In a community survey, the odds ratio for developing dengue among households with overhead tanks versus piped supply is 3.2, and the prevalence of overhead tank use is 40%. The population attributable risk percent (PAR%) is approximately:

• A 34%
• B 57%
• C 68%
• D 47% ✓

Explanation

PAR% = [Pe(RR−1)] / [1 + Pe(RR−1)] × 100, where Pe = prevalence of exposure = 0.4 and RR ≈ OR = 3.2. Numerator: 0.4 × (3.2−1) = 0.4 × 2.2 = 0.88. Denominator: 1 + 0.88 = 1.88. PAR% = 0.88/1.88 × 100 = 46.8% ≈ 47%. This figure represents the proportion of dengue in the community attributable to overhead tank use. Options A (34%), C (57%) and D (68%) result from incorrect substitutions in the formula.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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