Veterans with Atrial Fibrillation at VAMCs Serving More Minorities Are Less Likely to Receive Anticoagulation for Stroke Prevention
BACKGROUND:
Atrial fibrillation (AF) is the most common cardiac rhythm disorder in the U.S, affecting up to 6 million adults. Oral anticoagulant (OAC) therapy significantly reduces the risk of ischemic stroke in individuals with AF and is the standard of care for patients with moderate to high stroke risk. This study sought to determine whether medical center racial/ethnic composition is associated with initiation of anticoagulant therapy for Veterans with incident AF. The researchers also assessed whether there are individual-level racial/ethnic differences in the associations between medical center racial/ethnic composition and initiation of anticoagulant therapy and the interaction between these two factors. Researchers examined the racial/ethnic composition—defined as the proportion of Veterans from minoritized racial/ethnic groups—of 140 VAMCs and categorized the VAMCs into quartiles, with quartile 1 having the lowest percentage of minoritized Veterans (i.e., Asian, American Indian/Alaska Native, Black, or Hispanic).The study cohort consisted of 89,791 Black (10%), White (86%), and Hispanic (4%) Veterans diagnosed with incident AF from 2018–2021. The main measure was the likelihood of initiating any anticoagulant therapy, defined as the first outpatient prescription for warfarin or a direct-acting oral anticoagulant (DOAC) that was filled in VA within 90 days of an index AF diagnosis, adjusting for sociodemographics, medical comorbidities, and facility factors. Overall, 64,770 (72%) Veterans initiated any anticoagulant, 60,362 (67%) initiated DOAC therapy, and 4,408 (5%) initiated warfarin.
FINDINGS:
- Initiation of any anticoagulant and warfarin therapy was significantly lower among Veterans at VAMCs serving larger proportions of minoritized patients. There was no association between initiation of newer, guideline-recommended DOAC therapy and VAMC racial/ethnic composition.
- Compared to White Veterans, Black and Hispanic Veterans had lower rates of any anticoagulant and DOAC therapy initiation but higher rates of warfarin initiation across all quartiles of VAMC racial/ethnic composition.
- Although significant Black-White and Hispanic-White differences in initiation of any anticoagulant, DOAC, and warfarin therapy were observed, interactions between Veteran race/ethnicity and VAMC racial composition were not significant.
IMPLICATIONS:
- Interventions to improve anticoagulant prescribing at minority-serving facilities are needed to improve quality and achieve pharmacoequity for AF care in VA.
- Higher rates of warfarin therapy among Black and Hispanic Veterans suggest differential rates of de-implementation of older therapies for stroke prevention, indicating that strategies to improve equitable deprescribing warrant further study.
LIMITATIONS:
- There may have been unmeasured confounding along with limited capture of social determinants that may influence anticoagulant decision making.
AUTHOR/FUNDING INFORMATION:
This study was funded by HSR. Dr. Essien is with HSR’s Center for Healthcare Innovation, Implementation & Policy (CSHIIP) and is supported by an HSR Career Development Award. Ms. Kim and Dr. Hausmann are with HSR's Center for Health Equity Research and Promotion (CHERP).
Essien UR, Kim N, Hausmann LRM, et al. Veterans Affairs Medical Center Racial and Ethnic Composition and Initiation of Anticoagulation for Atrial Fibrillation. JAMA Network Open. June 24, 2024;7(6)e2418114.
