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.

Area Deprivation Index and Oral Anticoagulation in New Onset Atrial Fibrillation.

Objective: Oral anticoagulation is a standard of care for thromboembolic stroke prevention in individuals with atrial fibrillation (AF). Social determinants of health have had limited investigation in AF and particularly in access to anticoagulation. We examined the relation between area deprivation index (ADI) and anticoagulation in individuals at risk of stroke due to AF. Methods: We conducted a retrospective analysis of patients with incident, non-valvular AF from 2015-2020 receiving care at a large, regional health center. We extracted demographics, medications, and problem lists and used administrative coding to identify comorbid conditions and relevant covariates, and individual-level residential address to ascertain ADI. We examined the relation between ADI and receipt of prescribed oral anticoagulation (warfarin or direct-acting oral anticoagulant, or DOAC) at 90 days following AF diagnosis in multivariable-adjusted models. Results: Following exclusions, the dataset included 20,210 individuals (age 74.5±10.9 years; 51% women; 94% white race). In multivariable-adjusted analyses, individuals in the highest quartile of ADI had a 16% lower likelihood of receiving anticoagulation prescription than those in the lowest ADI quartile (Odds Ratio [OR] 0.84; 95% Confidence Interval [CI], 0.75-0.95) at 90 days following AF diagnosis. In those receiving anticoagulation, individuals in the highest ADI quartile had a 24% lower likelihood of receiving a DOAC prescription as opposed to warfarin prescription than those in the lowest quartile (OR 0.76; 95% CI, 0.60-0.96) at 90 days following AF diagnosis. Conclusions: We demonstrate the association of higher neighborhood deprivation as determined by ADI with decreased likelihood of (1) anticoagulation prescribing for stroke prevention in AF and (2) prescription of a DOAC when any oral anticoagulation is prescribed. Our results suggest neighborhood-based health inequities in the receipt of anticoagulation prescription for stroke prevention in AF in a large, regional health care system.