6th July 2026

Epidemiology

VTE is a very common occurrence worldwide. Within the UK, there is an estimated incidence of 1-2 per 1000 individuals. It can be both the presenting complaint of a patient (patient related) as well as a complication or incidental occurrence whilst in hospital (admission related). As such, it is essential to be able to assess patient risk for VTE and follow the appropriate guidelines for VTE prophylaxis. This is done by weighing the risk of thrombosis against the risk of bleeding. Risk factors for thrombosis can be divided into patient related or admission related. 

Patient related risk factors

• Active cancer or treatment for cancer
• Age over 60 years
• Thrombophilia
• Obesity (BMI > 30)
• One or more significant medical comorbidities 
• Personal or family history (first degree relative) of VTE 
• Medications, including Hormone replacement therapy and contraception containing oestrogen
• Dehydration
• Pregnancy
• Less than 6 weeks postpartum  

Admission related risk factors

• Hip or knee replacement
• Hip fracture
• Significantly reduced mobility for 3 days or more
• Total anaesthetic + surgical time > 90 minutes
• Surgery involving the pelvic region or lower limbs with a total anaesthetic + surgical time > 60 minutes 
• Acute surgical admission with inflammatory or intra-abdominal pathology
• Critical care admission
• Surgery with significant reduction in mobility