, have inadequate disease control (disease activity score, DAS28 ≥ 2.6), and are ≥ 65 years. The primary outcome measures are the time-averaged mean value of the DAS28 and the occurrence of serious adverse events or adverse events of special interest. During the trial, change in antirheumatic therapy is permitted as clinically indicated, except for GCs. Cost-effectiveness and cost-utility are secondary outcomes. The main challenge is the interpretation of the trial result with two primary endpoints and the pragmatic trial design that allows co-interventions. Another challenge is the definition of safety and the relative lack of power to detect differences between treatment groups. We have chosen to define safety as the number of patients experiencing at least one serious adverse event. We also specify a decision tree to guide our conclusion on the balance of benefit and harm, and our methodology to combat potential confounding caused by co-interventions. Pragmatic trials minimise impact on daily practice and maximise clinical relevance of the results, but analysis and interpretation of the results is challenging. We expect that the results of this trial are of importance for all rheumatologists who treat elderly patients with RA. ClinicalTrials.gov, NCT02585258 . Registered on 20 October 2015.
Holgado, Darías; Zandonai, Thomas; Zabala, Mikel; Hopker, James; Perakakis, Pandelis; Luque-Casado, Antonio; Ciria, Luis; Guerra-Hernandez, Eduardo; Sanabria, Daniel
2018-07-01
To investigate the effect of tramadol on performance during a 20-min cycling time-trial (Experiment 1), and to test whether sustained attention would be impaired during cycling after tramadol intake (Experiment 2). Randomized, double-blind, placebo controlled trial. In Experiment 1, participants completed a cycling time-trial, 120-min after they ingested either tramadol or placebo. In Experiment 2, participants performed a visual oddball task during the time-trial. Electroencephalography measures (EEG) were recorded throughout the session. In Experiment 1, average time-trial power output was higher in the tramadol vs. placebo condition (tramadol: 220W vs. placebo: 209W; p<0.01). In Experiment 2, no differences between conditions were observed in the average power output (tramadol: 234W vs. placebo: 230W; p>0.05). No behavioural differences were found between conditions in the oddball task. Crucially, the time frequency analysis in Experiment 2 revealed an overall lower target-locked power in the beta-band (p<0.01), and higher alpha suppression (p<0.01) in the tramadol vs. placebo condition. At baseline, EEG power spectrum was higher under tramadol than under placebo in Experiment 1 while the reverse was true for Experiment 2. Tramadol improved cycling power output in Experiment 1, but not in Experiment 2, which may be due to the simultaneous performance of a cognitive task. Interestingly enough, the EEG data in Experiment 2 pointed to an impact of tramadol on stimulus processing related to sustained attention. EudraCT number: 2015-005056-96. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.
School-Based Methylphenidate Placebo Protocols: Methodological and Practical Issues.
ERIC Educational Resources Information Center
Hyman, Irwin A.; Wojtowicz, Alexandra; Lee, Kee Duk; Haffner, Mary Elizabeth; Fiorello, Catherine A.; And Others
1998-01-01
Focuses on methodological issues involved in choosing instruments to monitor behavior, once a comprehensive evaluation has suggested trials on Ritalin. Case examples illustrate problems of teacher compliance in filling out measures, supplying adequate placebos, and obtaining physical cooperation. Emerging school-based methodologies are discussed…
Continuous subcutaneous infusion of opiates at end-of-life.
Anderson, Stacey L; Shreve, Scott T
2004-06-01
To review pertinent controlled trials using the continuous subcutaneous infusion of opioids (CSIO) at end-of-life and offer insight to pharmacists and clinicians into the appropriate use of this route of administration. A MEDLINE search for information regarding the subcutaneous administration of opioids in terminally ill patients (1975-December 2002) was conducted using the key words subcutaneous, narcotics, morphine, hydromorphone, fentanyl, pain, hospices, and palliative care. Additional references were located through review of bibliographies of the articles cited. Case reports and postsurgical studies were excluded. Searches were limited to English-language studies using humans. Experimental and observational studies were evaluated, using prospective trials as the evidence base for conclusions and including pertinent retrospective trials as they relate to the subcutaneous infusion of opioids at end-of-life. CSIO is effective and safe for use in terminal illness. Appropriate situations for consideration of CSIO are when difficulties arise in using the oral route, standard oral opiate therapy has failed adequate trials, the patient has limited intravenous access, adequate supervision of the CSIO is present, and CSIO will not unduly limit the functional activity of the patient. CSIO has a proven role in the management of pain at end-of-life. CSIO should not be considered the first route for administration of opiates, but does offer distinct advantages in the appropriate setting. CSIO continues to be a choice for end-of-life patients and is gradually becoming a standard practice in palliative medicine.
Daikhin, Luba; Raviv, Ofri; Ahissar, Merav
2017-02-01
The reading deficit for people with dyslexia is typically associated with linguistic, memory, and perceptual-discrimination difficulties, whose relation to reading impairment is disputed. We proposed that automatic detection and usage of serial sound regularities for individuals with dyslexia is impaired (anchoring deficit hypothesis), leading to the formation of less reliable sound predictions. Agus, Carrión-Castillo, Pressnitzer, and Ramus, (2014) reported seemingly contradictory evidence by showing similar performance by participants with and without dyslexia in a demanding auditory task that contained task-relevant regularities. To carefully assess the sensitivity of participants with dyslexia to regularities of this task, we replicated their study. Thirty participants with and 24 without dyslexia performed the replicated task. On each trial, a 1-s noise stimulus was presented. Participants had to decide whether the stimulus contained repetitions (was constructed from a 0.5-s noise segment repeated twice) or not. It is implicit in this structure that some of the stimuli with repetitions were themselves repeated across trials. We measured the ability to detect within-noise repetitions and the sensitivity to cross-trial repetitions of the same noise stimuli. We replicated the finding of similar mean performance. However, individuals with dyslexia were less sensitive to the cross-trial repetition of noise stimuli and tended to be more sensitive to repetitions in novel noise stimuli. These findings indicate that online auditory processing for individuals with dyslexia is adequate but their implicit retention and usage of sound regularities is indeed impaired.
Health literacy and usability of clinical trial search engines.
Utami, Dina; Bickmore, Timothy W; Barry, Barbara; Paasche-Orlow, Michael K
2014-01-01
Several web-based search engines have been developed to assist individuals to find clinical trials for which they may be interested in volunteering. However, these search engines may be difficult for individuals with low health and computer literacy to navigate. The authors present findings from a usability evaluation of clinical trial search tools with 41 participants across the health and computer literacy spectrum. The study consisted of 3 parts: (a) a usability study of an existing web-based clinical trial search tool; (b) a usability study of a keyword-based clinical trial search tool; and (c) an exploratory study investigating users' information needs when deciding among 2 or more candidate clinical trials. From the first 2 studies, the authors found that users with low health literacy have difficulty forming queries using keywords and have significantly more difficulty using a standard web-based clinical trial search tool compared with users with adequate health literacy. From the third study, the authors identified the search factors most important to individuals searching for clinical trials and how these varied by health literacy level.
Hyttel-Sorensen, Simon; Greisen, Gorm; Als-Nielsen, Bodil; Gluud, Christian
2017-09-04
Cerebral injury and long-term neurodevelopmental impairment is common in extremely preterm infants. Cerebral near-infrared spectroscopy (NIRS) enables continuous estimation of cerebral oxygenation. This diagnostic method coupled with appropriate interventions if NIRS is out of normal range (that is cerebral oxygenation within the 55% to 85% range) may offer benefits without causing more harms. Therefore, NIRS coupled with appropriate responses to abnormal findings on NIRS needs assessment in a systematic review of randomised clinical trials and quasi-randomised studies. To evaluate the benefits and harms of interventions that attempt to alter cerebral oxygenation guided by cerebral NIRS monitoring in order to prevent cerebral injury, improve neurological outcome, and increase survival in preterm infants born more than 8 weeks preterm. We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 8), MEDLINE via PubMed (1966 to 10 September 2016), Embase (1980 to 10 September 2016), and CINAHL (1982 to 10 September 2016). We also searched clinical trial databases, conference proceedings, and the reference lists of retrieved articles for randomised clinical trials and quasi-randomised studies. Randomised clinical trials and quasi-randomised clinical studies comparing continuous cerebral NIRS monitoring for at least 24 hours versus blinded NIRS or versus no NIRS monitoring. Two review authors independently selected, assessed the quality of, and extracted data from the included trials and studies. If necessary, we contacted authors for further information. We conducted assessments of risks of bias; risks of design errors; and controlled the risks of random errors with Trial Sequential Analysis. We assessed the quality of the evidence with GRADE. One randomised clinical trial met inclusion criteria, including infants born more than 12 weeks preterm. The trial employed adequate methodologies and was assessed at low risk of bias. One hundred and sixty-six infants were randomised to start continuous cerebral NIRS monitoring less than 3 hours after birth until 72 hours after birth plus appropriate interventions if NIRS was out of normal range according to a guideline versus conventional monitoring with blinded NIRS. There was no effect of NIRS plus guideline of mortality until term-equivalent age (RR 0.50, 95% CI 0.29 to 1.00; one trial; 166 participants). There were no effects of NIRS plus guideline on intraventricular haemorrhages: all grades (RR 0.93, 95% CI 0.65 to 1.34; one trial; 166 participants); grade III/IV (RR 0.57, 95% CI 0.25 to 1.31; one trial; 166 participants); and cystic periventricular leukomalacia (which did not occur in either group). Likewise, there was no effect of NIRS plus guideline on the occurrence of a patent ductus arteriosus (RR 1.96, 95% CI 0.94 to 4.08; one trial; 166 participants); chronic lung disease (RR 1.27, 95% CI 0.94 to 1.50; one trial; 166 participants); necrotising enterocolitis (RR 0.83, 95% CI 0.33 to 1.94; one trial; 166 participants); and retinopathy of prematurity (RR 1.64, 95% CI 0.75 to 3.00; one trial; 166 participants). There were no serious adverse events in any of the intervention groups. NIRS plus guideline caused more skin marks from the NIRS sensor in the control group than in the experimental group (unadjusted RR 0.31, 95% CI 0.10 to 0.92; one trial; 166 participants). There are no data regarding neurodevelopmental outcome, renal impairment or air leaks.The quality of evidence for all comparisons discussed above was assessed as very low apart from all-cause mortality and adverse events: these were assessed as low and moderate, respectively. The validity of all comparisons is hampered by a small sample of randomised infants, risk of bias due to lack of blinding, and indirectness of outcomes. The only eligible randomised clinical trial did not demonstrate any consistent effects of NIRS plus a guideline on the assessed clinical outcomes. The trial was, however, only powered to detect difference in cerebral oxygenation, not morbidities or mortality. Our systematic review did not reach sufficient power to prove or disprove effects on clinical outcomes. Further randomised clinical trials with low risks of bias and low risks of random errors are needed.
Psychological therapies for sickle cell disease and pain.
Anie, K A; Green, J
2002-01-01
Sickle cell disease comprises a group of genetic blood disorders, and occurs when the sickle haemoglobin gene is inherited from both parents. The effects of the condition are: varying degrees of anaemia which if severe reduce the capacity for mobility; predisposition to obstruction of small blood capillaries causing pain in muscle and bone known as "crises"; damage to major organs such as the spleen, liver, kidneys, and lungs; and increased vulnerability to severe infections. There are both medical and non-medical complications, and treatment is usually symptomatic and palliative in nature. Psychological intervention for individuals with sickle cell disease seems viable in complementing current medical treatment, and studies examining their efficacy appear to have also yielded encouraging results. To examine the evidence that in patients with sickle cell disease, psychological treatment improves the ability to cope with the condition. The Cochrane Cystic Fibrosis and Genetic Disorders Group specialist trials register which comprises references from comprehensive electronic database searches. Also, hand searching relevant journals, hand searching abstract books of conference proceedings, and searches on the Internet were performed. Date of the most recent search of the Group's specialised register: January 2001. All randomised or quasi-randomised controlled trials comparing the use of psychological intervention to no (psychological) intervention in patients with sickle cell disease. Both reviewers independently extracted data and assessed trial quality. Five studies were identified in the initial search, of which three studies, with a total of 158 patients were eligible for inclusion in the review. Published data reveal that family education and cognitive behavioural therapy can help patients cope with sickle cell disease. Patient education programmes improve knowledge and attitudes of patients with sickle cell disease. There is as yet however, insufficient evidence to demonstrate the role of other psychological therapies. This systematic review has clearly identified the need for well-designed, adequately powered, multicentre randomised controlled trials assessing the effectiveness of specific intervention in sickle cell disease.
Simons, Monique; Chinapaw, Mai J M; van de Bovenkamp, Maaike; de Boer, Michiel R; Seidell, Jacob C; Brug, Johannes; de Vet, Emely
2014-03-24
Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games--i.e. active games--may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12-16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents' measured BMI-SDS (SDS=adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents' self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents. Dutch Trial register NTR3228.
Non-nutritive sucking for gastro-oesophageal reflux disease in preterm and low birth weight infants.
Psaila, Kim; Foster, Jann P; Richards, Robyn; Jeffery, Heather E
2014-10-15
Gastro-oesophageal reflux (GOR) is commonly diagnosed in the neonatal population (DiPietro 1994), and generally causes few or no symptoms (Vandenplas 2009). Conversely, gastro-oesophageal reflux disease (GORD) refers to GOR that causes troublesome symptoms with or without complications such as damage to the oesophagus (Vandenplas 2009). Currently there is no evidence to support the range of measures recommended to help alleviate acid reflux experienced by infants. Non-nutritive sucking (NNS) has been used as an intervention to modulate neonatal state behaviours through its pacifying effects such as decrease infant fussiness and crying during feeds (Boiron 2007; Pickler 2004). To determine if NNS reduces GORD in preterm infants (less than 37 weeks' gestation) and low birth weight (less than 2500 g) infants, three months of age and less, with signs or symptoms suggestive of GORD, or infants with a diagnosis of GORD. We performed computerised searches of the electronic databases of the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 9, 2013), MEDLINE (1966 to September 2013), CINAHL (1982 to September 2013), and EMBASE (1988 to September 2013). We applied no language restrictions. Controlled trials using random or quasi-random allocation of preterm infants (less than 37 weeks' gestation) and low birth weight (less than 2500 g) infants three months of age and less with signs or symptoms suggestive of GORD, or infants with a diagnosis of GORD. We included studies reported only by abstracts, and cluster and cross-over randomised trials. Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data. We identified two studies from the initial search. After further review, we excluded both studies. We identified no studies examining the effects of NNS for GORD in preterm and low birth weight infants There was insufficient evidence to determine the effectiveness of NNS for GORD. Adequately powered RCTs on the effect of NNS in preterm and low birth weight infants diagnosed with GORD are required.
Hald, Jannie D; Evangelou, Evangelos; Langdahl, Bente L; Ralston, Stuart H
2015-05-01
Bisphosphonates are widely used off-label in the treatment of patients with osteogenesis imperfecta (OI) with the intention of reducing the risk of fracture. Although there is strong evidence that bisphosphonates increase bone mineral density in osteogenesis imperfecta, the effects on fracture occurrence have been inconsistent. The aim of this study was to gain a better insight into the effects of bisphosphonate therapy on fracture risk in patients with osteogenesis imperfecta by conducting a meta-analysis of randomized controlled trials in which fractures were a reported endpoint. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials in which the effects of bisphosphonates on fracture risk in osteogenesis imperfecta were compared with placebo and conducted a meta-analysis of these studies using standard methods. Heterogeneity was assessed using the I2 statistic. Six eligible studies were identified involving 424 subjects with 751 patient-years of follow-up. The proportion of patients who experienced a fracture was not significantly reduced by bisphosphonate therapy (Relative Risk [RR] = 0.83 [95% confidence interval 0.69-1.01], p = 0.06) with no heterogeneity between studies (I2 = 0). The fracture rate was reduced by bisphosphonate treatment when all studies were considered (RR = 0.71 [0.52-0.96], p = 0.02), but with considerable heterogeneity (I2 = 36%) explained by one study where a small number of patients in the placebo group experienced a large number of fractures. When this study was excluded, the effects of bisphosphonates on fracture rate was not significant (RR = 0.79 [0.61-1.02], p = 0.07, I2 = 0%). We conclude that the effects of bisphosphonates on fracture prevention in osteogenesis imperfecta are inconclusive. Adequately powered trials with a fracture endpoint are needed to further investigate the risks and benefits of bisphosphonates in this condition. © 2014 American Society for Bone and Mineral Research.
