Group sequential testing for cluster randomized trials with time‐to‐event endpoint. Issue 4 (13th June 2021)

• Record Type: Journal Article
• Authors: Li, Jianghao; Jung, Sin‐Ho
• Is Part Of: Biometrics. Volume 78:Issue 4(2022)
• Page Start: 1353
• Page End: 1364
• Publication Date: 2021-06-13
• Subjects: alpha spending function -- dependent increment -- expected sample size -- intracluster correlation coefficient -- log‐rank test -- variable cluster size; Biometry -- Periodicals; 570.15195
• DOI: 10.1111/biom.13498
• Languages: English
• ISSNs: 0006-341X

Abstract

Abstract: We propose group sequential methods for cluster randomized trials (CRTs) with time‐to‐event endpoint. The alpha spending function approach is used for sequential data monitoring. The key to this approach is determining the joint distribution of test statistics and the information fraction at the time of interim analysis. We prove that the sequentially computed log‐rank statistics in CRTs do not have independent increment property. We also propose an information fraction for group sequential trials with clustered survival data and a corresponding sample size determination approach. Extensive simulation studies are conducted to evaluate the performance of our proposed testing procedure using some existing alpha spending functions in terms of expected sample size and maximal sample size. Real study examples are taken to demonstrate our method.