Sample records for adequately powered trial

  1. Kidney function endpoints in kidney transplant trials: a struggle for power.

    PubMed

    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.

  2. Linear Combinations of Multiple Outcome Measures to Improve the Power of Efficacy Analysis ---Application to Clinical Trials on Early Stage Alzheimer Disease

    PubMed Central

    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

  3. 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…

  4. Enrichment methods provide a feasible approach to comprehensive and adequately powered investigations of the brain methylome

    PubMed Central

    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

  5. Revisiting sample size: are big trials the answer?

    PubMed

    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.

  6. Publication bias was not a good reason to discourage trials with low power.

    PubMed

    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.

  7. Design, analysis and presentation of factorial randomised controlled trials

    PubMed Central

    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

  8. The Power of Low Back Pain Trials: A Systematic Review of Power, Sample Size, and Reporting of Sample Size Calculations Over Time, in Trials Published Between 1980 and 2012.

    PubMed

    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.

  9. Independent but Coordinated Trials: Insights from the Practice Based Opportunities for Weight Reduction (POWER) Trials Collaborative Research Group

    PubMed Central

    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

  10. Estimating statistical power for open-enrollment group treatment trials.

    PubMed

    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.

  11. [An investigation of the statistical power of the effect size in randomized controlled trials for the treatment of patients with type 2 diabetes mellitus using Chinese medicine].

    PubMed

    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

  12. A generalized concept of power helped to choose optimal endpoints in clinical trials.

    PubMed

    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.

  13. Clinical trial design for orthodontists.

    PubMed

    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.

  14. Statistical power, the Belmont report, and the ethics of clinical trials.

    PubMed

    Vollmer, Sara H; Howard, George

    2010-12-01

    Achieving a good clinical trial design increases the likelihood that a trial will take place as planned, including that data will be obtained from a sufficient number of participants, and the total number of participants will be the minimal required to gain the knowledge sought. A good trial design also increases the likelihood that the knowledge sought by the experiment will be forthcoming. Achieving such a design is more than good sense-it is ethically required in experiments when participants are at risk of harm. This paper argues that doing a power analysis effectively contributes to ensuring that a trial design is good. The ethical importance of good trial design has long been recognized for trials in which there is risk of serious harm to participants. However, whether the quality of a trial design, when the risk to participants is only minimal, is an ethical issue is rarely discussed. This paper argues that even in cases when the risk is minimal, the quality of the trial design is an ethical issue, and that this is reflected in the emphasis the Belmont Report places on the importance of the benefit of knowledge gained by society. The paper also argues that good trial design is required for true informed consent.

  15. Efficacy of S-flurbiprofen plaster in knee osteoarthritis treatment: Results from a phase III, randomized, active-controlled, adequate, and well-controlled trial.

    PubMed

    Yataba, Ikuko; Otsuka, Noboru; Matsushita, Isao; Matsumoto, Hideo; Hoshino, Yuichi

    2017-01-01

    S-flurbiprofen plaster (SFPP) is a novel non-steroidal anti-inflammatory drug (NSAID) patch, intended for topical treatment for musculoskeletal diseases. This trial was conducted to examine the effectiveness of SFPP using active comparator, flurbiprofen (FP) patch, on knee osteoarthritis (OA) symptoms. This was a phase III, multi-center, randomized, adequate, and well-controlled trial, both investigators and patients were blinded to the assigned treatment. Enrolled 633 knee OA patients were treated with either SFPP or FP patch for two weeks. The primary endpoint was improvement in knee pain on rising from the chair as assessed by visual analogue scale (rVAS). Safety was evaluated through adverse events (AEs). The change in rVAS was 40.9 mm in SFPP group and 30.6 mm in FP patch group (p < 0.001). The incidence of drug-related AEs at the application site was 9.5% (32 AEs, 29 mild and 3 moderate) in SFPP and 1.6% in FP patch (p < 0.001). Withdrawals due to AE were five in SFPP and one in FP patch. The superiority of SFPP in efficacy was demonstrated. Most of AEs were mild and few AEs led to treatment discontinuation. Therefore, SFPP provides an additional option for knee OA therapy.

  16. Power analysis to detect treatment effects in longitudinal clinical trials for Alzheimer's disease.

    PubMed

    Huang, Zhiyue; Muniz-Terrera, Graciela; Tom, Brian D M

    2017-09-01

    Assessing cognitive and functional changes at the early stage of Alzheimer's disease (AD) and detecting treatment effects in clinical trials for early AD are challenging. Under the assumption that transformed versions of the Mini-Mental State Examination, the Clinical Dementia Rating Scale-Sum of Boxes, and the Alzheimer's Disease Assessment Scale-Cognitive Subscale tests'/components' scores are from a multivariate linear mixed-effects model, we calculated the sample sizes required to detect treatment effects on the annual rates of change in these three components in clinical trials for participants with mild cognitive impairment. Our results suggest that a large number of participants would be required to detect a clinically meaningful treatment effect in a population with preclinical or prodromal Alzheimer's disease. We found that the transformed Mini-Mental State Examination is more sensitive for detecting treatment effects in early AD than the transformed Clinical Dementia Rating Scale-Sum of Boxes and Alzheimer's Disease Assessment Scale-Cognitive Subscale. The use of optimal weights to construct powerful test statistics or sensitive composite scores/endpoints can reduce the required sample sizes needed for clinical trials. Consideration of the multivariate/joint distribution of components' scores rather than the distribution of a single composite score when designing clinical trials can lead to an increase in power and reduced sample sizes for detecting treatment effects in clinical trials for early AD.

  17. The LIPPSMAck POP (Lung Infection Prevention Post Surgery - Major Abdominal - with Pre-Operative Physiotherapy) trial: study protocol for a multi-centre randomised controlled trial.

    PubMed

    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

  18. [Adequate application of quantitative and qualitative statistic analytic methods in acupuncture clinical trials].

    PubMed

    Tan, Ming T; Liu, Jian-ping; Lao, Lixing

    2012-08-01

    Recently, proper use of the statistical methods in traditional Chinese medicine (TCM) randomized controlled trials (RCTs) has received increased attention. Statistical inference based on hypothesis testing is the foundation of clinical trials and evidence-based medicine. In this article, the authors described the methodological differences between literature published in Chinese and Western journals in the design and analysis of acupuncture RCTs and the application of basic statistical principles. In China, qualitative analysis method has been widely used in acupuncture and TCM clinical trials, while the between-group quantitative analysis methods on clinical symptom scores are commonly used in the West. The evidence for and against these analytical differences were discussed based on the data of RCTs assessing acupuncture for pain relief. The authors concluded that although both methods have their unique advantages, quantitative analysis should be used as the primary analysis while qualitative analysis can be a secondary criterion for analysis. The purpose of this paper is to inspire further discussion of such special issues in clinical research design and thus contribute to the increased scientific rigor of TCM research.

  19. A study of sertraline in dialysis (ASSertID): a protocol for a pilot randomised controlled trial of drug treatment for depression in patients undergoing haemodialysis.

    PubMed

    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

  20. Traditional and new composite endpoints in heart failure clinical trials: facilitating comprehensive efficacy assessments and improving trial efficiency.

    PubMed

    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.

  1. Clinical trials bureaucracy: unintended consequences of well-intentioned policy.

    PubMed

    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.

  2. Methodological reporting of randomized clinical trials in respiratory research in 2010.

    PubMed

    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.

  3. Quality of radiotherapy reporting in randomized controlled trials of prostate cancer.

    PubMed

    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.

  4. Adverse prognostic value of peritumoral vascular invasion: is it abrogated by adequate endocrine adjuvant therapy? Results from two International Breast Cancer Study Group randomized trials of chemoendocrine adjuvant therapy for early breast cancer

    PubMed Central

    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

  5. Power/Sample Size Calculations for Assessing Correlates of Risk in Clinical Efficacy Trials

    PubMed Central

    Gilbert, Peter B.; Janes, Holly E.; Huang, Yunda

    2016-01-01

    In a randomized controlled clinical trial that assesses treatment efficacy, a common objective is to assess the association of a measured biomarker response endpoint with the primary study endpoint in the active treatment group, using a case-cohort, case-control, or two-phase sampling design. Methods for power and sample size calculations for such biomarker association analyses typically do not account for the level of treatment efficacy, precluding interpretation of the biomarker association results in terms of biomarker effect modification of treatment efficacy, with detriment that the power calculations may tacitly and inadvertently assume that the treatment harms some study participants. We develop power and sample size methods accounting for this issue, and the methods also account for inter-individual variability of the biomarker that is not biologically relevant (e.g., due to technical measurement error). We focus on a binary study endpoint and on a biomarker subject to measurement error that is normally distributed or categorical with two or three levels. We illustrate the methods with preventive HIV vaccine efficacy trials, and include an R package implementing the methods. PMID:27037797

  6. Comparison of Registered and Reported Outcomes in Randomized Clinical Trials Published in Anesthesiology Journals.

    PubMed

    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

  7. Test-treatment RCTs are susceptible to bias: a review of the methodological quality of randomized trials that evaluate diagnostic tests.

    PubMed

    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

  8. 7 CFR 3017.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Adequate evidence. 3017.900 Section 3017.900 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  9. Comparison of inter-trial recovery times for the determination of critical power and W' in cycling.

    PubMed

    Karsten, Bettina; Hopker, James; Jobson, Simon A; Baker, Jonathan; Petrigna, Luca; Klose, Andreas; Beedie, Christopher

    2017-07-01

    Critical Power (CP) and W' are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W'. 9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p[Formula: see text] max ), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p[Formula: see text] max. Design: Protocol A utilised 24-h inter-trial recovery (CP 24 /W' 24 ), protocol B utilised 3-h inter-trial recovery (CP 3 /W' 3 ), and protocol C used 30-min inter-trial recovery period (CP 0.5 /W' 0.5 ). CP and W' were calculated using the inverse time (1/t) versus power (P) relation (P = W'(1/t) + CP). 95% Limits of Agreement between protocol A and B were -9 to 15 W; -7.4 to 7.8 kJ (CP/W') and between protocol A and protocol C they were -27 to 22 W; -7.2 to 15.1 kJ (CP/W'). Compared to criterion protocol A, the average prediction error of protocol B was 2.5% (CP) and 25.6% (W'), whilst for protocol C it was 3.7% (CP) and 32.9% (W'). 3-h and 30-min inter-trial recovery time protocols provide valid methods of determining CP but not W' in cycling.

  10. 29 CFR 98.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  11. 29 CFR 98.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  12. 29 CFR 98.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  13. 2 CFR 180.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  14. 2 CFR 180.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2 Grants and Agreements 1 2012-01-01 2012-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

  15. Understanding Statistical Power in Cluster Randomized Trials: Challenges Posed by Differences in Notation and Terminology

    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…

  16. Design of the value of imaging in enhancing the wellness of your heart (VIEW) trial and the impact of uncertainty on power.

    PubMed

    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

  17. Design of the Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) Trial and the Impact of Uncertainty on Power

    PubMed Central

    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

  18. Power, fairness and trust: understanding and engaging with vaccine trial participants and communities in the setting up the EBOVAC-Salone vaccine trial in Sierra Leone.

    PubMed

    Enria, Luisa; Lees, Shelley; Smout, Elizabeth; Mooney, Thomas; Tengbeh, Angus F; Leigh, Bailah; Greenwood, Brian; Watson-Jones, Deborah; Larson, Heidi

    2016-11-08

    This paper discusses the establishment of a clinical trial of an Ebola vaccine candidate in Kambia District, Northern Sierra Leone during the epidemic, and analyses the role of social science research in ensuring that lessons from the socio-political context, the recent experience of the Ebola outbreak, and learning from previous clinical trials were incorporated in the development of community engagement strategies. The paper aims to provide a case study of an integrated social science and communications system in the start-up phase of the clinical trial. The paper is based on qualitative research methods including ethnographic observation, interviews with trial participants and key stakeholder interviews. Through the case study of EBOVAC Salone, the paper suggests ways in which research can be used to inform communication strategies before and during the setting up of the trial. It explores notions of power, fairness and trust emerging from analysis of the Sierra Leonean context and through ethnographic research, to reflect on three situations in which social scientists and community liaison officers worked together to ensure successful community engagement. Firstly, a section on "power" considers the pitfalls of considering communities as homogeneous and shows the importance of understanding intra-community power dynamics when engaging communities. Secondly, a section on "fairness" shows how local understandings of what is fair can help inform the design of volunteer recruitment strategies. Finally, a section on "trust" highlights how historically rooted rumours can be effectively addressed through active dialogue rather than through an approach focused on correcting misinformation. The paper firstly emphasises the value of social science in the setting up of clinical trials, in terms of providing an in depth understanding of context and social dynamics. Secondly, the paper suggests the importance of a close collaboration between research and community

  19. Power of an Adaptive Trial Design for Endovascular Stroke Studies: Simulations Using IMS (Interventional Management of Stroke) III Data.

    PubMed

    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.

  20. A Calibrated Power Prior Approach to Borrow Information from Historical Data with Application to Biosimilar Clinical Trials.

    PubMed

    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.

  1. Transparency of Outcome Reporting and Trial Registration of Randomized Controlled Trials Published in the Journal of Consulting and Clinical Psychology

    PubMed Central

    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

  2. Transparency of Outcome Reporting and Trial Registration of Randomized Controlled Trials Published in the Journal of Consulting and Clinical Psychology.

    PubMed

    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

  3. Adequate sleep moderates the prospective association between alcohol use and consequences.

    PubMed

    Miller, Mary Beth; DiBello, Angelo M; Lust, Sarah A; Carey, Michael P; Carey, Kate B

    2016-12-01

    Inadequate sleep and heavy alcohol use have been associated with negative outcomes among college students; however, few studies have examined the interactive effects of sleep and drinking quantity in predicting alcohol-related consequences. This study aimed to determine if adequate sleep moderates the prospective association between weekly drinking quantity and consequences. College students (N=568) who were mandated to an alcohol prevention intervention reported drinks consumed per week, typical sleep quantity (calculated from sleep/wake times), and perceptions of sleep adequacy as part of a larger research trial. Assessments were completed at baseline and one-, three-, and five-month follow-ups. Higher baseline quantities of weekly drinking and inadequate sleep predicted alcohol-related consequences at baseline and one-month follow-up. Significant interactions emerged between baseline weekly drinking quantity and adequate sleep in the prediction of alcohol-related consequences at baseline, one-, three-, and five-month assessments. Simple slopes analyses revealed that weekly drinking quantity was positively associated with alcohol-related consequences for those reporting both adequate and inadequate sleep, but this association was consistently stronger among those who reported inadequate sleep. Subjective evaluation of sleep adequacy moderates both the concurrent and prospective associations between weekly drinking quantity and consequences, such that heavy-drinking college students reporting inadequate sleep experience more consequences as a result of drinking. Research needs to examine the mechanism(s) by which inadequate sleep affects alcohol risk among young adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Adaptive power priors with empirical Bayes for clinical trials.

    PubMed

    Gravestock, Isaac; Held, Leonhard

    2017-09-01

    Incorporating historical information into the design and analysis of a new clinical trial has been the subject of much discussion as a way to increase the feasibility of trials in situations where patients are difficult to recruit. The best method to include this data is not yet clear, especially in the case when few historical studies are available. This paper looks at the power prior technique afresh in a binomial setting and examines some previously unexamined properties, such as Box P values, bias, and coverage. Additionally, it proposes an empirical Bayes-type approach to estimating the prior weight parameter by marginal likelihood. This estimate has advantages over previously criticised methods in that it varies commensurably with differences in the historical and current data and can choose weights near 1 when the data are similar enough. Fully Bayesian approaches are also considered. An analysis of the operating characteristics shows that the adaptive methods work well and that the various approaches have different strengths and weaknesses. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Blinded sample size re-estimation in three-arm trials with 'gold standard' design.

    PubMed

    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.

  6. Statistical power in parallel group point exposure studies with time-to-event outcomes: an empirical comparison of the performance of randomized controlled trials and the inverse probability of treatment weighting (IPTW) approach.

    PubMed

    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.

  7. A community-based randomized controlled trial of Mom Power parenting intervention for mothers with interpersonal trauma histories and their young children.

    PubMed

    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.

  8. Overview of phase IV clinical trials for postmarket drug safety surveillance: a status report from the ClinicalTrials.gov registry.

    PubMed

    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/.

  9. Research information knowledge, perceived adequacy, and understanding in cancer clinical trial participants.

    PubMed

    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.

  10. The Importance and Role of Intracluster Correlations in Planning Cluster Trials

    PubMed Central

    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

  11. 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.

  12. Caution regarding the choice of standard deviations to guide sample size calculations in clinical trials.

    PubMed

    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

  13. 5 CFR 919.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  14. 5 CFR 919.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  15. 5 CFR 919.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  16. 5 CFR 919.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  17. 5 CFR 919.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  18. Survival distributions impact the power of randomized placebo-phase design and parallel groups randomized clinical trials.

    PubMed

    Abrahamyan, Lusine; Li, Chuan Silvia; Beyene, Joseph; Willan, Andrew R; Feldman, Brian M

    2011-03-01

    The study evaluated the power of the randomized placebo-phase design (RPPD)-a new design of randomized clinical trials (RCTs), compared with the traditional parallel groups design, assuming various response time distributions. In the RPPD, at some point, all subjects receive the experimental therapy, and the exposure to placebo is for only a short fixed period of time. For the study, an object-oriented simulation program was written in R. The power of the simulated trials was evaluated using six scenarios, where the treatment response times followed the exponential, Weibull, or lognormal distributions. The median response time was assumed to be 355 days for the placebo and 42 days for the experimental drug. Based on the simulation results, the sample size requirements to achieve the same level of power were different under different response time to treatment distributions. The scenario where the response times followed the exponential distribution had the highest sample size requirement. In most scenarios, the parallel groups RCT had higher power compared with the RPPD. The sample size requirement varies depending on the underlying hazard distribution. The RPPD requires more subjects to achieve a similar power to the parallel groups design. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Thinking clearly about the FIRST trial: addressing ethical challenges in cluster randomised trials of policy interventions involving health providers.

    PubMed

    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.

  20. Effects of prophylactic indomethacin in extremely low-birth-weight infants with and without adequate exposure to antenatal corticosteroids.

    PubMed

    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.

  1. 2 CFR 180.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  2. 2 CFR 180.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

  3. The Consolidated Standards of Reporting Trials (CONSORT) Statement applied to allergen-specific immunotherapy with inhalant allergens: a Global Allergy and Asthma European Network (GA(2)LEN) article.

    PubMed

    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.

  4. Bias, precision and statistical power of analysis of covariance in the analysis of randomized trials with baseline imbalance: a simulation study.

    PubMed

    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.

  5. Bias, precision and statistical power of analysis of covariance in the analysis of randomized trials with baseline imbalance: a simulation study

    PubMed Central

    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

  6. Statistical inference on censored data for targeted clinical trials under enrichment design.

    PubMed

    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.

  7. Continuous Covariate Imbalance and Conditional Power for Clinical Trial Interim Analyses

    PubMed Central

    Ciolino, Jody D.; Martin, Renee' H.; Zhao, Wenle; Jauch, Edward C.; Hill, Michael D.; Palesch, Yuko Y.

    2014-01-01

    Oftentimes valid statistical analyses for clinical trials involve adjustment for known influential covariates, regardless of imbalance observed in these covariates at baseline across treatment groups. Thus, it must be the case that valid interim analyses also properly adjust for these covariates. There are situations, however, in which covariate adjustment is not possible, not planned, or simply carries less merit as it makes inferences less generalizable and less intuitive. In this case, covariate imbalance between treatment groups can have a substantial effect on both interim and final primary outcome analyses. This paper illustrates the effect of influential continuous baseline covariate imbalance on unadjusted conditional power (CP), and thus, on trial decisions based on futility stopping bounds. The robustness of the relationship is illustrated for normal, skewed, and bimodal continuous baseline covariates that are related to a normally distributed primary outcome. Results suggest that unadjusted CP calculations in the presence of influential covariate imbalance require careful interpretation and evaluation. PMID:24607294

  8. Hierarchical Commensurate and Power Prior Models for Adaptive Incorporation of Historical Information in Clinical Trials

    PubMed Central

    Hobbs, Brian P.; Carlin, Bradley P.; Mandrekar, Sumithra J.; Sargent, Daniel J.

    2011-01-01

    Summary Bayesian clinical trial designs offer the possibility of a substantially reduced sample size, increased statistical power, and reductions in cost and ethical hazard. However when prior and current information conflict, Bayesian methods can lead to higher than expected Type I error, as well as the possibility of a costlier and lengthier trial. This motivates an investigation of the feasibility of hierarchical Bayesian methods for incorporating historical data that are adaptively robust to prior information that reveals itself to be inconsistent with the accumulating experimental data. In this paper, we present several models that allow for the commensurability of the information in the historical and current data to determine how much historical information is used. A primary tool is elaborating the traditional power prior approach based upon a measure of commensurability for Gaussian data. We compare the frequentist performance of several methods using simulations, and close with an example of a colon cancer trial that illustrates a linear models extension of our adaptive borrowing approach. Our proposed methods produce more precise estimates of the model parameters, in particular conferring statistical significance to the observed reduction in tumor size for the experimental regimen as compared to the control regimen. PMID:21361892

  9. Trial application of reliability technology to emergency diesel generators at the Trojan Nuclear Power Plant

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

    Wong, S.M.; Boccio, J.L.; Karimian, S.

    1986-01-01

    In this paper, a trial application of reliability technology to the emergency diesel generator system at the Trojan Nuclear Power Plant is presented. An approach for formulating a reliability program plan for this system is being developed. The trial application has shown that a reliability program process, using risk- and reliability-based techniques, can be interwoven into current plant operational activities to help in controlling, analyzing, and predicting faults that can challenge safety systems. With the cooperation of the utility, Portland General Electric Co., this reliability program can eventually be implemented at Trojan to track its effectiveness.

  10. Pacing Strategy in Short Cycling Time Trials.

    PubMed

    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.

  11. Assessment and Implication of Prognostic Imbalance in Randomized Controlled Trials with a Binary Outcome – A Simulation Study

    PubMed Central

    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

  12. Rectal cancer delivery of radiotherapy in adequate time and with adequate dose is influenced by treatment center, treatment schedule, and gender and is prognostic parameter for local control: Results of study CAO/ARO/AIO-94

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

    Fietkau, Rainer; Roedel, Claus; Hohenberger, Werner

    2007-03-15

    Purpose: The impact of the delivery of radiotherapy (RT) on treatment results in rectal cancer patients is unknown. Methods and Materials: The data from 788 patients with rectal cancer treated within the German CAO/AIO/ARO-94 phase III trial were analyzed concerning the impact of the delivery of RT (adequate RT: minimal radiation RT dose delivered, 4300 cGy for neoadjuvant RT or 4700 cGy for adjuvant RT; completion of RT in <44 days for neoadjuvant RT or <49 days for adjuvant RT) in different centers on the locoregional recurrence rate (LRR) and disease-free survival (DFS) at 5 years. The LRR, DFS, andmore » delivery of RT were analyzed as endpoints in multivariate analysis. Results: A significant difference was found between the centers and the delivery of RT. The overall delivery of RT was a prognostic factor for the LRR (no RT, 29.6% {+-} 7.8%; inadequate RT, 21.2% {+-} 5.6%; adequate RT, 6.8% {+-} 1.4%; p = 0.0001) and DFS (no RT, 55.1% {+-} 9.1%; inadequate RT, 57.4% {+-} 6.3%; adequate RT, 69.1% {+-} 2.3%; p = 0.02). Postoperatively, delivery of RT was a prognostic factor for LRR on multivariate analysis (together with pathologic stage) but not for DFS (independent parameters, pathologic stage and age). Preoperatively, on multivariate analysis, pathologic stage, but not delivery of RT, was an independent prognostic parameter for LRR and DFS (together with adequate chemotherapy). On multivariate analysis, the treatment center, treatment schedule (neoadjuvant vs. adjuvant RT), and gender were prognostic parameters for adequate RT. Conclusion: Delivery of RT should be regarded as a prognostic factor for LRR in rectal cancer and is influenced by the treatment center, treatment schedule, and patient gender.« less

  13. GOST: A generic ordinal sequential trial design for a treatment trial in an emerging pandemic.

    PubMed

    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

  14. 41 CFR 105-68.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Adequate evidence. 105-68.900 Section 105-68.900 Public Contracts and Property Management Federal Property Management... evidence. Adequate evidence means information sufficient to support the reasonable belief that a particular...

  15. 41 CFR 105-68.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Adequate evidence. 105-68.900 Section 105-68.900 Public Contracts and Property Management Federal Property Management... evidence. Adequate evidence means information sufficient to support the reasonable belief that a particular...

  16. 41 CFR 105-68.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Adequate evidence. 105-68.900 Section 105-68.900 Public Contracts and Property Management Federal Property Management... evidence. Adequate evidence means information sufficient to support the reasonable belief that a particular...

  17. 41 CFR 105-68.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Adequate evidence. 105-68.900 Section 105-68.900 Public Contracts and Property Management Federal Property Management... evidence. Adequate evidence means information sufficient to support the reasonable belief that a particular...

  18. 41 CFR 105-68.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Adequate evidence. 105-68.900 Section 105-68.900 Public Contracts and Property Management Federal Property Management... evidence. Adequate evidence means information sufficient to support the reasonable belief that a particular...

  19. A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

    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…

  20. Peyronie's disease intervention trials: methodological challenges and issues.

    PubMed

    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.

  1. Are large clinical trials in orthopaedic trauma justified?

    PubMed

    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.

  2. Interactive Book Reading to Accelerate Word Learning by Kindergarten Children With Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response.

    PubMed

    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.

  3. Interactive Book Reading to Accelerate Word Learning by Kindergarten Children With Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response

    PubMed Central

    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

  4. Pooling of cross-cultural PRO data in multinational clinical trials: how much can poor measurement affect statistical power?

    PubMed

    Regnault, Antoine; Hamel, Jean-François; Patrick, Donald L

    2015-02-01

    Cultural differences and/or poor linguistic validation of patient-reported outcome (PRO) instruments may result in differences in the assessment of the targeted concept across languages. In the context of multinational clinical trials, these measurement differences may add noise and potentially measurement bias to treatment effect estimation. Our objective was to explore the potential effect on treatment effect estimation of the "contamination" of a cultural subgroup by a flawed PRO measurement. We ran a simulation exercise in which the distribution of the score in the overall sample was considered a mixture of two normal distributions: a standard normal distribution was assumed in a "main" subgroup and a normal distribution which differed either in mean (bias) or in variance (noise) in a "contaminated" subgroup (the subgroup with potential flaws in the PRO measurement). The observed power was compared to the expected power (i.e., the power that would have been observed if the subgroup had not been contaminated). Even if differences between the expected and observed power were small, some substantial differences were obtained (up to a 0.375 point drop in power). No situation was systematically protected against loss of power. The impact of poor PRO measurement in a cultural subgroup may induce a notable drop in the study power and consequently reduce the chance of showing an actual treatment effect. These results illustrate the importance of the efforts to optimize conceptual and linguistic equivalence of PRO measures when pooling data in international clinical trials.

  5. 40 CFR 716.25 - Adequate file search.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Adequate file search. 716.25 Section 716.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.25 Adequate file search. The scope of a...

  6. 40 CFR 716.25 - Adequate file search.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Adequate file search. 716.25 Section 716.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.25 Adequate file search. The scope of a...

  7. 40 CFR 716.25 - Adequate file search.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Adequate file search. 716.25 Section 716.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.25 Adequate file search. The scope of a...

  8. 40 CFR 716.25 - Adequate file search.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Adequate file search. 716.25 Section 716.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.25 Adequate file search. The scope of a...

  9. 40 CFR 716.25 - Adequate file search.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Adequate file search. 716.25 Section 716.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.25 Adequate file search. The scope of a...

  10. Adequate supervision for children and adolescents.

    PubMed

    Anderst, James; Moffatt, Mary

    2014-11-01

    Primary care providers (PCPs) have the opportunity to improve child health and well-being by addressing supervision issues before an injury or exposure has occurred and/or after an injury or exposure has occurred. Appropriate anticipatory guidance on supervision at well-child visits can improve supervision of children, and may prevent future harm. Adequate supervision varies based on the child's development and maturity, and the risks in the child's environment. Consideration should be given to issues as wide ranging as swimming pools, falls, dating violence, and social media. By considering the likelihood of harm and the severity of the potential harm, caregivers may provide adequate supervision by minimizing risks to the child while still allowing the child to take "small" risks as needed for healthy development. Caregivers should initially focus on direct (visual, auditory, and proximity) supervision of the young child. Gradually, supervision needs to be adjusted as the child develops, emphasizing a safe environment and safe social interactions, with graduated independence. PCPs may foster adequate supervision by providing concrete guidance to caregivers. In addition to preventing injury, supervision includes fostering a safe, stable, and nurturing relationship with every child. PCPs should be familiar with age/developmentally based supervision risks, adequate supervision based on those risks, characteristics of neglectful supervision based on age/development, and ways to encourage appropriate supervision throughout childhood. Copyright 2014, SLACK Incorporated.

  11. Follow-up of colorectal cancer patients after resection with curative intent-the GILDA trial.

    PubMed

    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.

  12. Methodological reporting quality of randomized controlled trials: A survey of seven core journals of orthopaedics from Mainland China over 5 years following the CONSORT statement.

    PubMed

    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

  13. 10 CFR 1304.114 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Responsibility for maintaining adequate safeguards. 1304.114 Section 1304.114 Energy NUCLEAR WASTE TECHNICAL REVIEW BOARD PRIVACY ACT OF 1974 § 1304.114 Responsibility for maintaining adequate safeguards. The Board has the responsibility for maintaining adequate...

  14. 10 CFR 1304.114 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Responsibility for maintaining adequate safeguards. 1304.114 Section 1304.114 Energy NUCLEAR WASTE TECHNICAL REVIEW BOARD PRIVACY ACT OF 1974 § 1304.114 Responsibility for maintaining adequate safeguards. The Board has the responsibility for maintaining adequate...

  15. 10 CFR 1304.114 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Responsibility for maintaining adequate safeguards. 1304.114 Section 1304.114 Energy NUCLEAR WASTE TECHNICAL REVIEW BOARD PRIVACY ACT OF 1974 § 1304.114 Responsibility for maintaining adequate safeguards. The Board has the responsibility for maintaining adequate...

  16. 10 CFR 1304.114 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Responsibility for maintaining adequate safeguards. 1304.114 Section 1304.114 Energy NUCLEAR WASTE TECHNICAL REVIEW BOARD PRIVACY ACT OF 1974 § 1304.114 Responsibility for maintaining adequate safeguards. The Board has the responsibility for maintaining adequate...

  17. Bayesian adaptive trials offer advantages in comparative effectiveness trials: an example in status epilepticus.

    PubMed

    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.