Bonsu, Kwadwo Osei; Reidpath, Daniel Diamond; Kadirvelu, Amudha
2015-12-01
Statins are known to prevent heart failure (HF). However, it is unclear whether statins as class or type (lipophilic or hydrophilic) improve outcomes of established HF. The current meta-analysis was performed to compare the treatment effects of lipophilic and hydrophilic statins on inflammation and cardiac function in HF. Outcomes were indicators of cardiac function [changes in left ventricular ejection fraction (LVEF) and B-type natriuretic peptide (BNP)] and inflammation [changes in highly sensitive C-reactive protein (hsCRP) and interluekin-6 (IL-6)]. We conducted a search of PubMed, EMBASE, and the Cochrane databases until December 31, 2014 for randomized control trials (RCTs) of statin versus placebo in patients with HF. RCTs with their respective extracted information were dichotomized into statin type evaluated and analyzed separately. Outcomes were pooled with random effect approach, producing standardized mean differences (SMD) for each statin type. Using these pooled estimates, we performed adjusted indirect comparisons for each outcome. Data from 6214 patients from 19 trials were analyzed. Lipophilic statin was superior to hydrophilic statin treatment regarding follow-up LVEF (SMD, 4.54; 95% CI, 4.16-4.91; P < 0.001), BNP (SMD, -1.60; 95% CI, -2.56 to -0.65; P < 0.001), hsCRP (SMD, -1.13; 95% CI, -1.54 to -0.72; P < 0.001), and IL-6 (SMD, -3.75; 95% CI, -4.77 to -0.72; P < 0.001) in HF. Lipophilic statin produces greater treatment effects on cardiac function and inflammation compared with hydrophilic statin in patients with HF. Until data from adequately powered head-to-head trial of the statin types are available, our meta-analysis brings clinicians and researchers a step closer to the quest on which statin--lipophilic or hydrophilic--is associated with better outcomes in HF. © 2015 John Wiley & Sons Ltd.
Manual perineal support at the time of childbirth: a systematic review and meta-analysis.
Bulchandani, S; Watts, E; Sucharitha, A; Yates, D; Ismail, K M
2015-08-01
Genital tract trauma is common with vaginal births and is associated with significant morbidity, particularly with obstetric anal sphincter injuries (OASIS). Debate continues regarding the effectiveness of perineal support during childbirth in reducing the risk of trauma. This review aimed to assess the effect of routine 'hands on'/manual perineal support (MPS) during childbirth, versus ad hoc/no perineal support ('hands off/poised'), on the risk and degree of perineal trauma. This review is registered on PROSPERO (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007058). We searched the CENTRAL, Embase, Medline, CINAHL, and OVIDs midwifery and infant care databases (from inception to December 2014). Published randomised controlled trials (RCTs) and non-randomised studies (NRSs) evaluating any 'hands on' perineal support technique during childbirth. Two reviewers independently assessed trials for inclusion, data extraction, and methodological quality. Discrepancies were resolved by discussion with a third reviewer. We included five RCTs and seven NRSs in the review. Meta-analysis of RCTs did not demonstrate a statistically significant protective effect of MPS on the risk of OASIS (three studies, 6647 women; relative risk, RR 1.03; 95% confidence interval, 95% CI 0.32-3.36; statistical test for heterogeneity I(2) = 71%). Meta-analysis of NRSs showed a significant reduction in the risk of OASIS with MPS (three studies, 74,744 women; RR 0.45; 95% CI 0.40-0.50; I(2) = 32%). Current evidence is insufficient to drive change in practice. An adequately powered randomised trial with an efficient design to evaluate the complex interventions adopted as part of MPS policies, ensuring controlled childbirth, is urgently needed. © 2015 Royal College of Obstetricians and Gynaecologists.
Recruitment methods employed in the prostate, lung, colorectal, and ovarian cancer screening trial
Gren, Lisa; Broski, Karen; Childs, Jeffery; Cordes, Jill; Engelhard, Deborah; Gahagan, Betsy; Gamito, Eduard; Gardner, Vivien; Geisser, Mindy; Higgins, Darlene; Jenkins, Victoria; Lamerato, Lois; Lappe, Karen; Lowery, Heidi; McGuire, Colleen; Miedzinski, Mollie; Ogden, Sheryl; Tenorio, Sally; Watt, Gavin; Wohlers, Bonita; Marcus, Pamela
2015-01-01
Background The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) is a US National Cancer Institute (NCI)-funded randomized controlled trial designed to evaluate whether certain screening tests reduce mortality from prostate, lung, colorectal, and ovarian cancer. To obtain adequate statistical power, it was necessary to enroll over 150,000 healthy volunteers. Recruitment began in 1993 and ended in 2001. Purpose Our goal is to evaluate the success of recruitment methods employed by the 10 PLCO screening centers. We also provide estimates of recruitment yield and cost for our most successful strategy, direct mail. Methods Each screening center selected its own methods of recruitment. Methods changed throughout the recruitment period as needed. For this manuscript, representatives from each screening center provided information on methods utilized and their success. Results In the United States between 1993 and 2001, ten screening centers enrolled 154,934 study participants. Based on participant self-report, an estimated 95% of individuals were recruited by direct mail. Overall, enrollment yield for direct mail was 1.0%. Individual center enrollment yield ranged from 0.7% to 3.8%. Cost per enrolled participant was $9.64–35.38 for direct mail, excluding personnel costs. Limitations Numeric data on recruitment processes were not kept consistently at individual screening centers. Numeric data in this manuscript are based on the experiences of 5 of the 10 centers. Conclusions Direct mail, using rosters of names and addresses from profit and not-for-profit (including government) organizations, was the most successful and most often used recruitment method. Other recruitment strategies, such as community outreach and use of mass media, can be an important adjunct to direct mail in recruiting minority populations. PMID:19254935
Santos-Jasso, Karla Alejandra; Arredondo-García, José Luis; Maza-Vallejos, Jorge; Lezama-Del Valle, Pablo
2017-01-01
Constipation is present in 80% of children with corrected anorectal malformations, usually associated to rectal dilation and hypomotility. Osmotic laxatives are routinely used for idiopathic constipation. Senna is a stimulant laxative that produces contractions improving colonic motility without affecting the stool consistency. We designed this trial to study the effectiveness of Senna versus polyethylene glycol for the treatment of constipation in children with anorectal malformation. A randomized controlled crossover design clinical trial, including a washout period, was conducted, including children with corrected anorectal malformations with fecal continence and constipation. The sample size was calculated for proportions (n=28) according to available data for Senna. Effectiveness of laxative therapy was measured with a three variable construct: 1) daily bowel movement, 2) fecal soiling, 3) a "clean" abdominal x-ray. Data analysis included descriptive statistics and a Fisher's exact test for the outcome variable (effectiveness). The study was terminated early because the interim analysis showed a clear benefit toward Senna (p = 0.026). The sample showed a normal statistical distribution for the variables age and presence of megarectum. The maximum daily dose of Senna (sennosides A and B) was 38.7mg and 17g for polyethylene glycol. No adverse effects were identified. Therapy with Senna should be the laxative treatment of choice as part of a bowel management program in children with repaired anorectal malformations and constipation, since the stimulation of colonic propulsion waves could lead to stool evacuation without modification of its consistency which can affect fecal continence. I - randomized controlled trial with adequate statistical power. Copyright © 2017 Elsevier Inc. All rights reserved.
Von Korff, Michael; Vitiello, Michael V; McCurry, Susan M; Balderson, Benjamin H; Moore, Amy L; Baker, Laura D; Yarbro, Patricia; Saunders, Kathleen; Keefe, Francis J; Rybarczyk, Bruce D
2012-07-01
Six weekly sessions of group cognitive-behavioral therapy for insomnia and osteoarthritis pain (CBT-PI), and for osteoarthritis pain alone (CBT-P) were compared to an education only control (EOC). Basic education about pain and sleep was comparable, so EOC controlled for information and group participation. Active interventions differed from EOC in training pain coping skills (CBT-P and CBT-PI) and sleep enhancement techniques (CBT-PI). Persons with osteoarthritis age 60 or older were screened for osteoarthritis pain and insomnia severity via mailed survey. Primary outcomes were pain severity (pain intensity and interference ratings from the Graded Chronic Pain Scale) and insomnia severity (Insomnia Severity Index). Secondary outcomes were arthritis pain (AIMS-2 symptom scale) and sleep efficiency assessed by wrist actigraphy. Ancillary outcomes included: cognitive function, depression, and health care use. A clustered randomized design provided adequate power to identify moderate effects on primary outcomes (effect size>0.35). Modified intent to treat analyses, including all participants who attended the first session, assessed effects across CBT-PI, CBT-P, and EOC groups. Treatment effects were assessed post-intervention (2 months) and at 9 months, with durability of intervention effects evaluated at 18 months. The trial was executed in 6 primary clinics, randomizing 367 participants, with 93.2% of randomized patients attending at least 4 group sessions. Response rates for post-intervention and 9 month assessments were 96.7% and 92.9% respectively. This hybrid efficacy-effectiveness trial design evaluates whether interventions yield specific benefits for clinical and behavioral outcomes relative to an education only control when implemented in a primary care setting. Copyright © 2012 Elsevier Inc. All rights reserved.
Antolovic, D; Rakow, A; Contin, P; Ulrich, A; Rahbari, N N; Büchler, M W; Weitz, J; Koch, M
2012-02-01
Surgeons are increasingly confronted by patients on long-term low-dose acetylsalicylic acid (ASA). However, owing to a lack of evidence-based data, a widely accepted consensus on the perioperative management of these patients in the setting of non-cardiac surgery has not yet been reached. Primary objective was to evaluate the safety of continuous versus discontinuous use of ASA in the perioperative period in elective general or abdominal surgery. Fifty-two patients undergoing elective cholecystectomy, inguinal hernia repair or colonic/colorectal surgery were recruited to this pilot study. According to cardiological evaluation, non-high-risk patients who were on long-term treatment with low-dose ASA were eligible for inclusion. Patients were allocated randomly to continuous use of ASA or discontinuation of ASA intake for 5 days before until 5 days after surgery. The primary outcome was the incidence of major haemorrhagic and thromboembolic complications within 30 days after surgery. A total of 26 patients were allocated to each study group. One patient (3.8%) in the ASA continuation group required re-operation due to post-operative haemorrhage. In neither study group, further bleeding complications occurred. No clinically apparent thromboembolic events were reported in the ASA continuation and the ASA discontinuation group. Furthermore, there were no significant differences between both study groups in the secondary endpoints. Perioperative intake of ASA does not seem to influence the incidence of severe bleeding in non-high-risk patients undergoing elective general or abdominal surgery. Further, adequately powered trials are required to confirm the findings of this study.
Safety of intravenous alteplase within 4.5 hours for patients awakening with stroke symptoms.
Urrutia, Victor C; Faigle, Roland; Zeiler, Steven R; Marsh, Elisabeth B; Bahouth, Mona; Cerdan Trevino, Mario; Dearborn, Jennifer; Leigh, Richard; Rice, Susan; Lane, Karen; Saheed, Mustapha; Hill, Peter; Llinas, Rafael H
2018-01-01
Up to 25% of acute stroke patients first note symptoms upon awakening. We hypothesized that patients awaking with stroke symptoms may be safely treated with intravenous alteplase (IV tPA) using non-contrast head CT (NCHCT), if they meet all other standard criteria. The SAfety of Intravenous thromboLytics in stroke ON awakening (SAIL ON) was a prospective, open-label, single treatment arm, pilot safety trial of standard dose IV tPA in patients who presented with stroke symptoms within 0-4.5 hours of awakening. From January 30, 2013, to September 1, 2015, twenty consecutive wakeup stroke patients selected by NCHCT were enrolled. The primary outcome was symptomatic intracerebral hemorrhage (sICH) in the first 36 hours. Secondary outcomes included NIH stroke scale (NIHSS) at 24 hours; and modified Rankin Score (mRS), NIHSS, and Barthel index at 90 days. The average age was 65 years (range 47-83); 40% were women; 50% were African American. The average NIHSS was 6 (range 4-11). The average time from wake-up to IV tPA was 205 minutes (range 114-270). The average time from last known well to IV tPA was 580 minutes (range 353-876). The median mRS at 90 days was 1 (range 0-5). No patients had sICH; two of 20 (10%) had asymptomatic ICH on routine post IV tPA brain imaging. Administration of IV tPA was feasible and may be safe in wakeup stroke patients presenting within 4.5 hours from awakening, screened with NCHCT. An adequately powered randomized clinical trial is needed. ClinicalTrials.gov NCT01643902.
Leichman, Cynthia Gail; McDonough, Shannon L; Smalley, Stephen R; Billingsley, Kevin G; Lenz, Heinz-Josef; Beldner, Matthew A; Hezel, Aram F; Velasco, Mario R; Guthrie, Katherine A; Blanke, Charles D; Hochster, Howard S
2018-03-01
Neoadjuvant chemoradiation (NCRT) is standard treatment for locally advanced rectal cancer. Pathologic complete response (pCR) has associated with improved survival. In modern phase III trials of NCRT, pCR ranges from 10% to 20%. Cetuximab improves response in KRAS (KRAS proto-oncogene) wild type (wt) metastatic colorectal cancer. S0713 was designed to assess improvement in pCR with additional use of cetuximab with induction chemotherapy and NCRT for locally advanced, KRAS-wt rectal cancer. Patient eligibility: stage II to III biopsy-proven, KRAS-wt rectal adenocarcinoma; no bowel obstruction; adequate hematologic, hepatic and renal function; performance status of 0 to 2. Target enrollment: 80 patients. induction chemotherapy with wCAPOX (weekly capecitabine and oxaliplatin) and cetuximab followed by the same regimen concurrent with radiation (omitting day 15 oxaliplatin). If fewer than 7 pCRs were observed at planned interim analysis after 40 patients received all therapy, the study would close. Eighty eligible patients would provide 90% power given a true pCR rate > 35% at a significance of 0.04. The regimen would lack future interest if pCR probability was ≤ 20%. Between February 2009 and April 2013, 83 patients registered. Four were ineligible and 4 not treated, leaving 75 evaluable for clinical outcomes and toxicity, of whom 65 had surgery. Of 75 patients, 20 had pCR (27%; 95% confidence interval [CI], 17%-38%); 19 (25%) had microscopic cancer; 36 (48%) had minor/no response (including 10 without surgery). Three-year disease-free survival was 73% (95% CI, 63%-83%). Our trial did not meet the pCR target of 35%. Toxicity was generally acceptable. This regimen cannot be recommended outside the clinical trial setting. Copyright © 2017 Elsevier Inc. All rights reserved.
Miyauchi, Katsumi; Kimura, Takeshi; Shimokawa, Hiroaki; Daida, Hiroyuki; Iimuro, Satoshi; Iwata, Hiroshi; Ozaki, Yukio; Sakuma, Ichiro; Nakagawa, Yoshihisa; Hibi, Kiyoshi; Hiro, Takafumi; Fukumoto, Yoshihiro; Hokimoto, Seiji; Ohashi, Yasuo; Ohtsu, Hiroshi; Saito, Yasushi; Matsuzaki, Masunori; Nagai, Ryozo
2018-03-30
Large-scale clinical trials in patients in Western countries with coronary artery disease (CAD) have found that aggressive lipid-lowering therapy using high-dose statins reduces cardiovascular (CV) events further than low-dose statins. However, such evidence has not yet been fully established in Asian populations, including in Japan. The Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study addresses whether intensification of statin therapy improves clinical outcomes in Japanese patients with CAD.REAL-CAD is a prospective, multicenter, randomized, open-label, blinded-endpoint, physician-initiated phase 4 trial in Japan. The study will recruit up to 12,600 patients with stable CAD. Patients are assigned to receive either pitavastatin 1 mg/day or pitavastatin 4 mg/day. LDL-C levels are expected to reach approximate mean values of 100 mg/dL in the low-dose pitavastatin group and 80 mg/dL in the high-dose group. The primary endpoint is the time to occurrence of a major CV event, including CV death, non-fatal myocardial infarction, non-fatal ischemic stroke, and unstable angina requiring emergency hospitalization during an average of 5 years. The large number of patients and the long follow-up period in the REAL-CAD study should ensure that there is adequate power to definitively determine if reducing LDL-C levels to approximately 80 mg/dL by high-dose statin can provide additional clinical benefit.After the study is completed, we will have categorical evidence on the optimal statin dose and target LDL-C level for secondary prevention in Japanese patients.
