Isao Kamae1, Yoichiro Hashimoto2, Yukihiro Koretsune3, Norio Tanahashi4, Tatsunori Murata5, Hemant Phatak6, Larry Z Liu7, Ann C Tang8, Peter Feng Wang9, Ken Okumura10. 1. The University of Tokyo, Tokyo, Japan. 2. Kumamoto City Hospital, Kumamoto, Japan. 3. National Hospital Organization, Osaka National Hospital, Osaka, Japan. 4. Saitama International Medical Center, Saitama, Japan. 5. Crecon Medical Assessment Inc, Tokyo, Japan. Electronic address: tatsunori.murata@crecon.jp. 6. US Health Economics and Outcomes Research, EMD Serono, Rockland, MA. 7. Global Health Economics and Outcomes Research and Evidence, Pfizer Inc, and Weill Medical College of Cornell University, New York, New York, USA. 8. Health Economics and Outcomes Research, Bristol-Myers K.K., Tokyo, Japan. 9. Worldwide Health Economics and Outcomes Research, Bristol-Myers Squibb, Princeton, New Jersey. 10. Hirosaki University Graduate School of Medicine, Aomori, Japan.
Abstract
PURPOSE: The aim of this study was to evaluate the cost-effectiveness of apixaban compared with to warfarin, current standard of care, for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in Japan. METHODS: A previously published lifetime Markov model was adapted to evaluate the cost-effectiveness of apixaban compared with warfarin in patients with NVAF in Japan. In the same model, the costs associated with each clinical event and background mortality were replaced with Japanese data. Whenever available, some of the utility parameters were derived from Japanese published literature. Lifetime horizon was selected to evaluate the value of the treatment benefit (stroke prevention) against potential risks (such as major bleedings) among patients with NVAF. Direct medical cost, long-term care cost, and quality-adjusted life years (QALYs) were calculated from the payers' perspective. FINDINGS: Compared with warfarin, treatment with apixaban was estimated to increase life expectancy by 0.231 year or 0.240 QALYs while treatment cost increased by ¥511,692 (US $5117 at an exchange rate of US $1 = ¥100). The incremental cost-effectiveness ratio was ¥2,135,743 per QALY (US $21,357 per QALY). On the basis of the results of the probabilistic sensitivity analysis, when the willingness-to-pay threshold was set at approximately ≥¥2,250,000 (US $22,500) per QALY, the probability of apixaban being cost-effective was ≥50%. Assuming a willingness-to-pay threshold of ¥5,000,000 (US $50,000) and ¥6,700,000 (US $67,000) in Japan, the probability of apixaban being cost-effective was 85% and 91%, respectively. CONCLUSION: Although most participants in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial used for the efficacy data of apixaban in the model were non-Japanese patients, the impact of the limitations on our results was considered small, and our results were deemed robust because of the additional effect in Japanese patients compared with that in the global population according to the subanalysis of Japanese patients in the trial. Therefore, based on an adaptation of a published Markov model, apixaban is a cost-effective alternative to warfarin in Japan for stroke prevention among patients with NVAF.
PURPOSE: The aim of this study was to evaluate the cost-effectiveness of apixaban compared with to warfarin, current standard of care, for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in Japan. METHODS: A previously published lifetime Markov model was adapted to evaluate the cost-effectiveness of apixaban compared with warfarin in patients with NVAF in Japan. In the same model, the costs associated with each clinical event and background mortality were replaced with Japanese data. Whenever available, some of the utility parameters were derived from Japanese published literature. Lifetime horizon was selected to evaluate the value of the treatment benefit (stroke prevention) against potential risks (such as major bleedings) among patients with NVAF. Direct medical cost, long-term care cost, and quality-adjusted life years (QALYs) were calculated from the payers' perspective. FINDINGS: Compared with warfarin, treatment with apixaban was estimated to increase life expectancy by 0.231 year or 0.240 QALYs while treatment cost increased by ¥511,692 (US $5117 at an exchange rate of US $1 = ¥100). The incremental cost-effectiveness ratio was ¥2,135,743 per QALY (US $21,357 per QALY). On the basis of the results of the probabilistic sensitivity analysis, when the willingness-to-pay threshold was set at approximately ≥¥2,250,000 (US $22,500) per QALY, the probability of apixaban being cost-effective was ≥50%. Assuming a willingness-to-pay threshold of ¥5,000,000 (US $50,000) and ¥6,700,000 (US $67,000) in Japan, the probability of apixaban being cost-effective was 85% and 91%, respectively. CONCLUSION: Although most participants in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial used for the efficacy data of apixaban in the model were non-Japanese patients, the impact of the limitations on our results was considered small, and our results were deemed robust because of the additional effect in Japanese patients compared with that in the global population according to the subanalysis of Japanese patients in the trial. Therefore, based on an adaptation of a published Markov model, apixaban is a cost-effective alternative to warfarin in Japan for stroke prevention among patients with NVAF.