A population-based study of health-care resource use among infliximab users.

Objectives: We sought to describe the characteristics of health-care utilization (HCU) among patients with Crohn's disease using infliximab (IFX).

Methods: Using the University of Manitoba Inflammatory Bowel Disease Epidemiology Database (UMIBDED), we extracted all subjects with newly prescribed IFX, newly prescribed purine analogs (azathioprine, AZA) (without IFX), newly prescribed steroids (Ster) (without IFX or purine analogs) after 2001, and those not prescribed any of these drugs (ND). All of the subjects must have had HCU data available for 5 years before initial prescription and for 3 years afterward. We analyzed the number of physician visits, hospital visits, and surgeries.

Results: IBD-associated physician visits were consistently higher for IFX, both pre- and post-initial dosing, although overall physician visits were similar between IFX, AZA, and Ster. There was a steep rise in hospitalizations in the 6 months before initial prescription of IFX, AZA, or Ster, and hospitalizations were higher in the IFX cohort until 18-24 months after the first prescription, at which point levels fell to those evident 2-5 years before initiating IFX and to levels in the other drug groups. Likelihood of surgery post-dosing was greater in IFX than in AZA or ND for up to 36 months but was not different than Ster.

Conclusions: In a "step-up" approach to IFX use, it takes 2 years for the physician visits to reduce to 2-year pre-dosing rates and 18-24 months to reach hospitalization rates at 2 years pre-dosing and hospitalization rates of the AZA and Ster groups. Surgical rates to 3 years post-dosing were still higher than in AZA or ND groups.