  18. Interactive Book Reading to Accelerate Word Learning by Kindergarten Children with Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response

    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…

  19. Controlled Trials in Children: Quantity, Methodological Quality and Descriptive Characteristics of Pediatric Controlled Trials Published 1948-2006

    PubMed Central

    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

  20. Controlled trials in children: quantity, methodological quality and descriptive characteristics of pediatric controlled trials published 1948-2006.

    PubMed

    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

  1. Incorporating BIRD-based homodecoupling in the dual-optimized, inverted 1 JCC 1,n-ADEQUATE experiment.

    PubMed

    Saurí, Josep; Bermel, Wolfgang; Parella, Teodor; Thomas Williamson, R; Martin, Gary E

    2018-03-13

    1,n-ADEQUATE is a powerful NMR technique for elucidating the structure of proton-deficient small molecules that can help establish the carbon skeleton of a given molecule by providing long-range three-bond 13 C─ 13 C correlations. Care must be taken when using the experiment to identify the simultaneous presence of one-bond 13 C─ 13 C correlations that are not filtered out, unlike the HMBC experiment that has a low-pass J-filter to filter 1 J CH responses out. Dual-optimized, inverted 1 J CC 1,n-ADEQUATE is an improved variant of the experiment that affords broadband inversion of direct responses, obviating the need to take additional steps to identify these correlations. Even though ADEQUATE experiments can now be acquired in a reasonable amount of experimental time if a cryogenic probe is available, low sensitivity is still the main impediment limiting the application of this elegant experiment. Here, we wish to report a further refinement that incorporates real-time bilinear rotation decoupling-based homodecoupling methodology into the dual-optimized, inverted 1 J CC 1,n-ADEQUATE pulse sequence. Improved sensitivity and resolution are achieved by collapsing homonuclear proton-proton couplings from the observed multiplets for most spin systems. The application of the method is illustrated with several model compounds. Copyright © 2018 John Wiley & Sons, Ltd.

  2. Comparison of design strategies for a three-arm clinical trial with time-to-event endpoint: Power, time-to-analysis, and operational aspects.

    PubMed

    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.

  3. Robust inference for group sequential trials.

    PubMed

    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.

  4. Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

    PubMed

    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.

  5. Accuracy of the Velotron ergometer and SRM power meter.

    PubMed

    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.

  6. Have Clinical Trials Properly Assessed c-Met Inhibitors?

    PubMed

    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.

  7. Sample size requirements for separating out the effects of combination treatments: randomised controlled trials of combination therapy vs. standard treatment compared to factorial designs for patients with tuberculous meningitis.

    PubMed

    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

  8. 40 CFR 51.354 - Adequate tools and resources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Adequate tools and resources. 51.354... Requirements § 51.354 Adequate tools and resources. (a) Administrative resources. The program shall maintain... assurance, data analysis and reporting, and the holding of hearings and adjudication of cases. A portion of...

  9. 40 CFR 51.354 - Adequate tools and resources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Adequate tools and resources. 51.354... Requirements § 51.354 Adequate tools and resources. (a) Administrative resources. The program shall maintain... assurance, data analysis and reporting, and the holding of hearings and adjudication of cases. A portion of...

  10. 40 CFR 51.354 - Adequate tools and resources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Adequate tools and resources. 51.354... Requirements § 51.354 Adequate tools and resources. (a) Administrative resources. The program shall maintain... assurance, data analysis and reporting, and the holding of hearings and adjudication of cases. A portion of...

  11. 40 CFR 51.354 - Adequate tools and resources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Adequate tools and resources. 51.354... Requirements § 51.354 Adequate tools and resources. (a) Administrative resources. The program shall maintain... assurance, data analysis and reporting, and the holding of hearings and adjudication of cases. A portion of...

  12. Auditory Stimulus Processing and Task Learning Are Adequate in Dyslexia, but Benefits From Regularities Are Reduced.

    PubMed

    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.

  13. Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy.

    PubMed

    Fintelman, D M; Sterling, M; Hemida, H; Li, F-X

    2014-06-03

    The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. An alternative clinical routine for subjective refraction based on power vectors with trial frames.

    PubMed

    María Revert, Antonia; Conversa, Maria Amparo; Albarrán Diego, César; Micó, Vicente

    2017-01-01

    Subjective refraction determines the final point of refractive error assessment in most clinical environments and its foundations have remained unchanged for decades. The purpose of this paper is to compare the results obtained when monocular subjective refraction is assessed in trial frames by a new clinical procedure based on a pure power vector interpretation with conventional clinical refraction procedures. An alternative clinical routine is described that uses power vector interpretation with implementation in trial frames. Refractive error is determined in terms of: (i) the spherical equivalent (M component), and (ii) a pair of Jackson Crossed Cylinder lenses oriented at 0°/90° (J 0 component) and 45°/135° (J 45 component) for determination of astigmatism. This vector subjective refraction result (VR) is compared separately for right and left eyes of 25 subjects (mean age, 35 ± 4 years) against conventional sphero-cylindrical subjective refraction (RX) using a phoropter. The VR procedure was applied with both conventional tumbling E optotypes (VR1) and modified optotypes with oblique orientation (VR2). Bland-Altman plots and intra-class correlation coefficient showed good agreement between VR, and RX (with coefficient values above 0.82) and anova showed no significant differences in any of the power vector components between RX and VR. VR1 and VR2 procedure results were similar (p ≥ 0.77). The proposed routine determines the three components of refractive error in power vector notation [M, J 0 , J 45 ], with a refraction time similar to the one used in conventional subjective procedures. The proposed routine could be helpful for inexperienced clinicians and for experienced clinicians in those cases where it is difficult to get a valid starting point for conventional RX (irregular corneas, media opacities, etc.) and for refractive situations/places with inadequate refractive facilities/equipment. © 2016 The Authors Ophthalmic & Physiological

  15. An imbalance in cluster sizes does not lead to notable loss of power in cross-sectional, stepped-wedge cluster randomised trials with a continuous outcome.

    PubMed

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

    2017-03-07

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

  16. Contemporary Aspects of Marketing in Clinical Trials Including Segments of IT and Technology Transfer

    PubMed Central

    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

  17. Contemporary Aspects of Marketing in Clinical Trials Including Segments of IT and Technology Transfer.

    PubMed

    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.

  18. Hydrolyzed Formula With Reduced Protein Content Supports Adequate Growth: A Randomized Controlled Noninferiority Trial.

    PubMed

    Ahrens, Birgit; Hellmuth, Christian; Haiden, Nadja; Olbertz, Dirk; Hamelmann, Eckard; Vusurovic, Milica; Fleddermann, Manja; Roehle, Robert; Knoll, Anette; Koletzko, Berthold; Wahn, Ulrich; Beyer, Kirsten

    2018-05-01

    A high protein content of nonhydrolyzed infant formula exceeding metabolic requirements can induce rapid weight gain and obesity. Hydrolyzed formula with too low protein (LP) content may result in inadequate growth. The aim of this study was to investigate noninferiority of partial and extensively hydrolyzed formulas (pHF, eHF) with lower hydrolyzed protein content than conventionally, regularly used formulas, with or without synbiotics for normal growth of healthy term infants. In an European multi-center, parallel, prospective, controlled, double-blind trial, 402 formula-fed infants were randomly assigned to four groups: LP-formulas (1.9 g protein/100 kcal) as pHF with or without synbiotics, LP-eHF formula with synbiotics, or regular protein eHF (2.3 g protein/100 kcal). One hundred and one breast-fed infants served as observational reference group. As primary endpoint, noninferiority of daily weight gain during the first 4 months of life was investigated comparing the LP-group to a regular protein eHF group. A comparison of daily weight gain in infants receiving LPpHF (2.15 g/day CI -0.18 to inf.) with infants receiving regular protein eHF showed noninferior weight gain (-3.5 g/day margin; per protocol [PP] population). Noninferiority was also confirmed for the other tested LP formulas. Likewise, analysis of metabolic parameters and plasma amino acid concentrations demonstrated a safe and balanced nutritional composition. Energetic efficiency for growth (weight) was slightly higher in LPeHF and synbiotics compared with LPpHF and synbiotics. All tested hydrolyzed LP formulas allowed normal weight gain without being inferior to regular protein eHF in the first 4 months of life. This trial was registered at clinicaltrials.gov, NCT01143233.

  19. Designing clinical trials to test disease-modifying agents: application to the treatment trials of Alzheimer's disease.

    PubMed

    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

  20. Measurements of experimental precision for trials with cowpea (Vigna unguiculata L. Walp.) genotypes.

    PubMed

    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.

  1. 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.

  2. A practical Bayesian stepped wedge design for community-based cluster-randomized clinical trials: The British Columbia Telehealth Trial.

    PubMed

    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

  3. Predictors of adequate depression treatment among Medicaid-enrolled adults.

    PubMed

    Teh, Carrie Farmer; Sorbero, Mark J; Mihalyo, Mark J; Kogan, Jane N; Schuster, James; Reynolds, Charles F; Stein, Bradley D

    2010-02-01

    To determine whether Medicaid-enrolled depressed adults receive adequate treatment for depression and to identify the characteristics of those receiving inadequate treatment. Claims data from a Medicaid-enrolled population in a large mid-Atlantic state between July 2006 and January 2008. We examined rates and predictors of minimally adequate psychotherapy and pharmacotherapy among adults with a new depression treatment episode during the study period (N=1,098). Many depressed adults received either minimally adequate psychotherapy or pharmacotherapy. Black individuals and individuals who began their depression treatment episode with an inpatient psychiatric stay for depression were markedly less likely to receive minimally adequate psychotherapy and more likely to receive inadequate treatment. Racial minorities and individuals discharged from inpatient treatment for depression are at risk for receiving inadequate depression treatment.

  4. Sample size requirements for separating out the effects of combination treatments: Randomised controlled trials of combination therapy vs. standard treatment compared to factorial designs for patients with tuberculous meningitis

    PubMed Central

    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

  5. Protocol for a randomised controlled trial of fetal scalp blood lactate measurement to reduce caesarean sections during labour: the Flamingo trial [ACTRN12611000172909].

    PubMed

    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

  6. 22 CFR 1006.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Adequate evidence. 1006.900 Section 1006.900 Foreign Relations INTER-AMERICAN FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT... reasonable belief that a particular act or omission has occurred. ...

  7. 22 CFR 1508.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Adequate evidence. 1508.900 Section 1508.900 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT... reasonable belief that a particular act or omission has occurred. ...

  8. Joint probability of statistical success of multiple phase III trials.

    PubMed

    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.

  9. Randomised trials comparing different healthcare settings: an exploratory review of the impact of pre-trial preferences on participation, and discussion of other methodological challenges.

    PubMed

    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

  10. Reporting non-adherence in cluster randomised trials: A systematic review.

    PubMed

    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

  11. Using simulation to aid trial design: Ring-vaccination trials.

    PubMed

    Hitchings, Matt David Thomas; Grais, Rebecca Freeman; Lipsitch, Marc

    2017-03-01

    The 2014-6 West African Ebola epidemic highlights the need for rigorous, rapid clinical trial methods for vaccines. A challenge for trial design is making sample size calculations based on incidence within the trial, total vaccine effect, and intracluster correlation, when these parameters are uncertain in the presence of indirect effects of vaccination. We present a stochastic, compartmental model for a ring vaccination trial. After identification of an index case, a ring of contacts is recruited and either vaccinated immediately or after 21 days. The primary outcome of the trial is total vaccine effect, counting cases only from a pre-specified window in which the immediate arm is assumed to be fully protected and the delayed arm is not protected. Simulation results are used to calculate necessary sample size and estimated vaccine effect. Under baseline assumptions about vaccine properties, monthly incidence in unvaccinated rings and trial design, a standard sample-size calculation neglecting dynamic effects estimated that 7,100 participants would be needed to achieve 80% power to detect a difference in attack rate between arms, while incorporating dynamic considerations in the model increased the estimate to 8,900. This approach replaces assumptions about parameters at the ring level with assumptions about disease dynamics and vaccine characteristics at the individual level, so within this framework we were able to describe the sensitivity of the trial power and estimated effect to various parameters. We found that both of these quantities are sensitive to properties of the vaccine, to setting-specific parameters over which investigators have little control, and to parameters that are determined by the study design. Incorporating simulation into the trial design process can improve robustness of sample size calculations. For this specific trial design, vaccine effectiveness depends on properties of the ring vaccination design and on the measurement window, as

  12. 22 CFR 208.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Adequate evidence. 208.900 Section 208.900 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  13. 22 CFR 208.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Adequate evidence. 208.900 Section 208.900 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  14. 10 CFR 503.35 - Inability to obtain adequate capital.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... capital investment, through tariffs, without unreasonably adverse economic effect on its service area... 10 Energy 4 2010-01-01 2010-01-01 false Inability to obtain adequate capital. 503.35 Section 503... New Facilities § 503.35 Inability to obtain adequate capital. (a) Eligibility. Section 212(a)(1)(D) of...

  15. "Something Adequate"? In Memoriam Seamus Heaney, Sister Quinlan, Nirbhaya

    ERIC Educational Resources Information Center

    Parker, Jan

    2014-01-01

    Seamus Heaney talked of poetry's responsibility to represent the "bloody miracle", the "terrible beauty" of atrocity; to create "something adequate". This article asks, what is adequate to the burning and eating of a nun and the murderous gang rape and evisceration of a medical student? It considers Njabulo Ndebele's…

  16. 2 CFR 180.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS... belief that a particular act or omission has occurred. ...

  17. 21 CFR 1404.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Adequate evidence. 1404.900 Section 1404.900 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  18. 29 CFR 1471.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Adequate evidence. 1471.900 Section 1471.900 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT... information sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  19. 21 CFR 1404.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Adequate evidence. 1404.900 Section 1404.900 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  20. 29 CFR 1471.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Adequate evidence. 1471.900 Section 1471.900 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT... information sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  1. 29 CFR 1471.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Adequate evidence. 1471.900 Section 1471.900 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT... information sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  2. 21 CFR 1404.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Adequate evidence. 1404.900 Section 1404.900 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  3. 21 CFR 1404.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Adequate evidence. 1404.900 Section 1404.900 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  4. 29 CFR 1471.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Adequate evidence. 1471.900 Section 1471.900 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT... information sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  5. 21 CFR 1404.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Adequate evidence. 1404.900 Section 1404.900 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION... support the reasonable belief that a particular act or omission has occurred. ...

  6. 29 CFR 1471.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Adequate evidence. 1471.900 Section 1471.900 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT... information sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  7. Solar Power Satellite (SPS) solid-state antenna power combiner

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A low loss power-combining microstrip antenna suitable for solid state solar power satellite (SPS) application was developed. A unique approach for performing both the combining and radiating function in a single cavity-type circuit was verified, representing substantial refinements over previous demonstration models in terms of detailed geometry to obtain good matching and adequate bandwidth at the design frequency. The combiner circuit was designed, built, and tested and the overall results support the view that the solid state power-combining antenna approach is a viable candidate for a solid state SPS antenna building block.

  8. Predicting High-Power Performance in Professional Cyclists.

    PubMed

    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.

  9. Evaluating Intermittent Androgen-Deprivation Therapy Phase III Clinical Trials: The Devil Is in the Details.

    PubMed

    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.

  10. 31 CFR 19.900 - Adequate evidence.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Adequate evidence. 19.900 Section 19.900 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND... sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  11. 31 CFR 19.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Adequate evidence. 19.900 Section 19.900 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND... sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  12. 34 CFR 85.900 - Adequate evidence.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Adequate evidence. 85.900 Section 85.900 Education Office of the Secretary, Department of Education GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT... reasonable belief that a particular act or omission has occurred. (Authority: E.O. 12549 (3 CFR, 1986 Comp...

  13. 31 CFR 19.900 - Adequate evidence.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Adequate evidence. 19.900 Section 19.900 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND... sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  14. 31 CFR 19.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Adequate evidence. 19.900 Section 19.900 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND... sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  15. 34 CFR 85.900 - Adequate evidence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Adequate evidence. 85.900 Section 85.900 Education Office of the Secretary, Department of Education GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT... reasonable belief that a particular act or omission has occurred. Authority: E.O. 12549 (3 CFR, 1986 Comp., p...

  16. 31 CFR 19.900 - Adequate evidence.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Adequate evidence. 19.900 Section 19.900 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND... sufficient to support the reasonable belief that a particular act or omission has occurred. ...

  17. Methodological Reporting Quality of Randomized Controlled Trials in 3 Leading Diabetes Journals From 2011 to 2013 Following CONSORT Statement: A System Review.

    PubMed

    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.

  18. Do randomized clinical trials with inadequate blinding report enhanced placebo effects for intervention groups and nocebo effects for placebo groups?

    PubMed Central

    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

  19. Mechanochemical endovenous ablation versus radiofrequency ablation in the treatment of primary small saphenous vein insufficiency (MESSI trial): study protocol for a randomized controlled trial.

    PubMed

    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

  20. The Trial Software version for DEMETER power spectrum files visualization and mapping

    NASA Astrophysics Data System (ADS)

    Lozbin, Anatoliy; Inchin, Alexander; Shpadi, Maxim

    2010-05-01

    In the frame of Kazakhstan's Scientific Space System creation for earthquakes precursors research, the hardware and software of DEMETER satellite was investigated. The data processing Software of DEMETER is based on package SWAN under IDL Virtual machine and realizes many features, but we can't find an important tool for the spectrograms analysis - space-time visualization of power spectrum files from electromagnetic devices as ICE and IMSC. For elimination of this problem we have developed Software which is offered to use. The DeSS (DEMETER Spectrogram Software) - it is Software for visualization, analysis and a mapping of power spectrum data from electromagnetic devices ICE and IMSC. The Software primary goal is to give the researcher friendly tool for the analysis of electromagnetic data from DEMETER Satellite for earthquake precursors and other ionosphere events researches. The Input data for DeSS Software is a power spectrum files: - Power spectrum of 1 component of the electric field in the VLF range (APID 1132); - Power spectrum of 1 component of the electric field in the HF range (APID 1134); - Power spectrum of 1 component of the magnetic field in the VLF range (APID 1137). The main features and operations of the software is possible: - various time and frequency filtration; - visualization of time dependence of signal intensity on fixed frequency; - spectral density visualization for fixed frequency range; - spectrogram autosize and smooth spectrogram; - the information in each point of the spectrogram: time, frequency and intensity; - the spectrum information in the separate window, consisting of 4 blocks; - data mapping with 6 range scale. On the map we can browse next information: - satellite orbit; - conjugate point at the satellite altitude; - north conjugate point at the altitude 110 km; - south conjugate point at the altitude 110 km. This is only trial software version to help the researchers and we always ready collaborate with scientists for

  1. Reporting of harm and safety results in randomized controlled trials published in 5 dermatology journals.

    PubMed

    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.

  2. Five-year results of a randomised controlled trial comparing mobile and fixed bearings in total knee replacement.

    PubMed

    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.

  3. 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.

  4. The art and science of choosing efficacy endpoints for rare disease clinical trials.

    PubMed

    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.

  5. Powered versus manual toothbrushing for oral health.

    PubMed

    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

  6. Independent but coordinated trials: insights from the practice-based Opportunities for Weight Reduction Trials Collaborative Research Group.

    PubMed

    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.

  7. Power output measurement during treadmill cycling.

    PubMed

    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.

  8. 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…

  9. Funding the Formula Adequately in Oklahoma

    ERIC Educational Resources Information Center

    Hancock, Kenneth

    2015-01-01

    This report is a longevity, simulational study that looks at how the ratio of state support to local support effects the number of school districts that breaks the common school's funding formula which in turns effects the equity of distribution to the common schools. After nearly two decades of adequately supporting the funding formula, Oklahoma…

  10. The effect of extrinsic motivation on cycle time trial performance.

    PubMed

    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.

  11. Hypothesis testing in clinical trials.

    PubMed

    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.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Aura interruption: the Andrews/Reiter behavioral intervention may reduce seizures and improve quality of life - a pilot trial.

    PubMed

    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.

  17. Clinical Trials of Potential Cognitive-Enhancing Drugs in Schizophrenia: What Have We Learned So Far?

    PubMed Central

    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

  18. 9 CFR 2.33 - Attending veterinarian and adequate veterinary care.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... veterinary care. 2.33 Section 2.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... adequate veterinary care. (a) Each research facility shall have an attending veterinarian who shall provide adequate veterinary care to its animals in compliance with this section: (1) Each research facility shall...

  19. 9 CFR 2.33 - Attending veterinarian and adequate veterinary care.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... veterinary care. 2.33 Section 2.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... adequate veterinary care. (a) Each research facility shall have an attending veterinarian who shall provide adequate veterinary care to its animals in compliance with this section: (1) Each research facility shall...

  20. Surrogate endpoints for cancer screening trials: general principles and an illustration using the UK Flexible Sigmoidoscopy Screening Trial.

    PubMed

    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.

  1. Assessing the detection, reporting and investigation of adverse events in clinical trial protocols implemented in Cameroon: a documentary review of clinical trial protocols.

    PubMed

    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

  2. Systematic evaluation of the methodology of randomized controlled trials of anticoagulation in patients with cancer.

    PubMed

    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

  3. Parents' perceived obstacles to pediatric clinical trial participation: Findings from the clinical trials transformation initiative.

    PubMed

    Greenberg, Rachel G; Gamel, Breck; Bloom, Diane; Bradley, John; Jafri, Hasan S; Hinton, Denise; Nambiar, Sumathi; Wheeler, Chris; Tiernan, Rosemary; Smith, P Brian; Roberts, Jamie; Benjamin, Daniel K

    2018-03-01

    Enrollment of children into pediatric clinical trials remains challenging. More effective strategies to improve recruitment of children into trials are needed. This study used in-depth qualitative interviews with parents who were approached to enroll their children in a clinical trial in order to gain an understanding of the barriers to pediatric clinical trial participation. Twenty-four parents whose children had been offered the opportunity to participate in a clinical trial were interviewed: 19 whose children had participated in at least 1 clinical trial and 5 who had declined participation in any trial. Each study aspect, from the initial explanation of the study to the end of the study, can affect the willingness of parents to consent to the proposed study and future studies. Establishing trust, appropriate timing, a transparent discussion of risks and benefits oriented to the layperson, and providing motivation for children to participate were key factors that impacted parents' decisions. In order for clinical trial accrual to be successful, parents' priorities and considerations must be a central focus, beginning with initial trial design. The recommendations from the parents who participated in this study can be used to support budget allocations that ensure adequate training of study staff and improved staffing on nights and weekends. Studies of parent responses in outpatient settings and additional inpatient settings will provide valuable information on the consent process from the child's and parent's perspectives. Further studies are needed to explore whether implementation of such strategies will result in improved recruitment for pediatric clinical trials.

  4. Do Implant Overdentures Improve Dietary Intake? A Randomized Clinical Trial

    PubMed Central

    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

  5. HIV vaccine trials: critical issues in informed consent.

    PubMed

    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.

  6. Research gaps identified during systematic reviews of clinical trials: glass-ionomer cements.

    PubMed

    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.

  7. The iodized salt programme in Bangalore, India provides adequate iodine intakes in pregnant women and more-than-adequate iodine intakes in their children.

    PubMed

    Jaiswal, Nidhi; Melse-Boonstra, Alida; Sharma, Surjeet Kaur; Srinivasan, Krishnamachari; Zimmermann, Michael B

    2015-02-01

    To compare the iodine status of pregnant women and their children who were sharing all meals in Bangalore, India. A cross-sectional study evaluating demographic characteristics, household salt iodine concentration and salt usage patterns, urinary iodine concentrations (UIC) in women and children, and maternal thyroid volume (ultrasound). Antenatal clinic of an urban tertiary-care hospital, which serves a low-income population. Healthy pregnant women in all trimesters, aged 18-35 years, who had healthy children aged 3-15 years. Median (range) iodine concentrations of household powdered and crystal salt were 55·9 (17·2-65·9) ppm and 18·9 (2·2-68·2) ppm, respectively. The contribution of iodine-containing supplements and multi-micronutrient powders to iodine intake in the families was negligible. Adequately iodized salt, together with small amounts of iodine in local foods, were providing adequate iodine during pregnancy: (i) the overall median (range) UIC in women was 172 (5-1024) µg/l; (ii) the median UIC was >150 µg/l in all trimesters; and (iii) thyroid size was not significantly different across trimesters. At the same time, the median (range) UIC in children was 220 (10-782) µg/l, indicating more-than-adequate iodine intake at this age. Median UIC was significantly higher in children than in their mothers (P=0·008). In this selected urban population of southern India, the iodized salt programme provides adequate iodine to women throughout pregnancy, at the expense of higher iodine intake in their children. Thus we suggest that the current cut-off for median UIC in children indicating more-than-adequate intake, recommended by the WHO/UNICEF/International Council for the Control of Iodine Deficiency Disorders may, need to be reconsidered.

  8. Stem Cell Trials for Cardiovascular Medicine: Ethical Rationale

    PubMed Central

    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

  9. Protocol for a multicentred randomised controlled trial investigating the use of personalised golimumab dosing tailored to inflammatory load in ulcerative colitis: the GOAL-ARC study (GLM dose Optimisation to Adequate Levels to Achieve Response in Colitis) led by the INITIAtive group (NCT 0268772)

    PubMed Central

    Sheridan, Juliette; Coe, Carol Ann; Doran, Peter; Egan, Laurence; Cullen, Garret; Kevans, David; Leyden, Jan; Galligan, Marie; O’Toole, Aoibhlinn; McCarthy, Jane; Doherty, Glen

    2018-01-01

    Introduction Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD), often leading to an impaired quality of life in affected patients. Current treatment modalities include antitumour necrosis factor (anti-TNF) monoclonal antibodies (mABs) including infliximab, adalimumab and golimumab (GLM). Several recent retrospective and prospective studies have demonstrated that fixed dosing schedules of anti-TNF agents often fails to consistently achieve adequate circulating therapeutic drug levels (DL) with consequent risk of immunogenicity treatment failure and potential risk of hospitalisation and colectomy in patients with UC. The design of GLM dose Optimisation to Adequate Levels to Achieve Response in Colitis aims to address the impact of dose escalation of GLM immediately following induction and during the subsequent maintenance phase in response to suboptimal DL or persisting inflammatory burden as represented by raised faecal calprotectin (FCP). Aim The primary aim of the study is to ascertain if monitoring of FCP and DL of GLM to guide dose optimisation (during maintenance) improves rates of patient continuous clinical response and reduces disease activity in UC. Methods and analysis A randomised, multicentred two-arm trial studying the effect of dose optimisation of GLM based on FCP and DL versus treatment as per SMPC. Eligible patients will be randomised in a 1:1 ratio to 1 of 2 treatment groups and shall be treated over a period of 46 weeks. Ethics and dissemination The study protocol was approved by the Research Ethics committee of St. Vincent’s University Hospital. The results will be published in a peer-reviewed journal and shared with the worldwide medical community. Trial registration numbers EudraCT number: 2015-004724-62; Clinicaltrials.gov Identifier: NCT0268772; Pre-results. PMID:29379609

  10. Children’s Oxygen Administration Strategies Trial (COAST):  A randomised controlled trial of high flow versus oxygen versus control in African children with severe pneumonia

    PubMed Central

    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

  11. Comparison of rheumatoid arthritis clinical trial outcome measures: a simulation study.

    PubMed

    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

  12. Adequate nutrient intake can reduce cardiovascular disease risk in African Americans.

    PubMed

    Reusser, Molly E; DiRienzo, Douglas B; Miller, Gregory D; McCarron, David A

    2003-03-01

    Cardiovascular disease kills nearly as many Americans each year as the next seven leading causes of death combined. The prevalence of cardiovascular disease and most of its associated risk factors is markedly higher and increasing more rapidly among African Americans than in any other racial or ethnic group. Improving these statistics may be simply a matter of improving diet quality. In recent years, a substantial and growing body of evidence has revealed that dietary patterns complete in all food groups, including nutrient-rich dairy products, are essential for preventing and reducing cardiovascular disease and the conditions that contribute to it. Several cardiovascular risk factors, including hypertension, insulin resistance syndrome, and obesity, have been shown to be positively influenced by dietary patterns that include adequate intake of dairy products. The benefits of nutrient-rich dietary patterns have been specifically tested in randomized, controlled trials emphasizing African American populations. These studies demonstrated proportionally greater benefits for African Americans without evidence of adverse effects such as symptoms of lactose intolerance. As currently promoted for the prevention of certain cancers and osteoporosis, regular consumption of diets that meet recommended nutrient intake levels might also be the most effective approach for reducing cardiovascular disease risk in African Americans.

  13. [Ethical principles of clinical trials in minors].

    PubMed

    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.

  14. Initial non-operative management of uncomplicated appendicitis in children: a protocol for a multicentre randomised controlled trial (APAC trial)

    PubMed Central

    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

  15. Money and morals: ending clinical trials for financial reasons.

    PubMed

    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.

  16. Temporal trends in receipt of adequate lymphadenectomy in bladder cancer 1988 to 2010.

    PubMed

    Cole, Alexander P; Dalela, Deepansh; Hanske, Julian; Mullane, Stephanie A; Choueiri, Toni K; Meyer, Christian P; Nguyen, Paul L; Menon, Mani; Kibel, Adam S; Preston, Mark A; Bellmunt, Joaquim; Trinh, Quoc-Dien

    2015-12-01

    The importance of pelvic lymphadenectomy (LND) for diagnostic and therapeutic purposes at the time of radical cystectomy (RC) for bladder cancer is well documented. Although some debate remains on the optimal number of lymph nodes removed, 10 nodes has been proposed as constituting an adequate LND. We used data from the Surveillance, Epidemiology, and End Results database to examine predictors and temporal trends in the receipt of an adequate LND at the time of RC for bladder cancer. Within the Surveillance, Epidemiology, and End Results database, we extracted data on all patients with nonmetastatic bladder cancer receiving RC in the years 1988 to 2010. First, we assess the proportion of individuals undergoing RC who received an adequate LND (≥10 nodes removed) over time. Second, we calculate odds ratios (ORs) of receiving an adequate LND using logistic regression modeling to compare study periods. Covariates included sex, race, age, region, tumor stage, urban vs. rural location, and insurance status. Among the 5,696 individuals receiving RC during the years 1988 to 2010, 2,576 (45.2%) received an adequate LND. Over the study period, the proportion of individuals receiving an adequate LND increased from 26.4% to 61.3%. The odds of receiving an adequate LND increased over the study period; a patient undergoing RC in 2008 to 2010 was over 4-fold more likely to receive an adequate LND relative to a patient treated in 1988 to 1991 (OR = 4.63, 95% CI: 3.32-6.45). In addition to time of surgery, tumor stage had a positive association with receipt of adequate LND (OR = 1.49 for stage IV [T4 N1 or N0] vs. stage I [T1 or Tis], 95% CI: 1.22-1.82). Age, sex, marital status, and race were not significant predictors of adequate LND. Adequacy of pelvic LND remains an important measure of surgical quality in bladder cancer. Our data show that over the years 1988 to 2010, the likelihood of receiving an adequate LND has increased substantially; however, a substantial minority of

  17. Can exercise improve self esteem in children and young people? A systematic review of randomised controlled trials

    PubMed Central

    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

  18. Region 8: Colorado Adequate Letter (10/29/2001)

    EPA Pesticide Factsheets

    This letter from EPA to Colorado Department of Public Health and Environment determined Denvers' particulate matter (PM10) maintenance plan for Motor Vehicle Emissions Budgets adequate for transportation conformity purposes.

