1. Identification of Cases: In a nested case-control study, cases (individuals who develop the outcome of interest) are identified from the parent cohort. 2. Selection of Controls: Controls (individuals who do not develop the outcome) are then matched to the cases based on certain criteria such as age, sex, or other variables. 3. Exposure Assessment: The exposure status of both cases and controls is determined using the data collected at baseline or during follow-up periods.
