Table 1 How to assess clinical probability according to the scoring system of Wells et al. [11]
Clinical history and signsScore
Suspected DVT3.0
An alternative diagnosis is less likely than PE3.0
Heart rate >100 beats per min1.5
Immobilisation or surgery in the previous 4 weeks1.5
Previous DVT or PE1.5
Haemoptysis1.0
Malignancy (on treatment, treated in the past 6 months or palliative)1.0
Risk of having PEScore rangeMean probability of PE %
Low probability<23.6
Intermediate probability2–620.5
High probability>666.7

  • DVT: deep venous thrombosis; PE: pulmonary embolism.