A score of ≤0
Low Pretest Probability
| Clinical Characteristic | Points |
| Active cancer (chemotherapy within 6 months or current palliative care) | 1 |
| Paralysis, paresis, or recent plaster cast immobilization of the lower extremity | 1 |
| Recently bedridden for 3+ days, or major surgery within prior 12 weeks requiring general or regional anesthesia | 1 |
| Localized tenderness along deep vein distribution | 1 |
| Entire leg swollen | 1 |
| Calf swelling ≥3cm more than asymptomatic leg (measure 10cm below tibial tuberosity) | 1 |
| Pitting edema confined to symptomatic leg | 1 |
| Collateral superficial veins visible (non-varicose) | 1 |
| Previously documented DVT | 1 |
| Alternative diagnosis at least as likely as DVT | -2 |