Erre GL, Mavridis D, Woodman RJ, et al. - Although increasing over time, the placebo response for American College of Rheumatology 20 in psoriatic arthritis (PsA) randomized clinical trials (RCTs) was not related to the active treatment effect size.

• A total of 42 placebo-controlled RCTs in PsA (5,050 patients taking placebo) were analyzed to assess the placebo response rate in PsA RCTs, its contributing factors, and influence on the effect size of active treatments.

• Pooled placebo response rate of 20.3% was evident, with significant between-trial heterogeneity.

• For treatment vs placebo, pooled risk difference was 27%.

• For each five-year increase in publication year, a 15% increment in the odds of achieving the placebo response was observed in the multivariable meta-regression.

• Active treatment risk difference reduced for every 5-year increase in publication year but was not related to the placebo response.