  19. Health literacy and usability of clinical trial search engines.

    PubMed

    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.

  20. [Evaluation of the efficacy of powered and manual toothbrushes in preventing oral diseases (Systematic review with meta-analysis)].

    PubMed

    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

  1. Impact of non-uniform correlation structure on sample size and power in multiple-period cluster randomised trials.

    PubMed

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

    2017-01-01

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

  2. Region 1: Connecticut Adequate Letter (6/14/2017)

    EPA Pesticide Factsheets

    Letter from Office of Ecosystem Protection to Connecticut Department of Energy & Environmental Protection determined submitted 2017 Motor Vehicle Emissions Budgets adequate for transportation conformity purposes, Greater Connecticut area. (March 20, 2017)

  3. Region 8: Utah Adequate Letter (6/10/2005)

    EPA Pesticide Factsheets

    This letter from EPA to Utah Department of Environmental Quality determined Salt Lake Citys' and Ogdens' Carbon Monoxide (CO) maintenance plan for Motor Vehicle Emissions Budgets adequate for transportation conformity purposes.

  4. Continued midazolam versus diphenhydramine in difficult-to-sedate patients: a randomized double-blind trial.

    PubMed

    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.

  5. Recent direct seeding trials in the pine region

    Treesearch

    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...

  6. Tramadol effects on physical performance and sustained attention during a 20-min indoor cycling time-trial: A randomised controlled trial.

    PubMed

    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.

  7. 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)

  8. 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.

  9. Adequate calcium intake during long periods improves bone mineral density in healthy children. Data from the Childhood Obesity Project.

    PubMed

    Closa-Monasterolo, Ricardo; Zaragoza-Jordana, Marta; Ferré, Natàlia; Luque, Veronica; Grote, Veit; Koletzko, Berthold; Verduci, Elvira; Vecchi, Fiammetta; Escribano, Joaquin

    2018-06-01

    Bone mineralization can be influenced by genetic factors, hormonal status, nutrition, physical activity and body composition. The association of higher calcium (Ca) intake or Ca supplementation with better bone mineral density (BMD) remains controversial. Furthermore, it has been speculated that maintaining long-term adequate Ca intake rather than having a brief supplementation period is more effective. The aim of the study was to prospectively analyse the influence of adequate Ca intake on BMD at 7 years of age in European children. Data from the Childhood Obesity Project were analysed in a prospective longitudinal cohort trial. Dietary intake was recorded using 3-day food records at 4, 5 and 6 years of age. The probability of adequate intake (PA) of Ca was calculated following the American Institute of Medicine guidelines for individual assessments, with FAO, WHO and United Nations University joint expert consultation dietary recommendations. Children were categorised as having high Ca PA (PA >95%) or not (PA <95%). At 7 years, whole body (WB) and lumbar spine (LS) BMD were measured in the Spanish subsample by dual-energy x-ray absorptiometry. Internal BMD z-scores were calculated; BMD below -1 z-score were considered to indicate osteopenia, and BMD z-scores below -2, "low bone mineral density for age". BMD was measured in 179 children. Ca intake at 6 years was positively correlated with LS BMD at 7 years (R = 0.205, p = 0.030). A Ca increase of 100 mg/day explained 19.4% (p = 0.011) of the LS BMD z-score variation, modifying it by 0.089 (0.021, 0.157) units. Children with Ca PA >95% at 5 and 6 or from 4 to 6 years of age showed higher BMD z-scores at the LS and WB levels than children with Ca PA <95% (p < 0.001 and p < 0.05 for LS and WB BMD, respectively). Ca PA >95% maintained over 2 years explained 26.3% of the LS BMD z-score variation (p < 0.001), increasing it by 0.669 (0.202, 1.137). PA >95% maintained over 3 years explained 24.9% of the LS

  10. The importance of preservation of the ethical principle of equipoise in the design of clinical trials: relative impact of the methodological quality domains on the treatment effect in randomized controlled trials.

    PubMed

    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."

  11. Power Calculations for Moderators in Multi-Site Cluster Randomized Trials

    ERIC Educational Resources Information Center

    Spybrook, Jessaca; Kelcey, Ben; Dong, Nianbo

    2016-01-01

    Cluster randomized trials (CRTs), or studies in which intact groups of individuals are randomly assigned to a condition, are becoming more common in evaluation studies of educational programs. A specific type of CRT in which clusters are randomly assigned to treatment within blocks or sites, known as multisite cluster randomized trials (MSCRTs),…

  12. Region 9: Nevada Adequate Letter (3/30/2006)

    EPA Pesticide Factsheets

    This is a letter from Deborah Jordan, Director, to Leo M. Drozdoff regarding Nevada's motor vehicle emissions budgets in the 2005 Truckee Meadows CO Redesignation Request and Maintenance Plan are adequate for transportation conformity decisions.

  13. Region 6: Texas Adequate Letter (4/16/2010)

    EPA Pesticide Factsheets

    This letter from EPA to Texas Commission on Environmental Quality determined 2021 motor vehicle emission budgets for nitrogen oxides (NOx) and volatile organic compounds (VOCs) for Beaumont/Port Arthur area adequate for transportation conformity purposes

  14. Region 6: Texas Adequate Letter (6/21/17)

    EPA Pesticide Factsheets

    Letter from EPA approves Motor Vehicle Emissions Budgets contained in latest revisions to Houston/Galveston/Brazoria (HGB) 2008 8-hour Ozone State Implementation Plan, adequate for transportation conformity purposes and announced in the Federal Register.

  15. Transparency and public accessibility of clinical trial information in Croatia: how it affects patient participation in clinical trials.

    PubMed

    Šolić, Ivana; Stipčić, Ana; Pavličević, Ivančica; Marušić, Ana

    2017-06-15

    Despite increased visibility of clinical trials through international trial registries, patients often remain uninformed of their existence, especially if they do not have access to adequate information about clinical research, including the language of the information. The aim of this study was to describe the context for transparency of clinical trials in Croatia in relation to countries in Central and Eastern Europe, and to assess how informed Croatian patients are about clinical trials and their accessibility. We assessed the transparency of clinical trials from the data available in the public domain. We also conducted an anonymous survey on a convenience sample of 257 patients visiting two family medicine offices or an oncology department in south Croatia, and members of national patients' associations. Despite legal provisions for transparency of clinical trials in Croatia, they are still not sufficiently visible in the public domain. Among countries from Central and Eastern Europe, Croatia has the fewest number of registered trials in the EU Clinical Trials Registry. 66% of the patients in the survey were aware of the existence of clinical trials but only 15% were informed about possibilities of participating in a trial. Although 58% of the respondents were willing to try new treatments, only 6% actually participated in a clinical trial. Only 2% of the respondents were aware of publicly available trial registries. Our study demonstrates that there is low transparency of clinical trials in Croatia, and that Croatian patients are not fully aware of clinical trials and the possibilities of participating in them, despite reported availability of Internet resources and good communication with their physicians. There is a need for active policy measures to increase the awareness of and access to clinical trials to patients in Croatia, particularly in their own language.

  16. Region 8: Colorado Adequate Letter (1/20/2004)

    EPA Pesticide Factsheets

    This letter from EPA to Colorado Department of Public Health and Environment determined Greeleys' Carbon Monoxide (CO) maintenance plan for Motor Vehicle Emissions Budgets adequate for transportation conformity purposes and will be announced in the FR.

  17. Region 4: Tennessee Adequate Letter (9/30/2010)

    EPA Pesticide Factsheets

    This letter acknowledges that the EPA has reviewed Tennessee's Knoxville Area redesignation request and maintenace plan, as well as the motor vehicle emissions budgets (MVEBs) and have determined that these MVEBs are adequate for transportation conformity

  18. Region 9: California Adequate Letter (7/14/2017)

    EPA Pesticide Factsheets

    EPA approves California Air Resources Board Motor Vehicle Emissions Budgets in San Joaquin Valley Unified Air Pollution Control Districts 2016 Plan for 2008 8-Hour Ozone Standard adequate for transportation conformity purposes announced in Federal Register

  19. Region 9: Arizona Adequate Letter (10/14/2003)

    EPA Pesticide Factsheets

    This is a letter from Jack P. Broadben,. Director, to Nancy Wrona and Dennis Smith informing them that Maricopa County's motor vehicle emissions budgets in the 2003 MAGCO Maintenance Plan are adequate for transportation conformity purposes.

  20. Implementation Considerations for Multisite Clinical Trials with Cognitive Neuroscience Tasks

    PubMed Central

    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

  1. Recruitment of black and Latina women to a randomized controlled trial.

    PubMed

    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.

  2. Progression-free survival as primary endpoint in randomized clinical trials of targeted agents for advanced renal cell carcinoma. Correlation with overall survival, benchmarking and power analysis.

    PubMed

    Bria, Emilio; Massari, Francesco; Maines, Francesca; Pilotto, Sara; Bonomi, Maria; Porta, Camillo; Bracarda, Sergio; Heng, Daniel; Santini, Daniele; Sperduti, Isabella; Giannarelli, Diana; Cognetti, Francesco; Tortora, Giampaolo; Milella, Michele

    2015-01-01

    A correlation, power and benchmarking analysis between progression-free and overall survival (PFS, OS) of randomized trials with targeted agents or immunotherapy for advanced renal cell carcinoma (RCC) was performed to provide a practical tool for clinical trial design. For 1st-line of treatment, a significant correlation was observed between 6-month PFS and 12-month OS, between 3-month PFS and 9-month OS and between the distributions of the cumulative PFS and OS estimates. According to the regression equation derived for 1st-line targeted agents, 7859, 2873, 712, and 190 patients would be required to determine a 3%, 5%, 10% and 20% PFS advantage at 6 months, corresponding to an absolute increase in 12-month OS rates of 2%, 3%, 6% and 11%, respectively. These data support PFS as a reliable endpoint for advanced RCC receiving up-front therapies. Benchmarking and power analyses, on the basis of the updated survival expectations, may represent practical tools for future trial' design. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

    PubMed

    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.

  4. Study Design and Rationale for the Phase 3 Clinical Development Program of Enobosarm, a Selective Androgen Receptor Modulator, for the Prevention and Treatment of Muscle Wasting in Cancer Patients (POWER Trials).

    PubMed

    Crawford, Jeffrey; Prado, Carla M M; Johnston, Mary Ann; Gralla, Richard J; Taylor, Ryan P; Hancock, Michael L; Dalton, James T

    2016-06-01

    Muscle wasting in cancer is a common and often occult condition that can occur prior to overt signs of weight loss and before a clinical diagnosis of cachexia can be made. Muscle wasting in cancer is an important and independent predictor of progressive functional impairment, decreased quality of life, and increased mortality. Although several therapeutic agents are currently in development for the treatment of muscle wasting or cachexia in cancer, the majority of these agents do not directly inhibit muscle loss. Selective androgen receptor modulators (SARMs) have the potential to increase lean body mass (LBM) and hence muscle mass, without the untoward side effects seen with traditional anabolic agents. Enobosarm, a nonsteroidal SARM, is an agent in clinical development for prevention and treatment of muscle wasting in patients with cancer (POWER 1 and 2 trials). The POWER trials are two identically designed randomized, double-blind, placebo-controlled, multicenter, and multinational phase 3 trials to assess the efficacy of enobosarm for the prevention and treatment of muscle wasting in subjects initiating first-line chemotherapy for non-small-cell lung cancer (NSCLC). To assess enobosarm's effect on both prevention and treatment of muscle wasting, no minimum weight loss is required. These pivotal trials have pioneered the methodological and regulatory fields exploring a therapeutic agent for cancer-associated muscle wasting, a process hereby described. In each POWER trial, subjects will receive placebo (n = 150) or enobosarm 3 mg (n = 150) orally once daily for 147 days. Physical function, assessed as stair climb power (SCP), and LBM, assessed by dual-energy X-ray absorptiometry (DXA), are the co-primary efficacy endpoints in both trials assessed at day 84. Based on extensive feedback from the US Food and Drug Administration (FDA), the co-primary endpoints will be analyzed as a responder analysis. To be considered a physical function responder, a

  5. Improving the power of clinical trials of rheumatoid arthritis by using data on continuous scales when analysing response rates: an application of the augmented binary method

    PubMed Central

    Jenkins, Martin

    2016-01-01

    Objective. In clinical trials of RA, it is common to assess effectiveness using end points based upon dichotomized continuous measures of disease activity, which classify patients as responders or non-responders. Although dichotomization generally loses statistical power, there are good clinical reasons to use these end points; for example, to allow for patients receiving rescue therapy to be assigned as non-responders. We adopt a statistical technique called the augmented binary method to make better use of the information provided by these continuous measures and account for how close patients were to being responders. Methods. We adapted the augmented binary method for use in RA clinical trials. We used a previously published randomized controlled trial (Oral SyK Inhibition in Rheumatoid Arthritis-1) to assess its performance in comparison to a standard method treating patients purely as responders or non-responders. The power and error rate were investigated by sampling from this study. Results. The augmented binary method reached similar conclusions to standard analysis methods but was able to estimate the difference in response rates to a higher degree of precision. Results suggested that CI widths for ACR responder end points could be reduced by at least 15%, which could equate to reducing the sample size of a study by 29% to achieve the same statistical power. For other end points, the gain was even higher. Type I error rates were not inflated. Conclusion. The augmented binary method shows considerable promise for RA trials, making more efficient use of patient data whilst still reporting outcomes in terms of recognized response end points. PMID:27338084

  6. POWERS forID: Personalized Online Weight and Exercise Response System for Individuals with Intellectual Disability: study protocol for a randomized controlled trial.

    PubMed

    Neumeier, William H; Guerra, Nichole; Thirumalai, Mohanraj; Geer, Betty; Ervin, David; Rimmer, James H

    2017-10-23

    Intellectual disability (ID) is characterized by limitations in intellectual functioning and adaptive behavior. Adults with ID exhibit higher rates of obesity and poorer health status compared to the general population. Continuity of care and barriers to health-related activities may contribute to the poorer health status observed in this population. To address this problem, a tailored weight management online health information and communication technology platform, known as POWERS forID , was developed and is being tested to determine if this delivery mechanism can improve weight maintenance/weight loss in adults with ID. Obese adults with mild-to-moderate ID (n = 70) are randomized to the POWERS forID intervention or control group for a 24-week trial. Each group undergoes an assessment that includes body weight, waist circumference, and percent body fat at baseline and at weeks 6, 12, and 24. Physical activity barriers, healthy eating barriers, food frequency, and psychosocial wellbeing are measured at baseline and at weeks 12 and 24. Blood lipids are assessed at baseline and 24 weeks. Participants randomized to POWERS forID receive access to the POWERS forID website and calls from a health coach (weekly during weeks 1-12, biweekly during weeks 13-24). The health coach employs motivational interviewing techniques adapted for individuals with ID to promote behavior change. Participants randomized to the control group receive standard clinical weight-loss care. Differences in weight, waist circumference, blood lipids, percent body fat, and psychosocial self-report will be assessed. Barriers and facilitators of implementation as well as perception of study outcomes will be conducted via qualitative analysis. POWERS forID is a novel information and communication technology platform designed to address health needs for adults with ID. This article describes the development and components of POWERS forID . The overall aim is to assess usability and feasibility of

  7. Region 5: Wisconsin Adequate Letter (4/16/2015)

    EPA Pesticide Factsheets

    This March 13, 2015 letter from EPA approves Wisconsins Kenosha and Sheboygan counties Early Progress Plan for year 2015 Motor Vehicle Emissions Budgets (MVEBs) for VOC and NOx finding them adequate for transportation conformity purposes and will be announ

  8. Multicenter clinical trials in sepsis: understanding the big picture and building a successful operation at your hospital.

    PubMed

    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.

  9. Region 8: Colorado Adequate Letter (8/17/2011)

    EPA Pesticide Factsheets

    This March 4, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Greeley, CO second 10 year Limited Maintenance Plan (LMP) adequate for transportation conformity

  10. Region 8: Colorado Adequate Letter (6/11/2012)

    EPA Pesticide Factsheets

    This August 9, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Fort Collins, CO second 10 year Limited Maintenance Plan (LMP) adequate for transportation

  11. Using Multitheory Model of Health Behavior Change to Predict Adequate Sleep Behavior.

    PubMed

    Knowlden, Adam P; Sharma, Manoj; Nahar, Vinayak K

    The purpose of this article was to use the multitheory model of health behavior change in predicting adequate sleep behavior in college students. A valid and reliable survey was administered in a cross-sectional design (n = 151). For initiation of adequate sleep behavior, the construct of behavioral confidence (P < .001) was found to be significant and accounted for 24.4% of the variance. For sustenance of adequate sleep behavior, changes in social environment (P < .02), emotional transformation (P < .001), and practice for change (P < .001) were significant and accounted for 34.2% of the variance.

  12. Intermediate addition multifocals provide safe stair ambulation with adequate 'short-term' reading.

    PubMed

    Elliott, David B; Hotchkiss, John; Scally, Andrew J; Foster, Richard; Buckley, John G

    2016-01-01

    A recent randomised controlled trial indicated that providing long-term multifocal wearers with a pair of distance single-vision spectacles for use outside the home reduced falls risk in active older people. However, it also found that participants disliked continually switching between using two pairs of glasses and adherence to the intervention was poor. In this study we determined whether intermediate addition multifocals (which could be worn most of the time inside and outside the home and thus avoid continual switching) could provide similar gait safety on stairs to distance single vision spectacles whilst also providing adequate 'short-term' reading and near vision. Fourteen healthy long-term multifocal wearers completed stair ascent and descent trials over a 3-step staircase wearing intermediate and full addition bifocals and progression-addition lenses (PALs) and single-vision distance spectacles. Gait safety/caution was assessed using foot clearance measurements (toe on ascent, heel on descent) over the step edges and ascent and descent duration. Binocular near visual acuity, critical print size and reading speed were measured using Bailey-Lovie near charts and MNRead charts at 40 cm. Gait safety/caution measures were worse with full addition bifocals and PALs compared to intermediate bifocals and PALs. The intermediate PALs provided similar gait ascent/descent measures to those with distance single-vision spectacles. The intermediate addition PALs also provided good reading ability: Near word acuity and MNRead critical print size were better with the intermediate addition PALs than with the single-vision lenses (p < 0.0001), with a mean near visual acuity of 0.24 ± 0.13 logMAR (~N5.5) which is satisfactory for most near vision tasks when performed for a short period of time. The better ability to 'spot read' with the intermediate addition PALs compared to single-vision spectacles suggests that elderly individuals might better comply with the use of

  13. Trials with errors--preserving the integrity of clinical trials.

    PubMed

    Guyer, R L

    2000-01-01

    The crucial final test of medical research is the clinical trial, which determines whether a drug or discovery really is an effective therapy. All people who participate in clinical trials--researchers, sponsors, volunteers, analysts, reviewers, overseers, others--have opportunities to strengthen or weaken the integrity of the trial system by their behavior. Medical research is now officially married to business, and "profitable" connotes something different to each partner. Only if research and business can profit in parallel will the alliance succeed. Every person who is involved in the medical research business faces temptations and must choose how to react. Each has power and must choose how to wield it. Several centuries before this marriage, the Englishman Izaak Walton noted that "Health is...a blessing that money cannot buy."

  14. Adjuvant radiation trials for high-risk breast cancer patients: adequacy of lymphadenectomy.

    PubMed

    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

  15. The challenges and opportunities of conducting a clinical trial in a low resource setting: the case of the Cameroon mobile phone SMS (CAMPS) trial, an investigator initiated trial.

    PubMed

    Mbuagbaw, Lawrence; Thabane, Lehana; Ongolo-Zogo, Pierre; Lang, Trudie

    2011-06-09

    Conducting clinical trials in developing countries often presents significant ethical, organisational, cultural and infrastructural challenges to researchers, pharmaceutical companies, sponsors and regulatory bodies. Globally, these regions are under-represented in research, yet this population stands to gain more from research in these settings as the burdens on health are greater than those in developed resourceful countries. However, developing countries also offer an attractive setting for clinical trials because they often have larger treatment naive populations with higher incidence rates of disease and more advanced stages. These factors can present a reduction in costs and time required to recruit patients. So, balance needs to be found where research can be encouraged and supported in order to bring maximum public health benefits to these communities. The difficulties with such trials arise from problems with obtaining valid informed consent, ethical compensation mechanisms for extremely poor populations, poor health infrastructure and considerable socio-economic and cultural divides. Ethical concerns with trials in developing countries have received attention, even though many other non-ethical issues may arise. Local investigator initiated trials also face a variety of difficulties that have not been adequately reported in literature. This paper uses the example of the Cameroon Mobile Phone SMS trial to describe in detail, the specific difficulties encountered in an investigator-initiated trial in a developing country. It highlights administrative, ethical, financial and staff related issues, proposes solutions and gives a list of additional documentation to ease the organisational process.

  16. Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?

    PubMed

    Glanville, Julie M; Duffy, Steven; McCool, Rachael; Varley, Danielle

    2014-07-01

    Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication. The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers. A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources. On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews. Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces. For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.

  17. Generalizability of findings from randomized controlled trials: application to the National Institute of Drug Abuse Clinical Trials Network.

    PubMed

    Susukida, Ryoko; Crum, Rosa M; Ebnesajjad, Cyrus; Stuart, Elizabeth A; Mojtabai, Ramin

    2017-07-01

    To compare randomized controlled trial (RCT) sample treatment effects with the population effects of substance use disorder (SUD) treatment. Statistical weighting was used to re-compute the effects from 10 RCTs such that the participants in the trials had characteristics that resembled those of patients in the target populations. Multi-site RCTs and usual SUD treatment settings in the United States. A total of 3592 patients in 10 RCTs and 1 602 226 patients from usual SUD treatment settings between 2001 and 2009. Three outcomes of SUD treatment were examined: retention, urine toxicology and abstinence. We weighted the RCT sample treatment effects using propensity scores representing the conditional probability of participating in RCTs. Weighting the samples changed the significance of estimated sample treatment effects. Most commonly, positive effects of trials became statistically non-significant after weighting (three trials for retention and urine toxicology and one trial for abstinence); also, non-significant effects became significantly positive (one trial for abstinence) and significantly negative effects became non-significant (two trials for abstinence). There was suggestive evidence of treatment effect heterogeneity in subgroups that are under- or over-represented in the trials, some of which were consistent with the differences in average treatment effects between weighted and unweighted results. The findings of randomized controlled trials (RCTs) for substance use disorder treatment do not appear to be directly generalizable to target populations when the RCT samples do not reflect adequately the target populations and there is treatment effect heterogeneity across patient subgroups. © 2017 Society for the Study of Addiction.

  18. Region 8: Colorado Adequate Letter (6/11/2012)

    EPA Pesticide Factsheets

    This August 11, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Aspen PM10 maintenance plan and the 2023 motor vehicle emissions budget (MVEB) adequate

  19. Region 9: Arizona Adequate Letter (11/1/2001)

    EPA Pesticide Factsheets

    This is a letter from Jack P. Broadbent, Director, Air Division to Nancy Wrona and James Bourney informing them of the adequacy of Revised MAG 1999 Serious Area Carbon Monoxide Plan and that the MAG CO Plan is adequate for Maricopa County.

  20. Region 9: California Adequate Letter (1/22/2018)

    EPA Pesticide Factsheets

    This December 19, 2017 letter form EPA, finding adequate certain motor vehicle emissions budgets for the 2006 fine particulate matter (PM2.5) National Ambient Air Quality Standars in the Final 2016 Air Quality Managemnet Plan for the South Coast area (2016

  1. Non-penetrating sham needle, is it an adequate sham control in acupuncture research?

    PubMed

    Lee, Hyangsook; Bang, Heejung; Kim, Youngjin; Park, Jongbae; Lee, Sangjae; Lee, Hyejung; Park, Hi-Joon

    2011-01-01

    This study aimed to determine whether a non-penetrating sham needle can serve as an adequate sham control. We conducted a randomised, subject-blind, sham-controlled trial in both acupuncture-naïve and experienced healthy volunteers. Participants were randomly allocated to receive either real acupuncture (n=39) or non-penetrating sham acupuncture (n=40) on the hand (LI4), abdomen (CV12) and leg (ST36). The procedures were standardised and identical for both groups. Participants rated acupuncture sensations on a 10-point scale. A blinding index was calculated based on the participants' guesses on the type of acupuncture they had received (real, sham or do not know) for each acupuncture point. The association of knowledge about and experience in acupuncture with correct guessing was also examined. The subjects in both groups were similar with respect to age, gender, experience or knowledge about acupuncture. The sham needle tended to produce less penetration, pain and soreness only at LI4. Blinding appeared to be successfully achieved for ST36. Although 41% of participants in the real acupuncture group made correct guesses for LI4, 31% guessed incorrectly for CV12, beyond chance level. People with more experience and knowledge about acupuncture were more likely to correctly guess the type of needle they received at ST36 only, compared to that at the other points. A non-penetrating sham needle may successfully blind participants and thus, may be a credible sham control. However, the small sample size, the different needle sensations, and the degree and direction of unblinding across acupuncture points warrant further studies in Korea as well as other countries to confirm our finding. Our results also justify the incorporation of formal testing of the use of sham controls in clinical trials of acupuncture. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Inappropriate oral formulations and information in paediatric trials.

    PubMed

    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.

  3. HPTN 071 (PopART): rationale and design of a cluster-randomised trial of the population impact of an HIV combination prevention intervention including universal testing and treatment - a study protocol for a cluster randomised trial.

    PubMed

    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

  4. 21 CFR 886.1405 - Ophthalmic trial lens set.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens set. 886.1405 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1405 Ophthalmic trial lens set. (a) Identification. An ophthalmic trial lens set is a device that is a set of lenses of various dioptric powers...

  5. Effectiveness of a Wheelchair Skills Training Program for Powered Wheelchair Users: A Randomized Controlled Trial

    PubMed Central

    Kirby, R. Lee; Miller, William C.; Routhier, Francois; Demers, Louise; Mihailidis, Alex; Polgar, Jan Miller; Rushton, Paula W.; Titus, Laura; Smith, Cher; McAllister, Mike; Theriault, Chris; Thompson, Kara; Sawatzky, Bonita

    2015-01-01

    Objectives To test the hypothesis that powered wheelchair users who receive the Wheelchair Skills Training Program (WSTP) improve their wheelchair skills in comparison with a Control group that receives standard care. Our secondary objectives were to assess goal achievement, satisfaction with training, retention, injury rate, confidence with wheelchair use and participation. Design Randomized controlled trial (RCT). Setting Rehabilitation centers and communities. Participants 116 powered wheelchair users. Intervention Five 30-minute WSTP training sessions. Main Outcome Measures Assessments were done at baseline (T1), post-training (T2) and 3 months post-training (T3) using the Wheelchair Skills Test Questionnaire (WST-Q 4.1), Goal Attainment Score (GAS), Satisfaction Questionnaire, Injury Rate, Wheelchair Use Confidence Scale for Power Wheelchair Users (WheelCon) and Life Space Assessment (LSA). Results There was no significant T2-T1 difference between the groups for WST-Q capacity scores (p = 0.600) but the difference for WST-Q performance scores was significant (p = 0.016) with a relative (T2/T1 x 100%) improvement of the median score for the Intervention group of 10.8%. The mean (SD) GAS for the Intervention group after training was 92.8% (11.4) and satisfaction with training was high. The WST-Q gain was not retained at T3. There was no clinically significant difference between the groups in injury rate and no statistically significant differences in WheelCon or LSA scores at T3. Conclusions Powered wheelchair users who receive formal wheelchair skills training demonstrate modest transient post-training improvements in their WST-Q performance scores, they have substantial improvements on individualized goals and they are positive about training. PMID:26232684

  6. Conditional power and predictive power based on right censored data with supplementary auxiliary information.

    PubMed

    Sun, Libo; Wan, Ying

    2018-04-22

    Conditional power and predictive power provide estimates of the probability of success at the end of the trial based on the information from the interim analysis. The observed value of the time to event endpoint at the interim analysis could be biased for the true treatment effect due to early censoring, leading to a biased estimate of conditional power and predictive power. In such cases, the estimates and inference for this right censored primary endpoint are enhanced by incorporating a fully observed auxiliary variable. We assume a bivariate normal distribution of the transformed primary variable and a correlated auxiliary variable. Simulation studies are conducted that not only shows enhanced conditional power and predictive power but also can provide the framework for a more efficient futility interim analysis in terms of an improved accuracy in estimator, a smaller inflation in type II error and an optimal timing for such analysis. We also illustrated the new approach by a real clinical trial example. Copyright © 2018 John Wiley & Sons, Ltd.

  7. Precise ablation of dental hard tissues with ultra-short pulsed lasers. Preliminary exploratory investigation on adequate laser parameters.

    PubMed

    Bello-Silva, Marina Stella; Wehner, Martin; Eduardo, Carlos de Paula; Lampert, Friedrich; Poprawe, Reinhart; Hermans, Martin; Esteves-Oliveira, Marcella

    2013-01-01

    This study aimed to evaluate the possibility of introducing ultra-short pulsed lasers (USPL) in restorative dentistry by maintaining the well-known benefits of lasers for caries removal, but also overcoming disadvantages, such as thermal damage of irradiated substrate. USPL ablation of dental hard tissues was investigated in two phases. Phase 1--different wavelengths (355, 532, 1,045, and 1,064 nm), pulse durations (picoseconds and femtoseconds) and irradiation parameters (scanning speed, output power, and pulse repetition rate) were assessed for enamel and dentin. Ablation rate was determined, and the temperature increase measured in real time. Phase 2--the most favorable laser parameters were evaluated to correlate temperature increase to ablation rate and ablation efficiency. The influence of cooling methods (air, air-water spray) on ablation process was further analyzed. All parameters tested provided precise and selective tissue ablation. For all lasers, faster scanning speeds resulted in better interaction and reduced temperature increase. The most adequate results were observed for the 1064-nm ps-laser and the 1045-nm fs-laser. Forced cooling caused moderate changes in temperature increase, but reduced ablation, being considered unnecessary during irradiation with USPL. For dentin, the correlation between temperature increase and ablation efficiency was satisfactory for both pulse durations, while for enamel, the best correlation was observed for fs-laser, independently of the power used. USPL may be suitable for cavity preparation in dentin and enamel, since effective ablation and low temperature increase were observed. If adequate laser parameters are selected, this technique seems to be promising for promoting the laser-assisted, minimally invasive approach.

