Evaluating the effect of social mobility on the incidence of HIV/AIDS in low-income populations: A dynamic microsimulation study with large cohort data

The control of the HIV/AIDS epidemic remains a significant challenge for public health in Brazil, a country marked by profound social inequalities. In this study, we aimed to use the integration of large data analyses with microsimulation models to evaluate the effect of alternative income-based social mobility policies on AIDS incidence, both in the overall population and in specific vulnerability groups. We created a dynamic microsimulation model of a cohort of 1 million individuals starting from a large dataset of low-income people in 2012 in Brazil, integrated with input parameters from the analysis of a large retrospective cohort of 28.3 million individuals. We incorporated national, subnational, and municipal-level demographic, social and economic changes into the population, and simulated the impact until 2030 of five different scenarios of income social mobility based on income quintiles. A high-coverage, income-based social mobility intervention could reduce the overall incidence of AIDS by 11.8% (IRR 0.88, 0.81-0.96) by 2030. Among people living in extreme poverty, the reduction could reach 24% (IRR 0.76, 0.56-0.96). For those with no or limited literacy, a 17.9% (IRR 0.81, 0.62-1.03) decrease in AIDS incidence could be achieved, while the Black population could see a 12.4% (IRR 0.87, 0.42-1.24) reduction. Income-based social mobility policies could significantly reduce AIDS incidence in low-income populations, particularly in the most vulnerable individuals. These policies should be considered an important strategy for achieving the Sustainable Development Goal of ending AIDS by 2030 in Low- and Middle-Income Countries.