Social Epidemiology

Social epidemiology is a multidisciplinary area of research that incorporates aspects of sociology, psychology, biology, health, medicine, economics, and political science into the study of the health of individuals and populations. A variety of conceptual frameworks inform the study of social epidemiology including psychosocial, social production of disease, political economy, eco-epidemiology, social ecological, and ecosocial. While social epidemiologists initially used a stress adaptation or risk factor approach to identify characteristics that defined the health of individuals, researchers are now taking a broader look at the evolutionary, social, socioeconomic, political, and institutional policies that create inequalities in health within and among populations.

Keywords Eco-Epidemiology; Ecosocial Theory; Medical Sociology; Population Health; Psychosocial Theory; Social Epidemiology; Social Production of Disease; Social Ecological Systems

Social Epidemiology

Overview

Social epidemiology explores the social phenomena that impact public health. According to Burris (2002), there is a clear distinction between social epidemiologists and others. He explains, "Whereas traditional epidemiologists are trained to ask the question, 'Why are some individuals healthy and others not?' the social epidemiologist is concerned with the question, 'Why are some societies healthy, while others are not?'" (p. 510). Indeed, the development of social epidemiology over the last half of the twentieth century marked a movement from a broad effort to understand social factors related to health toward a more focused study of the social inequalities in health, as they provide a framework for the improvement of population health (House, 2002). In studying the causes of health issues, Krieger (2001) suggests that it "raises not only complex philosophical issues but also…issues of accountability and agency…the central question becomes: who and what is responsible for population patterns of health, disease, and well-being as manifested in present, past and changing social inequalities in health?" (p. 668).

Health Indicators

Research into social patterns that impact health, both positively and negatively, has led social epidemiologists to think outside the box of the biomedical establishment toward macroeconomic indicators such as economic development, poverty, unemployment, and the distribution of resources as well as social indicators such as social cohesion, social exhaustion, gender and racial/ethnic identity. These indicators are determinants of the conditions under which people live and work in order to maintain their health and that impact both daily life and health outcomes (Burris, 2002). Burris, Kawachi, and Sarat (2002) offer economic inequality as an example, stating it "can be seen as a characteristic of social groups at all levels of social organization, from the nation to the neighborhood, and at any level will owe a considerable proportion of its effect to the way it shapes the mundane details of individual interaction in everyday life" (p. 511).

For example, social epidemiology attempts to explain why populations with the same genetic background, lifestyle habits, and access to medical care have widespread variations in overall health. The NiHonSan Study of Japanese immigrants indicated that the subjects were more similar in their health to the people in the US than their Japanese counterparts in Japan (Marmot, Adelstein & Bulusu, 1984 as cited in Burris, Kawachi, and Sarat, 2002). Genetics played only a minor role, and lifestyle factors alone could not account for the differences. Burris, Kawachi, and Sarat (2002) state "one is forced to look toward societal factors to explain why Japanese have better health than Americans, despite smoking more and spending roughly half of what the United States does on medical care" (p. 510).

Lifestyle Choices

In the 1950s and early 1960s, critics, the medical community, and the general public regarded with skepticism the idea that social, psychological, and environmental factors played a key role in overall health. According to House (2002), "though not largely a product of social science research, the US Surgeon General's (1964) report on Smoking and Health gave great impetus to the idea that health and illness were products of individual and social behavior as well as biological processes" (p. 127). For the first time, a lifestyle choice such as smoking was identified as a major risk factor for disease and death. Over time, lifestyle choices such as smoking, drinking, exercising, and eating in moderation, to name a few, were accepted as risk factors for disease by the biomedical and scientific communities and by the public, and they have led to major public policy initiatives supporting health behaviors (DHHS, 1990 as cited in House, 2002). It is now widely accepted that poor health behaviors, lack of social relationships and supports, poor management of chronic stress, and a variety of psychological conditions are major risk factors for individual health (House, 2002).

Population Health

More recently, researchers in the area of social epidemiology have turned their attention away from individual and toward population health issues. Kindig and Stoddart (2003) define population health as "the health outcomes of a group of individuals, including the distribution of such outcomes within the group" (p. 380) and assert that the idea includes not only the health outcomes, but also the patterns of health determinants (risk factors) and the economic and social policies and interventions that impact them. According to Burris, Kawachi, and Sarat (2002), "social epidemiology has made a powerful case that health is determined…by social conditions, including the economy, law and culture. Indeed, at the level of populations, evidence suggests that these ‘structural’ factors are the predominant influences on health" (p. 510). House (2002) concurs, "the rediscovery over the past two decades of social inequalities…in health, especially by socioeconomic status and race/ethnicity…is important…because it provides, conceptually and empirically, a basis for a more integrated, parsimonious, and practically effective science of social factors in health (House, p. 133).

Further Insights

The field of social epidemiology and medical sociology developed rapidly during the second half the twentieth century. Physical health and illness during the 1950s were viewed simply as biological processes by the medical establishment. They were later understood as much more complex functions of social, psychological, and behavioral factors (House, 2002, p. 125). Contemporary social epidemiology is founded upon three theories. Krieger (2001) identifies them as:

• Psychosocial,

• Social production of disease and/or political economy of health, and

• Ecosocial theory and related multi-level frameworks (p. 669).

Each attempts to explain the social inequalities in health; they differ in the emphasis each places on the myriad social and biological factors that shape the health of a population, in the integration of the social and biological factors present, and in their recommendations for further study and action (Krieger, p. 669).

Psychosocial Framework

The psychosocial conceptual framework with which social epidemiology is studied is based upon a model of stress and adaptation that emerged in the 1960s. The framework allowed for the study of the ways in which social and environmental conditions are perceived as stressful and how they then generate behavioral, psychological, and physiological responses. If they exist over a period of time, these responses may lead to chronic health behaviors that negatively impact health such as smoking, drinking, and substance abuse as well as mental and physical illness and, in extreme cases, death (French, Kahn, & Mann, 1962; Lazarus, 1966; McGrath, 1970; Levine & Scotch, 1970 as cited in House, 2002). The extent to which the stressor is viewed as stressful and the ways in which the stressor is responded to are moderated by existing social, psychological, and biological characteristics.

There are a number of identified psychosocial risk factors for health. According to House (2002), these are

• Social relationships and support;

• Acute or event-based stress;

• Chronic stress in work and life; and

• Psychological dispositions such as anger/hostility, lack of self-efficacy/control, and negative affect/hopelessness/pessimism, with new risk factors continuing to be identified (p. 125).

The presence of risk factors is considered within the context of the relationships among them, their causes, and consequences.

One area of application has been the persistent socioeconomic and racial/ethnic disparities in health. A person's socioeconomic position and ethnicity impact the individual's level of exposure to and experiencing of all of the psychosocial risk factors, as well as many of the environmental, biomedical, and genetic risk factors. According to House (2002), the exposure to these combined risk factors offers an explanation of the social disparities in health (p. 125). House posits that if the socioeconomic level of a wide array of disadvantaged members were improved, so would be their health. "This in turn requires better understanding of the macrosocial forces that influence the socioeconomic position of individuals" (House, 2002, p. 125).

In sum, a psychosocial framework focuses upon biological responses to human interactions, or on stress and stressed people in need of psychosocial resources. The framework accords less importance to the origin of the psychosocial risk factors and how their distribution is impacted by social, political, and economic policies, and it leaves open the question of whether the increase in stress levels alone serve as explanation of secular trends in disease and death (Krieger, 2002, p. 670).

Social Production of Disease/Political Economy Framework

The social production of disease and/or political economy of health framework is based upon a risk factor approach to the study of public health. It arose in response to the many theories correlating health with lifestyle choices and asserting that it was the responsibility of individuals to choose to lead lifestyles conducive to good health and to cope better with stress. Krieger (2001) holds that "these new analyses explicitly address economic and political determinants of health and disease, including structural barriers to people living healthy lives" (Doyal, 1979; Conrad & Kerns, 1981; Breilh, 1988 as cited in Krieger, p. 670). The framework centers on the view that governments operate in such a way that the few can accumulate wealth while the masses remain poor, in the broader examination of nations as well as within specified countries. Within such a context, the factors determining health are examined in relation to those who benefit most from specific policies and practice and at whose cost.

