Population Health in Canada: A Working Paper

V. Definitional Issues in Health and Social Impact Assessments for Popualtion Health

Before program planners and policy makers from different sectors can share responsibility for action on the determinants of health they must have some degree of consensus in their understanding of key concepts and terms. Adoption of a population health approach to policy and program decision-making in the absence of an explicit conceptual model of health has the potential to focus only on parts of the problem. Models of population health, without an "explicit" supporting text detailing their policy-intended implications, have the potential to be misunderstood and misused. Before discussing key issues such as shared responsibility, accountability and impact assessment, it is important to define key terms. Agreement upon key terms in the population health literature has been problematic thus far, however.

Health

By its very nature, the population health movement defines improvements in health as a desired outcome. However, the definition and measurement of health remains problematic. The Dictionary of Epidemiology lists several definitions of health, including "a state of equilibrium between humans and the physical, biologic and social environment, compatible with full functional activity." This definition moves beyond the idea that health equals primarily the absence of disease.

The European Region of WHO defines health to be

"the extent to which an individual or group is able on the one hand to realize aspirations and satisfy needs, and, on the other hand, to change and cope with the environment. Health is therefore seen as a resource for everyday life, not the objective of living; it is a positive concept emphasizing social and personal resources as well as physical capacities."

We also note the definition of health offered by Rootman and Raeburn (1994) that additionally incorporates environmental and policy components:

"Health...has to do with the bodily, mental, and social quality of life of people as determined in particular by psychological, societal, cultural, and policy dimensions. Health is...to be enhanced by sensible lifestyles and the equitable use of public and private resources to permit people to use their initiative individually and collectively to maintain and improve their own well-being, however they may define it. (p. 69)"

Definitions of health, such as some of those identified above, have been criticized as hopelessly utopian and unfeasible in their apparent blurring of distinctions between health and social development. They appear to identify virtually all human activity as health-related and equate all human and social values as health (Berlin, 1990; Crawford, 1977; Strong, 1986). A major difficulty with such definitions is that no limits are placed on what is encompassed by health, which other sectors may view as a form of "health imperialism." Without parameters for planning, policy, expenditure, practice, or science, the scope of the population health field, and therefore its expenditures, appear unbounded (Labonté, 1994; Rootman and Raeburn, 1994).

Definitions of health that encompass the determinants of health also mix cause and effect, thereby making it difficult to use that concept of health as an outcome variable. Such breadth of definition makes health indistinguishable from its determinants and therefore un-measurable as the consequence of those determinants or the programs and policies designed to modify the determinants.

In 1940, the World Health Organization (WHO) described health as the "state of complete physical, emotional, and social well-being, not merely the absence of disease or infirmity" Evans and Stoddart (1994) criticized the WHO's early definition of health, stating that it is "difficult to use as the basis for health policy, because implicitly it includes all policy as health policy" (p. 28). Their population health framework differentiates between disease, health and function (as experienced by the individual) and well-being (the sense of life satisfaction of the individual). (See Appendix B for a discussion of population health frameworks and models)

In the end, we offer a definition of health as "the capacity of people to adapt to, respond to, or control life's challenges and changes (Frankish et al., 1996). That is, health has an instrumental value rather than an end in itself (Green and Kreuter, 1991). Health is also intimately tied to personal circumstances that, in turn, are tied to social, cultural, economic and environmental influences.

The population health perspective has often depended upon implicitly shared meanings among researchers and policy makers to facilitate discourse. While it acknowledges that health is more than merely the absence of disease, consensus as to the definition and measurement of health outcomes has not been achieved. Generally, population health research has taken the dependent variable (health outcomes) somewhat for granted and made do with available measures (morbidity or mortality statistics, or self-rated health status, for example) in statistical analysis, in part because of their availability. This can be interpreted as a weakness, since clear and concise definitions are an essential part of a scientific enterprise and different aspects of a broad health concept may be differently related to determinants. It can also be viewed as a strength, however, for the reasons cited above.

Program planners and policy makers engaged in population health activities seek to produce and measure the impact of their specific programs and policies. To do so, they must identify the "dependent variables" of population health. It is likely that there will be multiple desired outcomes. It is also likely that stakeholders from different parts of government or society (e.g., the private sector) may have differing perspectives as to how complex concepts such as health, well-being and quality-of-life can, or should be, operationally defined and measured. For example, recent experience in the development of BC's provincial health goals suggests that representatives of the business sector had great difficulty in seeing broad determinants of health such as poverty or education as a legitimate concern of the health sector.

Definition of Population and Population Health

In everyday usage, "population" refers to the number of people in a given area. This can be defined geographically or politically, as in a country, although physical boundaries are not always necessary, as when referring to groups of people sharing common characteristics (e.g. ethnicity, religion) who are scattered throughout a particular geographical or political unit" (Young, 1998:3). The population health perspective uses this understanding of population, in contrast with the concept of population in statistics.

