Increasing incidence of paediatric inflammatory bowel disease in Ontario, Canada: evidence from health administrative data
- E I Benchimol1,2,3,
- A Guttmann1,3,4,
- A M Griffiths2,4,
- L Rabeneck1,3,5,
- D R Mack6,
- H Brill7,
- J Howard8,
- J Guan1,
- T To1,3,9
- 1The Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada
- 2Division of Gastroenterology, Hepatology & Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada
- 3Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
- 4Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
- 5Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- 6Division of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Eastern Ontario, Ottawa, Ontario, Canada
- 7Division of Gastroenterology and Nutrition, McMaster Children’s Hospital, Hamilton, Ontario, Canada
- 8Department of Paediatrics, London Health Sciences Centre, London, Ontario, Canada
- 9Childhealth Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
- Correspondence to Dr E Benchimol, Division of Gastroenterology, Hepatology & Nutrition, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada, M4S 1C5;
- Revised 8 July 2009
- Accepted 21 July 2009
- Published Online First 2 August 2009
Objective: Health administrative databases can be used to track chronic diseases. The aim of this study was to validate a case ascertainment definition of paediatric-onset inflammatory bowel disease (IBD) using administrative data and describe its epidemiology in Ontario, Canada.
Methods: A population-based clinical database of patients with IBD aged <15 years was used to define cases, and patient information was linked to health administrative data to compare the accuracy of various patterns of healthcare use. The most accurate algorithm was validated with chart data of children aged <18 years from 12 medical practices. Administrative data from the period 1991–2008 were used to describe the incidence and prevalence of IBD in Ontario children. Changes in incidence were tested using Poisson regression.
Results: Accurate identification of children with IBD required four physician contacts or two hospitalisations (with International Classification of Disease (ICD) codes for IBD) within 3 years if they underwent colonoscopy and seven contacts or three hospitalisations within 3 years in those without colonoscopy (children <12 years old, sensitivity 90.5%, specificity >99.9%; children <15 years old, sensitivity 89.6%, specificity >99.9%; children <18 years old, sensitivity 91.1%, specificity 99.5%). Age- and sex-standardised prevalence per 100 000 population of paediatric IBD has increased from 42.1 (in 1994) to 56.3 (in 2005). Incidence per 100 000 has increased from 9.5 (in 1994) to 11.4 (in 2005). Statistically significant increases in incidence were noted in 0–4 year olds (5.0%/year, p = 0.03) and 5–9 year olds (7.6%/year, p<0.0001), but not in 10–14 or 15–17 year olds.
Conclusion: Ontario has one of the highest rates of childhood-onset IBD in the world, and there is an accelerated increase in incidence in younger children.
Funding This research was funded by a Clinical Research Award from the American College of Gastroenterology and was made possible with the support of the Institute for Clinical Evaluative Sciences which receives funding from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The results and conclusions are those of the authors; no official endorsement by the Ontario MOHLTC should be inferred. EB is a Canadian Institutes of Health Research (CIHR) training fellow in the Canadian Child Health Clinician Scientist Program, in partnership with the SickKids Foundation and the Child & Family Research Institute of British Columbia, and was also supported by fellowships from the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition-Children’s Digestive Health and Nutrition Foundation, and the Clinician Scientist Training Program of the Research Institute of the Hospital for Sick Children. AG was supported by a CIHR New Investigator Award.
Competing interests None.
Provenance and Peer review Not commissioned; externally peer reviewed.
Ethics approval This study was approved by the research ethics boards of the Hospital for Sick Children (SickKids), Sunnybrook Health Sciences Centre and all institutions involved in the validation study.