To evaluate the cost-effectiveness of new oral anticoagulants (apixaban, dabigatran and rivaroxaban) compared with each other and with warfarin for patients with atrial fibrillation.
Method:
We developed a decision analytic model, designed as a probabilistic Markov model containing more than 200 probability distributions. The model included eight health states; atrial fibrillation (AF), heart failure, moderate stroke sequela, severe stroke sequela, dead, atrial fibrillation with previous AMI, atrial fibrillation with previous stroke and atrial fibrillation with previous major gastrointestinal bleeding.
Efficacy data was collected from a recently published Health Technology Assessment report. Epidemiological input data was gathered from Scandinavian registries. Data on Quality of Life was based on published EQ-5D data and costs were mainly based on national tariffs.
The analysis was stratified according to risk of stroke as measured by CHA2DS2-VASc and risk of bleeding as measured by HAS-BLED.
Result:
When the new drugs were compared relative to each other for medium risk patients, simulations indicated a 50% probability that apixaban is cost-effective, with 28% and 16% for rivaroxaban and dabigatran, respectively (assuming a WTP of $ 100,000 per QALY). For high risk patients, simulations indicated a 58% probability that dabigatran is cost-effective, with 35% and 4% for apixaban and rivaroxaban, respectively.
When comparing each of the new anticoagulants with the old (warfarin), these analyses indicate a probability up to 54% that warfarin is still cost-effective compared to each of the new oral anticoagulants. In separate analyses, we explored the influence of the drug prices. Conclusions are clearly, highly dependent on the assumed prices of the NOACs.
Conclusion:
Results indicate that there is great uncertainty regarding which treatment is the most cost-effective alternative. Changes in drug prices or different WTP in different jurisdictions may influence the order of prioritizing between oral anticoagulants. Given current evidence, warfarin is likely to remain an alternative to NOACs unless new evidence of efficacy or prices of NOACS are lowered substantially.
See more of: The 35th Annual Meeting of the Society for Medical Decision Making