Population health has been variously defined as:

"the epidemiological and social condition of a community (defined by geography or by common interests) that minimizes morbidity and mortality, ensures equitable opportunities, promotes and protects health, and achieves optimal quality of life (Frankish et al., 1996).

"the health of a population as measured by health status indicators and as influenced by social, economic, and physical environments, personal health practices, individual health capacity and coping skills, human biology, early childhood development and health services. (FPT Advisory Committee on Population Health, 1997).

Population health research is concerned with whole communities or populations, not just individuals or risk groups; generally more distal rather than proximal determinants of health; greater intersectoral action beyond only the health sector; and making populations more self-sufficient and less dependent on health services and professionals. The population health perspective is concerned with explaining differences in health across population groups, and has the intent of doing so at the population rather than individual level (McGrail et al., 1998:3). It describes the analysis of major social, behavioural and biological influences upon overall levels of health status within and between identifiable population groups and subgroups (Hayes and Dunn, 1998:7) and generally looks beyond health care to the social world for causal variables. That is, it attempts to identify aspects of the social and cultural milieu (Corin, 1994:93) that affect differences in health status. Population health research has four broadly defined goals, then: to describe, to explain, to predict and to control (Young, 1998:6).

Determinants of Health

It is now 25 years since notions regarding determinants of health were introduced in Canadian health policy in the form of the "health field" concept." Lalonde (1974) identified four elements of the health field: lifestyle, environment, human biology, and the health care organization The Lalonde Report provided an early glimpse of Canadians' awareness of the contribution of determinants of health involving more than simply the health care system proper (Laframboise, 1973; Lalonde, 1974). This view was further explicated in the "prerequisites for health" seen in the Ottawa Charter for Health Promotion and the "expanded" health field concept offered by Raeburn and Rootman (1989). The Ottawa Charter recognized the fundamental conditions and resources for health to be peace, shelter, education, food, income, a stable ecosystem, sustainable resources, social justice and equity

Together, these documents recognize the role of public policy, society, culture and environment, health services, community/social support and personal behaviours and skills as determinants of health. They also presage current interest in health and social impact assessments by arguing for measurable "health outputs" including morbidity/mortality, positive health indicators, subjective perceptions and aspects of functional capacity or coping

More recently, Evans and Stoddart and their colleagues in the Canadian Institute of Advanced Research (CIAR) have suggested that a number of factors should be recognized as determinants of health. These range from "particular targeted health care services, through genetic endowment of individuals, environmental sanitation, adequacy and quality of nutrition and shelter, stress and the supportiveness of the social environment, to self-esteem and sense of personal adequacy or control." (Evans and Stoddart, 1994:41). An Ontario framework (Ontario Premier's Council on Health Strategy, 1991) conceptualizes the determinants of health in terms of four domains: social environment, physical environment, individual responses and productivity and wealth, where the social environment includes health care, work and (un)employment, social networks, and prenatal/early childhood conditions. The Federal, Provincial, and Territorial Advisory Committee on Population Health (1994) has adopted these and other determinants as the targets for the refocused national and provincial strategies for population health.

The evidence as to the role of each of the determinants of health is complex and multi-faceted. Brief observations regarding some major determinants are offered below.

• Income and social status are among the most important individual-level determinants of health, and health status appears to improve at each step of the income and social hierarchy. For example, there appears to be a smooth gradient between socioeconomic status, measured by one or all of education, income and occupational prestige, and health status among individuals in the western world. Disease is thought to be the pathway to ill health rather than the cause (Evans 1994:6) and some aspect of people's place within the social hierarchy is thought to be the more primary cause (Evans, 1994:7). Hierarchy may influence the development of disease, and other aspects of ill health, through stress and the immune system's ability to cope with stress (Evans, 1994:12) and through the degree of control people have over life circumstances and, hence, their capacity to take action (Hamilton and Bhatti, 1996:5). The indicators of SES are related to one another as well; for example, education increases opportunities for employment.

• Social support networks, including support from families, friends and communities, are associated with better health of individuals. That is, the greater the amount of support available to individuals the better their health. These networks may help people deal with difficult situations and maintain a sense of mastery over life circumstances (Hamilton and Bhatti, 1996:5).

• Those with more control over their work circumstances and fewer stress-related demands of the job are healthier. Workplace injuries and unemployment are also significant causes of health problems. A personal sense of control in environments outside of the workplace is also thought to be related to health, but a recent synthesis of the literature suggests the relationship is not strong (McGrail et al., 1998).

• The genetic endowment of the individual, the functioning of various body systems, and the processes of development and aging are determinants of health. It is thought that many diseases in late life are attributable to influences in fetal and early childhood development through changes in body composition (McGrail et al., 1998:31).

