Statistical Issues in Clinical Trials with Multiple Primary Endpoints

Abstract

Clinical trials often employ two or more primary endpoints because a single endpoint may not provide a comprehensive picture of the intervention's effects. In such clinical trials, a decision is generally made as to whether it is desirable to evaluate the joint effects on all endpoints (i.e., co-primary endpoints) or at least one of the endpoints. This decision defines the alternative hypothesis to be tested and provides a framework for approaching trial design. In this article, we discuss recent statistical issues in clinical trials with multiple primary endpoints. Especially, we introduce the methods for power and sample size determinations in clinical trials with co-primary endpoints, considering the correlations among the endpoints into the calculations. We also discuss the methods to alleviate conservativeness of testing co-primary endpoints.