Tài liệu tâm lý học sức khỏe: Hành vi sức khỏe và tuổi tác

28
Health, Behavior, and Aging
Ilene C. Siegler
Lori A. Bastian
Hayden B. Bosworth
Duke University
Health psychology has always been sensitive to age as an important construct because the
distributions of diseases by age are not random and are important in determining the
psychological impact of different diseases. Epidemiology, on the other hand, studies age as a
prominent risk factor for disease. Both are important in understanding the set of associations
in health, behavior, and aging.
The psychology of adult development and aging looks at persons aging normally, some with
and some without specific diseases, to examine the ways disease influences the aging process.
Health psychology studies individuals with specific physical illnesses and seeks to understand
how the aging process might modify the impact of that disease (Siegler & Vitaliano, 1998). The
psychology of adult development and aging and health psychology are two subdisciplines of
psychology that have multidisciplinary partners. The multidisciplinary aspects of studying
aging are part of gerontology and limited to studying primarily the elderly, whereas the
medical aspects of aging are studied as a postgraduate branch of medicine called geriatrics
(Hazzard, Bierman, Blass, Ettinger, & Halter, 1994; Maddox et al., 1995). Behavioral medicine
is a multidisciplinary approach to understanding problems in health psychology that interact
with the same problems in psychosomatic medicine (Blechman & Brownell, 1998; Matthews, in
press).
Handbooks are common in the psychology of adult development and aging. In each of the
Handbooks there has been a “health psychology” chapter (Deeg, Kardaun, & Fozard, 1996;
Eisdorfer & Wilkie, 1977; M. F. Elias, J. W. Elias, & P. K. Elias, 1990; Siegler & Costa, 1985). As a
group, they provide excellent reviews of the relevant literature that need not be repeated here.
As part of a set of master lectures on adult development and aging, Siegler (1989) was given
the “health psychology” assignment and tried to conceptualize the intersection of health,
behavior, and aging as developmental health psychology. This chapter reflects an updating of
that initial effort and focuses on emergent findings in the past 10 years and aims to be

illustrative rather than exhaustive.
Understanding the issues in health, behavior, and aging first requires discussing what has been
a central question in the field: What is normal aging? Second, some important methodological
ideas are reviewed from the psychology of adult development that will be useful in health
psychology. The chapter then takes up the issue of a life-span developmental versus “phase”
theory view of a developmental health psychology. It then considers some new data and
thinking about women's and men's health in middle and later life, and reviews the findings
from some recent empirical studies that show the excellent results from the synergy of
developmental and health psychology.

WHAT IS NORMAL AGING AND HOW IS IT
DIFFERENT FROM DISEASE?
This question drove the initial longitudinal studies of normal aging, such as the Duke
Longitudinal Study (Busse et al., 1985). Shock's (see Shock et al., 1984) initial observations
were essentially correct, that some, albeit rare, individuals
-469-


age without the typical declines (as was shown by a careful testing of
participants in the Baltimore Longitudinal Study of Aging, BLSA) and normal
aging itself is a relatively benign set of processes (Williams, 1994). This is
not to say that older persons do not have health problems or that the
probability of health problems does not increase with age. But rather, when
they do, they can be attributed to a particular disease process rather than
just the passage of time. The resulting problems then could be considered
the fault of a chronic disease process that is not rapidly fatal, but treated,
and remains as a companion for the rest of life. Thus, it seems “unfair” to
blame aging. It used to be that normal aging was accepted and disease
treated. However, current cohorts raised on such slogans as “Better living
through chemistry” are trying to treat normal aging as well.

A table taken from a recent NIA publication summarizes what the Baltimore
Longitudinal Study of Aging (BLSA) teaches about normal aging (NIA, 1996).
Definitions of normal aging are a moving target and change as a function of
individual's risk modification behavior and effective treatments. Thus, Table
28.1 is true today; but future research may point out changes for future
cohorts. As new cohorts age, they may well be different from current middleaged and elderly persons. As is discussed later, psychology of aging has
spent considerable time understanding these shifting patterns of aging.

METHODOLOGICAL CONCERNS
FROM
PSYCHOLOGY OF AGING
Psychology of aging has made major contributions in the explication of the
meanings of age, period, and cohort and important factors in understanding
development (Baltes, 1968; Schaie, 1965; Schaie & Herzog, 1985). Here, the
focus is on the implications of developmental designs for health psychology.

Period/Time Effects
The definition of a period, or time effect, is a societal or cultural change that
may occur between two measurements that present plausible alternative
rival explanations for the outcome of a study (Baltes, Reese, & Nesselroade,
1988; Schaie, 1977). In order to specifically describe a period, or time effect,
in health and disease, these effects are described in terms of new diagnostic
tools or medical therapies that present plausible alternative rival
explanations for the outcome of a study.
The introduction of the prostate-specific antigen (PSA) test in 1987 is an
example of the effects of period/time effects accounting for age-related
changes in detecting prostate cancer. With the increased use of the PSA test
as a diagnostic tool for prostate cancer, there is now an increasing number
of prostate cancers being diagnosed among older adults that would not have
been diagnosed based on previous diagnostic techniques (Amling et al.,

1998). Because prostate cancer prevalence rates increase with age,
researchers studying longitudinally the relation between age and onset of
prostate cancer would have to account for the introduction of this relatively
new diagnostic tool.


Information is becoming made available quicker and improvements in
diagnostic techniques and treatments are increasing in frequency. This is a
benefit for the population, but it makes research more difficult, particularly if
an intervention is in process and new information or changes in medical
procedure is being made. and available to the public at-large. Subsequently,
health psychologists are going to have to become more aware and flexible in
the way they deal with these increasing period/time effects. An example of
researchers adapting to historical or period effects has been the ongoing
Women's Health Initiative study, in which information on estrogen use is
being collected (Matthews et al., 1997). Since the design of this large
observational and intervention study in the late 1980s (Roussow et al.,
1995), there has been an increased number of data to suggest that the
influence of estrogen
-470is related to long-term benefits, such as preventing or delaying osteoporosis,
heart disease, and Alzheimer's disease (Jacobs & Hillard, 1996). More
recently, researchers have identified newer selective estrogen receptor
modulators (i.e., Raloxifene and lower doses of conjugated estrogen (0.3
mg) that may be as effective as the more traditiona10–625 mg Premarin but
with fewer side effects (Delmas et al., 1997; Bastian, Couchman, Nanda, &
Siegler, 1998; Genant et al., 1997). The increase in awareness of the
possible association of estrogen and diseases, such as Alzheimer's disease,
and the addition of newer therapies may have altered women's perception
and experiences with hormonal replacement medication and influence study
observations.

Human immunodeficiency virus/acquired immunodeficiency syndrome
(HIV/AIDS) information is being made readily available, which is quickly
influencing treatment outcomes. AIDS and aging were once mutually
exclusive conditions: The AIDS epidemic began in young adults and they
died before they had time to age (Justice & Whalen, 1996). Much has
happened since 1982, when the first Centers for Disease Control (CDC)
definition of AIDS was published. Better therapies, specifically protease
inhibitors, have changed HIV infection to be a chronic condition (Flexner,
1998; Hogg et al., 1998). Given the current success of these therapies, more
HIV infected persons should be expected across the life span. It will be
necessary to learn how to adjust management for specific populations, such
as the elderly. More may be learned about the immune function and aging
while treating HIV infection and AIDS in various age groups.
As researchers move from studying diseases cross- sectionally and move
toward examining the disease path and as they continue to apply this
acquired information to interventions, they will need to better understand
period and time effects and the ways they may influence ongoing studies.

Is the Age at Disease Onset
Important?
An area often neglected in the study of aging and disease is whether the
development of a particular disease in young adults has the same etiology
or recommendations for treatment, as among older adults. For example, a
disease that is influenced by age of onset is prostate cancer. The risk of


prostate cancer increases faster with age than any other form of cancer
(National Cancer Institute, 1991). After age 50, both mortality and incidence
rates from prostate cancer increase almost exponentially. Ninety-five percent
of cases of prostate cancer are diagnosed in men between age 45 and age

