Epidemiology: stratified randomisation: 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: stratified randomisation

Sample item

A multicentre trial randomises patients separately within each hospital, so every hospital has a similar number of patients in both arms. Which method is this?

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

The answer and the reasoning

B. Stratified randomisation

Stratified randomisation divides participants by an important prognostic factor, here the hospital, and randomises within each stratum. This ensures balance on that factor. Cluster randomisation allocates whole groups, not individuals.

Option by option

  • A. Simple randomisation

    Simple randomisation allocates everyone from a single list and may leave centres unbalanced.

  • B. Stratified randomisation (correct)

    Correct. Separate randomisation within each hospital is stratified randomisation.

  • C. Cluster randomisation

    Cluster randomisation allocates whole hospitals as units, but here patients are allocated individually.

  • D. Quasi-randomisation by alternate allocation

    Alternate allocation is not truly random and is open to selection bias.

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, Stratified randomisation. Stratified randomisation divides participants by an important prognostic factor, here the hospital, and randomises within each stratum.

Why is "Simple randomisation" not the answer?

Simple randomisation allocates everyone from a single list and may leave centres unbalanced.

Why is "Cluster randomisation" not the answer?

Cluster randomisation allocates whole hospitals as units, but here patients are allocated individually.

Why is "Quasi-randomisation by alternate allocation" not the answer?

Alternate allocation is not truly random and is open to selection bias.

What concept does this question test?

It tests Epidemiology: stratified randomisation in PSM. This ensures balance on that factor. Cluster randomisation allocates whole groups, not individuals.

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: stratified randomisation?

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.