title: Patterns of initiation of oral anticoagulants in patients with atrial fibrillation- quality and cost implications.
abstract: BACKGROUND
  Dabigatran, rivaroxaban, and apixaban have been approved for use in patients with atrial fibrillation based upon randomized trials demonstrating their comparable or superior efficacy and safety relative to warfarin. Little is known about their adoption into clinical practice, whether utilization is consistent with the controlled trials on which their approval was based, and how their use has affected health spending for patients and insurers.
  
  
  METHODS
  We used medical and prescription claims data from a large insurer to identify patients with nonvalvular atrial fibrillation who were prescribed an oral anticoagulant in 2010-2013. We plotted trends in medication initiation over time, assessed corresponding insurer and patient out-of-pocket spending, and evaluated the cumulative number and cost of anticoagulants. We identified predictors of novel anticoagulant initiation using multivariable logistic models. Finally, we estimated the difference in total drug expenditures over 6 months for patients initiating warfarin versus a novel anticoagulant.
  
  
  RESULTS
  There were 6893 patients with atrial fibrillation that initiated an oral anticoagulant during the study period. By the end of the study period, novel anticoagulants accounted for 62% of new prescriptions and 98% of anticoagulant-related drug costs. Female sex, lower household income, and higher CHADS2, CHA2DS2-VASC, and HAS-BLED scores were significantly associated with lower odds of receiving a novel anticoagulant (P <.001 for each). Average combined patient and insurer anticoagulant spending in the first 6 months after initiation was more than $900 greater for patients initiating a novel anticoagulant.
  
  
  CONCLUSIONS
  This study demonstrates rapid adoption of novel anticoagulants into clinical practice, particularly among patients with lower CHADS2 and HAS-BLED scores, and high health care cost consequences. These findings provide important directions for future comparative and cost-effectiveness research.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass; Section of Cardiovascular Medicine, Department of Medicine, Yale School of Medicine, New Haven, Conn; Center for Outcomes Research and Evaluation, Yale-New Haven Health Services Corporation, New Haven, Conn.
authors.forename: Nihar R
authors.initials: NR
authors.lastname: Desai
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass.
authors.forename: Alexis A
authors.initials: AA
authors.lastname: Krumme
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schneeweiss
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass; CVS Caremark, Woonsocket, RI.
authors.forename: William H
authors.initials: WH
authors.lastname: Shrank
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass.
authors.forename: Gregory
authors.initials: G
authors.lastname: Brill
authors.affiliation: Aetna, Hartford, Conn.
authors.forename: Edmund J
authors.initials: EJ
authors.lastname: Pezalla
authors.affiliation: Aetna, Hartford, Conn.
authors.forename: Claire M
authors.initials: CM
authors.lastname: Spettell
authors.affiliation: CVS Caremark, Woonsocket, RI.
authors.forename: Troyen A
authors.initials: TA
authors.lastname: Brennan
authors.affiliation: CVS Caremark, Woonsocket, RI.
authors.forename: Olga S
authors.initials: OS
authors.lastname: Matlin
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass.
authors.forename: Jerry
authors.initials: J
authors.lastname: Avorn
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass. Electronic address: nchoudhry@partners.org.
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000191:economics* / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001562:Benzimidazoles / Q000191:economics / Q000627:therapeutic use; D000069604:Dabigatran; D016208:Databases, Factual; D017723:Drug Utilization Review; D065427:Factor Xa Inhibitors / Q000191:economics / Q000627:therapeutic use; D005252:Fees, Pharmaceutical; D005260:Female; D006801:Humans; D007182:Income; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000191:economics / Q000627:therapeutic use; D015999:Multivariate Analysis; D011720:Pyrazoles / Q000191:economics / Q000627:therapeutic use; D011728:Pyridones / Q000191:economics / Q000627:therapeutic use; D018570:Risk Assessment; D000069552:Rivaroxaban; D012720:Severity of Illness Index; D012737:Sex Factors; D020521:Stroke / Q000517:prevention & control; D013876:Thiophenes / Q000191:economics / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology; D014812:Vitamin K / Q000037:antagonists & inhibitors; D014859:Warfarin / Q000191:economics / Q000627:therapeutic use; D055815:Young Adult; D015091:beta-Alanine / Q000031:analogs & derivatives / Q000191:economics / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D001562:Benzimidazoles; D065427:Factor Xa Inhibitors; D009025:Morpholines; D011720:Pyrazoles; D011728:Pyridones; D013876:Thiophenes; D015091:beta-Alanine; D014812:Vitamin K; C522181:apixaban; D014859:Warfarin; D000069552:Rivaroxaban; D000069604:Dabigatran
keywords: Factor Xa inhibitor; Novel anticoagulant; Patterns of use; Vitamin K antagonist; Warfarin