89, with a median age at diagnosis of age 72 (Winkelstein & Ernster, 1979).
There is widespread clinical impression among physicians treating prostate
cancer that the disease is more virulent and rapidly progressive in younger
men (Meikle & Smith, 1990) and as a result treatment options vary based on
the age of onset. More invasive procedures are used for later stages at
earlier age of onset than at comparable stages at later age of onset.
Depression is another example in which age of onset is an important factor
in understanding the etiology and subsequent treatment. Depression in the
elderly is a serious medical condition that is underdiagnosed and
undertreated (NIH, 1992). A common approach to characterizing depression
has been to study its risk factors and presentations according to age of first
onset. This method dichotomizes depression into early-onset depression and
late-onset depression, generally using the range from age 50 to 60 as a cutoff point (Steffens, Hays, George, Krishnan, & Blazer, 1996). Late-onset
depression is more frequently associated with structural brain changes and
cerebrovascular disease, and early-onset depression seems to be more
influenced by family and genetic factors (Coffey, Figiel, Djang, & Weiner,
1990; Figiel et al., 1991). Clinically, patients with late-onset depression show
more loss of interest, less pathological guilt, more psychosis, and more
generalized anxiety (Krishnan, Hays, Tupler, George, & Blazer, 1995). There
is also evidence that late-onset depressives may be more refractory to
antidepressant treatment than patients with early-onset depression (Hi&e,
Scott, Wilhelm, & Brodaty, 1997) and suffer higher mortality rates (Philbert,
Richards, Lynch, & Winokur, 1997).
Age of Disease Onset by Gender Interaction. Not only is age of disease onset
an important issue to consider when examining the relation between aging,
disease, and behavior, but the consideration of how gender interacts with
age of disease onset is just as important. This is particularly the case for
coronary heart disease because clinical manifestations of coronary heart
disease (CHD) occurs among women on average 10 years later than for
men, with the occurrence of myocardial infarction being almost 20 years

later (Wenger, 1995).
An example of the importance of considering gender in terms of age of onset
interaction is provided in the Framingham study, which is a 30. year followup examining a number of specific risk factors for CHD by age group and
gender. Results from the study indicate that the majority of significant
associations between risk factors and CHD apparent in younger men and
women remain significant in older age groups, but not consistently in both
sexes. Systolic blood pressure and vital capacity, for example, both
demonstrate strong risk associations for CHD in younger men and women
and the association increases for older men, but decreases for older women
(age 65–94). The effects of diastolic blood pressure are strong risk
associations for CHD in younger adults and the effects decrease in older
adults, particularly among older women. The risk association for serum
cholesterol, cigarettes, relative weight decreases the risk of CHD in older
adults, whereas blood glucose increases the risk of CHD (Harris, Cook,
Kannel, & Goldman, 1988).
Another gender interaction is diabetes. At all ages, but especially in
premenopausal women, diabetes mellitus is a far more powerful risk factor
of CHD for women than for men (Barrett-Connor, Cohn, Wingard, &


Edelstein, 1991). Adult onset diabetes, in the Nurses' Health Study was
associated with a three- to sevenfold increased risk of a cardiovascular
event, with this risk amplified by associated risk factors (Manson et al., 199
I). The mechanisms imparting risk among diabetic women are uncertain, but
may include lipid abnormalities, hypertension, fibrinogen abnormalities, and
the upper body obesity syndrome, all of which are common
-471concomitants of diabetes mellitus. Further, after age 45, women are twice as
likely as men to develop diabetes (Wenger, 1995).

Usefulness of a Life Span

Perspective
In the psychology of adult development and aging, it is almost a matter of
catechism that development needs to be understood in a life span
perspective. Is this true in developmental health psychology as well? Two
areas of research that have gotten attention in the past 10 years are the
tremendous increase in the numbers of centenarians and the role of
hormone replacement therapy (HRT) as an antidote to aging for women.
Both research areas argue for lifespan development within particular phases,
not as a continuous process.
Centenarians and the role of health and aging. Centenarian status is not
easy to predict from earlier in the life cycle. It sounds trite to say that one
must live until 80 or 90 to get to be 100; but it is not at all obvious from a
group of very old people, who will be the rare person to get all the way to
100. This not only makes them very hard to locate and to study, but also to
describe. In studies that require cognitive testing, centenarians are generally
seen as expert survivors (Poon, Johnson, & Martin, 1997). When the full
population of living centenarians is studied, the variances are extreme in
both physical health and cognitive functioning (Forette, 1997).

HRT and the Logic of Estrogen-Related
Disease
Until recently, women's health research has mainly focused on reproduction
and cancers unique to women. Given that the incidence of chronic diseases
in women increase after menopause (a marker of midlife), it is logical to use
the terminology pre- and postmenopausal to describe adult women's health.
The postmenopausal period extends beyond age 50 and can be divided into
three additional phases based on the incidence of chronic diseases. As
shown in Table 28.2, women's health can be described in four phases: Phase
1-premenopause; Phase 2-postmenopause (age 50–64) with the
development of diseases such as breast cancer; Phase 3-postmenopause

