Wells Score for Pulmonary Embolism (PE)

Calculate Wells Score for pulmonary embolism (PE). Estimate pretest probability and guide the decision between D-dimer testing and CT pulmonary angiography (CTPA).

Based on: Wells 2000

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Wells Score

0/ 12.5

Clinical factors

Clinical signs of DVT+3

Leg swelling, tenderness, or other findings suggesting deep vein thrombosis

Clinical judgment required

PE is the most likely diagnosis+3

Clinical judgment that PE is more likely than alternative diagnoses (pneumonia, heart failure, COPD exacerbation, etc.)

Check if PE is more likely than alternative diagnoses (e.g., pneumonia, heart failure, COPD exacerbation) based on your overall clinical assessment

Heart rate > 100 bpm+1.5

Resting heart rate greater than 100 beats per minute

Immobilization or surgery in past 4 weeks+1.5

Bed rest ≥ 3 days or surgery within the past 4 weeks

Previous DVT or PE+1.5

Objectively confirmed prior deep vein thrombosis or pulmonary embolism

Hemoptysis+1

Coughing up blood or blood-streaked sputum

Malignancy+1

Active cancer under treatment, treated within the past 6 months, or receiving palliative care

Clinical reasoning

A 62-year-old man presents with sudden dyspnea 4 days after total knee replacement. HR 106/min. No DVT signs.

What is the next best step?

A 45-year-old woman presents with pleuritic chest pain. HR 82/min, no recent surgery, no DVT signs, no hemoptysis, no malignancy, no prior DVT/PE. Pleuritis seems more likely than PE.

What is the next best step?

Overview

Wells Score for pretest probability assessment of pulmonary embolism (PE). Three-tier risk classification guides the D-dimer versus CT pulmonary angiography (CTPA) decision.

Evidence Summary

The Wells Score was developed by Wells et al. (2000) as a validated clinical prediction rule for PE pretest probability. The criterion 'PE more likely than alternative diagnosis' is the most subjective component, requiring clinical gestalt — the clinician must weigh the entire clinical picture against competing diagnoses.

The three-tier classification (low, moderate, high) guides the selection between D-dimer testing and imaging. At low probability, a highly sensitive D-dimer negative result may exclude PE. At high probability, D-dimer adds no diagnostic value, and CTPA should be performed without delay.

Wells Score risk categories and PE probability
Score	Risk category	PE probability (Wells 2000)	Recommended approach
< 2	Low	≈10%	D-dimer testing
2–6	Moderate	≈28%	D-dimer or CTPA
> 6	High	≈66%	Direct CTPA

Wells Score for Pulmonary Embolism (PE)

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Overview

Evidence Summary

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