The roots of this framework can be found in the original theory proposed by Thomas McKeown (1914-1988) that suggested that the decline in disease mortality in the United Kingdom and the United States during the 19th century was attributable to improved nutrition rather than medical interventions (Krieger, 2001; House, 2002; Burris, 2002). According to House (2002), McKeown demonstrated that the "dramatic advances in life expectancy of the eighteenth, nineteenth, and twentieth centuries occurred prior to either the development of the germ theory of disease or its widespread application via preventive vaccination and pharmacological treatment" (p. 127). Further, despite the enormous advances made in modern medicine, only five of the thirty years' increase in life expectancy in the 20th century U.S. is attributable to the preventive or therapeutic medical practice; most is the result of public health policies, better sanitation, and socioeconomic development activities that resulted in improvements in nutrition, clothing, housing, and household sanitation (Bunker, Frazier & Mosteller, 1994; Preston, 1977; Wilkinson, 1996 as cited in House, 2002). This thesis made social conditions central causes of the health of populations and laid the groundwork for the field of social epidemiology (Link & Phelan, 2001).

Krieger (2001) lists core questions that address how prioritizing capital accumulation over human need affects health, "as evinced through injurious work-place organization and exposure to occupational hazards, inadequate pay scales, profligate pollution, and rampant commodification of virtually every human activity, need, and desire?" (p. 670). The enforcement of state policies also impacts public health in numerous ways. For example, corporate regulation, the real estate market, interest rates, tax codes, trade agreements, labor and environmental legislation, spending on social programs, prisons and the military, and foreign policy agendas all affect public health. In sum, economic and political institutions and decisions that create and support social inequalities in society are also the causes of social inequalities in public health (Krieger, 2001, p. 670).

Access to Resources

Viewed through the lens of "fundamental social causes," this framework supports the idea that as a population develops the ability to avoid disease and death and to prolong life, the individuals who benefit most from that ability are those with more access to more resources of knowledge, money, power, prestige, and beneficial social connections. People with access to fewer of those resources benefit less (Link & Phelan, 2002). These resources are critical to public health in two ways. First, these resources determine the extent to which individuals have knowledge of, have access to, have the ability to afford and are supported in behaviors that will enhance health. Also, these resources determine access to neighborhoods, occupations and social networks that have divergent risk and protective factors. Link and Phelan (2002) explain that "housing that poor people can afford is more likely to be located near noise, pollution, and noxious social conditions; blue-collar occupations tend to be more dangerous than white-collar occupations, and social networks with high-status peers are less likely to expose a person to secondhand smoke" (Link & Phelan, 2002, p. 730).

Krieger (2001) states "four implications for action accordingly flow from a social production of disease/political economy of health perspective" (p. 671). The first implication is that an organized, active approach to changing unfair social and economic policies, within the context of a commitment to social justice, is necessary. The second implication is that without conscious attention to issues of social equity, economic growth and public health interventions stand to exacerbate inequalities in socioeconomic position and public health (Krieger, 2001). Another implication is that as the connection between health and human rights is more widely accepted, the field of social epidemiology will gain more credibility and acceptance. Finally, it is the role of the social epidemiologist to monitor public health activity to ensure that social inequalities in health are addressed (Krieger, 2001).

Limitations of the Framework

The drawback to a social production of disease/political economy of health framework is that it is limited to investigations of populations distributions of known risk and protective factors, and most of those are found at the level of the individual rather than at the level of the group. According to Krieger (2001), it also fails to emphasize "whether-and if so, which-specific public health and policy interventions are needed to curtail social inequalities in health, above and beyond securing adequate living standards and reducing economic inequality" (p. 671).

