Systems Science Approaches to Visualize, Model, and Explore Stigma's Role in Socially Patterning HIV Risk Among Gay, Bisexual, and Other Men Who Have Sex With Men (GBMSM) in Europe

Abstract

The inequitable and growing prevalence and incidence of HIV in Europe among GBMSM is an enduring characteristic of the HIV epidemic and makes the continent an important geographical region to study from a global health perspective. Stigma is a significant barrier to, or fundamental cause of, limited equity in HIV prevention and treatment. Yet, current framings of HIV risk and interventions may not adequately incorporate how stigma adversely affects GBMSM’s mental health, constrains their social behavior, influences their sexual decision-making, and hinders access to prevention technologies. Developing and enhancing individual-level interventions that require GBMSM to cope with the structural determinants might reduce HIV risk, but only to a limited degree. A mostly unexplored question is: how does the complexity of structural stigmatization of GBMSM's identities influence one's capabilities, freedoms, and motivations to prevent HIV? Such a question studies each of these separately but, more importantly, explores how each intersecting and overlapping process, in tandem, influences HIV risk, and infection. The call for new theoretical and methodological approaches to address the multitude of factors that influence HIV has been around for over a decade. Moreover, computational and statistical modelling of complex and interacting pathways is now a possibility given advances in data visualization, computational power, and analytic approaches. Such new methods include complex systems theory, and agent-based and multi-level modelling. The objective of this dissertation was to portray how HIV risk among European GBMSM is socially patterned by structural stigma (i.e., policies) to improve public health’s conceptualization, estimation, and quantification of stigma’s role in perpetuating HIV. The objective of the dissertation was informed by three specific aims: (1) Specific aim one: to develop a visualization of HIV risk that reflects stigma’s role in the epidemic among European GBMSM using Complex Systems Theory; (2) Specific aim two: to understand to what extent "stigmatizing policies" influence HIV prevalence and other direct and indirect risk factors among European GBMSM in a simulated agent-based model; and (3) Specific aim three: to assess to what extent countries' LGBTQ+ policies interact with downstream individual-level factors to influence GBMSM’s HIV serostatus using real-world European survey data. In aim one, I examined how the elements within the system and their interactions served to (re)produce HIV risk. The visualization indicated that there are numerous overlapping and interacting factors that shape HIV risk, of which policies play an instrumental role. In aim two, I used an agent-based model (ABM) to study an a priori pathway of the complex systems visualization developed in aim one. The ABM indicated that dynamic and interactional processes, in the form of stigmatizing policies, shape homonegativity and sexual behaviors to influence HIV risk and infection. Aim two informed the research question for aim three. For aim three, I used real-world survey data to examine how country-level sexual and gender minority (SGM) policies (e.g., equality laws, anti-discrimination, gender identity protections, etc.) were associated with GBMSM’s HIV status. The multi-level modeling indicated that SGM policies interacted with downstream behaviors and mental health to increase the probability of an HIV positive serostatus. In totality, this dissertation contributed new insights on HIV equity by demonstrating how stigmatizing policies can shape the emergence of HIV risk through its influence on the dynamic and interactional relationships of diverse risk factors.