Among miners exposed to silica dust, 60 deaths from tuberculosis were observed during the study period. Based on age-specific mortality rates of the national population applied to this cohort, 40 tuberculosis deaths were expected. The standardized mortality ratio (SMR) is:

• A 150, indicating mortality 50% higher than the general population ✓
• B 66, indicating mortality 34% lower than the general population
• C 120, indicating mortality 20% higher than the general population
• D 240, indicating mortality 2.4 times that of the general population

Explanation

SMR is calculated as (observed deaths divided by expected deaths) multiplied by 100, here (60/40) x 100 = 150. An SMR of 150 means the cohort experiences 50% excess mortality from the cause studied relative to the standard population after adjusting for age structure. Option D confuses the ratio with its percentage expression, while options B and C reflect arithmetic slips in the observed-to-expected division.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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