Sample size determination for GEE analyses of stepped wedge cluster randomized trials.

ABSTRACT: In stepped wedge cluster randomized trials, intact clusters of individuals switch from control to intervention from a randomly assigned period onwards. Such trials are becoming increasingly popular in health services research. When a closed cohort is recruited from each cluster for longitudinal follow-up, proper sample size calculation should account for three distinct types of intraclass correlations: the within-period, the inter-period, and the within-individual correlations. Setting the latter two correlation parameters to be equal accommodates cross-sectional designs. We propose sample size procedures for continuous and binary responses within the framework of generalized estimating equations that employ a block exchangeable within-cluster correlation structure defined from the distinc

SUBMITTER: Li F 

PROVIDER: S-EPMC6461045 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature