Recent Trends in Survival from Out-of-Hospital Cardiac Arrest in the United States
Background—Despite intensive efforts over many years, the United States has made limited progress in improving rates of survival from out-of-hospital cardiac arrest (OHCA). Recently, national organizations, such as the American Heart Association, have focused on promoting bystander cardiopulmonary resuscitation (CPR), use of automated external defibrillators (AEDs), and other performance improvement efforts.
Methods and Results—Using the Cardiac Arrest Registry to Enhance Survival (CARES), a prospective clinical registry, we identified 70 027 U.S. patients who experienced an OHCA between October 2005 and December 2012. Using multilevel Poisson regression, we examined temporal trends in risk-adjusted survival. After adjusting for patient and cardiac arrest characteristics, risk-adjusted rates of OHCA survival increased from 5.7% in the reference period of 2005-2006 to 7.2% in 2008 (adjusted risk ratio, 1.27; 95% CI, 1.12-1.43; P<0.001). Survival improved more modestly to 8.3% in 2012 (adjusted risk ratio, 1.47; 95% CI, 1.26-1.70; P<0.001). This improvement in survival occurred in both shockable and non-shockable arrest rhythms (P for interaction=0.22) and was also accompanied by better neurological outcomes among survivors (P for trend<0.001). Improved survival was due to both higher rates of pre-hospital survival, where risk-adjusted rates increased from 14.3% in 2005-2006 to 20.8% in 2012 (P for trend<0.001),and in-hospital survival (P for trend=0.015). Rates of bystander CPR and AED use modestly increased during the study period and partly accounted for pre-hospital survival trends.
Conclusions—Data drawn from a large subset of U.S communities suggest that rates of survival from OHCA have improved among sites participating in a performance improvement registry.
- Received February 25, 2014.
- Revision received August 31, 2014.
- Accepted September 11, 2014.