ORIGINAL ARTICLE Comparison of the Natural History of Ulcerative Colitis in African Americans and Non-Hispanic Caucasians: A Historical Cohort Study Lauren Moore, MD, MA, Kristin Gaffney, DO, Rocio Lopez, MS, MPH, and Bo Shen, MD Background: There has been an increase in the number of studies on the interaction of African American race and the natural history of inflammatory bowel disease (IBD). However, the results from these studies have been conflicting. We aimed to characterize the natural history of ulcerative colitis (UC) in a cohort of African American patients compared with Caucasian controls. Methods: We performed a retrospective chart review of patients with UC who were seen in our IBD Center from 2000 to 2010. In all, 102 African American patients and 209 Caucasian patients were included. We assessed clinical variables related to the natural history of UC as well as outcome variables that reflected disease severity. Results: African American patients had a shorter median duration (8.0, interquartile range [IQR] ¼ 4.0, 14.0) of UC than Caucasians (10.0, IQR ¼ 6.0, 18.0) (P ¼ 0.006). African American disease patients had more distal disease than controls. African Americans were significantly less likely to use corticosteroids (74.2% vs. 88.8%, P ¼ 0.002), or use immunomodulators (25.8% vs. 69.7%, P < 0.001) than Caucasians. Adjusted multivariate analysis showed that ethnicity was not a risk factor for colectomy (hazard ratio [HR] ¼ 1.6; 95% confidence interval [CI]: 0.78, 3.3). Conclusions: There appear to be differences in the natural history of UC in our African American patients when compared with Caucasian controls, while ethnicity was not shown to be a risk factor for colectomy. (Inflamm Bowel Dis 2012;18:743–749) Key Words: race, inflammatory bowel disease, natural history, disease severity, colectomy U lcerative colitis (UC) is a form of inflammatory bowel disease (IBD) localized to the colon and rectum that can cause significant morbidity and even mortality. The eti- ology and pathogenesis of IBD is multifactorial, resulting from complex interactions of genetics, environmental fac- tors, intestinal microflora, and host immunity. 1 In the past two decades the IBD community has begun to question if African American race may work in concert with these fac- tors to impact UC disease severity. 2 However, there are few published data on the disease course or natural history of the disease in African Americans and the data that do exist have been conflicting. The incidence data on race and UC frequently cited in the literature comes from an epidemiologic study per- formed in Olmsted County, Minnesota, 3 where there were limited minority populations. Incidence rates of UC were found to be significantly less in African Americans than Caucasians (0.45/100,000 vs. 3.5/100,000). 3 New popula- tion data on the incidence of UC in African Americans is missing from the literature. 4 However, data reported from a large health maintenance organization in California reported prevalence rates of 43.6/100,000 in Caucasians and 29.8/100,000 in African Americans. 3 Recent data on IBD-related hospital admission rates among members of the Kaiser Permanente Medical Care Program in California showed no difference between African American and Cau- casian patients. 5 Survey data from Baltimore suggest that hospitalization rates for African American women with UC between 1977 to 1979 were 1.6 time higher than those of Caucasian women with UC. 6,7 While the exact burden of disease is unclear, these data suggest that the numbers of African Americans with UC are greater than once thought, making the investigation of disease in this population espe- cially relevant. Results from studies comparing racial differences in disease behavior and severity of IBD have been conflicting. Some have suggested that there are differences in disease behavior, extraintestinal manifestations (EIMs), response to Received for publication April 9, 2011; Accepted May 16, 2011. From the Departments of Gastroenterology and Quantitative Health Sciences and the Cleveland Clinic Lerner College of Medicine, the Cleveland Clinic Foundation, Cleveland, Ohio. Reprints: Bo Shen, MD, Department of Gastroenterology-A31, the Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195 (e-mail: shenb@ccf. org). Copyright V C 2011 Crohn’s & Colitis Foundation of America, Inc. DOI 10.1002/ibd.21796 Published online 17 June 2011 in Wiley Online Library (wileyonlinelibrary. com). Inflamm Bowel Dis  Volume 18, Number 4, April 2012 743