Which Factors do Older Adults Consider When Estimating the Time Left for Them to Live?

Which Factors do Older Adults Consider When Estimating the Time Left for Them to Live? Abstract Objectives The present study examines which factors older adults consider as important when rating their subjective nearness-to-death (SNtD), as well as the associations between corresponding variables as reported in a multidimensional questionnaire and responses on a SNtD question. In addition, we examine whether importance ratings fit or diverge from the actual associations between corresponding variables and SNtD. Method Two hundred and seventy-two participants (average age 80.75) reported their health and functioning, their SNtD, and the importance of each of 13 preselected factors in evaluating SNtD. Results Respondents considered physical functioning and psychological factors as the most important factors to their SNtD evaluation, and genetic factors (i.e., age, gender, parental longevity) as the least important. Ratings of importance were strongly and positively correlated with the strength of the associations between the corresponding variables and SNtD. Discussion Older adults appear to have implicit knowledge of the factors that affect their SNtD. Yet, this knowledge is sometimes biased and does not necessarily represent variables that have been identified as related to actual longevity. End-of-life evaluations, Perceptions of aging, Subjective nearness-to-death Human beings have the unique cognitive ability to mentally travel in time and to prepare for the future (Mulcahy & Call, 2006). Perceptions of the time left to live serve to understand one’s current emotional state and to make prospective plans (Carstensen, 2006; Lang, 2000). It has been suggested that individuals construct an internal mental model that incorporates and integrates information regarding the time that they estimate they have until death (Griffin, Loh, & Hesketh, 2013; Hesketh, Griffin, & Loh, 2011). This model is based on evaluations of genetic factors (e.g., age, gender, parents’ age at death), socioeconomic factors (e.g., education, financial status, marital status), health conditions (e.g., chronic disease, cognitive functioning), physical functioning (e.g., energy, activity), and psychological factors (e.g., optimism, depressive thoughts). When estimating their remaining time, individuals likely consider some or all of these factors but they do not necessarily assign the same weight to each factor. Relatively few empirical studies have examined the variables that actually associate with subjective nearness-to-death (SNtD). Prior research shows that demographic characteristics, physical condition and functioning, and psychological variables predict SNtD (Bergman, Bodner & ,Haber, 2018; Griffin et al., 2013; Hoppmann, Infurna, Ram, & Gerstorf, 2015; Kotter-Grühn, Grühn, & Smith, 2010; Palgi et al., 2014; Shrira, Bodner, & Palgi, 2014). However, individuals have yet to directly report what affects their evaluations of SNtD or to rate the relative importance of the various factors that affect their evaluations. Benyamini, Leventhal, and Leventhal (1999, 2003) assessed the factors that affect self-rated health, and found that the perceived time left to live was among the least important factors in evaluating health. In contrast, Griffin et al. (2013) reported a moderate correlation between self-rated health and SNtD. These findings indicate that self-rated health and SNtD represent related but different constructs (Kotter-Grühn et al., 2010). It is thus possible that SNtD is determined by other factors than the ones that affect ratings of health. In the current study, we followed Benyamini et al.’s (1999, 2003) method in order to investigate which factors older adults consider important when reporting their SNtD. Accordingly, we asked participants to rate the importance of various factors when reporting their SNtD (henceforth “importance ratings”). We further assessed the correlations between variables corresponding to these factors and SNtD (e.g., whether importance rating of chronic disease corresponds with the correlation between the number of chronic diseases and SNtD). We then ranked the factors according to importance ratings, and ranked the correlations between the corresponding variables and SNtD according to their strength. Our main hypothesis was that the rank of importance ratings would positively associate with the rank of correlations between corresponding variables and SNtD. This hypothesis is based on the assumption that individuals incorporate and integrate personal information regarding factors that influence their SNtD through direct observations (e.g., those who live longer had parents who lived to an old age), media (e.g., more women appear in commercials for older adults), public health campaigns (e.g., physical activity is beneficial to one’s health), or other available information (Griffin et al., 2013). In addition, following associations found in previous studies between SNtD-related constructs and various variables (e.g., Griffin et al., 2013), the second hypothesis is that health condition and psychological factors (e.g., chronic disease, optimism) will be the most strongly related to SNtD, whereas socioeconomic factors (e.g., education, financial status, marital status) will be the least related to SNtD. Although perceptions of the time left to live help individuals plan their entire life, evaluations might be imprecise. Thus, we also examine whether there are specific factors that individuals report as important to their evaluations but which have low associations with SNtD, or whether factors that are considered unimportant still have strong associations with SNtD. Method Sample and Procedure The sample included 272 older adults living in nursing homes or the community. Participants were 80.75 years old on average (SD = 6.52, range 65–97), primarily female (N = 202, 74%), and more than half were widows (N = 141, 52%). They were interviewed by trained research assistants in their homes or in a quiet area of public places such as a community center. Each interview lasted approximately 1 hr. The study received Institutional Review Board approval. Measures Subjective nearness-to-death (SNtD) was assessed with a single item “I have the feeling that my life is approaching its end” (based on Kotter-Grühn et al., 2010). Participants rated whether they agreed with this item on a 5-point scale (1 = not at all, 5 = very much). Genetic variables Age and gender were recorded in order to examine whether they were connected to SNtD, as found before (Griffin et al., 2013). Parental longevity was assessed by asking individuals to report their parents’ age at death (van Solinge & Henkens, 2010). Socioeconomic variables Financial status was measured by self-report of household income, using a single item “How would you define your financial condition?.” Participants rated this item on a 5-point scale (1 = not good at all, 5 = very good). We also recorded marital status and years of education. Health condition We examined health conditions by a checklist of nine chronic diseases and physiological symptoms (Litwin & Sapir, 