title: Multiple cluster analysis for the identification of high-risk census tracts for out-of-hospital cardiac arrest (OHCA) in Denver, Colorado.
abstract: BACKGROUND
  Prior research has shown that high-risk census tracts for out-of-hospital cardiac arrest (OHCA) can be identified. High-risk neighborhoods are defined as having a high incidence of OHCA and a low prevalence of bystander cardiopulmonary resuscitation (CPR). However, there is no consensus regarding the process for identifying high-risk neighborhoods.
  
  
  OBJECTIVE
  We propose a novel summary approach to identify high-risk neighborhoods through three separate spatial analysis methods: Empirical Bayes (EB), Local Moran's I (LISA), and Getis Ord Gi* (Gi*) in Denver, Colorado.
  
  
  METHODS
  We conducted a secondary analysis of prospectively collected Emergency Medical Services data of OHCA from January 1, 2009 to December 31, 2011 from the City and County of Denver, Colorado. OHCA incidents were restricted to those of cardiac etiology in adults ≥18 years. The OHCA incident locations were geocoded using Centrus. EB smoothed incidence rates were calculated for OHCA using Geoda and LISA and Gi* calculated using ArcGIS 10.
  
  
  RESULTS
  A total of 1102 arrests in 142 census tracts occurred during the study period, with 887 arrests included in the final sample. Maps of clusters of high OHCA incidence were overlaid with maps identifying census tracts in the below the Denver County mean for bystander CPR prevalence. Five census tracts identified were designated as Tier 1 high-risk tracts, while an additional 7 census tracts where designated as Tier 2 high-risk tracts.
  
  
  CONCLUSIONS
  This is the first study to use these three spatial cluster analysis methods for the detection of high-risk census tracts. These census tracts are possible sites for targeted community-based interventions to improve both cardiovascular health education and CPR training.
authors.affiliation: University of Alabama, Birmingham, AL, United States.
authors.forename: Ariann F
authors.initials: AF
authors.lastname: Nassel
authors.affiliation: University of Colorado, Boulder, CO, United States.
authors.forename: Elisabeth D
authors.initials: ED
authors.lastname: Root
authors.affiliation: Department of Emergency Medicine, University of Colorado, Aurora, CO, United States; Denver Health and Hospital Authority, Denver, CO, United States; Colorado School of Public Health, Aurora, CO, United States.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Haukoos
authors.affiliation: Department of Emergency Medicine, University of Colorado, Aurora, CO, United States; Denver Health and Hospital Authority, Denver, CO, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: McVaney
authors.affiliation: Department of Emergency Medicine, University of Colorado, Aurora, CO, United States; Denver Health and Hospital Authority, Denver, CO, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Colwell
authors.affiliation: Denver Health and Hospital Authority, Denver, CO, United States.
authors.forename: James
authors.initials: J
authors.lastname: Robinson
authors.affiliation: American Heart Association, Dallas, TX, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Eigel
authors.affiliation: Kaiser Permanente, Denver, CO, United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Magid
authors.affiliation: Department of Emergency Medicine, University of Colorado, Aurora, CO, United States; Colorado School of Public Health, Aurora, CO, United States; American Heart Association, Dallas, TX, United States. Electronic address: comilla.sasson@ucdenver.edu.
authors.forename: Comilla
authors.initials: C
authors.lastname: Sasson
mesh_terms: D001499:Bayes Theorem; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D019352:Censuses; D016000:Cluster Analysis; D003120:Colorado / Q000453:epidemiology; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology* / Q000628:therapy; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D014505:Urban Population
keywords: Cardiopulmonary resuscitation; Geographic information systems; Out-of-hospital cardiac arrest; Public health interventions; Spatial statistics