A Randomized Controlled Trial of Compression Rates during Cardiopulmonary Resuscitation
2016-01-01
The objective of this study was to compare the efficacy of cardiopulmonary resuscitation (CPR) with 120 compressions per minute (CPM) to CPR with 100 CPM in patients with non-traumatic out-of-hospital cardiac arrest. We randomly assigned patients with non-traumatic out-of-hospital cardiac arrest into two groups upon arrival to the emergency department (ED). The patients received manual CPR either with 100 CPM (CPR-100 group) or 120 CPM (CPR-120 group). The primary outcome measure was sustained restoration of spontaneous circulation (ROSC). The secondary outcome measures were survival discharge from the hospital, one-month survival, and one-month survival with good functional status. Of 470 patients with cardiac arrest, 136 patients in the CPR-100 group and 156 patients in the CPR-120 group were included in the final analysis. A total of 69 patients (50.7%) in the CPR-100 group and 67 patients (42.9%) in the CPR-120 group had ROSC (absolute difference, 7.8% points; 95% confidence interval [CI], -3.7 to 19.2%; P = 0.183). The rates of survival discharge from the hospital, one-month survival, and one-month survival with good functional status were not different between the two groups (16.9% vs. 12.8%, P = 0.325; 12.5% vs. 6.4%, P = 0.073; 5.9% vs. 2.6%, P = 0.154, respectively). We did not find differences in the resuscitation outcomes between those who received CPR with 100 CPM and those with 120 CPM. However, a large trial is warranted, with adequate power to confirm a statistically non-significant trend toward superiority of CPR with 100 CPM. (Clinical Trial Registration Information: www.cris.nih.go.kr, cris.nih.go.kr number, KCT0000231) PMID:27510396
Prestimulus alpha power predicts fidelity of sensory encoding in perceptual decision making.
Lou, Bin; Li, Yun; Philiastides, Marios G; Sajda, Paul
2014-02-15
Pre-stimulus α power has been shown to correlate with the behavioral accuracy of perceptual decisions. In most cases, these correlations have been observed by comparing α power for different behavioral outcomes (e.g. correct vs incorrect trials). In this paper we investigate such covariation within the context of behaviorally-latent fluctuations in task-relevant post-stimulus neural activity. Specially we consider variations of pre-stimulus α power with post-stimulus EEG components in a two alternative forced choice visual discrimination task. EEG components, discriminative of stimulus class, are identified using a linear multivariate classifier and only the variability of the components for correct trials (regardless of stimulus class, and for nominally identical stimuli) are correlated with the corresponding pre-stimulus α power. We find a significant relationship between the mean and variance of the pre-stimulus α power and the variation of the trial-to-trial magnitude of an early post-stimulus EEG component. This relationship is not seen for a later EEG component that is also discriminative of stimulus class and which has been previously linked to the quality of evidence driving the decision process. Our results suggest that early perceptual representations, rather than temporally later neural correlates of the perceptual decision, are modulated by pre-stimulus state. © 2013 Elsevier Inc. All rights reserved.
Prestimulus alpha power predicts fidelity of sensory encoding in perceptual decision making
Lou, Bin; Li, Yun; Philiastides, Marios G.; Sajda, Paul
2013-01-01
Pre-stimulus α power has been shown to correlate with the behavioral accuracy of perceptual decisions. In most cases, these correlations have been observed by comparing α power for different behavioral outcomes (e.g. correct vs incorrect trials). In this paper we investigate such covariation within the context of behaviorally-latent fluctuations in task-relevant post-stimulus neural activity. Specially we consider variations of pre-stimulus α power with post-stimulus EEG components in a two alternative forced choice visual discrimination task. EEG components, discriminative of stimulus class, are identified using a linear multivariate classifier and only the variability of the components for correct trials (regardless of stimulus class, and for nominally identical stimuli) are correlated with the corresponding pre-stimulus α power. We find a significant relationship between the mean and variance of the pre-stimulus α power and the variation of the trial-to-trial magnitude of an early post-stimulus EEG component. This relationship is not seen for a later EEG component that is also discriminative of stimulus class and which has been previously linked to the quality of evidence driving the decision process. Our results suggest that early perceptual representations, rather than temporally later neural correlates of the perceptual decision, are modulated by pre-stimulus state. PMID:24185020
Dark energy homogeneity in general relativity: Are we applying it correctly?
NASA Astrophysics Data System (ADS)
Duniya, Didam G. A.
2016-04-01
Thus far, there does not appear to be an agreed (or adequate) definition of homogeneous dark energy (DE). This paper seeks to define a valid, adequate homogeneity condition for DE. Firstly, it is shown that as long as w_x ≠ -1, DE must have perturbations. It is then argued, independent of w_x, that a correct definition of homogeneous DE is one whose density perturbation vanishes in comoving gauge: and hence, in the DE rest frame. Using phenomenological DE, the consequence of this approach is then investigated in the observed galaxy power spectrum—with the power spectrum being normalized on small scales, at the present epoch z=0. It is found that for high magnification bias, relativistic corrections in the galaxy power spectrum are able to distinguish the concordance model from both a homogeneous DE and a clustering DE—on super-horizon scales.
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.
Niederman, Richard
2014-09-01
The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, CINAHL, National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. Reference lists of identified articles were also scanned for relevant papers. Identified manufacturers were contacted for additional information. Only randomised controlled trials comparing manual and powered toothbrushes were considered. Crossover trials were eligible for inclusion if the wash-out period length was more than two weeks. Study assessment and data extraction were carried out independently by at least two reviewers. The primary outcome measures were quantified levels of plaque or gingivitis. Risk of bias assessment was undertaken. Standard Cochrane methodological approaches were taken. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months). Fifty-six trials were included with 51 (4624 patients) providing data for meta-analysis. The majority (46) were at unclear risk of bias, five at high risk of bias and five at low risk. There was moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short and long-term. This corresponds to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and a 21% reduction in the long term. There was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups.There was also moderate quality evidence that powered toothbrushes again provide a statistically significant reduction in gingivitis when compared with manual toothbrushes both in the short and long term. This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness indices respectively. Again there was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups. The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points. Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses. Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.
Opportunities and pitfalls in clinical proof-of-concept: principles and examples.
Chen, Chao
2018-04-01
Clinical proof-of-concept trials crucially inform major resource deployment decisions. This paper discusses several mechanisms for enhancing their rigour and efficiency. The importance of careful consideration when using a surrogate endpoint is illustrated; situational effectiveness of run-in patient enrichment is explored; a versatile tool is introduced to ensure a strong pharmacological underpinning; the benefits of dose-titration are revealed by simulation; and the importance of adequately scheduled observations is shown. The general process of model-based trial design and analysis is described and several examples demonstrate the value in historical data, simulation-guided design, model-based analysis and trial adaptation informed by interim analysis. Copyright © 2018 Elsevier Ltd. All rights reserved.
Roberts, Lesley M; McCahon, Deborah; Holder, Roger; Wilson, Sue; Hobbs, F D Richard
2013-03-07
Irritable Bowel Syndrome (IBS) is a common condition characterised by pain, distension and altered bowel habit. Evidence suggests functional foods containing probiotics improve gastrointestinal transit, however, data are limited by short follow-up periods and evaluation in selected populations. A multi-centre, randomized, double blind, controlled trial to evaluate the effect of a probiotic vs non-probiotic dairy product on symptoms in IBS with a constipation element (IBS-Constipation or IBS-Mixed profile). Set in 13 general practices within central England. Individuals meeting the ROME III criteria for IBS, aged 18-65 completed a pre-study diary. Eligible individuals were randomized to consume dairy 'yoghurt' products which either did or did not contain active probiotics twice daily and to complete a daily diary. Primary outcome was subjective global assessment of symptom relief at week 4. Other outcomes comprised, IBS symptom scores, pain, bloating and flatulence levels, stool frequency, stool consistency, ease of bowel movement and quality of life. 179 were randomized (91 active, 88 placebo). 76 (43 active, 33 placebo) completed the study. No significant between group differences existed at 4 weeks (57% active vs 53% placebo, reported adequate relief (p = 0.71)). By week 8, 46% active vs 68% placebo reported adequate relief (p = 0.03). This was sustained at week 12. Significant improvements were reported for most outcomes in all trial participants but improvement did not differ by group. This trial does not provide evidence for effectiveness of a probiotic in IBS, in variance with a body of published literature and review conclusions. Differential drop out may however cloud interpretation of data. UK TRIAL REGISTRATION: ISRCTN78863629.
Beighton, Carole; Victor, Christina; Normansell, Rebecca; Cook, Derek; Kerry, Sally; Iliffe, Steve; Ussher, Michael; Whincup, Peter; Fox-Rushby, Julia; Woodcock, Alison; Harris, Tess
2015-12-12
Physical activity (PA) is important for physical and mental health in adults and older adults. Interventions incorporating theory-based behaviour change techniques (BCTs) can be useful in helping people to increase their PA levels and can be delivered by practice nurses in primary care. We undertook two primary care based complex walking interventions among adults and older adults. Both interventions were underpinned by BCTs and delivered by practice nurses and we sought their views and experiences of delivering over 1400 complex PA consultations. Semi structured interviews with two practice nurse groups (n = 4 and n = 5) and two individual interviews (total n = 11) were conducted by independent facilitators; audio-recorded, transcribed verbatim and analysed using thematic analysis. Five key themes emerged as enablers and/or barriers to delivering the intervention: preparation and training; initial and ongoing support; adherence to the protocol; the use of materials and equipment; and engagement of participants. The themes were organised into a framework of 'pre-trial' and 'delivery of the intervention'. Two additional 'post-trial' themes were identified; changed practice and the future feasibility of the intervention. Nurses believed that taking part in the trial, especially the BCT training, enhanced the quality and delivery of advice and support they provided within routine consultations, although the lack of time available routinely makes this challenging. Delivering an effective behaviour change intervention in primary care requires adequate training and support for practice nurses both initially and throughout the trial as well as adequate consultation time. Enhanced skills from participating in such trials can lead to long-term changes, including more patient-centred consulting. PACE-Lift ISRCTN 42122561 , PACE-UP ISRCTN 98538934 .
Stoner, Susan A; Arenella, Pamela B; Hendershot, Christian S
2015-01-01
Naltrexone is a front-line treatment for alcohol use disorders, but its efficacy is limited by poor medication adherence. This randomized controlled trial evaluated whether a mobile health intervention could improve naltrexone adherence. Treatment-seeking participants with an alcohol use disorder (N = 76) were randomized to intervention and control conditions. All participants received naltrexone (50 mg/day) with a medication event monitoring system (MEMS) and a prepaid smartphone, and received a daily text message querying medication side effects, alcohol use, and craving. Those in the intervention arm received additional medication reminders and adherence assessment via text message. The primary outcome, proportion of participants with adequate adherence (defined as ≥80% of prescribed doses taken through Week 8), did not differ between groups in intent-to-treat analyses (p = .34). Mean adherence at study midpoint (Week 4) was 83% in the intervention condition and 77% in the control condition (p = .35). Survival analysis found that the intervention group sustained adequate adherence significantly longer (M = 19 days [95% CI = 0.0-44.0]) than those in the control group (M = 3 days [95% CI = 0.0-8.1]) during the first month of treatment (p = .04). Medication adherence did not predict drinking outcomes. These results suggest that in the context of daily monitoring and assessment via cell phone, additional text message reminders do not further improve medication adherence. Although this initial trial does not provide support for the efficacy of text messaging to improve adherence to pharmacotherapy for alcohol use disorders, additional trials with larger samples and alternate designs are warranted. ClinicalTrials.gov: NCT01349985.
40 CFR 63.10897 - What are my monitoring requirements?
Code of Federal Regulations, 2012 CFR
2012-07-01
... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...
40 CFR 63.10897 - What are my monitoring requirements?
Code of Federal Regulations, 2011 CFR
2011-07-01
... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...
40 CFR 63.10897 - What are my monitoring requirements?
Code of Federal Regulations, 2014 CFR
2014-07-01
... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...
40 CFR 63.10897 - What are my monitoring requirements?
Code of Federal Regulations, 2013 CFR
2013-07-01
... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...
40 CFR 63.10897 - What are my monitoring requirements?
Code of Federal Regulations, 2010 CFR
2010-07-01
... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...
Photovoltaic power systems workshop
NASA Technical Reports Server (NTRS)
Killian, H. J.; Given, R. W.
1978-01-01
Discussions are presented on apparent deficiencies in NASA planning and technology development relating to a standard power module (25-35 kW) and to future photovoltaic power systems in general. Topics of discussion consider the following: (1) adequate studies on power systems; (2) whether a standard power system module should be developed from a standard spacecraft; (3) identification of proper approaches to cost reduction; (4) energy storage avoidance; (5) attitude control; (6) thermal effects of heat rejection on solar array configuration stability; (7) assembly of large power systems in space; and (8) factoring terrestrial photovoltaic work into space power systems for possible payoff.
Power and efficiency of insect flight muscle.
Ellington, C P
1985-03-01
The efficiency and mechanical power output of insect flight muscle have been estimated from a study of hovering flight. The maximum power output, calculated from the muscle properties, is adequate for the aerodynamic power requirements. However, the power output is insufficient to oscillate the wing mass as well unless there is good elastic storage of the inertial energy, and this is consistent with reports of elastic components in the flight system. A comparison of the mechanical power output with the metabolic power input to the flight muscles suggests that the muscle efficiency is quite low: less than 10%.
[Ethical principles of clinical trials in minors].
Koch, H J; Raschka, C
2002-12-05
Clinical trials in volunteers and patients are essential to ensure rational treatment of patients. As a rule, drugs are routinely developed for adults, but children are excluded. A major reason for this restriction are ethical justifications, in particular the lack of autonomy on the part of children. The principle of fairness, however, requires that everyone should benefit from progress. Industry, science and society are therefore called upon to find ways of making available safe and adequate treatment for children as quickly as possible, by defining the required conditions for pediatric clinical trials. Important principles are minimal risk, minimal invasivity, rapid decision-making, and careful documentation of trial results. Dynamic ethical principles, such as autonomy and competence in adolescents must be considered on equal footing with existing international GCP guidelines. Aspects of child psychology indicate that the autonomy of adolescents should be respected. Where economic incentives for such trials are absent, for example, in the case of non-pharmacological problems, pediatric trials must be considered a task for society as a whole.
Morant, Anne Vinther; Vestergaard, Henrik Tang
2018-07-01
A minimum of two positive, adequate, and well-controlled clinical trials has historically been the gold standard for providing substantial evidence to support regulatory approval of a new medicine. Nevertheless, the present analysis of European Marketing Authorizations granted between 2012 and 2016 showed that 45% of new active substances were approved based on a single pivotal clinical trial. For therapeutic areas such as oncology and cardiovascular diseases, approvals based on a single pivotal trial are the rule rather than the exception, whereas new medicines within the nervous system area were generally supported by two or more pivotal trials. While overall similar trends have been observed in the US, the recent US Food and Drug Administration approvals of nervous system medicines based on a single pivotal trial suggest that a case-by-case scientific evaluation of the totality of evidence is increasingly applied to facilitate faster access of new medicines to patients suffering from serious diseases. © 2017 American Society for Clinical Pharmacology and Therapeutics.
Simulations for designing and interpreting intervention trials in infectious diseases.
Halloran, M Elizabeth; Auranen, Kari; Baird, Sarah; Basta, Nicole E; Bellan, Steven E; Brookmeyer, Ron; Cooper, Ben S; DeGruttola, Victor; Hughes, James P; Lessler, Justin; Lofgren, Eric T; Longini, Ira M; Onnela, Jukka-Pekka; Özler, Berk; Seage, George R; Smith, Thomas A; Vespignani, Alessandro; Vynnycky, Emilia; Lipsitch, Marc
2017-12-29
Interventions in infectious diseases can have both direct effects on individuals who receive the intervention as well as indirect effects in the population. In addition, intervention combinations can have complex interactions at the population level, which are often difficult to adequately assess with standard study designs and analytical methods. Herein, we urge the adoption of a new paradigm for the design and interpretation of intervention trials in infectious diseases, particularly with regard to emerging infectious diseases, one that more accurately reflects the dynamics of the transmission process. In an increasingly complex world, simulations can explicitly represent transmission dynamics, which are critical for proper trial design and interpretation. Certain ethical aspects of a trial can also be quantified using simulations. Further, after a trial has been conducted, simulations can be used to explore the possible explanations for the observed effects. Much is to be gained through a multidisciplinary approach that builds collaborations among experts in infectious disease dynamics, epidemiology, statistical science, economics, simulation methods, and the conduct of clinical trials.
Hussein, Norita; Weng, Stephen F; Kai, Joe; Kleijnen, Jos; Qureshi, Nadeem
2018-03-14
Globally, about five per cent of children are born with congenital or genetic disorders. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in specific patient populations. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if genetic counselling is only offered in an antenatal setting. This is an update of a previously published review. To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 20 June 2017.Date of latest search of all other sources: 16 November 2017. Any randomised or quasi-randomised controlled trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care. We identified 25 papers, describing 16 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found. No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were included. One ongoing trial has been identified which may potentially eligible for inclusion once completed. As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.
RELIABILITY OF THE ONE REPETITION-MAXIMUM POWER CLEAN TEST IN ADOLESCENT ATHLETES
Faigenbaum, Avery D.; McFarland, James E.; Herman, Robert; Naclerio, Fernando; Ratamess, Nicholas A.; Kang, Jie; Myer, Gregory D.
