Abstract

Introduction HIV prevalence disproportionately affects high-risk populations, particularly female sex workers in Africa. Women and girls engaging in transactional sex (WGTS) face similar health risks from unsafe practices, economic vulnerabilities and stigma. However, they are not recognised.Methods Using existing literature and data from the POWER randomised controlled trial, we developed a deterministic compartmental model to assess HIV dynamics among WGTS, their sugar daddies and low-risk populations. We evaluated the cost-effectiveness of a new structural intervention to prevent HIV among WGTS in urban Cameroon by reducing the financial need to engage in transactional sex in the case of illness and injury shocks to the household. The intervention provided free healthcare to WGTS and their economic dependents through a zero-cost health insurance package. We explored the cost-effectiveness of this intervention considering various population coverage levels (0%, 25%, 50%, 75% and 100%). We calculated the incremental cost-effectiveness ratio (ICER) per disability-adjusted life-year (DALY) and HIV infections averted, employing both univariable and global sensitivity analyses. Probabilistic sensitivity analyses considered all parameters, including the insurance effect in reducing HIV, comparing simulated ICERs to willingness-to-pay thresholds. We also compared the health insurance strategy with expanding pre-exposure prophylaxis (PrEP) coverage. All costs were evaluated in 2023 UK pounds () pound using a 3% discount rate, with Cameroon's gross domestic product (GDP) per capita recorded at 1239 pound.Results Implementing health insurance coverage levels of 25%, 50%, 75% and 100% yielded ICERs/DALY averted of 2795 pound (2483- pound 2824) pound, 2541 pound (2370- pound 2592) pound, 2263 pound (2156- pound 2316) pound and 1952 pound (1891- pound 1998) pound, respectively, compared with 0% coverage. Probabilistic sensitivity analysis indicated an ICER=2128 pound/DALY averted at 100% coverage, with 58% of simulations showing ICERs