Direct Oral Anticoagulants and Warfarin for Atrial Fibrillation Treatment: Rural and Urban Trends in Medicare Beneficiaries.

BACKGROUND: Data are needed on the use of oral anticoagulation in patients with atrial fibrillation (AF) in rural versus urban areas, including the initiation of direct oral anticoagulants (DOACs). OBJECTIVE: We used Medicare data to examine rural/urban differences in anticoagulation use in patients with AF. METHODS: We identified incident AF in a 20% sample of fee-for-service Medicare beneficiaries (aged ≥ 65 years) from 2011 to 2016 and collected ZIP code and covariates at the time of AF. We identified the first anticoagulant prescription filled, if any, following AF diagnosis. We categorized beneficiaries into four rural/urban areas using rural-urban commuting area codes and used Poisson regression models to compare anticoagulant use. RESULTS: We included 447,252 patients with AF (mean age 79 ± 8 years), of which 82% were urban, 9% large rural, 5% small rural, and 4% isolated. The percentage who initiated an anticoagulant rose from 34% in 2011 to 53% in 2016, paralleling the uptake of DOACs. In a multivariable-adjusted analysis, those in rural areas (vs. urban) were more likely to initiate an anticoagulant. However, rural beneficiaries (vs. urban) were less likely to initiate a DOAC; those in isolated areas were 17% less likely (95% confidence interval [CI] 13-20), those in small rural areas were 12% less likely (95% CI 9-15), and those in large rural areas were 10% less likely (95% CI 8-12). CONCLUSION: Among Medicare beneficiaries with AF, anticoagulation use was low but increased over time with the introduction of DOACs. Rural beneficiaries were less likely to receive a DOAC.