title: Registry-based studies of atrial fibrillation from Sweden and Denmark, 2000-2014.
abstract: OBJECTIVE
  We have noticed an increasing number of publications in relation to atrial fibrillation (AF) based on Swedish and Danish health care registries and therefore found it of interest to perform a systematic review of study aims, data sources, exposures, outcomes, journal impact factor, and citation statistics.
  
  
  METHODS
  We searched PubMed from 2000 to 31 December 2014. We included publications which were entirely or partly based on administrative registries and clinical quality databases, and where AF defined the study population or constituted the study exposure or outcome.
  
  
  RESULTS
  Our review returned 1445 studies, of which 173 met the criteria for inclusion in the reviews. We noticed an abundant diversity in study aims, data sources, exposures, and outcome. The annual number of publications increased from 1 to 50. The mean (range) and median journal impact factor in the year of publication was 6.9 (0.8-51.7) and 5.7. The total cumulated number of citations up to the end of 2014 for all 173 publications was 3721, and the mean (range) and median cumulated number of citations per publication was 22.4 (0-250) and 6.0, respectively.
  
  
  CONCLUSIONS
  The number of registry-based studies on AF reported from Sweden and Denmark increased substantially from 2000 to 2014, had a great diversity, were well cited and have added information to the understanding of AF epidemiology.
authors.affiliation: a Department of Medicine , Silkeborg Hospital & Institute of Clinical Medicine, Aarhus University Hospital , Silkeborg , Denmark.|b Cardiovascular Research Centre, Central Regional Hospital , Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Frost
authors.affiliation: a Department of Medicine , Silkeborg Hospital & Institute of Clinical Medicine, Aarhus University Hospital , Silkeborg , Denmark.|b Cardiovascular Research Centre, Central Regional Hospital , Denmark.
authors.forename: Anne Krogh
authors.initials: AK
authors.lastname: Grøndal
authors.affiliation: c Department of Medicine , School of Medicine, Boston University , Boston , MA , USA.|d Department of Epidemiology , School of Public Health, Boston University , Boston , MA , USA.
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
authors.affiliation: e Cardiology Unit, Department of Clinical Sciences , Karolinska Institutet, Danderyd's University Hospital , Stockholm , Sweden.
authors.forename: Leif
authors.initials: L
authors.lastname: Friberg
authors.affiliation: e Cardiology Unit, Department of Clinical Sciences , Karolinska Institutet, Danderyd's University Hospital , Stockholm , Sweden.
authors.forename: Mårten
authors.initials: M
authors.lastname: Rosenqvist
authors.affiliation: f Department of Clinical Epidemiology , Aarhus University Hospital , Aarhus , Denmark.
authors.forename: Søren Paaske
authors.initials: SP
authors.lastname: Johnsen
mesh_terms: D000067575:Administrative Claims, Healthcare / Q000706:statistics & numerical data; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D015706:Bibliometrics; D057225:Data Mining; D016208:Databases, Factual / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D006801:Humans; D055811:Journal Impact Factor; D064887:Observational Studies as Topic / Q000706:statistics & numerical data*; D010506:Periodicals as Topic; D011379:Prognosis; D012042:Registries / Q000706:statistics & numerical data*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: Atrial fibrillation; epidemiology; registries; review