Sample size calculation for cluster randomization trials with a time-to-event endpoint.

TitleSample size calculation for cluster randomization trials with a time-to-event endpoint.
Publication TypeJournal Article
Year of Publication2020
AuthorsLi, Jianghao, and Sin-Ho Jung
JournalStat Med
Volume39
Issue25
Pagination3608-3623
Date Published2020 11 10
ISSN1097-0258
KeywordsCluster Analysis, Computer Simulation, Humans, Random Allocation, Randomized Controlled Trials as Topic, Research Design, Sample Size
Abstract

Cluster randomization trials randomize groups (called clusters) of subjects (called subunits) between intervention arms, and observations are collected from each subject. In this case, subunits within each cluster share common frailties, so that the observations from subunits of each cluster tend to be correlated. Oftentimes, the outcome of a cluster randomization trial is a time-to-event endpoint with censoring. In this article, we propose a closed form sample size formula for weighted rank tests to compare the marginal survival distributions between intervention arms under cluster randomization with possibly variable cluster sizes. Extensive simulation studies are conducted to evaluate the performance of our sample size formula under various design settings. Real study examples are taken to demonstrate our method.

DOI10.1002/sim.8683
Alternate JournalStat Med
Original PublicationSample size calculation for cluster randomization trials with a time-to-event endpoint.
PubMed ID33463748
Grant ListCA142538-01 / CA / NCI NIH HHS / United States