Ecosocial, Eco-Epidemiology & Social-Ecological Frameworks

Since both social and biological factors are responsible for improved public health, new frameworks that move beyond the risk factor paradigm to integrate the two and reflect the multidimensional and dynamic nature of social epidemiology are developing. Each has its roots in the concept of ecology, which is based on the study of interactions between living organisms and their environments over a period time. Each is represented by a unique mathematical model. These ecological approaches consider the interplay between and among biological/molecular, individual, and societal factors (Fleischer, Weber, Gruber, Arambula, Mascarenhas, Frasure, Wang & Syme, 2006).

The ecosocial theory, first introduced by Krieger (2001) in 1994, is a "visual fractal metaphor of an evolving bush of life intertwined at every scale, micro to macro, with the scaffolding of society that different core social groups daily reinforce or seek to alter" (Krieger, 1994, as cited in Krieger, 2001, p. 672). Eco-epidemiology, first proposed by Susser in 1996 is a theory that evokes images of nesting boxes and refers to systems that interact while each maintains localized structures and relationships (Susser, 1996 as cited in Krieger, 2001). Finally, the social-ecological systems theory, outlined by McMichael in 1999, is reflected by a cube representing the past and present, with axes extending from the individual to the entire population, from proximate to distant and from static to mobile throughout the life course and into the future (McMichael, 1999 as cited in Krieger, 2001).

Five Central Concerns

Krieger (2001) identifies five central concerns to an ecological approach to social epidemiology.

• The first concern is scale, which relates to the quantifiable dimensions of phenomena observed over space and time.

• Level of organization identifies the existing hierarchy extending from individual to population to ecosystem.

• The third concern, dynamic states, refers to the connectedness of specific animate and inanimate factors.

• Mathematical modeling demonstrates how organisms and processes are intertwined.

• Finally, an understanding of unique phenomena in relation to general processes serves to explain the central characteristics and processes relevant to conceptualizing the genesis, longevity, and decline in populations (p. 672).

Social, political, and economic processes are vital to the creation of valid epidemiological profiles. Krieger (2001) adds, "two of the frameworks-'ecosocial' and 'social-ecological systems perspective'-additionally explicitly indicate in their very names that ecological analysis is not intended to be a substitute or metaphor for social analysis" (p. 672).

Ecosocial theory is guided by the study of the driving forces behind current and changing patterns of social inequalities in public health; thus, it connects most closely to the social production of disease framework for its origin, differing only in its attempts to combine both biological and ecological analyses (Krieger, 2001). There are four concepts central to ecosocial theory. The first, embodiment, refers to the ways in which we biologically incorporate the physical and social world in which we live. The pathways of embodiment are society's arrangement of power and wealth and the trajectories of our biological and social development, while the interplay between and among the pathways is studied at multiple levels, in multiple domains and at different points in time and space. Finally, the concept of accountability and agency, through an understanding of embodiment and its pathways, relates to institutions, households, and individuals and to researchers who must accurately define the scope and limitations to their studies (Krieger, 2001).

According to Krieger (2001), "the four ecosocial constructs can systematically be used to propose six discrete-yet entangled-multi-level pathways linking expressions of racial discrimination and their biological embodiment across the life course" (p. 672). Among the six pathways are

• Economic and social deprivation,

• Toxic substances and hazardous conditions,

• Socially inflicted trauma,

• Targeted marketing of commodities,

• Inadequate health care, and

• Resistance to racial oppression (Krieger, 2001).

Therefore, rather than adding biology to traditional sociological study, the ecosocial framework advocates a systematic, integrated approach to the study of social epidemiology that will produce new hypotheses as opposed to simply analyzing factors identified by one discipline (biology) in the terms of another (social) (Krieger, 2001).

Terms & Concepts

Eco-Epidemiology: Eco-Epidemiology, first proposed by Susser in 1996, moves away from the risk factor paradigm toward a recognition of multilevel causation. It advocates for studies of health and disease trajectories over time within a social context and call for investigation of the pathways through which biological and social experiences impact health and the health of populations.

