title: Substantial differences in initiation of oral anticoagulant therapy and clinical outcome among non-valvular atrial fibrillation patients treated in inpatient and outpatient settings.
abstract: OBJECTIVE
  Patients with atrial fibrillation (AF) are encountered and treated in different healthcare settings, which may affect the quality of care. We investigated the use of oral anticoagulant (OAC) therapy and the risk of thrombo-embolism (TE) and bleeding, according to the healthcare setting.
  
  
  RESULTS
  Using national Danish registers, we categorized non-valvular AF patients (2002-11) according to the setting of their first-time AF contact: hospitalization (inpatients), ambulatory (outpatients), or emergency department (ED). Event rates and hazard ratios (HRs), calculated using Cox regression analysis, were estimated for outcomes of TE and bleeding. We included 116 051 non-valvular AF patients [mean age 71.9 years (standard deviation 14.1), 51.3% males], of whom 55.2% were inpatients, 41.9% outpatients, and 2.9% ED patients. OAC therapy 180 days after AF diagnosis among patients with a CHADS2 ≥ 2 was 42.1, 63.0, and 32.4%, respectively. Initiation of OAC therapy was only modestly influenced by CHADS2 and HAS-BLED scores, regardless of the healthcare setting. The rate of TE was 4.30 [95% confidence interval (CI) 4.21-4.40] per 100 person-years for inpatients, 2.28 (95% CI 2.22-2.36) for outpatients, and 2.30 (95% CI 2.05-2.59) for ED patients. The adjusted HR of TE, with inpatients as reference, was 0.74 (95% CI 0.71-0.77) for outpatients and 0.89 (95% CI 0.79-1.01) for ED patients.
  
  
  CONCLUSIONS
  In a nationwide cohort of non-valvular AF patients, outpatients were much more likely to receive OAC therapy and had a significantly lower risk of stroke/TE compared with inpatients and ED patients. However, across all settings investigated, OAC therapy was far from optimal.
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark andersmik@icloud.com.
authors.forename: Anders Pretzmann
authors.initials: AP
authors.lastname: Mikkelsen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark.
authors.forename: Morten Lock
authors.initials: ML
authors.lastname: Hansen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark.
authors.forename: Jonas Bjerring
authors.initials: JB
authors.lastname: Olesen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark.
authors.forename: Morten Winther
authors.initials: MW
authors.lastname: Hvidtfeldt
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark.
authors.forename: Deniz
authors.initials: D
authors.lastname: Karasoy
authors.affiliation: Medical Department, Hospital Unit West, 7400 Herning, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Husted
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43, 8200 Aarhus N, Denmark.
authors.forename: Søren Paaske
authors.initials: SP
authors.lastname: Johnsen
authors.affiliation: Department of Cardiology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: Axel
authors.initials: A
authors.lastname: Brandes
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark National Institute of Public Health, University of Southern Denmark, Øster Farimagsgade 5 A, 1353 Copenhagen K, Denmark.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Gislason
authors.affiliation: Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Post 635, 2900 Hellerup, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Lamberts
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000592:standards; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D016009:Chi-Square Distribution; D003718:Denmark; D005260:Female; D054625:Healthcare Disparities / Q000592:standards; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D007297:Inpatients; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000592:standards; D016016:Proportional Hazards Models; D019984:Quality Indicators, Health Care; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Atrial fibrillation; Oral anticoagulants; Stroke; Thrombo-embolism; Warfarin