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OCR for page 15
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
OCR for page 16
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 mortality—specifically, 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
century—from 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
OCR for page 17
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.
OCR for page 18
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
OCR for page 19
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
OCR for page 20
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
OCR for page 21
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
OCR for page 22
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 today—22% 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,
OCR for page 23
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 limitation—although 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
OCR for page 24
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
OCR for page 25
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~.
OCR for page 26
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 independence—also 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
OCR for page 27
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~.
Representative terms from entire chapter:
life span
