摘要：Population health is a relatively new term that has not yet been precisely defined. Is it a concept of health or a field of study of health determinants? We propose that the definition be “the health outcomes of a group of individuals, including the distribution of such outcomes within the group,” and we argue that the field of population health includes health outcomes, patterns of health determinants, and policies and interventions that link these two. We present a rationale for this definition and note its differentiation from public health, health promotion, and social epidemiology. We invite critiques and discussion that may lead to some consensus on this emerging concept. ALTHOUGH THE TERM “population health” has been much more commonly used in Canada than in the United States, a precise definition has not been agreed upon even in Canada, where the concept it denotes has gained some prominence. Probably the most influential contribution to the development of the population health approach is Evans, Barer, and Marmor’s Why Are Some People Healthy and Others Not? The Determinants of Health of Populations , 1 which grew out of the work of the Population Health Program of the Canadian Institute for Advanced Research. No concise definition of the term appears in this volume, although its authors state the concept’s “linking thread [to be] the common focus on trying to understand the determinants of health of populations.” 1(p29) The idea that population health is a field of study or a research approach focused on determinants seems to have evolved from this work. Early discussions at the Canadian Institute for Advanced Research also considered the definition and measurement of health and the processes of health policymaking, but the dominant emphasis evolved to the determinants themselves, particularly the nonmedical determinants. John Frank, the scientific director of the recently created Canadian Institute of Population and Public Health, has similarly called population health “a newer research strategy for understanding the health of populations.” 2 T. K. Young’s recent book Population Health also tends in this direction; he states that in Canada and the United Kingdom in the 1990s, the term has taken on the connotation of a “conceptual framework for thinking about why some populations are healthier than others as well as the policy development, research agenda, and resource allocation that flow from this framework.” 3(p4) However, Young also indicates that in the past, the term has been used as a “less cumbersome substitute for the health of populations,” which is of course its literal meaning. Evans and Stoddart, while supporting an emphasis on “understanding of the determinants of population health,” have also stated, however, that “different concepts [of health] are neither right or wrong, they simply have different purposes and applications. . . . [W]hatever the level of definition of health being employed, however, it is important to distinguish this from the question of the determinants of that definition of health.” 1(p28) The Health Promotion and Programs Branch of Health Canada has recently stated that “the overall goal of a population health approach is to maintain and improve the health of the entire population and to reduce inequalities in health between population groups.” 4(p1) They indicate that one guiding principle of a population health approach is “an increased focus on health outcomes (as opposed to inputs, processes, and products) and on determining the degree of change that can actually be attributed to our work.”(p11) Dunn and Hayes, quoting the definition of the Canadian Federal/Provincial/Territorial Advisory Committee on Population Health, write that “population health refers to the health of a population as measured by health status indicators and as influenced by social, economic, and physical environments, personal health practices, individual capacity and coping skills, human biology, early childhood development, and health services. As an approach, population health focuses on interrelated conditions and factors that influence the health of populations over the life course, identifies systematic variations in their patterns of occurrence, and applies the resulting knowledge to develop and implement policies and actions to improve the health and well being of those populations.” 5(p57) Kindig has suggested a similarly broad definition: population health is “the aggregate health outcome of health adjusted life expectancy (quantity and quality) of a group of individuals, in an economic framework that balances the relative marginal returns from the multiple determinants of health.” 6(p47) This definition proposes a specific unit of measure of population health and also includes consideration of the relative cost-effectiveness of resource allocation to multiple determinants. Recently, even in the United States, the term is being more widely used, but often without clarification of its meaning and definition. While this development might be seen as a useful movement in a new and positive direction, increased use without precision of meaning could threaten to render the term more confusing than helpful, as may already be the case with “community health” or “quality of medical care.” For this reason, we propose a definition that may have a more precise meaning for policymakers and academics alike; our purpose is to stimulate active critiques and debate that may lead to further clarification and uniformity of use.
