Background: The Resuscitation Outcomes Consortium (ROC) maintains an epidemiological registry (Epistry) of out-of-hospital cardiac arrest (OHCA), providing an opportunity to assess temporal trends in OHCA incidence, treatment and outcomes.
Methods: Patient, event, system, treatment, and outcome data from adult (≥18 years) OHCA from July 1, 2011 to June 30, 2015 entered into Epistry were analyzed to identify overall and site-level trends. We used descriptive statistics to characterize the sample and logistic regression to assess the impact of year as well as key covariates associated with survival. Incidence data was examined for three complete calendar years, 2012 to 2014.
Results: During the four-year study period, 85,553 patients were assessed by Emergency Medical Services (EMS) and 45,516 (53.2%, site range 30.4% to 69.9%) had resuscitation attempted. The incidence of both EMS-assessed and treated OHCA increased over time (p<0.01 and p=0.01, respectively). Most patient and event characteristics were consistent except for increases in AED application (3.9% to 5.2%) and bystander CPR (41.3% to 44.9%). EMS CPR depth and compression fraction increased while pre-shock pause interval decreased. Targeted temperature management (TTM) was used in 51.1% of admitted patients and early coronary angiography (first 24 hours) was performed in 30.2%. Survival to hospital discharge increased from 10.9% in year 1 to 11.3% in year 4 with year significantly associated with survival (p<0.001) and an increasing trend over the study period (p=0.02). Site variation in survival was present between and across years (site range: 4.2% to 19.8%). Patients with an initially shockable rhythm (VT/VF) had an overall survival of 32.2% (site range: 11.9%-47.1%) while survival in bystander witnessed VT/VF was 35.8% (site range: 12.9%-53.1%). For survivors with a Modified Rankin Score (MRS) available, most (80.5%) had good neurological function defined as a MRS of ≤ 3.
Conclusions: Survival from adult OHCA in ROC improved from 2011 to 2015 and most survivors had good neurological function. Selected public, EMS, and hospital processes of care have improved over time but marked site differences in survival persist. Reducing variation is essential to improve outcomes from adult OHCA.