In a cohort of asbestos miners, 60 deaths due to respiratory cancer occurred during the study period, whereas only 40 deaths would have been expected based on age-specific mortality rates of the general male population. The Standardized Mortality Ratio (SMR) is:

• A 0.67, indicating lower mortality than the general population
• B 2.5, indicating a 150% excess mortality
• C 150, indicating a 150-fold increase in mortality
• D 1.5, indicating a 50% excess mortality ✓

Explanation

SMR equals observed deaths divided by expected deaths, expressed as a percentage: (60/40) x 100 = 150. This means the cohort experienced 50% more respiratory cancer deaths than expected after adjustment for age structure. Option C misreads the percentage point value as a fold-change, and option B incorrectly computes excess as a proportion of observed rather than expected deaths.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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