Incidence and clinical course of Crohn's disease during the first year - results from the IBD Cohort of the Uppsala Region (ICURE) of Sweden 2005-2009.

Background and Aims: As a part of the Swedish ICURE study where the epidemiological results of ulcerative colitis and microscopic colitis recently have been published, we hereby present the corresponding figures for Crohn's disease.
Methods: All patients diagnosed with Crohn's disease in Uppsala County (305,381 inhabitants) were prospectively registered during 2005-2006 and the same for all new patients with Crohn's disease in Uppsala Region (642,117 inhabitants) during 2007-2009.
Results: 264 patients with Crohn's disease were included. The mean annual incidence was 9.9/100,000/year (95% CI: 7.1-12.6). Incidence among children <17 years was 10.0/100,000/year (95% CI: 3.8-16.3). 51% of the patients had ileal involvement (L1: n=73, 28%. L2: n=129, 49%. L3: n=62, 23%, L4: n=47, 18%) and 23% had a stricturing or penetrating disease (B1: n=204, 77%. B2: n=34, 13%. B3: n=26, 10%. p: n=27, 10%). Intestinal resection rate during the first year was 12.5%. Patients with complicated disease had longer symptom duration before diagnosis compared to patients with non-complicated disease (median months 12.0, IQR: 3.0-24.0 vs 4.0, IQR: 2.0-12.0, p=0.0032). Patients 40 years or older had an increased risk for surgery (HR: 2.03, 95% CI: 1.01-4.08, p=0.0457).
Conclusions: The incidence of Crohn's disease in a region of Sweden is one of the highest reported in Europe. Long symptom duration precedes stricturing or penetrating behaviour. Old age is an independent risk factor for surgery.
(© 2013.)