How to use it
- Choose DVT for a suspected leg clot or PE for a suspected lung clot.
- Tick each finding that applies; the points are shown at the end of each line.
- Read the Wells score, the two-level result and the three-level probability.
How the scores work
DVT: one point each for active cancer, paralysis or a leg cast, being bedridden or recent major surgery, deep vein tenderness, a swollen whole leg, a calf more than 3 cm larger, pitting oedema in that leg, collateral superficial veins and a previous DVT; −2 if another diagnosis is at least as likely.
- Two levels: 2 or more likely, below 2 unlikely.
- Three levels: 0 or less low, 1–2 moderate, 3 or more high.
PE: DVT signs 3, PE the most likely diagnosis 3, heart rate above 100 1.5, immobilisation or recent surgery 1.5, previous DVT or PE 1.5, coughing up blood 1, cancer 1.
- Two levels: more than 4 likely, 4 or less unlikely.
- Three levels: below 2 low, 2–6 moderate, more than 6 high.
Worked example
Suspected PE in a patient with a heart rate of 110 and a DVT two years ago: 1.5 + 1.5 = 3. That is unlikely on the two-level scale and moderate on the three-level one, so a D-dimer test is the usual next step.
Suspected DVT with active cancer and a calf 4 cm larger than the other: 1 + 1 = 2, DVT likely.
Tips
- Measure the calves 10 cm below the tibial tuberosity on both legs.
- In pregnancy and in children the Wells scores are less reliable.
- This is an estimate for information, not a diagnosis or a treatment decision.