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Statistics in medicine
11 10, 2020;39 (25): 3608-3623.

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

Jianghao Li, Sin-Ho Jung
Author Information
  1. Jianghao Li: Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, USA.
  2. Sin-Ho Jung: Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, USA. ORCID
PMID: 33463748 DOI: 10.1002/sim.8683

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.

Keywords

censoring inflation factor intracluster correlation coefficient variable cluster size weighted rank test

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MeSH Term

Cluster Analysis
Computer Simulation
Humans
Random Allocation
Randomized Controlled Trials as Topic
Research Design
Sample Size
Journal Article Research Support, N.I.H., Extramural
Article has an altmetric score of 1

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