Clinical trials : journal of the Society for Clinical Trials
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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.
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Sample size decisions for clinical trials should be taken in such a way as to maximize informed choice by reducing scientific uncertainty about the consequences of an intervention. ⋯ The approach is a pragmatic aid to trial design in settings where patient preference drives the choice between alternative treatments.
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Traditionally, phase I clinical trial designs are based upon one predefined course of treatment while varying among patients the dose given at each administration. In actual medical practice, patients receive a schedule comprised of several courses of treatment, and some patients may receive one or more dose reductions or delays during treatment. Consequently, the overall risk of toxicity for each patient is a function of both actual schedule of treatment and the differing doses used at each adminstration. ⋯ Our design is the first for phase I clinical trials that is sufficiently flexible and practical to truly reflect clinical practice by varying both dose and the timing and number of administrations given to each patient.
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Disclosing financial interests to potential research participants during the informed consent process is one strategy for managing conflicts of interest. Given that clinical research coordinators are typically charged with administering the informed consent process, it is critical to understand their experiences, attitudes and beliefs regarding the disclosure of financial interests in research. ⋯ Making information about financial interests in research readily available to clinical research coordinators, as well as providing education and training, should facilitate the disclosure of financial interests in research to potential research participants during the informed consent process.