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2 The Aging Population and the Psychosocial Implications of Aging DEMOGRAPHIC CONSIDERATIONS OF AN AGING POPULATION Aging has been described in physiologic, psychalogic, behav- ioral, and sociologic terms. A demographic approach, however, leads to defining aging in chronologic terms. Demographically, it is important to distinguish between the aging of individuals and the aging of populations. Interest in the aging of individuals focuses on survival and longevity, which make aging a function solely of changes in death rates. In contrast, the aging of a population refers to whether a population as a whole is getting older or younger and is a function of changes in rates of mortality, migration, and birth. Population aging in this sense is measured ~ terms of such units as median or mean age, proportion of persons 65 years old and over, ratio of persons 65 years old and over to persons under 15, or some other summary unit of the age structure of the whole population. These various measures of population aging might indicate different patterns or different directions of aging in a given popu- lation during a particular period. For example, the proportion of elderly persons (65 and older) and the proportion of children (un- der 151 could both be increasing. The aging of individuals and the 15

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16 AGING IN TODAY'S ENVIRONMENT environmental circumstances that influence survival and longevity are of prominent concern in this report. The older population is not a homogeneous group, and its characteristics tend to vary markedly with age. Therefore, it ~ sometimes useful to consider component age groups in analyses of the older population. One common set of groups is 55-64 years, 65- 74 years, 75-84 years, and 85 years and older (U.S. Bureau of the Census, 1984~. In some reports, or for other purposes, different ages or age bands might have special significance; for example, 62 is the age of eligibility for Social Security benefits. Although a population's entire age range could be included in a review of demographic aspects, the older groups- specifically those over 55, 65, 75, and 85 are usually of more concern because the effects of aging on their health, social, and economic characteristics are more pronounced. The aging of the U.S. population in the twentieth century is vividly described by a comparison of the age structure of the population in 1950 and 1980. In 1950, 8% of the population (12 million) were 65 or older, and in 1980, almost 12%0 (28 million) were 65 or older (Brady, 1985~. The increased survival or aging of individuals in a population is measured principally, however, by an increase in average expectancy of life at birth, reductions in mortality rates, increases in proportions of the population that ~ ~ e e survive to various ages, or increases m average years o; : remammg life. . Life expectancy is the average number of years a person is expected to live (either from birth or from any given age); as calculated from current age-specific mortality rates, assuming that these rates will remain unchanged for the lifetime of the person. Life expectancy at birth is a summary indicator of progress in the reduction of mortalityspecifically, premature mortality and Is most sensitive to reductions in infant and child mortality. This measure indicates an increase of 24.2 years in life expectancy at birth for the U.S. population during the first 80 years of this centuryfrom 49.2 years in 190~1902 to 73.6 years in 1980. From 1930 to 1980, the increase in life expectancy was more pronounced for persons under age 65 (+ 8.2 years) than persons 65 or over (+ 4.1 years), and much of the increase occurred between 1930 and 1954 (U.S. Bureau of the Census, 1984~. Recent U.S. data indicate that life expectancy increased more between 1970 and 1983 than between 1950 and 1970 (Figure 2-1~. These recent

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AGING AND PSYCHOSOCIAL REPLICATIONS 80 75 Oh CE: ~ 70 Z 1 .~--~ -a Z 65 in: LO X 60 LU - 55 17 '~ White Female - ,/ .. All Other Female ol I I 1950 1955 1960 All Other Male . - 1965 1970 1975 ~ 980 1985 YEAR Black Female White Male Black Male FIGURE 2-1 Life expectancy at birth by race and sex, United States, 1950-1983. Source: National Center for Health Statistics (1986a). . increases resulted primarily from decreases in mortality among those 45-64 ~d 65-84 years old (Figures 2-2 and 2-3~. Life span* is the greatest age attainable by a member of a species or other group in question (Schneider and Reed, 1985~. For humans, the documented life span is about 10~110 years. Gains in extending life expectancy at birth have been impressive during the past 80 years, but life span appears to have changed little, if any. Claims of unusually long-lived persons or populations, when carefully investigated, have not been substantiated (Leaf, 1982~. If the optimal life expectancy is achieved and, as suggested by Hayflick (1974), all persons live healthy and active lives until they *Throughout this report, life span refers to maximal life span, unless otherwise specified.

