Examining whether treatment effects differ across predefined patient subsets within a study.
A subgroup analysis re-examines outcomes within a subset of trial participants (e.g., by age, sex, injury severity, or baseline scores) rather than the whole sample, to see if the intervention effect varies by that characteristic. These analyses are useful for generating hypotheses but are prone to false positives when unplanned or numerous, so findings should be treated as exploratory unless the subgroup was pre-specified and the study was powered for it. Clinicians should be cautious about changing practice based on subgroup findings alone without confirmatory research.
This guide was auto-drafted and is pending editorial review.