Table 1.

 Items of Wells pulmonary embolism rule

Variables	Points
Clinical signs and symptoms of deep vein thrombosis (minimum of leg swelling and pain with palpation of deep veins)	3.0
Pulmonary embolism more likely than alternative diagnosis	3.0
Heart rate >100 beats/min	1.5
Immobilisation (>3 days) or surgery in previous four weeks	1.5
Previous pulmonary embolism or deep vein thrombosis	1.5
Haemoptysis	1.0
Malignancy (receiving treatment, treated in past six months, or palliative)	1.0