Bias: 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 · Bias

Sample item

An observed exposure-outcome association is distorted by a third factor related to both; what is this source of bias called?

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

The answer and the reasoning

D. Distortion by a factor related to exposure and outcome

The defining Bias principle supports Distortion by a factor related to exposure and outcome; it directly accounts for the forensic observation, evidence requirement, or public-health measure in the question.

Option by option

  • A. Random assignment

    Random assignment does not establish the requested bias conclusion.

  • B. Loss of all participants

    Loss of all participants is not consistent with the finding or appropriate action described.

  • C. Perfect measurement

    Perfect measurement may be useful elsewhere but is not the best answer here.

  • D. Distortion by a factor related to exposure and outcome (correct)

    Correct. Distortion by a factor related to exposure and outcome best fits the important clue in this sample.

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 D, Distortion by a factor related to exposure and outcome. The defining Bias principle supports Distortion by a factor related to exposure and outcome; it directly accounts for the forensic observation, evidence requirement, or public-health measure in the question.

Why is "Random assignment" not the answer?

Random assignment does not establish the requested bias conclusion.

Why is "Loss of all participants" not the answer?

Loss of all participants is not consistent with the finding or appropriate action described.

Why is "Perfect measurement" not the answer?

Perfect measurement may be useful elsewhere but is not the best answer here.

What concept does this question test?

It tests Bias in PSM. The correct option holds because: Correct. Distortion by a factor related to exposure and outcome best fits the important clue in this sample.

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 Bias?

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.