A nested case-control study is conducted within a large prospective cohort. Compared to a conventional case-control study, the key methodological advantage of the nested design is:

• A Exposure data are collected prospectively before disease onset, eliminating recall bias ✓
• B A larger sample size is always obtained
• C Relative risk can be directly calculated without assumptions
• D Blinding of participants is more readily achieved

Explanation

In a nested case-control study, the source cohort has already been enrolled and baseline exposures measured prospectively; cases arise from follow-up and controls are matched from the same cohort. Because exposure data precede disease onset, recall bias is eliminated and temporality is preserved—an advantage over conventional case-controls relying on retrospective recall. While RR cannot be directly calculated (OR is still the measure), the density-sampling OR approximates the rate ratio closely. Sample size and blinding advantages are not inherent to the nested design.

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.