2013-01-01
Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the one repetition maximum (1 RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 yrs, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had more than 1 year of training experience with weightlifting exercises performed a 1 RM power clean on two nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for one repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC [2,k]), Pearson correlation coefficient (r), repeated measures ANOVA, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% CI = 0.96–0.99). Testing also demonstrated a strong relationship between 1 RM measures on trial 1 and trial 2 (r=0.98, p<0.0001) with no significant difference in power clean performance between trials (70.6 ± 19.8 vs. 69.8 ± 19.8 kg). Bland Altman plots confirmed no systematic shift in 1 RM between trial 1 and trial 2. The typical error to be expected between 1 RM power clean trials is 2.9 kg and a change of at least 8.0 kg is indicated to determine a real change in lifting performance between tests in young lifters. No injuries occurred during the study period and the testing protocol was well-tolerated by all subjects. These findings indicate that 1 RM power clean testing has a high degree of reproducibility in trained male adolescent athletes when standardized testing procedures are followed and qualified instruction is present. PMID:22233786
2011-01-01
Introduction Succinylcholine and rocuronium are widely used to facilitate rapid sequence induction (RSI) intubation in intensive care. Concerns relate to the side effects of succinylcholine and to slower onset and inferior intubation conditions associated with rocuronium. So far, succinylcholine and rocuronium have not been compared in an adequately powered randomized trial in intensive care. Accordingly, the aim of the present study was to compare the incidence of hypoxemia after rocuronium or succinylcholine in critically ill patients requiring an emergent RSI. Methods This was a prospective randomized controlled single-blind trial conducted from 2006 to 2010 at the University Hospital of Basel. Participants were 401 critically ill patients requiring emergent RSI. Patients were randomized to receive 1 mg/kg succinylcholine or 0.6 mg/kg rocuronium for neuromuscular blockade. The primary outcome was the incidence of oxygen desaturations defined as a decrease in oxygen saturation ≥ 5%, assessed by continuous pulse oxymetry, at any time between the start of the induction sequence and two minutes after the completion of the intubation. A severe oxygen desaturation was defined as a decrease in oxygen saturation ≥ 5% leading to a saturation value of ≤ 80%. Results There was no difference between succinylcholine and rocuronium regarding oxygen desaturations (succinylcholine 73/196; rocuronium 66/195; P = 0.67); severe oxygen desaturations (succinylcholine 20/196; rocuronium 20/195; P = 1.0); and extent of oxygen desaturations (succinylcholine -14 ± 12%; rocuronium -16 ± 13%; P = 0.77). The duration of the intubation sequence was shorter after succinycholine than after rocuronium (81 ± 38 sec versus 95 ± 48 sec; P = 0.002). Intubation conditions (succinylcholine 8.3 ± 0.8; rocuronium 8.2 ± 0.9; P = 0.7) and failed first intubation attempts (succinylcholine 32/200; rocuronium 36/201; P = 1.0) did not differ between the groups. Conclusions In critically ill patients undergoing emergent RSI, incidence and severity of oxygen desaturations, the quality of intubation conditions, and incidence of failed intubation attempts did not differ between succinylcholine and rocuronium. Trial Registration ClinicalTrials.gov, number NCT00355368. PMID:21846380
Interventions to reduce weight gain in schizophrenia.
Faulkner, G; Cohn, T; Remington, G
2007-01-24
Weight gain is common for people with schizophrenia and this has serious implications for health and well being. To determine the effects of both pharmacological (excluding medication switching) and non pharmacological strategies for reducing or preventing weight gain in people with schizophrenia. We searched key databases and the Cochrane Schizophrenia Group's trials register (April 2006), reference sections within relevant papers, hand searched key journals, and contacted the first author of each relevant study and other experts to collect further information. We included all clinical randomised controlled trials comparing any pharmacological or non pharmacological intervention for weight gain (diet and exercise counselling) with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses. We reliably selected, quality assessed and extracted data from studies. As weight is a continuous outcome measurement, weighted mean differences (WMD) of the change from baseline were calculated. The primary outcome measure was weight loss. Twenty-three randomised controlled trials met the inclusion criteria for this review. Five trials assessed a cognitive/behavioural intervention and eighteen assessed a pharmacological adjunct. In terms of prevention, two cognitive/behavioural trials showed significant treatment effect (mean weight change) at end of treatment (n=104, 2 RCTs, WMD -3.38 kg CI -4.2 to -2.0). Pharmacological adjunct treatments were significant with a modest prevention of weight gain (n=274, 6 RCTs, WMD - 1.16 kg CI -1.9 to -0.4). In terms of treatments for weight loss, we found significantly greater weight reduction in the cognitive behavioural intervention group (n=129, 3 RCTs, WMD -1.69 kg CI -2.8 to -0.6) compared with standard care. Modest weight loss can be achieved with selective pharmacological and non pharmacological interventions. However, interpretation is limited by the small number of studies, small sample size, short study duration and by variability of the interventions themselves, their intensity and duration. Future studies adequately powered, with longer treatment duration and rigorous methodology will be needed in further evaluating the efficacy and safety of weight loss interventions for moderating weight gain. At this stage, there is insufficient evidence to support the general use of pharmacological interventions for weight management in people with schizophrenia.
Dumoulin, Chantale; Morin, Mélanie; Mayrand, Marie-Hélène; Tousignant, Michel; Abrahamowicz, Michal
2017-11-16
Urinary incontinence (UI), one of the most prevalent health concerns confronting women aged over 60 years, affects up to 55% of older community-dwelling women-20-25% with severe symptoms. Clinical practice guidelines recommend individualized pelvic floor muscle training (PFMT) as a first-line treatment for stress or mixed UI in women, although lack of human and financial resources limits delivery of this first-line treatment. Preliminary data suggest that group-based treatments may provide the answer. To date, no adequately powered trials have evaluated the effectiveness or cost-effectiveness of group compared to individual PFMT for UI in older women. Given demographic projections, high prevalence of UI in older women, costly barriers, and group PFMT promising results, there is a clear need to rigorously compare the short- and long-term effectiveness and cost-effectiveness of group vs individual PFMT. The study is designed as a non-inferiority randomized controlled trial, conducted in two facilities (Montreal and Sherbrooke) in the Canadian province of Quebec. Participants include 364 ambulatory, community-dwelling women, aged 60 years and older, with stress or mixed UI. Randomly assigned participants will follow a 12-week PFMT, either in one-on-one sessions or as part of a group, under the supervision of a physiotherapist. Blinded assessments at baseline, immediately post intervention, and at one year will include the seven-day bladder diary, the 24-h pad test, symptoms and quality of life questionnaires, adherence and self-efficacy questionnaire, pelvic floor muscle function, and cost assessments. Primary analysis will test our main hypothesis that group-based treatment is not inferior to individualized treatment with respect to the primary outcome: relative (%) reduction in the number of leakages. Should this study find that a group-based approach is not less effective than individual PFMT, and more cost-effective, this trial will impact positively continence-care accessibility and warrant a change in clinical practice. ClinicalTrials.gov, NCT02039830 . Registered on 12 December 2013; Study protocol version 2; 21 November 2013.
Sexual intercourse for cervical ripening and induction of labour.
Kavanagh, J; Kelly, A J; Thomas, J
2001-01-01
The role of prostaglandins for cervical ripening and induction of labour has been examined extensively. Human semen is the biological source that is presumed to contain the highest prostaglandin concentration. The role of sexual intercourse in the initiation of labour is uncertain. The action of sexual intercourse in stimulating labour is unclear, it may in part be due to the physical stimulation of the lower uterine segment, or endogenous release of oxytocin as a result of orgasm or from the direct action of prostaglandins in semen. Furthermore nipple stimulation may be part of the process of initiation. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. To determine the effects of sexual intercourse for third trimester cervical ripening or induction of labour in comparison with other methods of induction. The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000. (1) clinical trials comparing sexual intercourse for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusion. A strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involves a two-stage method of data extraction. There was one included study of 28 women which reported very limited data, from which no meaningful conclusions can be drawn. The role of sexual intercourse as a method of induction of labour is uncertain. Any future trials investigating sexual intercourse as a method of induction need to be of sufficient power to detect clinically relevant differences in standard outcomes. However, it may prove difficult to standardise sexual intercourse as an intervention to allow meaningful comparisons with other methods of induction of labour.
Johnson, David W.; Brown, Fiona G.; Clarke, Margaret; Boudville, Neil; Elias, Tony J.; Foo, Marjorie W.Y.; Jones, Bernard; Kulkarni, Hemant; Langham, Robyn; Ranganathan, Dwarakanathan; Schollum, John; Suranyi, Michael G.; Tan, Seng H.; Voss, David
2012-01-01
Background The balANZ trial recently reported that neutral pH, low glucose degradation product (biocompatible) peritoneal dialysis (PD) solutions significantly delayed anuria and reduced peritonitis rates compared with conventional solutions. This article reports a secondary outcome analysis of the balANZ trial with respect to peritoneal membrane function. Methods Adult, incident PD patients with residual renal function were randomized to receive either biocompatible or conventional (control) PD solutions for 2 years. Peritoneal equilibration tests were performed at 1, 6, 12, 18 and 24 months. Peritoneal small solute clearances and ultra-filtration (UF) were measured at 3, 6, 9, 12, 18 and 24 months. Results Of the 185 patients recruited into the trial, 85 patients in the Balance group and 82 patients in the control group had peritoneal membrane function evaluated. Mean 4-h dialysate:plasma creatinine ratios (D:P Cr 4h) at 1 month were significantly higher in the Balance group compared with controls (0.67 ± 0.10 versus 0.62 ± 0.10, P = 0.002). Over the 2-year study period, mean D:P Cr 4 h measurements remained stable in the Balance group but increased significantly in controls [difference −0.004 per month, 95% confidence interval (95% CI) −0.005 to −0.002, P < 0.001]. Similar results were obtained for dialysate glucose ratios (D/D0 glucose). Peritoneal UF was significantly lower in the Balance group than in controls at 3 and 6 months. Over the 2-year study period, peritoneal UF increased significantly in the Balance group but remained stable in controls (difference 24 mL/day/month, 95% CI 9–39, P = 0.002). No differences in peritoneal small solute clearances, prescribed dialysate fill volumes or peritoneal glucose exposure were observed between the two groups. Conclusions Biocompatible and conventional PD solutions exert differential effects on peritoneal small solute transport rate and UF over time. Adequately powered trials assessing the impact of these differential membrane effects on PD technique and patient survival rates are warranted. PMID:22859794
Early versus late removal of the laryngeal mask airway (LMA) for general anaesthesia.
Mathew, Preethy J; Mathew, Joseph L
2015-08-10
The laryngeal mask airway (LMA) is a safe and effective modality to maintain the airway for general anaesthesia during surgical procedures. The LMA is removed at the end of surgery and anaesthesia, when the patient maintains an adequate respiratory rate and depth. This removal of the LMA can be done either when the patient is deep under anaesthesia (early removal) or only after the patient has regained consciousness (late removal). It is not clear which of these techniques is superior. The objective of this review was to compare the safety of LMA removal in the deep plane of anaesthesia (early removal) versus removal in the awake state (late removal) for participants undergoing general anaesthesia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (1966 to August 2014); EMBASE (1980 to August 2014); LILACS (1982 to August 2014); CINAHL (WebSPIRS; 1984 to August 2014); and ISI Web of Science (1984 to August 2014). We searched for ongoing trials through various trial registration websites. In addition, we searched conference proceedings and reference lists of relevant articles. We included randomized controlled trials (RCTs) on adults and children undergoing elective general anaesthesia using the LMA, that compared early removal of the LMA (defined as removal of the LMA in the deep plane of anaesthesia) versus late removal of the LMA (defined as removal of the LMA after the patient is awake). Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We used a random-effects model to generate forest plots from the data. We identified a total of 9188 citations and included 15 RCTs conducted on 2242 participants in this review. All trials used the LMA Classic in American Society of Anesthesiologists (ASA) physical status I or II for patients undergoing elective general anaesthesia. Children were enrolled in 11 trials and adults in five trials. None of the trials were of high methodological quality. Eight of the 15 studies had adequate generation of random sequence, whereas only one trial had adequate concealment of random sequence. Three trials had blinded the outcome assessor. Thus, the majority of the studies appeared to have a high risk of bias in the study design.Using the GRADE approach, we found low quality evidence that the risk of laryngospasm was similar with early removal of the LMA (3.3%) versus late removal (2.7%): risk ratio (RR) 1.23, 95% confidence interval (CI) 0.74 to 2.03; 11 trials, 1615 participants. The quality of evidence was very low that the risk of coughing was less after early removal (13.9%) than late removal (19.4%): RR 0.52, 95% CI 0.29 to 0.94; 11 trials, 1430 participants. The quality of evidence for the risk of desaturation was also very low; there was no difference between early removal (7.9%) and late removal (10.1%): RR 0.68, 95% CI 0.4 to 1.16; 13 trials, 2037 participants. We found low quality evidence that the risk of airway obstruction was higher with early removal (15.6%) compared to late removal of the LMA (4.6%): RR 2.69, 95% CI 1.32 to 5.5; eight trials, 1313 participants. This systematic review suggests that current best evidence comparing early versus late removal of the LMA in participants undergoing general anaesthesia does not demonstrate superiority of either intervention. However, the quality of evidence available is either low or very low. There is a paucity of well designed RCTs and a need for large scale RCTs to demonstrate whether early removal or late removal of the LMA is better after general anaesthesia.
Antibiotics for the neurological complications of Lyme disease.
Cadavid, Diego; Auwaerter, Paul G; Rumbaugh, Jeffrey; Gelderblom, Harald
2016-12-08
Various central nervous system-penetrant antibiotics are bactericidal in vitro and in vivo against the causative agent of Lyme neuroborreliosis (LNB), Borrelia burgdorferi. These antibiotics are routinely used clinically to treat LNB, but their relative efficacy is not clear. To assess the effects of antibiotics for the treatment of LNB. On 25 October 2016 we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We searched clinical trial registers on 26 October 2016. We reviewed the bibliographies of the randomized trials identified and contacted the authors and known experts in the field to identify additional published or unpublished data. There were no language restrictions when searching for studies. Randomized clinical trials of antibiotic treatment of LNB in adults and children that compared any antibiotic treatment, including combinations of treatments, versus any other treatment, placebo, or no treatment. We excluded studies of entities considered as post-Lyme syndrome. We used standard methodological procedures expected by Cochrane. We identified seven randomized studies involving 450 European participants with LNB for inclusion in this systematic review. We found no trials conducted in the United States. Marked heterogeneity among these studies prevented meta-analysis. None of the studies included a placebo control on the initial antibiotic treatment, and only one was blinded. None were delayed-start studies. All were active comparator studies, and most were not adequately powered for non-inferiority comparison. The trials investigated four antibiotics: penicillin G and ceftriaxone in four studies, doxycycline in three studies, and cefotaxime in two studies. One study tested a three-month course of oral amoxicillin versus placebo following initial treatment with intravenous ceftriaxone. One study was limited to children. The trials measured efficacy using heterogeneous physician- or patient-reported outcomes, or both. In some cases cerebrospinal fluid analysis was included as an indirect biomarker of disease and outcome. None of the studies reported on our proposed primary outcome, 'Improvement in a measure of overall disability in the long term (three or more months).' None of the trials revealed any between-group differences in symptom resolution in response to active treatment. In general, treatment was tolerated well. The quality of adverse event reporting, however, was low. There is mostly low- to very low-quality clinical evidence from a limited number of mostly small, heterogeneous trials with diverse outcome measures, comparing the relative efficacy of central nervous system-penetrant antibiotics for the treatment of LNB. The few existing randomized studies have limited power and lack consistent and well-defined entry criteria and efficacy endpoints. It is not possible to draw firm conclusions on the relative efficacy of accepted antibiotic drug regimens for the treatment of LNB. The majority of people are reported to have good outcomes, and symptoms resolve by 12 months regardless of the antibiotic used. A minority of participants did not improve sufficiently, and some were retreated. These randomized studies provide some evidence that doxycycline, penicillin G, ceftriaxone, and cefotaxime are efficacious in the treatment of European LNB. No evidence of additional efficacy was observed when, in one study, an initial antibiotic treatment with intravenous ceftriaxone was followed by additional longer treatment with oral amoxicillin. There is a lack of evidence identified through our high-quality search strategy on the efficacy of antibiotics for treatment of LNB in the United States.
