Cardiovascular prevention: population versus high-risk strategy: 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 · Cardiovascular prevention: population versus high-risk strategy

Sample item

In a town of 10,000 adults, 1,000 are in a high-risk group with a yearly cardiovascular event risk of 10%, and 9,000 are at lower risk with a yearly event risk of 2%. Which strategy and reasoning best fits the situation?

APopulation strategy, since the lower-risk majority produces 180 of the 280 eventsBHigh-risk strategy, since both groups produce equal numbers of eventsCPopulation strategy, since the high-risk group produces 180 of the 280 eventsDHigh-risk strategy, since the high-risk group produces most of the events

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

The answer and the reasoning

A. Population strategy, since the lower-risk majority produces 180 of the 280 events

The high-risk group has 1,000 x 0.10 = 100 events and the lower-risk majority has 9,000 x 0.02 = 180 events. This is Rose's prevention paradox: a large number of people at small risk give rise to more cases than a small number at high risk. A population strategy that shifts the whole risk distribution is needed alongside the high-risk strategy.

Option by option

A. Population strategy, since the lower-risk majority produces 180 of the 280 events (correct)
Correct. The majority at low individual risk generates 180 of 280 events.
B. High-risk strategy, since both groups produce equal numbers of events
The groups produce 100 and 180 events, which are not equal.
C. Population strategy, since the high-risk group produces 180 of the 280 events
The numbers are attributed to the wrong group; the 180 events come from the lower-risk group.
D. High-risk strategy, since the high-risk group produces most of the events
The high-risk group generates only 100 of the 280 events despite its higher individual risk.

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 A, Population strategy, since the lower-risk majority produces 180 of the 280 events. The high-risk group has 1,000 x 0.

Why is "High-risk strategy, since both groups produce equal numbers of events" not the answer?

The groups produce 100 and 180 events, which are not equal.

Why is "Population strategy, since the high-risk group produces 180 of the 28…" not the answer?

The numbers are attributed to the wrong group; the 180 events come from the lower-risk group.

Why is "High-risk strategy, since the high-risk group produces most of the ev…" not the answer?

The high-risk group generates only 100 of the 280 events despite its higher individual risk.

What concept does this question test?

It tests Cardiovascular prevention: population versus high-risk strategy in PSM. 10 = 100 events and the lower-risk majority has 9,000 x 0.02 = 180 events. This is Rose's prevention paradox: a large number of people at small risk give rise to more cases than a small number at high risk. A population strategy that shifts the whole risk distribution is needed alongside the high-risk strategy.

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 Cardiovascular prevention: population versus high-risk strategy?

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.