A matched case-control study for a rare disease (prevalence 0.5%) is designed with 1 case per 4 matched controls. This matching strategy is MOST appropriately analysed using:
- A McNemar's test or conditional logistic regression accounting for the matched design ✓
- B Unmatched chi-square test
- C Pearson's correlation coefficient
- D Independent samples t-test
Correct answer: A. McNemar's test or conditional logistic regression accounting for the matched design
Explanation
Matched case-control data have within-stratum (matched set) correlation that violates the independence assumption of standard chi-square tests. McNemar's test is used for 1:1 matched case-control; conditional logistic regression is used for R:1 matched designs (including 1:4 matching). Ignoring the matched structure and using unmatched analysis inflates the effective sample size and produces incorrect standard errors.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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