The impact of criminal justice involvement on HIV transmission dynamics among young Black men who have sex with men: An agent-based network model
Anna Hotton, Aditya Khanna, Babak Mahdavi Ardestani, Leo Wilton, Russell Brewer, Nicholson Collier, Jonathan Ozik, Kayo Fujimoto, Nina Harawa, John SchneiderBackground: In the U.S., Black men who have sex with men (MSM) continue to experience disproportionate rates of new HIV diagnoses and relatively stable incidence in the absence of differences in individual-level behavior. This is likely due to a complex interplay of factors such as incarceration, violence, and socioeconomic marginalization that impact engagement in HIV prevention and care continua. Thus, biomedical prevention will likely need to be combined with structural interventions to end the HIV epidemic among Black MSM. Understanding the impact of criminal justice involvement (CJI) on HIV transmission among Black MSM is important given their disproportionate representation among those incarcerated and the potential impact of CJI on social and sexual networks, employment, housing, and medical care. Guidance is needed to determine which interventions for CJI populations can have the most impact. However, logistical and ethical challenges to empirical research in this context and the complex mechanisms by which CJI likely impacts HIV risk and HIV care limit purely empirical approaches to prioritizing interventions. Agent-based network models (ABNM) can provide insights about emergent dynamics resulting from the intersection of CJI-related changes in network composition and HIV prevention/care continuum engagement, and can provide a virtual platform to facilitate intervention evaluation.
Methods: We developed an ABNM of 10,000 agents representing Black MSM ages 18-34 in the city of Chicago to examine the impact of CJI on HIV incidence among Black MSM by incorporating rules for sexual network and care continuum disruption due to CJI, in addition to biological and behavioral parameters. Exponential random graph models were used to model network formation and dissolution dynamics using the statnet suite of packages in R. Other ABNM components, including CJI interventions, were developed with the Repast HPC ABM toolkit using C++. Parameter values for sexual behaviors, network characteristics, engagement in prevention/care continua, and incarceration incidence were calculated from a population-based cohort study of young Black MSM in Chicago and calibrated to local HIV incidence and prevalence estimates.
Anticipated outputs: Initial modelling will quantify network and care continuum disruption associated with CJI and examine the extent to which these mechanisms impact 10-year HIV incidence and prevalence trajectories individually and in combination. Planned experiments will then quantify the impact of CJI-related interventions on these trajectories among Black MSM. We will evaluate the relative impact of interventions to reduce 1.) incidence of incarceration and recidivism (e.g., criminal justice policy reform), and 2.) post-release disruption in HIV care (e.g., interventions to facilitate care engagement by reducing insurance, housing, or employment barriers). We will also explore the utility of targeting HIV pre-exposure prophylaxis (PrEP) and anti-retroviral treatment interventions to CJI individuals and their networks.
Implications: Our findings may guide efficient allocation of limited intervention resources by quantifying the impact of CJI on HIV incidence through network and care continuum disruption and by evaluating the effects of potential combinations of interventions on HIV. Future efforts will incorporate other structural drivers of incarceration and HIV in the model and expand the scope of evaluation of biomedical and socio-structural interventions.