Factors driving anticoagulant selection in patients with atrial fibrillation in the United States.
With the introduction of novel oral anticoagulants (NOACs), the factors driving anticoagulant selection in atrial fibrillation (AF) in real-world practice are unclear. The goal was to examine whether and to what extent utilization has been driven by predictions of stroke risk (treatment benefit), bleeding risk (treatment harm), or prescription benefits' coverage. We extracted a cohort of patients with nonvalvular AF initiating anticoagulation from October 2010 to December 2012 from a large US database of commercial and Medicare supplement claims. Multivariable regression examined associations between ischemic stroke (CHA2DS2-VASc) and bleeding (Anticoagulation and Risk Factors in Atrial Fibrillation [ATRIA]) risk scores and benefits' generosity (proportion of costs covered by patients relative to total) with warfarin and novel oral anticoagulant (NOAC) selection and also between dabigatran and rivaroxaban. C-statistics and partial chi-square statistics were used to assess the variation explained. Of 70,498 patients initiating anticoagulation, 29.9% and 7.9% used dabigatran and rivaroxaban, respectively. Compared with warfarin, patients were less likely to receive an NOAC with high ischemic stroke risk (CHA2DS2-VASc ≥2; adjusted relative risk [aRR] 0.75, 95% confidence interval [CI] 0.72 to 0.77) and high bleeding risk (ATRIA ≥5; aRR 0.66, 95% CI 0.64 to 0.69) but more likely with good benefits' generosity (≤20% of costs borne by patient; aRR 2.03, 95% CI 1.92 to 2.16). Prescription generosity explained almost twice the model variation as either risk score. Compared with dabigatran, patients were more likely to fill rivaroxaban with high bleeding risk (aRR 1.16, 95% CI 1.09 to 1.24). In conclusion, patients with greater bleeding and ischemic stroke risk were more likely to initiate warfarin, but generous benefits more strongly predicted NOAC usage and drove more selection.
Division of Pharmaceutical Outcomes and Policy, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: jlauffenburger@partners.org.
Julie C
JC
Lauffenburger
Division of Pharmaceutical Outcomes and Policy, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Joel F
JF
Farley
Department of Cardiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Anil K
AK
Gehi
Division of Practice Advancement and Clinical Education, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Denise H
DH
Rhoney
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
M Alan
MA
Brookhart
Division of Pharmaceutical Outcomes and Policy, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Gang
G
Fang
D000284:Administration, Oral; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications* / Q000188:drug therapy; D002545:Brain Ischemia / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D003657:Decision Making; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015912:Thrombolytic Therapy / Q000379:methods* / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology
D000925:Anticoagulants