Intention-to-Treat Analysis
A statistical method that analyses all participants based on their original group assignment, regardless of whether they completed treatment. ITT analysis preserves randomisation integrity and provides a conservative, real-world estimate of treatment effect. It is the standard primary analysis for regulatory submissions.
Technical Context
ITT analysis follows the principle that the groups should remain comparable as randomised. Including all randomised patients (even dropouts) prevents: selection bias (analysing only 'good' patients), attrition bias (differential dropout between groups), and inflated effect estimates. Handling missing data in ITT: multiple imputation, mixed-effects models for repeated measures (MMRM), or conservative assumptions (e.g. baseline observation carried forward for primary outcomes). For weight management trials, a key ITT distinction is the treatment policy estimand (what is the effect of being assigned to treatment, including those who discontinue?) vs the trial product estimand (what is the effect in patients who continue treatment?). Both are reported but the treatment policy estimand is the primary regulatory analysis.