title: Temporal trends in out-of-hospital cardiac arrest survival outcomes between two metropolitan communities: Seoul-Osaka resuscitation study.
abstract: OBJECTIVE
  The objective of this study was to compare the temporal trends in survival after out-of-hospital cardiac arrest (OHCA) between two large metropolitan communities in Asia and evaluate the factors affecting survival after OHCA.
  
  
  METHODS
  A population-based prospective observational study.
  
  
  METHODS
  The Cardiovascular Disease Surveillance (CAVAS) project in Seoul and the Utstein Osaka Project in Osaka.
  
  
  METHODS
  A total of 36,292 resuscitation-attempted OHCAs with cardiac aetiology from 2006 to 2011 in Seoul and Osaka (11,082 in Seoul and 25,210 in Osaka).
  
  
  METHODS
  The primary outcome was neurologically favourable survival. Trend analysis and multivariable Poisson regression models were conducted to evaluate the temporal trends in survival of two communities.
  
  
  RESULTS
  During the study period, the overall neurologically favourable survival was 2.6% in Seoul and 4.6% in Osaka (p<0.01). In both communities, bystander cardiopulmonary resuscitation (CPR) rates increased significantly from 2006 to 2011 (from 0.1% to 13.1% in Seoul and from 33.3% to 41.7% in Osaka). OHCAs that occurred in public places increased in Seoul (12.5% to 20.1%, p for trend <0.01) and decreased in Osaka (13.5% to 10.5%, p for trend <0.01). The proportion of OHCAs defibrillated by emergency medical service (EMS) providers was only 0.4% in 2006 but increased to 17.5% in 2011 in Seoul, whereas the proportion in Osaka decreased from 17.7% to 13.7% (both p for trend <0.01). Age-adjusted and gender-adjusted rates of neurologically favourable survival increased significantly in Seoul from 1.4% in 2006 to 4.3% in 2011 (adjusted rate ratio per year, 1.17; p for trend <0.01), whereas no significant improvement was observed in Osaka (3.6% in 2006 and 5.1% in 2011; adjusted rate ratio per year, 1.03; p for trend=0.08).
  
  
  CONCLUSIONS
  Survivals after OHCA were increased in Seoul while remained constant in Osaka, which may have been affected by the differences and improvements of patient, community, and EMS system factors.
authors.affiliation: Laboratory of Emergency Medical Services, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Ro
authors.affiliation: Department of Emergency Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Shin
authors.affiliation: Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Tetsuhisa
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Emergency Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eui Jung
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kajino
authors.affiliation: Department of Emergency Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyoung Jun
authors.initials: KJ
authors.lastname: Song
authors.affiliation: Department of Pharmacoepidemiology, Kyoto University Graduate School of Medicine and Public Health, Kyoto, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Nishiyama
authors.affiliation: Laboratory of Emergency Medical Services, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kong
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Department of Acute Medicine, Faculty of Medicine, Kinki University, Osaka-Sayama, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishiuchi
authors.affiliation: Senri Critical Care Medical Center, Osaka Saiseikai Senri Hospital, Suita, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Health Service, Kyoto University, Kyoto, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
mesh_terms: D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D009422:Nervous System Diseases / Q000209:etiology; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000453:epidemiology*; D016012:Poisson Distribution; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D066106:Seoul / Q000453:epidemiology; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
keywords: ACCIDENT & EMERGENCY MEDICINE; EPIDEMIOLOGY