Explaining the variation in the attained power of a stepped-wedge trial with unequal cluster sizes.

ABSTRACT:

Background

In a cross-sectional stepped-wedge trial with unequal cluster sizes, attained power in the trial depends on the realized allocation of the clusters. This attained power may differ from the expected power calculated using standard formulae by averaging the attained powers over all allocations the randomization algorithm can generate. We investigated the effect of design factors and allocation characteristics on attained power and developed models to predict attained power based on allocation characteristics.

Method

Based on data simulated and analyzed using linear mixed-effects models, we evaluated the distribution of attained powers under different scenarios with varying intraclass correlation coefficient (ICC) of the responses, coefficient of variation (CV) of th

SUBMITTER: Ouyang Y 

PROVIDER: S-EPMC7315519 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature