In a randomized controlled trial of a new oral hypoglycemic agent, 15% of patients allocated to the drug stopped taking it because of nausea, yet they remained under follow-up. For the primary efficacy analysis, the investigators should:

• A Exclude non-adherent patients and analyse only compliant participants
• B Reallocate non-adherent patients to the placebo arm
• C Analyse all patients in their originally assigned groups ✓
• D Analyse only patients who completed the full follow-up period

Explanation

Intention-to-treat analysis retains every randomized participant in the original allocation group regardless of adherence, preserving the prognostic balance created by randomization and estimating effectiveness under real-world conditions. Analysing only compliers, called per-protocol analysis, destroys randomization and invites attrition bias, since those tolerating the drug often differ systematically in prognosis from those who cannot.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.