title: Meta-analysis and evidence.
abstract: Meta-analysis is the science of combining evidence from different studies, but traditional statistical techniques contain neither a formal definition nor a measure of evidence. It is argued in this paper that the log-likelihood ratio, as a measure of the "weight of evidence," can be a very useful tool in the meta-analysis. The mathematics and the philosophy behind the use of this index are introduced. The construction and interpretation of "support curves" in fixed and random-effects models are presented. The application of evidential techniques is illustrated on six trials of aspirin therapy previously presented by Canner. The possible dangers of focusing on statistical error rates instead of evidence are discussed.
authors.affiliation: Department of Oncology, Johns Hopkins University, Baltimore, Maryland.
authors.forename: S N
authors.initials: SN
authors.lastname: Goodman
mesh_terms: D001241:Aspirin / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D003627:Data Interpretation, Statistical; D006801:Humans; D015201:Meta-Analysis as Topic; D015233:Models, Statistical; D009203:Myocardial Infarction / Q000401:mortality
chemical_list: D001241:Aspirin