title: Incidence, outcomes, and health services burden of very early onset inflammatory bowel disease.
abstract: OBJECTIVE
  The Paris pediatric modification of the Montreal classification defines very early onset inflammatory bowel disease (VEO-IBD) as a form of IBD distinct from that of older children. We compared the incidence and outcomes of VEO-IBD with those of IBD in older children.
  
  
  METHODS
  We performed a population-based retrospective cohort study of all children diagnosed with IBD in Ontario, Canada, from 1994 through 2009. Trends in standardized incidence were calculated using Poisson regression. We compared outpatient and emergency department visits, hospitalizations, and surgeries among children diagnosed with IBD when they were younger than age 6, ages 6-9.9, and older than age 10 years. Multivariable models were adjusted for income and stratified by sex.
  
  
  RESULTS
  The incidence of IBD increased from 9.4 per 100,000 children (95% confidence interval [CI], 8.2-10.8/100,000 children) in 1994 to 13.2 per 100,000 children (95% CI, 11.9-14.6/100,000 children) in 2009 (P < .0001). The incidence increased by 7.4% per year among children younger than 6 years old and 6-9.9 years old, and by 2.2% per year among children ≥10 years old. IBD-related outpatient visits were less frequent among children <6 years old than ≥10 years old (odds ratio for female patients, 0.67; 95% CI, 0.58-0.78; odds ratio for male patients, 0.86; 95% CI, 0.75-0.98). Hazard ratios [HRs] for hospitalization were lower for children <6 years old (female HR, 0.70; 95% CI, 0.56-0.87; male HR, 1.12; 95% CI, 0.94-1.33) than for older children. HRs for surgery among children <6 years old with Crohn's disease were 0.35 for female patients (95% CI, 0.16-0.78) and 0.59 for male patients (95% CI, 0.34-0.99). HRs for children <6 years old with ulcerative colitis were 0.88 for female patients (95% CI, 0.47-1.63) and 0.42 for male patients (95% CI, 0.21-0.85). There was no difference in hospitalization or surgery rates among children 6-9.9 years old vs those ≥10 years old.
  
  
  CONCLUSIONS
  Based on a retrospective cohort study, the incidence of VEO-IBD increased from 1994 through 2009. Children diagnosed with IBD before they were 6 years old used fewer health services and had lower rates of surgery than children diagnosed when they were 10 years or older.
authors.affiliation: Children's Hospital of Eastern Ontario Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, Children's Hospital of Eastern Ontario, Ottawa, Canada; Department of Pediatrics, University of Ottawa, Ottawa, Canada; Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Canada; Institute for Clinical Evaluative Sciences, Toronto, Canada. Electronic address: ebenchimol@cheo.on.ca.
authors.forename: Eric I
authors.initials: EI
authors.lastname: Benchimol
authors.affiliation: Children's Hospital of Eastern Ontario Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, Children's Hospital of Eastern Ontario, Ottawa, Canada; Department of Pediatrics, University of Ottawa, Ottawa, Canada.
authors.forename: David R
authors.initials: DR
authors.lastname: Mack
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Canada; Department of Medicine, University of Toronto, Toronto, Canada; Mount Sinai Centre for Inflammatory Bowel Disease, Toronto, Canada.
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Nguyen
authors.affiliation: Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital Boston, Boston, Massachusetts; Department of Medicine, Harvard University, Boston, Massachusetts.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Snapper
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Canada.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Canada.
authors.forename: Nassim
authors.initials: N
authors.lastname: Mojaverian
authors.affiliation: Children's Hospital of Eastern Ontario Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, Children's Hospital of Eastern Ontario, Ottawa, Canada; Institute for Clinical Evaluative Sciences, Toronto, Canada.
authors.forename: Pauline
authors.initials: P
authors.lastname: Quach
authors.affiliation: Department of Paediatrics, University of Toronto, Toronto, Canada; SickKids Inflammatory Bowel Disease Center, Division of Gastroenterology Hepatology and Nutrition, Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Aleixo M
authors.initials: AM
authors.lastname: Muise
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000553:Ambulatory Care / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D003082:Colectomy / Q000706:statistics & numerical data; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D003424:Crohn Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
keywords: Disease Progression; Epidemiology; Health Administrative Data; Pediatrics