Table I.

Wells model for clinical diagnosis of PE

Signs and symptoms	Points
Clinical signs and symptoms of DVT	3
Pulmonary embolism as likely or more likely than an alternative diagnosis	3
Heart rate > 100 beats/min	1.5
Immobilization (bed rest for at least 3 consecutive days) or surgery in the previous 4 weeks	1.5
Previous objectively diagnosed DVT or PE	1.5
Haemoptysis	1.0
Malignancy (treatment that is ongoing, within the past 6 months, or palliative)	1.0