Introduction: With the undisputed benefit of acute endovascular therapy and anticipated extended treatment window among select stroke patients, there is an urgent and unmet need for a regional prehospital decision-making tool to triage patients to centers with endovascular therapy). Existing tools with severity-based triage do not capture important regional variation.
Objectives: To create a model to guide prehospital triage of suspected acute stroke patients.
Methods: We designed a model to estimate the probability of a favorable functional outcome at 90 days when a patient receives acute stroke therapy with either IV thrombolysis (modified Rankin Scale 0-1) or endovascular therapy (modified Rankin Scale 0-2) at stratified time thresholds. We used published pooled patient-level outcomes data with region-specific variables including distribution of door to needle, door to groin, and estimated travel times, as well as time last normal. We created an online tool based on the model for easy use by emergency medical services and other stakeholders in acute stroke care to choose the triage destination with the highest estimated probability of the desired outcome.
Results: Figure 1 illustrates the basic structure of the decision tool from which optimal transportation decisions can be found by applying region specific time data (top) and presents an example plot using hypothetical variables where the model estimates a 36% likelihood of a favorable outcome in a patient who is 75% likely to be eligible for endovascular therapy if triaged to either a primary or comprehensive stroke center (bottom).
Conclusions: This novel decision analysis tool demonstrates that region-specific triage algorithms can be designed for acute stroke care. Future objectives are to validate this decision model in multiple stroke systems. The tool may help guide regional policy decisions on when to bypass a hospital capable of IV thrombolysis for one capable of endovascular therapy.