(age 65–79) with the development of diseases such as heart disease; and
Phase 4-postmenopause (age 80 and up) with the long-term development of
diseases such as osteoporosis and Alzheimer's dementia.
The terminology “estrogen-related diseases” can be used to organize and
describe diseases associated with estrogen. Although some of these
diseases, such as osteoporosis, heart disease, endometrial cancer, and
breast cancer are well established to be associated with estrogen in women
(Col et al., 1997; Colditz et al., 1995; Grady et al., 1992; Grady, Gebretsadik,


Kerlikowske, Ernster, & Petitti, 1995; Newcomb & Storer, 1995), other
diseases like Alzheimer's dementia and colon cancer have been reported to
be associated with estrogen but are generally considered more controversial
(Kawas et al., 1997; Nanda, Bastian, Hasselblad, & Simal, 1999; Paganini-Hill
& Henderson, 1996; Potter, 1995). Estrogen-related diseases can be used as
a shorthand to represent the potential HRT may have on the public health of
women. A much better understanding of how estrogen is related to these
and other diseases can be expected because of anticipated results from the
Women's Health Initiative (WHI; Rossouw et al., 1995). Reported to be the
largest study of women's health in the world, WHI researchers have
compiled a battery of psychological measures in addition to the longitudinal
assessment of disease incidence as outcome measures (Matthews et al.,
1997).
Conversely, there is not a clear marker of midlife in men. However, there
may be a role for discussing phases of diseases in men's health as well. Like
estrogens, androgen levels decrease with age and have a broad range of
effects on sexual organs and metabolic processes. Androgen deficiency in
men older than age 65 leads to a decrease in muscle mass, osteoporosis,
decrease in sexual activity, and changes in mood and cognitive function
(Swerdloff & Wang, 1993) leading to speculation that there may be at least

two phases of chronic diseases related to androgen levels in men. Whether
men over age 65 would benefit from androgen replacement therapy is not
known. Any potential benefits from this therapy would need to be weighed
against the possible adverse effects on the prostate and cardiovascular
system.

EMERGENT FINDINGS ON AGING
AND HEALTH/DISEASE
The literature has matured in this area as investigators have started to ask
important questions about how age interacts with other factors to try to look
at the potential mechanisms that relate psychosocial factors to disease
outcomes. Kop (1997) provided an interesting theoretical statement. He
argued that psychosocial factors, such as hostility and socioeconomic status
are important in understanding the risks of heart disease only under age 55.
Whether this turns out to be true requires significantly more empirical
verification. However, it is consistent with findings reported by House et al.
(1992), suggesting from survey data that the number of chronic conditions

-472reported by individuals stratified by SES and age indicated that the average
number of conditions for an older person, age 75+, in the upper social class
was the same as for a middle-aged person (around age 45) in the lower
social class strata.Jennings et al. (1997) studied middle-aged men (age 46–
64) from the Kuopio study to ask empirical questions about the role of age,
disease (hypertension), and medication on cardiovascular reactivity and
found that there are no simple answers. All three of the factors have effects
of reactivity. Thus, the role of age in studies of health psychology needs to
be determined paradigm by paradigm, and disease by disease.Kaplan
(1992) reported on data from the Alameda county study to ask if risk factor
modification undertaken in later life has an impact on mortality-the answer
is a definite yes. When those over age 70 in the Alameda county study were

followed for 17 years, current smoking, physical inactivity, consuming more


than 45 drinks per month, being more than 10% underweight or 30%
overweight, and having a low social network index were associated with
mortality, whereas marital status, race, and SES were not.

The Role of Health-Related
Quality of Life

Clinicians and policymakers are recognizing the importance of measuring
health-related quality of life to inform patient management and policy
decisions, but researchers have been a little slower to examine this
outcome. An understanding of what determines good health outcomes is
highly valued by patients and is necessary in order to maintain function and,
therefore, improve health-related quality of life (Stewart et al., 1989). One
reason why researchers have chosen not to consider health-related quality
of life as an outcome measure is that this concept misleadingly suggests an
abstract philosophical approach, whereas most approaches used in the
medical contexts do not attempt to include more general notions such as life
satisfaction or living standards and instead concentrate on aspects of
personal experience that might be directly related to health (Fitzpatrick et
al., 1992). Nevertheless, despite the proliferation of instruments and the
theoretical literature devoted to the measurement of health-related quality
of life, no unified approach has been devised for its measurement, and little
agreement has been attained on what it means (Bergner, 1989; Gill &
Feinstein, 1994; Spilker, Molinek, Johnson, Simpson, & Tilson,
1990).Although, health-related quality of life has not been clearly defined, it
is important to begin to consider outcomes other than mortality and
morbidity, particularly as life expectancy continues to increase and chronic

