Regional Variation in Out-of-Hospital Cardiac Arrest Survival in the United States

Circulation. 2016 May 31;133(22):2159-68. doi: 10.1161/CIRCULATIONAHA.115.018175. Epub 2016 Apr 14.


Background: Although previous studies have shown marked variation in out-of-hospital cardiac arrest survival across US regions, factors underlying this survival variation remain incompletely explained.

Methods and results: Using data from the Cardiac Arrest Registry to Enhance Survival, we identified 96 662 adult patients with out-of-hospital cardiac arrest in 132 US counties. We used hierarchical regression models to examine county-level variation in rates of survival and survival with functional recovery (defined as Cerebral Performance Category score of 1 or 2) and examined the contribution of demographics, cardiac arrest characteristics, bystander cardiopulmonary resuscitation, automated external defibrillator use, and county-level sociodemographic factors in survival variation across counties. A total of 9317 (9.6%) patients survived to discharge, and 7176 (7.4%) achieved functional recovery. At a county level, there was marked variation in rates of survival to discharge (range, 3.4%-22.0%; median odds ratio, 1.40; 95% confidence interval, 1.32-1.46) and survival with functional recovery (range, 0.8%-21.0%; median odds ratio, 1.53; 95% confidence interval, 1.43-1.62). County-level rates of bystander cardiopulmonary resuscitation and automated external defibrillator use were positively correlated with both outcomes (P<0.0001 for all). Patient demographic and cardiac arrest characteristics explained 4.8% and 27.7% of the county-level variation in survival, respectively. Additional adjustment of bystander cardiopulmonary resuscitation and automated external defibrillator explained 41% of the survival variation, and this increased to 50.4% after adjustment of county-level sociodemographic factors. Similar findings were noted in analyses of survival with functional recovery.

Conclusions: Although out-of-hospital cardiac arrest survival varies significantly across US counties, a substantial proportion of the variation is attributable to differences in bystander response across communities.

Keywords: cardiopulmonary resuscitation; heart arrest.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Cardiopulmonary Resuscitation / mortality*
  • Databases, Factual
  • Female
  • Humans
  • Male
  • Middle Aged
  • Out-of-Hospital Cardiac Arrest / diagnosis*
  • Out-of-Hospital Cardiac Arrest / mortality*
  • Out-of-Hospital Cardiac Arrest / therapy
  • Registries
  • Survival Rate / trends
  • United States / epidemiology
  • Young Adult