Wells Score Calculator (DVT) Formula
Understand the math behind the wells score calculator (dvt). Each variable explained with a worked example.
Formulas Used
Wells Score
wells_total = active_cancer + paralysis + bedridden + tenderness + leg_swelling + calf_difference + pitting_edema + collateral_veins + alternative_diagnosisMaximum Possible Score
risk_category = 8Variables
| Variable | Description | Default |
|---|---|---|
active_cancer | Active Cancer? | 0 |
paralysis | Paralysis/Immobilization of Leg? | 0 |
bedridden | Bedridden >3 days or Major Surgery <12 wks? | 0 |
tenderness | Tenderness Along Deep Vein? | 0 |
leg_swelling | Entire Leg Swollen? | 0 |
calf_difference | Calf >3 cm Larger Than Other? | 0 |
pitting_edema | Pitting Edema in Symptomatic Leg? | 0 |
collateral_veins | Collateral Superficial Veins? | 0 |
alternative_diagnosis | Alternative Diagnosis as Likely? | 0 |
How It Works
Wells Score for DVT
The Wells score estimates the pre-test probability of deep vein thrombosis.
Scoring Criteria
Each criterion scores +1 point, except "alternative diagnosis as likely" which scores -2.
Risk Categories
| Score | Probability | DVT Prevalence | |---|---|---| | 0 or less | Low | ~5% | | 1-2 | Moderate | ~17% | | 3+ | High | ~53% |
Patients with low probability and negative D-dimer can safely avoid imaging.
Worked Example
A patient with active cancer, bedridden >3 days, and calf swelling.
active_cancer = 1paralysis = 0bedridden = 1tenderness = 0leg_swelling = 0calf_difference = 1pitting_edema = 0collateral_veins = 0alternative_diagnosis = 0
- 01Active cancer = +1
- 02Bedridden >3 days = +1
- 03Calf >3 cm larger = +1
- 04Total = 3 (High probability)
Ready to run the numbers?
Open Wells Score Calculator (DVT)