The introduction of infliximab in Ontario, Canada, did not reduce hospitalizations or intestinal resections for inflammatory bowel disease (IBD), a recent study found.
Researchers used an interrupted time series design to study patients with Crohn's disease (CD) and ulcerative colitis (UC) in Ontario, Canada, between 1995 and 2012. They analyzed rates of IBD-related hospitalizations, intestinal resections, and public payer drug costs over 10 years among patients with CD and five years among patients with UC. The included number of patients varied by quarter, ranging from 13,603 to 37,210. Results were published by Gut on June 12.
Compared to the rates that would have been expected, the study found that the introduction of infliximab did not produce significant declines in rates of hospitalization (odds ratio [OR] at the last observation quarter, 1.06; 95% CI, 0.811 to 1.39) or intestinal resection (OR, 1.10; 95% CI, 0.810 to 1.50) related to CD or hospitalization (OR, 1.22; 95% CI, 1.07 to 1.39) or colectomy (OR, 0.933; 95% CI, 0.54 to 1.61) related to UC. The findings were similar in the subgroup of patients who took infliximab, except that hospitalizations declined significantly among UC patients following introduction of the drug (OR, 0.515; 95% CI, 0.342 to 0.777). Public payer drug costs went up substantially for patients with CD (OR, 2.98; 95% CI, 2.29 to 3.86) but did not significantly change among patients with UC (OR, 1.06; 95% CI, 0.955 to 1.18).
The study authors concluded that introduction of infliximab has not yielded anticipated reductions in the population rates of IBD-related hospitalizations or intestinal resections. “We hypothesise that misguided use and failure to optimise infliximab in many patients with CD, as well as underuse of this agent among patients with UC, may largely explain the underperformance of this treatment in the clinical practice setting,” the authors said. They speculated that infliximab may be overused in CD patients with symptomatic strictures and fistulas, but underused earlier in the disease course.
The study had a number of limitations. A major one was that it only included patients who received publicly funded infliximab. This is likely to be a more elderly and more treatment-refractory population than average, based on public funding rules in Ontario, the study authors explained. Given the unique aspects of the local health care funding, the results may not be generalizable and should be verified in other areas. Other outcomes, including the effects of infliximab on quality of life, function, and productivity, should also be studied.
“Ultimately, clinicians, policy makers and payers must understand how to optimise use and access of this proven therapy to maximally impact patient morbidity and thereby justify the escalating costs associated with this treatment,” they said.