Caprini Score Calculation and Application
The Caprini risk assessment model assigns points (1,2,3, or 5 points) to individual VTE risk factors, with the total score determining risk stratification: 0 = very low risk, 1-2 = low risk, 3-4 = moderate risk, and ≥5 = high risk, guiding prophylaxis decisions according to established thresholds. 1
How to Calculate the Caprini Score
The Caprini model uses a weighted point system where you add points for each risk factor present 1:
1-Point Risk Factors:
- Age 41-60 years
- Minor surgery
- Swollen legs
- Varicose veins
- Pregnancy or postpartum
- History of unexplained/recurrent spontaneous abortion
- Oral contraceptives or hormone replacement therapy
- Sepsis (<1 month)
- Serious lung disease including pneumonia (<1 month)
- Abnormal pulmonary function
- Acute myocardial infarction
- Congestive heart failure (<1 month)
- History of inflammatory bowel disease
- Medical patient at bed rest
2-Point Risk Factors:
- Age 61-74 years
- Arthroscopic surgery
- History of VTE
- Laparoscopic surgery (>45 minutes)
- Malignancy
- Confined to bed (>72 hours)
- Immobilizing plaster cast
- Central venous access
3-Point Risk Factors:
- Age ≥75 years
- Major open surgery (>45 minutes)
- Family history of VTE
- Factor V Leiden
- Prothrombin 20210A
- Lupus anticoagulant
- Anticardiolipin antibodies
- Elevated serum homocysteine
- Heparin-induced thrombocytopenia
- Other congenital or acquired thrombophilia
5-Point Risk Factors:
- Stroke (<1 month)
- Elective arthroplasty
- Hip, pelvis, or leg fracture
- Acute spinal cord injury (<1 month)
Risk Stratification and Prophylaxis Algorithm
Very Low Risk (Score 0):
No pharmacologic or mechanical prophylaxis required beyond early ambulation. 1
Low Risk (Score 1-2):
Use mechanical prophylaxis with intermittent pneumatic compression (IPC) rather than no prophylaxis. 1 Pharmacologic prophylaxis is not indicated at this level.
Moderate Risk (Score 3-4):
For patients without high bleeding risk: Use LMWH or low-dose unfractionated heparin (LDUH). 1
For patients with high bleeding risk: Use mechanical prophylaxis with IPC until bleeding risk diminishes, then initiate pharmacologic prophylaxis. 1
High Risk (Score ≥5):
For patients without high bleeding risk: Use LMWH or LDUH, and add mechanical prophylaxis (elastic stockings or IPC) to pharmacologic prophylaxis. 1
For cancer patients undergoing abdominal or pelvic surgery: Extend pharmacologic prophylaxis with LMWH for 4 weeks postoperatively rather than limiting to hospital stay only. 1
For patients with high bleeding risk: Use mechanical prophylaxis with IPC until bleeding risk decreases, then add pharmacologic prophylaxis. 1
Critical Thresholds Across Specialties
Recent validation studies demonstrate that VTE risk increases dramatically at specific score thresholds: ≥7, ≥9, and ≥11-12, with extremely high VTE incidence (13-47%) observed at scores ≥9 to ≥11-12 in surgical specialties including cancer, trauma, vascular, general, head and neck, and thoracic surgery. 2 For joint arthroplasty specifically, scores ≥9 represent a particularly high-risk threshold for postoperative VTE. 3
Important Caveats
The Caprini score performs poorly in hospitalized medical patients, where VTE incidence remains extremely low (1.05%) despite elevated scores, and no clear cut-point demonstrating benefit from prophylaxis was identified. 4 The model was originally developed and validated primarily for surgical populations.
In Asian surgical populations, the overall VTE incidence is substantially lower (0.5%), and applying standard Caprini thresholds would result in approximately 85% of patients receiving prophylaxis, representing potential overtreatment. 5 Consider population-specific risk when applying this model.
For joint arthroplasty patients in safety-net hospital populations with increased medical complexity, institution-specific risk assessment tools may outperform the Caprini model. 6
Do not use inferior vena cava filters for primary VTE prevention regardless of Caprini score. 1