  8. Power and efficiency of insect flight muscle.

    PubMed

    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%.

  9. 13 CFR 107.200 - Adequate capital for Licensees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... operate actively in accordance with your Articles and within the context of your business plan, as... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Adequate capital for Licensees. 107.200 Section 107.200 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS...

  10. An evaluation of the completeness of safety reporting in reports of complementary and alternative medicine trials

    PubMed Central

    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

  11. 42 CFR 417.568 - Adequate financial records, statistical data, and cost finding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ORGANIZATIONS, COMPETITIVE MEDICAL PLANS, AND HEALTH CARE PREPAYMENT PLANS Medicare Payment: Cost Basis § 417... health care industry. (b) Provision of data. (1) The HMO or CMP must provide adequate cost and... 42 Public Health 3 2012-10-01 2012-10-01 false Adequate financial records, statistical data, and...

  12. 42 CFR 417.568 - Adequate financial records, statistical data, and cost finding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., COMPETITIVE MEDICAL PLANS, AND HEALTH CARE PREPAYMENT PLANS Medicare Payment: Cost Basis § 417.568 Adequate... definitions and accounting, statistics, and reporting practices that are widely accepted in the health care... 42 Public Health 3 2010-10-01 2010-10-01 false Adequate financial records, statistical data, and...

  13. 42 CFR 417.568 - Adequate financial records, statistical data, and cost finding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., COMPETITIVE MEDICAL PLANS, AND HEALTH CARE PREPAYMENT PLANS Medicare Payment: Cost Basis § 417.568 Adequate... definitions and accounting, statistics, and reporting practices that are widely accepted in the health care... 42 Public Health 3 2011-10-01 2011-10-01 false Adequate financial records, statistical data, and...

  14. Adjusting for multiple prognostic factors in the analysis of randomised trials

    PubMed Central

    2013-01-01

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

  15. Child malnutrition and mortality among families not utilizing adequately iodized salt in Indonesia.

    PubMed

    Semba, Richard D; de Pee, Saskia; Hess, Sonja Y; Sun, Kai; Sari, Mayang; Bloem, Martin W

    2008-02-01

    Salt iodization is the main strategy for reducing iodine deficiency disorders worldwide. Characteristics of families not using iodized salt need to be known to expand coverage. The objective was to determine whether families who do not use iodized salt have a higher prevalence of child malnutrition and mortality and to identify factors associated with not using iodized salt. Use of adequately iodized salt (>or =30 ppm), measured by rapid test kits, was assessed between January 1999 and September 2003 in 145 522 and 445 546 families in urban slums and rural areas, respectively, in Indonesia. Adequately iodized salt was used by 66.6% and 67.2% of families from urban slums and rural areas, respectively. Among families who used adequately iodized salt, mortality in neonates, infants, and children aged <5 y was 3.3% compared with 4.2%, 5.5% compared with 7.1%, and 6.9% compared with 9.1%, respectively (P < 0.0001 for all), in urban slums; among families who did not use adequately iodized salt, the respective values were 4.2% compared with 6.3%, 7.1% compared with 11.2%, and 8.5% compared with 13.3% (P < 0.0001 for all) in rural areas. Families not using adequately iodized salt were more likely to have children who were stunted, underweight, and wasted. In multivariate analyses that controlled for potential confounders, low maternal education was the strongest factor associated with not using adequately iodized salt. In Indonesia, nonuse of adequately iodized salt is associated with a higher prevalence of child malnutrition and mortality in neonates, infants, and children aged <5 y. Stronger efforts are needed to expand salt iodization in Indonesia.

  16. Region 6: New Mexico Adequate Letter (8/21/2003)

    EPA Pesticide Factsheets

    This is a letter from Carl Edlund, Director, to Alfredo Santistevan regarding MVEB's contained in the latest revision to the Albuquerque Carbon Monoxide State Implementation Plan (SIP) are adequate for transportation conformity purposes.

  17. Region 10: Oregon Oakridge Adequate Letter (6/21/2017)

    EPA Pesticide Factsheets

    EPA approves motor vehicle emissions budget in the Oakridge-Westfir PM2.5 Attainment State Implementation Plan for the 2006 PM2.5 national ambient air quality standard, adequate for transportation conformity purposes.

  18. Understanding Your Adequate Yearly Progress (AYP), 2011-2012

    ERIC Educational Resources Information Center

    Missouri Department of Elementary and Secondary Education, 2011

    2011-01-01

    The "No Child Left Behind Act (NCLB) of 2001" requires all schools, districts/local education agencies (LEAs) and states to show that students are making Adequate Yearly Progress (AYP). NCLB requires states to establish targets in the following ways: (1) Annual Proficiency Target; (2) Attendance/Graduation Rates; and (3) Participation…

  19. Nurse-Led Programs to Facilitate Enrollment to Children's Oncology Group Cancer Control Trials.

    PubMed

    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.

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. Predictors for achieving adequate protein and energy intake in nursing home rehabilitation patients.

    PubMed

    van Zwienen-Pot, J I; Visser, M; Kruizenga, H M

    2018-07-01

    Adequate energy and protein intake could be essential for contributing significantly to the rehabilitations process. Data on the actual nutritional intake of older nursing home rehabilitation patients have not yet been investigated. To investigate the nutritional intake and predictors for achieving protein and energy requirements on the 14th day of admission in nursing home rehabilitation patients. Fifty-nine patients aged 65+ years newly admitted to nursing home rehabilitation wards were included. Data on potential variables were collected on admission. On the fourteenth day nutritional intake was assessed. Intake was considered 'adequate' if patients had achieved ≥ 1.2 g of protein/kg bodyweight and ≥ 85% of their energy needs according to Harris and Benedict + 30%. Multiple logistic regression analyses were performed to select predictors for adequate intake. Protein and energy intake was assessed in 79 patients [67% female, mean age 82 ± (SD) 8 years, BMI 25 ± 6 kg/m 2 ]. Mean energy intake was 1677 kcal (± 433) and mean protein intake was 68 g (± 20). Fourteen patients (18%) achieved an adequate protein and energy intake. Predictors for adequate intake were use of sip/tube feeding (OR = 7.7; 95% CI = 1.35-44.21), BMI (0.68; 0.53-0.87) and nausea (8.59; 1.42-52.01). Only 18% of older nursing home rehabilitation patients had an adequate protein and energy intake at 14 days after admission. Patients with higher BMI were less likely, while those using sip/tube feeding or feeling nauseous were more likely to achieve an adequate protein and energy intake.

  6. Assessing the Eligibility Criteria in Phase III Randomized Controlled Trials of Drug Therapy in Heart Failure With Preserved Ejection Fraction: The Critical Play-Off Between a "Pure" Patient Phenotype and the Generalizability of Trial Findings.

    PubMed

    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.

  7. A Mixed-Methods, Randomized, Controlled Feasibility Trial to Inform the Design of a Phase III Trial to Test the Effect of the Handheld Fan on Physical Activity and Carer Anxiety in Patients With Refractory Breathlessness.

    PubMed

    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.

  8. Selection and quantification of infection endpoints for trials of vaccines against intestinal helminths

    PubMed Central

    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

  9. Informed consent in surgical trials.

    PubMed

    Etchells, E

    1999-12-01

    All participants must provide a valid consent to surgical clinical trials. A valid consent requires patient capacity, adequate disclosure of information, and voluntariness. Capacity is the ability to understand information relevant to making a decision and to appreciate the reasonably foreseeable consequences of a decision or lack of decision. To protect vulnerable persons, an incapable person should not be enrolled in most clinical trials. The only exception is if the study can only be conducted on incapable persons. If the willing research participant is incapable, consent must be obtained from others through a process called substitute (or proxy) consent. Disclosure refers to the provision of relevant information to the patient and its comprehension by the patient. Most surgical trials carry more than minimal risks, so the requirement for careful disclosure of these risks to potential participants is generally stringent. Voluntariness refers to the freedom of a person to make a treatment decision. In specific circumstances related to emergency research, the requirement for consent may be waived. Waiver can be justified only if the delay required to obtain consent would prevent the research from occurring and only after prior consultation with from the "community" of potential research participants.

  10. 34 CFR 200.20 - Making adequate yearly progress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... adequate yearly progress. A school or LEA makes AYP if it complies with paragraph (c) and with either paragraph (a) or (b) of this section separately in reading/language arts and in mathematics. (a)(1) A school... school or LEA, respectively, meets or exceeds the State's other academic indicators under § 200.19. (2...

  11. 34 CFR 200.20 - Making adequate yearly progress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... adequate yearly progress. A school or LEA makes AYP if it complies with paragraph (c) and with either paragraph (a) or (b) of this section separately in reading/language arts and in mathematics. (a)(1) A school... school or LEA, respectively, meets or exceeds the State's other academic indicators under § 200.19. (2...

  12. 34 CFR 200.20 - Making adequate yearly progress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... adequate yearly progress. A school or LEA makes AYP if it complies with paragraph (c) and with either paragraph (a) or (b) of this section separately in reading/language arts and in mathematics. (a)(1) A school... school or LEA, respectively, meets or exceeds the State's other academic indicators under § 200.19. (2...

  13. 34 CFR 200.20 - Making adequate yearly progress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... adequate yearly progress. A school or LEA makes AYP if it complies with paragraph (c) and with either paragraph (a) or (b) of this section separately in reading/language arts and in mathematics. (a)(1) A school... school or LEA, respectively, meets or exceeds the State's other academic indicators under § 200.19. (2...

  14. Comparability and Reliability Considerations of Adequate Yearly Progress

    ERIC Educational Resources Information Center

    Maier, Kimberly S.; Maiti, Tapabrata; Dass, Sarat C.; Lim, Chae Young

    2012-01-01

    The purpose of this study is to develop an estimate of Adequate Yearly Progress (AYP) that will allow for reliable and valid comparisons among student subgroups, schools, and districts. A shrinkage-type estimator of AYP using the Bayesian framework is described. Using simulated data, the performance of the Bayes estimator will be compared to…

  15. 40 CFR 152.20 - Exemptions for pesticides adequately regulated by another Federal agency.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Exemptions for pesticides adequately... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Exemptions § 152.20 Exemptions for pesticides adequately regulated by another Federal agency. The pesticides...

  16. 40 CFR 152.20 - Exemptions for pesticides adequately regulated by another Federal agency.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Exemptions for pesticides adequately... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Exemptions § 152.20 Exemptions for pesticides adequately regulated by another Federal agency. The pesticides...

  17. 40 CFR 152.20 - Exemptions for pesticides adequately regulated by another Federal agency.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Exemptions for pesticides adequately... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Exemptions § 152.20 Exemptions for pesticides adequately regulated by another Federal agency. The pesticides...

  18. Isolated Power Generation System Using Permanent Magnet Synchronous Generator with Improved Power Quality

    NASA Astrophysics Data System (ADS)

    Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh

    2018-03-01

    This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.

  19. Isolated Power Generation System Using Permanent Magnet Synchronous Generator with Improved Power Quality

    NASA Astrophysics Data System (ADS)

    Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh

    2018-06-01

    This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.

  20. Rationale for the Assessment of Metoprolol in the Prevention of Vasovagal Syncope in Aging Subjects Trial (POST5).

    PubMed

    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.

  1. Region 1: New Hampshire Adequate Letter (8/12/2008)

    EPA Pesticide Factsheets

    This July 9, 2008 letter from EPA to the New Hampshire Department of Environmental Services, determined the 2009 Motor Vehicle Emissions Budgets (MVEBs) are adequate for transportation conformity purposes and will be announced in the Federal Register (FR).

  2. Region 6: Texas Austin Adequate Letter (11/23/2016)

    EPA Pesticide Factsheets

    EPA letter approves the Motor Vehicle Emissions Budgets contained in the latest revision to Dallas/Fort Worth 2008 8-hour Ozone State Implementation Plan, finding them adequate for transportation conformity purposes to be announced in the Federal Register.

  3. Region 1: New Hampshire Adequate Letter (5/29/2012)

    EPA Pesticide Factsheets

    This April 25, 2012 letter from EPA to the New Hampshire Department of Environmental Services, determined the 2008 and 2022 Motor Vehicle Emissions Budgets (MVEBs) are adequate for transportation conformity purposes and will be announced in the Federal Reg

  4. Region 5: Ohio Columbus Adequate Letter (8/23/2016)

    EPA Pesticide Factsheets

    Letter from EPA to State of Ohio determined the 2008 8-hour ozone standard plan for years 2020 and 2030 Motor Vehicle Emissions Budgets for volatile organic compounds and nitrogen oxides for Columbus area adequate for transportation conformity purposes.

  5. Inadequate safety reporting in pre-eclampsia trials: a systematic evaluation.

    PubMed

    Duffy, Jmn; Hirsch, M; Pealing, L; Showell, M; Khan, K S; Ziebland, S; McManus, R J

    2018-06-01

    Randomised trials and their syntheses in meta-analyses offer a unique opportunity to assess the frequency and severity of adverse reactions. To assess safety reporting in pre-eclampsia trials. Systematic search using bibliographic databases, including Cochrane Central Register of Controlled Trials, Embase, and MEDLINE, from inception to August 2017. Randomised trials evaluating anticonvulsant or antihypertensive medication for pre-eclampsia. Descriptive statistics appraising the adequacy of adverse reaction and toxicity reporting. We included 60 randomised trials. Six trials (10%) were registered with the International Clinical Trials Registry Platform, two registry records referred to adverse reactions, stating 'safety and toleration' and 'possible side effects' would be collected. Twenty-six trials (43%) stated the frequency of withdrawals within each study arm, and five trials (8%) adequately reported these withdrawals. Adverse reactions were inconsistently reported across eligible trials: 24 (40%) reported no serious adverse reactions and 36 (60%) reported no mild adverse reactions. The methods of definition or measurement of adverse reactions were infrequently reported within published trial reports. Pre-eclampsia trials regularly omit critical information related to safety. Despite the paucity of reporting, randomised trials collect an enormous amount of safety data. Developing and implementing a minimum data set could help to improve safety reporting, permitting a more balanced assessment of interventions by considering the trade-off between the benefits and harms. National Institute for Health Research (DRF-2014-07-051), UK; Maternity Forum, Royal Society of Medicine, UK. Developing @coreoutcomes could help to improve safety reporting in #preeclampsia trials. @NIHR_DC. © 2017 Royal College of Obstetricians and Gynaecologists.

  6. Simulations for designing and interpreting intervention trials in infectious diseases.

    PubMed

    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.

  7. 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…

  8. Region 8: Colorado Springs Adequate Letter (8/17/2011)

    EPA Pesticide Factsheets

    This March 3, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Colorado Springs, CO second 10 year Limited Maintenance Plan (LMP) adequate for transportation

  9. Minimum requirements for adequate nighttime conspicuity of highway signs

    DOT National Transportation Integrated Search

    1988-02-01

    A laboratory and field study were conducted to assess the minimum luminance levels of signs to ensure that they will be detected and identified at adequate distances under nighttime driving conditions. A total of 30 subjects participated in the field...

  10. Inferential Processing among Adequate and Struggling Adolescent Comprehenders and Relations to Reading Comprehension

    PubMed Central

    Barth, Amy E.; Barnes, Marcia; Francis, David J.; Vaughn, Sharon; York, Mary

    2015-01-01

    Separate mixed model analyses of variance (ANOVA) were conducted to examine the effect of textual distance on the accuracy and speed of text consistency judgments among adequate and struggling comprehenders across grades 6–12 (n = 1203). Multiple regressions examined whether accuracy in text consistency judgments uniquely accounted for variance in comprehension. Results suggest that there is considerable growth across the middle and high school years, particularly for adequate comprehenders in those text integration processes that maintain local coherence. Accuracy in text consistency judgments accounted for significant unique variance for passage-level, but not sentence-level comprehension, particularly for adequate comprehenders. PMID:26166946

  11. Improved Endpoints for Cancer Immunotherapy Trials

    PubMed Central

    Eggermont, Alexander M. M.; Janetzki, Sylvia; Hodi, F. Stephen; Ibrahim, Ramy; Anderson, Aparna; Humphrey, Rachel; Blumenstein, Brent; Wolchok, Jedd

    2010-01-01

    Unlike chemotherapy, which acts directly on the tumor, cancer immunotherapies exert their effects on the immune system and demonstrate new kinetics that involve building a cellular immune response, followed by changes in tumor burden or patient survival. Thus, adequate design and evaluation of some immunotherapy clinical trials require a new development paradigm that includes reconsideration of established endpoints. Between 2004 and 2009, several initiatives facilitated by the Cancer Immunotherapy Consortium of the Cancer Research Institute and partner organizations systematically evaluated an immunotherapy-focused clinical development paradigm and created the principles for redefining trial endpoints. On this basis, a body of clinical and laboratory data was generated that supports three novel endpoint recommendations. First, cellular immune response assays generate highly variable results. Assay harmonization in multicenter trials may minimize variability and help to establish cellular immune response as a reproducible biomarker, thus allowing investigation of its relationship with clinical outcomes. Second, immunotherapy may induce novel patterns of antitumor response not captured by Response Evaluation Criteria in Solid Tumors or World Health Organization criteria. New immune-related response criteria were defined to more comprehensively capture all response patterns. Third, delayed separation of Kaplan–Meier curves in randomized immunotherapy trials can affect results. Altered statistical models describing hazard ratios as a function of time and recognizing differences before and after separation of curves may allow improved planning of phase III trials. These recommendations may improve our tools for cancer immunotherapy trials and may offer a more realistic and useful model for clinical investigation. PMID:20826737

  12. Quality of full and final publications reporting acute stroke trials: a systematic review.

    PubMed

    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

  13. Poor reporting of scientific leadership information in clinical trial registers.

    PubMed

    Sekeres, Melanie; Gold, Jennifer L; Chan, An-Wen; Lexchin, Joel; Moher, David; Van Laethem, Marleen L P; Maskalyk, James; Ferris, Lorraine; Taback, Nathan; Rochon, Paula A

    2008-02-20

    In September 2004, the International Committee of Medical Journal Editors (ICMJE) issued a Statement requiring that all clinical trials be registered at inception in a public register in order to be considered for publication. The World Health Organization (WHO) and ICMJE have identified 20 items that should be provided before a trial is considered registered, including contact information. Identifying those scientifically responsible for trial conduct increases accountability. The objective is to examine the proportion of registered clinical trials providing valid scientific leadership information. We reviewed clinical trial entries listing Canadian investigators in the two largest international and public trial registers, the International Standard Randomized Controlled Trial Number (ISRCTN) register, and ClinicalTrials.gov. The main outcome measures were the proportion of clinical trials reporting valid contact information for the trials' Principal Investigator (PI)/Co-ordinating Investigator/Study Chair/Site PI, and trial e-mail contact address, stratified by funding source, recruiting status, and register. A total of 1388 entries (142 from ISRCTN and 1246 from ClinicalTrials.gov) comprised our sample. We found non-compliance with mandatory registration requirements regarding scientific leadership and trial contact information. Non-industry and partial industry funded trials were significantly more likely to identify the individual responsible for scientific leadership (OR = 259, 95% CI: 95-701) and to provide a contact e-mail address (OR = 9.6, 95% CI: 6.6-14) than were solely industry funded trials. Despite the requirements set by WHO and ICMJE, data on scientific leadership and contact e-mail addresses are frequently omitted from clinical trials registered in the two leading public clinical trial registers. To promote accountability and transparency in clinical trials research, public clinical trials registers should ensure adequate monitoring of trial

  14. Randomized trials published in some Chinese journals: how many are randomized?

    PubMed

    Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David

    2009-07-02

    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.

  15. Randomized trials published in some Chinese journals: how many are randomized?

    PubMed Central

    Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David

    2009-01-01

    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

  16. Region 8: Colorado Telluride Adequate Letter (8/17/2011)

    EPA Pesticide Factsheets

    This March 4, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Telluride, CO PM10 maintenance plan and the 2021 motor vehicle emisssions budget (MVEB) adequate

  17. Trial endpoints for drug approval in oncology: Chemoprevention.

    PubMed

    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.

  18. Physiotherapy Post Lumbar Discectomy: Prospective Feasibility and Pilot Randomised Controlled Trial

    PubMed Central

    Rushton, Alison; Goodwin, Peter C.

    2015-01-01

    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

  19. Cognitive-behavioural suicide prevention for male prisoners: a pilot randomized controlled trial.

    PubMed

    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.

  20. How to Evaluate Phase Differences between Trial Groups in Ongoing Electrophysiological Signals

    PubMed Central

    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

  1. Miniature Radioisotope Thermoelectric Power Cubes

    NASA Technical Reports Server (NTRS)

    Patel, Jagdish U.; Fleurial, Jean-Pierre; Snyder, G. Jeffrey; Caillat, Thierry

    2004-01-01

    Cube-shaped thermoelectric devices energized by a particles from radioactive decay of Cm-244 have been proposed as long-lived sources of power. These power cubes are intended especially for incorporation into electronic circuits that must operate in dark, extremely cold locations (e.g., polar locations or deep underwater on Earth, or in deep interplanetary space). Unlike conventional radioisotope thermoelectric generators used heretofore as central power sources in some spacecraft, the proposed power cubes would be small enough (volumes would range between 0.1 and 0.2 cm3) to play the roles of batteries that are parts of, and dedicated to, individual electronic-circuit packages. Unlike electrochemical batteries, these power cubes would perform well at low temperatures. They would also last much longer: given that the half-life of Cm-244 is 18 years, a power cube could remain adequate as a power source for years, depending on the power demand in its particular application.

  2. Does Ureaplasma spp. cause chronic lung disease of prematurity: Ask the audience?

    PubMed Central

    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

  3. A best practice fall prevention exercise program to improve balance, strength / power, and psychosocial health in older adults: study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    Background With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested. Methods/Design Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale – International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with

  4. 75 FR 76498 - Firstenergy Nuclear Operating Company, Davis-Besse Nuclear Power Station; Environmental...

    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...

  5. 9 CFR 2.40 - Attending veterinarian and adequate veterinary care (dealers and exhibitors).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... veterinary care (dealers and exhibitors). 2.40 Section 2.40 Animals and Animal Products ANIMAL AND PLANT... and Adequate Veterinary Care § 2.40 Attending veterinarian and adequate veterinary care (dealers and... veterinary care to its animals in compliance with this section. (1) Each dealer and exhibitor shall employ an...

  6. 9 CFR 2.40 - Attending veterinarian and adequate veterinary care (dealers and exhibitors).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... veterinary care (dealers and exhibitors). 2.40 Section 2.40 Animals and Animal Products ANIMAL AND PLANT... and Adequate Veterinary Care § 2.40 Attending veterinarian and adequate veterinary care (dealers and... veterinary care to its animals in compliance with this section. (1) Each dealer and exhibitor shall employ an...

  7. Current strategies for the restoration of adequate lordosis during lumbar fusion

    PubMed Central

    Barrey, Cédric; Darnis, Alice

    2015-01-01

    Not restoring the adequate lumbar lordosis during lumbar fusion surgery may result in mechanical low back pain, sagittal unbalance and adjacent segment degeneration. The objective of this work is to describe the current strategies and concepts for restoration of adequate lordosis during fusion surgery. Theoretical lordosis can be evaluated from the measurement of the pelvic incidence and from the analysis of spatial organization of the lumbar spine with 2/3 of the lordosis given by the L4-S1 segment and 85% by the L3-S1 segment. Technical aspects involve patient positioning on the operating table, release maneuvers, type of instrumentation used (rod, screw-rod connection, interbody cages), surgical sequence and the overall surgical strategy. Spinal osteotomies may be required in case of fixed kyphotic spine. AP combined surgery is particularly efficient in restoring lordosis at L5-S1 level and should be recommended. Finally, not one but several strategies may be used to achieve the need for restoration of adequate lordosis during fusion surgery. PMID:25621216

  8. Optimal Order of Successive Office Hysteroscopy and Endometrial Biopsy for the Evaluation of Abnormal Uterine Bleeding: A Randomized Controlled Trial.

    PubMed

    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.

  9. Can exercise improve self esteem in children and young people? A systematic review of randomised controlled trials.

    PubMed

    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.

  10. 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...

  11. 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...

  12. 4 CFR 200.14 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... identifiable personal data and automated systems shall be adequately trained in the security and privacy of... the security and privacy of such records. (5) The disposal and destruction of identifiable personal....14 Section 200.14 Accounts RECOVERY ACCOUNTABILITY AND TRANSPARENCY BOARD PRIVACY ACT OF 1974 § 200...

  13. 4 CFR 200.14 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... identifiable personal data and automated systems shall be adequately trained in the security and privacy of....14 Section 200.14 Accounts RECOVERY ACCOUNTABILITY AND TRANSPARENCY BOARD PRIVACY ACT OF 1974 § 200... records in which identifiable personal data are processed or maintained, including all reports and output...

  14. A Bayesian adaptive design for biomarker trials with linked treatments

    PubMed Central

    Wason, James M S; Abraham, Jean E; Baird, Richard D; Gournaris, Ioannis; Vallier, Anne-Laure; Brenton, James D; Earl, Helena M; Mander, Adrian P

    2015-01-01

    Background: 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. Methods: 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. Results: 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. Conclusions: This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously. PMID:26263479

  15. A Bayesian adaptive design for biomarker trials with linked treatments.

    PubMed

    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.

  16. The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials.

    PubMed

    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

  17. Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School

    ERIC Educational Resources Information Center

    Miciak, Jeremy; Stuebing, Karla K.; Vaughn, Sharon; Roberts, Greg; Barth, Amy E.; Fletcher, Jack M.

    2014-01-01

    No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders (n = 77) and inadequate responders who fell below criteria in (a) comprehension (n = 54); (b) fluency (n = 45);…

  18. Power Calculations to Select Instruments for Clinical Trial Secondary Endpoints. A Case Study of Instrument Selection for Post-Traumatic Stress Symptoms in Subjects with Acute Respiratory Distress Syndrome.

    PubMed

    Sjoding, Michael W; Schoenfeld, David A; Brown, Samuel M; Hough, Catherine L; Yealy, Donald M; Moss, Marc; Angus, Derek C; Iwashyna, Theodore J

    2017-01-01

    After the sample size of a randomized clinical trial (RCT) is set by the power requirement of its primary endpoint, investigators select secondary endpoints while unable to further adjust sample size. How the sensitivity and specificity of an instrument used to measure these outcomes, together with their expected underlying event rates, affect an RCT's power to measure significant differences in these outcomes is poorly understood. Motivated by the design of an RCT of neuromuscular blockade in acute respiratory distress syndrome, we examined how power to detect a difference in secondary endpoints varies with the sensitivity and specificity of the instrument used to measure such outcomes. We derived a general formula and Stata code for calculating an RCT's power to detect differences in binary outcomes when such outcomes are measured with imperfect sensitivity and specificity. The formula informed the choice of instrument for measuring post-traumatic stress-like symptoms in the Reevaluation of Systemic Early Neuromuscular Blockade RCT ( www.clinicaltrials.gov identifier NCT02509078). On the basis of published sensitivities and specificities, the Impact of Events Scale-Revised was predicted to measure a 36% symptom rate, whereas the Post-Traumatic Stress Symptoms instrument was predicted to measure a 23% rate, if the true underlying rate of post-traumatic stress symptoms were 25%. Despite its lower sensitivity, the briefer Post-Traumatic Stress Symptoms instrument provided superior power to detect a difference in rates between trial arms, owing to its higher specificity. Examining instruments' power to detect differences in outcomes may guide their selection when multiple instruments exist, each with different sensitivities and specificities.

  19. 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...

  20. 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...

  1. Canadian aeronautical mobile data trials

    NASA Technical Reports Server (NTRS)

    Pedersen, Allister; Pearson, Andrea

    1993-01-01

    This paper describes a series of aeronautical mobile data trials conducted on small aircraft (helicopters and fixed wing) utilizing a low-speed store-and-forward mobile data service. The paper outlines the user requirements for aeronautical mobile satellite communications. 'Flight following' and improved wide-area dispatch communications were identified as high priority requirements. A 'proof-of-concept' trial in a Cessna Skymaster aircraft is described. This trial identified certain development work as essential to the introduction of commercial service including antenna development, power supply modifications and doppler software modifications. Other improvements were also proposed. The initial aeronautical mobile data service available for pre-operational (Beta) trials is outlined. Pre-operational field trials commenced in October 1992 and consisted of installations on a Gralen Communications Inc. Cessna 177 and an Aerospatiale Astar 350 series light single engine helicopter. The paper concludes with a discussion of desirable near term mobile data service developments, commercial benefits, current safety benefits and potential future applications for improved safety.

  2. Recruitment failure and futility were the most common reasons for discontinuation of clinical drug trials. Results of a nationwide inception cohort study in the Netherlands.

    PubMed

    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.

  3. 34 CFR 200.14 - Components of Adequate Yearly Progress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Components of Adequate Yearly Progress. 200.14 Section 200.14 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION TITLE I-IMPROVING THE ACADEMIC ACHIEVEMENT OF THE DISADVANTAGED...

  4. 13 CFR 108.200 - Adequate capital for NMVC Companies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Adequate capital for NMVC Companies. 108.200 Section 108.200 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM Qualifications for the NMVC Program Capitalizing A Nmvc Company § 108.200...

  5. The power prior: theory and applications.

    PubMed

    Ibrahim, Joseph G; Chen, Ming-Hui; Gwon, Yeongjin; Chen, Fang

    2015-12-10

    The power prior has been widely used in many applications covering a large number of disciplines. The power prior is intended to be an informative prior constructed from historical data. It has been used in clinical trials, genetics, health care, psychology, environmental health, engineering, economics, and business. It has also been applied for a wide variety of models and settings, both in the experimental design and analysis contexts. In this review article, we give an A-to-Z exposition of the power prior and its applications to date. We review its theoretical properties, variations in its formulation, statistical contexts for which it has been used, applications, and its advantages over other informative priors. We review models for which it has been used, including generalized linear models, survival models, and random effects models. Statistical areas where the power prior has been used include model selection, experimental design, hierarchical modeling, and conjugate priors. Frequentist properties of power priors in posterior inference are established, and a simulation study is conducted to further examine the empirical performance of the posterior estimates with power priors. Real data analyses are given illustrating the power prior as well as the use of the power prior in the Bayesian design of clinical trials. Copyright © 2015 John Wiley & Sons, Ltd.

