OBJECTIVE: To determine the cost-effectiveness of apixaban versus warfarin in 
patients with atrial fibrillation (AF) with a moderate to severe risk of stroke, 
from an Australian government-perspective.
METHODS: A decision-analytic Markov model was constructed to assess the 
cost-effectiveness of apixaban versus warfarin, based on data from the Apixaban 
for Reduction in Stroke and Other Thromboembolic Events in AF (ARISTOTLE) trial. 
The model comprised five health states: 'Alive, no major bleeding or stroke', 
'Alive, no major bleeding, post stroke/systemic embolism', 'Alive, post major 
bleeding, no stroke', 'Alive, post-major bleeding and stroke' and 'Dead'. 
Disease cost data was derived from the North-East Melbourne Stroke Incidence 
Study and the Australian Refined Diagnose Related Groups. Costs of medications 
were based on data from the Pharmaceutical Benefit Scheme. Utility data was 
derived from published sources, and an annual discount rate of 5% was applied to 
costs and benefits. The main outcome of interest was incremental 
cost-effectiveness ratios per life year gained (LYG) and quality adjusted life 
years (QALYs) gained.
RESULTS: Over 20 years, in the sample of 1000 subjects the model predicted that 
compared to warfarin, apixaban led to a (discounted) of 0.33 LYG and 0.31 QALYs 
gained, at a net cost of $4,308 per-person. These equated to ICERs of $AUD12, 
914 per LYG and $AUD13, 679 per QALY gained. Probabilistic sensitivity analysis 
demonstrated that apixaban was cost-effective at 99.0% probability using 
willingness to pay thresholds of $AUD45 000 per LYG and QALY.
CONCLUSION: Compared to warfarin, apixaban is likely to represent a 
cost-effective means of preventing stroke-related morbidity and mortality in 
patients with AF.