The Factors Related to Age Awareness Among Middle-aged and Elderly Japanese

The purpose of this article was to expand past research by examining relationships between age awareness and related factors in Japanese middle-aged and elderly people. The subjects were 1,129 participants (575 men and 554 women, aged 40 to 79 years) of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA). They were examined with a questionnaire and interview. As a result, chronological age, self-rated health, and visual and hearing ability tend to be the related factors for awareness of aging. Comparing the demographic and physiological factors, however, major life events, difficulties and daily life experiences showed a stronger influence on age awareness. These results provide an interesting basis for the future understanding of adult development and the meaning of aging. J Epidemiol, 2000 ; 10 : S56-S62.


INTRODUCTION
Several researchers have found that older people are subjectively much younger than their actual age 1,2,3).Most of the elderly tend to consider themselves to be "middle-aged" or even "young", rather than "old" 2,4,).Older people's unwillingness to relinquish the middle-aged label and to assume an oldage identity is thought to be related to society's negative views of old age and older people 5,6).Indeed, stereotyped views of the elderly were associated with negative opinions, such as decline in power, productivity, social roles, and status 4).Therefore, awareness of aging (a sense of aging and being old) could be considered as a psychosocial crisis experienced in the middle-aged and elderly.Awareness of aging has been labeled in many ways as "age awareness", "age identification", "subjective age", and "perception of age", indicating that the concept in this research field has been so confused that it has been difficult to come to a clear and comprehensive understanding.
Investigators had sought to explain variations in subjective age by incorporating many variables in their analyses 3.7).Demographic and physiological indices of subjective age among older adults include chronological age 3,5,6,7,8,9) gender 3,4,5) education 3,10), socioeconomic status 9,11,12,13), marital status 3,6,14) family constitution 7,10), and health 3,5,6,8,9).Psychological functions reported in the previous studies regarding subjective age were life satisfaction 9,12), psychological health 13), locus of control 12,13) purpose in life 13), and self esteem 5,12).Major life events have also been considered as related factors that affect subjective age and age identification.For example, old people perceive themselves as elderly only after a severe loss of role, a decline in health, or a heightened awareness of impending death 15).Furthermore, the onset of old age is linked to personal or situational factors such as retirement from the work force 9,16), widowhood 9,17), and changes in income 16).Recently, some investigators have shifted their attention to include an analysis of daily events as important contributors to a people's experience of stress and distress in their lives 19,20,21).These daily events include chronic, recurrent, and minor aspects in contrast with major life events.In this study, difficulties and daily life experiences were examined as daily life events, distinct from major life events.Difficulties were defmed as the daily annoyances and nuisances of irritating or frustrating demands, whereas daily life experiences were defmed as changes from usual day-to-day occurrences.These types of difficulties and daily life experiences have been demonstrated to influence mental functions in old age.The effects of daily events are more pronounced than, and independent of, the effects of major life events as.Some studies have found a wide number of variables are associated with subjective age.However, there have been few studies designed to assess the multivariate relationships among these variables.
The purpose of this study was to expand past research examining relationships between awareness of aging and related factors in Japanese middle-aged and elderly people.In this study, the following correlates with subjective age were examined: (1) demographic and physiological indices, (2) psychological functions, (3) major life events, and (4) difficulties and daily life experiences.The present study took two approaches: first, the traditional subjective age correlates described above were reconfirmed as to their association with awareness of aging.Second, the relative impact among the factors that showed significant association with awareness of aging in the first study was examined.

Participants and Procedure
The subjects of this study were 1,129 adults randomly sampled from the local area in Aichi, Japan.They were the first wave participants in the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) from November, 1997 to March, 1999.The NILS-LSA is a new comprehensive longitudinal study, which started in 1997, to observe the normal aging process.The design, participants, measures, and procedures of the project have already been described elsewhere 23).The 1,129 participants consisted of 575 men and 554 women, aged between 40 and 79 years (Mean=58.8,SD=10.9).

Variables
Age awareness was tapped by the question "Do you feel you are getting older or aging now?" Responses were coded as 1 (Yes; being aware of aging) or 0 (No; not being aware of aging).
The following variables were adopted in the present study.Demographic and physiological variables , Actual chronological age: middle-aged (40-59 years) / older (60 years and over).Gender: male / female.Education: high school degree or better / others (elementary school and junior high school degree).Marital status: having a spouse / not having a spouse.Family constitution: having children / not having children.Self-rated health: good or fair / poor.Subjective hearing ability: good / bad.Subjective visual ability: good / bad.Responses to each question were dichotomized when analyzed.Psychological variables 1) Psychosocial development was measured using the Erikson Psychosocial Stage Inventory (EPSI) 24), a 5-point scale comprised of 56 items.Higher scores indicated higher levels of development or mastery.
2) Life satisfaction was assessed using the Life Satisfaction Index-K (LSI-K) developed by Koyano25).This scale consisted of 9 items with 2 or 3 options.Higher scores indicated higher levels of life satisfaction.
Items within each of the scales were summed up yielding median scores to classify subjects into two subgroups; a higher scored group and a lower scored group (EPSI: less than 190 / more than 191.LSI-K: less than 5 / more than 6).

