title: Younger age at diagnosis is associated with panenteric, but not more aggressive, Crohn's disease.
abstract: OBJECTIVE
  Crohn's disease (CD) diagnosed in pediatric patients has been reported to have a more aggressive phenotype and course, with a greater prevalence of upper gastrointestinal involvement, than in adults. However, studies have not accounted for differences in diagnostic tests. We aimed to discern whether, in fact, CD diagnosed in childhood has a different outcome than CD diagnosed in adults.
  
  
  METHODS
  We performed comprehensive medical chart reviews of 571 patients with CD (451 with complete data) who were followed in a single referral inflammatory bowel disease clinic in Winnipeg, Canada, from 1993-2012. For specific time intervals, we determined types and numbers of imaging studies performed and parameters of disease phenotype, including age at diagnosis according to the Montreal classification (A1 diagnosed <17 years of age, A2 diagnosed 17-40 years, and A3 diagnosed >40 years).
  
  
  RESULTS
  Within 1 year of diagnosis, a higher proportion of A1 patients had upper gastrointestinal involvement and ileocolonic (L3) disease than A2 or A3 patients. These differences could be partly accounted for by the diagnostic tests performed during this time period. Although A1 patients underwent more extensive imaging studies, they had a lower prevalence of complicated disease, particularly compared with A3 patients. After a median follow-up period of 11.1 years, complicated disease behavior (B2 [structuring] or B3 [penetrating]) was similar among the 3 groups. Nonetheless, at the end of the study period, rates of inflammatory bowel disease-related abdominal surgery were significantly lower for A1 than A2 patients (odds ratio, 0.63; 95% confidence interval, 0.41-0.98) but not for A3 patients (odds ratio, 0.71; 95% confidence interval, 0.40-1.27).
  
  
  CONCLUSIONS
  On the basis of a database analysis of different age groups of patients with CD, studies of disease phenotypes among different cohorts should account for different patterns of diagnostic imaging evaluation. Our data show that although children are at increased risk of panenteric disease, they are not more likely to have more complicated disease or undergo surgery than adults.
authors.affiliation: IBD Unit, Department of Gastroenterology and Liver Diseases, Hadassah-Hebrew University Hospital, Jerusalem, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Israeli
authors.affiliation: University of Manitoba IBD Clinical and Research Centre, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: John D
authors.initials: JD
authors.lastname: Ryan
authors.affiliation: University of Manitoba IBD Clinical and Research Centre, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Leigh-Anne
authors.initials: LA
authors.lastname: Shafer
authors.affiliation: University of Manitoba IBD Clinical and Research Centre, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address: charles.bernstein@med.umanitoba.ca.
authors.forename: Charles N
authors.initials: CN
authors.lastname: Bernstein
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
keywords: CD; CI; CT; Crohn's disease; EGD; Endoscopy; IBD; Inflammatory Bowel Disease; MRI; Montreal Classification; OR; Progression; Radiology; SBBS; UGI; computed tomography; confidence interval; esophagogastroduodenoscopy; inflammatory bowel disease; magnetic resonance imaging; odds ratio; small bowel barium series; upper gastrointestinal