During the past several decades, advances in medical science have given us sophisticated new devices, drugs, and technology that improve our armamentarium for carrying out the task of healing. The general concept of pathology-driven medical care has always been relatively straight forward for the public and policymakers to understand: medical care is a safety net for citizens who are unfortunate enough to become ill. Pediatricians, however, also have a long history of understanding that optimum child well-being is the product of multiple “determinants of health,” of which medical care is only one, and perhaps not the most important.
This article reviews the concept of how health outcomes are influenced by multiple determinants and also promotes the concept of a “life-course” health policy1 approach — a process where decision-makers consider determinants, determinant effects on childhood health, and the logical link between child and adult health outcomes when setting policy priorities. This approach broadens the concept of health and well-being beyond traditional medical care and allows a population’s health to benefit not only from modern medical practice and new technology but also from the practice of giving “health” a place in all policy considerations (see Sidebar).
Health care providers are positioned to use their understanding of disease prevention and experience with acute care to inform “upstream” policy decisions that influence the health determinants of their patients and communities.
Investments in childhood health will result in healthier future adult populations, yielding greater productivity and less costly remediation.
Greater emphasis should be placed on enhancing maternal and early childhood environments, especially for children during the neonatal to school-age interval, with an emphasis on readying children to learn when they enter K-12 education.
Opportunities to improve health should be included in all policy debates, including budget justifications for policies that influence health determinants beyond direct medical care; for example, education budgets are also health budgets.
Determinants of Health
During the past 20 years, the understanding that population health outcomes are influenced by multiple determinants of health has grown. Based on the work of Evans and Stoddart,2 Kindig, and others recently offered the framework below for considering population health outcomes and investments3 (See Figure 1).
Figure 1. Framework for considering population health outcomes and investments. From: Kindig DA. What is population health? Improving population health. Policy. Practice. Research. Available at: www.improvingpopulationhealth.org/blog/what-is-population-health.html. Accessed Jan. 4, 2011. Source: Kinding DA.
The right side of Figure 1 represents the determinants of population health outcomes, which have been divided into five categories: medical care, individual behavior, social environment, physical environment and genetics. Medical care includes prevention, treatment, and management of disease. Examples of individual behaviors include smoking, exercise, and eating habits. The social environment includes socioeconomic factors, most often measured by income, education, and occupation, while the physical environment consists of air and water quality, as well as the built environment.
Genetics refers to those inherited characteristics that determine health outcomes, most of which have been thought to be unmodifiable. However, the emerging field of epigenetics is indicating that gene expression is influenced by determinant factors, such as environmental exposures or high stress levels, interactions that can become embedded in and change biological systems for better or worse.4,5
Although we list these determinant categories independently, they have substantial and complex interactions with each other over the life course. Figure 1 also shows a small arrow going from outcomes to the determinant categories. This is to remind us that some outcomes also have a “reverse causality” effect on determinants. An example could be that, while we know that social determinants, such as income, have an effect on outcomes, the outcome of being unhealthy can also have a negative effect on income.
The model also serves as a framework for considering disparities in health outcomes, demonstrating how positive or negative determinants may be specific for different groups, resulting in unequal health outcomes. Within disparities, multiple domains exist that could be policy targets, such as race/ethnicity, socioeconomic status, gender, and geographic location.
Of all the determinant categories, the least appreciated as major contributors to health outcomes are the social determinants of health, such as income, education, occupation, and social cohesion. In the past two decades, a new academic field of social epidemiology has developed.6
It is beyond the scope of this article to summarize this body of work. However, one of its major findings has been the social gradient in health, in which it is not only the extremes of high and low levels of education and income which have health outcome effects, but also at most gradations in between. One of the most important investigators in this field is Sir Michael Marmot, a British social epidemiologist. Figure 2, which clearly illustrates this concept, is from one of Marmot’s studies using the British civil-servant Whitehall data.7
Figure 2. Whitehall relative risk of coronary heart disease death in different grades “explained” by risk factors (age standardized). Source: Adapted from Marmot et al. Changing social class distribution of heart disease. BMJ. 1987;(6145):1109–1112.
The four administrative job categories reflect different education and income profiles among British civil servants. It can be seen that there is increased mortality from coronary heart disease (CHD) at each of the four occupational levels (the “social gradient”).
