Wells Score: Probability of Deep Venous Thrombosis Based on Clinical Factors

Factors

Tenderness along distribution of the veins in calf or thigh

Swelling of entire leg

Calf swelling (> 3 cm difference in circumference between calves, measured 10 cm below the tibial tuberosity)

Pitting edema greater in affected leg

Dilated collateral superficial veins

Active cancer (treatment ongoing or given within the previous 6 months)

Immobilization of lower extremity (eg, due to paralysis, paresis, casting, or recent long-distance travel)

Surgery leading to immobility for > 3 days within the past 4 weeks

Previous DVT

Probability

Probability equals the number of factors, subtracting 2 if another diagnosis is as likely as or more likely than deep venous thrombosis.

• High probability: ≥ 3 points

• Moderate probability: 1–2 points

• Low probability: ≤ 0 points