Thrombosis Knowledge Centre
Risk Factors
Risk Stratification for VTE
To optimise treatment, patients with VTE may be stratified into risk categories to adapt thromboprophylaxis according to the risk. The risk increases in proportion to the number of risk factors.
Anderson and Spencer. Circulation 2003;107:I-9-I16
Table 1. Stratification for VTE
| Level of risk | Patient characteristics |
|---|---|
| Low (odds ratio <2) |
- Bed rest >3 days - Immobility due to sitting (e.g. air travel) - Higher age - Laparoscopic surgery - Obesity - Pregnancy (antepartum) - Varicose veins - Laparoscopic surgery |
| Moderate (odds ratio 2-9) |
- Arthroscopic knee surgery - Central venous lines - Chemotherapy - Congestive heart or respiratory failure - Hormone replacement therapy - Malignancy - Oral contraceptive therapy - Paralytic stroke - Pregnancy (postpartum) - Previous VTE - Thrombophilia |
| High (odds ratio >10) |
- Fracture (hip or leg) - Hip or knee replacement - Major general surgery - Major trauma - Spinal cord injury |
Table reference: Anderson and Spencer. Circulation 2003;107:I-9-I16
Table 2. Levels of Thromboembolism Risk in Hospital Patients
Stratification for VTE
| Level of risk | Patient characteristics | Approximate DVT Risk Without Thromboprophylaxis % |
|---|---|---|
| Low |
Minor surgery in mobile patients Medical patients who are fully mobile |
< 10 |
| Moderate | Most general, open gynaecologic or urologic surgery patients Medical patients, bed rest or sick |
10–40 |
| High | Hip or knee arthroplasty, Hip Fracture Surgery Major trauma, Spinal Cord Injury |
40–80 |
Tabel reference: Geerts et al. Chest 2008; 133; 381-453
What are the medical situations carrying an increased risk for VTE?
Medical contexts have been less explored than surgical contexts in terms of VTE risk, being heterogeneous and more difficult to study.
Table 3. Medical situations involving a risk of VTE
| Acute medical situation | Chronic medical condition |
|---|---|
| Acute congestive heart failure | Advanced age |
| Acute inflammatory bowel disease | Chronic heart failure |
| Acute infl ammatory rheumatic disease | Chronic respiratory failure |
| Acute respiratory failure | Hormonal therapy |
| Acute, severe infectious disease | Obesity |
| Central venous catheter | Personal or family history of VTE |
| Ischaemic stroke | Varicose veins |
| Myeloproliferative syndrome | |
| Neurological disease with paraplegia | |
| Active cancer |
Table reference: Bergmann and Kehr. Int J Clin Pract 2005; 59:555-61
Risk assessment model for hospitalised medically ill patients.Patients are stratified by acute medical illness and the presence
of predisposing risk factors.
Cohen AT. Thromb Haemost 2005;95:750-9