In addition, it can be seen that the contributions to this mortality from common risk factors, such as blood pressure, smoking, and cholesterol, increase with lower occupational grade. The amount of mortality not explained by these risk factors, in a British system where all have access to medical care, is quite remarkable. Much active research is currently investigating the reasons for the unexplained variance, with strong indications that neuroendocrine and immunologic “stress” pathways are involved.
Childhood Development and Determinants
Pediatricians have always been able to see the benefits of what a nurturing early child environment can produce and, unfortunately, the detriment associated with stressful exposures. No longer is there strict debate between “nature vs. nurture” solely causing an outcome but rather a clearer understanding thatboth interact and have profound effects during childhood development.5,8
The outcome of different developmental stages is dependent not only on one’s inherent genetic makeup but also on the quality of the determinant inputs beginning in utero and extending throughout childhood and beyond. These early interactions set the foundation for the ability to learn, interact with society, and ultimately the health and well-being for children and adults.9
The genetic roadmaps that guide in utero and early childhood development are not fixed plans but are templates shaped by interactions with the surrounding environment. We know this to be especially important for brain development where nurturing and stimulating influences provide an opportunity for an optimal neurologic outcome and a readiness to learn. Sensitive periods exist for when the modeling of neuronal circuitry is most optimal. Failing to encounter positive influences during these periods or encountering negative exposures are missed opportunities that can be difficult to remediate later in life.
Children are not only born with their genetic makeup but are also born into an “ontogenetic niche,” a term coined by West and King and further developed by Eisenberg.8 This “niche” refers to children inheriting not only genetic material but their family’s ecological and social setting — parenting skills, housing, neighborhood, schools, etc. — all of which can have a profound effect on how a child’s genetic canvas is shaped and all of which fall within the broad determinants of health.8 Living in a niche that results in chronic stress exposure appears to have effects on health across the life-course.
Exposure to adverse living environments, such as exposure to violence, physical or mental abuse, parental depression, and a general lack of a nurturing environment, can result in biological changes, such as insulin resistance, adverse effects on brain development and memory, increased risk of cardiovascular disease, depression, and suicide.10 High-stress settings also increase the likelihood of adopting detrimental behaviors such as smoking and substance abuse, as well as increasing a person’s risk for obesity and sexually transmitted diseases.4,10
New insights in developmental biology have shown how determinants can influence a child’s outcome across generations. Collins and Lu have described how women exposed to the stress of poverty, poor living and work environments, and racial discrimination across their life course are not only more likely to give birth to low birth weight (LBW) and premature children but also expose the developing fetus to stress reaction hormones leading to changes in fetal genetic expression.11,12
These epigenetic changes are referred to as “fetal programming” and appear to have effects on a child’s health from birth through adulthood. A woman who was exposed to stress-induced fetal programming during her own development may also be predisposed to delivering a premature or LBW child when she becomes a mother, continuing the cycle of ill-health outcomes.13
We also know that starting life as a LBW infant not only often leads to poor childhood health but also is clearly associated with adult chronic diseases, such as cardiovascular disease and type 2 diabetes, illustrating how the origins of many adult diseases occur during childhood, a concept now strongly supported by evidence.14–17
The link between environmental influences and childhood development may explain, to some extent, how disparities in children’s and subsequently adult health can occur. The environment in which a child develops is a reflection of maternal health, the child’s immediate and extended family, their housing and community, all of which are influenced by a family’s social, economic, and health status. This understanding of how early childhood exposures and subsequent development can influence immediate childhood and future adult health, along with the potential to influence health disparities, has led to greater interest in establishing programs and policies to influence the early child environment positively.5,8,18
Interventions and the Value of Education
The timing of when programs/interventions should be initiated is, logically, the earlier the better. Once a sensitive period of development passes, society will be left with trying to remediate the outcome of the missed opportunity with greater investments and less effective measures later in life.19 Heckman has demonstrated that there is a much greater return to society for dollars invested in preschool interventions directed at disadvantaged children than for investments made later in life.19
Economic investigators have echoed this highly favorable cost-benefit outcome for society when investing in early childhood programs,20 although others have pointed out the difficulty in providing this evidence.21 Several programs aimed at fostering positive early parent child rearing skills or augmenting the early learning environment have proven to be successful at improving a child’s cognitive skills, emotional and social development.1,18,19,22 Raising non-cognitive skills, such as motivation and social interactions, may prove to be just as valuable, if not more valuable, than improving cognitive function.
