Clinical Epidemiology (Nov 2021)

Incidence of Inflammatory Bowel Disease in South Asian and Chinese People: A Population-Based Cohort Study from Ontario, Canada

  • Dhaliwal J,
  • Tuna M,
  • Shah BR,
  • Murthy S,
  • Herrett E,
  • Griffiths AM,
  • Benchimol EI

Journal volume & issue
Vol. Volume 13
pp. 1109 – 1118

Abstract

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Jasbir Dhaliwal,1– 6 Meltem Tuna,1 Baiju R Shah,1,7,8 Sanjay Murthy,1,9,10 Emily Herrett,4 Anne M Griffiths,2,3 Eric I Benchimol1– 3,8 1ICES, Toronto, ON, Canada; 2SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, ON, Canada; 3Department of Paediatrics, University of Toronto, Toronto, ON, Canada; 4London School of Hygiene and Tropical Medicine, London, UK; 5Cincinnati Children’s Hospital Medical Center, Division of Gastroenterology, Hepatology and Nutrition, Cincinnati, OH, USA; 6Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA; 7Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 8Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada; 9The Ottawa Hospital IBD Centre, The Ottawa Hospital and Ottawa Hospital Research Institute, Ottawa, ON, Canada; 10Department of Medicine and School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, CanadaCorrespondence: Jasbir DhaliwalPediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Division of Gastroenterology, Hepatology and Nutrition, Secondary Appointments in Division of Biomedical Informatics and James M Anderson Center for Health Systems Excellence, 3333 Burnet Avenue, Cincinnati, OH, 45229, USATel +15133789468Email [email protected]: Inflammatory bowel disease (IBD) is now a global disease with incidence increasing throughout Asia.Aim: To determine the incidence of IBD among South Asians and Chinese people residing in Ontario, Canada’s most populous province.Methods: All incident cases of IBD in children (1994– 2015) and adults (1999– 2015) were identified from population-based health administrative data. We classified South Asian and Chinese ethnicity using immigration records and surnames. We determined standardized incidence of IBD and adjusted incidence rate ratio (aIRR) in South Asians and Chinese compared to the general population.Results: Among 16,230,638 people living in Ontario, standardized incidence of IBD per 100,000 person-years was 24.7 (95% CI 24.4– 25.0), compared with 14.6 (95% CI 13.7– 15.5) in 982,472 South Asians and with 5.4 (95% CI 4.8– 5.9) in 764,397 Chinese. The risk of IBD in South Asians was comparable to the general population after adjusting for immigrant status and confounders (aIRR 1.03, 95% CI 0.96– 1.10). South Asians had a lower risk of Crohn’s disease (CD) (aIRR 0.66, 95% CI 0.60– 0.77), but a higher risk of ulcerative colitis (UC) (aIRR 1.47, 95% CI 1.34– 1.61). Chinese people had much lower rates of IBD (aIRR 0.24, 95% CI 0.20– 0.28), CD (aIRR 0.21, 95% CI 0.17– 0.26), and UC (aIRR 0.28, 95% CI 0.23– 0.25).Conclusion: Canadians of South Asian ethnicity had a similarly high risk of developing IBD compared to other Canadians, and a higher risk of developing UC, a finding distinct from the Chinese population. Our findings indicate the importance of genetic and environmental risk factors in people of Asian origin who live in the Western world.Keywords: inflammatory bowel disease, ulcerative colitis, Crohn’s disease, incidence, ethnicity, epidemiology, South Asian, Chinese

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