Which analysis approach preserves randomization and estimates treatment effectiveness?

• A. Per-protocol analysis
• B. Subgroup analysis
• C. Intention-to-treat analysis
• D. As-treated analysis

Answer: (C)

Intention-to-treat analysis preserves randomization by analyzing participants in the groups to which they were randomized, regardless of whether they actually received or adhered to the assigned treatment. This approach provides an estimate of the real-world effectiveness of the treatment, including the impact of noncompliance, crossovers, and dropouts. Other methods—such as analyzing only those who followed the protocol, analyzing by the treatment actually received, or exploring effects within subgroups—do not maintain the initial random assignment and can introduce bias or yield estimates that do not reflect the overall treatment effect in practice.