Table 1.

Two level Wells score for pulmonary embolism

Symptom	Score
Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins)	3
An alternative diagnosis is less likely than PE	3
Heart rate >100 beats/minute	1.5
Immobilisation or surgery in the previous 4 weeks	1.5
Previous DVT/PE	1.5
Haemoptysis	1
Malignancy (on treatment, treated in the last 6 months, or palliative)	1
Clinical probability	Total score
PE unlikely	≤4
PE likely	>4

DVT = deep vein thrombosis; PE = pulmonary embolism.