The Inflammatory Bowel Disease Cohort of the Uppsala Region (ICURE) Epidemiology and Complications

Abstract: The overall aims of this thesis were to investigate the incidence of inflammatory bowel disease in the Uppsala Region of Sweden, to study the clinical course and the impact of the disease with regards to complications.Patients in Uppsala County were included in the study from the 1st of January 2005 and patients in Falun, Eskilstuna and Åland counties from the 1st of January 2007. The study was closed for all centres on the 31st of December 2009. Mean population in the study region was 305,381 in 2005–2006 and 642,117 in 2007–2009.The mean incidence for ulcerative colitis (UC) during the time period 2005-2009 was 20.0 /100,000/year (95% CI: 16.1-23.9) and for Crohn’s disease (CD) it was 9.9/100,000/year (95% CI: 7.1-12.6). The combined incidence for UC or CD in the area was thus 29.9/100,000/year (95% CI: 25.1-34.7).Half of the UC patients relapsed during the first year. Risk factors for relapse were female gender and young age. Colectomy during the first year was uncommon (2.5%). CD patients with complicated disease had longer symptom duration before diagnosis and less often diarrhoea and blood in stools compared to patients with non-complicated disease. The risk for surgery during the first year was 12%.The prevalence of anaemia at the time of diagnosis was 30% and after one year 18%. Anaemia was more common among newly diagnosed patients with CD compared with UC. 13% of the UC patients developed an acute severe episode. During the first 90 days 22% of these patients were subjected to colectomy. There was a significant difference between University and County hospitals in colectomy frequency (7.5% vs. 41%). The cumulative prevalence of treatment complications was 12% at the hospital with low colectomy rate versus 41% at the hospitals with high colectomy rate.In conclusion, the incidence of UC and CD in Sweden was high compared to international studies. Colectomy frequency for UC during the first year was low. Patients with complicated CD at the time of diagnosis had longer symptom duration and less alarming symptoms compared to uncomplicated disease. Anaemia was a common trait among patients with newly diagnosed IBD and more effort is needed to treat anaemia in these patients. Severe UC can be treated safely with prolonged medical therapy instead of colectomy.