For example, Heckman points out that although IQ scores did not improve for disadvantaged children 3 to 4 years of age who were exposed to the Perry Preschool Program (a high-quality participatory preschool program), the participants were still much more likely to have higher rates of high school graduation, higher incomes, lower rates of welfare assistance, and fewer arrests as adults compared with non-participating controls.19
The level of education is probably as important as medical care and other factors in improving health. A large body of evidence supports this claim, including the fact that people in counties, states, and nations with higher education rates have better health outcomes in many categories.
For example, in 2005, the age-adjusted mortality rate for adults with some education beyond high school was 206 per 100,000. However, it was twice as great for those with only a high school education, and three times as great for those with less than high school education.23 People with more education also have fewer disabilities and better physical functioning. One study estimates that 8 times more lives would be saved by correcting educational disparities than those saved by medical advances in the same period.24
One of the most precise studies, which controlled for many other possible explanations, showed an independent 1% to 3% reduction in mortality rates for each year of additional schooling.25 Education affects many of the determinants of health, influencing future socioeconomic status, place of residence, and risks for unhealthy behaviors, such as smoking, diet, teenage pregnancy, and risk for criminal activity, behaviors that can lead to increased cost to society through lost productivity, medical costs, and remediation programs.26–29
Programs that increase school readiness may be the most attractive interventions at improving long-term population health.26 The achievement gaps that children enter school with tend to persist, affecting their ability to achieve higher standards of living as adults and perpetuating future generations’ exposure to a less-than-optimal health environment.19 The time and opportunity to intervene is in the pre-school years, enabling children to be ready to learn when they enter the formal school system instead of trying to catch up.
Medical care and access to care will always remain important determinants of childhood health and the health of the general population. Embracing a life-course philosophy on setting policy priorities and placing investments upstream instead of trying to remediate poor health outcomes downstream is a policy strategy that is becoming increasingly supported by sound evidence. Early childhood interventions are particularly attractive, especially those that foster school readiness as a place for future health investment.
By acknowledging that health outcomes are affected by more than medical care, we also open ourselves up to including health within all policy decisions: education, housing, the environment, and economic policy debates. Shifting the health-care paradigm to include a broader perspective beyond direct medical care will magnify the advances society makes toward improving the health of children and adults.
- Forrest CB, Riley AW. Childhood origins of adult health: a basis for life-course health policy. Health Aff (Millwood). 2004;23(5):155–164 doi:10.1377/hlthaff.23.5.155 [CrossRef] .
- Evans R, Stoddart GC. Consuming health care, producing health. Soc Sci Med. 1990:33:1347–1363 doi:10.1016/0277-9536(90)90074-3 [CrossRef] .
- Kindig D, Asada Y, Booske B. A population health framework for setting national and state health goals. JAMA. 2008;299(17):2081–2083 doi:10.1001/jama.299.17.2081 [CrossRef] .
- McEwen BS. Protective and damaging effects of stress mediators. N Engl J Med. 1998;338(3):171–179 doi:10.1056/NEJM199801153380307 [CrossRef] .
- Schonkoff JP, Boyce WT, McEwen BS. Neuroscience, molecular biology, and the childhood roots of health disparities: Building a new framework for health promotion and disease prevention. JAMA. 2009;301(21):2252–2259 doi:10.1001/jama.2009.754 [CrossRef] .
- Berkman L, Kawachi I. Social Epidemiology. Oxford University Press; 2000.
- Marmot MG, Adelstein AM, Robinson N, Rose GA. Changing social class distribution of heart disease. BMJ. 1987;(6145):1109–1112.
- Eisenberg L. Experience, brain, and behavior: the importance of a head start. Pediatrics. 1999;103(5 Pt 1):1031–1035 doi:10.1542/peds.103.5.1031 [CrossRef]
- Center on the Developing Child at Harvard University. A science-based framework for early childhood policy: using evidence to improve outcomes in learning, behavior, and health for vulnerable children. Available at www.developingchild.harvard.edu. Accessed June 18, 2010.
