Cluster randomized controlled trials

Cluster randomized controlled trial (RCT), in which groups or clusters of individuals rather than individuals themselves are randomized, are increasingly common. Indeed, for the evaluation of certain types of intervention (such as those used in health promotion and educational interventions) a cluster randomized trial is virtually the only valid approach. However, cluster trials are generally more difficult to design and execute than individually randomized studies, and some design features of a cluster trial may make it particularly vulnerable to a range of threats that can introduce bias. In this paper we discuss the issues that can lead to bias in cluster randomized trials and conclude with some suggestions for avoiding these problems.     

Update in intensive care medicine: studies that challenged our practice in the last 5 years

During the last 5 years, new randomized trials in critically ill patients have challenged a number of traditional treatment strategies in intensive care. The authors review eight studies that helped change their medical practices.     

ICU Cornestone: a lecture that changed my practice

In 1982, the author attended a lecture by Professor Joseph Civetta dealing with the concept that, at times, the goal of care should be comfort rather than cure, and that inappropriate care prolonged dying and suffering. Efforts to improve end-of-life care subsequent to this had effects on care at a local level and at a state level. Intensive care providers should be leaders in the provision of appropriate and compassionate care at the end of life.     

Adaptive allocation in randomized controlled trials

Adaptive allocation has been proposed as a procedure to reduce the risk of chance imbalance of important prognostic factors in randomized controlled trials when the number of prognostic factors is large. In this article, minimization, a type of adaptive allocation, is compared to simple randomization and stratified allocation in a series of Monte Carlo simulations. Three outcomes are studied: estimated treatment effect, size of the rejection region, and power. Minimization produced an unbiased estimate of treatment effect and increased power when compared to simple randomization. Student's t test was conservative for both minimization and stratified allocation. Minimization and stratification produced similar improvements in power but there was some evidence that minimization might produce higher power than stratification when some prognostic variables cannot be included in the stratified allocation scheme.     

基于评判视角研读随机对照试验研究文献

目前护理随机对照试验（RCT）研究文献发表数量逐年上升,其研究结果对护士和护生的临床知识、护理行为以及开展科研均会产生潜在影响,采取评判的态度和系统的方法正确阐释RCT研究结果,是将研究结果转化为临床实践的关键一步。因此本文基于此理念,从以下3个方面来评价一项RCT研究的结果及临床意义：1可信度：学会判断RCT研究结果的信度和效度;2结果的阐释：学会从样本量和精度看临床统计结果 ;3适用性：学会研读外在效度和干预措施的副作用,判断新方法的适用对象。从而促进研究成果的临床转化,提升我国护理质量。     

Beyond randomized, controlled trials

PURPOSE OF REVIEW: Most critical care physicians believe that randomized, controlled trials provide the best available evidence. This review contends that the importance of randomized, controlled trials was overemphasized and that they do not add more to knowledge and practice than physiologic and observational studies. In addition, protection of both patients and proxies may be less adequately ensured during randomized, controlled trials than during observational studies. RECENT FINDINGS: An analysis of the recent literature on critical care shows that conclusions from randomized, controlled trials are either disputable or do not affect existing practice. In addition, several papers reveal potential conflicts between randomized, controlled trials and ethical principles. SUMMARY: We may see in the future the twilight of randomized, controlled trials in critically ill patients because scientific, ethical, and sociologic substrata will be progressively lacking as will be funding.     

Low-glycemic index diets in the management of diabetes: a meta-analysis of randomized controlled trials

OBJECTIVE: The use of diets with low glycemic index (GI) in the management of diabetes is controversial, with contrasting recommendations around the world. We performed a meta-analysis of randomized controlled trials to determine whether low-GI diets, compared with conventional or high-GI diets, improved overall glycemic control in individuals with diabetes, as assessed by reduced HbA(1c) or fructosamine levels. RESEARCH DESIGN AND METHODS: Literature searches identified 14 studies, comprising 356 subjects, that met strict inclusion criteria. All were randomized crossover or parallel experimental design of 12 days' to 12 months' duration (mean 10 weeks) with modification of at least two meals per day. Only 10 studies documented differences in postprandial glycemia on the two types of diet. RESULTS: Low-GI diets reduced HbA(1c) by 0.43% points (CI 0.72-0.13) over and above that produced by high-GI diets. Taking both HbA(1c) and fructosamine data together and adjusting for baseline differences, glycated proteins were reduced 7.4% (8.8-6.0) more on the low-GI diet than on the high-GI diet. This result was stable and changed little if the data were unadjusted for baseline levels or excluded studies of short duration. Systematically taking out each study from the meta-analysis did not change the CIs. CONCLUSIONS: Choosing low-GI foods in place of conventional or high-GI foods has a small but clinically useful effect on medium-term glycemic control in patients with diabetes. The incremental benefit is similar to that offered by pharmacological agents that also target postprandial hyperglycemia.     