diseases are becoming more prevalent. Health-related quality of life is
important for measuring the impact of chronic disease (Patrick & Erickson,
1993). It will be interesting to see if Baby Boomers have the same patterns
as earlier generations. Physiologic and clinical measures provide information
to clinicians, but they often correlate poorly with functional capacity and
well- being (Guyatt, Feeny, & Patrick, 1993). For example, in patients with
chronic heart and lung disease, exercise capacity in the laboratory is only
weakly related to exercise capacity in daily life (Guyatt et al., 1985). Another
example of health-related quality of life instruments improving assessment
is that these instruments have been shown to be better than conventional
rheumatologic measures as predictors of long-term outcomes in rheumatoid
arthritis in terms of both morbidity and mortality (Leigh & Fries, 1991; Wolfe
& Cathey, 1991).There is evidence of great individual variation in functional
status and well-being that is not accounted for by age or disease condition
(Sherbourne, Meredith, &Ware, 1992). The field of health psychology needs
to consider health- related quality of life because a commonly observed
phenomena that two patients with the same clinical criteria often have
dramatically different responses. For example, two patients, with the same
range of motion and even similar ratings of back pain, may have different
role function and emotional well-being. Although some patients may
continue to work without major depression, others may quit their jobs and
have major depression. Thus, health-related quality of life is often a better
index of the impact that health has on functioning than diagnostic or clinical
criteria. It, however, does not have the same etiologic significance as a
verified diagnosis according to standard criteria.

CONCLUSIONS

Aging has taken on a higher profile given the demographic revolution due to
increased longevity (Qualls & Abeles, in press). Interest in aging issues is

often due to a concern with the health, disease, and disability of the elderly
population (Siegler, in press). As the demographic revolution occurs, it is
important to note that the number of adults with diseases will continue to
increase (prevalence), but because of improvements in diagnostic tools and
treatments, will be able to live longer. However, despite the fact that there


will be increasing numbers of people with chronic diseases, the incidence of
certain diseases continues to decline. This demographic revolution, however,
is spread unevenly around the world (Murray & Lopez, 1996).The writing of
this chapter has lead to three conclusions that summarize current thinking
on health, behavior, and aging:
1. Gender and age interact in important ways during adult life and aging.
This is especially true in terms of diseases such as AIDS, coronary artery
disease, and cancers. In the last decade, gender differences in the
etiology and treatment of diseases have been illuminated. These
differences have provided the impetus to create a women's health
medical specialty. Examples have been presented in this chapter of
gender differences and similarities across the adult life span.
Several studies have examined the issue of differences in health care
use between men and women. Landmark studies identified a gender
disparity in the diagnosis and treatment of chest pain and CHD (Tobin et
al., 1987). This study has led to further studies demonstrating sex
differences in the rates of cardiac catheterization and coronary artery
bypass surgery (Ayanian & Epstein, 1991). These studies have
-473changed the way medical students are taught about evaluating chest
pain and have resulted in the reporting of other gender disparities on
such topics as renal transplants (Held, Pauly, Bovbjerg, Newmann, &
Salvatierra, 1988) and HIV/AIDS (Bastian et al., 1993). The recognition
that there is a need to improve the training of clinicians in women's

health, has led to the development of a new interdisciplinary specialty in
women's health (Wallis, 1992). One consequence of the focus on
women's health has been the widening of the definition of health to
include social interactions, domestic issues, mental health, and
reproductive function (Litt, 1997).
2. Life span development is theory, which at the present time, is not
practical given the state of the science. Researchers are able to use
data at one phase of the life cycle to inform them about developments
in adjacent phases and periods approaching 40 years.
3. Survival as a quantity of life measure is different than quality of life
measures. Although there is a growing emphasis to include healthrelated quality of life as an additional outcome measure other than
morbidity and mortality for health-related interventions, and that healthrelated quality of life is a useful discriminator among different
population segments, and is an important predictor of health and health
behaviors, the field still needs to alleviate a number of measurementrelated issues and difficulties. The continued efforts to identify those
content areas and response dimensions that likely will provide the best
discrimination among populations and the greatest sensitivity to change
are essential to enable health psychologists to guide future health policy
and resources.

ACKNOWLEDGMENTS

This work was supported by grants ROl AG12458 from National Institute on
Aging and ROl HL55356 from National Heart Lung and Blood Institute. The
third author was supported in part by the Department of Veterans Affairs,
Veterans Health Administration, HSR&D Service, Program 824 Funds.