Sample Size Calculations for Partially Clustered Trials.

ABSTRACT: Partially clustered trials are defined as trials where some observations belong to a cluster and others are independent. For example, neonatal trials may include infants from a single, twin, or triplet birth. The clustering of observations in partially clustered trials should be accounted for when determining the target sample size to avoid being over or underpowered. However, sample size methods have only been developed for limited partially clustered trial designs (e.g., designs with maximum cluster sizes of 2). In this article, we present new design effects that can be used to determine the sample size for two-arm, parallel, partially clustered trials where clusters exist pre-randomization. Design effects are derived algebraically for continuous and binary outcomes, assuming a generaliz

SUBMITTER: Lange KM 

PROVIDER: S-EPMC12261973 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature