Upadacitinib Reduces Rates of Hospitalization in Ulcerative Colitis: A Large-Scale Nationwide Cohort Study

Background/Objectives: Upadacitinib is recommended for moderate-to-severe ulcerative colitis (UC); however, data regarding its effectiveness and long-term outcomes in large patient populations remain limited. In this nationwide, hospital-based cohort study, we investigated the effectiveness and long-term outcomes of upadacitinib in patients with UC. Methods: This study included 2694 patients with UC who received upadacitinib. The primary outcome was the comparison of hospitalization rates during the 1-year periods before and after the initiation of upadacitinib. Additionally, the cumulative hospitalization rate up to 2 years post-initiation was evaluated. Results: Of 2694 patients who were initiated on upadacitinib, the median age was 45 (31–57) years, and 60.5% were male. In the year preceding upadacitinib initiation, 29.3% of the patients were hospitalized due to UC. In the 1 year following upadacitinib initiation, the hospitalization rate significantly decreased to 9.6% (p < 0.001). Furthermore, the cumulative hospitalization rate up to 2 years was 12.6%. Among patients with a prior history of hospitalization, the hospitalization rate in the 1 year after upadacitinib initiation decreased from 100% to 16.8%. A significant improvement in the hospitalization rate was observed in both advanced therapy-naïve and -exposed patients. After adjusting for age, sex, steroid use, and history of advanced therapy, the hazard ratio (95% confidence interval) for hospitalization associated with upadacitinib initiation was 0.39 (0.33–0.46, p < 0.001). Conclusions: The initiation of upadacitinib was associated with significantly lower hospitalization rates, and this association was maintained for up to two years. These findings support upadacitinib as an effective and viable treatment option for patients with moderate-to-severe UC.