title: Group Sequential Design for Randomized Phase III Trials under the Weibull Model.
abstract: In this article, a parametric sequential test is proposed under the Weibull model. The proposed test is asymptotically normal with an independent increment structure. The sample size for a fixed sample test is derived for the purpose of group sequential trial design. In addition, a multi-stage group sequential procedure is given under the Weibull model by applying the Brownian motion property of the test statistic and sequential conditional probability ratio test methodology.
authors.affiliation: a Department of Biostatistics , St. Jude Children's Research Hospital , Memphis , Tennessee , USA.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Wu
authors.affiliation: a Department of Biostatistics , St. Jude Children's Research Hospital , Memphis , Tennessee , USA.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xiong
mesh_terms: D000465:Algorithms; D002648:Child; D017326:Clinical Trials, Phase III as Topic / Q000706:statistics & numerical data*; D003198:Computer Simulation; D018572:Disease-Free Survival; D057239:Early Termination of Clinical Trials; D006801:Humans; D015233:Models, Statistical; D011336:Probability; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D012107:Research Design; D018335:Rhabdoid Tumor / Q000188:drug therapy / Q000401:mortality; D018401:Sample Size
keywords: Brownian motion; Group sequential trial; Randomized clinical trial; Sample size; Time-to-event; Weibull distribution