Life events
Twelve major life events were adopted from the 62-item checklist used in the NILS-LSA.This checklist was based on the traditional life event lists.Participants were asked to check off or report the events they experienced in the past two years.The response format was coded as 1 (Yes; experience) or 0 (No; no experience).
The events analyzed in the study were: death of children, death of a spouse, traffic accident, death of a parent, major personal injury or illness, major change in the health of a family member, death of a close friend, retirement from work, getting a job (including restart of a job), son or daughter leaving home (marriage, attending college etc), spouse beginning or ceasing work outside the home, and gaining a new family member.Difficulties and Daily life experiences Chronic difficulties and daily life experiences items were also included in the checklist.Though most of these items were described as major life events in earlier studies (for example, Social Readjustment Scale 26) ), they could be defined as minor life stressors in the current study Zr, r.The response format was the same as that for major life events.
The study items were: trouble with children, trouble with friends, sexual difficulties, change in type and/or amount of recreation, change in social activities, change in sleeping habits, change in number of family get-togethers, and change in eating habits.

Statistical Analyses
Statistical significance for differences in categorical variables was evaluated using the chi-square test and Fisher's exact probability test.A multiple logistic regression analysis was performed to analyze the predictive power of each variable.Calculations of all data were performed with the SAS statistical package 28).

Bivariate analysis between awareness of aging and related factors
Table I shows the association between demographic and physiological variables and awareness of aging.Persons who felt their age tended to be older, female, low education, and HS=high school widow (or unmarried), compared with persons who did not.Also, the subjects who were aware of aging were more likely to have poor health and to report visual and hearing disability.However, there were no significant associations between age awareness and having children.
From the analyses of psychological variables, it was indicated that those with awareness of aging were characterized to be less satisfied with life and psychosocially less developed (Table 1).
The associations between major life events and awareness of aging are shown in Table 2.The results indicated that the number of subjects who experienced the major life events ("major change in health of a family member", "death of a close friend", and "getting a job") were significantly higher in the aware of aging group.
Table 2 also shows the association between difficulties and age awareness.In contrast to the major life events, all types of difficulties were related to awareness of aging.That is, subjects felt themselves being old when they had "trouble with children", "trouble with friends" and "sexual difficulties" .Likewise, daily life experience influenced age awareness.The subjects experiencing minor changes ("recreation", "social activities", "sleeping habits", "number of family get-togethers" and "eating habits") were more aware of aging than those who did not experience them.

Multiple Logistic regression analysis
The factors associated with awareness of aging in the univariate analyses above were entered into a multiple logistic regression model.The odds ratios (OR) and their 95 percent confidence intervals (95%CI) are shown in Table 3 .In general, the results showed stronger associations of major life events , Table 2.The relationship between awareness of aging and Life events, Difficulties and Daily life expariences.*Fisher's exact probability test difficulties and daily life experiences with age awareness than demographic, physiological or psychological variables.In particular, the odds ratio of "trouble with children" of persons who felt their aging was 3.57 (95%CI: 1.96-6.50)after adjustment for demographic, physiological and psychological variables.
This means that peoples who were aware of aging were about four times as likely to experience trouble or quarrels with children as those who were not aware of aging.The results also showed the odds ratio of "sex difficulties" (OR=2.79,95%CI: 1.12-6.98),"getting a job" (OR=2.59,95%CI:1.13-5.92),"change in sleeping habit s" (OR=1.95,95%CI:1.29-2.96),and "change in eating habits" (OR =1.86, 95%CI:1.21-2.87)were higher than that of chronological age.

