OBJECTIVES: In this population-based 7-year follow-up of incident patients with ulcerative colitis (UC) or Crohn's disease (CD), we aimed to describe disease progression and surgery rates in an era influenced by the increased use of immunosuppressants and the introduction of biological therapy.

METHODS: From 1 January 2003 to 31 December 2004, all incident cases (562) of patients diagnosed with UC, CD, or inflammatory bowel disease unclassified in a well-defined Copenhagen area were registered. Medical records were reviewed from 1 November 2011 to 30 November 2012, and clinical data were registered. Clinical data on surgery, cancer, and death were cross-checked with register data from national health administrative databases in order to include missed data.

RESULTS: In total, 513 patients (213 CD and 300 UC) entered the follow-up study. Twenty-six patients changed diagnosis during the follow-up. Changes in disease localization and behavior in CD according to the Vienna classification were observed in 23.9% and 15.0% of the patients, respectively, during follow-up. In total, 28.3% of the 300 UC patients had disease progression during the follow-up. The overall use of systemic steroids, immunomodulators, and anti-tumor necrosis factor agents in CD was 86.4%, 64.3%, and 23.5%, respectively. The rate of first-time intestinal resection in CD was 29.1% (n=62), and the 7-year cumulative risk was 28.5%. The cumulative risk of colectomy in UC was 12.5% at 7 years.

CONCLUSIONS: UC and CD are dynamic diseases that progress in extent and behavior over time. The resection rate in CD and the colectomy rate in UC are still relatively high, although the rates seem to have decreased compared with historic data, which could be due to an increase in the use of immunomodulating therapy.