| Active cancer (treatment ongoing, administered within 6 months or palliative) | +1 |
| Paralysis, paresis or recent plaster immobilization of the lower extremities | +1 |
| Recently bedridden for >3 d or major surgery <12 wk | +1 |
| Localized tenderness along the distribution of the deep venous system | +1 |
| Swelling of entire leg | +1 |
| Calf swelling >3 cm larger than asymptomatic side (10cm below tibial tuberosity) | +1 |
| Pitting oedema confined to the symptomatic leg | +1 |
| Collateral superficial veins (nonvaricose) | +1 |
| Previously documented DVT | +1 |
| Alternative diagnosis at least as likely as DVT | -2 |
| High probability (PPV 53%) | >=3 |
| Moderate probability (PPV 17%) | 1 or 2 |
| Low probability (PPV 5%) | <=0 |
Wells PS, Anderson DR, et al.
Excluding pulmonary embolism at the bedside without diagnostic
imaging: Management of patients with suspected pulmonary embolism presenting to the emergency
department by using a simple clinical model and D-dimer.
Annals Intern Med 2001;135:98-107.
Wells PS, Owen C, Doucette S, Fergusson D, Tran H.
Does this patient have deep vein thrombosis?
JAMA. 2006 Jan 11;295(2):199-207.