UMEM Educational Pearls

Category: EMS

Title: Does EMS diversion impact the number of ambulances that arrive at a particular facility?

Keywords: EMS, red, yellow, divert, capacity (PubMed Search)

Posted: 12/20/2023 by Jenny Guyther, MD (Updated: 4/24/2024)
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US hospitals have traditionally been concerned that without an ambulance diversion protocol that they would be overrun with EMS arrivals.  EMS had been concerned that without diversion there would be extended wait times at the hospital.  This study looked at EMS arrivals one year (2021) before the elimination of diversion and compared the number to one year after diversion elimination (2022).  

This study of a single level 1 trauma center showed that there was NO difference between the number of EMS arrivals per day (84 vs 83, p = 0.08), time to room for ESI 2 patients, time to head CT in acute stroke patients OR ambulance turn around time (16 min vs 17 min, p = 0.15).


Aaron M. Burnett, Kari B. Haley, Matthew F. Milder, Bjorn K. Peterson, Joey Duren, Andrew Stevens, Danielle M. Hermes, Paul Nystrom, Joseph Lippert, Jennifer L. Moberg & Kurt M. Isenberger (2023) Elimination of Emergency Department Ambulance Divert during the COVID-19 Pandemic Was Not Associated with an Increase in the Average Number of Ambulance Arrivals per Day, Prehospital Emergency Care, DOI: 10.1080/10903127.2023.2271567