Available online 9 July 2025

In the United States, Black patients with asthma experience higher exacerbation rates compared with non-Black patients.

To identify factors that might explain the exacerbation rate association with race in a cohort of patients with severe asthma (SA).

CHRONICLE was an observational study of US adults with SA treated by allergists/immunologists or pulmonologists. The analysis population was patients not receiving biologic treatment. Propensity score (PS) methods were used to identify factors associated with Black race. Non-Black–non-Hispanic or Latino patients (non-Black) were the control group. A generalized linear model (GLM) assessed the association between Black race and exacerbation rate, adjusted for the PS.

Between February 2018 and July 2022, 180 Black and 574 non-Black patients were eligible for PS analysis. Socioeconomic status was the strongest discriminator of race (C statistic of 0.75), followed by environment (0.65), demographics (0.64), smoking status (0.55), and comorbidities (0.55). Before adjusting for PS, the GLM showed a 1.28-fold higher exacerbation rate among Black patients compared with non-Black patients (RR [rate ratio] 1.28, 95% CI 1.01, 1.62; P=0.039). In the PS-adjusted GLM, Black race was no longer associated with exacerbation rate (RR: 0.87, 95% CI 0.56, 1.35; P=0.522). Results were similar for asthma-related emergency department and hospitalization rates.

Higher exacerbation rates in Black patients with SA may be explained by factors associated with Black race, such as socioeconomic status. Addressing socioeconomic disparities and social determinants of health may help reduce the exacerbation risk difference observed between Black and non-Black patients with SA.

NCT03373045

severe asthma

exacerbations

racial disparities

social determinants of health

real-world health care disparities

generalized linear model

maintenance systemic corticosteroids

social determinants of health

© 2025 Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology