Describing Total Population Health: A Review and Critique of Existing Units.

Total population health is a key tenet of health care reform efforts, evident in initiatives such as the National Quality Strategy, shifts toward population-based payments, and community benefit requirements for tax-exempt hospitals. Representing total population health in a way that guides best practices and establishes shared accountability for geographic communities, however, remains a challenge in part because of differences in how stakeholders define populations. To better understand the landscape of potential denominators for population health, this study examined a selection of relevant geographic units. The approach included a comprehensive review of health services and public health research literature as well as recent pertinent health policy documents. Units were characterized based on whether they: exhibit "breadth" of coverage across the whole US population; are "accurate" or grounded in health care utilization patterns; are "actionable" with mechanisms for implementing funding and regulation; and promote "synergism" or effective coordination of public health and health care activities. Although other key components of a total population health unit may exist and no single identified unit possesses all of the aforementioned features, several promising candidates were identified. Specifically, healthcare coalitions link health care and public health domains to care for a geographic community, but their connection to utilization is not empiric and limited funding exists at the coalition level. Although Accountable Care Organizations do not uniformly incorporate public health or facilitate coordination across all payers or providers, they represent an effective mechanism to increase collaboration within health care systems and represent a potential building block to influence total population health.