Estimating the Clinical Probability of DVT with Three-Level Wells Score
| Clinical feature | Points |
|---|---|
| History | |
| Active cancer (treatment ongoing, or within previous 6 months, or palliative) | 1 |
| Paralysis, paresis or recent plaster immobilization of the leg | 1 |
| Recently bedridden for more than 3 days, or major surgery within 4 weeks | 1 |
| Examination | |
| Localized tenderness along the distribution of the deep venous system | 1 |
| Entire leg swollen | 1 |
| Calf swelling by >3 cm when compared with asymptomatic leg (measured 10 cm below tibial tuberosity) | 1 |
| Pitting oedema (greater in the symptomatic leg) | 1 |
| Collateral superficial veins (non-varicose) | 1 |
| Alternative diagnosis? | |
| An alternative diagnosis (Table 56.3) is as likely or more likely than DVT | –2 |
| Clinical probability of DVT | |
| Score 3 or more: high probability | |
| Score 1 or 2: intermediate probability | |
| Score 0 or less: low probability | |
Source: Wells PS et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet 1997; 350: 1795–1798. Reproduced with permission of Elsevier.