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

What is statistical power in a clinical study?

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

The answer and the reasoning

B. Probability of detecting a true effect when it exists

Power is the probability a study will reject the null hypothesis when a real effect exists, and it rises with larger sample size and effect size.

Option by option

  • A. Probability that null hypothesis is true

    Null truth is not estimated by power.

  • B. Probability of detecting a true effect when it exists (correct)

    Correct: power protects against Type II false-negative error.

  • C. Proportion of false-positive results

    False positives relate to Type I error.

  • D. Precision of one laboratory machine

    Machine precision is an analytical validity issue.

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, Probability of detecting a true effect when it exists. Power is the probability a study will reject the null hypothesis when a real effect exists, and it rises with larger sample size and effect size.

Why is "Probability that null hypothesis is true" not the answer?

Null truth is not estimated by power.

Why is "Proportion of false-positive results" not the answer?

False positives relate to Type I error.

Why is "Precision of one laboratory machine" not the answer?

Machine precision is an analytical validity issue.

What concept does this question test?

It tests Biostatistics in PSM. The correct option holds because: Correct: power protects against Type II false-negative error.

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.