  6. The Power Prior: Theory and Applications

    PubMed Central

    Ibrahim, Joseph G.; Chen, Ming-Hui; Gwon, Yeongjin; Chen, Fang

    2015-01-01

    The power prior has been widely used in many applications covering a large number of disciplines. The power prior is intended to be an informative prior constructed from historical data. It has been used in clinical trials, genetics, health care, psychology, environmental health, engineering, economics, and business. It has also been applied for a wide variety of models and settings, both in the experimental design and analysis contexts. In this review article, we give an A to Z exposition of the power prior and its applications to date. We review its theoretical properties, variations in its formulation, statistical contexts for which it has been used, applications, and its advantages over other informative priors. We review models for which it has been used, including generalized linear models, survival models, and random effects models. Statistical areas where the power prior has been used include model selection, experimental design, hierarchical modeling, and conjugate priors. Prequentist properties of power priors in posterior inference are established and a simulation study is conducted to further examine the empirical performance of the posterior estimates with power priors. Real data analyses are given illustrating the power prior as well as the use of the power prior in the Bayesian design of clinical trials. PMID:26346180

  7. Influence of environmental temperature on 40 km cycling time-trial performance.

    PubMed

    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.

  8. Region 9: California Adequate / Inadequate Letter Attachment (5/30/2008)

    EPA Pesticide Factsheets

    This is a document that states that it has been found adequate for transportation conformitypurposes certain 8-hour ozone and PM2.5 motor vehicleemissions budgets in the 2007 South Coast StateImplementation Plan.

  9. Cycling performance is superior for time-to-exhaustion versus time-trial in endurance laboratory tests.

    PubMed

    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.

  10. 10 CFR 1304.114 - Responsibility for maintaining adequate safeguards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the security and privacy of personal data. (4) The disposal and disposition of identifiable personal... contained in a system of records are adequately trained to protect the security and privacy of such records....114 Section 1304.114 Energy NUCLEAR WASTE TECHNICAL REVIEW BOARD PRIVACY ACT OF 1974 § 1304.114...

  11. Is the Stock of VET Skills Adequate? Assessment Methodologies.

    ERIC Educational Resources Information Center

    Blandy, Richard; Freeland, Brett

    In Australia and elsewhere, four approaches have been used to determine whether stocks of vocational education and training (VET) skills are adequate to meet industry needs. The four methods are as follows: (1) the manpower requirements approach; (2) the international, national, and industry comparisons approach; (3) the labor market analysis…

  12. Practical considerations for estimating clinical trial accrual periods: application to a multi-center effectiveness study

    PubMed Central

    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

  13. The Basilar Artery International Cooperation Study (BASICS): study protocol for a randomised controlled trial

    PubMed Central

    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

  14. Harm, benefit and costs associated with low-dose glucocorticoids added to the treatment strategies for rheumatoid arthritis in elderly patients (GLORIA trial): study protocol for a randomised controlled trial.

    PubMed

    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

  15. Stem cells in clinical trials for treatment of retinal degeneration.

    PubMed

    Klassen, Henry

    2016-01-01

    After decades of basic science research involving the testing of regenerative strategies in animal models of retinal degenerative diseases, a number of clinical trials are now underway, with additional trials set to begin shortly. These efforts will evaluate the safety and preliminary efficacy of cell-based products in the eyes of patients with a number of retinal conditions, notably including age-related macular degeneration, retinitis pigmentosa and Stargardt's disease. This review considers the scientific work and early trials with fetal cells and tissues that set the stage for the current clinical investigatory work, as well the trials themselves, specifically those either now completed, underway or close to initiation. The cells of interest include retinal pigment epithelial cells derived from embryonic stem or induced pluripotent stem cells, undifferentiated neural or retinal progenitors or cells from the vascular/bone marrow compartment or umbilical cord tissue. Degenerative diseases of the retina represent a popular target for emerging cell-based therapeutics and initial data from early stage clinical trials suggest that short-term safety objectives can be met in at least some cases. The question of efficacy will require additional time and testing to be adequately resolved.

  16. A randomized trial of enhanced HIV risk-reduction and vaccine trial education interventions among HIV-negative, high-risk women who use noninjection drugs: the UNITY study.

    PubMed

    Koblin, Beryl A; Bonner, Sebastian; Hoover, Donald R; Xu, Guozhen; Lucy, Debbie; Fortin, Princess; Putnam, Sara; Latka, Mary H

    2010-03-01

    Limited data are available on interventions to reduce sexual risk behaviors and increase knowledge of HIV vaccine trial concepts in high-risk populations eligible to participate in HIV vaccine efficacy trials. The UNITY Study was a 2-arm randomized trial to determine the efficacy of enhanced HIV risk-reduction and vaccine trial education interventions to reduce the occurrence of unprotected vaginal sex acts and increase HIV vaccine trial knowledge among 311 HIV-negative noninjection drug using women. The enhanced vaccine education intervention using pictures along with application vignettes and enhanced risk-reduction counseling consisting of 3 one-on-one counseling sessions were compared with standard conditions. Follow-up visits at 1 week and 1, 6, and 12 months after randomization included HIV testing and assessment of outcomes. During follow-up, the percent of women reporting sexual risk behaviors declined significantly but did not differ significantly by study arm. Knowledge of HIV vaccine trial concepts significantly increased but did not significantly differ by study arm. Concepts about HIV vaccine trials not adequately addressed by either condition included those related to testing a vaccine for both efficacy and safety, guarantees about participation in future vaccine trials, assurances of safety, medical care, and assumptions about any protective effect of a test vaccine. Further research is needed to boost educational efforts and strengthen risk-reduction counseling among high-risk noninjection drug using women.

  17. Do implant overdentures improve dietary intake? A randomized clinical trial.

    PubMed

    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.

  18. Comparative study of outcome measures and analysis methods for traumatic brain injury trials.

    PubMed

    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.

  19. Comparative Study of Outcome Measures and Analysis Methods for Traumatic Brain Injury Trials

    PubMed Central

    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

  20. Next-generation clinical trials: Novel strategies to address the challenge of tumor molecular heterogeneity.

    PubMed

    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

  1. Weight management for adolescents with intellectual and developmental disabilities: Rationale and design for an 18month randomized trial.

    PubMed

    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.

  2. Customizing elastic pressure bandages for reuse to a predetermined, sub-bandage pressure: A randomized controlled trial.

    PubMed

    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.

  3. Distributed Space Solar Power

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.

    2001-01-01

    The objective was to assess the feasibility of safely collecting solar power at geostationary orbit and delivering it to earth. A strategy which could harness a small fraction of the millions of gigawatts of sunlight passing near earth could adequately supply the power needs of earth and those of space exploration far into the future. Light collected and enhanced both spatially and temporally in space and beamed to earth provides probably the only practical means of safe and efficient delivery of this space solar power to earth. In particular, we analyzed the feasibility of delivering power to sites on earth at a comparable intensity, after conversion to a usable form, to existing power needs. Two major obstacles in the delivery of space solar power to earth are safety and the development of a source suitable for space. We focused our approach on: (1) identifying system requirements and designing a strategy satisfying current eye and skin safety requirements; and (2) identifying a concept for a potential space-based source for producing the enhanced light.

  4. Smoking characteristics and comorbidities in the power to quit randomized clinical trial for homeless smokers.

    PubMed

    Okuyemi, Kolawole S; Goldade, Kate; Whembolua, Guy-Lucien; Thomas, Janet L; Eischen, Sara; Guo, Hongfei; Connett, John E; Grant, Jon; Ahluwalia, Jasjit S; Resnicow, Ken; Owen, Greg; Gelberg, Lillian; Jarlais, Don Des

    2013-01-01

    Smoking prevalence in homeless populations is strikingly high (∼70%); yet, little is known about effective smoking cessation interventions for this population. We conducted a community-based clinical trial, Power To Quit (PTQ), to assess the effects of motivational interviewing (MI) and nicotine patch (nicotine replacement therapy [NRT]) on smoking cessation among homeless smokers. This paper describes the smoking characteristics and comorbidities of smokers in the study. Four hundred and thirty homeless adult smokers were randomized to either the intervention arm (NRT + MI) or the control arm (NRT + Brief Advice). Baseline assessment included demographic information, shelter status, smoking history, motivation to quit smoking, alcohol/other substance abuse, and psychiatric comorbidities. Of the 849 individuals who completed the eligibility survey, 578 (68.1%) were eligible and 430 (74.4% of eligibles) were enrolled. Participants were predominantly Black, male, and had mean age of 44.4 years (S D = 9.9), and the majority were unemployed (90.5%). Most participants reported sleeping in emergency shelters; nearly half had been homeless for more than a year. Nearly all the participants were daily smokers who smoked an average of 20 cigarettes/day. Nearly 40% had patient health questionnaire-9 depression scores in the moderate or worse range, and more than 80% screened positive for lifetime history of drug abuse or dependence. This study demonstrates the feasibility of enrolling a diverse sample of homeless smokers into a smoking cessation clinical trial. The uniqueness of the study sample enables investigators to examine the influence of nicotine dependence as well as psychiatric and substance abuse comorbidities on smoking cessation outcomes.

  5. Placebo effect in clinical trial design for irritable bowel syndrome.

    PubMed

    Shah, Eric; Pimentel, Mark

    2014-04-30

    Ongoing efforts to improve clinical trial design in irritable bowel syndrome have been hindered by high placebo response rates and ineffective outcome measures. We assessed established strategies to minimize placebo effect as well as the various ap-proaches to placebo effect which can affect trial design. These include genetic markers such as catechol-O-methyltransferase, opioidergic and dopaminergic neurobiologic theory, pre-cebo effect centered on expectancy theory, and side effect unblinding grounded on conditioning theory. We reviewed endpoints used in the study of IBS over the past decade including adequate relief and subjective global relief, emphasizing their weaknesses in fully evaluating the IBS condition, specifically their motility effects based on functional net value and relative benefit-harm based on dropouts due to adverse events. The focus of this review is to highlight ongoing efforts to improve clinical trial design which can lead to better outcomes in a real-world setting.

  6. Randomized controlled trial of parent-enhanced CBT compared with individual CBT for obsessive-compulsive disorder in young people.

    PubMed

    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.

  7. Feasibility of high-intensity interval training and moderate-intensity continuous training in adults with inactive or mildly active Crohn's disease: study protocol for a randomised controlled trial.

    PubMed

    Tew, Garry A; Carpenter, Roger; Seed, Michael; Anderson, Simon; Langmead, Louise; Fairhurst, Caroline; Bottoms, Lindsay

    2017-01-01

    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.

  8. Do Beginning Teachers Receive Adequate Support from Their Headteachers?

    ERIC Educational Resources Information Center

    Menon, Maria Eliophotou

    2012-01-01

    The article examines the problems faced by beginning teachers in Cyprus and the extent to which headteachers are considered to provide adequate guidance and support to them. Data were collected through interviews with 25 school teachers in Cyprus, who had recently entered teaching (within 1-5 years) in public primary schools. According to the…

  9. Feasibility of Image-Guided Transthoracic Core Needle Biopsy in the BATTLE Lung Trial

    PubMed Central

    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

  10. Design of clinical trials evaluating dietary interventions in patients with functional gastrointestinal disorders.

    PubMed

    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.

  11. A feasibility study and pilot randomised trial of a tailored prevention program to reduce falls in older people with mild dementia.

    PubMed

    Wesson, Jacqueline; Clemson, Lindy; Brodaty, Henry; Lord, Stephen; Taylor, Morag; Gitlin, Laura; Close, Jacqueline

    2013-09-03

    : 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.

  12. Power Calculations to Select Instruments for Clinical Trial Secondary Endpoints. A Case Study of Instrument Selection for Post-Traumatic Stress Symptoms in Subjects with Acute Respiratory Distress Syndrome

    PubMed Central

    Schoenfeld, David A.; Brown, Samuel M.; Hough, Catherine L.; Yealy, Donald M.; Moss, Marc; Angus, Derek C.; Iwashyna, Theodore J.

    2017-01-01

    Rationale: After the sample size of a randomized clinical trial (RCT) is set by the power requirement of its primary endpoint, investigators select secondary endpoints while unable to further adjust sample size. How the sensitivity and specificity of an instrument used to measure these outcomes, together with their expected underlying event rates, affect an RCT’s power to measure significant differences in these outcomes is poorly understood. Objectives: Motivated by the design of an RCT of neuromuscular blockade in acute respiratory distress syndrome, we examined how power to detect a difference in secondary endpoints varies with the sensitivity and specificity of the instrument used to measure such outcomes. Methods: We derived a general formula and Stata code for calculating an RCT’s power to detect differences in binary outcomes when such outcomes are measured with imperfect sensitivity and specificity. The formula informed the choice of instrument for measuring post-traumatic stress–like symptoms in the Reevaluation of Systemic Early Neuromuscular Blockade RCT (www.clinicaltrials.gov identifier NCT02509078). Measurements and Main Results: On the basis of published sensitivities and specificities, the Impact of Events Scale-Revised was predicted to measure a 36% symptom rate, whereas the Post-Traumatic Stress Symptoms instrument was predicted to measure a 23% rate, if the true underlying rate of post-traumatic stress symptoms were 25%. Despite its lower sensitivity, the briefer Post-Traumatic Stress Symptoms instrument provided superior power to detect a difference in rates between trial arms, owing to its higher specificity. Conclusions: Examining instruments’ power to detect differences in outcomes may guide their selection when multiple instruments exist, each with different sensitivities and specificities. PMID:27788018

  13. Changing cluster composition in cluster randomised controlled trials: design and analysis considerations

    PubMed Central

    2014-01-01

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

  14. Assessment of Power Potential of Tidal Currents and Impacts of Power Extraction on Flow Speeds in Indonesia

    NASA Astrophysics Data System (ADS)

    Orhan, K.; Mayerle, R.

    2016-12-01

    A methodology comprising of the estimates of power yield, evaluation of the effects of power extraction on flow conditions, and near-field investigations to deliver wake characteritics, recovery and interactions is described and applied to several straits in Indonesia. Site selection is done with high-resolution, three-dimensional flow models providing sufficient spatiotemporal coverage. Much attention has been given to the meteorological forcing, and conditions at the open sea boundaries to adequately capture the density gradients and flow fields. Model verification using tidal records shows excellent agreement. Sites with adequate depth for the energy conversion using horizontal axis tidal turbines, average kinetic power density greater than 0.5 kW/m2, and surface area larger than 0.5km2 are defined as energy hotspots. Spatial variation of the average extractable electric power is determined, and annual tidal energy resource is estimated for the straits in question. The results showed that the potential for tidal power generation in Indonesia is likely to exceed previous predictions reaching around 4,800MW. To assess the impact of the devices, flexible mesh models with higher resolutions have been developed. Effects on flow conditions, and near-field turbine wakes are resolved in greater detail with triangular horizontal grids. The energy is assumed to be removed uniformly by sub-grid scale arrays of turbines, and calculations are made based on velocities at the hub heights of the devices. An additional drag force resulting in dissipation of the pre-existing kinetic power from %10 to %60 within a flow cross-section is introduced to capture the impacts. It was found that the effect of power extraction on water levels and flow speeds in adjacent areas is not significant. Results show the effectivess of the method to capture wake characteritics and recovery reasonably well with low computational cost.

  15. Prestimulus Alpha Power Influences Tactile Temporal Perceptual Discrimination and Confidence in Decisions.

    PubMed

    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.

  16. Randomized trial of a telephone-based weight loss intervention in postmenopausal women with breast cancer receiving letrozole: the LISA trial.

    PubMed

    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.

  17. Pilot and Repeat Trials as Development Tools Associated with Demonstration of Bioequivalence.

    PubMed

    Fuglsang, Anders

    2015-05-01

    The purpose of this work is to use simulated trials to study how pilot trials can be implemented in relation to bioequivalence testing, and how the use of the information obtained at the pilot stage can influence the overall chance of showing bioequivalence (power) or the chance of approving a truly bioinequivalent product (type I error). The work also covers the use of repeat pivotal trials since the difference between a pilot trial followed by a pivotal trial and a pivotal trial followed by a repeat trial is mainly a question of whether a conclusion of bioequivalence can be allowed after the first trial. Repeating a pivotal trial after a failed trial involves dual or serial testing of the bioequivalence null hypothesis, and the paper illustrates how this may inflate the type I error up to almost 10%. Hence, it is questioned if such practice is in the interest of patients. Tables for power, type I error, and sample sizes are provided for a total of six different decision trees which allow the developer to use either the observed geometric mean ratio (GMR) from the first or trial or to assume that the GMR is 0.95. In cases when the true GMR can be controlled so as not to deviate more from unity than 0.95, sequential design methods ad modum Potvin may be superior to pilot trials. The tables provide a quantitative basis for choosing between sequential designs and pivotal trials preceded by pilot trials.

  18. Analysis and interpretation of cost data in randomised controlled trials: review of published studies

    PubMed Central

    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

  19. Powered lower limb orthoses for gait rehabilitation

    PubMed Central

    Ferris, Daniel P.; Sawicki, Gregory S.; Domingo, Antoinette

    2006-01-01

    Bodyweight supported treadmill training has become a prominent gait rehabilitation method in leading rehabilitation centers. This type of locomotor training has many functional benefits but the labor costs are considerable. To reduce therapist effort, several groups have developed large robotic devices for assisting treadmill stepping. A complementary approach that has not been adequately explored is to use powered lower limb orthoses for locomotor training. Recent advances in robotic technology have made lightweight powered orthoses feasible and practical. An advantage to using powered orthoses as rehabilitation aids is they allow practice starting, turning, stopping, and avoiding obstacles during overground walking. PMID:16568153

  20. Feasibility of a Trial on Improvisational Music Therapy for Children with Autism Spectrum Disorder.

    PubMed

    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.

  1. Resistance profile of darunavir: combined 24-week results from the POWER trials.

    PubMed

    de Meyer, Sandra; Vangeneugden, Tony; van Baelen, Ben; de Paepe, Els; van Marck, Herwig; Picchio, Gaston; Lefebvre, Eric; de Béthune, Marie-Pierre

    2008-03-01

    The resistance profile of darunavir (TMC114) in treatment-experienced patients was explored using pooled week 24 data from POWER 1, 2, and 3 at the recommended dose of darunavir with low-dose ritonavir (darunavir/r, 600/100 mg bid, N = 458). Baseline darunavir fold change in EC(50) was a strong predictor of virological response at week 24. Preliminary phenotypic clinical cut-offs of 10 and 40 were established. Virological response to darunavir/r was maintained in the presence at baseline of a high number of IAS-USA PI resistance-associated mutations (IAS-USA PI RAMS); a diminished response occurred with >or=14. Eleven protease mutations associated with diminished darunavir/r virological response were identified (V11I, V32I, L33F, I47V, I50V, I54L/M, G73S, L76V, I84V, and L89V). These darunavir resistance-associated mutations (DRV RAMS) occurred in the presence of a high number of IAS-USA PI RAMS. Virological response was diminished with three or more DRV RAMS in the background of a high number of IAS-USA PI RAMS. Incremental numbers of DRV RAMS were more predictive of outcome than were IAS-USA PI RAMS. Mutations developing during darunavir/r virological failure (V32I, L33F, I47V, I54L, and L89V) were also featured in the DRV RAMS list. Site-directed mutants carrying these five mutations, or any one of these mutations either alone or together with one or two IAS-USA PI RAMS, showed no reduced darunavir susceptibility, suggesting that a high number of additional background mutations is required for darunavir resistance. In this population of treatment-experienced patients, darunavir/r demonstrated significantly greater efficacy than investigator-selected control PIs of trials POWER 1 and 2, regardless of baseline viral genotype or phenotype, while exhibiting a high genetic barrier to the development of resistance.

  2. Region 8: Colorado Canon City Adequate Letter (8/17/2011)

    EPA Pesticide Factsheets

    This May 4, 2011 letter from EPA to Chistopher E. Urbina M.D., MPH, Colorado Department of Public Health and Environment states that EPA has found that the Canon City PM10 maintenance plan and the 2020 motor vehicle emissions budget (MVEB) adequate

  3. Large-scale randomized clinical trials of bioactives and nutrients in relation to human health and disease prevention - Lessons from the VITAL and COSMOS trials.

    PubMed

    Rautiainen, Susanne; Sesso, Howard D; Manson, JoAnn E

    2017-12-29

    Several bioactive compounds and nutrients in foods have physiological properties that are beneficial for human health. While nutrients typically have clear definitions with established levels of recommended intakes, bioactive compounds often lack such a definition. Although a food-based approach is often the optimal approach to ensure adequate intake of bioactives and nutrients, these components are also often produced as dietary supplements. However, many of these supplements are not sufficiently studied and have an unclear role in chronic disease prevention. Randomized trials are considered the gold standard of study designs, but have not been fully applied to understand the effects of bioactives and nutrients. We review the specific role of large-scale trials to test whether bioactives and nutrients have an effect on health outcomes through several crucial components of trial design, including selection of intervention, recruitment, compliance, outcome selection, and interpretation and generalizability of study findings. We will discuss these components in the context of two randomized clinical trials, the VITamin D and OmegA-3 TriaL (VITAL) and the COcoa Supplement and Multivitamin Outcomes Study (COSMOS). We will mainly focus on dietary supplements of bioactives and nutrients while also emphasizing the need for translation and integration with food-based trials that are of vital importance within nutritional research. Copyright © 2017. Published by Elsevier Ltd.

  4. Trial Frame Refraction versus Autorefraction among New Patients in a Low-Vision Clinic

    PubMed Central

    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

  5. Trial frame refraction versus autorefraction among new patients in a low-vision clinic.

    PubMed

    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.

  6. Power technologies and the space future

    NASA Technical Reports Server (NTRS)

    Faymon, Karl A.; Fordyce, J. Stuart; Brandhorst, Henry W., Jr.

    1991-01-01

    Advancements in space power and energy technologies are critical to serve space development needs and help solve problems on Earth. The availability of low cost power and energy in space will be the hallmark of this advance. Space power will undergo a dramatic change for future space missions. The power systems which have served the U.S. space program so well in the past will not suffice for the missions of the future. This is especially true if the space commercialization is to become a reality. New technologies, and new and different space power architectures and topologies will replace the lower power, low-voltage systems of the past. Efficiencies will be markedly improved, specific powers will be greatly increased, and system lifetimes will be markedly extended. Space power technology is discussed - its past, its current status, and predictions about where it will go in the future. A key problem for power and energy is its cost of affordability. Power must be affordable or it will not serve future needs adequately. This aspect is also specifically addressed.

  7. Power of automated algorithms for combining time-line follow-back and urine drug screening test results in stimulant-abuse clinical trials.

    PubMed

    Oden, Neal L; VanVeldhuisen, Paul C; Wakim, Paul G; Trivedi, Madhukar H; Somoza, Eugene; Lewis, Daniel

    2011-09-01

    In clinical trials of treatment for stimulant abuse, researchers commonly record both Time-Line Follow-Back (TLFB) self-reports and urine drug screen (UDS) results. To compare the power of self-report, qualitative (use vs. no use) UDS assessment, and various algorithms to generate self-report-UDS composite measures to detect treatment differences via t-test in simulated clinical trial data. We performed Monte Carlo simulations patterned in part on real data to model self-report reliability, UDS errors, dropout, informatively missing UDS reports, incomplete adherence to a urine donation schedule, temporal correlation of drug use, number of days in the study period, number of patients per arm, and distribution of drug-use probabilities. Investigated algorithms include maximum likelihood and Bayesian estimates, self-report alone, UDS alone, and several simple modifications of self-report (referred to here as ELCON algorithms) which eliminate perceived contradictions between it and UDS. Among the algorithms investigated, simple ELCON algorithms gave rise to the most powerful t-tests to detect mean group differences in stimulant drug use. Further investigation is needed to determine if simple, naïve procedures such as the ELCON algorithms are optimal for comparing clinical study treatment arms. But researchers who currently require an automated algorithm in scenarios similar to those simulated for combining TLFB and UDS to test group differences in stimulant use should consider one of the ELCON algorithms. This analysis continues a line of inquiry which could determine how best to measure outpatient stimulant use in clinical trials (NIDA. NIDA Monograph-57: Self-Report Methods of Estimating Drug Abuse: Meeting Current Challenges to Validity. NTIS PB 88248083. Bethesda, MD: National Institutes of Health, 1985; NIDA. NIDA Research Monograph 73: Urine Testing for Drugs of Abuse. NTIS PB 89151971. Bethesda, MD: National Institutes of Health, 1987; NIDA. NIDA Research

  8. A feasibility study and pilot randomised trial of a tailored prevention program to reduce falls in older people with mild dementia

    PubMed Central

    2013-01-01

    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

  9. Approximating lens power.

    PubMed

    Kaye, Stephen B

    2009-04-01

    To provide a scalar measure of refractive error, based on geometric lens power through principal, orthogonal and oblique meridians, that is not limited to the paraxial and sag height approximations. A function is derived to model sections through the principal meridian of a lens, followed by rotation of the section through orthogonal and oblique meridians. Average focal length is determined using the definition for the average of a function. Average univariate power in the principal meridian (including spherical aberration), can be computed from the average of a function over the angle of incidence as determined by the parameters of the given lens, or adequately computed from an integrated series function. Average power through orthogonal and oblique meridians, can be similarly determined using the derived formulae. The widely used computation for measuring refractive error, the spherical equivalent, introduces non-constant approximations, leading to a systematic bias. The equations proposed provide a good univariate representation of average lens power and are not subject to a systematic bias. They are particularly useful for the analysis of aggregate data, correlating with biological treatment variables and for developing analyses, which require a scalar equivalent representation of refractive power.

  10. Lack of efficacy of a reduced microparticle diet in a multi-centred trial of patients with active Crohn's disease.

    PubMed

    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.

  11. Power Calculations and Placebo Effect for Future Clinical Trials in Progressive Supranuclear Palsy

    PubMed Central

    Stamelou, Maria; Schöpe, Jakob; Wagenpfeil, Stefan; Ser, Teodoro Del; Bang, Jee; Lobach, Iryna Y.; Luong, Phi; Respondek, Gesine; Oertel, Wolfgang H.; Boxer, Adam L.; Höglinger, Günter U.

    2016-01-01

    Background Two recent randomized, placebo-controlled trials of putative disease-modifying agents (davunetide, tideglusib) in progressive supranuclear palsy (PSP) failed to show efficacy, but generated data relevant for future trials. Methods We provide sample size calculations based on data collected in 187 PSP patients assigned to placebo in these trials. A placebo effect was calculated. Results The total PSP-Rating Scale required the least number of patients per group (N = 51) to detect a 50% change in the 1-year progression and 39 when including patients with ≤ 5 years disease duration. The Schwab and England Activities of Daily Living required 70 patients per group and was highly correlated with the PSP-Rating Scale. A placebo effect was not detected in these scales. Conclusions We propose the 1-year PSP-Rating Scale score change as the single primary readout in clinical neuroprotective or disease-modifying trials. The Schwab and England Activities of Daily Living could be used as a secondary outcome. PMID:26948290

  12. Developing a model for the adequate description of electronic communication in hospitals.

    PubMed

    Saboor, Samrend; Ammenwerth, Elske

    2011-01-01

    Adequate information and communication systems (ICT) can help to improve the communication in hospitals. Changes to the ICT-infrastructure of hospitals must be planed carefully. In order to support a comprehensive planning, we presented a classification of 81 common errors of the electronic communication on the MIE 2008 congress. Our objective now was to develop a data model that defines specific requirements for an adequate description of electronic communication processes We first applied the method of explicating qualitative content analysis on the error categorization in order to determine the essential process details. After this, we applied the method of subsuming qualitative content analysis on the results of the first step. A data model for the adequate description of electronic communication. This model comprises 61 entities and 91 relationships. The data model comprises and organizes all details that are necessary for the detection of the respective errors. It can be for either used to extend the capabilities of existing modeling methods or as a basis for the development of a new approach.

  13. Depression severity in electroconvulsive therapy (ECT) versus pharmacotherapy trials.

    PubMed

    Kellner, Charles H; Kaicher, David C; Banerjee, Hiya; Knapp, Rebecca G; Shapiro, Rachael J; Briggs, Mimi C; Pasculli, Rosa M; Popeo, Dennis M; Ahle, Gabriella M; Liebman, Lauren S

    2015-03-01

    We sought to compare the level of severity of depressive symptoms on entry into electroconvulsive therapy (ECT) clinical trials versus pharmacotherapy clinical trials. English-language MEDLINE/PubMed publication databases were searched for ECT literature (search terms: ECT, electroconvulsive therapy, depression, and Hamilton) for clinical trials in which depressed patients had baseline Hamilton Rating Scale for Depression (HRSD) scores. For comparison, we used a convenience sample of 7 large pharmacotherapy trials in major depression (N = 3677). The search included articles from 1960 to 2011. We included 100 studies that met the following criteria: ECT trial for depression, patients adequately characterized by diagnosis at baseline, and patients rated at baseline by 15-item HRSD (HRSD15), HRSD17, HRSD21, HRSD24, or HRSD28, with mean (SD) and sample size (n) reported. For the comparator pharmacotherapy trials, we chose to use a subset of the studies (excluding one study of minor depression) in the widely publicized meta-analysis of Fournier et al, as well as the STAR*D study and one additional study by Shelton et al. This provided 7 studies of major depression using HRSD17 (total N = 3677). Data extracted included number of subjects and baseline and final HRSD scores, with mean (SD) values. Of 100 ECT studies, 56 studies (N = 2243) used the HRSD17 version. The mean baseline HRSD17 score in the ECT trials was 27.6, the mean in the pharmacotherapy trials was 21.94, a statistically, and clinically, significant difference. In a subanalysis of the 16 ECT studies that used the HRSD24 version, the mean baseline score was 32.2. This selective literature review confirms that patients who entered ECT clinical trials were more severely ill than those who entered the selected comparator pharmacotherapy trials. Such data highlight the critical role of ECT in the treatment of severe and treatment-resistant mood disorders.

  14. Ignorance is not bliss: Statistical power is not probability of trial success.

    PubMed

    Zierhut, M L; Bycott, P; Gibbs, M A; Smith, B P; Vicini, P

    2016-04-01

    The purpose of this commentary is to place probability of trial success, or assurance, in the context of decision making in drug development, and to illustrate its properties in an intuitive manner for the readers of Clinical Pharmacology and Therapeutics. The hope is that this will stimulate a dialog on how assurance should be incorporated into a quantitative decision approach for clinical development and trial design that uses all available information. © 2015 ASCPT.

  15. Bayesian network meta-analysis for cluster randomized trials with binary outcomes.

    PubMed

    Uhlmann, Lorenz; Jensen, Katrin; Kieser, Meinhard

    2017-06-01

    Network meta-analysis is becoming a common approach to combine direct and indirect comparisons of several treatment arms. In recent research, there have been various developments and extensions of the standard methodology. Simultaneously, cluster randomized trials are experiencing an increased popularity, especially in the field of health services research, where, for example, medical practices are the units of randomization but the outcome is measured at the patient level. Combination of the results of cluster randomized trials is challenging. In this tutorial, we examine and compare different approaches for the incorporation of cluster randomized trials in a (network) meta-analysis. Furthermore, we provide practical insight on the implementation of the models. In simulation studies, it is shown that some of the examined approaches lead to unsatisfying results. However, there are alternatives which are suitable to combine cluster randomized trials in a network meta-analysis as they are unbiased and reach accurate coverage rates. In conclusion, the methodology can be extended in such a way that an adequate inclusion of the results obtained in cluster randomized trials becomes feasible. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Are phase 1 trials therapeutic? Risk, ethics, and division of labor.

