An Evidence-Based Decision-Analytical Approach to Determine Optimal Duration of Anticoagulation for Venous Thromboembolism
Based on Djulbegovic & Greenberg (Blood Advances, 2025)
Fill in the patient parameters and click "Calculate Recommendation" to see the decision analysis results.
Use this tool to systematically elicit patient values using the regret-based approach. The Relative Value (RV) represents how the patient weighs avoiding VTE recurrence versus avoiding major bleeding.
"How many more times would you regret receiving unnecessary (harmful) anticoagulant treatment that may not have benefited you at all, compared to not receiving treatment that could have prevented a serious event?"
Select a clinical scenario to see how the decision-analytical framework applies to real patient cases.
Otherwise healthy man with bilateral PE during daily run. Completed 6 months of apixaban with negative thrombophilia evaluation. Strongly prefers to avoid recurrent PE.
Key features: Unprovoked, low bleeding risk, RV ≈ 0.5-1
PE developed 3 weeks after >8-hour flight. No personal/family VTE history. Flies to Asia twice yearly. Completed 3 months of apixaban. Undecided about values (RV = 1).
Key features: Travel-related, occasional flyer, low bleeding risk
4-year history of primary biliary cirrhosis with portal vein thrombosis. Platelets 50,000/μL. Recent variceal bleeding requiring banding. Uncertain about values (RV = 1).
Key features: High bleeding risk, persistent VTE risk, cirrhosis
Explore how VTE recurrence risk and treatment thresholds change over time with different parameters.
Select options above to see interpretation.
This tool implements a threshold decision model for VTE anticoagulation duration. Treatment is justified when the risk of VTE recurrence exceeds the treatment threshold.
Use the "Patient Values (RV)" tab to systematically determine how your patient weighs VTE recurrence against bleeding risk. This is crucial for personalized recommendations.
In the "Decision Calculator," enter the patient's VTE type, bleeding risk category, and other relevant parameters.
Review the calculated threshold, VTE risk projections, and recommended duration. Use the visualization to understand how risks evolve over time.
The model is a starting point. Integrate findings with clinical intuition, patient-specific factors, and shared decision-making.
The threshold is the VTE recurrence risk at which we are indifferent between continuing or stopping anticoagulation. It is calculated as:
Where RV is the relative value (patient preferences), and RRR is the relative risk reduction from anticoagulation.
RV is calculated as: Regret of Commission / Regret of Omission
For unprovoked VTE, cumulative recurrence risk (Khan et al.):
For travel-related VTE, risk decays exponentially based on travel frequency:
| Category | Baseline Risk | On Anticoagulation |
|---|---|---|
| Low Risk | 0.5%/year | ~1.1%/year (RR 2.17) |
| High Risk | 1.5%/year | ~3.3%/year (RR 2.17) |
| Very High (e.g., cirrhosis) | 4%/year | ~14%/year (RR 3.5) |
This tool implements the decision-analytical framework described in:
"How to Determine the Optimal Duration of Anticoagulation for VTE: An Evidence-Based Decision-Analytical Approach"
Benjamin Djulbegovic, MD, PhD and Charles Greenberg, MD
Medical University of South Carolina
Blood Advances, 2025
Uses meta-analytic data from high-quality studies (Khan et al., ASH Guidelines)
Incorporates systematic elicitation of patient values and preferences
Makes the decision-making process explicit and reproducible
Adapts recommendations to patient-specific risk profiles
This tool is for educational and clinical decision support purposes only.
It does not replace clinical judgment, shared decision-making with patients, or consideration of individual patient factors not captured by the model. Always reassess recommendations periodically and when patient circumstances change.
| Parameter | Source | Evidence Quality |
|---|---|---|
| VTE Recurrence Risk | Khan et al. BMJ 2019; Kyrle et al. JTH 2016 | High |
| RRR for Anticoagulation | ASH 2020 Guidelines | High |
| Bleeding Risk (RR) | ASH 2020 Guidelines | High |
| Travel-Related VTE Decay | MacCallum et al. BJH 2011 | Moderate |
| Portal Vein Thrombosis | Giri et al. JGH 2023 | Moderate |
For questions about the underlying methodology, contact:
Benjamin Djulbegovic, MD, PhD
Professor of Medicine
Medical University of South Carolina
djulbegov@musc.edu