Asymptotic normality of urn models for clinical trials with delayed response

Abstract

For response-adaptive clinical trials using a generalized Friedman's urn design, we derive the asymptotic normality of the sample fraction assigned to each treatment under staggered entry and delayed response. The rate of convergence and the law of the iterated logarithm are obtained for both the urn composition and the sample fraction. Some applications are also discussed. © 2004 ISI/BS.