P711 Outcomes of Outpatient Biologic Exposed Patients Hospitalized with Severe Ulcerative Colitis

Abstract

Abstract Background Up to 20% of patients with ulcerative colitis (UC) will require hospitalization for an acute severe flare. It is unclear whether outpatient exposure to biologics alters the outcomes of inpatient severe UC. We aimed to assess the outcomes of hospitalized severe UC patients exposed to biologics in the outpatient setting. Methods This was a multicenter, retrospective study of adult patients hospitalized with severe UC at University of Cambridge, Cambridge, St. Mark’s Hospital, London and Yale University, Connecticut (from 1/1/2012-11/1/2021). We included adult patients (age ≥ 18 years) who were hospitalized for a severe UC flare as determined by the treating clinician. The primary outcome was need for colectomy among outpatient biologic exposed vs biologic naïve patients. Secondary outcomes stratified by outpatient biologic exposure included length of hospitalization and need for rescue medical therapy. Results A total of 382 patients (53.2% male) with a median age of 35 years [interquartile range (IQR) 25-53] were reviewed. Outpatient biologic exposure was noted in 23.2% (n=86, 52 exposed to infliximab) while 76.8% (n=284) were naïve to biologics. Median disease duration was longer in the biologic exposed group at 6 years (IQR 2-11) compared to 2 years (IQR 1-8) in the biologic naïve group (p < 0.001). Biologic exposed group was more likely to have pancolitis (70.2% vs. 54.7%; p=0.04). The C-reactive protein (CRP) to albumin ratio was higher in the biologic naïve group was higher at 12.8 (IQR: 3.2-35) vs. 8 (IQR: 1-21.5) (p=0.004). The biologic exposed group was more likely to undergo colectomy at 25% (n=21) vs. 9.3% (n=26) in the biologic naïve group (p<0.001). The median hospital length of stay was 6 days (IQR: 4-9) in both groups (p=0.96). Need for rescue medical therapy 37.7% (n=107) in the biologic naïve group vs. 41.9% (n=36) in the biologic exposed group (p=0.49). Colectomy was associated with outpatient biologic exposure (44.7% vs. 19.9%, p=0.0002), Mayo UC endoscopic sub-score of 3 (81.6% vs. 55.1%, p=0.002), higher median CRP [70.6 (IQR:26.8-126.3) vs. 38.8 mg/dL (IQR: 9.7-94.7), p=0.04], lower median albumin [3 (IQR: 2.7-3.6) vs. 3.5 (IQR: 3-4) g/dL, p=0.0002], and female sex (61.2% vs. 44.8%, p=0.03). On multivariable analysis, only low albumin was independently associated with risk of colectomy (odds ratio: 3.31, 95% confidence interval 1.59-6.87, p=0.0005) Conclusion In our multicenter cohort, outpatient biologic exposure was associated with increased risk of colectomy among hospitalized patients with severe UC but on multivariable analysis only low albumin was independently associated with risk of colectomy. Further study of larger cohorts is warranted.