    PubMed

    Anderson, James A; Kimmelman, Jonathan

    2014-03-01

    Despite their crucial role in the translation of pre-clinical research into new clinical applications, phase 1 trials involving patients continue to prompt ethical debate. At the heart of the controversy is the question of whether risks of administering experimental drugs are therapeutically justified. We suggest that prior attempts to address this question have been muddled, in part because it cannot be answered adequately without first attending to the way labor is divided in managing risk in clinical trials. In what follows, we approach the question of therapeutic justification for phase 1 trials from the viewpoint of five different stakeholders: the drug regulatory authority, the IRB, the clinical investigator, the referring physician, and the patient. Our analysis shows that the question of therapeutic justification actually raises multiple questions corresponding to the roles and responsibilities of the different stakeholders involved. By attending to these contextual differences, we provide more coherent guidance for the ethical negotiation of risk in phase 1 trials involving patients. We close by discussing the implications of our argument for various perennial controversies in phase 1 trial practice. © 2012 John Wiley & Sons Ltd.

  17. Calculation of the Cost of an Adequate Education in Kentucky: A Professional Judgment Approach

    ERIC Educational Resources Information Center

    Verstegen, Deborah A.

    2004-01-01

    What is an adequate education and how much does it cost? In 1989, Kentucky's State Supreme Court found the entire system of education unconstitutional--"all of its parts and parcels". The Court called for all children to have access to an adequate education, one that is uniform and has as its goal the development of seven capacities,…

  18. CORE-Hom: a powerful and exhaustive database of clinical trials in homeopathy.

    PubMed

    Clausen, Jürgen; Moss, Sian; Tournier, Alexander; Lüdtke, Rainer; Albrecht, Henning

    2014-10-01

    The CORE-Hom database was created to answer the need for a reliable and publicly available source of information in the field of clinical research in homeopathy. As of May 2014 it held 1048 entries of clinical trials, observational studies and surveys in the field of homeopathy, including second publications and re-analyses. 352 of the trials referenced in the database were published in peer reviewed journals, 198 of which were randomised controlled trials. The most often used remedies were Arnica montana (n = 103) and Traumeel(®) (n = 40). The most studied medical conditions were respiratory tract infections (n = 126) and traumatic injuries (n = 110). The aim of this article is to introduce the database to the public, describing and explaining the interface, features and content of the CORE-Hom database. Copyright © 2014 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  19. Vertical position of Chinese power words influences power judgments: Evidence from spatial compatibility task and event-related Potentials.

    PubMed

    Wu, Xiangci; Jia, Huibin; Wang, Enguo; Du, Chenguang; Wu, Xianghua; Dang, Caiping

    2016-04-01

    The present study used event-related potentials (ERPs) to explore the influence of vertical position on power judgments. Participants were asked to identify whether a Chinese word represented a powerful or powerless group (e.g., "king" or "servant"), which was presented in the top or bottom of the screen. The behavioral analysis showed that judging the power of powerful words were significantly faster when they were presented at the top position, compared with when they were presented at the bottom position. The ERP analysis showed enhanced N1 amplitude for congruent trials (i.e., the powerful words in the top and the powerless words in the bottom of the screen) and larger P300 and LPC amplitude for incongruent trials (i.e., the powerful words in the bottom and the powerless words in the top of the screen). The present findings provide further electrophysiological evidence that thinking about power can automatically activate the underlying spatial up-down (verticality) image schema and that the influence of vertical position on the power judgments not only occurs at the early perceptual stage of power word processing, but also at the higher cognitive stage (i.e., allocation of attention resources, conflict solving and response selection). This study revealed the neural underpinnings of metaphor congruent effect which have great significance to our understanding of the abstract concept power. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. 42 CFR 438.207 - Assurances of adequate capacity and services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS MANAGED CARE Quality Assessment and Performance Improvement Access Standards § 438.207 Assurances of adequate capacity and services. (a) Basic rule. The State... with the State's requirements for availability of services, as set forth in § 438.206. (e) CMS' right...

  1. Protocol design and current status of CLIVIT: a randomized controlled multicenter relevance trial comparing clips versus ligatures in thyroid surgery

    PubMed Central

    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

  2. Army General Fund Adjustments Not Adequately Documented or Supported

    DTIC Science & Technology

    2016-07-26

    compilation process. Finding The Office of the Assistant Secretary of the Army (Financial Management & Comptroller) (OASA[FM&C]) and the Defense Finance and...statements were unreliable and lacked an adequate audit trail. Furthermore, DoD and Army managers could not rely on the data in their accounting...systems when making management and resource decisions. Until the Army and DFAS Indianapolis correct these control deficiencies, there is considerable

  3. 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.

  4. Trial-to-trial adjustments of speed-accuracy trade-offs in premotor and primary motor cortex

    PubMed Central

    Guberman, Guido; Cisek, Paul

    2016-01-01

    Recent studies have shown that activity in sensorimotor structures varies depending on the speed-accuracy trade-off (SAT) context in which a decision is made. Here we tested the hypothesis that the same areas also reflect a more local adjustment of SAT established between individual trials, based on the outcome of the previous decision. Two monkeys performed a reaching decision task in which sensory evidence continuously evolves during the time course of a trial. In two SAT contexts, we compared neural activity in trials following a correct choice vs. those following an error. In dorsal premotor cortex (PMd), we found that 23% of cells exhibited significantly weaker baseline activity after error trials, and for ∼30% of these this effect persisted into the deliberation epoch. These cells also contributed to the process of combining sensory evidence with the growing urgency to commit to a choice. We also found that the activity of 22% of PMd cells was increased after error trials. These neurons appeared to carry less information about sensory evidence and time-dependent urgency. For most of these modulated cells, the effect was independent of whether the previous error was expected or unexpected. We found similar phenomena in primary motor cortex (M1), with 25% of cells decreasing and 34% increasing activity after error trials, but unlike PMd, these neurons showed less clear differences in their response properties. These findings suggest that PMd and M1 belong to a network of brain areas involved in SAT adjustments established using the recent history of reinforcement. NEW & NOTEWORTHY Setting the speed-accuracy trade-off (SAT) is crucial for efficient decision making. Previous studies have reported that subjects adjust their SAT after individual decisions, usually choosing more conservatively after errors, but the neural correlates of this phenomenon are only partially known. Here, we show that neurons in PMd and M1 of monkeys performing a reach decision task

  5. Sponsorship in non-commercial clinical trials: definitions, challenges and the role of Good Clinical Practices guidelines.

    PubMed

    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

  6. Prestimulus alpha power predicts fidelity of sensory encoding in perceptual decision making

    PubMed Central

    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

  7. 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...

  8. 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...

  9. 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...

  10. 9 CFR 2.33 - Attending veterinarian and adequate veterinary care.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... animal health, behavior, and well-being is conveyed to the attending veterinarian; (4) Guidance to... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Attending veterinarian and adequate veterinary care. 2.33 Section 2.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...

  11. 9 CFR 2.33 - Attending veterinarian and adequate veterinary care.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... animal health, behavior, and well-being is conveyed to the attending veterinarian; (4) Guidance to... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Attending veterinarian and adequate veterinary care. 2.33 Section 2.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...

  12. 9 CFR 2.33 - Attending veterinarian and adequate veterinary care.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... animal health, behavior, and well-being is conveyed to the attending veterinarian; (4) Guidance to... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Attending veterinarian and adequate veterinary care. 2.33 Section 2.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...

  13. 12 CFR 1229.5 - Capital distributions for adequately capitalized Banks.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CAPITAL CLASSIFICATIONS AND PROMPT CORRECTIVE ACTION Federal Home Loan Banks § 1229.5 Capital... classification of adequately capitalized. A Bank may not make a capital distribution if such distribution would... redeem its shares of stock if the transaction is made in connection with the issuance of additional Bank...

  14. Pedagogical Potential of Muslim Religious Sources in Overcoming Physical and Mental and Psychological Trials

    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…

  15. Proof of concept demonstration of optimal composite MRI endpoints for clinical trials.

    PubMed

    Edland, Steven D; Ard, M Colin; Sridhar, Jaiashre; Cobia, Derin; Martersteck, Adam; Mesulam, M Marsel; Rogalski, Emily J

    2016-09-01

    Atrophy measures derived from structural MRI are promising outcome measures for early phase clinical trials, especially for rare diseases such as primary progressive aphasia (PPA), where the small available subject pool limits our ability to perform meaningfully powered trials with traditional cognitive and functional outcome measures. We investigated a composite atrophy index in 26 PPA participants with longitudinal MRIs separated by two years. Rogalski et al . [ Neurology 2014;83:1184-1191] previously demonstrated that atrophy of the left perisylvian temporal cortex (PSTC) is a highly sensitive measure of disease progression in this population and a promising endpoint for clinical trials. Using methods described by Ard et al . [ Pharmaceutical Statistics 2015;14:418-426], we constructed a composite atrophy index composed of a weighted sum of volumetric measures of 10 regions of interest within the left perisylvian cortex using weights that maximize signal-to-noise and minimize sample size required of trials using the resulting score. Sample size required to detect a fixed percentage slowing in atrophy in a two-year clinical trial with equal allocation of subjects across arms and 90% power was calculated for the PSTC and optimal composite surrogate biomarker endpoints. The optimal composite endpoint required 38% fewer subjects to detect the same percent slowing in atrophy than required by the left PSTC endpoint. Optimal composites can increase the power of clinical trials and increase the probability that smaller trials are informative, an observation especially relevant for PPA, but also for related neurodegenerative disorders including Alzheimer's disease.

  16. A randomized trial of enhanced HIV risk reduction and vaccine trial education interventions among HIV-negative, high-risk women who use non-injection drugs: The UNITY Study

    PubMed Central

    Koblin, Beryl A.; Bonner, Sebastian; Hoover, Donald R.; Xu, Guozhen; Lucy, Debbie; Fortin, Princess; Putnam, Sara; Latka, Mary H.

    2014-01-01

    Background Limited data are available on interventions to reduce sexual risk behaviors and increase knowledge of HIV vaccine trial concepts in high risk populations eligible to participate in HIV vaccine efficacy trials. Methods The UNITY Study was a two-arm randomized trial to determine the efficacy of enhanced HIV risk reduction and vaccine trial education interventions to reduce the occurrence of unprotected vaginal sex acts and increase HIV vaccine trial knowledge among 311 HIV-negative non-injection drug using women. The enhanced vaccine education intervention using pictures along with application vignettes and enhanced risk reduction counseling consisting of three one-on-one counseling sessions were compared to standard conditions. Follow-up visits at one week and one, six and twelve months after randomization included HIV testing and assessment of outcomes. Results During follow up, the percent of women reporting sexual risk behaviors declined significantly, but did not differ significantly by study arm. Knowledge of HIV vaccine trial concepts significantly increased but did not significantly differ by study arm. Concepts about HIV vaccine trials not adequately addressed by either condition included those related to testing a vaccine for both efficacy and safety, guarantees about participation in future vaccine trials, assurances of safety, medical care, and assumptions about any protective effect of a test vaccine. Conclusions Further research is needed to boost educational efforts and strengthen risk reduction counseling among high-risk non-injection drug using women. PMID:20190585

  17. Methodological issues with adaptation of clinical trial design.

    PubMed

    Hung, H M James; Wang, Sue-Jane; O'Neill, Robert T

    2006-01-01

    Adaptation of clinical trial design generates many issues that have not been resolved for practical applications, though statistical methodology has advanced greatly. This paper focuses on some methodological issues. In one type of adaptation such as sample size re-estimation, only the postulated value of a parameter for planning the trial size may be altered. In another type, the originally intended hypothesis for testing may be modified using the internal data accumulated at an interim time of the trial, such as changing the primary endpoint and dropping a treatment arm. For sample size re-estimation, we make a contrast between an adaptive test weighting the two-stage test statistics with the statistical information given by the original design and the original sample mean test with a properly corrected critical value. We point out the difficulty in planning a confirmatory trial based on the crude information generated by exploratory trials. In regards to selecting a primary endpoint, we argue that the selection process that allows switching from one endpoint to the other with the internal data of the trial is not very likely to gain a power advantage over the simple process of selecting one from the two endpoints by testing them with an equal split of alpha (Bonferroni adjustment). For dropping a treatment arm, distributing the remaining sample size of the discontinued arm to other treatment arms can substantially improve the statistical power of identifying a superior treatment arm in the design. A common difficult methodological issue is that of how to select an adaptation rule in the trial planning stage. Pre-specification of the adaptation rule is important for the practicality consideration. Changing the originally intended hypothesis for testing with the internal data generates great concerns to clinical trial researchers.

  18. Region 10: Idaho Northern Ada County Adequate Letter (6/21/2013)

    EPA Pesticide Factsheets

    EPA approves motor vehicle emissions budget in the Northern Ada County PM10 State Implementation Plan, Maintenance Plan: Ten-Year Update for PM10 national ambient air quality standard, adequate for transportation conformity purposes.

  19. Increased calcium absorption from synthetic stable amorphous calcium carbonate: Double-blind randomized crossover clinical trial in post-menopausal women

    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...

  20. Challenging Assumptions About African American Participation in Alzheimer Disease Trials.

    PubMed

    Kennedy, Richard E; Cutter, Gary R; Wang, Guoqiao; Schneider, Lon S

    2017-10-01

    The authors investigated potential effects of increased African American participation in Alzheimer disease (AD) and mild cognitive impairment (MCI) clinical trials by examining differences in comorbid conditions and treatment outcome affecting trial design. Using a meta-database of 18 studies from the Alzheimer's Disease Cooperative Study and the Alzheimer's Disease Neuroimaging Initiative, a cohort of 5,164 subjects were included for whom there were baseline demographic data and information on comorbid disorders, grouped by organ system. Meta-analysis was used to compare prevalence of comorbidities, dropouts, and rates of change on the cognitive subscale of the Alzheimer's Disease Assessment Scale by race. Clinical trial scenarios similar to recent therapeutic trials were simulated to determine effects of increased African American participation on statistical power. Approximately 7% of AD, 4% of MCI, and 11% of normal participants were African American. African American subjects had higher prevalence of cardiovascular disorders (odds ratio: 2.10; 95% confidence interval [CI]: 1.71-2.57) and higher rate of dropouts (odds ratio: 1.60; 95% CI: 1.15-2.21) compared with whites but lower rates of other disorders. There were no significant differences in rate of progression (-0.862 points/year; 95% CI: -1.89 to 0.162) by race and little effect on power in simulated trials with sample sizes similar to current AD trial designs. Increasing African American participation in AD clinical trials will require adaptation of trial protocols to address comorbidities and dropouts. However, increased diversity is unlikely to negatively affect trial outcomes and should be encouraged to promote generalizability of trial results. Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  1. Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School

    PubMed Central

    Miciak, Jeremy; Stuebing, Karla K.; Vaughn, Sharon; Roberts, Greg; Barth, Amy Elizabeth; Fletcher, Jack M.

    2016-01-01

    No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders (n = 77) and inadequate responders who fell below criteria in (a) comprehension (n = 54); (b) fluency (n = 45); and (c) decoding, fluency, and comprehension (DFC; n = 45). These students received measures of phonological awareness, listening comprehension, rapid naming, processing speed, verbal knowledge, and nonverbal reasoning. Multivariate comparisons showed a significant Group-by-Task interaction: the comprehension-impaired group demonstrated primary difficulties with verbal knowledge and listening comprehension, the DFC group with phonological awareness, and the fluency-impaired group with phonological awareness and rapid naming. A series of regression models investigating whether responder status explained unique variation in cognitive skills yielded largely null results consistent with a continuum of severity associated with level of reading impairment, with no evidence for qualitative differences in the cognitive attributes of adequate and inadequate responders. PMID:28579668

  2. Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School.

    PubMed

    Miciak, Jeremy; Stuebing, Karla K; Vaughn, Sharon; Roberts, Greg; Barth, Amy Elizabeth; Fletcher, Jack M

    2014-12-01

    No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders ( n = 77) and inadequate responders who fell below criteria in (a) comprehension ( n = 54); (b) fluency ( n = 45); and (c) decoding, fluency, and comprehension (DFC; n = 45). These students received measures of phonological awareness, listening comprehension, rapid naming, processing speed, verbal knowledge, and nonverbal reasoning. Multivariate comparisons showed a significant Group-by-Task interaction: the comprehension-impaired group demonstrated primary difficulties with verbal knowledge and listening comprehension, the DFC group with phonological awareness, and the fluency-impaired group with phonological awareness and rapid naming. A series of regression models investigating whether responder status explained unique variation in cognitive skills yielded largely null results consistent with a continuum of severity associated with level of reading impairment, with no evidence for qualitative differences in the cognitive attributes of adequate and inadequate responders.

  3. 42 CFR 413.24 - Adequate cost data and cost finding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... familiar with the laws and regulations regarding the provision of health care services, and that the... 42 Public Health 2 2013-10-01 2013-10-01 false Adequate cost data and cost finding. 413.24 Section 413.24 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  4. 42 CFR 413.24 - Adequate cost data and cost finding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... familiar with the laws and regulations regarding the provision of health care services, and that the... 42 Public Health 2 2012-10-01 2012-10-01 false Adequate cost data and cost finding. 413.24 Section 413.24 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  5. 42 CFR 438.207 - Assurances of adequate capacity and services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... enrollment in its service area in accordance with the State's standards for access to care under this subpart... 42 Public Health 4 2014-10-01 2014-10-01 false Assurances of adequate capacity and services. 438.207 Section 438.207 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

  6. 42 CFR 438.207 - Assurances of adequate capacity and services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... enrollment in its service area in accordance with the State's standards for access to care under this subpart... 42 Public Health 4 2011-10-01 2011-10-01 false Assurances of adequate capacity and services. 438.207 Section 438.207 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

  7. 42 CFR 438.207 - Assurances of adequate capacity and services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... enrollment in its service area in accordance with the State's standards for access to care under this subpart... 42 Public Health 4 2012-10-01 2012-10-01 false Assurances of adequate capacity and services. 438.207 Section 438.207 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

  8. 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...

  9. Switching power supply

    DOEpatents

    Mihalka, A.M.

    1984-06-05

    The invention is a repratable capacitor charging, switching power supply. A ferrite transformer steps up a dc input. The transformer primary is in a full bridge configuration utilizing power MOSFETs as the bridge switches. The transformer secondary is fed into a high voltage, full wave rectifier whose output is connected directly to the energy storage capacitor. The transformer is designed to provide adequate leakage inductance to limit capacitor current. The MOSFETs are switched to the variable frequency from 20 to 50 kHz to charge a capacitor from 0.6 kV. The peak current in a transformer primary and secondary is controlled by increasing the pulse width as the capacitor charges. A digital ripple counter counts pulses and after a preselected desired number is reached an up-counter is clocked.

  10. Power and money in cluster randomized trials: when is it worth measuring a covariate?

    PubMed

    Moerbeek, Mirjam

    2006-08-15

    The power to detect a treatment effect in cluster randomized trials can be increased by increasing the number of clusters. An alternative is to include covariates into the regression model that relates treatment condition to outcome. In this paper, formulae are derived in order to evaluate both strategies on basis of their costs. It is shown that the strategy that uses covariates is more cost-efficient in detecting a treatment effect when the costs to measure these covariates are small and the correlation between the covariates and outcome is sufficiently large. The minimum required correlation depends on the cluster size, and the costs to recruit a cluster and to measure the covariate, relative to the costs to recruit a person. Measuring a covariate that varies at the person level only is recommended when cluster sizes are small and the costs to recruit and measure a cluster are large. Measuring a cluster level covariate is recommended when cluster sizes are large and the costs to recruit and measure a cluster are small. An illustrative example shows the use of the formulae in a practical setting. Copyright 2006 John Wiley & Sons, Ltd.

  11. 48 CFR 52.216-29 - Time-and-Materials/Labor-Hour Proposal Requirements-Non-Commercial Item Acquisition With Adequate...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-Hour Proposal Requirements-Non-Commercial Item Acquisition With Adequate Price Competition. 52.216-29... Proposal Requirements—Non-Commercial Item Acquisition With Adequate Price Competition (FEB 2007) (a) The... Time-and-Materials/Labor-Hour Proposal Requirements—Non-Commercial Item Acquisition With Adequate Price...

  12. Split-mouth design in Paediatric Dentistry clinical trials.

    PubMed

    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.

  13. Low-power laser therapy for carpal tunnel syndrome: effective optical power

    PubMed Central

    Chen, Yan; Zhao, Cheng-qiang; Ye, Gang; Liu, Can-dong; Xu, Wen-dong

    2016-01-01

    Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome, although its efficacy has been a long-standing controversy. The laser parameters in low-power laser therapy are closely related to the laser effect on human tissue. To evaluate the efficacy of low-power laser therapy, laser parameters should be accurately measured and controlled, which has been ignored in previous clinical trials. Here, we report the measurement of the effective optical power of low-power laser therapy for carpal tunnel syndrome. By monitoring the backside reflection and scattering laser power from human skin at the wrist, the effective laser power can be inferred. Using clinical measurements from 30 cases, we found that the effective laser power differed significantly among cases, with the measured laser reflection coefficient ranging from 1.8% to 54%. The reflection coefficient for 36.7% of these 30 cases was in the range of 10–20%, but for 16.7% of cases, it was higher than 40%. Consequently, monitoring the effective optical power during laser irradiation is necessary for the laser therapy of carpal tunnel syndrome. PMID:27630706

  14. Comparison of Time-to-First Event and Recurrent Event Methods in Randomized Clinical Trials.

    PubMed

    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

  15. 42 CFR 413.24 - Adequate cost data and cost finding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... provision of health care services, and that the services identified in this cost report were provided in... 42 Public Health 2 2014-10-01 2014-10-01 false Adequate cost data and cost finding. 413.24 Section 413.24 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  16. Effects of active/passive interventions on pain, anxiety, and quality of life in women with fibromyalgia: Randomized controlled pilot trial.

    PubMed

    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.

  17. [The human right to adequate food: an urban vision].

    PubMed

    Casemiro, Juliana Pereira; Valla, Victor Vincent; Guimarães, Maria Beatriz Lisboa

    2010-07-01

    The human right to adequate food is comprehended in two dimensions: being free of hunger and denutrition and having access to an adequate food. The urban context, in which the possession of food is done primarily through merchandising because of its strong consuming appealing, became a big challenge to debate this topic in poor districts today. Here we combine considerations of a qualitative study carried out in São João de Meriti, Rio de Janeiro State, joining leaders from Pastoral da Criança in focal group sessions. The unemployment, the sub-employment and the difficulty in reaching the public health system, the social assistance and basic sanitation were presented as the major obstacles to bring into effect the human right to food. It was possible to determine that, among the strategies to fight the poverty and hunger, a big highlight is the establishment of mutual help mechanisms. The social support, generosity and religiousness were presented as the most important categories among the thoughts of the leaders. Facing a reality in which poverty and hunger appear as something inherent or become a mechanism of change during elections, the issue of the clienteles appears as a huge concern and challenge for those leaders.

  18. Which Food Security Determinants Predict Adequate Vegetable Consumption among Rural Western Australian Children?

    PubMed Central

    Godrich, Stephanie L.; Lo, Johnny; Davies, Christina R.; Darby, Jill; Devine, Amanda

    2017-01-01

    Improving the suboptimal vegetable consumption among the majority of Australian children is imperative in reducing chronic disease risk. The objective of this research was to determine whether there was a relationship between food security determinants (FSD) (i.e., food availability, access, and utilisation dimensions) and adequate vegetable consumption among children living in regional and remote Western Australia (WA). Caregiver-child dyads (n = 256) living in non-metropolitan/rural WA completed cross-sectional surveys that included questions on FSD, demographics and usual vegetable intake. A total of 187 dyads were included in analyses, which included descriptive and logistic regression analyses via IBM SPSS (version 23). A total of 13.4% of children in this sample had adequate vegetable intake. FSD that met inclusion criteria (p ≤ 0.20) for multivariable regression analyses included price; promotion; quality; location of food outlets; variety of vegetable types; financial resources; and transport to outlets. After adjustment for potential demographic confounders, the FSD that predicted adequate vegetable consumption were, variety of vegetable types consumed (p = 0.007), promotion (p = 0.017), location of food outlets (p = 0.027), and price (p = 0.043). Food retail outlets should ensure that adequate varieties of vegetable types (i.e., fresh, frozen, tinned) are available, vegetable messages should be promoted through food retail outlets and in community settings, towns should include a range of vegetable purchasing options, increase their reliance on a local food supply and increase transport options to enable affordable vegetable purchasing. PMID:28054955

  19. Which Food Security Determinants Predict Adequate Vegetable Consumption among Rural Western Australian Children?

    PubMed

    Godrich, Stephanie L; Lo, Johnny; Davies, Christina R; Darby, Jill; Devine, Amanda

    2017-01-03

    Improving the suboptimal vegetable consumption among the majority of Australian children is imperative in reducing chronic disease risk. The objective of this research was to determine whether there was a relationship between food security determinants (FSD) (i.e., food availability, access, and utilisation dimensions) and adequate vegetable consumption among children living in regional and remote Western Australia (WA). Caregiver-child dyads ( n = 256) living in non-metropolitan/rural WA completed cross-sectional surveys that included questions on FSD, demographics and usual vegetable intake. A total of 187 dyads were included in analyses, which included descriptive and logistic regression analyses via IBM SPSS (version 23). A total of 13.4% of children in this sample had adequate vegetable intake. FSD that met inclusion criteria ( p ≤ 0.20) for multivariable regression analyses included price; promotion; quality; location of food outlets; variety of vegetable types; financial resources; and transport to outlets. After adjustment for potential demographic confounders, the FSD that predicted adequate vegetable consumption were, variety of vegetable types consumed ( p = 0.007), promotion ( p = 0.017), location of food outlets ( p = 0.027), and price ( p = 0.043). Food retail outlets should ensure that adequate varieties of vegetable types (i.e., fresh, frozen, tinned) are available, vegetable messages should be promoted through food retail outlets and in community settings, towns should include a range of vegetable purchasing options, increase their reliance on a local food supply and increase transport options to enable affordable vegetable purchasing.

  20. Solar powered oxygen systems in remote health centers in Papua New Guinea: a large scale implementation effectiveness trial.

    PubMed

    Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa'avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa

    2017-06-01

    Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before-and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and measurement of processes and

  1. Solar powered oxygen systems in remote health centers in Papua New Guinea: a large scale implementation effectiveness trial

    PubMed Central

    Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa’avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa

    2017-01-01

    Background Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. Methods We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before–and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. Results The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and

  2. Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes.

    PubMed

    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.

  3. European Marketing Authorizations Granted Based on a Single Pivotal Clinical Trial: The Rule or the Exception?

    PubMed

    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.

  4. Implantable radio frequency identification sensors: wireless power and communication.

    PubMed

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

  5. Advancing the evidence base in cancer: psychosocial multicenter trials

    PubMed Central

    2012-01-01

    Background The diagnosis and treatment of cancer is associated with significant distress and psychosocial morbidity. Although psychosocial interventions have been developed in an attempt to improve psychosocial outcomes in cancer patients and survivors, there is continued debate about whether there is adequate high-level evidence to establish the effectiveness of these interventions. The evidence base is limited as a result of numerous challenges faced by those attempting to conduct psychosocial intervention trials within the health system. Barriers include insufficient participant recruitment, difficulty generalizing from single-trial studies, difficulty in building and managing research teams with multidisciplinary expertise, lack of research design expertise and a lack of incentives for researchers conducting intervention research. To strengthen the evidence base, more intervention studies employing methodologically rigorous research designs are necessary. Methods In order to advance the evidence base of interventions designed to improve psychosocial outcomes for cancer patients and survivors, we propose the formation of a collaborative trials group that conducts multicenter trials to test the effectiveness of such interventions. Results Establishment of such a group would improve the quality of the evidence base in psychosocial research in cancer patients, by increasing support for conducting intervention research and providing intervention research training opportunities. A multidisciplinary collaborative group conducting multicenter trials would have the capacity to overcome many of the barriers that currently exist. Conclusions A stronger evidence base is necessary to identify effective psychosocial interventions for cancer patients. The proposed formation of a psycho-oncology collaborative trials group that conducts multicenter trials to test the effectiveness of psychosocial interventions would assist in achieving this outcome. PMID:22992443

  6. Fortuitous phenomena: on complexity, pragmatic randomised controlled trials, and knowledge for evidence-based practice.

    PubMed

    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.

  7. Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice

    PubMed Central

    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

  8. Prestimulus alpha power predicts fidelity of sensory encoding in perceptual decision making.

    PubMed

    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.

  9. Designs and adaptive analysis plans for pivotal clinical trials of therapeutics and companion diagnostics.

    PubMed

    Simon, Richard

    2008-06-01

    Developments in genomics and biotechnology provide unprecedented opportunities for the development of effective therapeutics and companion diagnostics for matching the right drug to the right patient. Effective co-development involves many new challenges with increased opportunity for success as well as delay and failure. Clinical trial designs and adaptive analysis plans for the prospective design of pivotal trials of new therapeutics and companion diagnostics are reviewed. Effective co-development requires careful prospective planning of the design and analysis strategy for pivotal clinical trials. Randomized clinical trials continue to be important for evaluating the effectiveness of new treatments, but the target populations for analysis should be prospectively specified based on the companion diagnostic. Post hoc analyses of traditionally designed randomized clinical trials are often deeply problematic. Clear separation is generally required of the data used for developing the diagnostic test, including their threshold of positivity, from the data used for evaluating treatment effectiveness in subsets determined by the test. Adaptive analysis can be used to provide flexibility to the analysis but the use of such methods requires careful planning and prospective definition in order to assure that the pivotal trial adequately limits the chance of erroneous conclusions.

  10. Patients' attitudes and preferences about participation and recruitment strategies in clinical trials.

    PubMed

    Sood, Amit; Prasad, Kavita; Chhatwani, Laveena; Shinozaki, Eri; Cha, Stephen S; Loehrer, Laura L; Wahner-Roedler, Dietlind L

    2009-03-01

    To assess attitudes of patients about participation in clinical trials. This is a self-report survey of 400 patients who underwent general medical evaluations between September and November 2006 at a tertiary care academic medical center in Rochester, MN. We measured knowledge of access to clinical trials, attitudes toward participation, recruitment preferences, and beliefs about research integrity. Of 485 consecutive patients, 400 (82%) completed the survey. Previous participation in clinical trials was reported by 112 patients (28%). Most were unaware of online information about clinical trials (330 [82%]), were satisfied with their current knowledge (233 [58%]), expected their treating physician to inform them about current trials (304 [76%]), and showed equal interest in participating in conventional or complementary intervention trials (174 [44%]). Of the 400 respondents, 321 (80%) found it appropriate to be contacted by mail and 253 (63%) by telephone regarding study participation. Most patients (364 [91%]) wanted to be informed about research findings or else would not participate in future clinical trials (272 [68%]). The most frequently expected compensation was free parking (234 [58%]). Most thought that their safety (373 [93%]) and privacy (376 [94%]) would be guarded. Patients are interested in participating in clinical trials but commonly lack adequate information. If patients received more information (through their treating physicians), enrollment might improve. This single-site study has limited generalizability. Future studies involving a diverse group of patients from a broader geographic distribution will help provide more definitive results.

