Disparities in α1-Antitrypsin Deficiency Testing and Treatment in US Adults.

Importance: α1-Antitrypsin deficiency (AATD) is underdiagnosed despite guidelines for broad testing, and the factors associated with low testing and treatment are not well known. Objective: To identify factors associated with low AATD testing and augmentation therapy in individuals with chronic obstructive pulmonary disease (COPD) and asthma. Design, Setting, and Participants: This is a retrospective, multicenter cohort study using national electronic health record data from the Veterans Health Administration from January 1, 2020, to December 31, 2024. Data analysis was conducted from July to October 2025. Participants were individuals with a diagnosis of COPD and/or asthma (≥2 International Classification of Diseases, Ninth Revision, or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes). Exposure: Individual demographics, comorbidities, tobacco use, rural-urban residence, Social Vulnerability Index (SVI), and drive time to the specialty care facility. Main Outcomes and Measures: The primary outcomes were prevalence of and factors associated with AATD testing and augmentation therapy prescription. Multivariable regression models were used, adjusting sequentially for demographics, comorbidities, tobacco use, rural-urban residence, SVI, and drive time to the specialty care facility. Results: Among 2 384 913 individuals with COPD and/or asthma (mean [SD] age, 64.2 [14.3] years; 178 898 female [7.5%]; 16 778 [0.7%] American Indian or Alaska Native; 14 996 [0.7%] Asian; 331 202 Black or African American [15.3%]; 19 029 [0.9%] Native Hawaiian or Pacific Islander; 1 787 951 White [82.4%]), 138 278 (5.8%) underwent testing. In fully adjusted models, cirrhosis (adjusted odds ratio [aOR], 6.40; 95% CI, 6.29-6.51) and bronchiectasis (aOR, 3.73; 95% CI, 3.59-3.87) were associated with higher odds of testing. Older ages and active tobacco use were associated with lower odds of testing. Rural-urban residence and SVI had similar odds across categories. Longer drive times were associated with progressively lower odds of testing (>90 vs ≤30 minutes; aOR, 0.63; 95% CI, 0.62-0.65). Of 8564 with AATD diagnosis, 320 (3.7%) were prescribed augmentation therapy and showed a similar pattern as testing, occurring less often among patients from minoritized racial and ethnic groups, those actively using tobacco, and those with longer drive times to specialty care, and more often among those with cirrhosis and bronchiectasis. Conclusions and Relevance: In this cohort study of individuals with COPD and/or asthma, AATD testing and augmentation therapy were profoundly low. System-level reform is needed to bridge gaps across age, comorbidities, tobacco use, and health care access.