⚕️ For clinical reference only. Not a substitute for professional judgment.

Wells Score — DVT DVT

Pre-test probability for deep vein thrombosis. Guides D-dimer and proximal vein duplex ultrasound decisions.

Low Probability

Select criteria present.

Clinical Criteria (+1 each)

Active cancer (treatment ongoing or within 6 months)+1 Paralysis, paresis, or recent plaster cast of lower extremity+1 Bedridden >3 days or major surgery within 12 weeks+1 Localised tenderness along deep venous system+1 Entire leg swelling+1 Calf swelling >3 cm compared to asymptomatic leg+1 Pitting oedema (greater in symptomatic leg)+1 Collateral (non-varicose) superficial veins+1

Alternative Diagnosis

Alternative diagnosis at least as likely as DVT−2

Thresholds

≤0 = Low (~5%) → D-dimer; if negative: DVT excluded
1–2 = Moderate (~17%) → D-dimer; if elevated → USS
≥3 = High (~53%) → Proximal vein duplex USS directly

References

Wells PS et al. Lancet. 1997; N Engl J Med. 2003.
NICE CG144. 2020.