Project Summary/Abstract Globally, approximately 1.4 million pregnancies are impacted by HIV every year. In Eastern and Southern Africa, nearly a third of women living with HIV initiating ART during pregnancy become lost to follow-up (LTFU) and 29-42% do not maintain viral suppression in the postpartum period. Differentiated service delivery (DSD) is an evidence-based implementation strategy endorsed by the World Health Organization to improve retention and viral suppression for people living with HIV. DSD simplifies and adapts HIV services to meet the needs and preferences of clinically stable clients, allowing for intensification of service delivery to unstable clients who are most in need. However, DSD models for prevention of mother to child transmission of HIV (PMTCT) are lacking and data to guide the adaptation of DSD to PMTCT are scarce. The objective of this K23 research is to adapt, execute and evaluate a DSD model for PMTCT to enhance retention and viral suppression for this population. The central hypothesis is that retention and viral suppression are driven by a complex interplay of individual and contextual factors that affect women differently and shape their preferences for services. PMTCT programs in resource-limited settings can improve outcomes by tailoring service delivery to more accurately and efficiently meet clients’ needs and preferences using a DSD approach. The specific aims are: (1) Determine patient preferences for PMTCT services through a discrete choice experiment with pregnant and postpartum women living with HIV who are retained in care or LTFU, and use these data to identify components for the DSD model; (2) Develop a DSD model for PMTCT and build organizational readiness for implementation, using a human-centered design approach that incorporates stakeholders’ perspectives; (3) Execute a DSD model for PMTCT at one maternal and child health clinic in a resource-limited setting, and evaluate the model’s implementation using the RE-AIM/PRISM framework. This research will take place at the Academic Model Providing Access to Healthcare (AMPATH) in Kenya and utilize the research infrastructure of the East Africa International Epidemiology Databases to Evaluate AIDS (EA-IeDEA) Consortium. In addition to developing new knowledge, this K23 award will support the career development and training of the PI, Dr. John Humphrey, so that he can achieve his career goal. His career goal is to become an independent investigator with expertise in implementation strategies to improve HIV outcomes in resource-limited settings, with a specific focus on PMTCT. His training aims are: (1) Designing optimized implementation strategies using discrete choice methodology and integrating data generated through multi-methods research; (2) Executing and evaluating implementation strategies using implementation frameworks. This K23 will yield an evidence- based DSD model for PMTCT, filling a major gap in the guidelines and literature for this pop...