title: A logrank test-based method for sizing clinical trials with two co-primary time-to-event endpoints.
abstract: We discuss sample size determination for clinical trials evaluating the joint effects of an intervention on two potentially correlated co-primary time-to-event endpoints. For illustration, we consider the most common case, a comparison of two randomized groups, and use typical copula families to model the bivariate endpoints. A correlation structure of the bivariate logrank statistic is specified to account for the correlation among the endpoints, although the between-group comparison is performed using the univariate logrank statistic. We propose methods to calculate the required sample size to compare the two groups and evaluate the performance of the methods and the behavior of required sample sizes via simulation.
authors: Department of Mathematical Sciences, Hirosaki University Graduate School of Science and Technology, 3 Bunkyocho, Hirosaki, Aomori 036-8561, Japan. tomoyuki@cc.hirosaki-u.ac.jp
authors: Tomoyuki
authors: T
authors: Sugimoto
authors: Takashi
authors: T
authors: Sozu
authors: Toshimitsu
authors: T
authors: Hamasaki
authors: Scott R
authors: SR
authors: Evans
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D056808:Biostatistics; D002986:Clinical Trials as Topic / Q000379:methods* / Q000706:statistics & numerical data; D017326:Clinical Trials, Phase III as Topic / Q000379:methods / Q000706:statistics & numerical data; D023381:Endpoint Determination / Q000706:statistics & numerical data; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D006801:Humans; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic / Q000379:methods / Q000706:statistics & numerical data; D018401:Sample Size
chemical_list: D019380:Anti-HIV Agents
keywords: Bivariate dependence; Censored data; Copula model; Logrank statistic; Power