Design and outcome measures of clinical trials for active ulcerative colitis: a scoping review based on databases

Abstract

Background Ulcerative colitis (UC) reduces the quality of life for patients and creates a significant economic burden on global healthcare systems. Although there have been advances in UC clinical trials recently, most existing reviews have primarily focused on pathogenesis or pharmacological treatments. This review analyzed the characteristics of current clinical trials for active ulcerative colitis and assessed research methods. This review focused on refining trial design and providing evidence-based methods for improving treatment outcomes and prognosis. Method This scoping review was conducted in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR). The study searched clinical trials registered in ClinicalTrials.gov and the Chinese Clinical Trial Registry (ChiCTR) from April 1, 2016, to April 1, 2026. In addition, the study searched PubMed for clinical trials published between April 1, 2016, and April 1, 2026. Data were charted and presented in tables. Result The study revealed a rapid increase in the number of clinical trials focusing on active ulcerative colitis since 2019. Biologics and small-molecule targeted drugs have become the core interventions, while traditional therapies constitute a smaller proportion of all treatments. However, these studies face limitations, such as small sample sizes, short follow-up periods, and an imbalance in outcome measures, which heavily rely on the Mayo score while underutilizing patient-reported outcomes and novel endoscopic scoring tools. Conclusion The number of clinical trials for active ulcerative colitis has increased, and intervention strategies have become more varied. However, there is significant variation in study populations, trial design, and the evaluation of their effectiveness. Future trials should prioritize large-scale, long-term studies with comprehensive and patient-centered outcome measures.