Decreasing trends in hospitalizations during anti-TNF therapy are associated with time to anti-TNF therapy: Results from two referral centres

Background: Hospitalization is an important outcome measure and a major driver of costs in patients with inflammatory bowel disease. We analysed medical and surgical hospitalization rates and predictors of hospitalization before and during anti-TNF therapy. Methods: Data from 194 consecutive patients were analysed retrospectively (males, 45.4%, median age at diagnosis, 24.0 years, infliximab/adalimumab: 144/50) in whom anti-TNF therapy was started after January 1, 2008. Total follow-up was 1874 patient-years and 474 patient-years with anti-TNF exposure. Results: Hospitalization rates hospitalization decreased only in Crohn's disease (odds ratio: 0.59, 95% confidence interval: 0.51-0.70, median 2-years' anti-TNF exposure) with a same trend for surgical interventions (. p=. 0.07), but not in ulcerative colitis. Need for hospitalization decreased in Crohn's disease with early (within 3-years from diagnosis, p=. 0.016 by McNemar test), but not late anti-TNF exposure. At logistic regression analysis complicated disease behaviour (. p=. 0.03), concomitant azathioprine (. p=. 0.02) use, but not anti-TNF type, gender, perianal disease or previous surgeries were associated with the risk of hospitalization during anti-TNF therapy. Conclusion: Hospitalization rate decreased significantly in patients with Crohn's disease but not ulcerative colitis after the introduction of anti-TNF therapy and was associated with time to therapy. Complicated disease phenotype and concomitant azathioprine use were additional factors defining the risk of hospitalization.