Per-Protocol analyses produced larger treatment effect sizes than intention to treat: a meta-epidemiological study.

Objective: To undertake meta-analysis and compare treatment effects estimated by the intention-to-treat (ITT) method and per-protocol (PP) method in randomized controlled trials (RCTs). PP excludes trial participants who are non-adherent to trial protocol in terms of eligibility, interventions, or outcome assessment.

Study Design And Setting: Five high impact journals were searched for all RCTs published between July 2017 to June 2019.