Differences in the socio‐economic distribution of inflammatory bowel disease and microscopic colitis

• Published in: Colorectal disease Vol. 19; no. 1; pp. 38 - 44
• Main Authors: Sonnenberg, A., Turner, K. O., Genta, R. M.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.01.2017
• Subjects: Adult; Affluence; African Americans - statistics & numerical data; Aged; Asian Americans - statistics & numerical data; Colitis; Colitis, Microscopic - epidemiology; Colitis, Microscopic - etiology; Colon; Colonoscopy - statistics & numerical data; Cross-Sectional Studies; Demographic characteristics; Demographics; Educational Status; Environment; environmental epidemiology; Environmental risk; European Continental Ancestry Group - statistics & numerical data; Female; Geography, Medical - statistics & numerical data; Health risks; Hispanic Americans - statistics & numerical data; Histopathology; Housing; Humans; Inflammatory bowel disease; Inflammatory bowel diseases; Inflammatory Bowel Diseases - epidemiology; Inflammatory Bowel Diseases - etiology; Intestine; Male; Middle Aged; Minority & ethnic groups; Population number; Postal codes; Prevalence; Risk Factors; Socioeconomic Factors; socio‐economic risk factors; United States - epidemiology; ZIP codes; Demographic characteristics; environmental epidemiology; ZIP codes; socio-economic risk factors
• ISSN: 1462-8910; 1463-1318
• DOI: 10.1111/codi.13378

Aim Inflammatory bowel disease (IBD) and microscopic colitis are characterized by different geographical distributions across the USA. In this cross‐sectional study we utilized demographic and socio‐economic information associated with individual ZIP codes to further delineate the epidemiological characteristics of the two diseases. Method A total of 813 057 patients who underwent colonoscopy between 2008 and 2014 were extracted from an electronic database of histopathology reports. The prevalence of patients with IBD or microscopic colitis was expressed as percentage of the population associated with specific demographic (age, sex, ethnicity) and socio‐economic characteristics (population size, housing value, annual income, tertiary education). Results Both diseases were more common among subjects from ZIP codes with predominantly White residents and less common among subjects from ZIP codes with predominantly non‐White residents such as Black, Hispanic and Asian. These ethnic variations were more pronounced in microscopic colitis than IBD. Markers of affluence, such as average residential house value and annual income, were positively associated with IBD and negatively with microscopic colitis. The prevalence of both diseases was positively correlated with tertiary education. Conclusion The occurrence of both IBD and microscopic colitis is influenced by environmental risk factors. The differences in the demographic, ethnic and socio‐economic distributions of the two diseases suggest that different sets of risk factors affect the two diseases and that their aetiology is unrelated.