A comparison of perceived uselessness between centenarians and non-centenarians in China

Evidence from various populations has indicated that a strong sense of usefulness to others among older adults plays a crucial role in shaping positive views about their own aging, health behaviors and adequate adaptations that contribute positively to their good health and psychological wellbeing, and even longevity [1‐15]. By contrast, perceiving one’s life as useless is associated with higher prevalence of chronic diseases [16, 17], poorer cognitive function and mental health status [7, 18‐20], poorer self-rated health and life satisfaction [7, 21‐24], lower physical functioning [5‐7, 11, 25], and higher risk of mortality [6, 8, 10, 15, 26‐29]. Perceptions of uselessness are also linked with higher levels of depression and lower levels of social and physical activity engagements, self-efficacy and self-esteem [5, 6, 11]. Although these studies have enriched our understanding about the associations between self-perceived uselessness and health behaviors, psychological wellbeing, and health outcomes [7, 30], most of these studies focused on general populations of older adults. It is less clear whether low levels of perception of uselessness still play a crucial role at very old age in helping long-lived persons reach successful aging and healthy longevity. Given the statistical robustness of self-perceived uselessness in affecting behaviors and in predicting health outcomes in the existing literature [7, 15, 30], it thus may have important implications for public health interventions to study self-perception of uselessness among centenarians and compare it with that of non-centenarian older adults.

Centenarians are often considered as the best age group to study healthy longevity and successful aging [31, 32]. Although centenarians show a poorer physical health and cognitive function compared to younger older adults [31‐35], their psychological wellbeing may not be in disadvantage [32, 36]. More importantly, evidence shows that in comparison with their same cohort peers, centenarians are more psychologically resilient and have higher levels of physical and cognitive function than those who died younger [32, 36, 37].

Researchers generally agree that there is a large variation in disease conditions, physical/cognitive functions, and psychological wellbeing among these long-lived individuals [31, 35, 38], and that centenarians may follow a different trajectory of health decline from those non-centenarians [32]. Thus, the significance of comparison of self-perception of uselessness between centenarians and non-centenarians cannot be undervalued. Yet, studies about centenarians’ own views on aging or self-perceived usefulness are virtually nonexistent in the literature. Do centenarians have a more positive perception about their usefulness than their younger counterparts? And if so, what are the factors that could explain the differences? To our knowledge, there is currently no study available to address these research questions, possibly due to unavailability of data. This present study thus aims to investigate these research questions using the largest centenarian sample in the contemporary world from a nationwide longitudinal survey in mainland China.

Table 1 presents the percentage distribution of study variables by the frequency of self-perceived perception of uselessness for 48,476 observations collected in 2005–2014 from 26,624 participants. A smaller proportion of the centenarians reported high frequency of self-perceived uselessness compared to non-centenarians, yet centenarians had a much higher proportion of “unable to answer”. Among the 2921 individuals who were born in 1906–1913 included in the cohort analysis, those who became centenarians in 2005–2014 had a higher proportion of the low frequency of self-perceived uselessness compared to those who died between ages 91 and 99 in 2005–2014.

Table 2 presents the relative risk ratios (RRRs) of reporting high and moderate frequencies versus the low frequency of self-perceived uselessness for centenarians as compared to older adults in other age groups from the period analysis. Model I reveals that although centenarians had no difference in self-perceived uselessness compared to octogenarians and nonagenarians when only demographics were controlled for, they were respectively associated with 84% (RRR = 1.84, 95% CI: 1.69–2.01) and 35% (RRR = 1.35, 95% CI: 1.25–1.46) higher risk of reporting the high and the moderate frequencies of self-perceived uselessness relative to the low frequency in comparison with older adults aged 65–79. Model II shows that the elevated RRRs were mildly attenuated to 52% (RRR = 1.52, 95% CI: 1.39–1.67) and 23% (RRR = 1.23, 95% CI: 1.13–1.33), respectively, when resources were added to Model I; and Model III shows that these RRRs were 56% (RRR = 1.56, 95% CI: 1.42–1.72) and 21% (RRR = 1.21, 95% CI: 1.11–1.31), respectively, when social environmental factors were included in Model I. So far, modeling results reveal that centenarians were more likely to perceive themselves as useless compared to the youngest older adults aged 65–79 and had no difference in self-perceived uselessness as compared to older adults aged 80–99.

However, when behavioral factors were controlled in addition to demographics (Model IV), centenarians had 25% (RRR = 0.75, 95% CI: 0.69–0.82) and 15% (RRR = 0.85, 95% CI: 0.78–0.93) lower risk ratios of having the high frequency of self-perceived uselessness relative to the low frequency compared to octogenarians and nonagenarians, respectively, although they still had a 11% higher risk ratio of having the moderate frequency relative to low frequency of self-perception of uselessness than older adults aged 65–79. When ADL disability and cognitive impairment were controlled for in addition to demographics (Model V), the centenarians were 34% (RRR = 0.66, 95% CI: 0.60–0.72) and 22% (RRR = 0.78, 95% CI: 0.71–0.85) less likely than octogenarians and nonagenarians to have the high frequency of self-perceived uselessness relative to the low frequency. The corresponding figures for the moderate relative to the low frequency of self-perception were 11% (RRR = 0.89, 95% CI: 0.82–0.96) and 9% (RRR = 0.91, 95% CI: 0.85–0.99).

When all covariates were taken into consideration, centenarians had 31% (RRR = 0.69, 95% CI: 0.54–0.88), 43% (RRR = 0.57, 95%CI: 0.49–0.68), and 25% (RRR = 0.75, 95%CI: 0.67–0.83) respectively lower risk ratios of having the high frequency relative to the low frequency of self-perceived uselessness compared to older adults aged 65–79, 80–89, and 90–99. In the case of the moderate frequency relative to the low frequency, these reduced risk ratios were 18% (RRR = 0.82, 95% CI: 0.66–1.02), 22% (RRR = 0.78, 95% CI: 0.67–0.90), and 13% (RRR = 0.87, 95% CI: 0.79–0.96), respectively. These results of the sequential models indicate that all sets of factors played a certain role in distinguishing the self-perception of uselessness between centenarians and older adults at other age groups, but health practice and health conditions played a greater role than other factors.

In the case of the cohort analysis among those who were born in 1906–1913 and survived to age 91 or above, Table 3 shows that compared with those who died at ages 91–94, those who became centenarians were 36–39% less like to have the high and the moderate frequencies of self-perceived uselessness versus the low frequency when demographic factors plus either resources factors or social environmental factors were taken into account. When the participation in leisure activities or the health condition was taken into consideration, the relative risk of the high frequency versus the low frequency of self-perceived uselessness among centenarians was not statistically significant compared with those who died at age 91–94, although the RRR was significant in the case of the moderate frequency versus the low frequency controlling for health behaviors and demographics (Model IV). In other words, when participation in leisure activities and health condition of those who died at age 100 or beyond was the same as those who died at ages 91–94, there would have no difference in self-perceived uselessness between these two groups. In our sample, those who died at age 100 or beyond were in better health and were more likely to participation in leisure activities (not shown). When all factors were controlled for, there was only a very slight change in RRRs (Model VI) compared to the model that controlled for health (Model V). These results suggest that all factors under study other than participation in leisure activities and health conditions had a little impact on differentiating self-perception of uselessness between centenarians and those died at ages 91–94. This implies that participation in leisure activities and health condition played a greater role than other factors in differing those who lived to age 100 from those from the same birth cohort who died earlier in 2005–2014. No significant difference was found between those who died at age 100 or older and those who died at ages 95–99.

Based on the 2005, 2008, 2011, and 2014 four waves of the Chinese Longitudinal Healthy Longevity Survey, the largest nationally representative survey of older adults in China, we examined whether centenarians were less likely to perceive themselves as useless compared to younger cohorts. In general, we found that when only demographic attributes, socioeconomic resources, and social environmental factors were taken into consideration, centenarians had a higher proportion of having a negative self-perception about their own usefulness than younger generations aged 65–79, although the centenarians had a similar proportion compared to octogenarians and nonagenarians. However, when behavioral factors or heath conditions were taken into account, centenarians were less likely to have a perception of self-perceived uselessness than octogenarians and nonagenarians; and when all factors under study were controlled for, centenarian were also less likely to have a negative perception about their usefulness compared to all four younger age groups under study. More importantly, we further found from the cohort analysis of those born in 1906–1913 that in comparison with those who were from the same cohort but died at ages 91–94, those who became centenarians were less likely to perceive themselves as useless when demographic attributes, resource factors, and social environmental factors were controlled for. Overall, these results convey a clear message that centenarians hold more positive attitudes and views about their aging than non-centenarians, and that these positive views may attribute to better chances for survival.

One important finding of the present study is that health in terms of physical and cognitive functions and behaviors played a more important role than other factors in distinguishing the self-perceive uselessness between centenarians and non-centenarian older adults. Health behaviors were measured by leisure activities, which is closely related physical function. This finding provides additional evidence to support the contribution of health and active lifestyle to self-perception about one’s views and attitudes toward aging or usefulness. Studies have shown that a good health condition is associated with a better self-perception about one’s usefulness to family and others [30]. Our findings also enrich the existing literature on factors associated with self-perceived usefulness and self-perception of aging [15] and the literature on centenarians’ positive psychological attributes [26].

