A case-control study calculates an Odds Ratio of 3.2 for the association between alcohol use and oesophageal cancer. The Population Attributable Risk Percent (PAR%) in a population with 30% alcohol exposure prevalence is closest to:
- A 36%
- B 41% ✓
- C 27%
- D 52%
Correct answer: B. 41%
Explanation
PAR% = Pe(RR – 1) / [Pe(RR – 1) + 1] × 100, where Pe = prevalence of exposure in population = 0.30 and RR ≈ OR = 3.2. PAR% = 0.30 × (3.2 – 1) / [0.30 × (3.2 – 1) + 1] × 100 = 0.30 × 2.2 / [0.66 + 1] × 100 = 0.66 / 1.66 × 100 = 39.76% ≈ 41% (closest option). PAR% estimates the proportion of disease in the population attributable to the exposure and guides public health priority-setting.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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