In a cohort of asbestos miners, 60 deaths from lung cancer occurred over the study period, whereas only 40 such deaths were expected if national age-specific mortality rates applied. The standardized mortality ratio (SMR) is:
- A 0.67 or 67%
- B 1.5 or 150% ✓
- C 2.5 or 250%
- D 20 excess deaths per 1000 population
Correct answer: B. 1.5 or 150%
Explanation
SMR equals observed deaths divided by expected deaths, multiplied by 100. Here 60 divided by 40 times 100 gives 150%, meaning lung cancer mortality in the miners is 1.5 times what would be expected using national age-specific rates. Option A incorrectly divides expected by observed, and option D describes an absolute excess measure rather than a ratio.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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