Emerging evidence indicates combination therapy with anticoagulants and antiplatelet agents for atrial fibrillation (AF) will be increasingly required. Numerous studies compare the efficacy and cost-effectiveness of anticoagulation alone in AF, i. e., non-vitamin K oral anticoagulants (NOACs) vs. warfarin. However, the addition of antiplatelet agents with their potential for decreasing thromboembolic stroke counter-balanced by an increased bleeding risk has received less attention. Thus, we evaluated the cost utility of this combination therapy.
Method and results
We obtained event estimates from our recent meta-analysis of four randomized clinical trials designed to compare NOACs with warfarin in patients with AF. We examined patient subgroups within each trial that received antiplatelet therapy in addition to anticoagulation. Utilities were derived from the literature and cost estimates from the German health-care system. A decision tree was constructed and populated with these parameters. We used a 1-year time horizon because combination therapy is not recommended beyond this time. We calculated the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY). The derived ICER was 13,168.50 € per QALY. NOAC prices exerted considerable influence on the calculation. Nevertheless, there is potential for ICER shifts in favor of warfarin, eg, if warfarin-mediated anticoagulation control is improved and thereby adverse events decrease. Conversely, if NOAC adherence decreases, adverse events could increase.
The derived ICER was 13,168.50 € per QALY, consistent with NOACs being cost-effective vs. warfarin when anticoagulation is used with antiplatelet agents.
Nevertheless, country, practice, and patient-related factors influence the ICER. Our cost utility calculation should be used at a starting point for decision-making.