Ecosocial Theory: Ecosocial theory seeks to integrate social and biological concepts with historical and ecological perspectives “to develop new insights into determinants of population distributions of disease and social inequalities in health. The central question for ecosocial theory is: ‘who and what is responsible for population patterns of health, disease, and wellbeing, as manifested in present, past, and changing social inequalities in health?’” (Krieger, 2002, p. 3)

Embodiment: Embodiment refers to how individuals integrate, biologically, the physical and social world, from in utero to death. The premise is that our biology cannot be understood apart from a knowledge of our personal and societal history (Krieger, 2002).

Level of Organization: Levels of organization refer to the hierarchical scaffolding of systems from smallest to greatest; for example, from the molecular level of an organism to the entire species.

Mathematical Modeling: A mathematical model is a visual representation of the critical elements of system that is used to explain the system in a more concrete manner.

Medical Sociology: Medical sociology is a subfield of sociology concerned with the relationships between social indicators and health. Medical sociologists are concerned with issues such as the social implications of physical and mental illness, the relationships between physicians and patients, the organization and structure of health care systems and the socioeconomic basis of the health care system.

Population Health: Population health focuses on the improvement in overall health of a population of people by reducing health inequalities among groups. This is accomplished through addressing a broad range of social determinants that impact health of a population. Within this framework, modern medicine and health care systems are seen to have little impact on the overall health of a population.

Psychosocial Epidemiology: Psychosocial epidemiology incorporates both behavioral and biological responses to stress to inform explanations of public health. It is a stress/adaptation theory whose central hypothesis states "chronic and acute social stressors: (a) alter host susceptibility or become directly pathogenic by affecting neuroendocrine function, and/or (b) induce health damaging behaviors" (Krieger, 2002, p. 5)

Public Health: Public health refers to efforts organized by a society, or groups within a society, to promote, protect, and/or restore its people's health. While the medical practitioner's treat individual patients, public health workers seek to treat entire populations.

Social Epidemiology: Social epidemiology involves the study how social, political, environmental, and institutional factors influence the overall health of individuals and populations.

Social Production of Disease/Political Economy Theory: Social production of disease/political economy of health frameworks address economic and political determinants of health within and among societies and the ways in which institutions create and perpetuate inequalities in health. These frameworks do not incorporate biological explanations in their study, which is their chief difference from the ecological perspectives.

Sociological Ecological Systems Theory: Susser first introduced the Sociological Ecological Systems framework in 1996; it incorporates evolutionary biology and historical experience to study how the natural and social environments affect patterns of health, disease, and survival in populations with the goal of making sustainable changes for the future. Of particular interest are the ways in which behavioral adaptations had social as well as physiological impacts on our species. For example, the learning to control fire not only impacted diet, it also improved nocturnal security and, thereby, prolonged group interaction, which, in turn, would have facilitated the emergence of language. One area of study is how climate change is impacting and will continue to impact health.

Bibliography

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Burris, S. (2002). Introduction: Merging law, human rights, and social epidemiology. Journal of Law, Medicine & Ethics, 30 , 498. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=8973964&site=ehost-live

Burris, S., Kawachi, I., & Sarat, A. (2002). Integrating Law and Social Epidemiology. Journal Of Law, Medicine & Ethics, 30, 510–521. Retrieved October 29, 2013, from EBSCO Online Database SocIndex with Full Text. http://search.ebscohost.com/login.aspx?direct=true&db=rst&AN=8973965

Fleischer, N., Weber, A., Gruber, S., Arambula, K., Mascarenhas, M., Frasure, J., et al. (2006). Pathways to health: a framework for health-focused research and practice. Emerging Themes in Epidemiology, 3 , 1-8. Retrieved August 12, 2008 from EBSCO Online Database Academic Search Complete: http://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=28742601&site=ehost-live

House, J. (2002). Understanding social factors and inequalities in health: 20th Century progress and 21st century prospects. Journal of Health & Social Behavior, 43 , 125-142. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=7208893&site=ehost-live

Kindig, D., & Stoddart, G. (2003). What is population health? American Journal of Public Health, 93 , 380-383. Retrieved August 12, 2008 from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=9248163&site=ehost-live

