Journal of clinical epidemiology
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The "Grades of Recommendation, Assessment, Development, and Evaluation" (GRADE) approach provides guidance for rating quality of evidence and grading strength of recommendations in health care. It has important implications for those summarizing evidence for systematic reviews, health technology assessment, and clinical practice guidelines. ⋯ Wide dissemination and use of the GRADE approach, with endorsement from more than 50 organizations worldwide, many highly influential (http://www.gradeworkinggroup.org/), attests to the importance of this work. This article introduces a 20-part series providing guidance for the use of GRADE methodology that will appear in the Journal of Clinical Epidemiology.
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The aim of this analysis was to explore the variation in measures of effect, such as the number-needed-to-treat (NNT) and the relative risk (RR). ⋯ For realistic values of true ARR, n, and p(0), the observed NNT varies much more than the observed ARR and RR. Clinicians should use NNT cautiously when expressing treatment benefits.
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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. ⋯ 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.
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To review methods for completing knowledge synthesis. ⋯ Given the magnitude of the literature, the increasing demands on knowledge syntheses teams, and the diversity of approaches, continuing efforts will be important to increase the efficiency, validity, and applicability of systematic reviews. Future research should focus on increasing the uptake of knowledge synthesis, how best to update reviews, the comparability between different types of reviews (eg, rapid vs. comprehensive reviews), and how to prioritize knowledge synthesis topics.