Yeh, Hsin-Chieh; Clark, Jeanne M; Emmons, Karen E; Moore, Reneé H; Bennett, Gary G; Warner, Erica T; Sarwer, David B; Jerome, Gerald J; Miller, Edgar R; Volger, Sheri; Louis, Thomas A; Wells, Barbara; Wadden, Thomas A; Colditz, Graham A; Appel, Lawrence J
2010-08-01
The National Heart, Lung, and Blood Institute (NHLBI) funded three institutions to conduct effectiveness trials of weight loss interventions in primary care settings. Unlike traditional multi-center clinical trials, each study was established as an independent trial with a distinct protocol. Still, efforts were made to coordinate and standardize several aspects of the trials. The three trials formed a collaborative group, the 'Practice-based Opportunities for Weight Reduction (POWER) Trials Collaborative Research Group.' We describe the common and distinct features of the three trials, the key characteristics of the collaborative group, and the lessons learned from this novel organizational approach. The Collaborative Research Group consists of three individual studies: 'Be Fit, Be Well' (Washington University in St. Louis/Harvard University), 'POWER Hopkins' (Johns Hopkins), and 'POWER-UP' (University of Pennsylvania). There are a total of 15 participating clinics with ~1100 participants. The common primary outcome is change in weight at 24 months of follow-up, but each protocol has trial-specific elements including different interventions and different secondary outcomes. A Resource Coordinating Unit at Johns Hopkins provides administrative support. The Collaborative Research Group established common components to facilitate potential cross-site comparisons. The main advantage of this approach is to develop and evaluate several interventions, when there is insufficient evidence to test one or two approaches, as would be done in a traditional multi-center trial. The challenges of the organizational design include the complex decision-making process, the extent of potential data pooling, time intensive efforts to standardize reports, and the additional responsibilities of the DSMB to monitor three distinct protocols.
Is Vertical Jump Height an Indicator of Athletes' Power Output in Different Sport Modalities?
Kons, Rafael L; Ache-Dias, Jonathan; Detanico, Daniele; Barth, Jonathan; Dal Pupo, Juliano
2018-03-01
Kons, RL, Ache-Dias, J, Detanico, D, Barth, J, and Dal Pupo, J. Is vertical jump height an indicator of athletes' power output in different sports modalities? J Strength Cond Res 32(3): 708-715, 2018-This study aimed to identify whether the ratio standard is adequate for the scaling of peak power output (PPO) for body mass (BM) in athletes of different sports and to verify classification agreement for athletes involved in different sports using PPO scaled for BM and jump height (JH). One hundred and twenty-four male athletes divided into 3 different groups-combat sports, team sports, and runners-participated in this study. Participants performed the countermovement jump on a force plate. Peak power output and JH were calculated from the vertical ground reaction force. We found different allometric exponents for each modality, allowing the use of the ratio standard for team sports. For combat sports and runners, the ratio standard was not considered adequate, and therefore, a specific allometric exponent for these 2 groups was found. Significant correlations between adjusted PPO for BM (PPOADJ) and JH were found for all modalities, but it was higher for runners (r = 0.81) than team and combat sports (r = 0.63 and 0.65, respectively). Moderate agreement generated by the PPOADJ and JH was verified in team sports (k = 0.47) and running (k = 0.55) and fair agreement in combat sports (k = 0.29). We conclude that the ratio standard seems to be suitable only for team sports; for runners and combat sports, an allometric model seems adequate. The use of JH as an indicator of power output may be considered reasonable only for runners.
Randomized trials published in some Chinese journals: how many are randomized?
Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David
2009-07-02
The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9-7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18-2.13, and relative risk 14.42, 95% confidence interval 9.40-22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83-14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0-81.0). Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing to a lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed.
Randomized trials published in some Chinese journals: how many are randomized?
Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David
2009-01-01
Background The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. Methods The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. Results From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9–7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18–2.13, and relative risk 14.42, 95% confidence interval 9.40–22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83–14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0–81.0). Conclusion Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing toa lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed. PMID:19573242
Watanabe, Norio; Horikoshi, Masaru; Yamada, Mitsuhiko; Shimodera, Shinji; Akechi, Tatsuo; Miki, Kazuhira; Inagaki, Masatoshi; Yonemoto, Naohiro; Imai, Hissei; Tajika, Aran; Ogawa, Yusuke; Takeshima, Nozomi; Hayasaka, Yu; Furukawa, Toshi A
2015-07-07
Major depression is one of the most debilitating diseases in terms of quality of life. Less than half of patients suffering from depression can achieve remission after adequate antidepressant treatment. Another promising treatment option is cognitive-behavior therapy (CBT). However, the need for experienced therapists and substantive dedicated time prevent CBT from being widely disseminated. In the present study, we aim to examine the effectiveness of switching antidepressants and starting a smartphone-based CBT program at the same time, in comparison to switching antidepressants only, among patients still suffering from depression after adequate antidepressant treatment. A multi-center randomized trial is currently being conducted since September 2014. The smartphone-based CBT program, named the "Kokoro-App," for major depression has been developed and its feasibility has been confirmed in a previous open study. The program consists of an introduction, 6 sessions and an epilogue, and is expected to be completed within 9 weeks by patients. In the present trial, 164 patients with DSM-5 major depressive disorder and still suffering from depressive symptoms after adequate antidepressant treatment for more than 4 weeks will be allocated to the Kokoro-App plus switching antidepressant group or the switching antidepressant alone group. The participants allocated to the latter group will receive full components of the Kokoro-App after 9 weeks. The primary outcome is the change in the total score on the Patient Health Questionnaire through the 9 weeks of the program, as assessed at week 0, 1, 5 and 9 via telephone by blinded raters. The secondary outcomes include the change in the total score of the Beck Depression Inventory-II, change in side effects as assessed by the Frequency, Intensity and Burden of Side Effects Rating, and treatment satisfaction. An effective and reachable intervention may not only lead to healthier mental status among depressed patients, but also to reduced social burden from this illness. This paper outlines the background and methods of a trial that evaluates the possible additive value of a smartphone-based CBT program for treatment-resistant depression. UMIN-CTR: UMIN000013693 (registered on 1 June 2014).
Discourse in Courts: Cooperation, Coercion, and Coherence.
ERIC Educational Resources Information Center
Penman, Robyn
1987-01-01
Investigates the relevance of a Gricean model for accounting for coherent discourse in courts of law. Identifies 19 rules of discourse congruent with Grice's Cooperative Principle in transcripts of eight trials. However, finds courts must coerce participants to be cooperative. Concludes that Grice's theory does not account adequately for coherent…
Trial by Fire (and Tornado) Taught Us to Plan for Crises.
ERIC Educational Resources Information Center
Caylor, Mary Jane
1991-01-01
Based on Huntsville (Alabama) schools' experience with a devastating fire, the superintendent later ensured adequate fire insurance coverage, promoted regular fire drills, and developed an emergency response plan that delineated staff responsibilities, communication modes, and training and updating procedures. The plan served the district well…
Value of fluid fertilizer in bio-energy production
USDA-ARS?s Scientific Manuscript database
In field trials, analysis of whole corn plants at V6 and ear leaves at mid-silk showed adequate levels of all macronutrients, which suggests that nutrient management was balanced both for conventional and intensively managed (twin-row) planting scenarios and the amount of stover removed from the fie...
Adapting Mindfulness-Based Cognitive Therapy for Treatment-Resistant Depression
ERIC Educational Resources Information Center
Eisendrath, Stuart; Chartier, Maggie; McLane, Maura
2011-01-01
Major depressive disorder (MDD) is currently ranked the third leading cause of disability in the world. Treatment-resistant depression (TRD) causes the majority of MDD disability. Strikingly, 50% of individuals with MDD will fail to remit with 2 adequate trials of antidepressant medications, thus qualifying as treatment resistant. Current…
NASA Technical Reports Server (NTRS)
Chapman, C. P.; Chapman, P. D.; Lewison, A. H.
1982-01-01
A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.
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.
Washout policies in long-term indwelling urinary catheterisation in adults.
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.
Asikanius, Elina; Rufibach, Kaspar; Bahlo, Jasmin; Bieska, Gabriele; Burger, Hans Ulrich
2016-11-01
To optimize resources, randomized clinical trials with multiple arms can be an attractive option to simultaneously test various treatment regimens in pharmaceutical drug development. The motivation for this work was the successful conduct and positive final outcome of a three-arm randomized clinical trial primarily assessing whether obinutuzumab plus chlorambucil in patients with chronic lympocytic lymphoma and coexisting conditions is superior to chlorambucil alone based on a time-to-event endpoint. The inference strategy of this trial was based on a closed testing procedure. We compare this strategy to three potential alternatives to run a three-arm clinical trial with a time-to-event endpoint. The primary goal is to quantify the differences between these strategies in terms of the time it takes until the first analysis and thus potential approval of a new drug, number of required events, and power. Operational aspects of implementing the various strategies are discussed. In conclusion, using a closed testing procedure results in the shortest time to the first analysis with a minimal loss in power. Therefore, closed testing procedures should be part of the statistician's standard clinical trials toolbox when planning multiarm clinical trials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Pan, Haitao; Yuan, Ying; Xia, Jielai
2017-11-01
A biosimilar refers to a follow-on biologic intended to be approved for marketing based on biosimilarity to an existing patented biological product (i.e., the reference product). To develop a biosimilar product, it is essential to demonstrate biosimilarity between the follow-on biologic and the reference product, typically through two-arm randomization trials. We propose a Bayesian adaptive design for trials to evaluate biosimilar products. To take advantage of the abundant historical data on the efficacy of the reference product that is typically available at the time a biosimilar product is developed, we propose the calibrated power prior, which allows our design to adaptively borrow information from the historical data according to the congruence between the historical data and the new data collected from the current trial. We propose a new measure, the Bayesian biosimilarity index, to measure the similarity between the biosimilar and the reference product. During the trial, we evaluate the Bayesian biosimilarity index in a group sequential fashion based on the accumulating interim data, and stop the trial early once there is enough information to conclude or reject the similarity. Extensive simulation studies show that the proposed design has higher power than traditional designs. We applied the proposed design to a biosimilar trial for treating rheumatoid arthritis.
Simultaneous sequential monitoring of efficacy and safety led to masking of effects.
van Eekelen, Rik; de Hoop, Esther; van der Tweel, Ingeborg
2016-08-01
Usually, sequential designs for clinical trials are applied on the primary (=efficacy) outcome. In practice, other outcomes (e.g., safety) will also be monitored and influence the decision whether to stop a trial early. Implications of simultaneous monitoring on trial decision making are yet unclear. This study examines what happens to the type I error, power, and required sample sizes when one efficacy outcome and one correlated safety outcome are monitored simultaneously using sequential designs. We conducted a simulation study in the framework of a two-arm parallel clinical trial. Interim analyses on two outcomes were performed independently and simultaneously on the same data sets using four sequential monitoring designs, including O'Brien-Fleming and Triangular Test boundaries. Simulations differed in values for correlations and true effect sizes. When an effect was present in both outcomes, competition was introduced, which decreased power (e.g., from 80% to 60%). Futility boundaries for the efficacy outcome reduced overall type I errors as well as power for the safety outcome. Monitoring two correlated outcomes, given that both are essential for early trial termination, leads to masking of true effects. Careful consideration of scenarios must be taken into account when designing sequential trials. Simulation results can help guide trial design. Copyright © 2016 Elsevier Inc. All rights reserved.
Effect of recovery interventions on cycling performance and pacing strategy in the heat.
De Pauw, Kevin; Roelands, Bart; Vanparijs, Jef; Meeusen, Romain
2014-03-01
To determine the effect of active recovery (AR), passive rest (PR), and cold-water immersion (CWI) after 90 min of intensive cycling on a subsequent 12-min time trial (TT2) and the applied pacing strategy in TT2. After a maximal test and familiarization trial, 9 trained male subjects (age 22 ± 3 y, VO2max 62.1 ± 5.3 mL · min-1 · kg-1) performed 3 experimental trials in the heat (30°C). Each trial consisted of 2 exercise tasks separated by 1 h. The first was a 60-min constant-load trial at 55% of the maximal power output followed by a 30-min time trial (TT1). The second comprised a 12-min simulated time trial (TT2). After TT1, AR, PR, or CWI was applied for 15 min. No significant TT2 performance differences were observed, but a 1-sample t test (within each condition) revealed different pacing strategies during TT2. CWI resulted in an even pacing strategy, while AR and PR resulted in a gradual decline of power output after the onset of TT2 (P ≤ .046). During recovery, AR and CWI showed a trend toward faster blood lactate ([BLa]) removal, but during TT2 significantly higher [BLa] was only observed after CWI compared with PR (P = .011). The pacing strategy during subsequent cycling performance in the heat is influenced by the application of different postexercise recovery interventions. Although power was not significantly altered between groups, CWI enabled a differently shaped power profile, likely due to decreased thermal strain.
Contralateral Delay Activity Tracks Fluctuations in Working Memory Performance.
Adam, Kirsten C S; Robison, Matthew K; Vogel, Edward K
2018-01-08
Neural measures of working memory storage, such as the contralateral delay activity (CDA), are powerful tools in working memory research. CDA amplitude is sensitive to working memory load, reaches an asymptote at known behavioral limits, and predicts individual differences in capacity. An open question, however, is whether neural measures of load also track trial-by-trial fluctuations in performance. Here, we used a whole-report working memory task to test the relationship between CDA amplitude and working memory performance. If working memory failures are due to decision-based errors and retrieval failures, CDA amplitude would not differentiate good and poor performance trials when load is held constant. If failures arise during storage, then CDA amplitude should track both working memory load and trial-by-trial performance. As expected, CDA amplitude tracked load (Experiment 1), reaching an asymptote at three items. In Experiment 2, we tracked fluctuations in trial-by-trial performance. CDA amplitude was larger (more negative) for high-performance trials compared with low-performance trials, suggesting that fluctuations in performance were related to the successful storage of items. During working memory failures, participants oriented their attention to the correct side of the screen (lateralized P1) and maintained covert attention to the correct side during the delay period (lateralized alpha power suppression). Despite the preservation of attentional orienting, we found impairments consistent with an executive attention theory of individual differences in working memory capacity; fluctuations in executive control (indexed by pretrial frontal theta power) may be to blame for storage failures.
78 FR 46549 - Approval and Promulgation of Implementation Plans; Idaho: State Board Requirements
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-01
... such board or body or the head of an executive agency with similar powers be adequately disclosed.'' 42... Requirements Idaho Code Sec. 39-107, Board--Composition--Officers-- Compensation--Powers--Subpoena--Depositions... regard to their knowledge of and interest in solid waste; two (2) members shall be chosen for their...
The Power of the Test for Treatment Effects in Three-Level Block Randomized Designs
ERIC Educational Resources Information Center
Konstantopoulos, Spyros
2008-01-01
Experiments that involve nested structures may assign treatment conditions either to subgroups (such as classrooms) or individuals within subgroups (such as students). The design of such experiments requires knowledge of the intraclass correlation structure to compute the sample sizes necessary to achieve adequate power to detect the treatment…
reflect it. There are commercially available manual and powered suction devices on the market , and several are specifically advertised for use in...combine to suggest that no device on the market meets even the most basic requirements of being small, lightweight, rugged, and demonstrating adequate
A Bayesian adaptive design for biomarker trials with linked treatments.
Wason, James M S; Abraham, Jean E; Baird, Richard D; Gournaris, Ioannis; Vallier, Anne-Laure; Brenton, James D; Earl, Helena M; Mander, Adrian P
2015-09-01
Response to treatments is highly heterogeneous in cancer. Increased availability of biomarkers and targeted treatments has led to the need for trial designs that efficiently test new treatments in biomarker-stratified patient subgroups. We propose a novel Bayesian adaptive randomisation (BAR) design for use in multi-arm phase II trials where biomarkers exist that are potentially predictive of a linked treatment's effect. The design is motivated in part by two phase II trials that are currently in development. The design starts by randomising patients to the control treatment or to experimental treatments that the biomarker profile suggests should be active. At interim analyses, data from treated patients are used to update the allocation probabilities. If the linked treatments are effective, the allocation remains high; if ineffective, the allocation changes over the course of the trial to unlinked treatments that are more effective. Our proposed design has high power to detect treatment effects if the pairings of treatment with biomarker are correct, but also performs well when alternative pairings are true. The design is consistently more powerful than parallel-groups stratified trials. This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously.
Royston, Patrick; Parmar, Mahesh K B
2016-02-11
Most randomized controlled trials with a time-to-event outcome are designed assuming proportional hazards (PH) of the treatment effect. The sample size calculation is based on a logrank test. However, non-proportional hazards are increasingly common. At analysis, the estimated hazards ratio with a confidence interval is usually presented. The estimate is often obtained from a Cox PH model with treatment as a covariate. If non-proportional hazards are present, the logrank and equivalent Cox tests may lose power. To safeguard power, we previously suggested a 'joint test' combining the Cox test with a test of non-proportional hazards. Unfortunately, a larger sample size is needed to preserve power under PH. Here, we describe a novel test that unites the Cox test with a permutation test based on restricted mean survival time. We propose a combined hypothesis test based on a permutation test of the difference in restricted mean survival time across time. The test involves the minimum of the Cox and permutation test P-values. We approximate its null distribution and correct it for correlation between the two P-values. Using extensive simulations, we assess the type 1 error and power of the combined test under several scenarios and compare with other tests. We investigate powering a trial using the combined test. The type 1 error of the combined test is close to nominal. Power under proportional hazards is slightly lower than for the Cox test. Enhanced power is available when the treatment difference shows an 'early effect', an initial separation of survival curves which diminishes over time. The power is reduced under a 'late effect', when little or no difference in survival curves is seen for an initial period and then a late separation occurs. We propose a method of powering a trial using the combined test. The 'insurance premium' offered by the combined test to safeguard power under non-PH represents about a single-digit percentage increase in sample size. The combined test increases trial power under an early treatment effect and protects power under other scenarios. Use of restricted mean survival time facilitates testing and displaying a generalized treatment effect.
