title: Effectiveness and safety of drugs used for stroke prevention in a cohort of non-valvular atrial fibrillation patients from a primary care electronic database.
abstract: The aim of this study was to assess effectiveness and safety of antithrombotics for stroke prevention in non-valvular atrial fibrillation in real-use conditions.
  
  
  
  We used a population-based retrospective cohort study. Information emerges from SIDIAP, a database containing anonymized information from electronic health records from 274 primary healthcare centres of the Catalan Health Institute, Catalonia (Spain), with a reference population of 5 835 000 people. Population includes all adults with a new diagnosis of non-valvular atrial fibrillation registered in SIDIAP from 2007 to 2012. The main outcome of antithrombotics' effectiveness was stroke. The main outcomes of safety were cerebral and gastrointestinal haemorrhages. We also estimated all-cause mortality. We used multivariable Cox proportional hazard models to examine association between antithrombotic treatment and main outcomes.
  
  
  
  We included 22 205 subjects with non-valvular atrial fibrillation; 40.8% initiated on vitamin K antagonists (VKA), 33.4% on antiplatelets and 25.8% untreated. We found stroke-risk reduction with VKA, hazard ratio (HR) 0.72 (95% confidence interval (CI), 0.58-0.91), also seen in patients with CHADS2≥ 2, HR 0.65 (95%CI, 0.49-0.86), and CHA2DS2-VASc ≥ 2, HR 0.66 (95%CI, 0.52-0.84). We observed a higher risk of digestive bleeding with antiplatelets, HR 1.32 (95%CI, 1.01-1.73). Both VKA and antiplatelets were associated with reduction of all-cause mortality risk; HR 0.55 (95%CI, 0.49-0.62) and HR 0.89 (95%CI, 0.80-0.97), respectively.
  
  
  
  This study found a stroke-risk reduction associated with VKA and an increased risk of gastrointestinal bleeding associated with platelet-aggregation inhibitors in comparison with untreated patients. Both antithrombotic groups showed a reduction in all-cause mortality. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Maria
authors.identifier: 0000-0003-3750-9233
authors.initials: M
authors.lastname: Giner-Soriano
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Roso-Llorach
authors.affiliation: Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.|Unitat de farmàcia, Servei d'Atenció Primària Barcelonès Nord i Maresme, Institut Català de la Salut, Badalona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vedia Urgell
authors.affiliation: Translab Research Group, Unitat de Farmacologia Clínica, Departament de Ciències Mèdiques, Facultat de Medicina, UdG, Girona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Castells
authors.affiliation: Translab Research Group, Unitat de Farmacologia Clínica, Departament de Ciències Mèdiques, Facultat de Medicina, UdG, Girona, Spain.
authors.forename: Dolors
authors.initials: D
authors.lastname: Capellà
authors.affiliation: Unidad de Epidemiología del Servicio de Cardiología, Hospital Vall d'Hebron y CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ferreira-González
authors.affiliation: System for the Improvement of Research in Primary Care (SIDIAP), Barcelona, Spain.
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Elorza-Ricart
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Casajuana
authors.affiliation: Unitat de Coordinació i Estratègia del Medicament, Institut Català de la Salut, Barcelona, Spain.
authors.forename: Amelia
authors.initials: A
authors.lastname: Troncoso Mariño
authors.affiliation: Servei de Farmacologia, Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Diògene
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Bolíbar
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Concepció
authors.initials: C
authors.lastname: Violan
authors.affiliation: Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.|Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Morros
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D002543:Cerebral Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D015331:Cohort Studies; D016208:Databases, Factual; D057286:Electronic Health Records; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D011320:Primary Health Care; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013030:Spain; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014812:Vitamin K
keywords: all-cause mortality; antithrombotic; atrial fibrillation; cerebral haemorrhage; electronic health records; gastrointestinal haemorrhage; pharmacoepidemiology; platelet-aggregation inhibitors; primary health care; stroke; vitamin K antagonists