title: Racial Differences in Quality of Anticoagulation Therapy for Atrial Fibrillation (from the TREAT-AF Study).
abstract: The influence of race on quality of anticoagulation control is not well described. We examined the association between race, international normalized ratio (INR) monitoring intensity, and INR control in warfarin-treated patients with atrial fibrillation (AF). Using data from the Veterans Health Administration (VHA), we performed a retrospective cohort study of 184,161 patients with a new diagnosis of AF/flutter from 2004 to 2012 who received any VHA prescription within 90 days of diagnosis. The primary predictor was race, ascertained from multiple VHA and linked Medicare demographic files. The primary outcome was first-year and long-term time in therapeutic range (TTR) of INR 2.0 to 3.0. Secondary outcomes were INR monitoring intensity and warfarin persistence. Of the 116,021 patients who received warfarin in the cohort, INR monitoring intensity was similar across racial groups. However, TTR was lowest in blacks and highest in whites (first year 0.49 ± 0.23 vs 0.57 ± 0.21, p <0.001; long term 0.52 ± 0.20 vs 0.59 ± 0.18, p <0.001); 64% of whites and 49% of blacks had long-term TTR >55% (p <0.001). After adjusting for site and patient-level covariates, black race was associated with lower first-year and long-term TTRs (4.2% and 4.1% below the conditional mean, relative to whites; p <0.0001 for both). One-year warfarin persistence was slightly lower in blacks compared to whites (58% vs 60%, p <0.0001). In conclusion, in patients with AF anticoagulated with warfarin, differences in INR control are most evident among blacks, underscoring the need to determine if other types of intensive management or warfarin alternatives may be necessary to improve anticoagulation among vulnerable AF populations.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University; Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Celina
authors.initials: C
authors.lastname: Yong
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University.
authors.forename: Farnaz
authors.initials: F
authors.lastname: Azarbal
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University; Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Freddy
authors.initials: F
authors.lastname: Abnousi
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University; Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.affiliation: Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Susan
authors.initials: S
authors.lastname: Schmitt
authors.affiliation: Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Jun
authors.initials: J
authors.lastname: Fan
authors.affiliation: Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Claire T
authors.initials: CT
authors.lastname: Than
authors.affiliation: Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Aditya J
authors.initials: AJ
authors.lastname: Ullal
authors.affiliation: Department of Medicine, Maimonides Medical Center, Brooklyn, New York.
authors.forename: Felix
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California; Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University.
authors.forename: Ciaran S
authors.initials: CS
authors.lastname: Phibbs
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University; Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Frayne
authors.affiliation: Department of Medicine, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado.
authors.forename: P Michael
authors.initials: PM
authors.lastname: Ho
authors.affiliation: Department of Medicine, Emory University, Atlanta, Georgia.
authors.forename: Supriya
authors.initials: S
authors.lastname: Shore
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University; Department of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, California. Electronic address: mintu@stanford.edu.
authors.forename: Mintu P
authors.initials: MP
authors.lastname: Turakhia
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy / Q000208:ethnology*; D001777:Blood Coagulation / Q000187:drug effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011785:Quality Assurance, Health Care; D044469:Racial Groups; D012189:Retrospective Studies; D020521:Stroke / Q000208:ethnology / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin