Within an ongoing cohort of 50,000 adults with stored baseline blood samples, a researcher identifies all incident cases of rheumatoid arthritis over 8 years and selects four non-cases per case from the same cohort, then measures baseline vitamin D levels. Which design has been used?
- A Classic case-control study
- B Case-cohort study
- C Nested case-control study ✓
- D Case-crossover study
Correct answer: C. Nested case-control study
Explanation
A nested case-control study samples cases and matched controls from within a defined cohort, using exposure data collected before disease onset. It retains the temporal advantage of a cohort while costing far less than assaying the whole cohort. A classic case-control draws cases and controls from outside any single cohort, a case-cohort samples the comparison group from the entire cohort at baseline irrespective of future status, and case-crossover uses subjects as their own controls.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.