Increased Mortality and Healthcare Costs Upon Hospital Readmissions of Ulcerative Colitis Flares: A Large Population-Based Cohort Study

BACKGROUND: Ulcerative colitis (UC) flares often result in prolonged hospitalization and considerable mortality. Nevertheless, large-scale analyses evaluating the frequency and characteristics of hospital readmissions for UC remain limited. We aimed to examine these clinical outcomes in a nationwide cohort of patients hospitalized with UC. METHODS: We queried the 2017 Nationwide Readmission Database using ICD-10-CM codes to identify all adult patients admitted for UC. Outcomes including mortality, readmission rates, predictors of readmission and mortality, and healthcare usage were assessed. Multivariate analysis was used to adjust for potential confounders. RESULTS: From the 31,063 patients hospitalized for UC, 17.38% were readmitted within 30 days and 28.51% in 90 days. UC accounted for 28.17% and 29.82% of readmissions at 30 and 90 days, respectively. Compared to index admission, 30- and 90-day readmissions were characterized by significantly higher mortality (0.42% vs 1.99% and 1.65%, respectively), longer hospital stays (5.05 vs 6.62 and 6.04 days, respectively), and increased hospital cost ($49,999 vs $62,288 and $59,698, respectively) (all P < 0.01). Numerous factors, including chronic steroid use [hazard ratio (HR) 1.35] and opioid use (HR 1.6, were independently associated with increased 30-day readmission (P < 0.01). Numerous factors, including anxiety (HR 1.21) and venous thromboembolism (HR 5.39), were independently associated with increased 30-day mortality (P < 0.01). CONCLUSIONS: In a large cohort of patients hospitalized for UC, we found that readmission is associated with higher mortality and more lengthy/costly admissions. Additionally, we found independent associations for readmission and mortality that may help identify patients who can benefit from close postdischarge follow-up.