race_stroke_scale: Rapid Arterial Occlusion Evaluation (RACE) Scale for Stroke

In cliot: Clinical Indices and Outcomes Tools

Rapid Arterial Occlusion Evaluation (RACE) Scale for Stroke

Description

Calculates the RACE Scale score to identify patients with acute stroke who are likely to have a Large Vessel Occlusion (LVO). This prehospital tool assesses 5 distinct neurological domains to help triage patients to the appropriate stroke center for endovascular treatment.

Usage

race_stroke_scale(facial_palsy, arm_motor, leg_motor, head_gaze_deviation,
                  aphasia_or_agnosia)

Arguments

facial_palsy	Numeric (0-2). 0: Absent. 1: Mild (droop). 2: Moderate to Severe (paralysis).
arm_motor	Numeric (0-2). Motor function of the affected arm. 0: Normal to Mild (holds > 10s). 1: Moderate (holds < 10s). 2: Severe (does not raise or creates no effort).
leg_motor	Numeric (0-2). Motor function of the affected leg. 0: Normal to Mild (holds > 5s). 1: Moderate (holds < 5s). 2: Severe (does not raise or creates no effort).
head_gaze_deviation	Numeric (0-1). Head and gaze deviation. 0: Absent. 1: Present (eyes or head deviated to one side).
aphasia_or_agnosia	Numeric (0-2). Assessment of cortical signs based on the side of hemiparesis. If Right Hemiparesis (Left Hemisphere), assess Aphasia (Naming/Orders). If Left Hemiparesis (Right Hemisphere), assess Agnosia (Arm/Anosognosia). 0: Normal. 1: Moderate. 2: Severe.

Value

A list containing:

RACE_Score	The calculated total score (Range 0-9).
Interpretation	Likelihood of LVO (Score >= 5 indicates high probability).
Performance_at_Cutoff_5	Sensitivity and specificity metrics for LVO detection at the threshold of 5.

References

Pérez de la Ossa N, Carrera D, Gorchs M, et al. Design and validation of a prehospital stroke scale to predict large arterial occlusion: the rapid arterial occlusion evaluation scale. Stroke. 2014;45(1):87-91. doi:10.1161/STROKEAHA.113.003071

Examples

# Example 1: High Probability of LVO
# Moderate Face (2), Severe Arm (2), Severe Leg (2), Gaze (1), Severe Aphasia (2)
# Score = 9
race_stroke_scale(2, 2, 2, 1, 2)

# Example 2: Lower Probability
# Mild Face (1), Moderate Arm (1), Normal Leg (0), No Gaze (0), No Agnosia (0)
# Score = 2
race_stroke_scale(1, 1, 0, 0, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.