Geographic Variation in the Use of Oral Anticoagulation Therapy in Stroke Prevention in Atrial Fibrillation

Abstract

Background and Purpose-Underuse of oral anticoagulation in stroke prevention in atrial fibrillation is common; however, it remains unknown how it varies geographically. The objective of this study was to evaluate geographic variation in oral anticoagulation use and in the initiation of new oral anticoagulants (NOACs). Methods-Using 2013 to 2014 claims data from a 5% random sample of Medicare beneficiaries, we identified patients newly diagnosed with atrial fibrillation who initiated NOACs (n=8659), warfarin (n=11 771) or no oral anticoagulation therapy (n=18 226) in 2013 to 2014. Each patient was assigned to 1 of the 306 Dartmouth hospital-referral regions based on his/her zip code. We const..