  11. RELIABILITY OF THE ONE REPETITION-MAXIMUM POWER CLEAN TEST IN ADOLESCENT ATHLETES

    PubMed Central

    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

  12. Using the MEDiPORT humanoid robot to reduce procedural pain and distress in children with cancer: A pilot randomized controlled trial.

    PubMed

    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.

  13. Building 865 Hypersonic Wind Tunnel Power System Analysis

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

    Schneider, Larry X.

    2015-02-01

    This report documents the characterization and analysis of a high current power supply for the building 865 Hypersonic Wind Tunnel at Sandia National Laboratories. The system described in this report became operational in 2013, replacing the original 1968 system which employed an induction voltage regulator. This analysis and testing was completed to help the parent organization understand why an updated and redesigned power system was not delivering adequate power to resistive heater elements in the HWT. This analysis led to an improved understanding of the design and operation of the revised 2013 power supply system and identifies several reasons themore » revised system failed to achieve the performance of the original power supply installation. Design modifications to improve the performance of this system are discussed.« less

  14. Enhancing clinical evidence by proactively building quality into clinical trials.

    PubMed

    Meeker-O'Connell, Ann; Glessner, Coleen; Behm, Mark; Mulinde, Jean; Roach, Nancy; Sweeney, Fergus; Tenaerts, Pamela; Landray, Martin J

    2016-08-01

    Stakeholders across the clinical trial enterprise have expressed concern that the current clinical trial enterprise is unsustainable. The cost and complexity of trials have continued to increase, threatening our ability to generate reliable evidence essential for making appropriate decisions concerning the benefits and harms associated with clinical interventions. Overcoming this inefficiency rests on improving protocol design, trial planning, and quality oversight. The Clinical Trials Transformation Initiative convened a project to evaluate methods to prospectively build quality into the scientific and operational design of clinical trials ("quality-by-design"), such that trials are feasible to conduct and important errors are prevented rather than remediated. A working group evaluated aspects of trial design and oversight and developed the Clinical Trials Transformation Initiative quality-by-design principles document, outlining a series of factors generally relevant to the reliability of trial conclusions and to patient safety. These principles were then applied and further refined during a series of hands-on workshops to evaluate their utility in facilitating proactive, cross-functional dialogue, and decision-making about trial design and planning. Following these workshops, independent qualitative interviews were conducted with 19 workshop attendees to explore the potential challenges for implementing a quality-by-design approach to clinical trials. The Clinical Trials Transformation Initiative project team subsequently developed recommendations and an online resource guide to support implementation of this approach. The Clinical Trials Transformation Initiative quality-by-design principles provide a framework for assuring that clinical trials adequately safeguard participants and provide reliable information on which to make decisions on the effects of treatments. The quality-by-design workshops highlighted the value of active discussions incorporating the

  15. Safe delivery of optical power from space.

    PubMed

    Smith, M; Fork, R L; Cole, S

    2001-05-07

    More than a billion gigawatts of sunlight pass through the area extending from Earth out to geostationary orbit. A small fraction of this clean renewable power appears more than adequate to satisfy the projected needs of Earth, and of human exploration and development of space far into the future. Recent studies suggest safe and efficient access to this power can be achieved within 10 to 40 years. Light, enhanced in spatial and temporal coherence, as compared to natural sunlight, offers a means, and probably the only practical means, of usefully transmitting this power to Earth. We describe safety standards for satellite constellations and Earth based sites designed, respectively, to transmit, and receive this power. The spectral properties, number of satellites, and angle subtended at Earth that are required for safe delivery are identified and discussed.

  16. Leveraging contact network structure in the design of cluster randomized trials.

    PubMed

    Harling, Guy; Wang, Rui; Onnela, Jukka-Pekka; De Gruttola, Victor

    2017-02-01

    In settings like the Ebola epidemic, where proof-of-principle trials have provided evidence of efficacy but questions remain about the effectiveness of different possible modes of implementation, it may be useful to conduct trials that not only generate information about intervention effects but also themselves provide public health benefit. Cluster randomized trials are of particular value for infectious disease prevention research by virtue of their ability to capture both direct and indirect effects of intervention, the latter of which depends heavily on the nature of contact networks within and across clusters. By leveraging information about these networks-in particular the degree of connection across randomized units, which can be obtained at study baseline-we propose a novel class of connectivity-informed cluster trial designs that aim both to improve public health impact (speed of epidemic control) and to preserve the ability to detect intervention effects. We several designs for cluster randomized trials with staggered enrollment, in each of which the order of enrollment is based on the total number of ties (contacts) from individuals within a cluster to individuals in other clusters. Our designs can accommodate connectivity based either on the total number of external connections at baseline or on connections only to areas yet to receive the intervention. We further consider a "holdback" version of the designs in which control clusters are held back from re-randomization for some time interval. We investigate the performance of these designs in terms of epidemic control outcomes (time to end of epidemic and cumulative incidence) and power to detect intervention effect, by simulating vaccination trials during an SEIR-type epidemic outbreak using a network-structured agent-based model. We compare results to those of a traditional Stepped Wedge trial. In our simulation studies, connectivity-informed designs lead to a 20% reduction in cumulative incidence

  17. Macronutrient supplementation for malnourished HIV-infected adults: a review of the evidence in resource-adequate and resource-constrained settings.

    PubMed

    Koethe, John R; Chi, Benjamin H; Megazzini, Karen M; Heimburger, Douglas C; Stringer, Jeffrey S A

    2009-09-01

    Access to antiretroviral therapy (ART) for human immunodeficiency virus (HIV) infection has expanded rapidly throughout sub-Saharan Africa, but malnutrition and food insecurity have emerged as major barriers to the success of ART programs. Protein-calorie malnutrition (a common form of malnutrition in the region) hastens HIV disease progression, and food insecurity is a barrier to medication adherence. Analyses of patient outcomes have identified a low body mass index after the start of ART as an independent predictor of early mortality, but the causes of a low body mass index are multifactorial (eg, normal anthropometric variation, chronic inadequate food intake, and/or wasting associated with HIV infection and other infectious diseases). Although there is much information on population-level humanitarian food assistance, few data exist to measure the effectiveness of macronutrient supplementation or to identify individuals most likely to benefit. In this report, we review the current evidence supporting macronutrient supplementation for HIV-infected adults, we report on clinical trials in resource-adequate and resource-constrained settings, and we highlight priority areas for future research.

  18. 45 CFR 1159.15 - Who has the responsibility for maintaining adequate technical, physical, and security safeguards...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... disclosure or destruction of manual and automatic record systems. These security safeguards shall apply to... use of records contained in a system of records are adequately trained to protect the security and... adequate technical, physical, and security safeguards to prevent unauthorized disclosure or destruction of...

  19. Transparency of outcome reporting and trial registration of randomized controlled trials in top psychosomatic and behavioral health journals: A systematic review.

    PubMed

    Milette, Katherine; Roseman, Michelle; Thombs, Brett D

    2011-03-01

    The most reliable evidence for evaluating healthcare interventions comes from well-designed and conducted randomized controlled trials (RCTs). The extent to which published RCTs reflect the efficacy of interventions, however, depends on the completeness and accuracy of published results. The Consolidated Standards of Reporting Trials statement, initially developed in 1996, provides guidelines intended to improve the transparency of published RCT reports. A policy of the International Committee of Medical Journal Editors, initiated in 2005, requires clinical trials published in member journals to be registered in publicly accessible registries prior to patient enrollment. The objective of this study was to assess the clarity of outcome reporting, proportion of registered trials, and adequacy of outcome registration in RCTs published in top behavioral health journals. Eligible studies were primary or secondary reports of RCTs published in Annals of Behavioral Medicine, Health Psychology, Journal of Psychosomatic Research, and Psychosomatic Medicine from January 2008 to September 2009. Data were extracted for each study on adequacy of outcome reporting and registration. Of 63 articles reviewed, only 25 (39.7%) had adequately declared primary or secondary outcomes, whereas 38 (60.3%) had multiple primary outcomes or did not define outcomes. Only 13 studies (20.6%) were registered. Only 1 study registered sufficiently precise outcome information to compare with published outcomes, and registered and published outcomes were discrepant in that study. Greater attention to outcome reporting and trial registration by researchers, peer reviewers, and journal editors will increase the likelihood that effective behavioral health interventions are readily identified and made available to patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Are reports of randomized controlled trials improving over time? A systematic review of 284 articles published in high-impact general and specialized medical journals.

    PubMed

    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.

  1. Applying Probabilistic Decision Models to Clinical Trial Design

    PubMed Central

    Smith, Wade P; Phillips, Mark H

    2018-01-01

    Clinical trial design most often focuses on a single or several related outcomes with corresponding calculations of statistical power. We consider a clinical trial to be a decision problem, often with competing outcomes. Using a current controversy in the treatment of HPV-positive head and neck cancer, we apply several different probabilistic methods to help define the range of outcomes given different possible trial designs. Our model incorporates the uncertainties in the disease process and treatment response and the inhomogeneities in the patient population. Instead of expected utility, we have used a Markov model to calculate quality adjusted life expectancy as a maximization objective. Monte Carlo simulations over realistic ranges of parameters are used to explore different trial scenarios given the possible ranges of parameters. This modeling approach can be used to better inform the initial trial design so that it will more likely achieve clinical relevance. PMID:29888075

  2. National Cancer Institute's Precision Medicine Initiatives for the new National Clinical Trials Network.

    PubMed

    Abrams, Jeffrey; Conley, Barbara; Mooney, Margaret; Zwiebel, James; Chen, Alice; Welch, John J; Takebe, Naoko; Malik, Shakun; McShane, Lisa; Korn, Edward; Williams, Mickey; Staudt, Louis; Doroshow, James

    2014-01-01

    The promise of precision medicine will only be fully realized if the research community can adapt its clinical trials methodology to study molecularly characterized tumors instead of the traditional histologic classification. Such trials will depend on adequate tissue collection, availability of quality controlled, high throughput molecular assays, and the ability to screen large numbers of tumors to find those with the desired molecular alterations. The National Cancer Institute's (NCI) new National Clinical Trials Network (NCTN) is well positioned to conduct such trials. The NCTN has the ability to seamlessly perform ethics review, register patients, manage data, and deliver investigational drugs across its many sites including both in cities and rural communities, academic centers, and private practices. The initial set of trials will focus on different questions: (1) Exceptional Responders Initiative-why do a minority of patients with solid tumors or lymphoma respond very well to some drugs even if the majority do not?; (2) NCI MATCH trial-can molecular markers predict response to targeted therapies in patients with advanced cancer resistant to standard treatment?; (3) ALCHEMIST trial-will targeted epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) inhibitors improve survival for adenocarcinoma of the lung in the adjuvant setting?; and (4) Lung Cancer Master Protocol trial for advanced squamous cell lung cancer-is there an advantage to developing drugs for small subsets of molecularly characterized tumors in a single, multiarm trial design? These studies will hopefully spawn a new era of treatment trials that will carefully select the tumors that may respond best to investigational therapy.

  3. An introduction to multiplicity issues in clinical trials: the what, why, when and how.

    PubMed

    Li, Guowei; Taljaard, Monica; Van den Heuvel, Edwin R; Levine, Mitchell Ah; Cook, Deborah J; Wells, George A; Devereaux, Philip J; Thabane, Lehana

    2017-04-01

    In clinical trials it is not uncommon to face a multiple testing problem which can have an impact on both type I and type II error rates, leading to inappropriate interpretation of trial results. Multiplicity issues may need to be considered at the design, analysis and interpretation stages of a trial. The proportion of trial reports not adequately correcting for multiple testing remains substantial. The purpose of this article is to provide an introduction to multiple testing issues in clinical trials, and to reduce confusion around the need for multiplicity adjustments. We use a tutorial, question-and-answer approach to address the key issues of why, when and how to consider multiplicity adjustments in trials. We summarize the relevant circumstances under which multiplicity adjustments ought to be considered, as well as options for carrying out multiplicity adjustments in terms of trial design factors including Population, Intervention/Comparison, Outcome, Time frame and Analysis (PICOTA). Results are presented in an easy-to-use table and flow diagrams. Confusion about multiplicity issues can be reduced or avoided by considering the potential impact of multiplicity on type I and II errors and, if necessary pre-specifying statistical approaches to either avoid or adjust for multiplicity in the trial protocol or analysis plan. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  4. Good isometric and isokinetic power restoration after distal biceps tendon repair with anchors.

    PubMed

    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.

  5. Solar power satellite system definition study. Part 2, volume 4: Microwave power transmission systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A slotted waveguide planar array was established as the baseline design for the spaceborne transmitter antenna. Key aspects of efficient energy conversion at both ends of the power transfer link were analyzed and optimized alternate approaches in the areas of antenna and tube design are discussed. An integrated design concept was developed which meets design requirements, observes structural and thermal constraints, exhibits good performance and was developed in adequate depth to permit cost estimating at the subsystem/component level.

  6. Incorporation of stochastic engineering models as prior information in Bayesian medical device trials.

    PubMed

    Haddad, Tarek; Himes, Adam; Thompson, Laura; Irony, Telba; Nair, Rajesh

    2017-01-01

    Evaluation of medical devices via clinical trial is often a necessary step in the process of bringing a new product to market. In recent years, device manufacturers are increasingly using stochastic engineering models during the product development process. These models have the capability to simulate virtual patient outcomes. This article presents a novel method based on the power prior for augmenting a clinical trial using virtual patient data. To properly inform clinical evaluation, the virtual patient model must simulate the clinical outcome of interest, incorporating patient variability, as well as the uncertainty in the engineering model and in its input parameters. The number of virtual patients is controlled by a discount function which uses the similarity between modeled and observed data. This method is illustrated by a case study of cardiac lead fracture. Different discount functions are used to cover a wide range of scenarios in which the type I error rates and power vary for the same number of enrolled patients. Incorporation of engineering models as prior knowledge in a Bayesian clinical trial design can provide benefits of decreased sample size and trial length while still controlling type I error rate and power.

  7. Critical Assessment of the Foundations of Power Transmission and Distribution Reliability Metrics and Standards.

    PubMed

    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.

  8. A Brief History of Placebos and Clinical Trials in Psychiatry

    PubMed Central

    Shorter, Edward

    2013-01-01

    The history of placebos in psychiatry can be understood only in the context of randomized controlled trials (RCTs). Placebo treatments are as old as medicine itself, and are particularly effective in dealing with psychosomatic symptoms. In psychiatry, placebos have mainly been featured in clinical drug trials. The earliest controlled trial in psychiatry (not involving drugs) occurred in 1922, followed by the first crossover studies during the 1930s. Meanwhile the concept of randomization was developed during the interwar years by British statistician Ronald A Fisher, and introduced in 3 trials of tuberculosis drugs between 1947 and 1951. These classic studies established the RCT as the gold standard in pharmaceutical trials, and its status was cemented during the mid-1950s. Nevertheless, while the placebo became established as a standard measure of drug action, placebo treatments became stigmatized as unethical. This is unfortunate, as they constitute one of the most powerful therapies in psychiatry. In recent years, moreover, the dogma of the placebo-controlled trial as the only acceptable data for drug licensing is also being increasingly discredited. This backlash has had 2 sources: one is the recognition that the US Food and Drug Administration has been too lax in permitting trials controlled with placebos alone, rather than also using an active agent as a test of comparative efficacy. In addition, there is evidence that in the hands of the pharmaceutical industry, the scientific integrity of RCTs themselves has been degraded into a marketing device. The once-powerful placebo is thus threatened with extinction. PMID:21507275

  9. A brief history of placebos and clinical trials in psychiatry.

    PubMed

    Shorter, Edward

    2011-04-01

    The history of placebos in psychiatry can be understood only in the context of randomized controlled trials (RCTs). Placebo treatments are as old as medicine itself, and are particularly effective in dealing with psychosomatic symptoms. In psychiatry, placebos have mainly been featured in clinical drug trials. The earliest controlled trial in psychiatry (not involving drugs) occurred in 1922, followed by the first crossover studies during the 1930s. Meanwhile the concept of randomization was developed during the interwar years by British statistician Ronald A Fisher, and introduced in 3 trials of tuberculosis drugs between 1947 and 1951. These classic studies established the RCT as the gold standard in pharmaceutical trials, and its status was cemented during the mid-1950s. Nevertheless, while the placebo became established as a standard measure of drug action, placebo treatments became stigmatized as unethical. This is unfortunate, as they constitute one of the most powerful therapies in psychiatry. In recent years, moreover, the dogma of the placebo-controlled trial as the only acceptable data for drug licensing is also being increasingly discredited. This backlash has had 2 sources: one is the recognition that the US Food and Drug Administration has been too lax in permitting trials controlled with placebos alone, rather than also using an active agent as a test of comparative efficacy. In addition, there is evidence that in the hands of the pharmaceutical industry, the scientific integrity of RCTs themselves has been degraded into a marketing device. The once-powerful placebo is thus threatened with extinction.

  10. A Randomized Controlled Trial of Compression Rates during Cardiopulmonary Resuscitation

    PubMed Central

    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

  11. Region 8: Colorado Lamar and Steamboat Springs Adequate Letter (11/12/2002)

    EPA Pesticide Factsheets

    This letter from EPA to Colorado Department of Public Health and Environment determined Lamar and Steamboat Springs particulate matter (PM10) maintenance plan for Motor Vehicle Emissions Budgets adequate for transportation conformity purposes

  12. 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...

  13. Selecting Power-Efficient Signal Features for a Low-Power Fall Detector.

    PubMed

    Wang, Changhong; Redmond, Stephen J; Lu, Wei; Stevens, Michael C; Lord, Stephen R; Lovell, Nigel H

    2017-11-01

    Falls are a serious threat to the health of older people. A wearable fall detector can automatically detect the occurrence of a fall and alert a caregiver or an emergency response service so they may deliver immediate assistance, improving the chances of recovering from fall-related injuries. One constraint of such a wearable technology is its limited battery life. Thus, minimization of power consumption is an important design concern, all the while maintaining satisfactory accuracy of the fall detection algorithms implemented on the wearable device. This paper proposes an approach for selecting power-efficient signal features such that the minimum desirable fall detection accuracy is assured. Using data collected in simulated falls, simulated activities of daily living, and real free-living trials, all using young volunteers, the proposed approach selects four features from a set of ten commonly used features, providing a power saving of 75.3%, while limiting the error rate of a binary classification decision tree fall detection algorithm to 7.1%.Falls are a serious threat to the health of older people. A wearable fall detector can automatically detect the occurrence of a fall and alert a caregiver or an emergency response service so they may deliver immediate assistance, improving the chances of recovering from fall-related injuries. One constraint of such a wearable technology is its limited battery life. Thus, minimization of power consumption is an important design concern, all the while maintaining satisfactory accuracy of the fall detection algorithms implemented on the wearable device. This paper proposes an approach for selecting power-efficient signal features such that the minimum desirable fall detection accuracy is assured. Using data collected in simulated falls, simulated activities of daily living, and real free-living trials, all using young volunteers, the proposed approach selects four features from a set of ten commonly used features, providing

  14. A Framework for Designing Cluster Randomized Trials with Binary Outcomes

    ERIC Educational Resources Information Center

    Spybrook, Jessaca; Martinez, Andres

    2011-01-01

    The purpose of this paper is to provide a frame work for approaching a power analysis for a CRT (cluster randomized trial) with a binary outcome. The authors suggest a framework in the context of a simple CRT and then extend it to a blocked design, or a multi-site cluster randomized trial (MSCRT). The framework is based on proportions, an…

  15. A cluster randomized trial of routine HIV-1 viral load monitoring in Zambia: study design, implementation, and baseline cohort characteristics.

    PubMed

    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.

  16. Assessing Cognitive Function in Bipolar Disorder: Challenges and Recommendations for Clinical Trial Design

    PubMed Central

    Burdick, Katherine E.; Ketter, Terence A.; Goldberg, Joseph F.; Calabrese, Joseph R.

    2015-01-01

    provided here as a preliminary guide for future trial design. Recommendations comprise exclusion of certain syndromal level comorbid diagnoses and current affective instability, restrictions on numbers and types of medications, and use of pre-screening assessment to ensure enrollment of subjects with adequate objective evidence of baseline cognitive impairment. CONCLUSIONS Clinical trials to address cognitive deficits in bipolar disorder face distinctive design challenges. As such trials move from proof-of-concept to confirmation of clinical efficacy, it will be important to incorporate distinctive design modifications to adequately address these challenges and increase the likelihood of demonstrating cognitive remediation effects. The field is now primed to address these challenges and a comprehensive effort to formalize best practice guidelines will be a critically important next step. PMID:25830456

  17. The Relieving Effects of BrainPower Advanced, a Dietary Supplement, in Older Adults with Subjective Memory Complaints: A Randomized, Double-Blind, Placebo-Controlled Trial.

    PubMed

    Zhu, Jingfen; Shi, Rong; Chen, Su; Dai, Lihua; Shen, Tian; Feng, Yi; Gu, Pingping; Shariff, Mina; Nguyen, Tuong; Ye, Yeats; Rao, Jianyu; Xing, Guoqiang

    2016-01-01

    Subjective memory complaints (SMCs) are common in older adults that can often predict further cognitive impairment. No proven effective agents are available for SMCs. The effect of BrainPower Advanced, a dietary supplement consisting of herbal extracts, nutrients, and vitamins, was evaluated in 98 volunteers with SMCs, averaging 67 years of age (47-88), in a randomized, double-blind, placebo-controlled trial. Subjective hypomnesis/memory loss (SML) and attention/concentration deficits (SAD) were evaluated before and after 12-week supplementation of BrainPower Advanced capsules (n = 47) or placebo (n = 51), using a 5-point memory questionnaire (1 = no/slight, 5 = severe). Objective memory function was evaluated using 3 subtests of visual/audio memory, abstraction, and memory recall that gave a combined total score. The BrainPower Advanced group had more cases of severe SML (severity ⩾ 3) (44/47) and severe SAD (43/47) than the placebo group (39/51 and 37/51, < 0.05, < 0.05, resp.) before the treatment. BrainPower Advanced intervention, however, improved a greater proportion of the severe SML (29.5%)(13/44) (P < 0.01) and SAD (34.9%)(15/43)(P < 0.01) than placebo (5.1% (2/39) and 13.5% (5/37), resp.). Thus, 3-month BrainPower Advanced supplementation appears to be beneficial to older adults with SMCs.

  18. Gaining power and precision by using model-based weights in the analysis of late stage cancer trials with substantial treatment switching.

    PubMed

    Bowden, Jack; Seaman, Shaun; Huang, Xin; White, Ian R

    2016-04-30

    In randomised controlled trials of treatments for late-stage cancer, it is common for control arm patients to receive the experimental treatment around the point of disease progression. This treatment switching can dilute the estimated treatment effect on overall survival and impact the assessment of a treatment's benefit on health economic evaluations. The rank-preserving structural failure time model of Robins and Tsiatis (Comm. Stat., 20:2609-2631) offers a potential solution to this problem and is typically implemented using the logrank test. However, in the presence of substantial switching, this test can have low power because the hazard ratio is not constant over time. Schoenfeld (Biometrika, 68:316-319) showed that when the hazard ratio is not constant, weighted versions of the logrank test become optimal. We present a weighted logrank test statistic for the late stage cancer trial context given the treatment switching pattern and working assumptions about the underlying hazard function in the population. Simulations suggest that the weighted approach can lead to large efficiency gains in either an intention-to-treat or a causal rank-preserving structural failure time model analysis compared with the unweighted approach. Furthermore, violation of the working assumptions used in the derivation of the weights only affects the efficiency of the estimates and does not induce bias or inflate the type I error rate. The weighted logrank test statistic should therefore be considered for use as part of a careful secondary, exploratory analysis of trial data affected by substantial treatment switching. ©2015 The Authors. Statistics inMedicine Published by John Wiley & Sons Ltd.

  19. Global shortage of neonatal and paediatric antibiotic trials: rapid review

    PubMed Central

    Thompson, Georgina; Barker, Charlotte I; Folgori, Laura; Bielicki, Julia A; Bradley, John S; Lutsar, Irja; Sharland, Mike

    2017-01-01

    Objectives There have been few clinical trials (CTs) on antibiotics that inform neonatal and paediatric drug labelling. The rate of unlicensed and off-label prescribing in paediatrics remains high. It is unclear whether the current neonatal and paediatric antibiotic research pipeline is adequate to inform optimal drug dosing. Using the ClinicalTrials.gov registry, this review aims to establish the current global status of antibiotic CTs in children up to 18 years of age. Methods Studies were identified using key word searches of the ClinicalTrials.gov registry and were manually filtered using prespecified inclusion/exclusion criteria. Results 76 registered open CTs of antibiotics in children were identified globally; 23 (30%) were recruiting newborns (only 8 (11%) included preterm neonates), 52 (68%) infants and toddlers, 58 (76%) children and 54 (71%) adolescents. The majority of registered trials were late phase (10 (15%) phase 3 and 23 (35%) phase 4/pharmacovigilance). Two-thirds were sponsored by non-profit organisations, compared with pharmaceutical companies (50 (66%) vs 26 (34%), respectively). A greater proportion of non-profit funded trials were efficacy-based strategic trials (n=34, 68%), in comparison with industry-led trials, which were most often focused on safety or pharmacokinetic data (n=17, 65%). Only 2 of the 37 antibiotics listed on the May 2016 Pew Charitable Trusts antibiotic development pipeline, currently being studied in adults, appear to be currently recruiting in open paediatric CTs. Conclusions This review highlights that very few paediatric antibiotic CTs are being conducted globally, especially in neonates. There is a striking disparity noted between antibiotic drug development programmes in adults and children. PMID:29030411

  20. Control groups in recent septic shock trials: a systematic review.

    PubMed

    Pettilä, Ville; Hjortrup, Peter Buhl; Jakob, Stephan M; Wilkman, Erika; Perner, Anders; Takala, Jukka

    2016-12-01

    The interpretation of septic shock trial data is profoundly affected by patients, control intervention, co-interventions and selected outcome measures. We evaluated the reporting of control groups in recent septic shock trials. We searched for original articles presenting randomized clinical trials (RCTs) in adult septic shock patients from 2006 to 2016. We included RCTs focusing on septic shock patients with at least two parallel groups and at least 50 patients in the control group. We selected and evaluated data items regarding patients, control group characteristics, and mortality outcomes, and calculated a data completeness score to provide an overall view of quality of reporting. A total of 24 RCTs were included (mean n = 287 patients and 71 % of eligible patients were randomized). Of the 24 studies, 14 (58 %) presented baseline data on vasopressors and 58 % the proportion of patients with elevated lactate values. Five studies (21 %) provided data to estimate the proportion of septic shock patients fulfilling the Sepsis-3 definition. The mean data completeness score was 19 out of 36 (range 8-32). Of 18 predefined control group characteristics, a mean of 8 (range 2-17) were reported. Only 2 (8 %) trials provided adequate data to confirm that their control group treatment represented usual care. Recent trials in septic shock provide inadequate data on the control group treatment and hemodynamic values. We propose a standardized trial dataset to be created and validated, comprising characteristics of patient population, interventions administered, hemodynamic values achieved, surrogate organ dysfunction, and mortality outcomes, to allow better analysis and interpretation of future trial results.

  1. A cluster randomised feasibility trial evaluating nutritional interventions in the treatment of malnutrition in care home adult residents.

    PubMed

    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

  2. State Implementation Plans (SIP): Submissions that EPA has Found Adequate or Inadequate

    EPA Pesticide Factsheets

    EPA/OTAQ’s State and Local Transportation Resources are for air quality and transportation government and community leaders. Information on state implementation plans (SIPs) that EPA has found either adequate or inadequate is provided here.

  3. Patients' Attitudes and Preferences About Participation and Recruitment Strategies in Clinical Trials

    PubMed Central

    Sood, Amit; Prasad, Kavita; Chhatwani, Laveena; Shinozaki, Eri; Cha, Stephen S.; Loehrer, Laura L.; Wahner-Roedler, Dietlind L.

    2009-01-01

    OBJECTIVE: To assess attitudes of patients about participation in clinical trials. PATIENTS AND METHODS: This is a self-report survey of 400 patients who underwent general medical evaluations between September and November 2006 at a tertiary care academic medical center in Rochester, MN. We measured knowledge of access to clinical trials, attitudes toward participation, recruitment preferences, and beliefs about research integrity. RESULTS: Of 485 consecutive patients, 400 (82%) completed the survey. Previous participation in clinical trials was reported by 112 patients (28%). Most were unaware of online information about clinical trials (330 [82%]), were satisfied with their current knowledge (233 [58%]), expected their treating physician to inform them about current trials (304 [76%]), and showed equal interest in participating in conventional or complementary intervention trials (174 [44%]). Of the 400 respondents, 321 (80%) found it appropriate to be contacted by mail and 253 (63%) by telephone regarding study participation. Most patients (364 [91%]) wanted to be informed about research findings or else would not participate in future clinical trials (272 [68%]). The most frequently expected compensation was free parking (234 [58%]). Most thought that their safety (373 [93%]) and privacy (376 [94%]) would be guarded. CONCLUSION: Patients are interested in participating in clinical trials but commonly lack adequate information. If patients received more information (through their treating physicians), enrollment might improve. This single-site study has limited generalizability. Future studies involving a diverse group of patients from a broader geographic distribution will help provide more definitive results. PMID:19252111

  4. The Harmonising Outcome Measures for Eczema (HOME) statement to assess clinical signs of atopic eczema in trials.

    PubMed

    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.

  5. Information giving in clinical trials: the views of medical researchers.

    PubMed

    Ferguson, P R

    2003-02-01

    It is both an ethical and legal requirement that patients who participate in clinical trials must generally give their consent. As part of this process, patients must be provided with adequate information to enable them to decide whether or not to take part. In the UK, the pharmaceutical companies that sponsor such research, as well as Local Research Ethics Committees, specify in detail the information that must be given to trial participants. The researchers who conduct clinical trials inevitably form views on the amount of information they are required to provide, and about patients' comprehension of that information. The literature in this area suggests that some medical researchers may be unhappy with the amount of information that they must give patient participants. There have been, however, few systematic attempts to determine their views. This paper reports a study that explored researchers' views as to (i) the amount of information provided to trial participants, and (ii) participants' understanding of that information. Researchers generally felt that they were required to give trial participants an appropriate amount of information, and that most patients had at least a reasonable understanding of key aspects of the clinical trials' process. However, there were differing views as to the level of information that they felt patients themselves wanted. The researchers did not generally feel that the patients' inability to comprehend information rendered the process of obtaining 'informed consent' a waste of time. However, some did believe that they were required to burden patients with excessive information.

