Racial or ethnic differences on treatment adherence and persistence among patients with inflammatory bowel diseases initiated with biologic therapies

Background Inflammatory bowel disease (IBD) is a chronic disease with the potential for significant morbidity in case of suboptimal treatment (e.g. low treatment adherence). In spite of immense research in IBD, literature on association of IBD with race/ethnicity is fragmented. In this study, we aimed to evaluate the association between race/ethnicity and treatment adherence and persistence among patients with Crohn’s disease (CD) or ulcerative colitis (UC) initiated with biologic therapies. Methods This observational, retrospective study utilized the Optum Clinformatics (Optum) Extended Data Mart Socioeconomic Status (SES) database. Adult patients with ≥ 2 medical claims for CD or UC diagnosis, ≥ 1 medical or pharmacy claim for corresponding FDA-approved biologic therapy, and a ≥ 12-month pre-index (index date: date of the first biologic medical/pharmacy claim) continuous health plan enrollment were included. Treatment adherence was measured as the proportion of days covered of ≥ 80% and treatment persistence by the number of days from the index date to the biologics discontinuation date. Switching among biologics was allowed for both treatment adherence and treatment persistence. Multivariable regression analyses were performed to evaluate the association between race/ethnicity and treatment adherence/persistence. Results Among patients with CD ( N = 1430) and UC ( N = 1059) included, majority were White (CD: 80.3%, UC: 78.3%), followed by African Americans (AA; CD: 10.5%, UC: 9.7%). Among patients with CD, AA were significantly less likely to adhere to biologics (adjusted OR [95%CI]: 0.61 [0.38; 0.99]) and more likely to discontinue biologics earlier (adjusted HR [95%CI]: 1.52 [1.16; 2.0]) during the follow-up period compared to Whites, after adjusting for other patient sociodemographic and clinical characteristics. Among patients with UC, no significant differences in the treatment adherence/persistence were observed between different races/ethnicities. Conclusions Patients with CD were found to display racial differences in the treatment adherence and persistence of biologics, with significantly lower adherence and earlier discontinuation in AA compared to Whites. Such differences were not observed in patients with UC. Future studies are warranted to understand the possible reasons for racial differences, particularly in patients with CD.