Subgroup Analyses in Stepped-Wedge Cluster Randomized Trials: A Systematic Review of Statistical Practice and Reporting from 2016 to 2023.
OBJECTIVE Subgroup analyses can inform whether intervention effects differ systematically across participants, but they are prone to false-positive findings, low power, and selective reporting. Stepped-wedge cluster randomized trials (SW-CRTs) introduce additional inferential complexities (e.g., time effects, clusterin...