Study designs: 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 · Study designs

Sample item

Which study design is usually most efficient for examining a rare disease?

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

The answer and the reasoning

C. Case-control study

Case-control studies begin with people who have and do not have a rare outcome, then compare prior exposures, making them efficient when waiting for enough incident cases in a cohort would be impractical.

Option by option

  • A. Cross-sectional prevalence survey only

    Cross-sectional surveys measure prevalence but have limited temporal inference.

  • B. Randomized trial of every possible exposure

    Randomizing every exposure is usually infeasible and unethical.

  • C. Case-control study (correct)

    Correct: case-control designs are efficient for rare outcomes.

  • D. Ecological description only

    Ecological studies use group-level data and have different limitations.

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.

More PSM questions

Questions about this PSM question

What is the answer to this PSM question?

The best answer is C, Case-control study. Case-control studies begin with people who have and do not have a rare outcome, then compare prior exposures, making them efficient when waiting for enough incident cases in a cohort would be impractical.

Why is "Cross-sectional prevalence survey only" not the answer?

Cross-sectional surveys measure prevalence but have limited temporal inference.

Why is "Randomized trial of every possible exposure" not the answer?

Randomizing every exposure is usually infeasible and unethical.

Why is "Ecological description only" not the answer?

Ecological studies use group-level data and have different limitations.

What concept does this question test?

It tests Study designs in PSM. The correct option holds because: Correct: case-control designs are efficient for rare outcomes.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Study designs?

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.