Introduction: Comprehensive stroke systems of care include routing to the nearest designated stroke center hospital, bypassing non-designated hospitals. Routing protocols are implemented at the state or county level and vary in qualification criteria and determination of destination hospital. We surveyed all counties in the state of California for presence and characteristics of their prehospital stroke routing protocols.

Methods: Each county’s local emergency medical services agency (LEMSA) was queried for the presence of a stroke routing protocol. We reviewed these protocols for method of stroke identification and criteria for patient transport to a stroke center.

Results: Thirty-three LEMSAs serve 58 counties in California with populations ranging from 1,175 to nearly 10 million. Fifteen LEMSAs (45%) had stroke routing protocols, covering 23 counties (40%) and 68% of the state population. Counties with protocols had higher population density (1,500 vs. 140 persons per square mile). In the six counties without designated stroke centers, patients meeting criteria were transported out of county. Stroke identification in the field was achieved using the Cincinnati Prehospital Stroke Screen in 72%, Los Angeles Prehospital Stroke Screen in 7% and a county-specific protocol in 22%.

Conclusion: California EMS prehospital acute stroke routing protocols cover 68% of the state population and vary in characteristics including activation by symptom onset time and destination facility features, reflecting matching of system design to local geographic resources.