Differences in Out-of-Hospital Cardiac Arrest Management and Outcomes across Urban, Suburban, and Rural Settings.

BACKGROUND: Rural prehospital care settings are underrepresented in the out-of-hospital cardiac arrest (OHCA) literature. This study aimed to describe treatment patterns and the odds of a favorable patient outcome (e.g., return of spontaneous circulation (ROSC) or being presumptively alive at the end of the incident) among rural OHCA patients in the U.S. METHODS: Using the 2018 National Emergency Medical Services Informational System (NEMSIS) dataset, we analyzed OHCA incidents where an emergency medical services (EMS) unit provided cardiopulmonary resuscitation (CPR) and either terminated the resuscitation or completed transport. We excluded traumatic injuries, pediatric patients, and incidents with response time >60 minutes. The primary outcome was ROSC at any time during the EMS incident. The secondary outcome was a binary end-of-event indicator previously described for use in NEMSIS to estimate longer-term outcomes. Multivariable logistic regression was performed for each outcome measure comparing rural, suburban, and urban settings while controlling for key factors. RESULTS: A total of 64,489 OHCA incidents were included, with 5,601 (8.9%) in rural settings. Among the full sample of OHCA incidents, ROSC was achieved in 20,578 (33.6%) cases, including 29.2% in rural settings and 34.1% in urban or suburban settings (p < 0.001). Advanced life support units responded to 95.3% of all calls, and a greater proportion of rural OHCA incidents were managed by basic life support units (7.4% vs. 4.2%, p < 0.001). Rural OHCA incidents had longer response times (7.5 vs. 5.9 minutes, p < 0.001), and rural patients were less likely to receive epinephrine (69.3% vs. 73.3%, p < 0.001). Further, EMS clinicians in rural areas were more likely to use mechanical CPR (29.5% vs. 27.6%, p < 0.01) and were less likely to perform advanced airway management (48.5% vs. 54.2%, p < 0.001). Rural patients had lower odds of achieving ROSC than urban patients after controlling for other factors (OR 0.81, 95% CI: 0.75-0.87). Rural patients also had lower odds of having a positive end-of-event outcome (i.e., presumptively alive) after controlling for other factors (OR 0.86, 95% CI: 0.79-0.93). CONCLUSION: In this national sample of EMS-treated OHCAs, rural patients had lower odds of a favorable outcome (e.g., ROSC or presumptively alive) compared to those in urban settings.