Ahn, Chul; Heo, Moonseoung; Zhang, Song; Kim, Mimi

Sample Size Calculations for Clustered and Longitudinal Outcomes in Clinical Research

Sample size calculation is an important component at the design stage of clinical trials, health outcomes, and behavioral research. This book deals with how to estimate sample size for correlated outcomes, such as clustered data and longitudinal data. It provides sample size formulas incorporating intracluster correlation and the variability in cluster sizes. It also describes how missing data and correlation structures affect the sample size estimates in longitudinal data using generalized estimating equation (GEE) and mixed model approaches.