title: Bayesian monitoring of clinical trials with failure-time endpoints.
abstract: This article presents an aid for monitoring clinical trials with failure-time endpoints based on the Bayesian nonparametric analyses of the data. The posterior distribution is a mixture of Dirichlet processes in the presence of censoring if one assumes a Dirichlet process prior for the survival distribution. Using Gibbs sampling, one can generate random samples from the posterior distribution. With samples from the posterior distributions of treatment-specific survival curves, one can evaluate the current evidence in favor of stopping or continuing the trial based on summary statistics of these survival curves. Because the method is nonparametric, it can easily be used, for example, in situations where hazards cross or are suspected to cross and where relevant clinical decisions might be based on estimating when the integral between the curves might be expected to become positive and in favor of the new but toxic therapy. An example based on an actual trial illustrates the method.
authors.affiliation: Department of Biostatistics and Applied Mathematics, M. D. Anderson Cancer Center, The University of Texas, 1515 Holcombe Boulevard, Unit 447, Houston, Texas 77030, USA. glr@odin.mdacc.tmc.edu
authors.forename: Gary L
authors.initials: GL
authors.lastname: Rosner
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001499:Bayes Theorem; D001699:Biometry; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality; D002986:Clinical Trials as Topic / Q000379:methods; D005260:Female; D006801:Humans; D015233:Models, Statistical; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D017211:Treatment Failure
chemical_list: D000970:Antineoplastic Agents