• Personal health practices (lifestyle attributes such as diet, smoking, exercise and substance abuse, for example) and coping skills are relevant influences on health, as are aspects of the social environment that foster them

• Physical factors in the social environment are determinants of health, such as housing and community and road design. Urban violence is related to health (Patrick and Wickizer, 1995) as is pollution of the physical environment (air and water quality, for example), although Hertzman et al. (1995:22) suggest that the social environment has a greater impact on health than does the physical environment.

• Societies which are reasonably prosperous and have an equitable distribution of wealth have the healthiest populations, regardless of the amount they spend on health care. Wilkinson (1996) argues that relative income - the equity of wealth distribution within nations - is more important for health than is the overall wealth of nations. Kawachi et al. (1997) found a strong relationship between income inequality and health among the American states. In Canada, the relationship between income inequality and health status may be moderated by economic and health systems. This could be a function of the fact that Canadian society is more equitable than is the United States; the provinces are more equal than most states with respect to the distribution of income.

• "Social capital is quickly gaining attention as a prominent determinant of health" (McGrail et al., 1998:79), where social capital is understood to be a social resource lodged in the interactional structure of a community and may include the density and type of interaction, norms of commitment and reciprocity, trust and civic engagement. Kawachi et al. (1997) argue that social capital mediates the relationship between income inequality and poor health status, in the United States. Veenstra (1999) found that individual-level attributes of social capital -- trust, commitment, civic and associational participation, for example - are unrelated to self-rated health status in Saskatchewan. The case has yet to be made, therefore, for the importance of social capital to health in Canada.

• Health services are a determinant of health, including the accessibility of preventative and primary care services and immunization and health education programs. In current population health documents health services are often portrayed as the least important of determinants. However, evidence suggests that for certain populations access to and availability of health services continues to be an important influence on their health. For example the UBC Institute of Health Promotion Research is presently writing a report for Health Canada on the role of the mental health system as a determinant of health in persons with mental illnesses.

It is also important to consider the nature of "choice" in relation to one's life circumstances and exposure to specific determinants of health (Milio, 1986; Ontario Premier's Council on Health Strategy, 1991). Milio (1986) notes: "people with lesser incomes are forced to chooseamong fewer alternatives for coping... and as a result they choose economically accessible, least costly choices (cigarettes, alcohol, high calorie foods)." The "nurturing health" framework on determinants of health, (Ontario Premier's Council on Health Strategy, 1991) argues that when health is viewed as more than strictly derived from individual choice then clear links between (determinants of) health and life circumstances emerge. Rutten (1995) offers further important distinction among life conditions (patterns of resources of an individual or group), life conduct (pattern of behaviours), lifestyle (collective pattern of life conduct), and life chances (structural-based probability of correspondence of lifestyle and life situation).

Program planners and policy makers should note that the conceptualization of "determinants of health" remains problematic. Many categories overlap and the quality of evidence regarding the relationships between specific determinants and specific aspects of health is quite uneven. It remains open to debate as to which of the determinants are most open to intervention and which are most likely to contribute to meaningful improvements in the health and quality of life of Canadians. Questions also arise as to which decision makers from which level of government or society should be responsible (individually or collectively) for action on specific determinants of health.

Finally, appraisal of existing evidence on the role of each of the determinants of health logically leads to the foci of the National Conference. These include: the need for new or better tools for measuring outcomes related to health and its determinants; and the need for stronger conceptual models and frameworks portraying the interrelations between and among the determinants and health outcomes.

Health Impact Assessment

Challenges in assessing the health and social impact of programs and policies is a key focus of the National Conference. Frankish et al. (1996) define health impact assessment to be "any combination of procedures or methods by which a proposed policy or program may be judged as to the effect(s) it may have on the health of a population." Policies or programs of any nature may directly affect the health of a population, or may indirectly affect their health by altering, influencing, or affecting the determinants of health (Ratner et al., 1998). [Participants will also be provided a copy of Frankish, et al. (1996). Health Impact Assessment as a Tool for Health Promotion and Population Health.]

The health impacts of policies or programs are only one of many consequent impacts which may include economic, social, or environmental impacts. In recognizing the complexity and potentially far-reaching effects of many policies and programs, however, we note that where such activities may potentially have impacts beyond the health field (i.e. economic, social, and environmental fields), assessments should involve intersectoral cooperation and collaboration

In summary, the definition of health is problematic and can be nearly all-encompassing. The number of potential populations are infinite, and the population health perspective, while seeking to predict adverse health outcomes among identified populations, also aims to control or influence these outcomes. To clarify this complicated mandate Hayes and Dunn (1998) differentiate between the population health perspective and population health research, frameworks and approaches to public policy. The population health perspective refers to the discourse in its broadest sense and subsumes the other three. Population health research refers to empirical research whereas population health frameworks refer to explanations of relationships and understandings of social processes that produce observed results. The application of this knowledge - both empirical and theoretical - through public policy is the final category.

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