Epidemiologists are concerned with uncovering the factors in populations that determine who gets sick, who stays healthy, who lives, and who dies. Human life is inherently social, and looking toward our societies and geography can help explain who is healthy or sick, and why. “Location, location, location” is a mantra that rings true with respect to life expectancy. In Canada and the United States, men can expect to live to 79 or 76 years, respectively, while women can expect to live to over 80 years. The story is similar for most wealthy and developed countries. By contrast, take Afghanistan or any of several sub-Saharan African countries, where a baby born today could expect to live until his or her mid-40s or 50s.
Temporarily setting aside biologic limitations on health (a loaded issue for another blog post), human-made health limitations clearly exist in our world. A person’s life chances greatly depend on where he or she is born and some people do not reach the same level of health achievable by others. Inequities in life expectancy exist within countries as well: Canada-wide, women residing in the poorest neighbourhoods live two years less on average than women residing in the richest neighbourhoods, and this difference is four years for men. This striking inequity brings us back to the original question: What determines health?
Assuming that human biology is roughly equal between rich and poor places, whether they are neighbourhood or country, we must turn to social factors to answer this question. How human society affects health is the focus of social epidemiologists, who grapple with this exceedingly complex issue every day. Two of these scholars, Dennis Raphael and Juha Mikkonen, have compiled a Canadian-specific list of the determinants of health that have social origins (the “social determinants of health”): Aboriginal status, gender, race, disability, housing, early life, education, income and income distribution, employment and working conditions, unemployment and job security, food insecurity, health services, social safety nets, and social exclusion. A comprehensive and straight-forward review of these factors in Canada can be found in their publication, “The Social Determinants of Health: The Canadian Facts“.
And the fact is that income inequality in Canada is rising. Canada is one of the two OECD countries that saw increases in income inequality over the past two decades. The Canadian middle class is “hollowing-out”, with more people being on the richest and poorest ends of the scale. Knock down the “Occupy” movement all you like, their point still remains a valid concern for health and social well-being that we have not even begun to solve. Raphael and Mikkonen’s social determinants of health are all influenced at the structural level by governmental policy and society. Our solutions to health problems, however, are mostly relegated to the health sector, which can only attempt to bandage the wound. Any real solution to inequities in health and life expectancy must come from sectors outside of health that can address the structural “root causes” of health inequities.
What role do epidemiologists have to play? Understanding the social determinants of health will allow us to frame our work within the societal landscapes of the places in which we conduct our research. This understanding will allow us to indirectly address health inequities by ensuring that our research, from recruitment and data collection to knowledge translation, is undertaken with inequity in mind, and to answer big research questions such as, “how do our ever-changing social landscapes and governmental policies affect health and health inequities in society?”. A role does exist for scientist-as-advocate, because the overall objective of all epidemiologists (and health scientists for that matter) is to improve health and reduce disease in populations. A critical understanding of our society’s role in the unequal distribution of health and disease is only our first step.
Correction Feb. 22, 2013 – Juha Mikkonen’s name was incorrectly spelled as “Jukka” in the original posting of this article. Apologies, Juha.