Trial Frame Refraction versus Autorefraction among New Patients in a Low-Vision Clinic
DeCarlo, Dawn K.; McGwin, Gerald; Searcey, Karen; Gao, Liyan; Snow, Marsha; Waterbor, John; Owsley, Cynthia
2013-01-01
Purpose. To determine the relationship between refractive error as measured by autorefraction and that measured by trial frame refraction among a sample of adults with vision impairment seen in a university-based low-vision clinic and to determine if autorefraction might be a suitable replacement for trial frame refraction. Methods. A retrospective chart review of all new patients 19 years or older seen over an 18-month period was conducted and the following data collected: age, sex, primary ocular diagnosis, entering distance visual acuity, habitual correction, trial frame refraction, autorefraction, and distance visual acuity measured after trial frame refraction. Trial frame refraction and autorefraction were compared using paired t-tests, intraclass correlations, and Bland-Altman plots. Results. Final analyses included 440 patients for whom both trial frame refraction and autorefraction data were available for the better eye. Participants were mostly female (59%) with a mean age of 68 years (SD = 20). Age-related macular degeneration was the most common etiology for vision impairment (44%). Values for autorefraction and trial frame refraction were statistically different, but highly correlated for the spherical equivalent power (r = 0.92), the cylinder power (r = 0.80) and overall blurring strength (0.89). Although the values of the cross-cylinders J0 and J45 were similar, they were poorly correlated (0.08 and 0.15, respectively). The range of differences in spherical equivalent power was large (−8.6 to 4.9). Conclusions. Autorefraction is highly correlated with trial frame refraction. Differences are sometimes substantial, making autorefraction an unsuitable substitute for trial frame refraction. PMID:23188726
Trial frame refraction versus autorefraction among new patients in a low-vision clinic.
DeCarlo, Dawn K; McGwin, Gerald; Searcey, Karen; Gao, Liyan; Snow, Marsha; Waterbor, John; Owsley, Cynthia
2013-01-02
To determine the relationship between refractive error as measured by autorefraction and that measured by trial frame refraction among a sample of adults with vision impairment seen in a university-based low-vision clinic and to determine if autorefraction might be a suitable replacement for trial frame refraction. A retrospective chart review of all new patients 19 years or older seen over an 18-month period was conducted and the following data collected: age, sex, primary ocular diagnosis, entering distance visual acuity, habitual correction, trial frame refraction, autorefraction, and distance visual acuity measured after trial frame refraction. Trial frame refraction and autorefraction were compared using paired t-tests, intraclass correlations, and Bland-Altman plots. Final analyses included 440 patients for whom both trial frame refraction and autorefraction data were available for the better eye. Participants were mostly female (59%) with a mean age of 68 years (SD = 20). Age-related macular degeneration was the most common etiology for vision impairment (44%). Values for autorefraction and trial frame refraction were statistically different, but highly correlated for the spherical equivalent power (r = 0.92), the cylinder power (r = 0.80) and overall blurring strength (0.89). Although the values of the cross-cylinders J(0) and J(45) were similar, they were poorly correlated (0.08 and 0.15, respectively). The range of differences in spherical equivalent power was large (-8.6 to 4.9). Autorefraction is highly correlated with trial frame refraction. Differences are sometimes substantial, making autorefraction an unsuitable substitute for trial frame refraction.
Hot rocket plume experiment - Survey and conceptual design. [of rhenium-iridium bipropellants
NASA Technical Reports Server (NTRS)
Millard, Jerry M.; Luan, Taylor W.; Dowdy, Mack W.
1992-01-01
Attention is given to a space-borne engine plume experiment study to fly an experiment which will both verify and quantify the reduced contamination from advanced rhenium-iridium earth-storable bipropellant rockets (hot rockets) and provide a correlation between high-fidelity, in-space measurements and theoretical plume and surface contamination models. The experiment conceptual design is based on survey results from plume and contamination technologists throughout the U.S. With respect to shuttle use, cursory investigations validate Hitchhiker availability and adaptability, adequate remote manipulator system (RMS) articulation and dynamic capability, acceptable RMS attachment capability, adequate power and telemetry capability, and adequate flight altitude and attitude/orbital capability.
Rohan, Kelly J; Evans, Maggie; Mahon, Jennifer N; Sitnikov, Lilya; Ho, Sheau-Yan; Nillni, Yael I; Postolache, Teodor T; Vacek, Pamela M
2013-03-21
Seasonal affective disorder (SAD) is a subtype of recurrent depression involving major depressive episodes during the fall and/or winter months that remit in the spring. The central public health challenge in the management of SAD is prevention of winter depression recurrence. Light therapy (LT) is the established and best available acute SAD treatment. However, long-term compliance with daily LT from first symptom through spontaneous springtime remission every fall/winter season is poor. Time-limited alternative treatments with effects that endure beyond the cessation of acute treatment are needed to prevent the annual recurrence of SAD. This is an NIMH-funded R01-level randomized clinical trial to test the efficacy of a novel, SAD-tailored cognitive-behavioral group therapy (CBT) against LT in a head-to-head comparison on next winter outcomes. This project is designed to test for a clinically meaningful difference between CBT and LT on depression recurrence in the next winter (the primary outcome). This is a concurrent two-arm study that will randomize 160 currently symptomatic community adults with major depression, recurrent with seasonal pattern, to CBT or LT. After 6 weeks of treatment in the initial winter, participants are followed in the subsequent summer, the next winter, and two winters later. Key methodological issues surround timing study procedures for a predictably recurrent and time-limited disorder with a focus on long-term outcomes. The chosen design answers the primary question of whether prior exposure to CBT is associated with a substantially lower likelihood of depression recurrence the next winter than LT. This design does not test the relative contributions of the cognitive-behavioral treatment components vs. nonspecific factors to CBT's outcomes and is not adequately powered to test for differences or equivalence between cells at treatment endpoint. Alternative designs addressing these limitations would have required more patients, increased costs, and reduced power to detect a difference in the primary outcome. Clinicaltrials.gov identifier NCT01714050.
Drozdov, Daniel; Thomer, Anja; Meili, Marc; Schwarz, Stefanie; Kouegbe, Rita Bossart; Regez, Katharina; Guglielmetti, Merih; Schild, Ursula; Conca, Antoinette; Schäfer, Petra; Reutlinger, Barbara; Ottiger, Cornelia; Buchkremer, Florian; Litke, Alexander; Schuetz, Philipp; Huber, Andreas; Bürgi, Ulrich; Fux, Christoph A; Bock, Andreas; Müller, Beat; Albrich, Werner C
2013-03-22
Urinary tract infections (UTIs) are among the most common infectious diseases and drivers of antibiotic use and in-hospital days. A reduction of antibiotic use potentially lowers the risk of antibiotic resistance. An early and adequate risk assessment combining medical, biopsychosocial and functional risk scores has the potential to optimize site-of-care decisions and thus allocation of limited health-care resources. The aim of this factorial design study is twofold: first, for Intervention A, it investigates antibiotic exposure of patients treated with a protocol based on the type of UTI, procalcitonin (PCT) and pyuria. Second, for Intervention B, it investigates the usefulness of the prognostic biomarker proadrenomedullin (ProADM) integrated into an interdisciplinary assessment bundle for site-of-care decisions. This randomized controlled open-label trial has a factorial design (2 × 2). Randomization of patients will be based on a pre-specified computer-generated randomization list and independent for the two interventions. Adults with UTI presenting to the emergency department (ED) will be screened and enrolled after providing informed consent. For our first Intervention (A), we developed a protocol based on previous observational research to recommend initiation and duration of antibiotic use based on the clinical presentation of UTI, pyuria and PCT levels. For our second intervention (B), an algorithm was developed to support site-of care decisions based on the prognostic marker ProADM and distinct nursing factors on days 1 and 3. Both interventions will be compared with a control group conforming to the guidelines. The primary endpoints for the two interventions will be: (A) overall exposure to antibiotics and (B) length of physician-led hospitalization within a follow-up of 30 days. Endpoints are assessed at discharge from hospital, and 30 and 90 days after admission. We plan to screen 300 patients and enroll 250 for an anticipated estimated loss of follow-up of 20%. This will provide adequate power for the two interventions. This trial investigates two strategies for improved individualized medical care in patients with UTI. The minimally effective duration of antibiotic therapy is not known for UTIs, which is important for reducing the selection pressure for antibiotic resistance, costs and drug-related side effects. Triage decisions must be improved to reflect the true medical, biopsychosocial and functional risks in order to allocate patients to the most appropriate care setting and reduce hospital-acquired disability. ISRCTN13663741.
Sutherland, Jennifer; Barnard, Sharmani; Wynne, Aileen; Rezel, Emma; Doel, Andrew; Grigsby-Duffy, Lily; Edwards, Suzanne; Russell, Sophie; Hotopf, Ellie; Perel, Pablo; Free, Caroline
2018-01-01
Background We conducted a systematic review to assess the effectiveness of smoking cessation, physical activity (PA), diet, and alcohol reduction interventions delivered by mobile technology to prevent non-communicable diseases (NCDs). Methods We searched for randomised controlled trials (RCTs) of mobile-based NCD prevention interventions using MEDLINE, EMBASE, Global Health, CINAHL (Jan 1990–Jan 2016). Two authors extracted data. Findings 71 trials were included: smoking cessation (n = 18); PA (n = 15), diet (n = 3), PA and diet (n = 25); PA, diet, and smoking cessation (n = 2); and harmful alcohol consumption (n = 8). 4 trials had low risk of bias. The effect of SMS-based smoking cessation support on biochemically verified continuous abstinence was pooled relative risk [RR] 2.19 [95% CI 1.80–2.68], I2 = 0%) and on verified 7 day point prevalence of smoking cessation was pooled RR 1.51 [95% CI 1.06–2.15], I2 = 0%, with no reported adverse events. There was no difference in peak oxygen intake at 3 months in a trial of an SMS-based PA intervention. The effect of SMS-based diet and PA interventions on: incidence of diabetes was pooled RR 0.67 [95% CI 0.49, 0.90], I2 = 0.0%; end-point weight was pooled MD -0.99Kg [95% CI -3.63, 1.64] I2 = 29.4%; % change in weight was pooled MD -3.1 [95%CI -4.86- -1.3] I2 0.3%; and on triglyceride levels was pooled MD -0.19 mmol/L [95% CI -0.29, -0.08], I2 = 0.0%. The results of other pooled analyses of the effect of SMS-based diet and PA interventions were heterogenous (I2 59–90%). The effects of alcohol reduction interventions were inconclusive. Conclusions Smoking cessation support delivered by SMS increases quitting rates. Trials of PA interventions reporting outcomes ≥3 months showed no benefits. There were at best modest benefits of diet and PA interventions. The effects of the most promising SMS-based smoking, diet and PA interventions on morbidity and mortality in high-risk groups should be established in adequately powered RCTs. PMID:29304148
Palmer, Melissa; Sutherland, Jennifer; Barnard, Sharmani; Wynne, Aileen; Rezel, Emma; Doel, Andrew; Grigsby-Duffy, Lily; Edwards, Suzanne; Russell, Sophie; Hotopf, Ellie; Perel, Pablo; Free, Caroline
2018-01-01
We conducted a systematic review to assess the effectiveness of smoking cessation, physical activity (PA), diet, and alcohol reduction interventions delivered by mobile technology to prevent non-communicable diseases (NCDs). We searched for randomised controlled trials (RCTs) of mobile-based NCD prevention interventions using MEDLINE, EMBASE, Global Health, CINAHL (Jan 1990-Jan 2016). Two authors extracted data. 71 trials were included: smoking cessation (n = 18); PA (n = 15), diet (n = 3), PA and diet (n = 25); PA, diet, and smoking cessation (n = 2); and harmful alcohol consumption (n = 8). 4 trials had low risk of bias. The effect of SMS-based smoking cessation support on biochemically verified continuous abstinence was pooled relative risk [RR] 2.19 [95% CI 1.80-2.68], I2 = 0%) and on verified 7 day point prevalence of smoking cessation was pooled RR 1.51 [95% CI 1.06-2.15], I2 = 0%, with no reported adverse events. There was no difference in peak oxygen intake at 3 months in a trial of an SMS-based PA intervention. The effect of SMS-based diet and PA interventions on: incidence of diabetes was pooled RR 0.67 [95% CI 0.49, 0.90], I2 = 0.0%; end-point weight was pooled MD -0.99Kg [95% CI -3.63, 1.64] I2 = 29.4%; % change in weight was pooled MD -3.1 [95%CI -4.86- -1.3] I2 0.3%; and on triglyceride levels was pooled MD -0.19 mmol/L [95% CI -0.29, -0.08], I2 = 0.0%. The results of other pooled analyses of the effect of SMS-based diet and PA interventions were heterogenous (I2 59-90%). The effects of alcohol reduction interventions were inconclusive. Smoking cessation support delivered by SMS increases quitting rates. Trials of PA interventions reporting outcomes ≥3 months showed no benefits. There were at best modest benefits of diet and PA interventions. The effects of the most promising SMS-based smoking, diet and PA interventions on morbidity and mortality in high-risk groups should be established in adequately powered RCTs.
Straker, Leon M; Abbott, Rebecca A; Piek, Jan P; Pollock, Clare M; Davies, Peter S; Smith, Anne J
2009-01-01
Background Many children are reported to have insufficient physical activity (PA) placing them at greater risk of poor health outcomes. Participating in sedentary activities such as playing electronic games is widely believed to contribute to less PA. However there is no experimental evidence that playing electronic games reduces PA. There is also no evidence regarding the effect of different types of electronic games (traditional sedentary electronic games versus new active input electronic games) on PA. Further, there is a poor understanding about how characteristics of children may moderate the impact of electronic game access on PA and about what leisure activities are displaced when children play electronic games. Given that many children play electronic games, a better understanding of the effect of electronic game use on PA is critical to inform child health policy and intervention. Methods This randomised and controlled trial will examine whether PA is decreased by access to electronic games and whether any effect is dependent on the type of game input or the child's characteristics. Children aged 10–12 years (N = 72, 36 females) will be recruited and randomised to a balanced ordering of 'no electronic games', 'traditional' electronic games and 'active' electronic games. Each child will participate in each condition for 8 weeks, and be assessed prior to participation and at the end of each condition. The primary outcome is PA, assessed by Actical accelerometers worn for 7 days on the wrist and hip. Energy expenditure will be assessed by the doubly labelled water technique and motor coordination, adiposity, self-confidence, attitudes to technology and PA and leisure activities will also be assessed. A sample of 72 will provide a power of > 0.9 for detecting a 15 mins difference in PA (sd = 30 mins). Discussion This is the first such trial and will provide critical information to understand whether access to electronic games affects children's PA. Given the vital importance of adequate PA to a healthy start to life and establishing patterns which may track into adulthood, this project can inform interventions which could have a profound impact on the long term health of children. Trial registration This trial is registered in the Australia and New Zealand Clinical Trials Registry (ACTRN 12609000279224). PMID:19563680
2010-01-01
Background Competing causes of mortality in the elderly decrease the potential net benefit from colorectal cancer screening and increase the likelihood of potential harms. Individualized decision making has been recommended, so that the elderly can decide whether or not to undergo colorectal cancer (CRC) screening. The objective is to develop and test a decision aid designed to promote individualized colorectal cancer screening decision making for adults age 75 and over. Methods We used formative research and cognitive testing to develop and refine the decision aid. We then tested the decision aid in an uncontrolled trial. The primary outcome was the proportion of patients who were prepared to make an individualized decision, defined a priori as having adequate knowledge (10/15 questions correct) and clear values (25 or less on values clarity subscale of decisional conflict scale). Secondary outcomes included overall score on the decisional conflict scale, and preferences for undergoing screening. Results We enrolled 46 adults in the trial. The decision aid increased the proportion of participants with adequate knowledge from 4% to 52% (p < 0.01) and the proportion prepared to make an individualized decision from 4% to 41% (p < 0.01). The proportion that preferred to undergo CRC screening decreased from 67% to 61% (p = 0. 76); 7 participants (15%) changed screening preference (5 against screening, 2 in favor of screening) Conclusion In an uncontrolled trial, the elderly participants appeared better prepared to make an individualized decision about whether or not to undergo CRC screening after using the decision aid. PMID:20849625
Vaginal delivery after previous caesarean section: is X-ray pelvimetry necessary?
