Chapter 4: Population Health

INTRODUCTION

There is no single, agreed-upon definition about what population health means and no single approach to implementing it. Some define population health broadly to mean taking accountability for a defined patient population in a community; others define it more narrowly in terms of managing wellness. These definitions appear to focus on population health management more than population health.

Two of the pioneers in this area, David Kindig and Greg Stoddart, defined population health as “the health outcomes of a group of individuals, including the distribution of such outcomes within the group.”¹ They further argued that the subject encompasses not only health outcomes, but also the patterns of health determinants and the policies and interventions that link the two. Such policies and interventions might be considered their label for population health management. They view the determinants as independent variables and the outcomes as dependent variables. Their view is depicted in Figure 4-1.

Their definition is close to that popularized by Don Berwick and his colleagues, who defined population health as one angle of the “triple aim” (covered in the next chapter). It includes (1) disease burden (ie, incidence and/or prevalence of major chronic conditions); (2) health outcomes (eg, mortality, health and functional status, and health life expectancy); and (3) behavioral and physiological factors that affect both (1) and (2).²

Following the approach taken by Kindig and Stoddart, this chapter summarizes the evidence base on the health status indicators of the US population (including disease burden, chronic illness prevalence, functional status, and life expectancy), the distribution (including disparities) of health outcomes across the population, and the drivers of health status (behavioral factors, physiological factors, environmental factors, genetic factors). It then reviews some of the approaches that have been taken to managing population health.

HEALTH DISPARITIES IN THE US POPULATION: ACCESS, UTILIZATION, AND HEALTH STATUS

There Is Good News and Bad News

Since the passage of the Patient Protection and Affordable Care Act (PPACA, also known as “Obamacare”) in 2010, all racial and ethnic groups have experienced improvements in health coverage, access, and utilization compared to prior to the PPACA (Figure 4-2).^3,4 Hispanics and Blacks experienced improvements in the largest number of coverage, access, and utilization measures tracked by the Kaiser Family Foundation.⁵ While these improvements helped narrow some disparities in health coverage, access, and utilization, nonelderly Blacks and Hispanics continued to fare worse than Whites across most examined measures after PPACA (Figure 4-3). Nonelderly Asians generally fared similar to Whites across measures. Across racial and ethnic groups, most measures of health status remained stable or improved compared to prior to the PPACA (see Figure 4-3).