Introduction to Trial‐Level Subgroup Analysis: A Tutorial

Abstract

ABSTRACT This tutorial introduces the concept of trial‐level subgroup analysis in meta‐analysis. We describe the rationale for conducting subgroup analyses, distinguish trial‐level from participant‐level characteristics, outline how to properly interpret effects within subgroups, and illustrate how to perform a trial‐level subgroup analysis, including formal statistical testing for differences between subgroups. A complementary micro‐learning module is provided to support additional learning of these concepts.