MAGENT

ABCD2 score: how the points are calculated

The ABCD2 score adds up points for five items after a transient ischemic attack (TIA): age 60 or older (1 point), blood pressure of 140/90 mm Hg or higher (1), clinical features (2 for one-sided weakness, 1 for speech trouble without weakness), how long symptoms lasted (2 for 60 minutes or more, 1 for 10–59 minutes), and diabetes (1). The total runs from 0 to 7. A 60-year-old with speech trouble without weakness for 10 minutes, blood pressure 120/80 and no diabetes scores 3.

Not a medical device. Not a diagnosis or dosing recommendation.

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What is the ABCD2 score?

ABCD2 is a point score published by S. Claiborne Johnston, Peter Rothwell and colleagues in The Lancet in 2007. It combined two earlier scores, the California score and the ABCD score, into one. The letters stand for Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes, which is where the "2" comes from.

It's also called the ABCD2 TIA score, the Johnston ABCD2 score, or written ABCD².

This page explains the arithmetic. It doesn't give a cutoff, it doesn't sort totals into risk groups, and it doesn't say what a score means for a particular person.

The ABCD2 formula

ABCD2 = age (0–1) + blood pressure (0–1) + clinical features (0–2)
      + duration (0–2) + diabetes (0–1)
maximum = 7

Exact expression the calculator uses:

ABCD2 = age_ge_60 + blood_pressure + clinical_features + duration + diabetes; age >=60 1; SBP >=140 or DBP >=90 1; none 0 / speech_without_weakness 1 / unilateral_weakness 2; duration <10 0, 10-59 1, >=60 2; diabetes 1; bands 0-3 / 4-5 / 6-7; max 7

What each part means

ItemWhat earns pointsPoints
Age60 or older1
Blood pressureSystolic 140 mm Hg or higher, or diastolic 90 mm Hg or higher1
Clinical featuresOne-sided (unilateral) weakness2
Speech trouble without weakness1
Neither0
Duration60 minutes or more2
10 to 59 minutes1
Under 10 minutes0
DiabetesDiabetes mellitus1

How the score works

  1. Age. 60 or older earns 1 point; 59 earns nothing.
  2. Blood pressure. If either the systolic is 140 or more or the diastolic is 90 or more, add 1 point. You don't add 2 when both are high.
  3. Clinical features. Pick one: unilateral weakness (2), speech trouble without weakness (1), or neither (0). They don't add together.
  4. Duration. Under 10 minutes is 0, 10 to 59 minutes is 1, and 60 minutes or more is 2.
  5. Diabetes. Add 1 point if present.
  6. Add them up. The total is 0 to 7.

Inputs and units

Blood pressure is in mm Hg and duration is in whole minutes. Magent's calculator takes age 18 to 120, systolic 50 to 250, diastolic 20 to 160 (it must be lower than the systolic), and duration 0 to 1,440 minutes. Clinical features is one of three choices: none, speech_without_weakness, or unilateral_weakness. The calculator returns the total, the maximum of 7, and a line for each item. It also returns a group label for the total; this page doesn't describe those groups.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: no items

  1. Age 55 → 0; blood pressure 120/80 → 0; no clinical features → 0; 5 minutes → 0; no diabetes → 0.
  2. Score = 0.

Example 2: speech trouble for 10 minutes at 60

  1. Age 60 → 1; blood pressure 120/80 → 0.
  2. Speech trouble without weakness → 1; 10 minutes → 1; no diabetes → 0.
  3. Score = 3.

Example 3: same, with diabetes

  1. As example 2, plus diabetes → 1.
  2. Score = 4.

Example 4: speech trouble for an hour with high systolic pressure

  1. Age 60 → 1; systolic 140 → 1.
  2. Speech trouble without weakness → 1; 60 minutes → 2; no diabetes → 0.
  3. Score = 5.

