Statistics in clinical trials.

Statistical developments over the past several years are described in this review. Efforts in phase I studies have focused on efficient estimation of maximum tolerated dose. Issues investigated for phase II trials include incorporation of multiple endpoints and randomization. For phase III trials, methods to reduce time or use the sample size more efficiently have been investigated. However, design innovations come with costs, including possible increased risk of incorrect conclusions. Other recent challenging statistical developments in clinical trials relate to use of complementary outcomes such as quality of life and to associated biologic questions, including the emergence of the field of genomics.