Abstract Rationale People of color have disproportionally higher prevalence of and poor outcomes from asthma in the United States; this is despite the advent of highly effective biologic therapy that reduces morbidity/mortality in asthma. We sought to define racial differences in biologic prescription rates, the impact of insurance status on those racial differences, and whether the efficacy of biologics varies by race. Methods We conducted a retrospective cohort study of self-reported White or Black adult and pediatric patients eligible for any FDA-approved biologic from the Johns Hopkins Health System between July 2016 and October 2025. Eligibility was defined by an ICD-10 diagnosis of asthma and a prescription for medium-to-high dose inhaled corticosteroid and long-acting beta agonist. Insurance status was dichotomized as private versus public/self-pay. Exacerbations were defined as an ED visit/hospitalization for asthma or an outpatient visit with oral corticosteroid prescription. We performed a mediation analysis using additive hazard models to assess absolute hazard differences in biologic prescription by race with insurance as the mediator of interest, adjusted for age, allergic phenotype, specialty care, and exacerbation history. Among patients receiving a biologic, we evaluated efficacy using a zero-inflated negative binomial mixed effects model comparing patient-level exacerbation rates in the year before versus after biologic prescription. Results A total of 25,187 patients were eligible for a biologic, with 853 patients receiving a biologic prescription. Of those prescribed, 90% were adults, 36% were Black race, and 57% had private insurance. At one year since eligibility, Black individuals received 2.8 fewer prescriptions per 1,000 person-years than White individuals (95% CI: -0.8-5.9), and mediation analysis indicated insurance only accounted for 15% of that difference (0.4 prescriptions per 1,000 person-years, 95% CI: 0.2-0.6). Exacerbation rates were 1.8 times higher in Black vs White patients before biologic prescription (Figure). Using a generalized linear mixed model, exacerbation rates decreased similarly among Black and White patients comparing the year after biologic prescription to the year before (relative risk: Black 0.76, 95% CI: 0.50-1.13; White 0.88, 95% CI: 0.58-1.33) (Figure). Conclusions There is a significant racial difference in prescription of biologics for Black versus White patients that is incompletely explained by insurance status alone. Biologics are noted to be equally efficacious across races in reducing exacerbations once initiated, despite higher exacerbation rates among Black individuals. Further studies are required to better understand why this racial difference exists and how it can be mitigated. This abstract is funded by: None
Parker et al. (Fri,) studied this question.