title: Age is associated with time in therapeutic range for warfarin therapy in patients with atrial fibrillation.
abstract: BACKGROUND
  Warfarin is the most prescribed oral anticoagulant used for preventing stroke in patients with atrial fibrillation. Time in the therapeutic range (TTR) has been accepted as the best method to evaluate the quality of warfarin therapy. The main aim of the present study was to evaluate the impact of variables on the time in the therapeutic range for warfarin therapy in patients with atrial fibrillation from a referral cardiovascular hospital.
  
  
  METHODS
  This retrospective study included 443 patients were included (190 patients with age < 65 years and 253 patients with age ≥65 years) from 2011 to 2014 and TTR was computed according to Rosendaal's method.
  
  
  RESULTS
  Patients with age ≥65 years had higher TTR value (67±22%) compared with patients with < 65 years (60±24%) (p = 0.004). In a linear regression model, only age ≥65 years emerged as a significant predictor of greater TTR values. In multivariate logistic regression model, the variable age ≥65 years was associated with higher OR for having a TTR higher than the median value (OR = 2.17, p < 0.001).
  
  
  CONCLUSIONS
  We suggest that the age influenced TTR through greater drug adherence. Strategies for increasing drug adherence might improve quality of warfarin anticoagulation.
authors.affiliation: Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Leiliane Rodrigues
authors.initials: LR
authors.lastname: Marcatto
authors.affiliation: Clinical Cardiology Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Sacilotto
authors.affiliation: Clinical Cardiology Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Francisco Carlos da Costa
authors.initials: FC
authors.lastname: Darrieux
authors.affiliation: Clinical Cardiology Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Denise Tessariol
authors.initials: DT
authors.lastname: Hachul
authors.affiliation: Clinical Cardiology Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Maurício Ibrahim
authors.initials: MI
authors.lastname: Scanavacca
authors.affiliation: Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Jose Eduardo
authors.initials: JE
authors.lastname: Krieger
authors.affiliation: Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Alexandre Costa
authors.initials: AC
authors.lastname: Pereira
authors.affiliation: Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Paulo Caleb Junior Lima
authors.initials: PC
authors.lastname: Santos
mesh_terms: D000367:Age Factors; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Gerotarget; TTR; age; atrial fibrillation; polymorphisms; warfarin