Wells' Criteria for PE

Calculates the pretest probability of a Pulmonary Embolism (PE). Used to guide the necessity of D-dimer testing versus moving directly to imaging (CTPA).

Clinical signs and symptoms of DVT +3.0

Minimum of leg swelling and pain with palpation of the deep veins

PE is #1 diagnosis OR equally likely +3.0

Alternative diagnosis is less likely than PE

Heart rate > 100 beats per minute +1.5

Immobilization or Surgery +1.5

Immobilization ≥ 3 days OR surgery in the previous 4 weeks

Previous DVT or PE +1.5

Objectively diagnosed

Hemoptysis +1.0

Malignancy +1.0

On treatment, treated in the last 6 months, or palliative

Total Score

NICE Guidelines (NG158)

Score > 4 (PE Likely):
Arrange immediate computed tomography pulmonary angiogram (CTPA). If CTPA cannot be done immediately, offer interim therapeutic anticoagulation. Do not rely on D-dimer.
Score ≤ 4 (PE Unlikely):
Offer a D-dimer test. If positive, arrange CTPA (and give interim anticoagulation if delayed). If D-dimer is negative, PE is reliably excluded.

Note: The "Two-tier" model (>4 vs ≤4) is standard in the UK. A "Three-tier" model exists but is less commonly used.

← Back to all tools