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18 1 0,000 8,OOO 6,000 4,000 o ~ 2,000 o o to 0 A: G 1,000 800 600 400 200 100 80 60 40 2t) 10 ~ I 1 1 AGING IN TODAY'S ENVIRONMENT 40,000 MALE 85 Edward and Over 1 1 1950 1955 1960 1965 1970 1975 1980 1985 YEAR 40,000 20,000 1 0,000 8,000 6,000 4,000 2,000 1,000 800 600 400 200 100 80 60 40 20 10 1950 1955 1960 1965 1970 1975 1980 1985 YEAR FIGURE 2-2 Death rates by age and sex, United States, 1950-1984. Source: National Center for Health Statistics (1986c). reach 100 and then die peacefully in their steep, a life-table curve of survivorship would be rectangular, rather than triangular (linear decelerating curve). The demographic life-table curves for popu- lations from 1890 to 1978 have become increasingly rectangular, and opinions vary as to whether this pattern is likely to become more pronounced (Fries, 1980; Schneider and Brody, 1983; Siegel and Taeuber, 1986; U.S. Bureau of the Census, 1984~. Figure 2-4 shows the shift in the curve for survival of white females according to current life tables for the United States. Although life expectancy at birth has not yet reached 100 years, it has been rising almost steadily in the United States dur- ing this century. A logical extension of the present trend might be depicted by either a theoretical nearly rectangular curve (assum- ing a 90 angle and a steep fall just before or at the age suggested for the specified maximal life span) or a horizontal curve contin- uing through age 85 followed by a less steep fall (Schneider and

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AGING AND PSYCHOSOCL`4L IMPLICATIONS 100 90 Oh lo: ~ 80 At Age 75 At Age 65 an ~ 70 CL ~,~ 60 - ~0 o 1 900- 1 902 1919- 1921 19 At Age 40 Ate I I I i I I I , I 1939- 1949- 1959- 1969- 1976 1982 1941 1951 1961 1971 YEAR FIGURE 2-3 Average expectation of life at specified ages in selected years, 1900-1982. Source: National Center for Health Statistics (1978b, 1985b). Brody, 1983) (Figure 2-4). It is, of course, possible that scientific discoveries could alter ideas about maximal life span. The repre- sentation of the 2050 cohort in Figure 2-4 implies the existence of a fixed maxanal life span for humans. To achieve the Squaring of the life-table curve relight require several more decades, during which additional ways of extending human life might be developed and applied. The latter prediction, a flattening of the mortality curare, is reported to be more consistent with the observed mor- tality data for persons 50 and over (Manton, 1980), although it is controversial. At the crux of the clebate Is the nonutility of cross-sectional mortality data, as used in a demographic life table, for examining the question of an increase in life span that results from envi- ronmental changes of the twentieth century changes that have had a remarkable impact on mortality rates and life expectancy. True longitudinal mortality (cohort-survival) data, analogous to

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20 80 70 ~ 60 At C: 50 40 30 20 10 o AGING IN TODAY'S ENVIRONMENT 10o 1890 \ (Massachusetts) ~ \\ \- 2050 (Middle Series) ' 1gOO-1902 \ \\\\\\ (Original Death Registration Series) :~ \ \ \ \ \ \ \ \ \ \~\ \ 1959-1961 1919-1921 (Death Registration from States of 1920) \\\\\\ \\\\\ \ _ 1939-194t 1 1 1 1 1 1 1 1 ~: 0 10 20 30 40 50 60 70 80 90 100 1 10 120 AGE (Years) FIGURE 2-4 Percent of cohort of white females surviving to specific ages, according to current life tables for the United States, 1980-2050. Reprinted with permission from Siegel and Taeuber (1986~. survival data obtained in experimental studies, are needed to ex- amine the question of an increase in life span in human populations (Riley, 1981a). The mortality of people aged 90 and over in 1980 is that of people who were born in 1890 or earlier, who were exposed to an environment vastly different from that of people born in 1980, and who are the survivors of a group that had higher mortality rates at earlier ages. A cohort life table based on the longitudinal age-specific mortality experience of cohorts born in the twentieth century is needed to assess the question of an increase in maximal life span. Although these data are not available on people over 86, among whom 1~20%o of all deaths occur, the data that are available for the United States (Vandenbroucke, 1985) support the observation of a continuous increase in life expectancy at age 85 since the 1700s. Modifications in the longevity differences within sexes and races suggest the importance of environmental (nongenetic) and genetic factors in determining longevity (Figure 2-1~. Life ex- pectancy by sex diverged progressively from 1900 to 1972. Mor- taTity rates for males are now substantially higher than those for

