Association of Neighborhood Disadvantage and Anticoagulation for Patients with Atrial Fibrillation in the Veterans Health Administration: the REACH-AF Study

Background Atrial fibrillation (AF) is a common arrhythmia, the management of which includes anticoagulation for stroke prevention. Although disparities in anticoagulant prescribing have been well documented for individual socioeconomic factors, less is known about the association of neighborhood-level disadvantage and anticoagulation for AF. Objective To assess the association between neighborhood disadvantage and anticoagulant initiation for patients with incident AF. Design Retrospective cohort study. Participants A cohort of patients enrolled in the Veterans Health Administration (VA) with incident AF from January 2014 through December 2020 from the Race, Ethnicity, and Anticoagulant CHoice in Atrial Fibrillation (REACH-AF) Study. Main Measures The primary exposure was neighborhood disadvantage quantified using area deprivation index (ADI), classified by quintiles (Q). The outcomes were initiation of any anticoagulant therapy (warfarin or direct oral anticoagulant, DOAC) within 90 days of AF diagnosis and DOAC use among initiators. We used mixed effects logistic regression to assess the association between ADI and anticoagulant therapy, incorporating a fixed effect for treatment site and baseline patient, provider, and facility covariates. Key Results Among 161,089 patients, 105,489 (65.5%) initiated any anticoagulant therapy, and 78,903 (74.8%) used DOACs. Any anticoagulant therapy increased 3.2 percentage points (63.0% to 66.2%; p<.001) from Q1 to Q5, whereas DOAC use decreased 8.2 percentage points (79.4% to 71.2%; p<.0001) across quintiles. The adjusted odd ratios of any anticoagulant therapy were non-significantly different for Q2-Q5 than Q1. The adjusted odds of DOAC use decreased progressively from 0.89 (95% CI, 0.84-0.94) in Q2 to 0.77 (95% CI, 0.73-0.83) in Q5 compared to Q1 (p<.0001). Conclusions Among Veterans with incident AF, we observed similar initiation of any anticoagulant, though neighborhood deprivation was associated with decreased DOAC use among anticoagulant initiators. Future interventions to improve pharmacoequity in anticoagulant prescribing for AF should consider the role of neighborhood-level determinants of health inequities.