| Clinical feature | Score |
| Active cancer (treatment ongoing or within the previous six months or palliative) | 1 |
| Paralysis, paresis, or recent plaster immobilization of the lower extremities | 1 |
| Recently bedridden for more than three days or major surgery, within four weeks | 1 |
| Localized tenderness along the distribution of the deep venous system | 1 |
| Entire leg swollen | 1 |
| Calf swelling by more than 3 cm when compared to the asymptomatic leg (measured below tibial tuberosity) | 1 |
| Pitting edema (greater in the symptomatic leg) | 1 |
| Collateral superficial veins (nonvaricose) | 1 |
| Alternative diagnosis as likely or more likely than that of deep venous thrombosis | -2 |
| Score | |
| High probability | 3 or greater |
| Moderate probability | 1 or 2 |
| Low probability | 0 or less |
| Modification: | |
| This clinical model has been modified to take one other clinical feature into account: a previously documented deep vein thrombosis (DVT) is given the score of 1. Using this modified scoring system, DVT is either likely or unlikely, as follows: | |
| DVT likely | 2 or greater |
| DVT unlikely | 1 or less |
