Background There is paucity of data on the outcomes of Acute Severe Ulcerative Colitis (ASUC) in older adults (≥60 years of age). The primary objective of our study was to assess steroid failure rate. The secondary outcomes assessed were need for colectomy during same admission, at 3 and 12months; mortality during admission for ASUC, at 3 months and 12months. Outcomes were compared with younger adults (< 60 years).

Methods All admissions for ASUC (fulfilling Truelove and Witts Criteria) between January 1, 2013 and July 31st, 2020 at two Australian tertiary IBD centres were retrospectively analysed. Review of electronic medical records was performed and clinical, endoscopic, laboratory data were collected. Non-parametric data were compared using Kruskal-Wallis test. Parametric data were compared using paired t-test.

Results 226 episodes of ASUC were analysed, 45 episodes were in patients who were ≥ 60 years of age at the time of ASUC event. Median Charlston comorbidity index was 3 (IQR: 2–4). In older adults, 19 (42.2%) failed intravenous steroid therapy and required rescue therapy. 2 (10.5%) episodes underwent direct colectomy, 17 episodes received medical rescue therapy (11 infliximab, 6 ciclosporin); 7 (63.6%) episodes received IFX 5mg/kg, 4 episodes (36.4%) received IFX 10mg/kg. 6 (13.3%) episodes had a colectomy during the admission for ASUC; 9 (20.9%) episodes had colectomy within 3 months and 9(20.9%) episodes underwent colectomy within 12 months. In patients < 60 years of age, steroid failure rate was 46.9% (85/181), 10.5% (19/181) underwent colectomy during the same admission, 17.6% (30/181) underwent colectomy by 3 months and 28.8% (42/181) had undergone colectomy at 12 months. In older adults, mortality during same admission occurred in 1 (2.2%) patient, 3-month mortality was 6.8% (3 patients) and 12-month mortality was 11.4% (5 patients). There was no mortality in patients < 60 years of age. Conclusion In older adults, steroid failure, the need for colectomy during the same admission and colectomy at 12 months is similar to a population <60 years of age. Mortality (at 3 and 12 months) is significantly higher.