Defining Health and Wellness - Life Expectancy

During the twentieth century, advances in public health and medical care helped Americans to lead longer, healthier lives. Along with infant mortality, life expectancy rates are an important measure of the health of the population. Life expectancy at birth is strongly influenced by infant and child mortality. Life expectancy in adulthood reflects death rates at or beyond specified ages and is independent of the effect of mortality at younger ages.

Figure 1.3 shows the upward trend from 1970 to 2003 in U.S. life expectancy for males and females at birth. The numbers in Table 1.8 reveal that throughout the twentieth century, life expectancy increased dramatically, from 46.3 years in 1900 to 74.3 years in 2000 for males and from 48.3 years in 1900 to 79.7 in 2000 for females. In Health, United States, 2005, the NCHS additionally reports that life expectancy at age sixty-five also increased over the twentieth century. Unlike life expectancy at birth, which rose early in the twentieth century, much of the rise in life expectancy at age TABLE 1.5 Number of infant, neonatal, and postnatal deaths and mortality rates by sex, 2002–03 Donna L. Hoyert, et al., "Table 3. Number of Infant, Neonatal and Postnatal Deaths and Mortality Rates by Sex: United States, 2002–2003," in Deaths: Final Data for 2003, Health E-Stats, Centers for Disease Control and Prevention, National Center for Health Statistics, January 19, 2006, http://www.cdc.gov/nchs/data/hestat/finaldeaths03_tables.pdf (accessed January 24, 2006)sixty-five occurred after 1950 in response to improved access to health care, advances in medicine, healthier current lifestyles, and better health throughout the lifespan.

TABLE 1.5
Number of infant, neonatal, and postnatal deaths and mortality rates by sex, 2002–03
[Rates are infant (under 1 year), neonatal (under 28 days), and postneonatal (28 days-11 months) deaths per 1,000 live births in specified group]
Race and Sex	2003		2002		Percent change from 2002 to 2003
	Number	Rate	Number	Rate
SOURCE: Donna L. Hoyert, et al., "Table 3. Number of Infant, Neonatal and Postnatal Deaths and Mortality Rates by Sex: United States, 2002–2003," in Deaths: Final Data for 2003, Health E-Stats, Centers for Disease Control and Prevention, National Center for Health Statistics, January 19, 2006, http://www.cdc.gov/nchs/data/hestat/finaldeaths03_tables.pdf (accessed January 24, 2006)
Infant
Total	28,025	6.85	28,034	6.97	−1.7
Male	15,902	7.60	15,717	7.64	−0.5
Female	12,123	6.07	12,317	6.27	−3.2
Neonatal
Total	18,893	4.62	18,747	4.66	−0.9
Male	10,636	5.08	10,408	5.06	−0.4
Female	8,257	4.14	8,339	4.25	−2.6
Postneonatal
Total	9,132	2.23	9,287	2.31	−3.5
Male	5,266	2.52	5,309	2.58	−2.3
Female	3,866	1.94	3,978	2.03	−4.4

In 2002 life expectancy at birth for the total population reached a then-record high of 77.3 years, up from 75.4 years in 1990. The CDC estimated that in 2005 life expectancy at birth had increased to 77.6 years. Life expectancy at birth for females in 2002 (79.9 years) outstripped that of males (74.5 years) by 5.4 years. White females in 2002 had the longest life expectancy, 80.3 years, compared with 75.6 years for African-American females, 75.1 years for white males, and 68.8 years for African-American males. (See Table 1.8.)

Many factors contribute to the significantly lower life expectancy for African-American men. In addition to issues of access to health care, some observers suggest that African-American males must deal with greater social, economic, and psychological stress than other men, leaving African-American men more susceptible to various diseases. Among African-American males in 2000–02, the observed number of deaths resulting from homicides, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), and cardiovascular disease was much higher than would be expected based on their proportion in the overall population. (See Table 1.9 for causes of death of African-American males compared with other populations.)

FIGURE 1.2 Infant mortality rates by race and Hispanic origin of mother, 2002–03 "Figure 28. Infant Mortality Rates by Detailed Race and Hispanic Origin of Mother: United States, 2000–2002," in Health, United States, 2005, Centers for Disease Control and Prevention, National Center for Health Statistics, November 2005, http://www.cdc.gov/nchs/data/hus/hus05.pdf (accessed December 8, 2005)

As deaths from infectious diseases declined, mortality from chronic diseases, such as heart disease, cancer, and diabetes, increased. Table 1.9 displays the ten leading causes of death in the United States in 1980 and 2002, and Figure 1.4 shows the rate of overweight and obesity between 1960 and 2002, with a sharp increase beginning in 1976–80. Overweight and obesity are considered contributing factors to at least four of the ten leading causes of death in 2002—diseases of the heart, malignant neoplasms (tumors), cerebrovascular diseases (diseases affecting the supply of blood to the brain), and diabetes mellitus. (Obesity also may be implicated in another leading cause of death—kidney disease or chronic renal failure, which are called nephritis, nephrotic syndrome, and nephrosis in Table 1.9.) Table 1.9 also reveals the rise of diabetes as a cause of death. In 1980 it was the seventh-leading cause of death, claiming nearly thirty-five thousand lives. By 2002 it rose to the sixth-leading cause of death overall, claiming more than seventy-three thousand lives and being mentioned on the death certificates of more than twice as many additional deaths. Epidemiologists and medical researchers believe that the increasing prevalence of diabetes in the U.S. population and the resultant rise in deaths attributable to diabetes are direct consequences of the obesity epidemic in America.

In 2005 S. Jay Olshansky and his colleagues at the University of Illinois suggested that the steady rise in life expectancy the U.S. enjoyed during the past two centuries may soon come to an end. The investigators used obesity prevalence data and previously published estimates of years of life lost from obesity to project life expectancy. Instead of using historical trends to forecast life expectancy, they calculated in reverse, assessing the fall in death rates that would occur if all obese Americans had a normal weight. Their projections revealed that within fifty years obesity is likely to reduce the average life expectancy in the United States by at least two to five years from its 2005 level of 77.6 years. The impact of obesity and its health consequences on life expectancy was considered larger than cancer or heart disease (S. Jay Olshansky et al., "A Potential Decline in Life Expectancy in the United States in the 21st Century," New England Journal of Medicine, vol. 352, no. 11, March 17, 2005).