Journal of clinical epidemiology
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PRagmatic Explanatory Continuum Indicator Summary (PRECIS)-2 is a tool that could improve design insight for trialists. Our aim was to validate the PRECIS-2 tool, unlike its predecessor, testing the discriminant validity and interrater reliability. ⋯ We have assessed the validity and reliability of PRECIS-2. An elaboration study and web site provide guidance to help future users of the tool which is continuing to be tested by trial teams, systematic reviewers, and funders.
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This second article in the series on pragmatic trials describes the challenges in selection of sites for pragmatic clinical trials and the impact on validity, precision, and generalizability of the results. The selection of sites is an important factor for the successful execution of a pragmatic trial and impacts the extent to which the results are applicable to future patients in clinical practice. ⋯ It can be advisable to support the sites with implementing the trial-related activities and minimize the additional burden that the research imposes on routine clinical practice. Health care providers should be involved in an early phase of protocol development to generate engagement and ensure an appropriate selection of sites with patients who are representative of the future drug users.
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This is the introductory paper in a series of eight papers. In this series, we integrate the theoretical design options with the practice of conducting pragmatic trials. For most new market-approved treatments, the clinical evidence is insufficient to fully guide physicians and policy makers in choosing the optimal treatment for their patients. ⋯ This paper introduces the concept of pragmatic trial design. The complex interplay between pragmatic design options, feasibility, stakeholder acceptability, validity, precision, and generalizability will be clarified. In this way, balanced design choices can be made in pragmatic trials with an optimal chance of success in practice.
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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. ⋯ 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.