OBJECTIVES: Atrial fibrillation (AF) is a common arrhythmia associated with debilitating consequences such as stroke, heart failure and venous thromboembolism. In HK, 20-25% of stroke cases are related to AF leading to a significant burden. Warfarin has been the frontline oral anticoagulant for AF but with high bleeding risk and hence monitoring and dose adjustment are required. The non-vitamin-K antagonist oral anticoagulants (NOACs) are alternatives to warfarin for preventing stroke and systemic embolism in non-valvular AF (NVAF) patients. This study aims to evaluate the cost-effectiveness of edoxaban in HK as an alternative to rivaroxaban or warfarin.

METHODS: A Markov model with monthly cycle length was populated with epidemiological and economic parameters to project cost-effectiveness of edoxaban over life-time horizon. Probabilities of clinical events for edoxaban and rivaroxaban compared to warfarin were derived from a network meta-analysis. Data on resource utilization and treatment cost of clinical events were derived from primary data from hospitals in HK or published literature. Health state utilities and treatment discontinuation rates were extrapolated from literatures. All costs were 2017 figures and cost and effectiveness were both discounted at 3% per annum. Sensitivity analyses were performed to test model robustness.

RESULTS: Total per-patient healthcare cost over remaining lifetime horizon for high-dose edoxaban was lower than rivaroxaban by US$2,437 with mean QALYs gained of 0.054 per patient, suggesting endoxaban being dominant over rivaroxaban. Similar findings were obtained from low-dose edoxaban. Compared with warfarin, high-dose (low-dose) edoxaban led to an ICER of US$4,917(US$2,294). Multivariate probabilistic sensitivity analysis showed that both high- and low-dose edoxaban has 100% probability of being cost-effective compared to warfarin using 50,000 USD per QALY gained.

CONCLUSIONS: This study showed that once-daily edoxaban (60 mg/30 mg dose-reduced) regimen appears to be a dominant or highly cost-effective treatment relative to rivaroxaban (20mg/15mg dose-reduced) for stroke prevention in AF in Hong Kong.