First prospective, population-based inflammatory bowel disease incidence study in mainland of China: the emergence of "western" disease.

BACKGROUND

Previously a disease of the West and rarely seen in China, inflammatory bowel disease (IBD) is now increasing in incidence in China. However, its true incidence is unknown. The incidence of IBD in Wuhan, a major city in central China, was investigated using population-based methods.

METHODS

A prospective, population-based IBD incidence study was conducted between January 1, 2010, and December 31, 2010. New IBD cases were identified by gastroenterologists and from hospital case records in 17 central hospitals covering the health care service of central Wuhan. Cases were confirmed by follow-up and assessed by a specialist IBD group every 3 months. The population at risk was 6,085,556.

RESULTS

Overall, 131 new cases of IBD were identified during the 1-year period, including 97 cases of ulcerative colitis (UC) and 34 cases of Crohn's disease (CD). The age-adjusted incidence for all IBD, UC, and CD were 1.96 per 100,000 (95% confidence interval [CI], 1.62-2.30 per 100,000), 1.45 (95% CI, 1.16-1.75), and 0.51 (95% CI, 0.33-0.68), respectively. CD affected the small bowel only in 15%, colon only in 24%, and ileocolonic in 61%. CD often presented with complicated phenotype: inflammatory (44%), stricturing (29%), and penetrating (24%). Among patients with UC, complications included proctitis (34.5%), left-sided colitis (44.6%), and extensive colitis (19.5%).

CONCLUSIONS

There is a substantial incidence of IBD in China. Although still lower than in the West, the emergence of IBD will necessitate specific health care planning and education and offers the possibility of identifying causative factors in a population with a rapidly increasing incidence.