Clinical trials : journal of the Society for Clinical Trials
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Intention-to-treat (ITT) is an approach to the analysis of randomized controlled trials (RCT) in which patients are analyzed as randomized regardless of the treatment actually received. ⋯ This study emphasizes that authors use the label ;intention-to-treat' quite differently. The most common use refers to the analysis of all available subjects as randomized regardless of the missing data aspect.
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Innovative approaches are needed to allow for research in the emergency setting while not compromising either the rights or the interests of the subjects enrolled in such research. The emergency consent exception was developed to meet this need. ⋯ Careful attention should be paid by investigators and IRBs as to whether the emergency consent exception is really required for a particular study, or whether the study could proceed using only prospective consent with a longer recruitment period, more research sites, and a higher yield of available family members giving prospective consent. Measures that could shorten the time between initial contact and obtaining informed consent (for example, allowing consent over the phone rather than requiring written consent) might decrease the need for the emergency consent exception.
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Randomized Controlled Trial Multicenter Study
A study design to assess the safety and efficacy of on-pump versus off-pump coronary bypass grafting: the ROOBY trial.
Since the late 1960s, coronary artery bypass graft (CABG-only) procedures were traditionally performed using a heart-lung machine on an arrested heart (on-pump). Over the past decade, an increasing number CABG-only procedures were performed on a beating heart (off-pump). Advocates of the off-pump approach expect to reduce many of the adverse side effects related to using the heart-lung machine, while advocates for the on-pump procedure raise concerns related to graft patency rates and long-term event-free survival for the off-pump technique. ⋯ The study design presented allows for a balanced and fair assessment of the on-pump and off-pump CABG procedures across a diversity of clinical outcomes and resource use metrics. Its results have the potential to influence clinical cardiac surgical practice in the future.
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The decision to terminate a controlled clinical trial at the time of an interim analysis is perhaps best made by weighing the value of the likely additional information to be gained if further subjects are enrolled against the various costs of that further enrollment. The most commonly used statistical plans for interim analysis (eg, O'Brien-Fleming), however, are based on a frequentist approach that makes no such comparison. A two-armed Bayesian decision-theoretic clinical trial design is developed for a disease with two possible outcomes, incorporating a quadratic decision loss function and using backward induction to quantify the cost of future enrollment. ⋯ Our Bayesian designs allow interpretation of the final results along either Bayesian or frequentist lines. For the Bayesian, they minimize the total cost and allow the direct calculation of the probability density function for the difference in efficacy. For the frequentist, they have well-characterized type I and II error rates and in some cases lead to a reduction in the mean sample size.
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Randomized Controlled Trial
Quality assurance questionnaire for professionals fails to improve the quality of informed consent.
The informed consent process for research warrants improvement but approaches designed to enhance informed consent need testing in the context of actual clinical research. ⋯ Despite prior beliefs, a standardized quality assurance tool do not enhance informed consent in actual clinical trials. Future research is needed to rigorously evaluate proposed methods to enhance informed consent prior to widespread introduction.