Wells Score Calculator for DVT
Calculate the Wells Score to estimate the probability of deep vein thrombosis (DVT) and guide appropriate diagnostic testing.
What is the Wells Score for DVT?
The Wells Score (Wells' Criteria) is a clinical prediction tool that estimates the probability of deep vein thrombosis (DVT). It uses clinical signs, symptoms, and risk factors to stratify patients into low, moderate, or high probability categories. Scores range from -2 to +8. This guides decisions about D-dimer testing and imaging. Validated extensively, it helps avoid unnecessary testing in low-risk patients while identifying high-risk patients needing urgent imaging.
How do I interpret my Wells Score result?
Low probability (<=0 points): DVT prevalence ~5%. D-dimer recommended; if negative, DVT essentially ruled out. Moderate probability (1-2 points): DVT prevalence ~17%. D-dimer if negative can rule out DVT; positive requires ultrasound. High probability (>=3 points): DVT prevalence ~53%. Ultrasound imaging recommended regardless of D-dimer. Higher scores warrant more aggressive investigation and possible empiric anticoagulation pending imaging.
What does "alternative diagnosis more likely" mean?
This criterion (-2 points) is the most subjective component. Alternative diagnoses include: cellulitis, muscle strain/tear, Baker's cyst rupture, superficial thrombophlebitis, chronic venous insufficiency, lymphedema. If clinical presentation better explained by another condition, subtract 2 points. This requires clinical judgment and experience. When uncertain, consider the patient high-risk to avoid missing DVT.
Is the Wells Score accurate?
Wells Score is well-validated with good negative predictive value when combined with D-dimer. Limitations: Subjective elements (especially alternative diagnosis), lower specificity (many false positives), doesn't replace imaging for diagnosis, less accurate in certain populations (pregnancy, cancer, hospitalized patients). Best used as part of comprehensive assessment, not in isolation. Always correlate with clinical judgment and consider patient-specific factors.
What should I do after calculating my Wells Score?
Low risk (<=0): Order D-dimer; if negative, no further testing. Moderate risk (1-2): D-dimer recommended; negative rules out DVT, positive requires ultrasound. High risk (>=3): Proceed directly to compression ultrasound (some protocols still use D-dimer). Any Wells score: Seek immediate medical evaluation if suspecting DVT. This calculator aids clinical decision-making but doesn't replace physician assessment. DVT requires professional diagnosis and treatment.