Wells’ Criteria

Wells’ criteria
Clinically suspected DVT 3.0
PE at least as likely or more likely than alternative diagnosis 3.0
Pulse rate >100 1.5
Immobilisation >3 days 1.5
Surgery last 4 weeks 1.5
Previous VTE 1.5
Haemoptysis 1.0
Malignancy 1.0

Wells criteria is a semi-objective way of predicting pre-test probability in a patient with a possible PE.

In the original score patients were divided into three risk groups:

  • Patients scoring <2.0 were considered low risk
  • Patients scoring 2.0 to 6.0 were considered moderate (intermediate) risk
  • Patients scoring >6.0 at high risk of pulmonary embolus

Patients with a score of <2 have a pre-test probability of a PE of less than 15%.

Wells score can also dichotomised to create only 2 risk categories. This revised Wells Score has been adopted by NICE in its 2012 Guideline. In this system:

  • Patients scoring 4 or less are low risk (or PE unlikely)
  • Patients scoring more than 4 are high risk (or PE likely)