title: Spatial Variation and Resuscitation Process Affecting Survival after Out-of-Hospital Cardiac Arrests (OHCA).
abstract: BACKGROUND
  Ambulance response times and resuscitation efforts are critical predictors of the survival rate after out-of-hospital cardiac arrests (OHCA). On the other hand, rural-urban differences in the OHCA survival rates are an important public health issue.
  
  
  METHODS
  We retrospectively reviewed the January 2011-December 2013 OHCA registry data of Kaohsiung City, Taiwan. With particular focus on geospatial variables, we aimed to unveil risk factors predicting the overall OHCA survival until hospital admission. Spatial analysis, network analysis, and the Kriging method by using geographic information systems were applied to analyze spatial variations and calculate the transport distance. Logistic regression was used to identify the risk factors for OHCA survival.
  
  
  RESULTS
  Among the 4,957 patients, the overall OHCA survival to hospital admission was 16.5%. In the multivariate analysis, female sex (adjusted odds ratio:, AOR, 1.24 [1.06-1.45]), events in public areas (AOR: 1.30 [1.05-1.61]), exposure to automated external defibrillator (AED) shock (AOR: 1.70 [1.30-2.23]), use of laryngeal mask airway (LMA) (AOR: 1.35 [1.16-1.58]), non-trauma patients (AOR: 1.41 [1.04-1.90]), ambulance bypassed the closest hospital (AOR: 1.28 [1.07-1.53]), and OHCA within the high population density areas (AOR: 1.89 [1.55-2.32]) were positively associated with improved OHCA survival. By contrast, a prolonged total emergency medical services (EMS) time interval was negatively associated with OHCA survival (AOR: 0.98 [0.96-0.99]).
  
  
  CONCLUSIONS
  Resuscitative efforts, such as AED or LMA use, and a short total EMS time interval improved OHCA outcomes in emergency departments. The spatial heterogeneity of emergency medical resources between rural and urban areas might affect survival rate.
authors.affiliation: Center for Geographic Information Science, Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan.
authors.forename: Chien-Chou
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Division of Trauma, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.|Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chao-Wen
authors.initials: CW
authors.lastname: Chen
authors.affiliation: Department of Health, Kaohsiung City Government, Kaohsiung, Taiwan.
authors.forename: Chi-Kung
authors.initials: CK
authors.lastname: Ho
authors.affiliation: Fire Bureau, Kaohsiung City Government, Kaohsiung, Taiwan.
authors.forename: I-Chuan
authors.initials: IC
authors.lastname: Liu
authors.affiliation: Center for Geographic Information Science, Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan.
authors.forename: Bo-Cheng
authors.initials: BC
authors.lastname: Lin
authors.affiliation: Center for Geographic Information Science, Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan.
authors.forename: Ta-Chien
authors.initials: TC
authors.lastname: Chan
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation; D015331:Cohort Studies; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology