A Prospective Population Based Cohort of Inflammatory Bowel Disease in the Biologics era - Disease Course and Predictors of Severity.

Background and AimWe have previously found high incidence of inflammatory bowel disease (IBD) in Australia. A population-based registry was established to assess disease severity, frequency of complications, and prognostic factors. MethodsIncident cases were prospectively identified over 4 years. Early disease severity was assessed according to need for hospitalization and resective surgery and medication use. ResultsWe report on the early outcomes (median 18 months, range 12-60 months) for 252 patients comprising 146 with Crohn's disease (CD), 96 with ulcerative colitis (UC), and 10 IBD undifferentiated. Eighty-seven percent of CD patients had inflammatory disease at diagnosis, and this reduced to 73% at 5 years (n=38). Immunomodulators were prescribed in 57% of CD patients and 19% with UC. A third of all CD patients were hospitalized, the majority (77%) in the first 12 months. Risk factors for hospitalization included penetrating, perianal, and ileocolonic disease (P<0.05). Twenty-four percent of UC patients were hospitalized, most within the first 12 months. Intestinal resection rates were 13% at 1 year in CD and 26% at 5 years. Risk factors include penetrating and stricturing disease (P<0.001) and ileal involvement (P<0.05). Colectomy rates in UC were 2% and 13% at 1 and 5 years. High C-reactive protein (CRP) at diagnosis was associated with colectomy. ConclusionsA high rate of inflammatory disease, frequent immunomodulator use in CD, and a low rate of surgery in both CD and UC were identified. In CD, ileal involvement and complex disease behavior are associated with a more severe disease course, while in UC a high CRP predicted this outcome.