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Statistics — SCE Medical Oncology MCQ

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EasyClinical Trials & StatisticsStatisticsSCE Medical Oncology

In a phase III oncology trial, the statistical plan specifies an intention-to-treat (ITT) analysis. 15% of patients in the experimental arm cross over to the control arm due to toxicity. How does ITT analysis handle these crossover patients?

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Correct answer: D — Patients are analysed in the arm to which they were originally randomised regardless of actual treatment received

Intention-to-treat analysis is the gold standard for RCT analysis. All randomised patients are analysed in their originally assigned group regardless of protocol adherence, crossover or dropout. This preserves the benefits of randomisation (balance of known and unknown confounders) and avoids selection bias. Per-protocol analysis (excluding non-adherent patients) can be performed as a sensitivity analysis but is not the primary analysis. ITT provides a conservative estimate of treatment effect in the presence of crossover.

Reference: JRCPTB Medical Oncology Curriculum; CONSORT Statement; ICH E9 Statistical Principles