Welcome to SIU Medicine Department of Population Science and Policy (PSP). Our work expands SIU Medicine’s reach into the spaces where people live, work, learn and play. PSP focuses on improving a community’s social determinants of health through research, intervention and policy change. PSP consists of three divisions: The Epidemiology and Biostatistics Division gathers and analyzes data, Human and Community Development collaborates with communities to identify and implement solutions to improve health through mixed methods research, and Health System Science uses evidence-based research to inform and improve policies that affect the health of populations. PSP is working to move the dial on health in some of Illinois’ unhealthiest communities.