DISCUSSION
This study first investigated previous insights about the relationship between awareness of aging and the traditional correlates, based on a large sample of middle-aged and elderly Japanese.Demographic variables had a significant impact on age awareness.Subjects who felt their age were chronologically old, female, less educated, and widow (or unmarried), but their family constitution was not different from the other subjects.Physiological variables also appeared to be correlated with age awareness.Subjects with poorer health and a visual or hearing disability were likely to feel themselves getting old.Older subjective age was found to be associated with poor health, since declining health made people dependent on others and took them a step closer to death 1.",16) .On the contrary, active, independent, and healthy persons didn't perceive themselves as "old" 29).Although recent data-based studies indicated there was no association between subjective age and gender 7.9.120, our study implied that women tend to be more aware of aging than men.One possibility supporting our findings is that there is a negative stereotype for old women .For example, Palmore concluded that our society viewed aging among women more negatively than aging among men 30).Some studies have supported the notion that women regard age differences more sensitively than men 1,4,5,) Marital status and education are also associated with age awareness.There is conflicting evidence in the literature on these variables 6, 9.13) .Although a few studies found a relationship between subjective age and having children 10.31, the present study did not find this relationship.
Life satisfaction and psychosocial development were examined in this study.These psychological variables were related to awareness of aging.A number of studies found a greater degree of life satisfaction among those who identified themselves as younger 7,9,12), which supported the results of our study.Though little empirical and immediate evidence has been produced concerning the relationship between psychosocial development and age awareness, several studies confirmed that better psychological functions are associated with younger age perception in the elderly 12,32).
Life crisis has often been associated with the mental wellbeing of the elderly 33).Some previous studies showed that "retirement" 9,16) and "widowhood" 9,17) were predictors for people perceiving themselves as "old".In this and other studies, however, "retirement" 14) and "widowhood" 6,13) were not related factors in awareness of aging.Rather, "change in the health of a family member", "death of a close friend", and "getting a job" were the major life events that were significantly related to age awareness."Change in the health of a family member" and "death of a close friend" were the events many subjects experienced.However, very few subjects experienced the death of a spouse or children.Although experiencing "death of a spouse or children" and "departure of children" are assumed to be associated with age identification 9,34,), the lower experience rate may have caused the underestimation of the significance of these events as age identity correlates.Therefore, the results of this study should be interpreted cautiously.Previous researches confirmed the impact of "retirement from work" as a risk factor of an older self-identification 9, 16).However, our results indicated that "getting a job" was a related factor of age awareness.This suggests that those who completely retired didn't need to get a new job, since they could maintain the same living standards as that before retirement with a pension or their savings.Thus, the retirement implies a freedom from their job roles and didn't become a predictor of age awareness.In contrast, those who started working again could have been forced to work due to financial difficulties.Furthermore, work stress also may promote age awareness as a change of work usually means demotion in Japan.
Contrary to the results for major life events, all difficulties and daily life experiences were related to awareness of aging.Turner & Wheaton advocated the specification of events as a separate realm, distinguished from other sources of and types of stress, so that the relative importance of the different types of stress could be compared 35).As difficulties and daily life experiences that is linked to a pattern of discontent in a person-'s life may be the most likely to trigger psychological disturbance 21,22), future research should examine awareness of aging by distinguishing difficulties and daily life experiences from major life events.
In the second analysis, the relative impact among age aware-ness correlates was examined.Consistent with previous studies, chronological age, self-rated health, and visual and hearing ability tended to be related factors in the awareness of aging.Those who felt their age were significantly different from others in terms of the experiences of "getting a job", "trouble with children", "sex difficulties", "change in sleeping habits", and "change in eating habits" .Compared to demographic and physiological factors, however, major life events, difficulties and daily life experiences showed a relatively strong influence on age awareness.These findings support the argument that psychological events are more important as age awareness correlates than physiological experiences 34, 36).Moreover, difficulties and daily life experiences had a stronger impact than major life events on awareness of aging.Though it has been emphasized that major life events have an impact on subjective age, the results of this study suggest that chronic and daily stressors could also play an important role in getting aware of aging.
Although it has been pointed out that major life events and social traumas promote senility, little is known about the process in which age awareness is influenced by major life events.For example, no conclusive evidence exists concerning the relationship between either marital status or widowhood and self-perceived age 3,13).Although several studies found widowhood to be associated with self-identification as old 9), this association typically disappeared when chronological age was controlled 6).This example highlighted the complex relationships between subjective age and correlates.In our study, some of the variables that indicate a significant relationship with awareness of aging in the first univariate analyses did not have enough predictive power when estimated in a multivariate analysis.We intend to continue longitudinally designed analyses to clarify the factors involved in a change in age awareness.Moreover, it is not clear what type of difficulties and daily life experiences predicts senility.Future research should also include longitudinal assessments of the relative impact of the difficulties and daily life experiences.
In summary, chronological age, self-rated health, and visual and hearing ability were the related factors of age awareness.Compared with the demographic and physiological factors, however, major life events, difficulties and daily life experiences showed a stronger influence on awareness of aging.Our findings provide an interesting basis for the future understanding of adult development and the meaning of aging.

Table 1 .
The relationship between awareness of aging and demographic, physiological and psychological variables.

Table 3 .
Results of multiple logistic regression model to evaluate the effect of four domain factors on awareness of aging.