The Prevalence of Inflammatory Bowel Disease in the United States Military Healthcare Population: 2011 ACG Presidential Poster

Abstract

Purpose: To determine the prevalence of inflammatory bowel disease (IBD) within the military health care system (Tricare) in the United States and in specific demographic subgroups. Methods: Using ICD9 codes, we identified the total number of patients with Crohn's disease (CD) or ulcerative colitis (UC) seen within the military healthcare system (Tricare) from January to December 2009. This database is comprised of all active duty military, dependents of military personnel and retired military populations. The overall prevalence of IBD, CD and UC was calculated, as well as the prevalence for various subgroups including age, gender and geographic location. We examined the prevalence based on 4 geographic regions (U.S. Census Bureau regions: Northeast, South, Midwest and West) and also compared Northern vs. Southern states using the 37th parallel latitude. Results: 35,404 cases of IBD were identified of 10.2 million military healthcare beneficiaries establishing an overall IBD prevalence of 348 per 100,000 (95% CI, 344-351). The prevalence of CD and UC were 146 and 202 per 100,000, respectively. IBD was more prevalent in females compared to males (RR 1.47; 417 vs. 284 per 100,000). The mean age (+SD, years) of our overall IBD, CD and UC populations were 51+19, 50+19, and 53+18, respectively. There was increasing trend in the prevalence of IBD with increasing age, peaking in the 70s (RR = 3.5 compared to 20s). A similar trend regarding age was seen in both UC and CD subgroups. The prevalence of IBD, CD, and UC in the pediatric population (< 20 years old) was 71, 40, and 31 per 100,000, respectively. IBD was least prevalent in the West region compared to the Northeast, South, and Midwest regions (322 vs. 389, 379, 366 per 100,000, respectively, binomial p<.05). When comparing Northern vs. Southern states, there was no difference in prevalence (339 vs. 333 per 100,000, respectively). Conclusion: This large population study establishes a similar prevalence of IBD (348 per 100,000) in the military health care population compared to other published data. There was an increased prevalence of IBD, CD, and UC in females and with increasing age. Geographically, the western United States had a significantly lower prevalence compared to the remainder of the country but there was no difference between Northern and Southern latitude.