Abstract for: Participatory Systems Thinking to Inform Implementation Pathways for PrEP: Early Insights from a Co-Design Process in Switzerland

Despite strong evidence for PrEP effectiveness, access remains constrained by specialized clinical settings, complex monitoring requirements, and structural barriers including cost, stigma, and administrative burden. In Switzerland, the SwissPrEPared program has expanded access, but may create bottlenecks limiting reach. This study explores how participatory systems thinking can identify capacity constraints emerging after insurance reform and support program redesign and governance in HIV prevention. Using community-based system dynamics and participatory implementation system mapping, we conducted three co-design workshops and five interviews (January–March 2025) with 23 participants, including PrEP users, healthcare providers, and program administrators, across multiple languages. Activities included mapping service pathways, identifying barriers and enabling conditions, and generating recommendations. A follow-up survey is currently refining and validating emerging causal themes. Workshops identified recurring themes, including flexible counseling pathways, decentralized service delivery, expanded provider workforce, simplified administration, and inclusive messaging. These suggest reinforcing and balancing processes linking service accessibility, stigma, provider capacity, and uptake. Initial synthesis reveals dynamic relationships between policy design, health system structure, and community engagement that shape PrEP access, with preliminary causal propositions presented in Figure 1. Figure 1 illustrates co-designer-generated causal themes currently under survey refinement. Next steps include deepening systems analysis, validating causal relationships, exploring leverage points, and engaging PrEP experts in implementation-focused workshops. This work contributes to system dynamics by demonstrating how participatory approaches can support public health program governance, applying systems thinking to HIV prevention, and integrating community co-design with formal system modeling. AI-assisted tools, including DeepL and Grammarly, were used to support the structural reformatting, translation, and grammatical refinement of this abstract.