title: Analyses of group sequential clinical trials.
abstract: In the first part of this article the methodology of group sequential plans is reviewed. After introducing the basic definition of such plans the main properties are shown. At the end of this section three different plans (Pocock, O'Brien-Fleming, Koepcke) are compared. In the second part of the article some unresolved issues and recent developments in the application of group sequential methods to long-term controlled clinical trials are discussed. These include deviation from the assumptions, life table methods, multiple-arm clinical trials, multiple outcome measures, and confidence intervals.
authors.affiliation: Biometric Center for Therapeutic Studies, Munich, West Germany.
authors.forename: W
authors.initials: W
authors.lastname: Koepcke
mesh_terms: D000206:Actuarial Analysis; D016001:Confidence Intervals; D006801:Humans; D015233:Models, Statistical; D009874:Operations Research; D010043:Outcome and Process Assessment, Health Care / Q000379:methods; D010934:Planning Techniques; D011382:Programming, Linear; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D012494:Sampling Studies