title: In the era of systematic reviews, does the size of an individual trial still matter.
abstract: Systematic reviews that combine high-quality evidence from several trials are now widely considered to be at the top of the hierarchy of clinical evidence. Given the primacy of systematic reviews-and the fact that individual clinical trials rarely provide definitive answers to a clinical research question-some commentators question whether the sample size calculation for an individual trial still matters. Others point out that small trials can still be potentially misleading.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. guyatt@mcmaster.ca
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Mills
authors.forename: Diana
authors.initials: D
authors.lastname: Elbourne
mesh_terms: D002986:Clinical Trials as Topic; D003627:Data Interpretation, Statistical; D006801:Humans; D012196:Review Literature as Topic; D018401:Sample Size