S1917 Incidence and Predictors of Hospital Readmission for Ulcerative Colitis

Introduction: Over 3 million individuals in the United States live with inflammatory bowel disease, with approximately half affected by ulcerative colitis (UC). About 50% of UC patients require at least one disease-related hospitalization, and up to 20% may be readmitted within 30 days. Existing U.S.-based studies are limited by small sample sizes, poor generalizability, and lack of granular data on index hospitalizations and follow-up care. Methods: We conducted a retrospective cohort study of adults hospitalized with a primary diagnosis of UC between January 2010 and September 2023 within a large integrated healthcare system serving over 4.5 million individuals. We evaluated the incidence of all-cause 30-day readmissions and identified predictors by analyzing patient characteristics, hospitalization details, post-discharge care, and maintenance UC therapy changes. Results: The cohort included 942 patients (mean age 46.2 years; 50.5% women; 57% White). Of these, 151 patients (16%) were readmitted within 30 days. Univariate analysis showed readmitted patients had lower albumin levels at index admission (2.7 vs 2.9 g/dL, P < 0.05) and longer length of stay (6.8 vs 5.5 days, P < 0.05). Post-discharge, readmitted patients were less likely to follow up within 30 days with gastroenterology (26% vs 70%, P < 0.001) or a primary care provider (39% vs 77%, P < 0.001). They were also less likely to have a major change in UC therapy, defined as initiation of a new treatment (10% vs 32%). Multivariate analysis, adjusted for demographics, comorbidities, medications, and follow-up, found that malnutrition (OR 1.9, 95% CI 1.2–3.2, P = 0.01), lack of GI follow-up (odds ratio [OR] 5.3, 95% CI 3.4–8.3, P < 0.01), and lack of PCP follow-up (OR 4.2, 95% CI 2.8–6.5, P < 0.01) were significantly associated with 30-day readmission. A major change in UC therapy was protective (OR 3.1, 95% CI 1.6–6.1, P = 0.001). Conclusion: Patients hospitalized for UC face high 30-day readmission rates. While clinical factors such as malnutrition and longer index hospitalization are predictive, timely post-discharge interventions—including GI and PCP follow-up and UC treatment modification—may significantly reduce readmissions.