RACE scale
Prehospital screen for large-vessel occlusion in suspected stroke
- Derived in Catalonia, Spain (Codi Ictus)
Sources last checked: 2026-10-13
RACE scale
Prehospital screen for large-vessel occlusion in suspected stroke
A triage aid for transport decisions, not a diagnosis: about 6 in 10 patients with RACE ≥ 5 had no LVO in the validation cohort. It does not exclude haemorrhage or stroke mimics.
Interpretation
| 0–4 — LVO less likely | Below the derivation cut-off; a score below 5 does not exclude stroke or large-vessel occlusion. |
|---|---|
| 5–9 — LVO suspected | RACE ≥ 5: sensitivity 0.85, specificity 0.68, PPV 0.42, NPV 0.94 for large-vessel occlusion (prospective validation). |
What is the RACE scale?
The RACE (Rapid Arterial oCclusion Evaluation) scale is a 0–9 prehospital score built from five NIHSS-derived items to identify suspected large-vessel occlusion. Pérez de la Ossa and colleagues designed it in Catalonia, Spain, and validated it prospectively with emergency medical technicians in 2014. It is used in the Catalan stroke code to guide transport to thrombectomy-capable centres.
When to use it
- Prehospital assessment of suspected acute stroke by emergency medical services.
- Background for the transport question between the nearest stroke unit and a thrombectomy-capable centre, as framed in the Catalan stroke code.
- Rapid triage in the emergency department before the full NIHSS.
When not to use it
- To decide whether a stroke code is activated at all — a low RACE does not exclude stroke.
- As a substitute for vascular imaging or for the NIHSS in hospital.
- In posterior-circulation presentations, which the items capture poorly.
How it is calculated
| Criterion | Points |
|---|---|
| Facial palsy (show teeth / smile) | |
| Absent — symmetrical | 0 |
| Mild — slightly asymmetrical | 1 |
| Moderate to severe — completely asymmetrical | 2 |
| Arm motor function (90° sitting / 45° supine) | |
| Normal to mild — holds both arms > 10 s | 0 |
| Moderate — either arm held < 10 s | 1 |
| Severe — cannot raise an arm against gravity | 2 |
| Leg motor function (30° supine) | |
| Normal to mild — holds each leg > 5 s | 0 |
| Moderate — either leg held < 5 s | 1 |
| Severe — cannot raise a leg against gravity | 2 |
| Head and gaze deviation | |
| Absent — eyes move to both sides | 0 |
| Present — eyes and/or head deviated to one side | 1 |
| Aphasia (right hemiparesis) or agnosia (left hemiparesis) | |
| Normal — performs both tasks / no agnosia | 0 |
| Moderate — one task / asomatognosia or anosognosia | 1 |
| Severe — neither task / both asomatognosia and anosognosia | 2 |
Clinical pearls and limitations
- A triage aid for transport decisions, not a diagnosis: about 6 in 10 patients with RACE ≥ 5 had no LVO in the validation cohort. It does not exclude haemorrhage or stroke mimics.
- Score the aphasia item for right hemiparesis and the agnosia item for left hemiparesis — never both.
- RACE ≥ 5 had sensitivity 0.85 and specificity 0.68 for LVO; most positive patients still had no occlusion.
- In the RACECAT trial (Catalonia), direct transport of RACE-positive patients to a thrombectomy centre did not improve 90-day outcome over transport to the nearest stroke centre.
- Head and gaze deviation scores 1 for any persistent deviation to one side.
Frequently asked questions
What RACE score suggests a large-vessel occlusion?
A score of 5 or more, the cut-off from the 2014 validation study.
Is RACE better than the NIHSS?
Its accuracy for LVO was similar to the full NIHSS (AUC 0.82 vs 0.85) while being much faster to perform in the field.
Who can use the RACE scale?
It was validated with trained emergency medical technicians; it is designed for paramedics and emergency teams.
Evidence and guidelines
- Primary source: 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.
- Pérez de la Ossa N et al. (RACECAT). Effect of direct transportation to thrombectomy-capable center vs local stroke center on neurological outcomes in patients with suspected large-vessel occlusion stroke in nonurban areas. JAMA 2022;327(18):1782-1794.
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