Examining System Dynamics Affecting HIV Community Viral Load

This 3-year study will investigate the HIV test & treat (T&T) continuum of services in Greater Hartford, CT to examine the “treatment cascade.” This refers to people with HIV (PWH) not getting tested to know their status or not getting linked to care and getting on and staying on antiretroviral therapy (ART) in order to achieve viral suppression. PWH who have not achieved viral suppression are more likely to transmit HIV to others, which adds to the total amount of virus in the community, or “community viral load” (CVL). This study is designed to engage multiple community stakeholders, including both providers and PWH, to develop a comprehensive system dynamics model that can be used to understand how systemic processes affect HIV CVL by interrupting the T&T continuum of services and contributing to the treatment cascade. The study aims are: (1) identify inter-organizational network factors that affect the ability of PWH to move efficiently and effectively across the T&T continuum; (2) examine the personal, inter-organizational, and community level factors that interact to generate system dynamics in the movement of PWH through the T&T continuum; and (3) based on these results, develop a conceptual system dynamics model (visual representation) that integrates the inter-organizational network and system dynamics structural factors and processes that collectively impede progress toward reducing CVL. The goal is to be able to use this model, and the new systems understanding of the treatment cascade, to build systemic interventions to reduce HIV CVL to prevent further spread of the virus.

Additional Information:

Margaret R. Weeks, Ph.D.
Principal Investigator

Jianghong Li, MD, MSc.

Heather Mosher, Ph.D.

Maryann Abbott, M.A.
Project Director

Danielle Green, Ph.D.
Research Associate

Lucy Rohena
Outreach Interviewer

Rosely Gonzalez
Outreach Interviewer

Albert Einstein School of Medicine of Yeshiva University:
David Lounsbury, Ph.D.

This 3-year case study will examine factors that affect efforts to reduce the HIV epidemic at the community level through the promotion of testing and treatment (T&T). The T&T strategy was designed to reduce HIV viral load (VL) to undetectable in all infected persons, thereby lowering each person’s infectivity and community viral load (CVL), in order to prevent new cases. These efforts have generated new attention to the problem of people with HIV (PWH) dropping off the T&T continuum before achieving undetectable VL, known as the treatment cascade. Despite multi-sector efforts to tackle it, the HIV epidemic endures because it is complex, embedded in a dynamic system of inter-organizational network structures and interacting social and personal forces that generate non-linear processes affecting efforts to curb the epidemic. It is necessary to unpack these structures and dynamics, identify a scientifically based design to organize service networks, and build “systemic interventions” to achieve better results. Systems science methodologies such as social network analysis, system dynamics modeling, and mixed methods ethnography offer both a conceptual framework and analytical tools to achieve these goals. These systems science methods make it possible to understand the dynamic processes that characterize the treatment cascade from the perspectives and experiences of those directly involved in it at multiple levels of the system. This study has the following aims: (1) Identify inter-organizational network factors (density of linkages, centralization/fragmentation, bridges, bottlenecks, quality of relations) that affect efficient and effective progression of PWH across the T&T continuum by constructing a whole network diagram of local T&T service organizations; (2) Examine the individual, inter-organizational, and community socio-structural factors that generate non-linear system dynamics (time lags, interruptions, positive/ negative feedback, acceleration, reversals) characterizing transitions of PWH through the stages of the T&T continuum using mixed methods to specify, contextualize, and track experiences of PWH and providers over time; and (3) Based on the results of examination of T&T network and systems properties and dynamics, develop an explanatory framework represented by a conceptual SD model that integrates organizational network and SD structural factors and processes that collectively impede progress toward reducing CVL. The study will be conducted in the high prevalence area of metropolitan Hartford, CT, a typical mid-sized, northeast city. Mixed data collection methods (qualitative interviews, inter-organizational network diagramming/analysis, longitudinal cohort survey, case tracking, group elicitation for systems model development and refinement) will be used to elicit perspectives and experiences of PWH and providers across the T&T continuum. Findings will provide an analytically generalizable SD conceptual model of the treatment cascade that can be tested, validated, and replicated in subsequent research. The rich data and the conceptual model also have immediate application value for local stakeholders to develop improved strategies to mitigate the treatment cascade.