Sample size determination for mediation analysis of longitudinal data.

ABSTRACT:

Background

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design.

Methods

To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product

SUBMITTER: Pan H 

PROVIDER: S-EPMC5870539 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature