Dual Therapy With Infliximab and Immunomodulator Reduces One-Year Rates of Hospitalization and Surgery Among Veterans With Inflammatory Bowel Disease

BACKGROUND & AIMS: Effectiveness of early treatment with biologics and immunomodulator therapy on healthcare utilization remains poorly defined. We assessed rates of hospitalization and surgery within 1 year after initiation of infliximab and/or immunomodulator therapy in a United States cohort of patients with inflammatory bowel disease. METHODS: We conducted a retrospective, observational cohort study of veterans with Crohn's disease or ulcerative colitis by using administrative data from 176 Department of Veteran Affairs facilities (October 1, 2001 through September 30, 2009). Inpatient, outpatient, and death records were linked longitudinally with prescription fill data. Each person-day of follow-up was assessed for treatment with infliximab, immunomodulators, both (dual therapy), or neither. We calculated drug exposure time and used Poisson and logistic regression analyses to assess outcomes. RESULTS: The cohort of 20,474 patients included 8042 patients with Crohn's disease and 12,432 with ulcerative colitis (93.9% male; 72.5% white; mean age, 60.9 +/- 14.5 years) prescribed infliximab (0.17%), immunomodulator (1.3%), or dual therapy (1.5%). Adjusted models revealed 50% relative reductions in hospitalization among patients who received 9.2 months of immunomodulator monotherapy, 8 months of infliximab, or 7.7 months of dual therapy. A 50% relative reduction in surgery was observed among patients receiving 7 months of infliximab or 5 months of dual therapy. Analysis of dose-response data revealed 73.1% and 92% reductions in risk of hospitalization and surgery, respectively, after 9 months of dual therapy. CONCLUSIONS: On the basis of a retrospective cohort study, dual therapy with infliximab and an immunomodulator for <8 months is associated with significant reductions in hospitalization and surgery within 1 year of the start of therapy. These findings indicate that patients with IBD are more likely to benefit if dual therapy is initiated earlier in their first year of therapy.