Evolution of practice patterns in the management of acute respiratory distress syndrome: A secondary analysis of two successive randomized controlled trials

PurposeWe sought to examine changes in acute respiratory distress syndrome (ARDS) management over a 12-year period of two successive randomized trials.MethodsAnalyses included baseline data, from eligible patients, prior to influence of trial protocols, and daily study data, from randomized patients, of variables not determined by trial protocols. Mixed linear regressions examined changes in practice year-on-year.ResultsA total of 2376 patients met the inclusion criteria. Over the 12-year period, baseline tidal volume index decreased (9.0 to 7.0 ml/kg, p < 0.001), plateau pressures decreased (30.8 to 29.0 cmH₂O, p < 0.05), and baseline positive end-expiratory pressures increased (10.8 to 13.2 cmH₂O, p < 0.001). Volume-controlled ventilation declined from 29.4 to 14.0% (p < 0.01). Use of corticosteroids increased (baseline: 7.7 to 30.3%; on study: 32.6 to 61.2%; both p < 0.001), as did neuromuscular blockade (baseline: 12.3 to 24.5%; on study: 55.5 to 70.0%; both p < 0.01). Inhaled nitric oxide use increased (24.9 to 65.8%, p < 0.05). We observed no significant change in prone positioning (16.2 to 18.9%, p = 0.70).ConclusionsClear trends were apparent in tidal volume, airway pressures, ventilator modes, adjuncts and rescue therapies. With the exception of prone positioning, and outside the context of rescue therapy, these trends appear consistent with the evolving literature on ARDS management.     

The acute management of trauma hemorrhage: a systematic review of randomized controlled trials

Introduction  

Worldwide, trauma is a leading cause of death and disability. Haemorrhage is responsible for up to 40% of trauma deaths. Recent strategies to improve mortality rates have focused on optimal methods of early hemorrhage control and correction of coagulopathy. We undertook a systematic review of randomized controlled trials (RCT) which evaluated trauma patients with hemorrhagic shock within the first 24 hours of injury and appraised how the interventions affected three outcomes: bleeding and/or transfusion requirements; correction of trauma induced coagulopathy and mortality.     

Clinical effect of qigong practice on essential hypertension: a meta-analysis of randomized controlled trials

OBJECTIVES: This study was designed to quantitatively assess the effectiveness of self-practiced qigong for treatment of essential hypertension. METHODS: Six major electronic databases were searched up to July 2006 to retrieve any potential randomized controlled trials designed to evaluate the clinical effectiveness of self-practiced qigong for essential hypertension reported in any language, with main outcome measures as systolic blood pressure (SBP) and diastolic blood pressure (DBP). The quality of included studies were assessed with the Jadad Scale and a customized standard quality assessment scale. RESULTS: Ninety-two (92) studies were identified. Nine (9) of these studies qualified for meta-analysis, comprising a total of 908 cases. Results were as follows: (1) The mean decrease of SBP in those practicing qigong was a 17.03 mm Hg reduction (95% confidence interval (CI) 11.53-22.52) compared with nonspecific intervention controls, but not superior to that in drug controls (1.19 mm Hg, 95% CI -5.40-7.79) and conventional exercise controls (-1.51 mm Hg, 95% CI -6.98-3.95). (2) Mean decrease of DBP in those practicing qigong was 9.98 mm Hg (95% CI 2.55-17.41) compared with nonspecific intervention controls, but not superior to that in drug controls (2.49 mm Hg, 95% CI -0.16-5.13) and conventional exercise controls (-1.59 mm Hg, 95% CI -4.91-1.74). (3) No obvious side effects were identified. CONCLUSIONS: Self-practiced qigong for less than 1 year is better in decreasing BP in patients with essential hypertension than in no-treatment controls, but is not superior to that in active controls. More methodologically strict studies are needed to prove real clinical benefits of qigong, and to explore its potential mechanism.     