Thubisi, M; Ebrahim, A; Moodley, J; Shweni, P M
1993-05-01
To determine whether antepartum X-ray pelvimetry (XRP) reliably identified women suitable for a trial labour or repeat elective caesarean section after one previous section. A prospective controlled trial in which women were randomly allocated to either an antepartum XRP group who had XRP at 36 weeks gestation to determine mode of delivery, or a control group who had a trial labour without antepartum XRP. Following delivery, all controls had postpartum XRP. Department of Obstetrics and Gynaecology, King Edward VIII Hospital, Durban, South Africa. Three hundred-six women with a history of one previous caesarean section. Mode of delivery, birthweight and maternal and perinatal mortality and morbidity in the two groups. In the antepartum XRP group, 23 of 144 (16%) of women delivered vaginally compared with 60 of 144 (42%) controls (P < 0.0001). Of the 84 women with adequate antepartum XRP only 23 (27.7%) delivered vaginally. In the control group, 33 of 60 (55%) women who had vaginal deliveries had inadequate postpartum XRP and would have had a caesarean section if this information was known in the antepartum period; 62 of 84 (74%) caesarean sections in the control group had adequate postpartum XRP. Birthweight of the infants was similar in the two groups. There were no maternal or perinatal deaths. Maternal morbidity was similar in the two groups. Neonatal morbidity was minimal. Antepartum XRP is not necessary prior to a trial labour in women with one previous caesarean section. It increases the caesarean section rate and is a poor predictor of the outcome of labour.
Gordon, Kenneth B; Betts, Keith A; Sundaram, Murali; Signorovitch, James E; Li, Junlong; Xie, Meng; Wu, Eric Q; Okun, Martin M
2017-12-01
Most methotrexate-treated psoriasis patients do not achieve a long-term PASI75 (75% reduction from baseline Psoriasis Area and Severity Index score) response. Indications of nonresponse can be apparent after only 4 weeks of treatment. To develop a prediction rule to identify patients unlikely to respond adequately to methotrexate. Patient-level data from CHAMPION (NCT00235820, N = 110) was used to construct a prediction model for week 16 PASI75 by using patient baseline characteristics and week 4 PASI25. A prediction rule was determined on the basis of the sensitivity and specificity and validated in terms of week 16 PASI75 response in an independent validation sample from trial M10-255 (NCT00679731, N = 163). PASI25 achievement at week 4 (odds ratio = 8.917) was highly predictive of response with methotrexate at week 16. Patients with a predicted response probability <30% were recommended to discontinue methotrexate. The rates of week 16 PASI75 response were 65.8% and 21.1% (P < .001) for patients recommended to continue and discontinue methotrexate, respectively. The CHAMPION trial excluded patients previously treated with biologics, and the M10-255 trial had no restrictions. A prediction rule was developed and validated to identify patients unlikely to respond adequately to methotrexate. The rule indicates that 4 weeks of methotrexate might be sufficient to predict long-term response with limited safety risk. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.
Trial endpoints for drug approval in oncology: Chemoprevention.
Beitz, J
2001-04-01
As with other drugs, new drug applications for marketing approval of chemopreventive drugs must include data from adequate and well-controlled clinical trials that demonstrate effectiveness and safety for the intended use. This article summarizes the regulatory requirements for traditional marketing approval, as well as for approval under the accelerated approval regulations. Unlike traditional approval, accelerated approval is based on a surrogate endpoint that is reasonably likely to predict clinical benefit. Discussions with the Food and Drug Administration (FDA) regarding the validity of trial endpoints that may serve as surrogates for clinical benefit for accelerated approval should take place as early as possible in drug development. Meetings with the FDA to discuss these issues may be requested throughout the clinical development of a new drug.
Renal Denervation: a Field in Flux.
Laffin, Luke J; Bakris, George L
2016-07-01
SYMPLICITY HTN-3 was a pivotal moment for renal denervation as a treatment option for resistant hypertension. Prior unblinded studies were called into question given the negative results of the first sham-controlled trial of renal denervation. Reevaluation of the renal denervation procedure demonstrated that a more precise approach was needed to adequately denervate the kidney. This new approach has been implemented in two ongoing clinical trials, one on and one off medications to assess the new procedure's efficacy and safety. These and other ongoing trials will be discussed in the context of older studies in this field. We focus on novel findings published following the release of SYMPLICITY HTN-3 data in early 2014 and look to the future of renal denervation in the treatment of primary hypertension.
Compensation of research-related injuries in the European Union.
Avilds, Miguelangel Ramiro
2014-12-01
The planned reform of the Clinical Trials Directive has re-opened the debate over how to implement and interpret research-related injuries regulation. In the European Union (EU), clinical trials are currently regulated by Directive 2001/20/EC, which establishes the provision of mandatory insurance before clinical trials commence but is silent on the system of liability. The proposed new Regulation will impact biomedical research assurance in all EU Member States because it points to insurance costs as being one of the causes of the fall in the number of clinical trials carried out in the EU. Despite the adoption of a risk-balance approach, the proposed new Regulation does not include a no-fault compensation system to protect subjects participating in clinical trials. An adequate protection of the rights and wellbeing of trial subjects would require not only mandatory insurance for clinical trials but also a no-fault compensation system. The new regulation should include a general clause requiring mandatory insurance and establishing liability insurance based on no-fault compensation; an exception clause, enabling the performance of clinical trials without insurance in the case of low-risk interventions or non-commercial clinical trials; and an exclusion clause, excluding compensation when there is no causal connection between injuries and clinical trial.
Lower skin temperature decreases maximal cycling performance.
Imai, Daiki; Okazaki, Kazunobu; Matsumura, Shinya; Suzuki, Takashi; Miyazawa, Taiki; Suzuki, Akina; Takeda, Ryosuke; Hamamoto, Takeshi; Zako, Tetsuo; Kawabata, Takashi; Miyagawa, Toshiaki
2011-12-01
It is known that external cooling of body regions involved in exercise, prior to exercise, decreases anaerobic performance. However, there have been no studies reporting the effects of whole body skin surface cooling before exercise on maximal anaerobic capacity. In order to clarify the effects, we compared power output during the Wingate anaerobic test between preconditioning by exposure to temperature 10 degrees C and 25 degrees C. Eight healthy males carried out the Wingate test for 30 seconds, after pre-conditioning for 60 minutes using a perfusion suit with water at a temperature of 10 degrees C or 25 degrees C. We evaluated the peak power (PP) and peak power slope (PS) of the power output. Mean skin temperature (T(sk)) at 60 minutes of pre-conditioning in the 10 degrees C trial was significantly lower than in the 25 degrees C trial (p < 0.05). PP and also PS were significantly lower in the 10 degrees C trial than in the 25 degrees C trial. Changes (Δ) in PP between the 10 degrees C trial and the 25 degrees C trial were strongly correlated with ΔT(sk) and Δ in thigh and leg skin temperature (ΔT(thigh) and ΔT(leg), respectively), whereas ΔPS was strongly correlated with ΔT(sk), but not with ΔT(thigh) and ΔT(leg). Whole body skin surface cooling prior to exercise restricts anaerobic capacity, especially in the initial phase of exercise.
Autologous blood preparations rich in platelets, fibrin and growth factors.
Fioravanti, C; Frustaci, I; Armellin, E; Condò, R; Arcuri, C; Cerroni, L
2015-01-01
Bone regeneration is often needed prior to dental implant treatment due to the lack of adequate quantity and quality after infectious diseases. The greatest regenerative power was obtained with autologous tissue, primarily the bone alive, taken from the same site or adjacent sites, up to the use centrifugation of blood with the selection of the parts with the greatest potential regenerative. In fact, various techniques and technologies were chronologically successive to cope with an ever better preparation of these concentrates of blood. Our aim is to review these advances and discuss the ways in which platelet concentrates may provide such unexpected beneficial therapeutic effects. The research has been carried out in the MEDLINE and Cochrane Central Register of Controlled Trials database by choosing keywords as "platelet rich plasma", "platelet rich fibrin", "platelet growth factors", and "bone regeneration" and "dentistry". Autologous platelet rich plasma is a safe and low cost procedure to deliver growth factors for bone and soft tissue healing. The great heterogeneity of clinical outcomes can be explained by the different PRP products with qualitative and quantitative difference among substance.
Faith-Based Institutions as Venues for Obesity Prevention.
Maynard, Maria J
2017-06-01
The aim of this current narrative review is to critique the scope and value of recent studies with a focus on obesity-related health promotion in faith organizations. Electronic database searches, scanning of the reference lists of identified articles, and hand searching of journals for articles written in English and published in 2013-2016 revealed 16 studies. Half of the studies involved African-Americans, in churches and with predominantly female participants. Research among other ethnic groups was more likely to be exploratory. All of the 11 studies reporting the impact of programmes on weight-related measures showed favourable outcomes. However, due to study limitations (small sample size, short duration, attrition), significant unbiased effects cannot yet be concluded for most of the interventions reviewed. Study strengths included application of theory in community engagement and detailed description of cultural tailoring. Faith organizations show promise as settings for obesity prevention among high-risk groups, particularly African-Americans. Support for progressing formative work to adequately powered, randomized controlled trials is vital. Wider involvement of diverse faith settings and targeting obesity in men and childhood would be valuable developments.
Taxonomy for complexity theory in the context of maternity care.
Nieuwenhuijze, Marianne; Downe, Soo; Gottfreðsdóttir, Helga; Rijnders, Marlies; du Preez, Antoinette; Vaz Rebelo, Piedade
2015-09-01
The linear focus of 'normal science' is unable to adequately take account of the complex interactions that direct health care systems. There is a turn towards complexity theory as a more appropriate framework for understanding system behaviour. However, a comprehensive taxonomy for complexity theory in the context of health care is lacking. This paper aims to build a taxonomy based on the key complexity theory components that have been used in publications on complexity theory and health care, and to explore their explanatory power for health care system behaviour, specifically for maternity care. A search strategy was devised in PubMed and 31 papers were identified as relevant for the taxonomy. The final taxonomy for complexity theory included and defined 11 components. The use of waterbirth and the impact of the Term Breech trial showed that each of the components of our taxonomy has utility in helping to understand how these techniques became widely adopted. It is not just the components themselves that characterise a complex system but also the dynamics between them. Copyright © 2015 Elsevier Ltd. All rights reserved.
Parodi, A; Drago, F; Paolino, S; Cozzani, E; Gallo, R
2011-11-01
A range of treatment options are available in rosacea, which include several topical (mainly metronidazole, azelaic acid, other antibiotics, sulfur, retinoids) and oral drugs (mainly tetracyclines, metronidazole, macrolides). In some cases, the first choice is a systemic therapy because patients may have sensitive skin and topical medications can be irritant. Isotretinoin can be used in resistant cases of rosacea. Unfortunately, the majority of studies on rosacea treatments are at high or unclear risk of bias. A recent Cochrane review found that only topical metronidazole, azelaic acid, and oral doxycycline (40 mg) had some evidence to support their effectiveness in moderate to severe rosacea and concluded that further well-designed, adequately-powered randomised controlled trials are required. In our practice, we evaluate our patients for the presence of two possible triggers, Helicobacter pylori infection and small intestinal bacterial overgrowth. When they are present we use adapted antibiotic protocols. If not, we use oral metronidazole or oral tetracycline to treat papulopustolar rosacea. We also look for Demodex folliculorum infestation. When Demodex concentration is higher than 5/cm(2) we use topical crotamiton 10% or metronidazole. Copyright © 2011 Elsevier Masson SAS. All rights reserved.
Parodi, A; Drago, F; Paolino, S; Cozzani, E; Gallo, R
2011-09-01
A range of treatment options are available in rosacea, which include several topical (mainly metronidazole, azelaic acid, other antibiotics, sulfur, retinoids) and oral drugs (mainly tetracyclines, metronidazole, macrolides). In some cases, the first choice is a systemic therapy because patients may have sensitive skin and topical medications can be irritant. Isotretinoin can be used in resistant cases of rosacea. Unfortunately, the majority of studies on rosacea treatments are at high or unclear risk of bias. A recent Cochrane review found that only topical metronidazole, azelaic acid, and oral doxycycline (40 mg) had some evidence to support their effectiveness in moderate to severe rosacea and concluded that further well-designed, adequately-powered randomised controlled trials are required. In our practice, we evaluate our patients for the presence of two possible triggers, Helicobacter pylori infection and small intestinal bacterial overgrowth. When they are present we use adapted antibiotic protocols. If not, we use oral metronidazole or oral tetracycline to treat papulopustolar rosacea. We also look for Demodex folliculorum infestation. When Demodex concentration is higher than 5/cm(2) we use topical crotamiton 10% or metronidazole. Copyright © 2011 Elsevier Masson SAS. All rights reserved.
Pharmacotherapy for thyroid nodules. A systematic review and meta-analysis.
Richter, Bernd; Neises, Gudrun; Clar, Christine
2002-09-01
The review highlights the uncertainty in the management of nodular thyroid disease. Thyroxine suppressive treatment is given in the hope that nodules might decrease in size, sometimes assuming that dependency on TSH is different in benign and malignant nodular disease. Follow-up of benign nodules over 10 years suggested that most remain the same, shrink, or disappear [14]. TSH suppression may lead to hyperthyroidism, reduced bone density [37.39], and atrial fibrilation; however, apart from reduction of nodule size or arrest in nodule growth, thyroxine therapy may benefit patients by reducing perinodular volume. Consequently, both pressure symptoms and cosmetic complaints could improve. Unfortunately, no information concerning symptoms or well-being is available from published randomized trials. In conclusion, more high quality studies of sufficient duration with adequate power estimation are needed. Uncertainty about predictors of response or the impact on outcomes that are important to patients leaves considerable doubt about the wisdom of applying suppressive therapy. Future studies shoudl include patient-important outcomes including thyroid cancer incidence, health-related quality of life and costs.
Ilie, Cristian P; Mischianu, Dan L; Pemberton, Richard J
2007-06-01
We reviewed previous publications on post-orgasmic pain with reference to prevalence, epidemiology and treatment options, using the Ovid and PubMed (updated May 2006) databases to comprehensively search MEDLINE for reports on post-orgasmic pain that included peer-reviewed English-language articles. Official proceedings of internationally known scientific societies were also assessed. Because of the heterogeneity of the studies we did not apply meta- analytic techniques to the data. The incidence of post-orgasmic pain is 1-9.7%. The ejaculatory pain is associated with prostatitis, chronic pelvic pain syndrome, benign prostatic hyperplasia, and ejaculatory duct obstruction; it is also described in patients after procedures like radical prostatectomy. Aetiopathogenic theories include those referring to bladder neck closure and pudendal neuropathy. The treatment options vary from self-care, a 'perineal hyperprotection programme' to medication with the alpha-blocker, topiramate, and even surgical procedures like removing a section of the sacrotuberous ligament, neurolysis of the pudendal nerve or removing a section of the sacrospinous ligament. This is the first update of the subject, with reference to prevalence, epidemiology and treatment options. There is a need for adequately powered, prospective randomized trials on aetiology and treatment options.
Veronese, Nicola; Facchini, Silvia; Stubbs, Brendon; Luchini, Claudio; Solmi, Marco; Manzato, Enzo; Sergi, Giuseppe; Maggi, Stefania; Cosco, Theodore; Fontana, Luigi
2017-01-01
Whilst obesity is associated with a higher risk of cognitive impairment, the influence of weight loss on cognitive function in obese/overweight people is equivocal. We conducted a meta-analysis of randomized controlled trials (RCTs) and longitudinal studies evaluating the influence of voluntary weight loss on cognitive function in obese/overweight individuals. Articles were acquired from a systematic search of major databases from inception till 01/2016. A random effect meta-analysis of weight loss interventions (diet, physical activity, bariatric surgery) on different cognitive domains (memory, attention, executive functions, language and motor speed) was conducted. Twenty studies (13 longitudinal studies=551 participants; 7 RCTs=328 treated vs. 140 controls) were included. Weight loss was associated with a significant improvement in attention and memory in both longitudinal studies and RCTs, whereas executive function and language improved in longitudinal and RCT studies, respectively. In conclusion, intentional weight loss in obese/overweight people is associated with improvements in performance across various cognitive domains. Future adequately powered RCTs are required to confirm/refute these findings. Copyright © 2016 Elsevier Ltd. All rights reserved.
Hoare, Jacqueline; Carey, Paul; Joska, John A; Carrara, Henri; Sorsdahl, Katherine; Stein, Dan J
2014-02-01
Depression can be a chronic and impairing illness in people with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome. Large randomized studies of newer selective serotonin reuptake inhibitors such as escitalopram in the treatment of depression in HIV, examining comparative treatment efficacy and safety, have yet to be done in HIV-positive patients. This was a fixed-dose, placebo-controlled, randomized, double-blind study to investigate the efficacy of escitalopram in HIV-seropositive subjects with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, major depressive disorder. One hundred two participants were randomly assigned to either 10 mg of escitalopram or placebo for 6 weeks. An analysis of covariance of the completers found that there was no advantage for escitalopram over placebo on the Montgomery-Asberg Depression Rating Scale (p = 0.93). Sixty-two percent responded to escitalopram and 59% responded to placebo on the Clinical Global Impression Scale. Given the relatively high placebo response, future trials in this area need to be selective in participant recruitment and to be adequately powered.
