title: Interaction between prognostic factors and treatment.
abstract: In randomized trials, the better therapy may depend on values of a prognostic factor. This article presents methodology for subdividing a target population into three subsets: one region of superiority of each treatment, and one region of uncertainty. The basis of such a subdivision is treatment by prognostic factor interaction. The importance of this analysis in group trial sequences is discussed briefly.
mesh_terms: D002986:Clinical Trials as Topic; D004358:Drug Therapy; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy; D011379:Prognosis; D012107:Research Design; D013223:Statistics as Topic