title: Incidence and clinical presentation of IBD in children: comparison between prospective and retrospective data in a selected Norwegian population.
abstract: OBJECTIVE
  The results of recent research suggest that there is an increasing incidence of inflammatory bowel disease (IBD) among children. Newly diagnosed IBD was compared between two consecutive 6-year periods in the same catchment area of southeastern Norway.
  
  
  METHODS
  Children subjected to endoscopy from 1993 to 2004 were recorded retrospectively in the first 6-year period and prospectively for the subsequent period. The mean size of the child population under 16 years in the area was 70,500. The study reports on incidence numbers, age at diagnosis, disease distribution and clinical presentation at diagnosis.
  
  
  RESULTS
  There were 23 incident cases of IBD in the first period and 25 in the subsequent period. The rates of Crohn's disease (CD) for the two periods were, respectively, 1.95 and 3.64, and for ulcerative colitis (UC) 3.67 and 2.05/100,000 children/year. Total incidence rates of IBD for the two periods were 5.6 and 5.7, respectively, similar to the findings of the IBSEN study of 1990-94. The change in CD and UC rates from the first to the second period can be explained by better methods of diagnosis.
  
  
  CONCLUSIONS
  The total incidence of IBD was not changed between time periods, whereas a trend towards an increase in CD and a reduction in UC was recorded. The incidence rates are in accordance with previously reported national and international data from the past decade. The extent of disease in CD and UC may indicate a serious prognosis of IBD among children.
authors.affiliation: Department of Paediatrics, Akershus University Hospital, Norway. gori@perminow.no
authors.forename: Gøri
authors.initials: G
authors.lastname: Perminow
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Frigessi
authors.forename: Andreas
authors.initials: A
authors.lastname: Rydning
authors.forename: Britt
authors.initials: B
authors.lastname: Nakstad
authors.forename: Morten H
authors.initials: MH
authors.lastname: Vatn
mesh_terms: D002648:Child; D002675:Child, Preschool; D003093:Colitis, Ulcerative / Q000453:epidemiology; D003424:Crohn Disease / Q000453:epidemiology; D004724:Endoscopy; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D008297:Male; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D012189:Retrospective Studies