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AGING AND PSYCHOSOCIAL IMPLICATIONS 21 females at every age, and the difference is reflected in the greater life expectation at birth for U.S. females (78 years) than mates (71 years) in 1983. The lessening in the divergence since 1979 (NCHS, lg86b) suggests an environmental influence on longevity. Most of the difference is accounted for by differences in the mortality of men and women at ages over 65 and might be due in part to sex differences In smoking (Feinieib and Luoto, 1984; Miller and Gerstein, 1983; Retherford, 1972; Waldron, 1976~. The divergence of death rates by sex has occurred both among whites and among blacks and people of other races, although it has been slightly greater among blacks and people of other races. At every age and for most causes of death, females have a sur- vival advantage. There is evidence of an intrinsic or constitutional difference in survival, but there is also evidence that the survival advantage is associated with extrinsic factors. Nevertheless, it is still unclear why females live longer than mates. Life expectation at birth for U.S. whites in 1984 (75.3 years) was substantially greater than that for blacks and people of other races combined (69.7 years). Most of this difference is attributable to the lower mortality of whites younger than 65 (Figure 2-1~. In recent years, the difference in mortality between the two major U.S. racial groups (whites and blacks) has been rapidly narrowing. Most of the difference in death rates between whites and blacks at ages below 65 might result from differences in socioeconomic status between the racial groups (e.g., in occupation, education, and income) and associated differences in life-styTe and environmental exposures. The death rates of blacks and people of other races exceed those of whites at all ages from 65 to 80; from age 80 on, blacks and people of other races combined seem to have lower mortality rates (Manton et al., 1979; Nam et al., 1978~. The relatively favorable mortality position of blacks and people of other races above the age of 80 the "crossover effects suggests that socioeconomic differences are weaker determinants of mortality at ages above 65 than at ages below. An alternative hypothesis is that the blacks who have survived the excessive environmental stresses of their earlier years might be a selected subpopulation that is genetically endowed with the ability to live an especially long life. Manton (1980) refined this hypothesis by suggesting that the crossover phenomenon might be due to the effect of genetic selection of differential mortality

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22 LU A a: ~ LL U) CL 2 Z _ AGING IN TODAY'S ENVIRONMENT 600 500 400 300 200 100 o 1920 1940 1960 1980 - - ~::'~~ - __~ of_ - - - 75-84 65-74 , _ 55-64 1 1 1 1 1 YEAR 2000 2020 2040 FIGURE 2-5 Percentage increase in older population, by decade, 1900-2050. Source: U.S. Senate Special Committee on Aging (1986~. rates in a heterogeneous population. According to his argument, if people in two populations are heterogeneous with respect to their endowment for longevity, crossover or convergence of the age-specific mortality rates of the two populations can occur if one population experiences markedly higher mortality at earlier ages. In our example then, those who are robust make up a larger proportion of the surviving black population than of the surviving white population as they age. The elderly population of the United States is growing much more rapidly than the population as a whole (Siege} and Taeuber, 1986~. As the total population increased lie In the 1970s, the population 65 and over increased by 28% and the population 85 and over increased by Who. The population aged 85 and over is the fastest-increasing of the four older age groups (55-64, 65-74, 7~84, and 85 and over) and is expected to triple between 1980 and 2020 (Figure 2-5~. Census projections for 2050 indicate that the proportion of the population 65 and over will be almost twice as great as today22% comparer] to 12~7o (Siege! and Taeuber, 1986~. Fries (1980, 1983) has proposed that the period of chronic morbidity in later years will be compressed as human life ex- pectancy approaches the theoretical maximum-of 10~110 years, although the notion has been questioned (Schneider and Brody,

