Cost-effectiveness of health insurance among women engaged in transactional sex and impacts on HIV transmission in Cameroon: a mathematical model.
Allel K., Cust H., Mfochive I., Szawlowski S., Nitcheu E., Tamgno ED., Moyoum S., Noo J., Billong S., Tamoufe U., Lepine A.
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 (£) using a 3% discount rate, with Cameroon's gross domestic product (GDP) per capita recorded at £1239. RESULTS: Implementing health insurance coverage levels of 25%, 50%, 75% and 100% yielded ICERs/DALY averted of £2795 (£2483-£2824), £2541 (£2370-£2592), £2263 (£2156-£2316) and £1952 (£1891-£1998), respectively, compared with 0% coverage. Probabilistic sensitivity analysis indicated an ICER=£2128/DALY averted at 100% coverage, with 58% of simulations showing ICERs