ABCD²
TIA Stroke Risk (ABCD² Score)
0-3 low · 4-5 moderate · 6-7 high risk of stroke within 2 days.
On the AANP exam, a TIA vignette almost always asks who needs admission and who can be worked up as an outpatient. ABCD2 is the bedside score that answers that question: Age 60+, BP 140/90 or higher, Clinical features (unilateral weakness vs. speech only), Duration (10-59 min vs. 60+), and Diabetes. Total 0-3 is low risk, 4-5 moderate, 6-7 high — the cutoff for hospitalization at most institutions. The score does not change the workup itself, only its tempo. FNP candidates should be able to compute it from a vignette and recite the 2-day stroke risk window.
- AAge ≥60+1 point.
- BBlood pressure ≥140/90 at presentation+1 point.
- CClinical features+2 unilateral weakness; +1 speech disturbance without weakness; 0 other.
- DDuration of symptoms+2 if ≥60 min; +1 if 10-59 min; 0 if <10 min.
- DDiabetes+1 point.
Clinical Context
Estimates 2-day stroke risk after TIA. Low (0-3) ~1%, moderate (4-5) ~4%, high (6-7) ~8%. Any TIA warrants urgent workup regardless of score — ABCD² helps triage disposition speed, not whether to work up.
Guidelines now recommend hospital admission or rapid (<24 hr) TIA clinic evaluation for any ABCD² ≥4 or crescendo TIA. Core workup: non-contrast CT or MRI, carotid imaging (duplex, CTA, or MRA), ECG ± telemetry for A-fib, echo if cardioembolic source suspected, lipid panel, HbA1c. Start antiplatelet (aspirin ± clopidogrel dual therapy for 21-90 days) and statin immediately.
AANP primary-care trap: a patient who had 20 minutes of arm weakness yesterday, resolved — still a TIA, still needs urgent workup, not a "watch and wait."
Related Mnemonics
- AEIOU-TIPS — Causes of Altered Mental Status
- BE FAST — Stroke Recognition (Extended)
- CAM — Delirium Diagnosis (Confusion Assessment Method)
- FAST — Stroke Recognition
- Mini-Cog — Brief Cognitive Screen (Geriatric)
Sources
Ready to practice?
1,500+ AANP-style questions with rationales — free trial.