Abstract
Population health is an approach to understanding and improving health that focuses on the health of entire populations of people and disparities in health across population groups. Population health complements health care by addressing the multiple causes of health that operate at different levels – including biology, behavior, and social and physical environments. It makes explicit the need for strategies that are grounded in an integrative, multi-level understanding of the causes of health and the mechanisms through which health and health disparities are produced.