Grading the Strength of a Body of Evidence When Comparing Medical Interventions. Methods Guide for Comparative Effectiveness Reviews

摘要

Comparative Effectiveness Reviews (CERs), like systematic reviews in general, are essential tools for summarizing information to help make well-informed decisions about health care options. CERs explicitly compare two or more screening or diagnostic strategies or therapeutic interventions. The Evidence-based Practice Center (EPC) program, supported by the U.S. Agency for Healthcare Research and Quality (AHRQ), produces substantial numbers of evidence reports and CERs. These reports are designed to accurately and transparently summarize a body of literature with the goal of helping clinicians, policymakers, and patients make well-informed decisions about health care. Reviews should provide clear judgments about the strength of the evidence that underlies conclusions to enable decision makers to use them effectively. In 2007, AHRQ supported a cross-EPC set of workgroups to develop guidance on major elements of designing, conducting, and reporting CERs. This paper reports the outcomes of the EPC workgroup on grading strength of evidence. We briefly explore the rationale for grading strength of evidence, define the domains of concern for evidence strength, and describe our recommended grading system for such reviews. Our main objective was to give guidance to EPCs for grading strength of evidence in CERs, but this guidance may also apply to other systematic reviews.