The Faroese IBD Study: Incidence of Inflammatory Bowel Diseases Across 54 Years of Population-based Data

Inflammatory bowel diseases [IBDs] include Crohn's disease [CD], ulcerative colitis [UC], and IBD unclassified [IBDU]. In 2010 and 2011, the ECCO-EpiCom study found the worldwide highest incidence of inflammatory bowel disease [IBD] in the Faroe Islands: 83 per 100 000 [European Standard Population, ESP]. The present study assessed the long-term time trends in IBD incidence in the Faroese population. In this population-based study, data were retrieved from the National Hospital of the Faroe Islands and included all incident cases of CD, UC, and IBDU diagnosed between July 1960 and July 2014. Patients of all ages were included and diagnoses were defined according to the Copenhagen Diagnostic Criteria. A total of 664 incident IBD patients were diagnosed: 113 with CD, 417 with UC, and 134 with IBDU. Of these, 51 [8%] were diagnosed with paediatric-onset IBD. Between 1960 and 1979, a total of 55 persons were diagnosed; 105 in 1980-89; 166 in 1990-99; 180 in 2000-09; and 158 in 2010-14. This represented an increase in the age-standardised IBD incidence rate from 7, 25, 40, and 42 to 74 per 100 000 [ESP]. For CD, the increase was from 1 to 10, for UC from 4 to 44, and for IBDU from 2 to 21 per 100 000 [ESP]. The high IBD incidence was found to be a relatively new phenomenon. The observed increase is unlikely to be an artefact resulting from, for instance, better registration. Our study indicated a real and increasing disease burden resulting from changing-so far unidentified-exposures.