A Retrospective Controlled Cohort Study is a type of observational study in which researchers look back in time (using existing data) to compare outcomes between two or more predefined groups (cohorts) based on their exposure or treatment status.
Key Features:
Retrospective study: The study uses past records or data (e.g., medical charts, registries) to identify both exposures and outcomes.
Controlled study: There is a comparison group—often a control cohort that did not receive the intervention or exposure of interest.
Cohort study: Participants are grouped based on a shared characteristic or exposure, such as having received a particular treatment.
Temporal relationship: The exposure precedes the outcome, but both have already occurred at the time of study initiation.