Simulating system dynamics of the HIV care continuum to achieve treatment as prevention.

The continuing HIV pandemic calls for broad, multi-sectoral responses that foster community control of local prevention and care services, with the goal of leveraging high quality treatment as a means of reducing HIV incidence. Service system improvements require stakeholder input from across the care continuum to identify gaps and to inform strategic plans that improve HIV service integration and delivery. System dynamics modeling offers a participatory research approach through which stakeholders learn about system complexity and about ways to achieve sustainable system-level improvements. Via an intensive group model building process with a task force of community stakeholders with diverse roles and responsibilities for HIV service implementation, delivery and surveillance, we designed and validated a multi-module system dynamics model of the HIV care continuum, in relation to local prevention and care service capacities. Multiple sources of data were used to calibrate the model for a three-county catchment area of central Connecticut. We feature a core module of the model for the purpose of illustrating its utility in understanding the dynamics of treatment as prevention at the community level. We also describe the methods used to validate the model and support its underlying assumptions to improve confidence in its use by stakeholders for systems understanding and decision making. The model's generalizability and implications of using it for future community-driven strategic planning and implementation efforts are discussed.

The Impact of Perceptions of Community Stigma on Utilization of HIV Care Services.

The relationship between perceived community stigma and treatment adherence has been established in previous literature. Yet, less is known about explicit circumstances in which perceived community stigma deters people living with HIV (PLWH) from maintaining care. This research examines the impact of perceived community stigma against PLWH on self-reported barriers and supports to remain in HIV care services. We used survey data from a 3-year study of the HIV test and treat (T&T) continuum of services in Hartford, CT, surveying 200 PLWH. Logistic regression was used to determine if perceived community stigma had a statistically significant effect on the willingness of PLWH to utilize HIV care services. Results revealed that an increase in perceived stigma predicted willingness to see a doctor in 6 months for those who 'had a fear of poor treatment' (χ2(6) = 21.995, p < 0.001) and 'were concerned about privacy' (χ2(6) = 16.670, p < 0.01). An increase in perceived stigma was also a significant factor in the belief that supportive case managers helped with accessing HIV care services (χ2(1) = 6.817, p < 0.01). Our findings suggest that having a high degree of perceived community stigma is impactful in instances where individuals anticipate stigma or discrimination.

Using Participatory System Dynamics Modeling to Examine the Local HIV Test and Treatment Care Continuum in Order to Reduce Community Viral Load.

Achieving community-level goals to eliminate the HIV epidemic requires coordinated efforts through community consortia with a common purpose to examine and critique their own HIV testing and treatment (T&T) care system and build effective tools to guide their efforts to improve it. Participatory system dynamics (SD) modeling offers conceptual, methodological, and analytical tools to engage diverse stakeholders in systems conceptualization and visual mapping of dynamics that undermine community-level health outcomes and identify those that can be leveraged for systems improvement. We recruited and engaged a 25-member multi-stakeholder Task Force, whose members provide or utilize HIV-related services, to participate in SD modeling to examine and address problems of their local HIV T&T service system. Findings from the iterative model building sessions indicated Task Force members' increasingly complex understanding of the local HIV care system and demonstrated their improved capacity to visualize and critique multiple models of the HIV T&T service system and identify areas of potential leverage. Findings also showed members' enhanced communication and consensus in seeking deeper systems understanding and options for solutions. We discuss implications of using these visual SD models for subsequent simulation modeling of the T&T system and for other community applications to improve system effectiveness.