Wells Score for Pulmonary Embolism

The combination of a low score by the simple clinical prediction rule and a negative D-Dimer result may safely exclude pulmonary embolism in a large proportion of patients with suspected pulmonary embolism.

Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins).
+3
An alternative diagnosis is less likely than PE
+3
Heart rate greater than 100
+1.5
Immobilization or surgery in the previous four weeks
+1.5
Previous DVT/PE
+1.5
Hemoptysis
+1
Malignancy (on treatment, treated in the last six months or palliative)
+1
Derivation Reference:

Wells, P.S., Anderson D.R., Rodger, M., Ginsberg, J.S., Kearon, C., Gent, M., Turpie, A.G., et al. Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism: Increasing the Models Utility with the SimpliRED D-Dimer. Thrombosis and Haemostasis 83, no. 3 (March 2000): 416–20.

Validation Reference:

Wolf, S.J., McCubbin, T.R., Feldhaus, K.M., Faragher, J.P., Adcock, D.M. Prospective Validation of Wells Criteria in the Evaluation of Patients with Suspected Pulmonary Embolism. Annals of Emergency Medicine 44, no. 5 (November 2004): 503–10. doi:10.1016/j.annemergmed.2004.04.002.