title: p-value adjustments for subgroup analyses.
abstract: The analysis of data from clinical trials often includes subgroup analyses, which are performed to examine the treatment effect within various sets of patients based on baseline and/or demographic variables. The goals of these analyses are to establish the consistency of the results across the subgroups and to identify important prognostic factors. The p-values for such analyses are usually presented without any adjustment for the multiple analyses: This approach has been criticized because of the possibility of misleading false positives. Conservative approaches have been proposed to resolve this problem; however, these approaches are usually so conservative that significant results are rarely observed after adjustment. Here an approximate technique for use when the variable of interest has a normal distribution is presented.
authors.affiliation: Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Bristol
mesh_terms: D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D016011:Normal Distribution; D012107:Research Design; D012959:Socioeconomic Factors