Flanagan, Julianne C; Sippel, Lauren M; Wahlquist, Amy; Moran-Santa Maria, Megan M; Back, Sudie E
2018-03-01
Posttraumatic stress disorder (PTSD) is a chronic, debilitating condition for which Prolonged Exposure (PE) therapy is highly efficacious. However, for some individuals, premature dropout and residual PTSD symptoms remain obstacles. The neuropeptide oxytocin is a promising candidate to enhance PE due to its ability to enhance 1) prosocial cognition and behavior, which are theorized to promote positive working alliance, and 2) extinction learning, which is the central mechanism of action underlying successful PE treatment. Despite a robust theoretical rationale, no studies to date have combined evidence-based psychotherapy for PTSD with oxytocin. This randomized, placebo-controlled, double-blind pilot trial examined the feasibility, safety, and preliminary efficacy of augmenting PE with oxytocin. Participants were 17 individuals with diverse index traumas. Participants self-administered intranasal oxytocin (40 IU) or matching placebo 45 min prior to each weekly PE therapy session. One adverse event occurred in the placebo group and three individuals dropped out (17.6%; 2 oxytocin group and 1 placebo group). The oxytocin group demonstrated lower PTSD and depression symptoms during PE, and had higher working alliance scores, although these differences did not reach statistical significance. Although preliminary, the findings support the feasibility of oxytocin combined with PE. Adequately powered studies are necessary to determine whether oxytocin enhances PE treatment outcomes and to examine potential mechanisms, such as accelerating extinction learning, enhancing early response, and preventing premature dropout. NCT03238924. Copyright © 2017. Published by Elsevier Ltd.
Genomic markers for decision making: what is preventing us from using markers?
Coyle, Vicky M; Johnston, Patrick G
2010-02-01
The advent of novel genomic technologies that enable the evaluation of genomic alterations on a genome-wide scale has significantly altered the field of genomic marker research in solid tumors. Researchers have moved away from the traditional model of identifying a particular genomic alteration and evaluating the association between this finding and a clinical outcome measure to a new approach involving the identification and measurement of multiple genomic markers simultaneously within clinical studies. This in turn has presented additional challenges in considering the use of genomic markers in oncology, such as clinical study design, reproducibility and interpretation and reporting of results. This Review will explore these challenges, focusing on microarray-based gene-expression profiling, and highlights some common failings in study design that have impacted on the use of putative genomic markers in the clinic. Despite these rapid technological advances there is still a paucity of genomic markers in routine clinical use at present. A rational and focused approach to the evaluation and validation of genomic markers is needed, whereby analytically validated markers are investigated in clinical studies that are adequately powered and have pre-defined patient populations and study endpoints. Furthermore, novel adaptive clinical trial designs, incorporating putative genomic markers into prospective clinical trials, will enable the evaluation of these markers in a rigorous and timely fashion. Such approaches have the potential to facilitate the implementation of such markers into routine clinical practice and consequently enable the rational and tailored use of cancer therapies for individual patients.
Oberman, Lindsay M.; Enticott, Peter G.; Casanova, Manuel F.; Rotenberg, Alexander; Pascual-Leone, Alvaro; McCracken, James T.
2016-01-01
Autism Spectrum Disorder (ASD) is a behaviorally defined complex neurodevelopmental syndrome characterized by impairments in social communication, by the presence of restricted and repetitive behaviors, interests and activities, and by abnormalities in sensory reactivity. Transcranial magnetic stimulation (TMS) is a promising, emerging tool for the study and potential treatment of ASD. Recent studies suggest that TMS measures provide rapid and noninvasive pathophysiological ASD biomarkers. Furthermore, repetitive TMS (rTMS) may represent a novel treatment strategy for reducing some of the core and associated ASD symptoms. However, the available literature on the TMS use in ASD is preliminary, composed of studies with methodological limitations. Thus, off-label clinical rTMS use for therapeutic interventions in ASD without an investigational device exemption and outside of an IRB approved research trial is premature pending further, adequately powered and controlled trials. Leaders in this field have gathered annually for a two-day conference (prior to the 2014 and 2015 International Meeting for Autism Research, IMFAR) to share recent progress, promote collaboration across laboratories, and establish consensus on protocols. Here we review the literature in the use of TMS in ASD in the context of the unique challenges required for the study and exploration of treatment strategies in this population. We also suggest future directions for this field of investigations. While its true potential in ASD has yet to be delineated, TMS represents an innovative research tool and a novel, possibly transformative approach to the treatment of neurodevelopmental disorders. PMID:26536383
Evidence-based pharmacotherapy of post-traumatic stress disorder (PTSD).
Ipser, Jonathan C; Stein, Dan J
2012-07-01
Post-traumatic stress disorder (PTSD) is a prevalent and disabling disorder. Recognition of neurobiological abnormalities associated with this condition suggests the potential efficacy of medication in its treatment. Nevertheless, questions regarding the efficacy of medications remain, despite general endorsement by clinical practice guidelines of selective serotonin reuptake inhibitors (SSRIs) as first-line agents in treating PTSD. This paper reviews evidence from randomized controlled trials (RCTs) for the efficacy of acute and long-term pharmacotherapy for PTSD, including the treatment of refractory PTSD. In addition, we conducted a systematic meta-analysis to compare the efficacy of different medications in treating PTSD. The effects of methodological study features (including year of publication, duration, number of centres) and sample characteristics (proportion of combat veterans, gender composition) were also tested. The largest body of evidence for short- and long-term efficacy of medication currently exists for SSRIs, with promising initial findings for the selective noradrenergic reuptake inhibitor venlafaxine and the atypical antipsychotic risperidone. Treatment effect was predicted by number of centres and recency of the study, with little evidence that sample characteristics predicted response. Evidence for the effectiveness of benzodiazepines is lacking, despite their continued use in clinical practice. Finally, the α1 antagonist prazosin and the atypical antipsychotics show some efficacy in treatment-resistant PTSD. Adequately powered trials that are designed in accordance with best-practice guidelines are required to provide conclusive evidence of clinically relevant differences in efficacy between agents in treating PTSD, and to help estimate clinical and methodological predictors of treatment response.
The spatiotemporal MEG covariance matrix modeled as a sum of Kronecker products.
Bijma, Fetsje; de Munck, Jan C; Heethaar, Rob M
2005-08-15
The single Kronecker product (KP) model for the spatiotemporal covariance of MEG residuals is extended to a sum of Kronecker products. This sum of KP is estimated such that it approximates the spatiotemporal sample covariance best in matrix norm. Contrary to the single KP, this extension allows for describing multiple, independent phenomena in the ongoing background activity. Whereas the single KP model can be interpreted by assuming that background activity is generated by randomly distributed dipoles with certain spatial and temporal characteristics, the sum model can be physiologically interpreted by assuming a composite of such processes. Taking enough terms into account, the spatiotemporal sample covariance matrix can be described exactly by this extended model. In the estimation of the sum of KP model, it appears that the sum of the first 2 KP describes between 67% and 93%. Moreover, these first two terms describe two physiological processes in the background activity: focal, frequency-specific alpha activity, and more widespread non-frequency-specific activity. Furthermore, temporal nonstationarities due to trial-to-trial variations are not clearly visible in the first two terms, and, hence, play only a minor role in the sample covariance matrix in terms of matrix power. Considering the dipole localization, the single KP model appears to describe around 80% of the noise and seems therefore adequate. The emphasis of further improvement of localization accuracy should be on improving the source model rather than the covariance model.
Newton, Robert L; Johnson, William D; Hendrick, Chelsea; Harris, Melissa; Andrews, Emanuel; Johannsen, Neil; Rodarte, Ruben Q; Hsia, Daniel S; Church, Timothy S
2015-07-01
Lack of regular physical activity at prescribed intensity levels is a modifiable risk factor for insulin resistance and the development of diabetes. African American men are at increased risk for developing diabetes and most African American men are not meeting the current recommended levels of physical activity. The primary objective of the Aerobic Plus Resistance Training and Insulin Resistance in African American Men (ARTIIS) study is to determine the effectiveness of an exercise training intervention aimed at reducing diabetes risk factors in African American men at risk for developing diabetes. Insufficiently active 35-70 year old African American men with a family history of diabetes were eligible for the study. The 5-month randomized controlled trial assigns 116 men to an exercise training or healthy living control arm. The exercise training arm combines aerobic and resistance training according to the current national physical activity recommendations and is conducted in community (YMCA) facilities. The healthy living arm receives information promoting healthy lifestyle changes. Insulin response to an oral glucose load is the primary outcome measure, and changes in physiological parameters, cardiorespiratory fitness, strength, body composition, and psychological well-being comprise the secondary outcomes. The ARTIIS study is one of the first adequately powered, rigorously designed studies to investigate the effects of an aerobic plus resistance exercise training program and to assess adherence to exercise training in community facilities, in African American men. Copyright © 2015 Elsevier Inc. All rights reserved.
Systematic review of use of β-blockers in sepsis.
Chacko, Cyril Jacob; Gopal, Shameer
2015-01-01
We proposed a review of present literature and systematic analysis of present literature to summarize the evidence on the use of β-blockers on the outcome of a patient with severe sepsis and septic shock. Medline, EMBASE, Cochrane Library were searched from 1946 to December 2013. The bibliography of all relevant articles was hand searched. Full-text search of the grey literature was done through the medical institution database. The database search identified a total of 1241 possible studies. The citation list was hand searched by both the authors. A total of 9 studies were identified. Most studies found a benefit from β-blocker administration in sepsis. This included improved heart rate (HR) control, decreased mortality and improvement in acid-base parameters. Chronic β-blocker usage in sepsis was also associated with improved mortality. The administration of β-blockers during sepsis was associated with better control of HR. The methodological quality of all the included studies, however, was poor. There is insufficient evidence to justify the routine use of β-blockers in sepsis. A large adequately powered multi-centered randomized controlled clinical trial is required to address the question on the efficacy of β-blocker usage in sepsis. This trial should also consider a number of important questions including the choice of β-blocker used, optimal dosing, timing of intervention, duration of intervention and discontinuation of the drug. Until such time based on the available evidence, there is no place for the use of β-blockers in sepsis in current clinical practice.
2014-01-01
Background The DerSimonian and Laird approach (DL) is widely used for random effects meta-analysis, but this often results in inappropriate type I error rates. The method described by Hartung, Knapp, Sidik and Jonkman (HKSJ) is known to perform better when trials of similar size are combined. However evidence in realistic situations, where one trial might be much larger than the other trials, is lacking. We aimed to evaluate the relative performance of the DL and HKSJ methods when studies of different sizes are combined and to develop a simple method to convert DL results to HKSJ results. Methods We evaluated the performance of the HKSJ versus DL approach in simulated meta-analyses of 2–20 trials with varying sample sizes and between-study heterogeneity, and allowing trials to have various sizes, e.g. 25% of the trials being 10-times larger than the smaller trials. We also compared the number of “positive” (statistically significant at p < 0.05) findings using empirical data of recent meta-analyses with > = 3 studies of interventions from the Cochrane Database of Systematic Reviews. Results The simulations showed that the HKSJ method consistently resulted in more adequate error rates than the DL method. When the significance level was 5%, the HKSJ error rates at most doubled, whereas for DL they could be over 30%. DL, and, far less so, HKSJ had more inflated error rates when the combined studies had unequal sizes and between-study heterogeneity. The empirical data from 689 meta-analyses showed that 25.1% of the significant findings for the DL method were non-significant with the HKSJ method. DL results can be easily converted into HKSJ results. Conclusions Our simulations showed that the HKSJ method consistently results in more adequate error rates than the DL method, especially when the number of studies is small, and can easily be applied routinely in meta-analyses. Even with the HKSJ method, extra caution is needed when there are = <5 studies of very unequal sizes. PMID:24548571
Wittenberg, Marc André; Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim
2018-04-01
Neuronal oscillations are a ubiquitous phenomenon in the human nervous system. Alpha-band oscillations (8-12 Hz) have been shown to correlate negatively with attention and performance, whereas gamma-band oscillations (40-150 Hz) correlate positively. Here, we studied the relation between prestimulus alpha-band power and poststimulus gamma-band power in a suprathreshold tactile discrimination task. Participants received two electrical stimuli to their left index finger with different SOAs (0 msec, 100 msec, intermediate SOA, intermediate SOA ± 10 msec). The intermediate SOA was individually determined so that stimulation was bistable, and participants perceived one stimulus in half of the trials and two stimuli in the other half. We measured neuronal activity with magnetoencephalography (MEG). In trials with intermediate SOAs, behavioral performance correlated inversely with prestimulus alpha-band power but did not correlate with poststimulus gamma-band power. Poststimulus gamma-band power was high in trials with low and high prestimulus alpha-band power and low for intermediate prestimulus alpha-band power (i.e., U-shaped). We suggest that prestimulus alpha activity modulates poststimulus gamma activity and subsequent perception: (1) low prestimulus alpha-band power leads to high poststimulus gamma-band power, biasing perception such that two stimuli were perceived; (2) intermediate prestimulus alpha-band power leads to low gamma-band power (interpreted as inefficient stimulus processing), consequently, perception was not biased in either direction; and (3) high prestimulus alpha-band power leads to high poststimulus gamma-band power, biasing perception such that only one stimulus was perceived.
The Cost of Freedom: Speech in the Courtroom.
ERIC Educational Resources Information Center
Brownlee, Don; Brownlee, Suzan
The political trials of the past two decades have shown the misuse and abuse of judicial summary contempt power in limiting individual liberty. The primary justification offered for use of the contempt power has been the need to deter obstruction of the administration of justice. The trials of the Chicago 7 and the Black Panthers were intricately…
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
Thompson, Carl
2004-01-01
Many of the interventions that nurses develop and implement are in themselves complex and have to operate in situations of irreducible complexity and uncertainty. This article argues that the primary means of generating knowledge for the evidence-based deployment of complex interventions should be the pragmatic randomised controlled trial. Randomised controlled trials represent the only research design to adequately deal with that which we know and (far more importantly) that which we do not. Using the example of practice development as an exemplar for complexity, and drawing on the objections often voiced as a response to calls to make use of randomised controlled trials in nursing and nursing research, the article presents a developmental framework and some methodological solutions to problems often encountered. Randomised controlled trials, whilst undoubtedly methodologically and strategically challenging, offer the most robust basis for developing primary research knowledge on the effects of complex interventions in nursing and their active components.
Substance Use and the Treatment of Resistant Depression in Adolescents
ERIC Educational Resources Information Center
Goldstein, Benjamin I.; Shamseddeen, Wael; Spirito, Anthony; Emslie, Graham; Clarke, Greg; Wagner, Karen Dineen; Asarnow, Joan Rosenbaum; Vitiello, Benedetto; Ryan, Neal; Birmaher, Boris; Mayes, Taryn; Onorato, Matthew; Zelazny, Jamie; Brent, David A.
2009-01-01
Objective: Despite the known association between substance use disorders and major depressive disorder (MDD) among adolescents, little is known regarding substance use among adolescents with MDD. Method: Youths with MDD who had not improved after an adequate selective serotonin reuptake inhibitor trial (N = 334) were enrolled in the Treatment of…
ERIC Educational Resources Information Center
Jordans, Mark J. D.; Komproe, Ivan H.; Tol, Wietse A.; Kohrt, Brandon A.; Luitel, Nagendra P.; Macy, Robert D.; de Jong, Joop T. V. M.
2010-01-01
Background: In situations of ongoing violence, childhood psychosocial and mental health problems require care. However, resources and evidence for adequate interventions are scarce for children in low- and middle-income countries. This study evaluated a school-based psychosocial intervention in conflict-affected, rural Nepal. Methods: A cluster…
Anesthetic Efficacy of Meperidine in Teeth With Symptomatic Irreversible Pulpitis
Mohajeri, Ladan; Salehi, Farnaz; Mehrvarzfar, Payman; Arfaee, Hamide; Bohluli, Behnam; Hamedy, Reza
2015-01-01
Achieving adequate pulpal anesthesia in mandibular teeth is always a challenge. Supplementary injections and using drugs in combination are some methods implemented to overcome this hurdle. In this randomized clinical trial, use of meperidine in conjunction with lidocaine in intraligamentary injection did not exhibit significant improvement in anesthesia. PMID:25849469
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-28
.... The guidance provides recommendations on when and how genomic principles should be considered and... recommendations on when and how genomic principles should be considered and applied in early-phase clinical... the larger, later adequate, and well-controlled trials (phase 3) that are needed to support marketing...