  6. Interim analyses in 2 x 2 crossover trials.

    PubMed

    Cook, R J

    1995-09-01

    A method is presented for performing interim analyses in long term 2 x 2 crossover trials with serial patient entry. The analyses are based on a linear statistic that combines data from individuals observed for one treatment period with data from individuals observed for both periods. The coefficients in this linear combination can be chosen quite arbitrarily, but we focus on variance-based weights to maximize power for tests regarding direct treatment effects. The type I error rate of this procedure is controlled by utilizing the joint distribution of the linear statistics over analysis stages. Methods for performing power and sample size calculations are indicated. A two-stage sequential design involving simultaneous patient entry and a single between-period interim analysis is considered in detail. The power and average number of measurements required for this design are compared to those of the usual crossover trial. The results indicate that, while there is minimal loss in power relative to the usual crossover design in the absence of differential carry-over effects, the proposed design can have substantially greater power when differential carry-over effects are present. The two-stage crossover design can also lead to more economical studies in terms of the expected number of measurements required, due to the potential for early stopping. Attention is directed toward normally distributed responses.

  7. Improving the analysis of composite endpoints in rare disease trials.

    PubMed

    McMenamin, Martina; Berglind, Anna; Wason, James M S

    2018-05-22

    Composite endpoints are recommended in rare diseases to increase power and/or to sufficiently capture complexity. Often, they are in the form of responder indices which contain a mixture of continuous and binary components. Analyses of these outcomes typically treat them as binary, thus only using the dichotomisations of continuous components. The augmented binary method offers a more efficient alternative and is therefore especially useful for rare diseases. Previous work has indicated the method may have poorer statistical properties when the sample size is small. Here we investigate small sample properties and implement small sample corrections. We re-sample from a previous trial with sample sizes varying from 30 to 80. We apply the standard binary and augmented binary methods and determine the power, type I error rate, coverage and average confidence interval width for each of the estimators. We implement Firth's adjustment for the binary component models and a small sample variance correction for the generalized estimating equations, applying the small sample adjusted methods to each sub-sample as before for comparison. For the log-odds treatment effect the power of the augmented binary method is 20-55% compared to 12-20% for the standard binary method. Both methods have approximately nominal type I error rates. The difference in response probabilities exhibit similar power but both unadjusted methods demonstrate type I error rates of 6-8%. The small sample corrected methods have approximately nominal type I error rates. On both scales, the reduction in average confidence interval width when using the adjusted augmented binary method is 17-18%. This is equivalent to requiring a 32% smaller sample size to achieve the same statistical power. The augmented binary method with small sample corrections provides a substantial improvement for rare disease trials using composite endpoints. We recommend the use of the method for the primary analysis in relevant rare

  8. Methods for synthesizing findings on moderation effects across multiple randomized trials.

    PubMed

    Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

    2013-04-01

    This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design.

  9. A cluster randomised feasibility trial evaluating six-month nutritional interventions in the treatment of malnutrition in care home-dwelling adults: recruitment, data collection and protocol.

    PubMed

    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

  10. Acupuncture for alcohol withdrawal: a randomized controlled trial.

    PubMed

    Trümpler, François; Oez, Suzan; Stähli, Peter; Brenner, Hans Dieter; Jüni, Peter

    2003-01-01

    Previous trials on acupuncture in alcohol addiction were in outpatients and focused on relapse prevention. Rates of dropout were high and interpretation of results difficult. We compared auricular laser and needle acupuncture with sham laser stimulation in reducing the duration of alcohol withdrawal. Inpatients undergoing alcohol withdrawal were randomly allocated to laser acupuncture (n = 17), needle acupuncture (n = 15) or sham laser stimulation (n = 16). Attempts were made to blind patients, therapists and outcome assessors, but this was not feasible for needle acupuncture. The duration of withdrawal symptoms (as assessed using a nurse-rated scale) was the primary outcome; the duration of sedative prescription was the secondary outcome. Patients randomized to laser and sham laser had identical withdrawal symptom durations (median 4 days). Patients randomized to needle stimulation had a shorter duration of withdrawal symptoms (median 3 days; P = 0.019 versus sham intervention), and tended to have a shorter duration of sedative use, but these differences diminished after adjustment for baseline differences. The data from this pilot trial do not suggest a relevant benefit of auricular laser acupuncture for alcohol withdrawal. A larger trial including adequate sham interventions is needed, however, to reliably determine the effectiveness of any type of auricular acupuncture in this condition.

  11. Effectiveness guidance document (EGD) for Chinese medicine trials: a consensus document

    PubMed Central

    2014-01-01

    Background There is a need for more Comparative Effectiveness Research (CER) on Chinese medicine (CM) to inform clinical and policy decision-making. This document aims to provide consensus advice for the design of CER trials on CM for researchers. It broadly aims to ensure more adequate design and optimal use of resources in generating evidence for CM to inform stakeholder decision-making. Methods The Effectiveness Guidance Document (EGD) development was based on multiple consensus procedures (survey, written Delphi rounds, interactive consensus workshop, international expert review). To balance aspects of internal and external validity, multiple stakeholders, including patients, clinicians, researchers and payers were involved in creating this document. Results Recommendations were developed for “using available data” and “future clinical studies”. The recommendations for future trials focus on randomized trials and cover the following areas: designing CER studies, treatments, expertise and setting, outcomes, study design and statistical analyses, economic evaluation, and publication. Conclusion The present EGD provides the first systematic methodological guidance for future CER trials on CM and can be applied to single or multi-component treatments. While CONSORT statements provide guidelines for reporting studies, EGDs provide recommendations for the design of future studies and can contribute to a more strategic use of limited research resources, as well as greater consistency in trial design. PMID:24885146

  12. Solar- and wind-powered irrigation systems

    NASA Astrophysics Data System (ADS)

    Enochian, R. V.

    1982-02-01

    Five different direct solar and wind energy systems are technically feasible for powering irrigation pumps. However, with projected rates of fossil fuel costs, only two may produce significant unsubsidied energy for irrigation pumping before the turn of the century. These are photovoltaic systems with nonconcentrating collectors (providing that projected costs of manufacturing solar cells prove correct); and wind systems, especially in remote areas where adequate wind is available.

  13. A Powered Prosthetic Intervention for Bilateral Transfemoral Amputees

    PubMed Central

    Lawson, Brian E.; Ruhe, Brian; Shultz, Amanda; Goldfarb, Michael

    2014-01-01

    This paper presents the design and validation of a control system for a pair of powered knee and ankle prostheses to be used as a prosthetic intervention for bilateral transfemoral amputees. The control system leverages communication between the prostheses for enhanced awareness and stability, along with power generation at the knee and ankle joints to better restore biomechanical functionality in level ground walking. The control methodology employed is a combination of an impedance-based framework for weight-bearing portions of gait and a trajectory-based approach for the non-weight-bearing portions. The control system was implemented on a pair of self-contained powered knee and ankle prostheses, and the ability of the prostheses and control approach to provide walking functionality was assessed in a set of experimental trials with a bilateral transfemoral amputee subject. Specifically, experimental data from these trials indicate that the powered prostheses and bilateral control architecture provide gait kinematics that reproduce healthy gait kinematics to a greater extent than the subject’s daily-use passive prostheses. PMID:25014950

  14. Simulation-based power calculations for planning a two-stage individual participant data meta-analysis.

    PubMed

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

    2018-05-18

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

  15. Time Trials Versus Time-to-Exhaustion Tests: Effects on Critical Power, W', and Oxygen-Uptake Kinetics.

    PubMed

    Karsten, Bettina; Baker, Jonathan; Naclerio, Fernando; Klose, Andreas; Bianco, Antonino; Nimmerichter, Alfred

    2018-02-01

    To investigate single-day time-to-exhaustion (TTE) and time-trial (TT) -based laboratory tests values of critical power (CP), W prime (W'), and respective oxygen-uptake-kinetic responses. Twelve cyclists performed a maximal ramp test followed by 3 TTE and 3 TT efforts interspersed by 60 min recovery between efforts. Oxygen uptake ( V ˙ O 2 ) was measured during all trials. The mean response time was calculated as a description of the overall [Formula: see text]-kinetic response from the onset to 2 min of exercise. TTE-determined CP was 279 ± 52 W, and TT-determined CP was 276 ± 50 W (P = .237). Values of W' were 14.3 ± 3.4 kJ (TTE W') and 16.5 ± 4.2 kJ (TT W') (P = .028). While a high level of agreement (-12 to 17 W) and a low prediction error of 2.7% were established for CP, for W' limits of agreements were markedly lower (-8 to 3.7 kJ), with a prediction error of 18.8%. The mean standard error for TTE CP values was significantly higher than that for TT CP values (2.4% ± 1.9% vs 1.2% ± 0.7% W). The standard errors for TTE W' and TT W' were 11.2% ± 8.1% and 5.6% ± 3.6%, respectively. The [Formula: see text] response was significantly faster during TT (~22 s) than TTE (~28 s). The TT protocol with a 60-min recovery period offers a valid, time-saving, and less error-filled alternative to conventional and more recent testing methods. Results, however, cannot be transferred to W'.

  16. Exercise Training in Treatment and Rehabilitation of Hip Osteoarthritis: A 12-Week Pilot Trial

    PubMed Central

    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

  17. Planning Beyond the Next Trial in Adaptive Experiments: A Dynamic Programming Approach.

    PubMed

    Kim, Woojae; Pitt, Mark A; Lu, Zhong-Lin; Myung, Jay I

    2017-11-01

    Experimentation is at the heart of scientific inquiry. In the behavioral and neural sciences, where only a limited number of observations can often be made, it is ideal to design an experiment that leads to the rapid accumulation of information about the phenomenon under study. Adaptive experimentation has the potential to accelerate scientific progress by maximizing inferential gain in such research settings. To date, most adaptive experiments have relied on myopic, one-step-ahead strategies in which the stimulus on each trial is selected to maximize inference on the next trial only. A lingering question in the field has been how much additional benefit would be gained by optimizing beyond the next trial. A range of technical challenges has prevented this important question from being addressed adequately. This study applies dynamic programming (DP), a technique applicable for such full-horizon, "global" optimization, to model-based perceptual threshold estimation, a domain that has been a major beneficiary of adaptive methods. The results provide insight into conditions that will benefit from optimizing beyond the next trial. Implications for the use of adaptive methods in cognitive science are discussed. Copyright © 2016 Cognitive Science Society, Inc.

  18. Nuclear Power - Post Fukushima

    NASA Astrophysics Data System (ADS)

    Reyes, Jose, Jr.

    2011-10-01

    The extreme events that led to the prolonged power outage at the Fukushima Daiicchi nuclear plant have highlighted the importance of assuring a means for stable long term cooling of the nuclear fuel and containment following a complete station blackout. Legislative bodies, regulatory agencies and industry are drawing lessons from those events and considering what changes, if any, are needed to nuclear power, post Fukushima. The enhanced safety of a new class of reactor designed by NuScale Power is drawing significant attention in light of the Fukushima events. During normal operation, each NuScale containment is fully immersed in a water-filled stainless steel lined concrete pool that resides underground. The pool, housed in a Seismic Category I building, is large enough to provided 30 days of core and containment cooling without adding water. After 30 days, the decay heat generations coupled with thermal radiation heat transfer is completely adequate to remove core decay heat for an unlimited period of time. These passive power systems can perform their function without requiring an external supply of water of power. An assessment of the NuScale passive systems is being performed through a comprehensive test program that includes the NuScale integral system test facility at Oregon State University

  19. The Virtual Anemia Trial: An Assessment of Model‐Based In Silico Clinical Trials of Anemia Treatment Algorithms in Patients With Hemodialysis

    PubMed Central

    Topping, Alice; Kappel, Franz; Thijssen, Stephan; Kotanko, Peter

    2018-01-01

    In silico approaches have been proposed as a novel strategy to increase the repertoire of clinical trial designs. Realistic simulations of clinical trials can provide valuable information regarding safety and limitations of treatment protocols and have been shown to assist in the cost‐effective planning of clinical studies. In this report, we present a blueprint for the stepwise integration of internal, external, and ecological validity considerations in virtual clinical trials (VCTs). We exemplify this approach in the context of a model‐based in silico clinical trial aimed at anemia treatment in patients undergoing hemodialysis (HD). Hemoglobin levels and subsequent anemia treatment were simulated on a per patient level over the course of a year and compared to real‐life clinical data of 79,426 patients undergoing HD. The novel strategies presented here, aimed to improve external and ecological validity of a VCT, significantly increased the predictive power of the discussed in silico trial. PMID:29368434

  20. Implementation of selective prevention for cardiometabolic diseases; are Dutch general practices adequately prepared?

    PubMed

    Stol, Daphne M; Hollander, Monika; Nielen, Markus M J; Badenbroek, Ilse F; Schellevis, François G; de Wit, Niek J

    2018-03-01

    Current guidelines acknowledge the need for cardiometabolic disease (CMD) prevention and recommend five-yearly screening of a targeted population. In recent years programs for selective CMD-prevention have been developed, but implementation is challenging. The question arises if general practices are adequately prepared. Therefore, the aim of this study is to assess the organizational preparedness of Dutch general practices and the facilitators and barriers for performing CMD-prevention in practices currently implementing selective CMD-prevention. Observational study. Dutch primary care. General practices. Organizational characteristics. General practices implementing selective CMD-prevention are more often organized as a group practice (49% vs. 19%, p = .000) and are better organized regarding chronic disease management compared to reference practices. They are motivated for performing CMD-prevention and can be considered as 'frontrunners' of Dutch general practices with respect to their practice organization. The most important reported barriers are a limited availability of staff (59%) and inadequate funding (41%). The organizational infrastructure of Dutch general practices is considered adequate for performing most steps of selective CMD-prevention. Implementation of prevention programs including easily accessible lifestyle interventions needs attention. All stakeholders involved share the responsibility to realize structural funding for programmed CMD-prevention. Aforementioned conditions should be taken into account with respect to future implementation of selective CMD-prevention. Key Points   There is need for adequate CMD prevention. Little is known about the organization of selective CMD prevention in general practices.   • The organizational infrastructure of Dutch general practices is adequate for performing most steps of selective CMD prevention.   • Implementation of selective CMD prevention programs including easily accessible

  1. Socio-economic benefits of electric power

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

    Clemente, F.

    1979-01-01

    Empirical evidence and actual experience strongly demonstrate that the socio-economic benefits of electric power have received less than adequate attention. In terms of the reliability issue, so much emphasis has been placed on the cost of having electricity that the cost of not having reliable power has been ignored. Apart from a few comments on jobs or taxes, the Environmental Impact Statements submitted by utilities generally ignore the broad range of socio-economic (quality of life) benefits the proposed facility will have for the local community, the region, and society at large. The author feels strongly that electric utilities should notmore » look askance at the soft sciences, but should begin to utilize them. Sociology, social welfare, and macroeconomics remain fertile ground for the electric-power industry. The techniques and concepts of the social sciences can be readily utilized to identify and document many heretofore unarticulated socio-economic benefits of electric power.« less

  2. The content of African diets is adequate to achieve optimal efficacy with fixed-dose artemether-lumefantrine: a review of the evidence

    PubMed Central

    Premji, Zulfiqarali G; Abdulla, Salim; Ogutu, Bernhards; Ndong, Alice; Falade, Catherine O; Sagara, Issaka; Mulure, Nathan; Nwaiwu, Obiyo; Kokwaro, Gilbert

    2008-01-01

    A fixed-dose combination of artemether-lumefantrine (AL, Coartem®) has shown high efficacy, good tolerability and cost-effectiveness in adults and children with uncomplicated malaria caused by Plasmodium falciparum. Lumefantrine bioavailability is enhanced by food, particularly fat. As the fat content of sub-Saharan African meals is approximately a third that of Western countries, it raises the question of whether fat consumption by African patients is sufficient for good efficacy. Data from healthy volunteers have indicated that drinking 36 mL soya milk (containing only 1.2 g of fat) results in 90% of the lumefantrine absorption obtained with 500 mL milk (16 g fat). African diets are typically based on a carbohydrate staple (starchy root vegetables, fruit [plantain] or cereals) supplemented by soups, relishes and sauces derived from vegetables, pulses, nuts or fish. The most important sources of dietary fat in African countries are oil crops (e.g. peanuts, soya beans) and cooking oils as red palm, peanut, coconut and sesame oils. Total fat intake in the majority of subSaharan countries is estimated to be in the range 30–60 g/person/day across the whole population (average 43 g/person/day). Breast-feeding of infants up to two years of age is standard, with one study estimating a fat intake of 15–30 g fat/day from breast milk up to the age of 18 months. Weaning foods typically contain low levels of fat, and the transition from breast milk to complete weaning is associated with a marked reduction in dietary fat. Nevertheless, fat intake >10 g/day has been reported in young children post-weaning. A randomized trial in Uganda reported no difference in the efficacy of AL between patients receiving supervised meals with a fixed fat content (~23 g fat) or taking AL unsupervised, suggesting that fat intake at home was sufficient for optimal efficacy. Moreover, randomized trials in African children aged 5–59 months have shown similar high cure rates to those observed

  3. Economic burden of clinical trials in lung cancer in a German Comprehensive Cancer Center.

    PubMed

    Kron, F; Kostenko, A; Scheffler, M; Müller, D; Glossmann, J-P; Fischer, R; Michels, S; Nogova, L; Hallek, M; Zander, T; Wolf, J

    2017-06-01

    The recent success of individualized lung cancer therapy has triggered fundamental changes in clinical research strategies. To date there is a strong focus on early proof of concept trials in genetically preselected small patient subgroups. This analysis focuses on the economic burden caused by such trials for advanced lung cancer patients in a German Comprehensive Cancer Center (CCC). The profit margins between recruiting groups with ≤3 and >3 patients were compared. Clinical and economic data from clinical trials for advanced lung cancer (LC), pharma-sponsored trials (PhST) as well as investigator initiated trials (IIT), conducted between 2011 and 2015 at the Center for Integrated Oncology (CIO) Cologne, were analyzed using a profit-center calculation model. 161 patients were enrolled in 27 clinical trials. The key economic parameter determining costs and payments was the 'trial visits'. In comparison of the two groups (A≤3; B>3 patients enrolled) we found negative profit margins for the low recruiting group (€ -1444). Concerning the number of visits significant differences were found between PhST and IIT (p=0.009). Additionally, sub-analysis show structural differences in cost composition by conducting PhST and IIT. Trials with low patient numbers and IIT, do not cover the cost. To ensure adequate, cost-covering compensation by pharmaceutical companies CCCs have to thoroughly calculate the cost of early proof of concept trials. The findings of this study also underline the need for novel structures in public funding for investigator-initiated clinical trials in precision medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Statistical Frequency-Dependent Analysis of Trial-to-Trial Variability in Single Time Series by Recurrence Plots.

    PubMed

    Tošić, Tamara; Sellers, Kristin K; Fröhlich, Flavio; Fedotenkova, Mariia; Beim Graben, Peter; Hutt, Axel

    2015-01-01

    For decades, research in neuroscience has supported the hypothesis that brain dynamics exhibits recurrent metastable states connected by transients, which together encode fundamental neural information processing. To understand the system's dynamics it is important to detect such recurrence domains, but it is challenging to extract them from experimental neuroscience datasets due to the large trial-to-trial variability. The proposed methodology extracts recurrent metastable states in univariate time series by transforming datasets into their time-frequency representations and computing recurrence plots based on instantaneous spectral power values in various frequency bands. Additionally, a new statistical inference analysis compares different trial recurrence plots with corresponding surrogates to obtain statistically significant recurrent structures. This combination of methods is validated by applying it to two artificial datasets. In a final study of visually-evoked Local Field Potentials in partially anesthetized ferrets, the methodology is able to reveal recurrence structures of neural responses with trial-to-trial variability. Focusing on different frequency bands, the δ-band activity is much less recurrent than α-band activity. Moreover, α-activity is susceptible to pre-stimuli, while δ-activity is much less sensitive to pre-stimuli. This difference in recurrence structures in different frequency bands indicates diverse underlying information processing steps in the brain.

  5. Statistical Frequency-Dependent Analysis of Trial-to-Trial Variability in Single Time Series by Recurrence Plots

    PubMed Central

    Tošić, Tamara; Sellers, Kristin K.; Fröhlich, Flavio; Fedotenkova, Mariia; beim Graben, Peter; Hutt, Axel

    2016-01-01

    For decades, research in neuroscience has supported the hypothesis that brain dynamics exhibits recurrent metastable states connected by transients, which together encode fundamental neural information processing. To understand the system's dynamics it is important to detect such recurrence domains, but it is challenging to extract them from experimental neuroscience datasets due to the large trial-to-trial variability. The proposed methodology extracts recurrent metastable states in univariate time series by transforming datasets into their time-frequency representations and computing recurrence plots based on instantaneous spectral power values in various frequency bands. Additionally, a new statistical inference analysis compares different trial recurrence plots with corresponding surrogates to obtain statistically significant recurrent structures. This combination of methods is validated by applying it to two artificial datasets. In a final study of visually-evoked Local Field Potentials in partially anesthetized ferrets, the methodology is able to reveal recurrence structures of neural responses with trial-to-trial variability. Focusing on different frequency bands, the δ-band activity is much less recurrent than α-band activity. Moreover, α-activity is susceptible to pre-stimuli, while δ-activity is much less sensitive to pre-stimuli. This difference in recurrence structures in different frequency bands indicates diverse underlying information processing steps in the brain. PMID:26834580

  6. Ethical implications of excessive cluster sizes in cluster randomised trials.

    PubMed

    Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

    2018-02-20

    The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

  7. Immuno-oncology Clinical Trial Design: Limitations, Challenges, and Opportunities

    PubMed Central

    Baik, Christina S.; Rubin, Eric H.; Forde, Patrick M.; Mehnert, Janice M.; Collyar, Deborah; Butler, Marcus O.; Dixon, Erica L.; Chow, Laura Q.M.

    2017-01-01

    Recent advances in immuno-oncology and regulatory approvals have been rapid and paradigm shifting in many difficult-to-treat malignancies. Despite immune checkpoint inhibitor therapy becoming the standard of care across multiple tumor types, there are many unanswered questions that need to be addressed before this therapeutic modality can be fully harnessed. Areas of limitations include treatment of patients not sufficiently represented in clinical trials, uncertainty of the optimal treatment dosing and duration, and lack of understanding regarding long-term immune related toxicities and atypical tumor responses. Patients such as those with autoimmune disease, chronic viral infections, limited performance status, and brain metastases were often excluded from initial trials due to concerns of safety. However, limited data suggest that some of these patients can benefit from therapy with manageable toxicities; thus, future studies should incorporate these patients to clearly define safety and efficacy. There are still controversies regarding the optimal dosing strategy that can vary from weight-based to flat dosing, with undefined treatment duration. Further elucidation of the optimal dosing approach and evaluation of predictive biomarkers should be incorporated in the design of future trials. Finally, there are long-term immune-mediated toxicities, atypical tumor responses such as pseudoprogression and endpoints unique to immuno-oncology that are not adequately captured by traditional trial designs; thus, novel study designs are needed. In this article, we discuss in detail the above challenges and propose needed areas of research for exploration and incorporation in the next generation of immuno-oncology clinical trials. PMID:28864727

  8. A randomised controlled trial of a probiotic 'functional food' in the management of irritable bowel syndrome.

    PubMed

    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.

  9. Behavioral interventions to promote adequate sleep among women: protocol for a systematic review and meta-analysis.

    PubMed

    Vézina-Im, Lydi-Anne; Moreno, Jennette Palcic; Nicklas, Theresa A; Baranowski, Tom

    2017-05-11

    Short and poor sleep have been associated with adverse health outcomes in adults, such as overweight/obesity and type 2 diabetes, especially among women. Women therefore represent an important target for interventions aimed at improving sleep and such interventions have been advocated to enhance maternal, fetal, and infant health. This systematic review will assess the efficacy or effectiveness of behavioral interventions aimed at promoting adequate sleep among women. The primary outcomes will be changes in sleep duration and/or sleep quality from baseline to post-intervention and to the last available follow-up measured either through self-reports or objectively. Secondary outcomes will be assessing the behavior change techniques that are responsible for the changes in sleep duration and quality among women. Behavioral interventions that are non-pharmacological and target either sleep directly or sleep hygiene behaviors will be included. Randomized controlled trials, quasi-experimental, and one-group pre-post studies will be included, but treated separately in the analyses, given that a limited number of studies on the topic of sleep is expected. MEDLINE/PubMed, PsycINFO, CINAHL, EMBASE, and Proquest Dissertations and Theses will be investigated. There will be no restriction on the year of publication of the articles, but we will include only the ones written in English or French. Two authors will independently assess articles for eligibility and will extract data using a standardized data extraction form that will have been previously pilot-tested. The quality of the studies will be assessed using the Effective Public Health Practice Project tool for quantitative study designs. The intervention procedures will be classified according to the latest validated taxonomy of behavior change techniques. If there is a sufficient number of studies (k > 5), a meta-analysis of the results will be performed with a random-effect model. If the heterogeneity is high (I 2

  10. Smart Technology in Lung Disease Clinical Trials.

    PubMed

    Geller, Nancy L; Kim, Dong-Yun; Tian, Xin

    2016-01-01

    This article describes the use of smart technology by investigators and patients to facilitate lung disease clinical trials and make them less costly and more efficient. By "smart technology" we include various electronic media, such as computer databases, the Internet, and mobile devices. We first describe the use of electronic health records for identifying potential subjects and then discuss electronic informed consent. We give several examples of using the Internet and mobile technology in clinical trials. Interventions have been delivered via the World Wide Web or via mobile devices, and both have been used to collect outcome data. We discuss examples of new electronic devices that recently have been introduced to collect health data. While use of smart technology in clinical trials is an exciting development, comparison with similar interventions applied in a conventional manner is still in its infancy. We discuss advantages and disadvantages of using this omnipresent, powerful tool in clinical trials, as well as directions for future research. Published by Elsevier Inc.

  11. Diagnostic games: from adequate formalization of clinical experience to structure discovery.

    PubMed

    Shifrin, Michael A; Kasparova, Eva I

    2008-01-01

    A method of obtaining well-founded and reproducible results in clinical decision making is presented. It is based on "diagnostic games", a procedure of elicitation and formalization of experts' knowledge and experience. The use of this procedure allows formulating decision rules in the terms of an adequate language, that are both unambiguous and clinically clear.

  12. Moderate quality evidence finds statistical benefit in oral health for powered over manual toothbrushes.

    PubMed

    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

  13. Randomised controlled trial and economic analysis of an internet-based weight management programme: POWeR+ (Positive Online Weight Reduction).

    PubMed Central

    Little, Paul; Stuart, Beth; Hobbs, Fd Richard; Kelly, Jo; Smith, Emily R; Bradbury, Katherine J; Hughes, Stephanie; Smith, Peter Wf; Moore, Michael V; Lean, Mike Ej; Margetts, Barrie M; Byrne, Christopher D; Griffin, Simon; Davoudianfar, Mina; Hooper, Julie; Yao, Guiqing; Zhu, Shihua; Raftery, James; Yardley, Lucy

    2017-01-01

    BACKGROUND Behavioural counselling with intensive follow-up for obesity is effective, but in resource-constrained primary care settings briefer approaches are needed. OBJECTIVES To estimate the clinical effectiveness and cost-effectiveness of an internet-based behavioural intervention with regular face-to-face or remote support in primary care, compared with brief advice. DESIGN Individually randomised three-arm parallel trial with health economic evaluation and nested qualitative interviews. SETTING Primary care general practices in the UK. PARTICIPANTS Patients with a body mass index of ≥ 30 kg/m(2) (or ≥ 28 kg/m(2) with risk factors) identified from general practice records, recruited by postal invitation. INTERVENTIONS Positive Online Weight Reduction (POWeR+) is a 24-session, web-based weight management intervention completed over 6 months. Following online registration, the website randomly allocated participants using computer-generated random numbers to (1) the control intervention (n = 279), which had previously been demonstrated to be clinically effective (brief web-based information that minimised pressure to cut down foods, instead encouraging swaps to healthier choices and increasing fruit and vegetables, plus 6-monthly nurse weighing); (2) POWeR+F (n = 269), POWeR+ supplemented by face-to-face nurse support (up to seven contacts); or (3) POWeR+R (n = 270), POWeR+ supplemented by remote nurse support (up to five e-mails or brief telephone calls). MAIN OUTCOME MEASURES The primary outcome was a modelled estimate of average weight reduction over 12 months, assessed blind to group where possible, using multiple imputation for missing data. The secondary outcome was the number of participants maintaining a 5% weight reduction at 12 months. RESULTS A total of 818 eligible individuals were randomised using computer-generated random numbers. Weight change, averaged over 12 months, was documented in 666 out of 818 participants (81

  14. Human milk feeding supports adequate growth in infants

    USDA-ARS?s Scientific Manuscript database

    Despite current nutritional strategies, premature infants remain at high risk for extrauterine growth restriction. The use of an exclusive human milk-based diet is associated with decreased incidence of necrotizing enterocolitis (NEC), but concerns exist about infants achieving adequate growth. The ...

  15. Physicians' perspective on the clinical meaningfulness of inflammatory bowel disease trial results: an International Organization for the Study of Inflammatory Bowel Disease (IOIBD) survey.

    PubMed

    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.

  16. 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…

  17. Stent thrombosis: insights on outcomes, predictors and impact of dual antiplatelet therapy interruption from the SPIRIT II, SPIRIT III, SPIRIT IV and COMPARE trials.

    PubMed

    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.

  18. [Prevention and handling of missing data in clinical trials].

    PubMed

    Jiang, Zhi-wei; Li, Chan-juan; Wang, Ling; Xia, Jie-lai

    2015-11-01

    Missing data is a common but unavoidable issue in clinical trials. It not only lowers the trial power, but brings the bias to the trial results. Therefore, on one hand, the missing data handling methods are employed in data analysis. On the other hand, it is vital to prevent the missing data in the trials. Prevention of missing data should take the first place. From the perspective of data, firstly, some measures should be taken at the stages of protocol design, data collection and data check to enhance the patients' compliance and reduce the unnecessary missing data. Secondly, the causes of confirmed missing data in the trials should be notified and recorded in detail, which are very important to determine the mechanism of missing data and choose the suitable missing data handling methods, e.g., last observation carried forward (LOCF); multiple imputation (MI); mixed-effect model repeated measure (MMRM), etc.

  19. Lee Silverman Voice Treatment versus standard speech and language therapy versus control in Parkinson's disease: a pilot randomised controlled trial (PD COMM pilot).

    PubMed

    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.

  20. Characteristics associated with suppression of spermatogenesis in a male hormonal contraceptive trial using testosterone and Nestorone(®) gels.

    PubMed

    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.