What determines your health?
Question: What factors determine your health? Your genes? Your level of education? Where you live? How much money you have? How you behave? How easy it is for you to see a good doctor?
Question: What factors determine your health? Your genes? Your level of education? Where you live? How much money you have? How you behave? How easy it is for you to see a good doctor?
Answer: All of the above, and many more.
But how much does each one of these factors individually contribute to your health? This question is important because it can shed light on the types of public health interventions that will yield the highest returns on investment. Although this question is impossible to answer with precision because these factors are inextricably intertwined (e.g., education impacts income, income impacts where you live), a Policy Brief recently published with support from the Robert Wood Johnson Foundation synthesized 30 years of research to estimate different factors "relative contribution" to health.
Here's what the Policy Brief's found:
Environmental factors: about 5%. In a classic article, The Actual Causes of Death in the United States, McGinnis and Foege estimated that 90,000 (4%) of deaths in 1990 were caused by microbial agents (like bacteria) and that 60,000 (3%) were caused by toxic agents (like asbestos). A similar, but more recent, article—Actual Causes of Death in the United States, 2000—estimated 4% for microbial agents and 2.3% for toxic agents. The World Health Organization estimates that 3% of deaths in high income countries are attributable to environmental factors such as air pollution, unsafe water, poor sanitation, and lead exposure.
Medical care: about 10%. Despite the common belief that regular access to quality medical care is the major determinant of health, research overwhelmingly indicates the contrary. A report published by the U.S. Center for Disease Control (CDC) in 1980—before it was renamed Centers for Disease Control and Prevention in 1993—stated that only 10% of deaths occurring in the U.S. in 1977 were attributable to "inadequacies in the health care system." An article published in 2002 also estimated 10%.
Genetics: about 20%. The 1980 CDC report estimated that 20% of deaths were caused by "human biology" (this was before "genetics" became household word). In 2002 an article estimated that 30% of deaths were attributable to genetic predispositions—but emphasized that only 2% were "purely genetic" while the remainder just had some genetic component.
Social factors: about 30%. A report published in 2010 estimated that social factors, such as income and education, accounted for 40% of health outcomes. A study published in 2011, not cited in the Policy Brief, estimated that 10% of all deaths occurring in the U.S. in 2000 were attributable to low education and that 7% were attributable to racial segregation.
Behaviors: about 35%. Seven of the ten studies highlighted in the Policy Brief estimated the extent to which behavior was a determinant of health—estimates ranged from 28% to 50%. Tobacco use was estimated to be responsible for about 19 % of deaths in the U.S., poor diet and physical inactivity 15%, and alcohol consumption 4%.
How we behave influences our health, a lot, but social and economic factors are the key determinants of health because they provide the context in which behaviors take place and shape the choices available to us. A Health in All Policies approach that considers the multiple determinants of health and the pathways through which they impact health is the wisest investment for public health.
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