Emergency Medical Service Agency Practices and Cardiac Arrest Survival.

Importance: Survival for out-of-hospital cardiac arrest (OHCA) varies widely across emergency medical service (EMS) agencies in the US. However, little is known about which EMS practices are associated with higher agency-level survival.

Objective: To identify resuscitation practices associated with favorable neurological survival for OHCA at EMS agencies.

Design, Setting, And Participants: This cohort study surveyed EMS agencies participating in the Cardiac Arrest Registry to Enhance Survival (CARES) with 10 or more OHCAs annually during January 2015 to December 2019; data analyses were performed from April to October 2023.

Exposure: Survey of resuscitation practices at EMS agencies.

Main Outcomes And Measures: Risk-standardized rates of favorable neurological survival for OHCA at each EMS agency were estimated using hierarchical logistic regression. Multivariable linear regression then examined the association of EMS practices with rates of risk-standardized favorable neurological survival.

Results: Of 577 eligible EMS agencies, 470 agencies (81.5%) completed the survey. The mean (SD) rate of risk-standardized favorable neurological survival was 8.1% (1.8%). A total of 7 EMS practices across 3 domains (training, cardiopulmonary resuscitation [CPR], and transport) were associated with higher rates of risk-standardized favorable neurological survival. EMS agencies with higher favorable neurological survival rates were more likely to use simulation to assess CPR competency (β = 0.54; P = .05), perform frequent reassessment (at least once every 6 months) of CPR competency in new staff (β = 0.51; P = .04), use full multiperson scenario simulation for ongoing skills training (β = 0.48; P = .01), perform simulation training at least every 6 months (β = 0.63; P < .001), and conduct training in the use of mechanical CPR devices at least once annually (β = 0.43; P = .04). EMS agencies with higher risk-standardized favorable neurological survival were also more likely to use CPR feedback devices (β = 0.58; P = .007) and to transport patients to a designated cardiac arrest or ST-segment elevation myocardial infarction receiving center (β = 0.57; P = .003). Adoption of more than half (≥4) of the 7 practices was more common at EMS agencies in the highest quartile of favorable neurological survival rates (70 of 118 agencies [59.3%]) vs the lowest quartile (42 of 118 agencies [35.6%]) (P < .001).

Conclusions And Relevance: In a national registry for OHCA, 7 practices associated with higher rates of favorable neurological survival were identified at EMS agencies. Given wide variability in neurological survival across EMS agencies, these findings provide initial insights into EMS practices associated with top-performing EMS agencies in OHCA survival. Future studies are needed to validate these findings and identify best practices for EMS agencies.