Sample size and power calculations for open cohort longitudinal cluster randomized trials.

ABSTRACT: When calculating sample size or power for stepped wedge or other types of longitudinal cluster randomized trials, it is critical that the planned sampling structure be accurately specified. One common assumption is that participants will provide measurements in each trial period, that is, a closed cohort, and another is that each participant provides only one measurement during the course of the trial. However some studies have an "open cohort" sampling structure, where participants may provide measurements in variable numbers of periods. To date, sample size calculations for longitudinal cluster randomized trials have not accommodated open cohorts. Feldman and McKinlay (1994) provided some guidance, stating that the participant-level autocorrelation could be varied to account for the degr

SUBMITTER: Kasza J 

PROVIDER: S-EPMC7217159 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature