Study design: 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.

Try it

PSM · Study design

Sample item

Why are matching variables used in a case-control study?

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

The answer and the reasoning

C. Reduce confounding by selected factors

Matching makes cases and controls similar for selected variables such as age or sex, reducing confounding when analysed appropriately.

Option by option

  • A. Eliminate need for controls

    Controls remain essential.

  • B. Increase outcome misclassification

    It should improve rather than worsen classification.

  • C. Reduce confounding by selected factors (correct)

    Correct: matching addresses selected confounders.

  • D. Measure incidence directly

    Case-control studies do not directly measure incidence.

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, Reduce confounding by selected factors. Matching makes cases and controls similar for selected variables such as age or sex, reducing confounding when analysed appropriately.

Why is "Eliminate need for controls" not the answer?

Controls remain essential.

Why is "Increase outcome misclassification" not the answer?

It should improve rather than worsen classification.

Why is "Measure incidence directly" not the answer?

Case-control studies do not directly measure incidence.

What concept does this question test?

It tests Study design in PSM. The correct option holds because: Correct: matching addresses selected confounders.

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 design?

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.