Economic Evaluation of Warfarin, Dabigatran, Rivaroxaban, and Apixaban for Stroke Prevention in Atrial Fibrillation

BACKGROUND Atrial fibrillation is a major risk factor for stroke, which causes thousands of deaths and sequelae. It is recommended that atrial fibrillation patients at medium or high risk of stroke use an oral anticoagulant to reduce the risk of stroke. In the past few years, three new oral anticoagulants (NOACs), dabigatran, rivaroxaban, and apixaban, have been introduced in competition to the older oral anticoagulant warfarin. OBJECTIVE The objective of this study was to evaluate the relative cost effectiveness of warfarin, dabigatran, rivaroxaban, and apixaban in a Norwegian setting. METHODS We created a probabilistic decision-analytic Markov model to simulate the life of patients with atrial fibrillation. We performed several scenario analyses, including changing the switching age for dabigatran from 80 to 75 years old. RESULTS Assuming the European Society of Cardiology guidance, sequential dabigatran (2 × 150 mg daily until 80 years old, 2 × 110 mg thereafter) seems to be the most cost-effective alternative for high-risk AF patients. For medium-risk patients, apixaban (2 × 5 mg daily) seems to be somewhat more effective than dabigatran, but dabigatran is still marginally the most cost-effective alternative. In scenario analyses reducing dabigatran from 2 × 150 mg to 2 × 110 mg at the age of 75 years (instead of at age 80), apixaban (2 × 5 mg daily) becomes the most cost-effective alternative for both risk groups. CONCLUSION We have found apixaban or sequential dabigatran to be the alternatives most likely to be considered cost effective, depending on the switching age for dabigatran. These conclusions are highly sensitive to assumptions made in the analysis.