Factors Correlated with Anticoagulation Choice in Primary Care Patients with Atrial Fibrillation and High Stroke Risk

The available data on anticoagulation therapy in real-world primary care settings for atrial fibrillation (AF) patients at high risk of stroke is limited.

To evaluate anticoagulation therapy and elucidate the factors associated with the selection between direct oral anticoagulants (DOACs) and warfarin.

This is a retrospective cohort study that included patients ≥ 18 years old at a large primary care outpatient group, a network of twenty clinics in the northeast United States between January 4, 2021 - January 4, 2023.

Oral anticoagulation therapy in AF patients with high risk of stroke (CHA₂DS₂-VASc score of ≥ 2 in men or ≥ 3 in women).

Among the 3,118 adult patients with AF and high risk of stroke (median age 77.90, IQR 71.66-84.50 years; male 57.6%), we found that older age (aOR 1.40, p = 0.003), greater BMI (25-29.9: aOR 1.32, p = 0.048; ≥ 30 aOR 1.42, p = 0.010), and taking more than five medications (aOR 2.28, p < 0.001) were more likely to be on an oral anticoagulant. Among those taking an OAC, having Medicare as the sole coverage (aOR 0.53, p = 0.032), male gender (aOR 0.69, p = 0.011), worse renal function (aOR 0.80, p = 0.021), and higher CHA₂DS₂-VASc score (aOR 0.88, p = 0.024) are more likely to be on warfarin than a DOAC. Patients taking more than five medications daily (6-10 medications: aOR 1.92, p = 0.013; ≥ 16: aOR = 2.10, p = 0.006) were more likely to be on an anticoagulant and may receive a DOAC over warfarin.

AF with high stroke risk adult patients are more likely to be on an oral anticoagulant if they are older, having BMI ≥ 25, or taking more than five medications. Medicare as the sole coverage, male gender, worse renal function, and higher CHA₂DS₂-VASc scores are factors associated with greater warfarin usage, while patients taking over five daily medications are more likely to be prescribed DOACs.