Emergency medical services agency-level variation in non-initiation of resuscitation and termination of resuscitation in out-of-hospital cardiac arrest.

Background

Variations in the decisions to initiate and terminate resuscitation for out-of-hospital cardiac arrest (OHCA) likely differ across emergency medical services (EMS) systems. We evaluated EMS-agency variation in non-initiation of resuscitation for EMS-assessed OHCA and applying termination of resuscitation (TOR) for those meeting the Universal TOR rule.

Methods

We conducted a retrospective cohort study of patients with non-traumatic OHCA using the 2018-2024 ESO Data Collaborative. Our outcomes were non-initiation of resuscitation and TOR. For each outcome, we quantified the extent of agency-level variation using the median odds ratio (MOR), which represents the median increase in odds when comparing similar encounters treated by two randomly selected EMS agencies, calculated from mixed-effects models that incorporated demographic, arrest, scene, agency, and EMS care variables.

Results

Among 560,240 encounters, resuscitation was not initiated in 76,859 (13.7%). Of the 309,048 encounters eligible for the Universal TOR rule, 175,826 (56.9%) underwent TOR. After adjustment for encounter-level factors, the median agency-specific rates were 13.6% (IQR, 11.0%-16.7%) for non-initiation and 54.3% (IQR, 35.5%-67.4%) for TOR. The MOR for non-initiation of resuscitation was 2.30 (95% CI 2.21-2.38), and the MOR for TOR was 4.13 (95% CI 3.87-4.26).

Conclusion

Even after adjustment for measured patient and agency characteristics, we observed substantial between-agency variation in non-initiation of resuscitation and TOR. Findings highlight the need for further evaluation of prehospital decision-making processes and opportunities to identify and reduce unwarranted variation and improve consistency, equity, and quality of prehospital care.