Statistical heterogeneity in systematic reviews of clinical trials: a critical appraisal of guidelines and practice

作者：Julian P. T. Higgins, Simon Thompson, Jonathan J Deeks, Douglas G. Altman · 发表于：Journal of Health Services Research & Policy · 年份：2002 · DOI：10.1258/1355819021927674 · 被引用次数：770 · 研究领域：Meta-analysis and systematic reviews、Reliability and Agreement in Measurement、Biological Research and Disease Studies

OBJECTIVE: Heterogeneity between study results can be a problem in any systematic review or meta-analysis of clinical trials. Identifying its presence, investigating its cause and correctly accounting for it in analyses all involve difficult decisions for the researcher. Our objectives were: to collate recommendations on the subject of dealing with heterogeneity in systematic reviews of clinical trials; to investigate current practice in addressing heterogeneity in Cochrane reviews; and to compare current practice with recommendations. METHODS: We review guidelines for those undertaking systematic reviews and examine how heterogeneity is addressed in practice in a sample of systematic reviews, and their protocols, from the Cochrane Database of Systematic Reviews. RESULTS: Advice to reviewers is on the whole consistent and sensible. However, examination of a sample of Cochrane protocols and reviews demonstrates that the advice is difficult to follow given the small numbers of studies identified in many systematic reviews, the difficulty of pre-specifying important effect modifiers for subgroup analysis or meta-regression and the unresolved debate concerning fixed versus random effects meta-analyses. There was disagreement between protocols and reviews, often either regarding choice of important potential effect modifiers or due to the review identifying too few studies to perform planned analyses. CONCLUSION: Guidelines that address practical issues are required to reduce the ...