THU0416 Attrition Bias in Rheumatoid Arthritis Randomised Trials with Different Modified Intention-To-Treat Approaches: A Meta-Epidemiological Study

Background The intention-to-treat (ITT) principle preserves randomisation and prevents attrition bias [1]. Frequently data are missing [2] and the ITT analysis is executed by means of non-responder imputation (NRI) [3]. Deviations from ITT, referred to as modified ITT (mITT), excludes a restricted patient-group post-randomisation and is commonly used [4]. Objectives 1) To examine if mITT is associated with a different effect size compared to …