Placebo-controlled trials of procedural interventions showed reduced effectiveness compared to unblinded trials for exercise-related outcomes, quality of life, and health professional-assessed endpoints. The placebo effect explained a substantial portion of the observed effect size differences. No significant differences were found for patient-reported outcomes, blood pressure, mortality, pain, or recurrent bleeding events. The study emphasizes the importance of including a placebo arm in procedural intervention trials.
Journal Article by Rajkumar CA, Thomas KE (…) Al-Lamee RK et 12 al. in JAMA Surg