ABCD² Score (stroke risk after TIA)
Two-day ischemic stroke risk after transient ischemic attack.
About this calculator
The ABCD² score estimates 2-day and 7-day stroke risk after transient ischaemic attack. Developed by Johnston et al. (Lancet, 2007) in a cohort of 4809 patients. Points are added across 5 criteria: Age >=60 (1), Blood pressure >=140/90 (1), Clinical features unilateral weakness 2 or speech disturbance without weakness 1, Duration >=60 min (2) or 10-59 min (1), Diabetes (1). Maximum 7 points. Interpretation: 0-3 points – low risk (1% at 2 days, 1.2% at 7 days), outpatient workup within 48 hours. 4-5 points – moderate risk (4.1% at 2 days, 5.9% at 7 days), admission for expedited workup. 6-7 points – high risk (8.1% at 2 days, 11.7% at 7 days), urgent admission to a stroke unit. Where applied. Emergency department, outpatient neurology, primary care – with suspected TIA to guide disposition. AHA/ASA 2021 recommends ABCD² as part of comprehensive assessment, not as the sole admission criterion – patients with atrial fibrillation, symptomatic carotid stenosis, or DWI-positive minor stroke are admitted regardless of score. Limitations. Not used in completed stroke. Does not distinguish vertebrobasilar vs carotid TIA. Does not incorporate neuroimaging – some low-score patients with positive DWI-MRI have risk comparable to the 6-7 group (the ABCD²-I modification).
Source
Formula version: johnston-2007-v1