Wells' Score Calculator

Estimate the pre-test probability of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) using the validated Wells scoring system. This tool helps guide diagnostic testing decisions.

Wells Score Calculator

For Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) Risk Assessment

DVT Risk Factors

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DVT Wells Score Result

Score: 0

Probability:

Recommendation:

What is the Wells' Score?

The Wells' Score is a clinical prediction rule used to estimate the pre-test probability of venous thromboembolism, specifically Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE). Developed by Dr. Philip Wells, these scoring systems help clinicians determine the appropriate diagnostic approach for patients with suspected thromboembolism.

There are separate Wells scores for DVT and PE, each incorporating different clinical factors and risk elements. The scores help stratify patients into low, moderate, or high probability categories, which then guide decisions about D-dimer testing, imaging studies, and treatment initiation.

These tools are particularly valuable in emergency departments and outpatient settings where rapid, evidence-based decision-making is crucial for patient safety and resource utilization.

Using the Score for DVT vs. PE

DVT Wells Score

Low Risk (≤0 points): 5% probability

D-dimer; if negative, DVT ruled out

Moderate Risk (1-2 points): 17% probability

D-dimer; if positive, ultrasound required

High Risk (≥3 points): 53% probability

Ultrasound required

PE Wells Score

Low Risk (<2 points): 1.3% probability

D-dimer; if negative, PE ruled out

Moderate Risk (2-6 points): 16.2% probability

D-dimer; if positive, CT-PA or V/Q scan

High Risk (>6 points): 40.6% probability

CT-PA or V/Q scan recommended

Interpretation and Next Steps

D-dimer Testing

D-dimer is most useful in low and moderate probability patients. A negative D-dimer in low-risk patients effectively rules out VTE. In moderate-risk patients, a negative D-dimer significantly reduces the probability, while a positive result necessitates imaging.

Imaging Studies

High-risk patients typically require immediate imaging regardless of D-dimer results. For DVT, compression ultrasound is the first-line imaging. For PE, CT pulmonary angiogram (CT-PA) or ventilation-perfusion (V/Q) scan are appropriate options.

Clinical Integration

The Wells score should be used in conjunction with clinical judgment and institutional protocols. Consider patient factors such as pregnancy, contraindications to imaging, and bleeding risk when making treatment decisions.

Example Cases

DVT Case Study

A 45-year-old woman presents with left leg swelling and pain 2 weeks after a long flight. She has no history of cancer or recent surgery. On examination, her entire left leg is swollen with localized tenderness along the deep venous system.

✓ Entire leg swollen: +1 point

✓ Localized tenderness: +1 point

✗ Alternative diagnosis likely: 0 points

DVT Wells Score: 2 points

Moderate risk (17%) - Obtain D-dimer; if positive, perform ultrasound

PE Case Study

A 62-year-old man with lung cancer presents with sudden onset shortness of breath and chest pain. His heart rate is 110 bpm. He has clinical signs of DVT in his right leg, and PE is considered the most likely diagnosis.

✓ Clinical signs of DVT: +3 points

✓ PE most likely diagnosis: +3 points

✓ Heart rate >100: +1.5 points

✓ Active malignancy: +1 point

PE Wells Score: 8.5 points

High risk (40.6%) - Proceed directly to CT-PA or V/Q scan

Frequently Asked Questions about the Wells' Score

Dr. Eleanor Vance, MD, FACC

Cardiology, Electrophysiology

Dr. Eleanor Vance is a board-certified cardiologist with over 15 years of experience specializing in cardiac electrophysiology and the management of atrial fibrillation. After graduating summa cum laude from Johns Hopkins School of Medicine, she completed her residency at Massachusetts General Hospital and a fellowship in cardiology at the Cleveland Clinic.

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