Infliximab in ulcerative colitis: the impact of preoperative treatment on rates of colectomy and prescribing practices in the province of British Columbia, Canada.

BACKGROUND: Approximately 20% of patients with ulcerative colitis will require surgical treatment. Recent data suggest that infliximab may reduce the need for surgery in patients with severe ulcerative colitis. However, it is unclear whether data from these small trials will translate to reduced colectomy rates in populations with ulcerative colitis.

OBJECTIVE: The purpose of this study was to determine the impact of infliximab on the rates of colectomy for ulcerative colitis and the prescribing practices for infliximab in British Columbia, Canada.

DESIGN: We retrospectively reviewed data from 4 province-wide population-based databases maintained by the British Columbia Ministry of Health, a central registry, a hospital separations file, a physician payment file, and a pharmaceutical file. Data were collected from April 1, 2001, to March 31, 2010.

SETTINGS: This investigation was conducted at the University of British Columbia.

PATIENTS: All patients aged 18 to 75 with ulcerative colitis were included and identified using a validated strategy with International Classification of Diseases 9/10 codes. Patients with severe ulcerative colitis were defined by treatment with a course of corticosteroids during the study period. Patients treated with infliximab were identified using the provincial pharmaceutical file.

MAIN OUTCOME MEASURES: The primary outcome was surgery determined by an International Classification of Diseases 9/10 code for partial or total colectomy.

RESULTS: Between 2001 and 2010, 7227 subjects were identified with ulcerative colitis. The number of subjects with severe ulcerative colitis was 2537. For general ulcerative colitis, rates of colectomy decreased from 9.97% to 8.88% in the preinfliximab era (2003-2004) and postinfliximab era (2008-2009; p = 0.03). For severe ulcerative colitis, there was no significant difference in colectomy rates (9.97% vs 11.14%; p = 0.18). The highest rate of infliximab prescription was found to be in the provincial health region that encompasses the tertiary academic centers of the province.

LIMITATIONS: Although the overall number of patients in this analysis is sizeable, the number of patients who were prescribed infliximab during the study period is relatively modest, which may have impacted trends.

CONCLUSIONS: In the severe ulcerative colitis population, there has been no change in the colectomy rate over time despite the introduction of infliximab.