Modelling HIV/AIDS epidemiological complexity: A scoping review of Agent-Based Models and their application.

OBJECTIVE: To end the AIDS epidemic by 2030, despite the increasing poverty and inequalities, policies should be designed to deal with population heterogeneity and environmental changes. Bottom-up designs, such as the Agent-Based Model (ABM), can model these features, dealing with such complexity. HIV/AIDS has a complex dynamic of structural factors, risk behaviors, biomedical characteristics and interventions. All embedded in unequal, stigmatized and heterogeneous social structure. To understand how ABMs can model this complexity, we performed a scoping review of HIV applications, highlighting their potentialities. METHODS: We searched on PubMed, Web of Science, and Scopus repositories following the PRISMA extension for scoping reviews. Our inclusion criteria were HIV/AIDS studies with an ABM application. We identified the main articles using a local co-citation analysis and categorized the overall literature aims, (sub)populations, regions, and if the papers declared the use of ODD protocol and limitations. RESULTS: We found 154 articles. We identified eleven main papers, and discussed them using the overall category results. Most studies model Transmission Dynamics (37/154), about Men who have sex with Men (MSM) (41/154), or individuals living in the US or South Africa (84/154). Recent studies applied ABM to model PrEP interventions (17/154) and Racial Disparities (12/154). Only six papers declared the use of ODD Protocol (6/154), and 34/154 didn't mention the study limitations. CONCLUSIONS: While ABM is among the most sophisticated techniques available to model HIV/AIDS complexity. Their applications are still restricted to some realities. However, researchers are challenged to think about social structure due model characteristics, the inclusion of these features is still restricted to case-specific. Data and computational power availability can enhance this feature providing insightful results.

The effects of cash transfer programmes on HIV/AIDS prevention and care outcomes: a systematic review and meta-analysis of intervention studies.

BACKGROUND: Poverty and social inequality are risk factors for poor health outcomes in patients with HIV/AIDS. In addition to eligibility, cash transfer programmes can be divided into two categories: those with specific requirements (conditional cash transfers [CCTs]) and those without specific requirements (unconditional cash transfers). Common CCT requirements include health care (eg, undergoing an HIV test) and education (eg, children attending school). Trials assessing the effect of cash transfer programmes on HIV/AIDS outcomes have yielded divergent findings. This review aimed to summarise evidence to evaluate the effects of cash transfer programmes on HIV/AIDS prevention and care outcomes. METHODS: For this systematic review and meta-analysis, we searched PubMed, EMBASE, Cochrane Library, LILACS, WHO IRIS, PAHO-IRIS, BDENF, Secretaria Estadual de Saúde SP, Localizador de Informação em Saúde, Coleciona SUS, BINACIS, IBECS, CUMED, SciELO, and Web of Science up to Nov 28, 2022. We included randomised controlled trials (RCTs) that evaluated the effects of cash transfer programmes on HIV incidence, HIV testing, retention in HIV care, and antiretroviral therapy adherence, and conducted risk of bias and quality of evidence assessments using the Cochrane Risk of Bias tool and the Grading of Recommendations, Assessment, Development, and Evaluations approach. A random-effects meta-analysis model was used to combine studies and calculate risk ratios (RRs). Subgroup analyses were performed using conditionality types (ie, school attendance or health care). The protocol was registered with PROSPERO, CRD42021274452. FINDINGS: 16 RCTs, which included 5241 individuals, fulfilled the inclusion criteria. Of these, 13 studies included conditionalities for receiving cash transfer programmes. The results showed that receiving a cash transfer was associated with lowered HIV incidence among individuals who had to meet health-care conditionalities (RR 0·74, 95% CI 0·56-0·98) and with increased retention in HIV care for pregnant women (1·14, 95% CI 1·03-1·27). No significant effect was observed for HIV testing (RR 0·45, 95% CI 0·18-1·12) or antiretroviral therapy adherence (1·13, 0·73-1·75). Lower risk of bias was observed for HIV incidence and having an HIV test. The strength of available evidence can be classified as moderate. INTERPRETATION: Cash transfer programmes have a positive effect on mitigating HIV incidence for individuals who have to meet health-care conditionalities and on increasing retention in HIV care for pregnant women. These results show the potential of cash transfer programmes for HIV prevention and care, especially among people in extreme poverty, and highlight that cash transfer programmes must be considered when developing policies for HIV/AIDS control, as indicated by the UNAIDS 95-95-95 target of the HIV care continuum. FUNDING: National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA.

Evaluating the impact of social determinants, conditional cash transfers and primary health care on HIV/AIDS: Study protocol of a retrospective and forecasting approach based on the data integration with a cohort of 100 million Brazilians.

BACKGROUND: Despite the great progress made over the last decades, stronger structural interventions are needed to end the HIV/AIDS pandemic in Low and Middle-Income Countries (LMIC). Brazil is one of the largest and data-richest LMIC, with rapidly changing socioeconomic characteristics and an important HIV/AIDS burden. Over the last two decades Brazil has also implemented the world's largest Conditional Cash Transfer programs, the Bolsa Familia Program (BFP), and one of the most consolidated Primary Health Care (PHC) interventions, the Family Health Strategy (FHS). OBJECTIVE: We will evaluate the effects of socioeconomic determinants, BFP exposure and FHS coverage on HIV/AIDS incidence, treatment adherence, hospitalizations, case fatality, and mortality using unprecedently large aggregate and individual-level longitudinal data. Moreover, we will integrate the retrospective datasets and estimated parameters with comprehensive forecasting models to project HIV/AIDS incidence, prevalence and mortality scenarios up to 2030 according to future socioeconomic conditions and alternative policy implementations. METHODS AND ANALYSIS: We will combine individual-level data from all national HIV/AIDS registries with large-scale databases, including the "100 Million Brazilian Cohort", over a 19-year period (2000-2018). Several approaches will be used for the retrospective quasi-experimental impact evaluations, such as Regression Discontinuity Design (RDD), Random Administrative Delays (RAD) and Propensity Score Matching (PSM), combined with multivariable Poisson regressions for cohort analyses. Moreover, we will explore in depth lagged and long-term effects of changes in living conditions and in exposures to BFP and FHS. We will also investigate the effects of the interventions in a wide range of subpopulations. Finally, we will integrate such retrospective analyses with microsimulation, compartmental and agent-based models to forecast future HIV/AIDS scenarios. CONCLUSION: The unprecedented datasets, analyzed through state-of-the-art quasi-experimental methods and innovative mathematical models will provide essential evidences to the understanding and control of HIV/AIDS epidemic in LMICs such as Brazil.