ABCD² score

Q: Is ABCD² still recommended?

Not for triage. NICE NG128 recommends against it and ESO advises against using it alone. ESO still uses ABCD² ≥ 4 as one marker of high-risk TIA when considering dual antiplatelet therapy.

Q: What does a score of 4 mean?

In the 2007 validation cohorts, scores of 4–5 carried a 2-day stroke risk of about 4 %. It is a population average, not an individual prediction.

Q: Does ABCD² apply to amaurosis fugax?

Transient monocular blindness scores 0 for clinical features, so the score likely underestimates risk in retinal TIA with carotid disease.

Early stroke risk after transient ischaemic attack (TIA)

ESO 2021 TIA: ABCD² ≥ 4 defines high risk for DAPT

Sources last checked: 2026-10-13

ABCD² score

Early stroke risk after transient ischaemic attack (TIA)

Age ≥ 60 years+1Blood pressure ≥ 140/90 mmHg at first assessment+1

Clinical features

Duration of symptoms

Diabetes+1

Fill in every field to see the result.

Not a triage tool: NICE NG128 (2019) advises against using ABCD² to judge stroke risk or referral urgency, and ESO (2021) recommends against using it alone. NICE NG128 provides for specialist assessment within 24 h for every suspected TIA.

Source: Johnston SC, Rothwell PM, Nguyen-Huynh MN et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet 2007;369(9558):283-292.Open

Interpretation

0–3 — low	2-day stroke risk ≈ 1.0 % in the validation cohorts (Johnston 2007).
4–5 — moderate	2-day stroke risk ≈ 4.1 %.
6–7 — high	2-day stroke risk ≈ 8.1 %.

What is the ABCD² score?

ABCD² estimates the short-term risk of stroke after a transient ischaemic attack from age, blood pressure, clinical features, duration and diabetes (0–7 points). Johnston, Rothwell and colleagues unified the earlier California and ABCD scores in 2007, validating it in UK and US cohorts of almost 5000 patients. It predicts 2-day stroke risk, but its sensitivity is too low to triage patients safely.

When to use it

Describing the risk profile of a TIA in research or audit.
Applying ESO 2021 criteria for short-term dual antiplatelet therapy in non-cardioembolic high-risk TIA (ABCD² ≥ 4).
Teaching the clinical features that carry the highest early stroke risk.

When not to use it

To decide how urgently a suspected TIA is seen — NICE NG128 advises against it and recommends specialist review within 24 hours for all.
To reassure a patient with a low score: scores of 0–3 include patients with atrial fibrillation, carotid stenosis or DWI lesions, who carry a high early stroke risk.
In completed stroke or persisting deficits.

How it is calculated

Criterion	Points
Age ≥ 60 years	+1
Blood pressure ≥ 140/90 mmHg at first assessment	+1
Clinical features
Other symptoms	0
Speech disturbance without weakness	1
Unilateral weakness	2
Duration of symptoms
< 10 min	0
10–59 min	1
≥ 60 min	2
Diabetes	+1

Clinical pearls and limitations

Not a triage tool: NICE NG128 (2019) advises against using ABCD² to judge stroke risk or referral urgency, and ESO (2021) recommends against using it alone. NICE NG128 provides for specialist assessment within 24 h for every suspected TIA.
ESO (2021) recommends against using ABCD² alone for triage or treatment decisions; NICE NG128 (2019) says not to use scoring systems such as ABCD² at all for risk or referral urgency.
Imaging (DWI lesion) and vessel findings (ipsilateral stenosis) predict early recurrence independently of the score.
Blood pressure is the first value measured after the event, not a later reading.
Duration counts symptoms, not time to presentation.

Frequently asked questions

Is ABCD² still recommended?

Not for triage. NICE NG128 recommends against it and ESO advises against using it alone. ESO still uses ABCD² ≥ 4 as one marker of high-risk TIA when considering dual antiplatelet therapy.

What does a score of 4 mean?

In the 2007 validation cohorts, scores of 4–5 carried a 2-day stroke risk of about 4 %. It is a population average, not an individual prediction.

Does ABCD² apply to amaurosis fugax?

Transient monocular blindness scores 0 for clinical features, so the score likely underestimates risk in retinal TIA with carotid disease.

Evidence and guidelines

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