Table 2

Pre-test probability of pulmonary embolism Well’s criteria

Low risk 2 or less; moderate risk 2–6; high risk > 6.
Clinical signs of DVT3.0
Other diagnosis less likely3.0
HR > 1001.5
Stasis or operation in <4/521.5
History of DVT or PE1.5
Active Ca or treatment in <6/121.0
Haemoptysis1.0