Cost-effectiveness analysis of HIV pre-exposure prophylaxis in Japan

BACKGROUND: While global efforts have been made to prevent transmission of HIV, the epidemic persists. Men who have sex with men (MSM) are at high risk of infection. Despite evidence of its cost-effectiveness in other jurisdictions, pre-exposure prophylaxis (PrEP) for MSM is neither approved nor reimbursed in Japan. METHOD: The cost-effectiveness analysis compared the use of once daily PrEP versus no PrEP among MSM over a 30-year time horizon from a national healthcare perspective. Epidemiological estimates for each of the 47 prefectures informed the model. Costs included HIV/AIDS treatment, HIV and testing for sexually transmitted infections, monitoring tests and consults, and hospitalization costs. Analyses included health and cost outcomes, as well as the incremental cost-effectiveness ratio (ICER) reported as the cost per quality-adjusted life year (QALY) for all of Japan and each prefecture. Sensitivity analyses were performed. FINDINGS: The estimated proportion of HIV infections prevented with the use of PrEP ranged from 48% to 69% across Japan, over the time horizon. Cost savings due to lower monitoring costs and general medical costs were observed. Assuming 100% coverage, for Japan overall, daily use of PrEP costs less and was more effective; daily use of PrEP was cost-effective at a willingness to pay threshold of ¥5,000,000 per QALY in 32 of the 47 prefectures. Sensitivity analyses found that the ICER was most sensitive to the cost of PrEP. INTERPRETATION: Compared to no PrEP use, once daily PrEP is a cost-effective strategy in Japanese MSM, reducing the clinical and economic burden associated with HIV.