by different causes at different ages: before age 50, these causes include conditions in infancy, nonintentional injuries, violence, and diseases of the heart and circulatory system at ages 30-50 (Palloni and Yonker, 2012).
3. The health and well-being of young people may help explain health disadvantages that emerge later in life. For example, approximately 80 percent of adults who are regular users of cigarettes or alcohol start these behaviors as adolescents (Kalaydjian et al., 2009; Oh et al., 2010; Viner, 2012). High rates of obesity among children and adolescents can track into adulthood and shed light on patterns of heart disease and diabetes among older people (Tirosh et al., 2011). Exposure to these risk factors, among others, and the pathophysiological damage they inflict generally occurs over many years before the disease processes they induce reach the point of producing clinical symptoms, yet they may play a vital role in understanding disease outcomes later in life.
4. The causal pathways that link early life health risks with subsequent diseases may involve many aspects of development that are seemingly unrelated. For example, health challenges in early life can disrupt intellectual and emotional development, impede physical growth, and limit education and employment opportunities (Fletcher and Richards, 2012), which in turn may set up a lifetime of socioeconomic disadvantage (see Chapter 6). Conditions of austerity may restrict access to health care (see Chapter 4) and limit opportunities to pursue healthy behaviors (see Chapter 5) or live in neighborhoods that promote good health (see Chapter 7).
This chapter compares, for each age group, a set of health indicators in the United States with those in a comparable group of other high-income or “peer” countries. The chapter focuses on illnesses and injuries, not unhealthy behaviors or other modifiable risk factors (health behaviors such as smoking and unhealthy diets are examined in Chapter 5). Unlike the previous chapter, which examined a relatively precise outcome, death, this chapter investigates a more general one, health. Health is more challenging to measure and quantify because it is multidimensional, and it reflects the culmination of a complex set of factors that include exposure to risk (or protective) factors and susceptibility (or resistance) to illness and injury. It is especially difficult to assess cross-national differences in health because of inconsistent data and metrics, conflicting findings, and in many cases, the absence of comparable data. This chapter critically examines the data that are currently available, and Chapter 9 outlines research priorities that will produce a stronger empirical basis for future work on this topic.