- Repetti RL, Taylor SE, Seeman TE. Risky families: family social environments and the mental and physical health of offspring. Psychol Bull. 2002;128(2):330–366 doi:10.1037/0033-2909.128.2.330 [CrossRef] .
- Collins JW, David RJ. Low birth weight and infant mortality. Clin Perinatol. 2009;36(1):63–73 doi:10.1016/j.clp.2008.09.004 [CrossRef] .
- Lu M, Halfon N. Racial and ethnic disparities in birth outcomes: a life-course perspective. Matern Child Health J. 2003;7(1):13–30 doi:10.1023/A:1022537516969 [CrossRef] .
- Emanuel I. Maternal health during childhood and later reproductive performance. Ann N Y Acad. Sci. 1986;477:27–39 doi:10.1111/j.1749-6632.1986.tb40318.x [CrossRef] .
- Barker D, Winter P, Osmond C, et al. Weight in infancy and death from ischemic heart disease. Lancet. 1989;2(8663):577–580 doi:10.1016/S0140-6736(89)90710-1 [CrossRef] .
- Barker DJ. Fetal origins of coronary heart disease. BMJ. 1995;311(6998):171–174 doi:10.1136/bmj.311.6998.171 [CrossRef] .
- Oken E, Gilman MW. Fetal origins of obesity. Obes Res. 2003;11:496–506 doi:10.1038/oby.2003.69 [CrossRef] .
- Rich-Edwards JW, Colditz GA, Stampfer MJ, et al. Birthweight and the risk for type 2 diabetes mellitus in adult women. Ann Intern Med. 1999;130(4 Pt 1):278–284.
- Mercy JA, Saul J. Creating a healthier future through early interventions for children. JAMA. 2009;301(21):2262–2264 doi:10.1001/jama.2009.803 [CrossRef] .
- Heckman JJ. Skill formation and the economics of investing in disadvantaged children. Science. 2006;312(5782):1900–1902 doi:10.1126/science.1128898 [CrossRef] .
- Trefler D. Quality is free: a cost-benefit analysis of early child development initiatives. Paediatr Child Health. 2009;14(10):681–684.
- Frick KD, Ma S. Overcoming challenges for the economic evaluation of investments in children’s health. Acad Pediatr. 2009;9(3):136–137 doi:10.1016/j.acap.2009.02.001 [CrossRef] .
- Hertzman C, Wiens M. Child development and long-term outcomes: a population health perspective and summary of successful interventions. Soc Sci Med. 1996;43(7):1083–1095 doi:10.1016/0277-9536(96)00028-7 [CrossRef] .
- US Department of Health and Human Services. Health United States 2007. CDC/National Center for Health Statistics. March 2008.
- Woolf SH, Johnson RE, et al. Giving everyone the health of the educated: an examination of whether social change would save more lives than medical advances. Am J Public Health. 2007;97(4):679–683 doi:10.2105/AJPH.2005.084848 [CrossRef] .
- Elo I, Preson S. Educational differences in mortality. Soc Sci Med. 1996;42:47–57 doi:10.1016/0277-9536(95)00062-3 [CrossRef] .
- Fiscella K, Kitzman H. Disparities in academic achievement and health: the intersection of child education and health policy. Pediatrics. 2009;123(3):1073–1080 doi:10.1542/peds.2008-0533 [CrossRef] .
- Lantz PM, House JS, Lepkowski JM, Williams DR, Mero RP, Chen J. Socioeconomic factors, health behaviors, and mortality: results from a nationally representative prospective study of US adults. JAMA. 1998;279(21):1703–1708 doi:10.1001/jama.279.21.1703 [CrossRef] .
- Upchurch DM, Lillard LA, Panis CW. Nonmarital childbearing: influences of education, marriage, and fertility. Demography. 2002;39(2):311–329 doi:10.1353/dem.2002.0020 [CrossRef] .
- Lochner L. Education, work and crime: a human capital approach. Int Econ Rev. 2004;45:811–843 doi:10.1111/j.0020-6598.2004.00288.x [CrossRef] .