Relative efficiency of unequal versus equal cluster sizes in cluster randomized trials using generalized estimating equation models.

ABSTRACT: There is growing interest in conducting cluster randomized trials (CRTs). For simplicity in sample size calculation, the cluster sizes are assumed to be identical across all clusters. However, equal cluster sizes are not guaranteed in practice. Therefore, the relative efficiency (RE) of unequal versus equal cluster sizes has been investigated when testing the treatment effect. One of the most important approaches to analyze a set of correlated data is the generalized estimating equation (GEE) proposed by Liang and Zeger, in which the "working correlation structure" is introduced and the association pattern depends on a vector of association parameters denoted by ρ. In this paper, we utilize GEE models to test the treatment effect in a two-group comparison for continuous, binary, or count d

SUBMITTER: Liu J 

PROVIDER: S-EPMC6760674 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature