Epidemiology: interviewer 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 · Epidemiology: interviewer bias

Sample item

In a case-control study of oral cancer, an interviewer who knows which participants are cases probes cases more persistently about tobacco chewing than controls. Which bias does this introduce?

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

The answer and the reasoning

A. Interviewer bias

Interviewer bias arises when the person collecting data elicits information differently from cases and controls because of knowledge of their status. Recall bias arises from the participants' own memory, not the interviewer's behaviour. Blinding the interviewer and using structured questionnaires reduce it.

Option by option

  • A. Interviewer bias (correct)

    Correct. Differential probing by an interviewer who knows case status is interviewer bias.

  • B. Lead-time bias

    Lead-time bias is a screening artefact that lengthens apparent survival.

  • C. Recall bias

    Recall bias comes from participants remembering exposures differently, not from how the interviewer asks.

  • D. Berkson's bias

    Berkson's bias comes from hospital-based selection of cases and controls.

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 A, Interviewer bias. Interviewer bias arises when the person collecting data elicits information differently from cases and controls because of knowledge of their status.

Why is "Lead-time bias" not the answer?

Lead-time bias is a screening artefact that lengthens apparent survival.

Why is "Recall bias" not the answer?

Recall bias comes from participants remembering exposures differently, not from how the interviewer asks.

Why is "Berkson's bias" not the answer?

Berkson's bias comes from hospital-based selection of cases and controls.

What concept does this question test?

It tests Epidemiology: interviewer bias in PSM. Recall bias arises from the participants' own memory, not the interviewer's behaviour. Blinding the interviewer and using structured questionnaires reduce it.

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 Epidemiology: interviewer 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.