[What are the criteria for evaluation and prevention of venous thromboembolism?].

Venous thromboembolism occurs frequently in both medical and surgical units. Although we possess the therapeutic means to prevent this condition, the question is how to assess the benefit induced by a treatment in relation to the haemorrhagic risk? The primary evaluation criteria and the evaluation method must be correctly chosen. While phlebography is the reference method for diagnosing deep venous thrombosis, the limitations associated with this method have led to the promotion of other diagnostic techniques, and clinical criteria or composite criteria are increasingly used. These different approaches--with their respective advantages and limitations--will be developed.