title: Construction of group sequential designs in clinical trials on the basis of detectable treatment differences.
abstract: The treatment effect sizes that can be detected with sufficient power up to the different interim analyses constitute a clinically meaningful criterion for the selection of a group sequential test for a clinical trial. For any pre-specified sequence of effect sizes, it is possible to construct group sequential boundaries such that the trial has a pre-specified power to reject the null-hypothesis at or before the corresponding interim analysis under the respective treatment effect. The principle of constructing group sequential designs on the basis of detectable treatment effects is presented. The application in common situations such as two-armed trials with continuous or binary outcome or censored survival times is described. We also present an effective algorithm.
authors.affiliation: Institute of Medical Biometry and Epidemiology, Philipps-University Marburg, Bunsenstrabetae 3, D-35037 Marburg, Germany. hsimbe@mailer.uni-marburg.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Schäfer
authors.forename: Hans-Helge
authors.initials: HH
authors.lastname: Müller
mesh_terms: D000465:Algorithms; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000628:therapy; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D003661:Decision Support Techniques; D004558:Electric Stimulation; D006801:Humans; D008175:Lung Neoplasms; D015233:Models, Statistical; D010300:Parkinson Disease / Q000628:therapy; D011788:Quality of Life; D012107:Research Design / Q000706:statistics & numerical data*; D018401:Sample Size; D015996:Survival Rate