title: Usefulness of a healthcare database for epidemiological research in atrial fibrillation.
abstract: BACKGROUND
  Big data are gaining attention as a valuable resource for providing insights into a range of issues and questions in healthcare. We evaluated the capacity of a Japanese healthcare database to conduct epidemiological research in non-valvular atrial fibrillation (NVAF).
  
  
  RESULTS
  We examined data collected between April 2008 and September 2013 in a Japanese healthcare database. Prior to the risk factor analysis, we validated the criteria for defining the occurrence of a stroke, systemic embolic event (SEE), and intracranial bleeding event during the study period. The validity was considered appropriate based on the resulting high positive predictive values. The data of 18,998 NVAF patients demonstrated that the incidence rates of stroke, SEE, and any bleeding events were 2.2, 0.08, and 2.4 per 100 patient-years, respectively. In patients who had not been treated with an anticoagulant, incidence of stroke significantly increased in higher CHADS2or CHA2DS2-VASc score, 1.7 and 1.5 fold by 1 point increase, respectively. The use of a proton pump inhibitor (PPI) was also identified as an independent risk factor for stroke. In patients who had been treated with an anticoagulant, the independent risk factors for any bleeding events were hypertension, renal dysfunction, hepatic failure, medical history of stroke, older age (≥65 years), use of nonsteroidal anti-inflammatory drug, and PPIs.
  
  
  CONCLUSIONS
  The data obtained in this study were comparable with results obtained in prospective cohort studies conducted in Japan.
authors.affiliation: National Hospital Organization, Osaka National Hospital, Osaka, Japan. Electronic address: koretune@onh.go.jp.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Koretsune
authors.affiliation: The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: Department of Cerebrovascular Medicine and Neurology, National Hospital Organization, Kyushu Medical Center, Fukuoka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yasaka
authors.affiliation: Medical TOUKEI Corporation, Tokyo, Japan.
authors.forename: Eisei
authors.initials: E
authors.lastname: Oda
authors.affiliation: Medical Data Vision Co Ltd., Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsubayashi
authors.affiliation: Medical Data Vision Co Ltd., Tokyo, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Ota
authors.affiliation: Department of Corporate Planning, Linical Co Ltd., Osaka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: EU Biostatistics & Data Management, Daiichi Sankyo Europe GmbH, Munich, Germany.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: Medical Science Department, Daiichi Sankyo Co Ltd., Tokyo, Japan.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Kaburagi
authors.affiliation: Medical Science Department, Daiichi Sankyo Co Ltd., Tokyo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ibusuki
authors.affiliation: Safety and Risk Management Department, Daiichi Sankyo Co Ltd., Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takita
authors.affiliation: Medical Science Department, Daiichi Sankyo Co Ltd., Tokyo, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Iwashita
authors.affiliation: Division of Biostatistics, Tohoku University Graduate School of Medicine, Miyagi, Japan.
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000627:therapeutic use; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000453:epidemiology*; D016208:Databases, Factual; D004812:Epidemiologic Methods; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007674:Kidney Diseases / Q000453:epidemiology; D008107:Liver Diseases / Q000453:epidemiology; D008297:Male; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012106:Research; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D054328:Proton Pump Inhibitors
keywords: Bleeding event; Healthcare database; Non-valvular atrial fibrillation; Stroke; Validation