Epidemiology of Inflammatory Bowel Disease in a Cohort of US Black Women

Background and aims: Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, are inflammatory diseases of the gastrointestinal tract. The incidence of IBD is increasing in minority populations; however, little is known about the epidemiology and disease characteristics of IBD in Black women.

Methods: Our study population included participants in the Black Women's Health Study. Diagnosis of IBD was self-reported through the biennial questionnaires starting at baseline in 1995. We estimated the incidence of IBD according to age and geographic region. A follow-up supplementary questionnaire was also sent to a subset of participants who reported diagnosis of IBD to evaluate the accuracy of self-reported diagnosis and to assess disease characteristics.

Results: Through December 31, 2021, a total of 609 cases of IBD were reported, of which 142 were prevalent at baseline (prevalence, 0.24%), and 467 were incident (crude incidence rate, 33.2/100 000 person-years). The incidence of IBD was highest in the younger than 30 years age group and similar across geographic region. Among the participants who responded to the supplementary questionnaire, 57.1% had confirmed diagnosis of IBD.

Conclusions: In a large prospective cohort of US Black women, we found that the incidence of IBD was similar to previously published estimates in US White women. Future studies should focus on identifying risk factors for IBD in Black individuals in the United States.