Risk factors for venous thromboembolism - layout option 2

 

Risk factor

Comments

Age
  • Incidence of first VTE rises exponentially with age
  • Less than 40 years - annual incidence of 1/10,000
  • 60-69 years - annual incidence of 1/1000
  • Greater than 80 years - annual incidence of 1/100

Obesity

  • 2-3 fold VTE risk if obese (body mass index greater than or equal to 30kg/m2)

Varicose veins

  • 1.5-2.5 - fold risk after major general/orthopaedic surgery
  • Low risk after varicose vein surgery

Previous VTE

  • Recurrence rate 5% per year after an unprovoked VTE
  • Risk of recurrence VTE increased 1.6 fold in males vs females
  • 5-fold increased risk of postoperative VTE in patients with prior VTE

Family history of VTE

  • A history of at least one first degree relative having had VTE less than 50 years or more than one first degree relative with VTE history regardless of age is an indicator of increased risk of first VTE (but not of recurrent VTE)

Thrombophilia

  • Patients with known thrombophilia; no need to routinely perform a thrombophilia screen as part of risk assessment.

Cancer

  • Active cancer: compared with general population overall 5-7 -fold risk of first VTE and increased risk of recurrent VTE. Risk varies with type of cancer. Further increased risk associated with surgery, chemotherapy, use of erythropoeisis stimulating agents and central venous catheters.
Other thrombotic states
  • Cardiac failure, recent myocardial infarction
  • Stroke
  • Metabolic syndrome: 2-fold increased risk of VTE
  • Severe acute infection e.g. pneumonia
  • Chronic HIV infection
  • Inflammatory bowel disease
  • Nephrotic syndrome
  • Myeloproliferative disease
  • Paraproteinaemia
  • Bechet’s disease
  • Warm autoimmune haemolytic anaemia

Hormone therapy

  • Combined oral contraceptive pill, oral hormone replacement therapy, raloxifene, tamoxifen, high dose progestogens.

Pregnancy, puerperium

  • See Royal College of Obstetrics and Gynaecologists (RCOG) guidelines Links given page 5

Immobility

  • For example bed rest more than 3 days, plaster cast, paralysis: 10-fold increased VTE risk; increases with duration

Hospitalisation

  • Acute trauma, acute illness, surgery: 10-fold increased VTE risk

Anaesthesia

  • 2-3 fold reduced risk of post operative VTE with spinal/epidural

Central Venous Catheters (CVC)

  • Compared with subclavian access, femoral route 11.5-fold increased risk of VTE