Background: The placebo effect in randomized controlled trials (RCTs) for East Asian patients with ulcerative colitis (UC) has been poorly characterized. This systematic review and meta-analysis aimed to determine the placebo rates of clinical and endoscopic remission in East Asian patients with UC and to identify factors that influenced placebo outcomes.
Methods: A comprehensive search was performed to identify all eligible RCTs. The placebo rates of clinical and endoscopic remission were pooled by random effects. Univariate meta-regression was performed to evaluate the influence of different factors on these placebo rates.
Results: Fourteen induction and seven maintenance RCTs were included, comprising 1781 East Asian patients with UC. The pooled placebo rates of clinical and endoscopic remission for induction trials were 13% (95% confidence interval [CI] 10-16%) and 26% (95% CI 21-32%), respectively. Corresponding values for maintenance trials were 15% (95% CI 10-23%) and 24% (95% CI 19-29%). Heterogeneity existed among the studies. On univariate meta-regression, the route of drug administration, outcome definition, disease severity, disease duration, distal disease and concomitant corticosteroids influenced the outcomes of placebo arms.
Conclusions: The placebo rates of clinical and endoscopic remission in RCTs for East Asian patients with UC range from 13 to 26%, and are influenced by specific study characteristics. These results can inform the design and interpretation of future clinical trials in this region.
Keywords: East Asian; Meta-analysis; Placebo; Randomized controlled trial; Ulcerative colitis.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.