Original article—alimentary tract
The Prevalence and Geographic Distribution of Crohn’s Disease and Ulcerative Colitis in the United States

https://doi.org/10.1016/j.cgh.2007.07.012Get rights and content

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.

Section snippets

Study Design and Data Source

We analyzed the medical, surgical, and pharmaceutical insurance claims contained in the PharMetrics Patient-Centric Database (IMS Health, Watertown, MA) for the period January 1, 2003, through December 31, 2004. At the time of this study, this longitudinal, patient-level database included claims from 87 health plans in 33 states. The included plans capture a geographically diverse sample. The number of plans per major US census region (ie, East, South, Midwest, West) ranges from 12 to 34 (mean,

Source Population

The source population for this study included 8,997,731 individuals. Overall, 2,620,591 (29%) were children aged younger than 20 years and 6,377,140 (71%) were adults. Forty-eight percent of the population was male, 3% were insured by Medicaid programs, and the regional distribution was as follows: 29% Northeast, 27% South, 27% Midwest, and 17% West.

Utilization of Health Services by Identified Patients

Overall, 13,918 CD patients were identified. Over the 2-year period, 24% had at least 1 CD-related hospitalization, 77% had at least 1 pharmacy

Discussion

In our sample of close to 9 million Americans, the prevalence of CD and UC in children aged younger than 20 was 43 and 28 per 100,000, respectively. In adults, the respective prevalence rates were 201 and 238 per 100,000, respectively. Based on these data, we estimate that nearly 1 million Americans have IBD. There was a slight male predominance of CD in the pediatric population, with a female predominance in adulthood. The prevalence of UC did not vary by sex. The diagnosis of IBD appears to

References (19)

There are more references available in the full text version of this article.

Cited by (0)

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.

View full text