Social and Behavioral Sciences Commons^™

Required Sample Size To Detect Mediation In 3-Level Implementation Studies, Nathaniel J. Williams, Kristopher J. Preacher, Paul D. Allison, David S. Mandell, Steven C. Marcus

Social Work Faculty Publications and Presentations

Background: Statistical tests of mediation are important for advancing implementation science; however, little research has examined the sample sizes needed to detect mediation in 3-level designs (e.g., organization, provider, patient) that are common in implementation research. Using a generalizable Monte Carlo simulation method, this paper examines the sample sizes required to detect mediation in 3-level designs under a range of conditions plausible for implementation studies.

Method: Statistical power was estimated for 17,496 3-level mediation designs in which the independent variable (X) resided at the highest cluster level (e.g., organization), the mediator (M) resided at the intermediate …