Prehospital Triage Strategies for the Transportation of Suspected Stroke Patients in the United States.
BACKGROUND AND PURPOSE
Ischemic stroke patients with large vessel occlusion (LVO) could benefit from direct transportation to an intervention center for endovascular treatment, but non-LVO patients need rapid IV thrombolysis in the nearest center. Our aim was to evaluate prehospital triage strategies for suspected stroke patients in the United States.


METHODS
We used a decision tree model and geographic information system to estimate outcome of suspected stroke patients transported by ambulance within 4.5 hours after symptom onset. We compared the following strategies: (1) Always to nearest center, (2) American Heart Association algorithm (ie, directly to intervention center if a prehospital stroke scale suggests LVO and total driving time from scene to intervention center is <30 minutes, provided that the delay would not exclude from thrombolysis), (3) modified algorithms with a maximum additional driving time to the intervention center of <30 minutes, <60 minutes, or without time limit, and (4) always to intervention center. Primary outcome was the annual number of good outcomes, defined as modified Rankin Scale score of 0-2. The preferred strategy was the one that resulted in the best outcomes with an incremental number needed to transport to intervention center (NNTI) <100 to prevent one death or severe disability (modified Rankin Scale score of >2).


RESULTS
Nationwide implementation of the American Heart Association algorithm increased the number of good outcomes by 594 (+1.0%) compared with transportation to the nearest center. The associated number of non-LVO patients transported to the intervention center was 16 714 (NNTI 28). The modified algorithms yielded an increase of 1013 (+1.8%) to 1369 (+2.4%) good outcomes, with a NNTI varying between 28 and 32. The algorithm without time limit was preferred in the majority of states (n=32 [65%]), followed by the algorithm with <60 minutes delay (n=10 [20%]). Tailoring policies at county-level slightly reduced the total number of transportations to the intervention center (NNTI 31).


CONCLUSIONS
Prehospital triage strategies can greatly improve outcomes of the ischemic stroke population in the United States, but increase the number of non-LVO stroke patients transported to an intervention center. The current American Heart Association algorithm is suboptimal as a nationwide policy and should be modified to allow more delay when directly transporting LVO-suspected patients to an intervention center.
['Venema|Esmee|E|', 'Burke|James F|JF|', 'Roozenbeek|Bob|B|', 'Nelson|Jason|J|', 'Lingsma|Hester F|HF|', 'Dippel|Diederik W J|DWJ|', 'Kent|David M|DM|']
D000465:Algorithms D000552:Ambulances D000572:American Heart Association D003663:Decision Trees D004632:Emergency Medical Services D057510:Endovascular Procedures D040362:Geographic Information Systems D006291:Health Policy D006801:Humans D000083242:Ischemic Stroke D010360:Patient Transfer D012720:Severity of Illness Index D017131:Thrombectomy D015912:Thrombolytic Therapy D061665:Time-to-Treatment D014187:Transportation of Patients D014218:Triage D014481:United States
triage ambulances American Heart Association emergency medical services thrombectomy