Krieger, N. (2002). A glossary for social epidemiology, part I. Epidemiological Bulletin, 23 . Retrieved August 12, 2008 from Pan American Health Organization http://www.paho.org/english/sha/be_v23n1-glossary.htm

Krieger, N. (2002). A glossary for social epidemiology, part II. Epidemiological Bulletin, 23 . Retrieved August 12, 2008 from Pan American Health Organization http://www.paho.org/english/sha/be_v23n2-glossary.htm

Krieger, N. (2001). Theories for social epidemiology in the 21st century: an ecosocial perspective. International Journal of Epidemiology, 30 , 668-677. Retrieved August 13, 2008 from website http://ije.oxfordjournals.org/cgi/content/extract/30/4/668

Link, B. G. & Phelan, J. C. (2002). McKeown and the idea that social conditions are fundamental causes of disease. American Journal of Public Health, 92 , 730-732. Retrieved August 12, 2008 from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=6627094&site=ehost-live

McMichael, A. J. (2006). Population health as the 'bottom line' of sustainability: a contemporary challenge for public health researchers. The European Journal of Public Health, 16 , 579-581. Retrieved August 14, 2008 from website: http://eurpub.oxfordjournals.org/cgi/content/full/16/6/579

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Suggested Reading

Acevedo-Garcia, D., Sanchez-Vaznaugh, E. V., Viruell-Fuentes, E. A., & Almeida, J. (2012). Integrating social epidemiology into immigrant health research: A cross-national framework. Social Science & Medicine, 75, 2060-2068. Retrieved October 29, 2013, from EBSCO Online Database SocIndex with Full Text. http://search.ebscohost.com/login.aspx?direct=true&db=sih&AN=83457495

Blane, D. (2003). The use of quantitative medical sociology. Sociology of Health & Illness, 25 , 115-130. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=9330506&site=ehost-live

Burris, S., Kawachi, I., & Sarat, A. (2002). Integrating Law and Social Epidemiology. Journal of Law, Medicine & Ethics, 30 , 510. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier. http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=8973965&site=ehost-live

Glymour, B. (2003). On the metaphysics of probabilistic causation: Lessons from social epidemiology. Philosophy of Science, 70 , 1413-1423. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier. http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=12414020&site=ehost-live

Ichiro, K., & Subramanian, S. (2005). Chapter 26: Health demography. In, Handbook of population. (pp. 787-808). Retrieved August 14, 2008, from EBSCO Online Database SocINDEX with Full Text: http://search.ebscohost.com/login.aspx?direct=true&db=sih&AN=21986009&site=ehost-live

Kaplan, G., Siefert, K., Ranjit, N., Raghunathan, T., Young, E., Tran, D., et al. (2005). The health of poor women under welfare reform. American Journal of Public Health, 95 , 1252-1258. Retrieved August 12, 2008 from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=17453737&site=ehost-live

Mitchell, J. A. (2013). Social epidemiology: a tool for examining prostate cancer early-detection decision making among older African American men. Social Work In Public Health, 28, 652-659. Retrieved October 29, 2013, from EBSCO Online Database SocIndex with Full Text. http://search.ebscohost.com/login.aspx?direct=true&db=sih&AN=90465221

Syme, S. (2005). Historical perspective: The social determinants of disease - some roots of the movement. Epidemiologic Perspectives & Innovations, 2 , 1-7. Retrieved August 14, 2008 from EBSCO Online Database Academic Search Complete: http://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=28742750&site=ehost-live

Szreter, S. (2003). The population health approach in historical perspective. American Journal of Public Health, 93 , 421-431. Retrieved August 12, 2008, from EBSCO Online Database Academic Search Premier: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=9248245&site=ehost-live

Yen, I. (2005). Historical perspective: S. Leonard Syme's influence on the development of social epidemiology and where we go from there. Epidemiologic Perspectives & Innovations, 2 , 1-5. Retrieved August 14, 2008 from EBSCO Online Database Academic Search Complete: http://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=28742751&site=ehost-live