Wells Score for DVT
Assess clinical probability of deep vein thrombosis (DVT) using validated criteria.
Important Medical Disclaimer
This calculator is an educational and clinical decision support tool. Results DO NOT replace professional medical evaluation, laboratory tests, or clinical judgment. Always consult a qualified healthcare professional for diagnosis, treatment, and clinical decisions. Calculations are based on scientifically validated formulas but may not be applicable to all patients.
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What is Wells Score for DVT?
Developed by Wells et al. in 1997 and revised in 2003, it's a clinical decision tool that estimates pre-test probability of deep vein thrombosis (DVT). Combines clinical signs, symptoms, and risk factors to stratify patients into low, moderate, or high probability, guiding need for complementary tests (D-dimer, Doppler ultrasound).
When to use Wells Score?
Use in outpatients with clinical suspicion of lower limb DVT to decide whether to order D-dimer or Doppler ultrasound. Do not use in hospitalized patients (D-dimer frequently elevated by other causes), pregnant women (altered physiology), or suspected pulmonary embolism (use Wells for PE). Combined with D-dimer, can safely exclude DVT in low risk.
Limitations and Considerations
The 'alternative diagnosis' variable is subjective and may vary between evaluators. Score was validated in outpatients, not hospitalized patients. Sensitivity and specificity are moderate; low score doesn't 100% exclude DVT. D-dimer has low specificity (many false positives). Doppler ultrasound is gold standard. Use as screening tool, not definitive diagnosis.
Frequently Asked Questions about Wells DVT
What to do if Wells ≤0 and D-dimer negative?
DVT is highly unlikely (negative predictive value ~99%). Doppler ultrasound not necessary. Consider alternative diagnosis (cellulitis, muscle injury, chronic venous insufficiency). If symptoms persist or worsen, reassess.
What if Wells ≥3 points?
High DVT probability (~53%). Perform Doppler ultrasound immediately, without D-dimer. If ultrasound positive, start anticoagulation. If ultrasound negative but strong clinical suspicion, repeat ultrasound in 1 week or consider venography/CT angiography.
Does Wells apply to hospitalized patients?
Not ideal. Hospitalized patients frequently have elevated D-dimer from other causes (infection, surgery, cancer), reducing specificity. In this context, if DVT suspected, go straight to Doppler ultrasound. Wells was validated in outpatients.
How to treat confirmed DVT?
Immediate anticoagulation (unfractionated heparin, LMWH, or direct oral anticoagulant). Minimum duration 3 months. If provoked risk factor (surgery, immobilization), 3 months. If unprovoked or recurrent, consider prolonged anticoagulation. Assess bleeding risk.