Prehospital FAST-ED Score Item Agreement with Corresponding In-Hospital NIHSS Item Scores.

Objectives: Emergency medical services (EMS) can shorten time to endovascular treatment by transporting large vessel occlusion (LVO) acute ischemic stroke (AIS) patients directly to thrombectomy centers. The standard prehospital strategy for identifying LVO AIS is performing an LVO screen, such as the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), which our county EMS adopted in 2019. We aimed to assess agreement of the FAST-ED score items performed by paramedics in the field with the corresponding National Institutes of Health Stroke Scale (NIHSS) score items obtained by neurologists for patients discharged with an AIS diagnosis.

Methods: We conducted a retrospective study utilizing a prospectively maintained registry of "Code Stroke" patients. We identified patients ≥ 18 years old transported to 1 of 4 hospitals in our system with a FAST-ED score documented. We included patients diagnosed with AIS for whom the Code Stroke protocol was activated and NIHSS recorded in the registry. As each patient was assessed by 1 paramedic from an EMS clinician pool and 1 neurologist from a hospital pool, we measured corresponding item score agreement using unweighted Fleiss Kappa for the dichotomized measure of facial palsy and quadratic Fleiss Kappa for the other ordinal measures.

Results: From September 2019 to March 2024, we identified 829 patients meeting our inclusion criteria. There was substantial agreement between FAST-ED and NIHSS for arm weakness (Kappa = 0.68, 95% confidence interval (CI) 0.63-0.72) and speech changes defined as dysarthria and/or aphasia (Kappa = 0.61, 95% CI 0.56-0.67). Moderate agreement was found for eye deviation (Kappa = 0.60, 95% CI 0.54-0.66) and speech changes not including dysarthria (Kappa = 0.48, 95% CI 0.43-0.54). There was fair agreement for facial palsy (Kappa = 0.25, 95% CI 0.19-0.32) and denial/neglect (Kappa = 0.33, 95% CI 0.26-0.40).

Conclusions: We found a range of agreement for items of FAST-ED prehospital scores to corresponding items of in-hospital NIHSS, including only fair agreement for facial palsy and denial/neglect. Our findings suggest EMS clinicians may benefit from targeted education in assessing denial/neglect and facial palsy, as well as how to score the speech component in cases of isolated dysarthria.