A study appearing in the August 13 issue of the Journal of the American Medical Association (JAMA) reports that estimating treatment outcomes in metaanalyses may differ depending on the analysis strategy used, and may greatly affect the conclusions drawn from the analysis. In an accompanying editorial, journal editors write that the findings deserve consideration not only in the planning of the studies but in the journal peer review and evaluation.
Meta-analyses of randomized clinical trials are generally considered to provide among the best evidence of efficacy of medical interventions. They should be conducted as part of a systematic review, a scientifically rigorous approach that identifies, selects, and appraises all relevant studies. Which trials to combine in a metaanalysis remains a persistent dilemma, according to the authors. A news story about the research, with link to the journal abstract, may be read here.