Gastroenterology

Gastroenterology

Volume 145, Issue 1, July 2013, Pages 158-165.e2
Gastroenterology

Original Research
Full Report: Clinical—Alimentary Tract
Incidence and Phenotype of Inflammatory Bowel Disease Based on Results From the Asia-Pacific Crohn's and Colitis Epidemiology Study

https://doi.org/10.1053/j.gastro.2013.04.007Get rights and content

Background & Aims

Inflammatory bowel diseases (IBD) are becoming more common in Asia, but epidemiologic data are lacking. The Asia-Pacific Crohn’s and Colitis Epidemiology Study aimed to determine the incidence and phenotype of IBD in 8 countries across Asia and in Australia.

Methods

We performed a prospective, population-based study of IBD incidence in predefined catchment areas, collecting data for 1 year, starting on April 1, 2011. New cases were ascertained from multiple overlapping sources and entered into a Web-based database. Cases were confirmed using standard criteria. Local endoscopy, pathology, and pharmacy records were searched to ensure completeness of case capture.

Results

We identified 419 new cases of IBD (232 of ulcerative colitis [UC], 166 of Crohn’s disease [CD], and 21 IBD-undetermined). The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia (95% confidence interval: 1.25−1.51; 0.76 for UC, 0.54 for CD, and 0.07 for IBD-undetermined) and 23.67 in Australia (95% confidence interval: 18.46−29.85; 7.33 for UC, 14.00 for CD, and 2.33 for IBD-undetermined). China had the highest incidence of IBD in Asia (3.44 per 100,000 individuals). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Median time from symptom onset to diagnosis was 5.5 months (interquartile range, 1.4−15 months). Complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P = .001), and a family history of IBD was less common in Asia (3% vs 17%; P < .001).

Conclusions

We performed a large-scale population-based study and found that although the incidence of IBD varies throughout Asia, it is still lower than in the West. IBD can be as severe or more severe in Asia than in the West. The emergence of IBD in Asia will result in the need for specific health care resources, and offers a unique opportunity to study etiologic factors in developing nations.

Section snippets

Study Setting and Study Population

The Asia-Pacific Crohn's and Colitis Epidemiology (ACCESS) study was conducted in 21 centers in 12 cities in 9 countries (considering Hong Kong and Macau separately from mainland China) across Asia-Pacific. The countries involved were Australia, mainland China, Hong Kong, Indonesia, Macau, Malaysia, Singapore, Sri Lanka, and Thailand. Study population and centers were selected based on the following predefined criteria: well-defined boundaries and relatively geographically isolated; stable

Incidence of IBD

During the 1-year period, 419 new IBD cases were identified, including 232 (55.4%) ulcerative colitis (UC), 166 (39.6%) Crohn’s disease (CD), and 21 (5.0%) IBD-undetermined (IBD-U).

The majority of patients were medically referred (65%−87%), and the remaining were self-referred (0−2%), or invited (11%−34%) (Supplementary Table 1). The crude annual overall incidence per 100,000 of IBD was 1.37 (95% CI: 1.25−1.51; UC was 0.76, CD was 0.54, and IBD-U was 0.07) in Asia and 23.67 (95% CI:

Discussion

To the best of our knowledge, this is the first comparative epidemiologic study of IBD across Asia and the Pacific. Although the incidence in Asia is lower than in the West, these figures still represent a clinically important disease burden, considering that 20 years ago IBD was rare or almost nonexistent in Asia. As development and globalization in Asia continue, the incidence of IBD is likely to increase. Epidemiological studies in Asian countries, with the exception of Japan, which has a

Acknowledgments

The authors are grateful to Y. K. Tse for statistical input, Sunny Wong for illustration, and Honson Lam for input on database amendment and updates. The authors are thankful to Drs. K. C. D. Mettananda, Nilesh Fernandopulle, Shaman Rajindrajith, P. R. Waraketiya, S. K. Weerasinghe, A. Ranaweera, Prof. S. JdeS Hewavisenthi, Prof. A. P. de Silva (Sri Lanka), Nazri Mustaffa (Sydney), Fan Siok Chiang (Singapore), Jessica Leung and Rosita Chan (Hong Kong), Zhang Jun Wen (Macau), and all other

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    Conflicts of interest The authors disclose no conflicts.

    Funding Unrestricted educational grants from Ferring pharmaceuticals, Hong Kong, and Direct Grant Faculty of Medicine Chinese University of Hong Kong were used to support the database setup and maintenance of this study. The study sponsors have no contribution in the study design, analysis, interpretation of data, and publication.

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