What are Wells score or criteria?

In 2006, Scarvelis and Wells overviewed a set of clinical criteria for DVT,^[1] on the heels of a widely adopted set of clinical criteria for pulmonary embolism.^[2][3]

Wells score or criteria: (Possible score -2 to 9)

1) Active cancer (treatment within last 6 months or palliative) -- 1 point

2) Calf swelling >3cm compared to other calf (measured 10cm below tibial tuberosity) -- 1 point

3) Collateral superficial veins (non-varicose) -- 1 point

4) Pitting edema (confined to symptomatic leg) -- 1 point

5) Swelling of entire leg - 1 point

6) Localized pain along distribution of deep venous system -- 1 point

7) Paralysis, paresis, or recent cast immobilization of lower extremities -- 1 point

8) Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 12 weeks -- 1 point

9) Previously documented DVT -- 1 point

10) Alternative diagnosis at least as likely -- Subtract 2 points

Interpretation:

Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.

Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as d-dimer test to further rule out deep vein thrombosis.

http://en.wikipedia.org/wiki/Deep_vein_thrombosis