Objectives: A continuous increase in the incidence of inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC) has been suggested. Since Denmark provides excellent conditions for epidemiological research, we aimed to describe contemporary IBD incidence rates and patient characteristics in Copenhagen County and City.
Methods: All patients diagnosed with IBD during 2003-2005 were followed prospectively. Demographic and clinical characteristics, such as disease extent, extraintestinal manifestations, smoking habits, medical treatment, surgical interventions, cancer, and death, were registered.
Results: Five-hundred sixty-two patients were diagnosed with IBD, resulting in mean annual incidences of 8.6/10(5) for CD, 13.4/10(5) for UC, and 1.1/10(5) for IC. Time from onset to diagnosis was 8.3 months in CD and 4.5 months in UC patients. A family history of IBD, smoking, and extraintestinal manifestations was significantly more common in CD than in UC patients. Only 0.6% of UC patients had primary sclerosing cholangitis. In CD, old age at diagnosis was related to pure colonic disease, whereas children significantly more often had proximal and extensive involvement. Twelve percent of CD patients and 6% of UC patients underwent surgery during the year of diagnosis, significantly less than earlier reported.
Conclusions: The incidence of IBD in Copenhagen increased noticeably during the last decades. Time from onset of symptoms until diagnosis decreased markedly, extent of CD was related to age at diagnosis, and the risk of surgery was low in UC.