Biostatistics: 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 · Biostatistics

Sample item

A researcher doubles sample size to narrow the expected uncertainty around a prevalence estimate; which quantity is being improved?

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

The answer and the reasoning

B. Precision

Larger samples generally reduce sampling variability, producing narrower confidence intervals and therefore improving precision of an estimated population value.

Option by option

  • A. Case fatality

    Case fatality is a clinical outcome measure unrelated to estimate width.

  • B. Precision (correct)

    Correct: precision improves when sampling variability and confidence-interval width decrease.

  • C. Disease prevalence

    Disease prevalence is the measured frequency, not the uncertainty around it.

  • D. External validity

    External validity concerns applicability to other populations, not interval width.

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 B, Precision. Larger samples generally reduce sampling variability, producing narrower confidence intervals and therefore improving precision of an estimated population value.

Why is "Case fatality" not the answer?

Case fatality is a clinical outcome measure unrelated to estimate width.

Why is "Disease prevalence" not the answer?

Disease prevalence is the measured frequency, not the uncertainty around it.

Why is "External validity" not the answer?

External validity concerns applicability to other populations, not interval width.

What concept does this question test?

It tests Biostatistics in PSM. The correct option holds because: Correct: precision improves when sampling variability and confidence-interval width decrease.

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 Biostatistics?

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.