HEALTH LOST BY CHOOSING THE WRONG INTERVENTION – THE CASE OF ORAL ANTICOAGULANTS

Purpose:

When evaluating the three new oral anticoagulants (dabigatran, rivaroxaban and apixaban) for atrial fibrillation in 2012 and 2013, the Norwegian Medicines Agency (NoMA) decided to include all three of the anticoagulants in the national reimbursement system, although only two of the three drugs were deemed cost-effective. The third drug, which was not cost-effective in any scenarios or risk groups, has been the most used in Norway during the first three years after the three were granted reimbursement. We analysed the total health lost due to the inclusion of a not cost-effective alternative in the national health insurance system. 

Method(s):

We used a previously developed Markov model of atrial fibrillation originally constructed to evaluate the cost-effectiveness of new oral anticoagulants compared to established treatment (warfarin). We modelled the lifetime impact of new patients starting on any of the three new oral anticoagulants for different risk groups. Expected remaining quality adjusted life years and costs were calculated for all three drugs. Health lost per patient was calculated both from a patient perspective (direct health lost per patient) and from a health care payer perspective (health lost elsewhere in the society due to higher cost). 

Result(s):

Dabigatran and apixaban were the most cost-effective alternatives in all risk groups. Health lost among patients who started rivaroxaban treatment for atrial fibrillation during the first three years was 0.06 QALYs on average. With approximately 25,000 patients starting this treatment during the three year period, a total of 1600 QALYs can be assumed lost due to the reimbursement of rivaroxaban. In addition, rivaroxaban resulted in increased lifetime costs compared to the other drugs, due to more clinical events. A total of 1400 QALYs can be assumed to be lost elsewhere in the society due to the introduction of rivaroxaban (given a Norwegian threshold of €79,000 per QALY). Probabilistic sensitivity analysis gives a 95% confidence interval which varies from a gain of 1100 QALYs to a loss of 7500 QALYs with rivaroxaban (direct and indirect health loss combined) and a probability of rivaroxaban causing net harm of 92%. 

Conclusion(s):

The decision to include all three new oral anticoagulants in the national reimbursement system in Norway can have led to a net health loss of approximately 3000 QALYs.