Cost‐effectiveness of hepatitis C virus (HCV) elimination strategies among people who inject drugs (PWID) in Tijuana, Mexico

BACKGROUND AND AIMS In Latin America, Mexico was first to launch a hepatitis C virus (HCV) elimination strategy, where people who inject drugs (PWID) are a main risk group for transmission. In Tijuana, HCV seroprevalence among PWID is >90% with minimal harm reduction (HR). We evaluated cost-effectiveness of strategies to achieve the incidence elimination target among PWID in Tijuana. METHODS Modelling study using a dynamic, cost-effectiveness model of HCV transmission and progression among active and former PWID in Tijuana, to assess the cost-effectiveness of incidence elimination strategies from a healthcare provider perspective. The model incorporated PWID transitions between HR stages (no HR, only opioid agonist therapy, only high coverage needle-syringe programs, both). Four strategies that could achieve the incidence target (80% reduction by 2030) were compared with status quo (no intervention). The strategies incorporated the number of direct-acting antiviral (DAA) treatments required with: 1) no HR scale-up, 2) HR scale-up from 2019 to 20% coverage among PWID, 3) HR to 40% coverage 4) HR to 50% coverage. Costs (2019 US$) and health outcomes (disability-adjusted life years [DALYs]) were discounted 3%/year. Mean incremental cost-effectiveness ratios ([ICER] $/DALY averted) were compared with one-time per capita GDP ($9,698 in 2019) and purchasing power parity-adjusted per capita GDP ($4,842-13,557) willingness-to-pay (WTP) thresholds. RESULTS DAAs alone were the least costly elimination strategy ($173M [95%CI 126M-238M]) but accrued fewer health benefits compared with strategies with HR. DAAs+50% HR coverage among PWID averted the most DALYs, but cost $265M [95%CI 210M-335M]. The optimal strategy was DAAs+50% HR (ICER $6743/DALY averted compared to DAAs only) under the one-time per capita GDP WTP ($9,698). CONCLUSIONS A combination of high-coverage harm reduction and hepatitis C virus (HCV) treatment is the optimal cost-effective strategy to achieve the HCV incidence elimination goal in Mexico.