Wells criteria pe Assessment Tool — Free emergencymedicine Risk Score Calculator

How it Works

Scoring Variables

Clinical signs/symptoms of DVT (leg swelling/pain with palpation) (+3.0 points)

PE is #1 diagnosis or equally likely as alternatives (+3.0 points)

Heart rate > 100 beats per minute (+1.5 points)

Immobilization at least 3 days OR surgery in the previous 4 weeks (+1.5 points)

Previous, objectively diagnosed PE or DVT (+1.5 points)

Hemoptysis (+1.0 points)

Malignancy with treatment within 6 months or palliative (+1.0 points)

Interpretation Thresholds (Two-Tier Model)

Score ≤ 4	PE Unlikely (~12% risk). Order high-sensitivity D-dimer.
Score > 4	PE Likely (~37% risk). Skip D-dimer; proceed directly to CTPA.

Clinical Pearls

Clinical Pearl

The "PE is the most likely diagnosis" criterion carries heavy weight (3 points). It represents the clinician’s gestalt and effectively forces a higher risk tier if the physician strongly suspects PE over alternative diagnoses.

Known Limitations

Heavy reliance on subjective clinician gestalt ("PE #1 diagnosis") makes it less reproducible than strictly objective scores like the Revised Geneva Score.

Cannot be used reliably in patients already on therapeutic anticoagulation.

Not validated for ruling out PE in pregnant women (consider the YEARS algorithm or Geneva pregnancy-adapted score).

Next Steps

Actionable Clinical Management

01

1. If PE Unlikely (≤4): Perform PERC rule first. If PERC negative, stop. If PERC positive, order D-dimer.

02

2. If D-dimer is negative (consider age-adjusted cutoffs): PE is safely excluded.

03

3. If D-dimer is positive, OR if PE Likely (>4): Order a CT Pulmonary Angiogram (CTPA) or V/Q scan if contrast is contraindicated.

04

4. In highly suspicious, hemodynamically unstable patients, initiate empiric heparin before imaging is completed.

The Evidence

Derivation Study

Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer.

Wells PS et al. • Thromb Haemost.. 2000;Vol 83(3): 416-420. Established the simplified 7-variable score in use today, evolving from an earlier, more complex 1998 model.

Origins & History

Development Context

Developed by Dr. Philip Wells, a Canadian hematologist, in 2000. It revolutionized the approach to venous thromboembolism by proving that clinical pre-test probability could be systematically quantified to guide algorithmic diagnostic testing.

Wells Criteria (PE)

When to Use

When to Use

Patient Population

How it Works

Scoring Variables

Interpretation Thresholds (Two-Tier Model)

Clinical Pearls

Clinical Pearl

Known Limitations

Next Steps

Actionable Clinical Management

The Evidence

Derivation Study

Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer.

Origins & History

Development Context

In Recent Clinical News

Wells Criteria (PE)

When to Use

When to Use

Patient Population

How it Works

Scoring Variables

Interpretation Thresholds (Two-Tier Model)

Clinical Pearls

Clinical Pearl

Known Limitations

Next Steps

Actionable Clinical Management

The Evidence

Derivation Study

Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer.

Origins & History

Development Context

In Recent Clinical News