Example 5: every item at its highest

  1. Age 60 → 1; blood pressure 140/90 → 1.
  2. Unilateral weakness → 2; 60 minutes → 2; diabetes → 1.
  3. Score = 7, the maximum.

ABCD2 edge values

These are Magent's expected values for the calculator. Each changes one item from a baseline of age 55, blood pressure 120/80, 5 minutes, and no clinical features or diabetes. The baseline scores 0, and age 59 still scores 0; age 60 scores 1. Systolic 140 or diastolic 90 scores 1, and blood pressure 139/89 scores 0. Speech trouble without weakness scores 1 and unilateral weakness scores 2. A duration of 9 minutes scores 0, 10 or 59 minutes scores 1, and 60 minutes scores 2. Diabetes scores 1.

History of the ABCD2 score

The score comes from S. Claiborne Johnston, Peter M. Rothwell, Mai N. Nguyen-Huynh and colleagues, Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack, The Lancet 2007 (volume 369, issue 9558, pages 283–292).

The abstract describes testing two existing scores, the California score and the ABCD score, in four independent groups of patients (2,893 people) diagnosed with TIA in emergency departments and clinics in the USA and UK. The two groups used to build the original scores (1,916 people) were then used to derive a unified score with five factors. That unified score is ABCD2.

When it's used

The 2007 abstract says the unified score was designed for prediction of 2-day stroke risk after a TIA. The record describes it as a score for very early stroke risk after TIA.

Where it's used

The patients in the 2007 paper were seen in emergency departments and clinics, in defined populations in the USA and the UK.

Who uses it

The record says the clinical features item is chosen by the person using the calculator. Magent's calculator doesn't examine anyone or decide whether an episode was a TIA.

Limits of the calculation

  • It adds up five items. It doesn't diagnose a TIA or a stroke.
  • It's ABCD2 (Johnston 2007), not the older ABCD score and not ABCD3-I.
  • Clinical features is one choice, picked by the user. Weakness and speech trouble don't add together.
  • Blood pressure scores 1 point at most, whichever number is high.
  • This page doesn't say what to do with a score.

Clinical decisions belong to a qualified clinician who knows the patient.

  • Glasgow Coma Scale adds eye, verbal and motor responses into a total. It measures level of consciousness rather than features of a TIA.

Glossary

  • TIA (transient ischemic attack): a brief episode of stroke-like symptoms that resolve.
  • Unilateral weakness: weakness on one side of the body.
  • Systolic / diastolic: the top and bottom numbers of a blood pressure reading.
  • mm Hg: millimeters of mercury, the unit for blood pressure.

Common mistakes

  • Adding both clinical features. Pick the higher one that applies; weakness is 2 even if speech is also affected.
  • Giving 2 points for blood pressure. It's 1 point if either number is high.
  • Counting 59 minutes as an hour. Duration 59 is 1 point; 60 is 2.
  • Confusing ABCD2 with ABCD. ABCD2 adds diabetes; the maximum is 7.

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. DOI: 10.1016/S0140-6736(07)60150-0

Frequently asked questions

How do you calculate the ABCD2 score?

Add 1 for age 60 or older, 1 for blood pressure 140/90 or higher, 2 for unilateral weakness or 1 for speech trouble without weakness, 2 for symptoms lasting 60 minutes or more or 1 for 10–59 minutes, and 1 for diabetes. The total is 0 to 7.

What ABCD2 score is high risk?

This page doesn't give a cutoff or sort scores into risk groups. It adds up the points; what a score means depends on the person and the clinical context.

What does ABCD2 stand for?

Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes. The 2 marks the two D's.

What is the highest ABCD2 score?

7, with every item at its highest value.

Do speech trouble and weakness add together?

No. Unilateral weakness scores 2. Speech trouble scores 1 when there's no weakness.

Who developed the ABCD2 score?

S. Claiborne Johnston, Peter Rothwell and colleagues, in a 2007 Lancet paper.