Racial and Socioeconomic Differences in Real-World Use of Biologic Therapy for Asthma

Purpose: Determine if there is a difference in race, socioeconomic factors and baseline asthma severity at the time of biologic initiation and whether those characteristics are associated with response to therapy within 18 months of initiation. Additionally, evaluate racial differences in clinic engagement, healthcare utilization, and biologic adherence. Patients and Methods: Retrospective review of patients initiating biologic therapy for moderate-severe asthma from January 1, 2019–June 30, 2022. Multiple linear regression analyses were performed to examine whether race and socioeconomic status were associated with race-neutral percent predicted forced expiratory volume in one second (ppFEV1) prior to biologic prescription and within 18 months post biologic initiation. Differences in clinic engagement and healthcare utilization by race were assessed using Wilcoxon rank sum tests. Adherence was calculated using proportion of days covered (PDC). Results: Patients (N=215) were White (69%) or Black or African American (27%). Most had commercial (54%) or Medicare (22%) insurance. At the time of biologic initiation, Black or African American/Other patients were estimated to have a 6.9% lower ppFEV1 than White patients ( p =0.057), had a higher percentage of no-show appointments ( p < 0.001), and there was a significant difference in distribution of percentage of appointments cancelled between White and Black or African American/Other patients ( p = 0.0038). No significant differences in healthcare utilization were found by race. At follow-up, racial differences in ppFEV1 were 0.6% after adjusting for covariates and baseline ppFEV1 ( p =0.893). Median PDC of biologic therapy was 0.96 (IQR 0.88– 1.00), with no significant difference between race. Socioeconomic status was similar between the cohorts. Conclusion: Although not statistically significant, our findings suggest a possible trend where Black or African American/Other patients had lower ppFEV1 at the time of biologic initiation, indicating an opportunity for earlier interventions.