Infliximab induction regimens in steroid‐refractory acute severe colitis: a multicentre retrospective cohort study with propensity score analysis

Background: Accelerated induction regimens of infliximab have been proposed to improve response rates in patients with steroid refractory acute severe colitis. Aims: We aimed to determine differences in outcome for acute severe ulcerative colitis between accelerated and standard-dose infliximab. Methods: We collected data on hospitalised patients receiving differing regimens of rescue therapy for steroid refractory Acute Severe Ulcerative Colitis. Our primary outcome was 30-day colectomy rate. Secondary outcomes were colectomy within index admission, 90 days and 12 months. We used propensity score analysis with optimal calliper matching using a priori defined high-risk covariates to reduce potential provider selection bias. Results: We included 131 patients receiving infliximab rescue therapy; 102 patients received standard induction and 29 received accelerated induction. In the unmatched cohort, there was no difference by type of induction in 30-day colectomy rates (18% vs. 20%, p=0.45), colectomy during index admission (13% vs. 20%, p = 0.26) or overall colectomy (20% vs. 24%, p= 0.38). In the propensity score-matched cohort of 52 patients, 30-day colectomy (57% vs. 27%, p = 0.048) and index admission colectomy (53% vs. 23%,p =0.045) rates were higher in those receiving standard induction compared to accelerated induction but there was no difference in overall colectomy rates between the 2 groups (57% vs. 31%, p =0.09). There was no significant difference in length of stay or in complication and infection rates. Conclusion: In a propensity score matched cohort, steroid refractory Acute Severe Ulcerative Colitis patients, short-term, but not long-term, colectomy rates appear to be lower in those receiving accelerated induction regimen.