Epidemiology: indirect standardisation: practice question

A PSM question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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PSM · Epidemiology: indirect standardisation

Sample item

A small mining town of 4,000 people has an accurate count of total deaths but too few deaths in each age group to give stable age-specific death rates. To compare its mortality with the state while adjusting for age, which method is appropriate?

ADirect standardisation using a standard populationBCalculation of proportionate mortalityCComparison of crude death ratesDIndirect standardisation giving a standardised mortality ratio

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Indirect standardisation giving a standardised mortality ratio

Indirect standardisation applies the age-specific death rates of a reference population to the age structure of the study population to get expected deaths, and the ratio of observed to expected deaths is the standardised mortality ratio. It is used when age-specific rates of the study population are unavailable or unstable.

Option by option

A. Direct standardisation using a standard population
Direct standardisation needs reliable age-specific rates from the study population, which are not available here.
B. Calculation of proportionate mortality
Proportionate mortality is the share of deaths from one cause and is not an age-adjusted measure of overall mortality.
C. Comparison of crude death rates
Crude death rates take no account of the differing age structures of the two populations.
D. Indirect standardisation giving a standardised mortality ratio (correct)
Correct. Expected deaths from state rates are compared with observed deaths, and no age-specific rates are needed from the town.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this PSM question

What is the answer to this PSM question?

The best answer is D, Indirect standardisation giving a standardised mortality ratio. Indirect standardisation applies the age-specific death rates of a reference population to the age structure of the study population to get expected deaths, and the ratio of observed to expected deaths is the standardised mortality ratio.

Why is "Direct standardisation using a standard population" not the answer?

Direct standardisation needs reliable age-specific rates from the study population, which are not available here.

Why is "Calculation of proportionate mortality" not the answer?

Proportionate mortality is the share of deaths from one cause and is not an age-adjusted measure of overall mortality.

Why is "Comparison of crude death rates" not the answer?

Crude death rates take no account of the differing age structures of the two populations.

What concept does this question test?

It tests Epidemiology: indirect standardisation in PSM. It is used when age-specific rates of the study population are unavailable or unstable.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Epidemiology: indirect standardisation?

Practise biostatistics with small calculations until sensitivity, predictive values and risk measures are automatic. Then use the flashcards and the other PSM questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.