In an occupational cohort study of miners, 60 deaths due to respiratory disease were observed during the study period, while only 40 such deaths were expected based on age-specific mortality rates of the general population. The Standardized Mortality Ratio is:
- A 66%
- B 100
- C 150 ✓
- D 240
Correct answer: C. 150
Explanation
SMR is calculated as (observed deaths divided by expected deaths) multiplied by 100. Here, 60 divided by 40 equals 1.5, so SMR is 150. This means the study population experienced 50% excess mortality compared with what would be expected if it had the same age-specific death rates as the reference population. Option A results from inverting the ratio, and option D comes from adding rather than multiplying by 100.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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