An analysis of randomized controlled trials underpinning ST-elevation myocardial infarction management guidelines

BackgroundThe fragility index (FI) is calculated by iteratively changing one outcome “event” to a “non-event” within a trial until the associated p-value exceeds 0.05.PurposeTo investigate the FI and fragility quotient (FQ) of trial endpoints referenced in the ACCF/AHA/SCAI guidelines in the management of ST-elevation myocardial infarctions. Secondarily, we assess the post-hoc power and risk of bias for these specific outcomes and whether differences exist between adequately and inadequately powered studies on fragility measures.Basic proceduresAll citations referenced in the guideline were screened for inclusion criteria. The FI and FQ for all included trials were then calculated. The Cochrane ‘risk of bias’ Tool 2.0 was used to evaluate the likelihood and sources of bias in the included trials.Main findingsForty-two randomized controlled trials were included for assessment. The median FI was 10 with a FQ of 0.0055. Seven trials were at a high risk of bias, all due to bias in the randomization process. Fifteen trials were found to be underpowered. Adequately powered studies had higher FIs and FQs compared to underpowered studies.Principal conclusionsOur findings support the use of FI and FQ analyses with power analyses in future methodology of randomized control trials. With understanding and reporting of FI and FQ, evidence of studies can be readily available and quickly eliminate some readers' concern for possible study limitations.     

Exercise parameters in the management of breast cancer: A systematic review of randomized controlled trials

Aim. Previous systematic reviews have examined the efficacy of exercise in improving the quality of life for patients with, and survivors of, breast cancer. This review sets out to determine the parameters of exercise programmes used in randomized controlled trials. Methods. A systematic review of randomized controlled trials was conducted. Only trials that reported significant improvement on the quality of life outcome were included. Data relating to the parameters of exercise (mode, duration, frequency and intensity and delivery method) were analyzed. Results. Nine randomized controlled trials were included in this review. Overall quality of the trials was average. Aerobic exercise was featured in eight of the nine trials and was used in combination with resistance training in four trials. All the trials were gym‐based, were under the supervision of a physiotherapist and included a warm‐up and cool‐down phase. Conclusions. This review concludes that aerobic exercise performed with or without weight training is a common feature of exercise programmes that report significant quality of life–related outcomes. The most commonly reported exercise parameters were three sessions per week, at moderate intensity being equivalent to 50% to 80% of the maximum heart rate for greater than 30 minutes. Copyright © 2010 John Wiley & Sons, Ltd.     

我国慢性胃炎治疗性研究的现状分析

目的：了解我国慢性胃炎治疗性研究的一般状况，特别是RCT／CCT的现状，以及能否为临床提供可靠的研究依据。方法：按中国循证医学中心及Cochrane手册标准对8种消化专业或与消化专业有关的临床中杂志逐篇人工查阅，登记所有慢性胃炎的临床治疗性研究，分析其中的RCT／CCT。结果：共查阅113卷823期，包括临床治疗性章214篇，并分析了RCT／CCT共81篇。结论：目前我国发表的慢性胃炎的防治性研究RCT／CCT的数量较少，质量差别大，还不能满足临床实践的需要，西药类药物防治性研究献RCT／CCT比例高于中医与中西医结合类药物。     

Dry needling in the management of myofascial trigger points: A systematic review of randomized controlled trials

ObjectiveThis systematic review of randomized controlled trials aimed to examine the effectiveness of dry needling in the treatment of myofascial trigger points and to explore the impact of specific aspects of the technique on its effectiveness.MethodsRelevant studies published between 2000 and 2015 were identified by searching PubMed, Scopus, The Cochrane Library and Physiotherapy Evidence Database. Studies identified by electronic searches were screened against a set of pre-defined inclusion criteria.ResultsFifteen studies were included in this systematic review. The main outcomes that were measured were pain, range of motion, disability, depression and quality of life. The results suggest that dry needling is effective in the short term for pain relief, increase range of motion and improve quality of life when compared to no intervention/sham/placebo. There is insufficient evidence on its effect on disability, analgesic medication intake and sleep quality.ConclusionsDespite some evidence for a positive effect in the short term, further randomized clinical trials of high methodological quality, using standardized procedures for the application of dry needling are needed.