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Number needed to treat — SCE Respiratory MCQ

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HardStatisticsNumber needed to treatSCE Respiratory

A trial of a new pulmonary rehabilitation programme reports mortality of 8% in the intervention arm and 12% in usual care after 1 year. The absolute risk reduction is 4%. What is the most likely interpretation?

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Correct answer: E — Twenty-five patients need treatment to prevent one death

The best answer is “Twenty-five patients need treatment to prevent one death”. The clinical pattern, physiology and imaging described are most consistent with Twenty-five patients need treatment to prevent one death. The competing diagnoses may share individual findings, but do not account for the complete combination in the stem. The remaining choices—“Four patients need treatment to prevent one death”, “The relative risk reduction is 4%, within a respiratory pathway”, “The intervention increases absolute risk, after safety review”, “The number needed to treat is 100, after specialist assessment”—are credible in related respiratory presentations, but each addresses a different diagnostic, staging or management decision and does not fit the decisive findings and pathway position in this stem.

Reference: British Thoracic Society respiratory guidance library: https://www.brit-thoracic.org.uk/quality-improvement/guidelines/