Identifying high-risk geographic areas for cardiac arrest using three methods for cluster analysis.
OBJECTIVE
The objective was to identify high-risk census tracts, defined as those areas that have both a high incidence of out-of-hospital cardiac arrest (OHCA) and a low prevalence of bystander cardiopulmonary resuscitation (CPR), by using three spatial statistical methods.


METHODS
This was a secondary analysis of two prospectively collected registries in the city of Columbus, Ohio. Consecutive adult (≥18 years) OHCA patients, restricted to those of cardiac etiology and treated by emergency medical services (EMS) from April 1, 2004, to April 30, 2009, were studied. Three different spatial analysis methods (Global Empirical Bayes, Local Moran's I, and SaTScan's spatial scan statistic) were used to identify high-risk census tracts.


RESULTS
A total of 4,553 arrests in 200 census tracts occurred during the study period, with 1,632 arrests included in the final sample after exclusions for no resuscitation attempt, noncardiac etiology, etc. The overall incidence for OHCA was 0.70 per 1,000 people for the 6-year study period (SD = ±0.52). Bystander CPR occurred in 20.2% (n = 329), with 10.0% (n = 167) surviving to hospital discharge. Five high-risk census tracts were identified by all three analytic methods.


CONCLUSIONS
The five high-risk census tracts identified may be possible sites for high-yield targeted community-based interventions to improve CPR training and cardiovascular disease education efforts and ultimately improve survival from OHCA.
Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, CO, USA. comilla.sasson@ucdenver.edu
Comilla
C
Sasson
Michael T
MT
Cudnik
Ariann
A
Nassel
Hugh
H
Semple
David J
DJ
Magid
Michael
M
Sayre
David
D
Keseg
Jason S
JS
Haukoos
Craig R
CR
Warden
D001499:Bayes Theorem; D016887:Cardiopulmonary Resuscitation; D019352:Censuses; D016000:Cluster Analysis; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy*; D015995:Prevalence; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D015996:Survival Rate; D014481:United States / Q000453:epidemiology