Assessment of Placebo Response in Objective and Subjective Outcome Measures in Rheumatoid Arthritis Clinical Trials

Key Points Question Are subjective patient-reported outcomes vs objective biomarkers associated with higher placebo responses in clinical trials? Findings In this cross-sectional study examining the placebo arms of 5 randomized clinical trials of rheumatoid arthritis including 788 patients, objective markers of inflammation and subjective pain ratings improved in a comparable clinically meaningful magnitude. Baseline values were associated with placebo response, suggesting that regression to the mean might dominate response to randomized placebo treatment. Meaning The findings of this study suggest that investigators may need to improve their understanding of natural history and baseline levels of outcomes because these factors can be important contributors to the response in placebo arms.