Placebo and nocebo responses in randomized controlled trials of Janus kinase inhibitor monotherapy for rheumatoid arthritis : A meta-analysis.

The frequency of placebo and nocebo responses was 33.0 and 54.1%, respectively, in JAK monotherapy trials for RA. The findings indicated that the strengths of placebo and nocebo responses are inversely proportional and that clinically significant differences were absent between AE, SAE, and dropout owing to AEs.