Among miners studied over one year, 60 deaths were observed whereas 40 deaths were expected based on age-specific rates of the general male population. The Standardized Mortality Ratio (SMR) is:
- A 240, indicating a 140% excess mortality
- B 150%, indicating mortality equal to the general population
- C 150, indicating a 50% excess mortality ✓
- D 67, indicating lower mortality than expected
Correct answer: C. 150, indicating a 50% excess mortality
Explanation
SMR equals observed deaths divided by expected deaths multiplied by 100: 60/40 x 100 gives 150. An SMR above 100 means mortality exceeds what would be expected if the cohort had experienced the reference population's age-specific rates, here a 50% excess. Option B confuses the ratio with a percentage excess. Option A incorrectly divides expected by observed. Option D inverts the formula entirely.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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