Table 1.

Clinical characteristics for predicting the pretest probability of deep venous thrombosis. The Wells score model demonstrates well-established criteria for assessment of suspected DVT [22, 23].

Wells score
Clinical characteristics	Score
Active cancer	+1
Paralysis or plaster immobilisation	+1
Bed rest >3 days or major surgery <4 weeks	+1
Localised tenderness along the distribution of the deep venous system	+1
Entire leg swollen	+1
Calf swelling >3 cm when compared with asymptomatic leg	+1
Pitting oedema	+1
Collateral superficial veins (nonvaricose)	+1
Previously documented deep vein thrombosis	+1
Alternative diagnosis at least as likely as deep vein thrombosis	−2
Clinical probability
Unlikely	<2
Likely	≥2