The Prevalence and Geographic Distribution of Crohn's Disease and Ulcerative Colitis in the United States

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doi:10.1016/j.cgh.2007.07.012 Copyright © 2007 AGA Institute Published by Elsevier Ltd.

Original article—alimentary tract

The Prevalence and Geographic Distribution of Crohn’s Disease and Ulcerative Colitis in the United States

D. Kappelman, ‡, , , Sheryl L. Rifas–Shiman‡, Ken Kleinman‡, Dan Ollendorf§, Athos Bousvaros, J. Grand and A. Finkelstein‡, ¶ ‡Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston, MassachusettsCenter for Inflammatory Bowel Disease, Division of Gastroenterology and Nutrition, Children’s Hospital Boston and Harvard Medical School, Boston, Massachusetts§IMS Health, Watertown, Massachusetts¶Division of General Pediatrics, Children’s Hospital Boston and Harvard Medical School, Boston, Massachusetts Available online 29 September 2007.

Background & Aims: Previous US studies of inflammatory bowel disease (IBD) prevalence have sampled small, geographically restricted populations and may not be generalizable to the entire nation. This study sought to determine the prevalence of Crohn’s disease (CD) and ulcerative colitis (UC) in a large national sample and to compare the prevalence across geographic regions and other sociodemographic characteristics.

Methods: We analyzed the health insurance claims for 9 million Americans, pooled from 87 health plans in 33 states, and identified cases of CD and UC using diagnosis codes. Prevalence was determined by dividing the number of cases by the number of persons enrolled for 2 years. Logistic regression was used to compare prevalence estimates by geographic region, age, sex, and insurance type (Medicaid vs commercial).

Results: The prevalence of CD and UC in children younger than 20 years was 43 (95% confidence interval [CI], 40–45) and 28 (95% CI, 26–30) per 100,000, respectively. In adults, the prevalence of CD and UC was 201 (95% CI, 197–204) and 238 (95% CI, 234–241), respectively. The prevalence of both conditions was lower in the South, compared with the Northeast, Midwest, and West. IBD appears to be more common in commercially insured individuals, compared with those insured by Medicaid.

Conclusions: This estimation of the prevalence of IBD in the US should help quantify the overall burden of disease and inform the planning of appropriate clinical services.

Abbreviations: CD, Crohn’s disease; CI, confidence interval; IBD, inflammatory bowel disease; OR, odds ratio; UC, ulcerative colitis

Supported in part by the National Institute of Diabetes and Digestive and Kidney Diseases (grant 5T32DK007477-24 to M.D.K.), supported in part by the Wolpow Family Fund (R.J.G. and A.B.), and supported in part by General Clinical Research Center (grant RR M01002172 to R.J.G.). Partial support for this analysis was provided by an unrestricted educational grant from Proctor and Gamble to the IBD Center at Children’s Hospital Boston.Address requests for reprints to: D. Kappelman, MD, UNC Division of Pediatric Gastroenterology, 130 Mason Farm Road, CB #7220, 5th Floor Bioinformatics Building, Chapel Hill, North Carolina 27599-7220. fax: .

Clinical Gastroenterology and Hepatology Volume 5, Issue 12, December 2007, Pages 1424-1429