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AGING AND PSYCHOSOCIAL IMPLICATIONS 23 1983). According to Fries (1983), compression of morbidity occurs if the age at which chronic-disease symptoms first appear increases more rapidly than life expectancy. If increasing numbers of people continue to reach advanced ages (85 and over), at which rates of morbidity and concomitant physical limitations are higher, Fries's prediction does not appear likely to be realized. There Is no evi- dence of declining morbidity and disability among the population over 65. The Special Supplement on Aging in the 1985 National Health Interview Study (NCHS, 1986b) found that most people 65 and over who were living in the community were in good health on three measures perceived health status, number of bed days, and activity limitationalthough health generally declined with in- creasing age. One-third of people 65 and over consider themselves to be in excellent or very good health. Slightly more than 60~o of those over 65 experienced no condition or illness that confined them to bed for 1 day or more. The greatest change with increasing age was in limitation of activity; over 60~o of those 65-84 reported no I~rnitation, compared with approximately 40% of those 85 and over. However, because the subjects of the survey were not institutionalized, these data should not be interpreted to mean that the health of the total population aged 65 and over is good, especially the group aged 85 and over; healthy older people are more likely to remain in the community than those in extremely poor health. A large proportion of the population aged 85 and over are in nursing homes (23~o in 1977), and the health of people in nursing homes Is generally poor. A comparison of the proportion of the U.S. civilian noninstitutionalized and nursing-home populations having activity limitation (Tables 2-1 and 2-2) shows a marked difference in the activity limitation of those 65 and over. Compos- ite data on the total population aged 65 and over indicate that about 20~o of elderly persons are disabled to some degree and a lower percentage limit their activity severely (Figure 2-6~. On the basis of comparisons with countries having the lowest overall mortality (Table 2-3), the prospects for future increases in life expectancy in the United States seem modest (U.S. Bureau of the Census, 1984), although a marked increase in the number of person-years for persons over 75 and 85 is expected. Although the decline in death rates at the higher ages is expected to slow, there is no agreement as to whether this trend will result in an increasing

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24 AGING IN TODAY'S ENVIRONMENT TABLE 2-1 Dependence of Civilian Noninstitutionalized Population in Activities of Daily Living, United States, 1979a Population People with Activities Limited Age (l,OOOs) 1,000e Percentage < 18 153,177 4,852 3.2 18-44 86,378 676 0.8 45-54 22,744 526 2.3 55-64 20,713 832 4.0 65-74 14,929 1,043 7.0 75-84 6,869 1,101 16.0 > 85 1,544 674 43.7 aData from National Center for Health Statistics (1983~. Activities of daily living include bathing, dressing, using toilet room, mobility, continence, and eating. TABLE 2-2 Dependence of Nursinga-Home Residents in Activities of Daily Living, United States, 1977 Age Population People with Activities Limited Number Percentage All 1,303,100 1,178,700 90.4 < 65 177,100 135,600 76.6 65-74 211,400 181,900 86.0 75-84 464,700 431,100 92.8 > 85 449,900 43D,100 95.6 aData from National Center for Health Statistics (1981a). Activities of daily living include bathing, dressing, using toilet room, mobility, continence, and eating. rectangularization of the life-table curve (Schneider and Brody, 1983; U.S. Bureau of the Census, 1984~. According to present knowledge, a life expectancy at birth of 81 years for females and 73 years for males and a life expectancy at age 65 of 21 years for females and 16 years for males appear attainable in the United States by the year 2000. These demographic trends are important because older people experience a greater share of morbidity and require a dispropor- tionate quantity of health and social services. The large increases

