August 4, 2020
Use of RACE Scale for Stroke Triage in the United States Validated in Study of EMS Personnel
August 4, 2020—The Society of NeuroInterventional Surgery (SNIS) announced that a new study serves as the first prospective validation of the Rapid Arterial Occlusion Evaluation (RACE) scale to accurately identify a large vessel occlusion (LVO) stroke by United States–based emergency medical services (EMS) personnel in a prehospital setting.
The study, “A Prospective, Multicentered, EMS-Administered, Pre-Hospital Validation Study of the Rapid Arterial Occlusion Evaluation (RACE) Scale for Detecting Large Vessel Occlusion Stroke in the United States Compared to the Original RACE Validation Study from Spain: A Subanalysis of the PREDICT Study,” was presented at the SNIS 17th annual meeting held virtually August 4-7.
According to SNIS, the investigators evaluated 232 adult patients who were suspected by the EMS team of having a stroke and were transported to a participating comprehensive stroke center. All patients had the RACE scale administered prospectively, and their results were recorded in a secure web-based database.
The RACE scale was previously validated by EMS in Spain for accurately identifying this type of life-threatening condition and has been widely adopted in the United States. The health care infrastructure and EMS systems differ significantly between the two countries, and the validity of the results from the Spanish study when applied to the United States systems was untested before this study.
“Standardizing triage protocols is critical for improving stroke systems of care and improving outcomes for patients,” commented Robert F. James, MD, who is the senior author of the study. “The findings of this study advance the validity of the RACE scale, which will help EMS determine stroke severity in the field and ensure that patients receive proper care as soon as possible.” Dr. James is Professor and Vice Chair, Department of Neurosurgery at Indiana University School of Medicine in Indianapolis, Indiana.
As detailed in the study abstract published in the Journal of NeuroInterventional Surgery SNIS meeting supplement, cerebrovascular imaging studies (CTA, MRA, digital subtraction angiography) were reviewed by a blinded, independent neuroradiologist to determine LVO diagnosis.
The investigators used SAS and C statistics to create receiver operating characteristic curves to determine the area under the curve and optimal cut point (CP) scores for the RACE scale. They also calculated the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for the optimal CP score.
As reported in the SNIS abstract:
- The predictive capability of the RACE scale showed similar predictive capacities for radiographically confirmed LVO in patients prospectively tested in the United States as compared with the original Spanish RACE scale population.
- The best CP score value predictive of LVO in the United States RACE study was determined to be ≥ 6, compared to the original Spanish study, which was ≥ 5.
- The overall prevalence of LVO as defined in the United States RACE was 13.4% compared to a prevalence of 21.3% for the original paper‘s definition of LVO.