title: Release of data from an ongoing randomized clinical trial for sample size adjustment or planning.
abstract: The determination of an appropriate sample size is a key issue in planning and designing randomized clinical trials. In settings with time-to-event or binary outcomes, the required sample size depends on the control-arm event (response) rate. An accurate estimate of this rate is not often available at the planning stage. Therefore, non-comparative control-arm or pooled-arm event rates from an ongoing trial are sometimes released for sample size adjustment or planning purposes. It is shown that such non-comparative data release may still contain information on the relative treatment benefit and may thus adversely affect the ongoing trial. A simple approach to minimizing the effect of the data release is suggested.
authors.affiliation: Biometric Research Branch, EPN-8122, National Cancer Institute, Bethesda, MD 20892-7434, USA. freidlinb@ctep.nci.nih.gov
authors.forename: Boris
authors.initials: B
authors.lastname: Freidlin
authors.forename: Edward L
authors.initials: EL
authors.lastname: Korn
mesh_terms: D001499:Bayes Theorem; D001699:Biometry; D006801:Humans; D033181:Information Dissemination; D016032:Randomized Controlled Trials as Topic / Q000592:standards / Q000706:statistics & numerical data; D012107:Research Design; D018401:Sample Size; D014481:United States