Racial/ethnic and regional differences in the prevalence of inflammatory bowel disease in the United States

Background: The magnitude of racial/ethnic and regional differences in the prevalence of inflammatory bowel disease (IBD) in the United States remains largely unknown. Aims: To estimate differences in the prevalence of IBD by race/ethnicity and region. Methods: The Medical Expenditure Panel Survey, a nationally representative survey of US households and medical conditions, was used. A multivariate logistic model was used in statistical analysis. Results: Among 202,468 individuals surveyed during 1996-2007, 316 were diagnosed with IBD (26 Blacks, 21 Hispanics, and 5 Asians). The prevalence of IBD was higher in Whites [Crohn's disease: 154; ulcerative colitis (UC): 89] than Blacks (Crohn's disease: 68; UC: 25), Hispanics (Crohn's disease: 15; UC: 35), and Asians (Crohn's: 45; UC: 40) (all p < 0.05, except for UC in Asians). The differences in Crohn's disease between Whites and minorities and the difference in UC between Whites and Blacks remained significant in multivariate analysis. In multivariate analysis, there was no regional difference in the prevalence of Crohn's disease, but the prevalence of UC was higher in the Northeast than the South (p < 0.05). Conclusions: There were significant racial/ethnic differences in the prevalence of IBD in the USA. The underlying etiology of these differences warrants additional research.