An investigator wants to compare lung cancer mortality between workers of a chemical factory and the general population. Age-specific death rates are available for the factory workers, but the age-specific death rates for lung cancer in the national population are not available; only the overall national lung cancer death rate and the age structure of the two populations are known. Which method of standardisation should the investigator use?

• A Direct standardisation
• B Indirect standardisation ✓
• C No standardisation is possible in this situation
• D Standardisation by calculating the case fatality rate

Explanation

Indirect standardisation is used when age-specific death rates for the standard population are not available. The investigator applies the known overall standard rate to the study population's age structure to obtain expected deaths, then computes the Standardised Mortality Ratio (observed divided by expected deaths). Direct standardisation requires age-specific rates for all populations being compared and cannot be performed here.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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