Rapid Arterial Occlusion Evaluation Scale Agreement between Emergency Medical Services Technicians and Neurologists

Abstract

Background: Rapid arterial occlusion evaluation (RACE) scale is a valid prehospital tool used to predict large vessel occlusion of major cerebral arteries in patients with suspected acute stroke. RACE scale administered by Emergency medicine services (EMS) technicians in the prehospital setting correlates well with NIH Stroke Scale score after patient arrival at a hospital. Despite this, the RACE scale is often characterized as too difficult for EMS technicians to accurately utilize. There are no data examining RACE scale accuracy in the prehospital setting comparing EMS technicians with neurologists. We sought to examine agreement between RACE scores calculated by EMS technicians and stroke neurologists in the prehospital setting during telestroke consultation.

Methods: Data for this observational cohort study were prospectively collected and retrospectively analyzed. EMS technicians in person and stroke specialized neurologists via televideo connection independently assessed suspected stroke patients and calculated RACE scores in the prehospital setting. We used a linearly weighted Cohen's kappa (k_w) to estimate the extent of agreement for RACE score between EMS technicians and stroke neurologists.

Results: Thirty-one patients with stroke symptoms were independently examined and assessed with the RACE scale by EMS technicians and stroke neurologists in the prehospital setting. Exact agreement on the RACE score was found in 24 of 31 (77%) patients. We found very good agreement between EMS technicians and stroke neurologists, k_w = .818 (95% CI, .677-.960), P< .001.

Conclusions: EMS technicians provide reliable RACE assessments in patients with suspected stroke, with agreement similar to stroke specialized neurologists in the prehospital setting.

Keywords: Emergency medical services; LVO; RACE; diagnosis; prehospital; stroke; thrombectomy; triage.