Conducting Quantitative Synthesis When Comparing Medical Interventions: AHRQ and the Effective Health Care Program. Methods Guide for Comparative Effectiveness Reviews

摘要

Comparative effectiveness reviews (CERs) are systematic reviews that summarize comparative effectiveness and harms of alternative clinical options, and aim to help clinicians, policy makers, and patients make informed treatment choices. Quantitative synthesis, or metaanalysis, is often essential for CERs to provide scientifically rigorous summary information. Quantitative synthesis should be conducted in a transparent and consistent way, and methodologies reported explicitly. Reasons for this were made clear during the controversy around the safety of rosiglitazone, where a systematic review that found increased risk for myocardial infarction1 spurred heated debate on issues around choosing appropriate methods for quantitative syntheses; and the subsequent Congressional hearing brought these issues further into spotlight. This story highlighted the fact that basic issues in quantitative syntheses, such as choice of an effect measure or a model or how to handle heterogeneity, remain crucial considerations and are often the subject of controversy and debate. A CER typically evaluates the evidence on multiple alternative interventions whereas most published meta-analyses compared one intervention with a placebo. Inclusion of multiple interventions increases the complexity of quantitative synthesis and entails methods of comparing multiple interventions simultaneously. Evaluation of multiple interventions also makes the assessment of similarity among studies and the decision to combine studies even more challenging. Presenting results of a meta-analysis from a CER in a way that is useful to decisionmakers is also a challenge.