Highest Risk Category in the Caprini Risk Assessment Model
The highest risk category in the Caprini risk assessment model is a score of ≥9, which is associated with the highest rates of postoperative venous thromboembolism (VTE). 1
Risk Stratification Categories
The Caprini RAM categorizes patients into four distinct risk groups based on cumulative point scores 1:
- Score 3-4: Moderate risk
- Score 5-6: High risk
- Score 7-8: Higher risk
- Score ≥9: Highest risk category with the greatest VTE rates 1
VTE Rates by Risk Category
The correlation between Caprini scores and DVT incidence demonstrates a clear dose-response relationship 1:
- Patients with scores 3-4 have approximately 3% VTE risk 2
- Patients with scores 5-8 have approximately 2% DVT incidence 3
- Patients with scores 9-11 have 26% DVT incidence 3
- Patients with scores 12-15 have 65% DVT incidence 3
A validation study in high-risk surgical patients found that compared to patients with scores 5-8, the risk for DVT increased 18.7-fold for scores 9-11 and 98.4-fold for scores 12-15 3.
Clinical Significance of Score ≥9
Patients with Caprini scores ≥9 represent the highest risk group and require the most aggressive thromboprophylaxis strategies 1. This threshold has been validated across multiple populations and surgical settings 3, 4.
Important Threshold Considerations:
- A Caprini score ≥11 identifies an extremely high-risk subgroup with 59% DVT incidence, compared to only 3% in patients with scores <11 3
- The area under the ROC curve was 0.87 for predicting DVT, with a score of 11 providing optimal sensitivity and specificity 3
- In Chinese hospitalized patients, those in the highest risk group (score ≥9) had 16.12-fold greater risk compared to low-risk patients 4
Common Pitfalls
Do not assume all patients with "high risk" scores require identical management 1. The evidence demonstrates substantial variation in VTE rates even within the highest risk category (scores ≥9), with particularly elevated rates at scores ≥11-12 3. Standard prophylaxis may be insufficient for patients with scores ≥11, who may require more intensive prophylactic regimens 3.
Avoid using inconsistent risk category definitions, as systematic reviews have identified significant heterogeneity in how centers operationalize Caprini scores into risk categories, with cutoff scores ranging from ≥5 to ≥10 for "high risk" 5. The most validated approach uses score ≥9 as the highest risk threshold 1.