Systematic Review and Meta-Analysis: Risk of Hospitalization in Patients with Ulcerative Colitis and Crohn's Disease in Population-Based Cohort Studies.

BACKGROUND AND AIMS Inflammatory bowel diseases (IBD) lead to high morbidity and unplanned healthcare utilization. We conducted a systematic review with meta-analysis to estimate the cumulative incidence of IBD-related (and all-cause) hospitalization in patients with ulcerative colitis (UC) and Crohn's disease (CD). METHODS Through a systematic review to September 3, 2019, we identified population-based inception cohort studies in patients with IBD that reported patient-level cumulative incidence of hospitalization at 1, 3 and 5 years after diagnosis. Hospitalization risk was pooled using random effects meta-analysis, and risk factors analyzed through mixed-effects meta-regression and qualitative synthesis. RESULTS In patients with UC (6 cohorts), 1-, 3- and 5-year risk of UC-related hospitalization was 10.4% (95% CI 8.2-13.2), 17.0% (95% CI 14.0-20.4) and 21.5% (95% CI 18.0-25.4), respectively, with considerable heterogeneity. In patients with CD (6 cohorts), 1-, 3- and 5-year risk of CD-related hospitalization was 29.3% (95% CI 20.0-40.8), 38.5% (95% CI 26.8-51.7) and 44.3% (95% CI 32.7-56.5), respectively, with considerable heterogeneity. On meta-regression, steady decline in risk of hospitalization was observed in patients diagnosed in a more contemporary era. Younger age at onset (both UC and CD), extensive colitis (UC), ileal-dominant CD, perianal CD and penetrating and/or stricturing behavior (CD) and early need for corticosteroids and immunosuppressive therapy (both UC and CD) were associated with increased risk of hospitalization. CONCLUSION Approximately one in five and one in two patients with UC and CD are hospitalized within 5 years of diagnosis, respectively. Population health management strategies are required to mitigate unplanned healthcare utilization.