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AGING AND PSYCHOSOCIAL REPLICATIONS 12 10 my 6 e 4 2 o r FEMALE MALE 6~74 75-84 ~ ~ 25 AGE FIGURE 2-6 Percentage of population with severe activity limitation, 1982. Source: U.S. Senate Special Committee on Aging (1986~. TABLE 2-3 Life Expectancy at Birth for Females and Males in Selected Countries (1980-1984)a Country Life Expectancy at Birth Male Female Japan, 1984 74.8 80.7 Norway, 1983 72.8 79.8 Australia, 1983 72.2 79.0 United States, 1982 70.9 78.4 West Germany, 1984 70.5 77.1 Venezuela, 1980 65.8 71.4 Mauritius, 1982 63.6 71.1 aMost recent data available at time of publication from the World Health Organization (1985~; United Nations (1984~.

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26 AGING IN TODAY'S ENYIRONMENT in the numbers of people in the higher age groups in future decades will have important health, social, and economic implications. PSYCHOSOCIAL ENVIRONMI:NT Having a sense of purpose ~ closely tied to one's health and well-being. A Joint American Medical Association-American Nursing Association Task Force (1983) addressed improvement in the health care of the aged chronically ill and concluded that Pa sense of purpose and control over one's life is integral to the health of the aged. The elderly, especially those in institutions, are often isolated and understimulated. Many older people might also feel, justifi- ably, that they have lost control over their lives and environments. They are more likely to need assistance with tasks they once per- formed independently and to require more extensive medical care and contact with a health-care system, which often encourages obedient, "manageable" behavior (Lorber, 1975; Wills, 1978~. In addition, the psychosocial environment might actually worsen naturally declining health; interpersonal relationships are related to a variety of physical health indexes (Kiecolt-Glaser et al., 1985~. Loneliness, lack of stimulation, and loss of indepen- dence can have negative effects on such factors as immunocom- petence, blood cortiso! and glucose concentrations, and carbohy- drate metabolism. Lack of control over one's life and environment may suppress the immune system (LaudensTager et al., 1983), and this might help explain the age-associated general decline in im- munocompetence. In contrast, improvement in the psychosocial environment through an increase in activity, more social contact, and a higher degree of independencealso improves physiologic factors (Larger and Rodin, 1976; Schulz, 1980~. Studies of nursing-home residents have shown that increases in responsibility and independence affect both pyschologic and physi- cal health. Langer and Rodin (1976) reported the effects of encour- aging elderly convalescent-home residents to make a greater num- ber of choices and to assume more responsibility for daily events. Their subjects became "more alert and active and reported feeling happier, as well as showing significantly greater health improve- ment than the control group. After 18 months, the mortality rate among the "responsible (experimental) subjects fell from 25~o to 15%, but rose to 30~o in the control group. Schulz (1976) showed

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AGING AND PSYCHOSOCIAL IMPLICATIONS 27 that giving elderly people in nursing homes increased responsibility for arranging a student visitation program significantly increased their activity, satisfaction, and health. Langer et al. (1979) also found that increased control over daily events led to improve- ments in memory, satisfaction, and physical health among elderly subjects. All these factors social isolation, understimulation, and lack of control over daily events can be chronic physiologic stressors (Arnetz, 1984; Rodin, 1986~. Even relatively mild stress can re- duce immune response in both the young and the old. Stress reduction, correspondingly, increases immunocompetence. Kiecolt-Glaser et al. (1985) found that geriatric residents of independent-living facilities who learned relaxation techniques had improved immune-cell activity and reduced production of antibod- ies in response to ax introduced Herpes simplex virus (presumably reflecting improved control of virus replication and latency by the cellular immune response). In addition, Rodin (1986) showed that elderly subjects who learned skins for coping with daily stress had reductions in blood cortmo} concentrations, presumably as a func- tion of stress reduction, and they maintained the reductions 18 months after the intervention. A final example is hemoglobin Am, which is an irreversibly glu- cosylated derivation of HbA. This form of hemoglobin is normally present in increased levels in diabetic patients and also appears to increase naturally with age (Arnetz et al., 1982; Graf et al., 1978~. However, social factors can also affect blood glucose, and therefore HbA~C, concentrations (Arnetz' 1984~.