From Volume- to Value-Based Care: Leading Population Health Initiatives October 2016 318 Nurse Leader Claire M. Zangerle, MSN, MBA, RN, Drew A. Harris, DPM, MPH, Holly Rimmasch, RN, MSN, and Geralyn Randazzo, MS, RN, NEA-BC T he evolution of traditional health care delivery from volume based to value cen- tric has elevated population health to a level that has captured the attention of health care leaders. It is the term population health that stymies clinicians, academicians, policy makers, and consumers. They all struggle with a clear meaning or specific defini- tion of the term. Further, those charged to deliver a program in their particular setting are uncertain of what population health is. Varyingly described, pop- ulation health has many faces, including the health of populations, the distribution of health outcomes, and factors that influence the health of populations over a lifetime.