Research has indicated that perceptions of usefulness or uselessness may impact one’s health psychologically, behaviorally, and physiologically [7, 14, 15]. Physiologically, having a strong feeling of usefulness could avoid a dysregulation of the central nervous system, neurotransmitters, and/or immune system for the onset and progression of disease, disability, and other manifestations of aging [46, 47]. Behaviorally, positive views and attitudes about one’s aging could maintain healthy lifestyles that promote health [5]. Psychologically, a strong sense or perception about own usefulness to others could avoid diminishment of beliefs about self-control and self-efficacy, help prevent social isolation, and improve resilience capacity to deal with negative views/thoughts and difficulties in daily life [5, 15, 48].

It is possible that with increasing age, some very old adults, especially centenarians have developed strategies to cope with challenges and changes in their environments so that the sense of perceived usefulness to family, others, and society is maintained [6, 32, 49‐52]. Some previous studies have shown that a fairly large portion of centenarians are still in a good function [35], that vast majority of centenarians are quite independent in performing daily activities when they were at early 90s [38], and that they are more psychologically resilient than younger peers of the same birth cohort, or even as resilient as those younger birth cohorts [32, 50]. Overall, our findings are generally in accordance with previous findings that centenarians were more physically and psychologically robust than nonagenarians of their same birth cohorts in handling stress, depression, or other unfavorable conditions than their cohort peers [32, 36‐38, 50]. The lower levels of self-perceived uselessness among the centenarians imply that positive attitudes and views about aging may be an important pathway to reach age 100.

Our finding that centenarians are less likely to feel useless to family and others compared to their cohort peers underscores the importance of maintaining positive self-perceptions with age at an individual level and suggests that it may never be too late to promote positive perspectives of aging [30]. In order to achieve exceptional longevity, it is thus recommended to promote positive views and attitudes among older people by building and maintaining adequate emotional capacity, neutralizing negative emotionality, developing resistance to counteract negative age-associated stressors, and nurturing positive views of health and life [53, 54]. Given recent evidence on the negative perceptions of aging among older adults in China [55], and eroding practice of filial piety and respecting for older adults due to rapid social and economic changes [7, 56, 57], promoting positive views about one’s own aging and creation of age-friendly environments are especially timely and needed so as to achieving successful aging [58].

While highlighting the strengths, we acknowledge the following limitations. First, the CLHLS only used a single item to collect data on self-perceived uselessness, which may not capture the multidimensionality of the concept of uselessness [15, 28]. Second, because the CLHLS is not designed to be a cohort study, the sample size at each individual age only consists of a couple of hundred participants, which may be not sufficient in follow-up wave due to high mortality among these participants, although the total sample size is relatively large. Furthermore, the follow-up length only lasted for 10 years in the present study, which is a relatively short follow-up period. In addition, in our cohort analysis, more than 60% of the samples were aged 95–99 at the time of their initial interview and more than 85% of those who did not live to age 100 died at age 95–99. In other words, our cohort results mainly refer to a comparison between those aged to 95–99 years old and those who became centenarians. Overall, larger sample size and longer follow-up period are warranted to have more robust results. Third, although we examined factors associated with self-perceived uselessness for centenarians in comparison with non-centenarians and found that centenarians were more likely to have a low frequency of self-perceived uselessness compared with their same birth cohort peers who did not become centenarians. However, the casual mechanism responsible for how such positive attitudes or perceptions have enhanced their healthy longevity deserves further investigations. Studies combining phenotypic and genotypic data and adopting an interdisciplinary perspective may be a promising area for further explorations. Fourth, studies have shown that people may change their perception of age over time [59]. It is thus possible that the sense of longevity may influence their perceived usefulness, either negatively or positively, when they live longer and longer. Yet it is unknown whether, how, and to what extent aging itself or longevity can improve positive perception about own usefulness. We welcome more studies to shed light onto better understanding of the underlying mechanism of positive perception and longevity. Finally, although to our knowledge the present study is the first to investigate centenarians’ own perceptions about their usefulness in comparison with those of non-centenarians, many factors that moderate or mediate the association between self-perception of usefulness, and other factors such as psychosocial and biological traits that are important factors in linking self-perceptions of aging with longevity were not included in the analyses [60]. We hope that in the future more studies will investigate the underlying mechanism between self-perceptions of own aging and longevity.

Based on a large nationally representative multi-wave survey of older adults in China from 2005 to 2014, we found that centenarians were less likely to have a negative perception about their own usefulness compared with younger elders when holding other personal characteristics and conditions equal and compared with those non-centenarian peers of their own birth cohorts. Our findings provided additional evidence to support the notion that centenarians are more positive about their aging. The results from this study could broaden our understanding of how internalized perceptions of aging could have significant consequences for the survival and longevity of older adults in a rapidly aging society.