Table 1

 Incidence of venous thromboembolism in various risk categories

Risk categoryLow riskMedium riskHigh risk
General surgeryAge <40 yearsAge >40 yearsAge >60 years
Surgery <30 minSurgery >30 minSurgery >60 min
No risk factorsNo other risk factorsPlus additional risk factors
Orthopaedic surgery, traumatologyMinor traumaLeg plaster castHip or knee surgery, hip fracture, polytrauma
Medical conditionsPregnancyHeart failure, stroke, malignancyLong immobility
Incidence, %
    Distal DVT210–4040–80
    Proximal DVT0.46–810–15
    Symptomatic pulmonary embolism0.21–25–10
    Fatal pulmonary embolism0.0020.1–0.81–5