A study that looks back at existing data to compare outcomes between exposed and unexposed groups.
An observational design in which a group (cohort) is identified and its exposure status determined from records or historical data, then followed backward in time to see whether outcomes (e.g. injury, re-op, return to sport) differed between exposed and unexposed subgroups. Because exposure and outcome have already occurred by the time the study starts, it is cheaper and faster than a prospective cohort but more vulnerable to selection bias, recall/records bias, and incomplete or inconsistent data capture. Useful for generating hypotheses or examining rarer outcomes, but causal claims should be made cautiously.
This guide was auto-drafted and is pending editorial review.