Analysis of homogeneity of treatment effect in adaptive multicenter clinical trials.

In this paper, an exact test for analyzing the homogeneity of treatment effect in adaptive multicenter clinical trials is proposed. Extensive simulation studies are performed to investigate the large sample behavior of a commonly used test statistic for testing homogeneity of treatment effect. When the sample size in each center is large relative to the number of centers, the asymptotic null distribution of the test statistic is reasonable. On the other hand, when the data are relatively sparse, the proposed exact test should be used to incorporate the adaptive nature of the design.