In a randomized trial of a statin versus placebo, some participants assigned to the statin stopped taking it, and some placebo participants started buying the drug over the counter. To preserve the validity of the original randomization, the primary analysis should be:

• A Per-protocol analysis
• B Intention-to-treat analysis ✓
• C As-treated analysis
• D Complete-case analysis excluding non-adherent participants

Explanation

Intention-to-treat analysis keeps every randomized participant in the originally assigned arm regardless of adherence or crossover, preserving the prognostic balance that randomization created and reflecting real-world effectiveness. Per-protocol and as-treated analyses reassign or restrict by actual drug received, destroying randomization and inviting attrition and crossover bias. Complete-case exclusion similarly discards non-random subsets of participants and biases the estimate.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.