Background: We sought to characterize changes in the frequency of secondary transfer of EMS-transported stroke patients within a large urban stroke system of care. We hypothesized an increase in secondary stroke transfers given the recent emphasis on thrombectomy treatment.
Methods: Los Angeles County Emergency Medical Services Agency (LAC-EMS) operates a regional stroke system of care with transport of patients with suspected acute stroke identified by EMS in the field to the closest ASC. Current ASC designation does not distinguish primary from comprehensive stroke centers. Each ASC provides data on patient characteristics, treatment, outcome, and final disposition to LAC-EMS. We identified all cases of secondary transfer out of the primary receiving emergency department over a 5-year period (2012 to 2016).
Results: Among 23,586 EMS transports, there were 943 transfers to another acute care hospital. Transferred patients had a mean age of 66 (SD 16) and were 49% female, 59% White race, and 27% Hispanic ethnicity. Final diagnoses were cerebral ischemia (62%), intracerebral hemorrhage (19%), subarachnoid hemorrhage (14%), and non-stroke diagnosis (5%). The median initial NIHSS was 16 (IQR 9-23) and 50% of patients with cerebral ischemia were treated with intravenous thrombolytic therapy. The reason for transfer was higher level of care in 98% and not reported in 2%. The figure shows the annual trends by diagnosis. The total number of transfers increased steadily from 91 in 2012 to 296 in 2016, with the proportion of transfers for cerebral ischemia increasing in 2015-2016 compared to the prior years (68% vs. 55%).
Conclusions: Secondary transfer of EMS-triaged stroke patients increased from 2012 to 2016, particularly for cerebral ischemia in the last 2 years of observation. The higher frequency of ischemic stroke secondary transfers may reflect increased utilization of thrombectomy following publication of positive clinical trial data starting on 12/17/2014.