2008; Shrira et al., 2011). This measure was scored by the sum of checked medical conditions (e.g., cancer, heart disease, diabetes) that participants reported they have been diagnosed with. Participants were also asked to report whether they had any memory difficulties, using eight statements about cognitive abilities (Pearlin, Mullan, Semple, & Skaff, 1990). Each statement was rated on a 5-point scale (1 = not difficult at all, 5 = very difficult). Physical functioning Disability was assessed by asking participants to report activities of daily living (ADL; Katz, Downs, Cash, & Grotz, 1970) and instrumental ADL (IADL; Lawton & Brody, 1969). These scales included 13 items and participants were asked to say Yes or No if they experienced difficulty on any item. Kudder-Richardson was 0.81. In addition, we examined the level of energy, using a single question “Do you feel full of energy?” (Yes or No), taken from the Geriatric Depression Scale (Almeida & Almeida, 1999). Psychological variables Optimism was examined by the three-item optimism subscale in the Life Orientation Test (LOT-R; Scheier, Carver, & Bridges, 1994). Participants rated the items using a 5-point scale (0 = disagree, 4 = completely agree). The alpha coefficient was 0.71. Depressive thoughts were measured with a single item from the Big-Five questionnaire, “Do you feel sad or depressed” (John & Srivastava, 1999). Responses were provided on a 4-point scale (1 = completely disagree, 4 = completely agree). Rating the importance of factors that affect NtD estimation At the end of the questionnaire, participants were asked to rate how important was each of the 13 randomly arranged, preselected factors to their evaluation of their own NtD on a 5-point scale (1 = not important at all, 5 = very important). This evaluation was conducted at the end of the session in order to prevent possible influence on the questionnaire itself, and to help participants reflect upon the factors that they consider important when evaluating their SNtD. Results Most participants (265, 97.4%) rated their SNtD. One-hundred and twenty-six participants (47.5%) reported that they did not feel close to their death at all, 47 (17.7%) felt rather far from death, 48 (18.1%) felt close to death to a moderate degree, 31 (11.7%) felt quite close to death, and only 13 (4.9%) felt very close to death. Participants ranked physical functioning and energy as the most important factors in evaluating SNtD, and gender and parents’ age at death as the least important factors (see Table 1). The means of these ratings were used to rank order the 13 factors, so that items that participants rated as most important received the highest ranking. Table 1. Descriptive Statistics and Ranking of Factors’ Importance Ratings and Correlations between Corresponding Variables and SNtD Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Note: Maximum N = 272. ADL = Activities of daily living; IADL = instrumental ADL; SNtD = Subjective Nearness to Death; n.s.= not significant. *p < .05, **p < .01, ***p < .001. View Large Table 1. Descriptive Statistics and Ranking of Factors’ Importance Ratings and Correlations between Corresponding Variables and SNtD Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Note: Maximum N = 272. ADL = Activities of daily living; IADL = instrumental ADL; SNtD = Subjective Nearness to Death; n.s.= not significant. *p < .05, **p < .01, ***p < .001. View Large Next, we computed the correlation between each corresponding variable and SNtD ratings, and then rank-ordered these correlations according to r level. This analysis showed that the correlations of optimism and energy with SNtD were highest, and the correlations of gender and father’s age at death with SNtD were lowest. The two sets of ranks (the rank of factor importance ratings and the rank of correlations of corresponding variables) were strongly and positively associated with each other (Spearman’s Rho [ρ] = .81, p < .01). A further analysis that included only the seven corresponding variables that were significantly associated with SNtD yielded similar results (ρ = .82, p < .05). Evaluating the rank of categories by averaging the ranks of relevant factors showed that the physical functioning category was ranked the most important, followed by the psychological, health condition, and socioeconomic categories, whereas the genetic category was ranked as the least important. Discussion In line with our first hypothesis, our findings show a strong association between ranking of importance ratings and ranking of correlations between corresponding variables and SNtD, as found before for self-rated health (Benyamini et al., 1999, 2003). These results support the assumption that factors that individuals consider important when thinking of the time left for them to live are indeed similar to the corresponding variables that correlate with SNtD. Thus, individuals may have an internal mental model (Mulcahy & Call, 2006) that helps them estimate the time left to live, and may arrange their current and future life in accordance with this estimate (Carstensen, 2006; Griffin et al., 2013; Hesketh et al., 2011). In line with our second hypothesis, individuals considered the physical functioning and psychological categories as the most important factors in determining their SNtD evaluation. We hypothesized that socioeconomic factors (i.e., education, financial status, and marital status) would be considered the least important, and these factors were indeed rated as lower in importance than others. However, some genetic factors (i.e., gender and parental longevity) were considered the least important. Although it is easy to understand why physical activity was interpreted as important to the time left to live, it is not obvious why genetic factors were considered less important to this evaluation. This surprising finding needs further investigation in order to better understand the mechanism that underlies these evaluations. Moreover, there were several specific factors that individuals rated as important for their SNtD estimations, for which only low correlations were found between the associated corresponding variables and SNtD. For example, marital status was considered important when rating SNtD but it was poorly associated with SNtD. Furthermore, there were some factors that were placed similarly in both rankings but that did not reflect their real effect on age of death, as reported in earlier studies. That is, several health and genetic factors, such as mother’s age at death or the presence of a chronic disease, were ranked low in both ratings, although research suggests that they are important predictors of age at death (Rantanen et al., 2012). One possible explanation is that many of our participants lost their parents at a young age due to the Holocaust and therefore were not looking at parents’ age at death as reflecting their potential longevity. Even when we examined participants who were still younger than their parents’ age at death, parental longevity was not an important predictor of SNtD. Another possible explanation is that people are more influenced by their immediate status (physical functioning and energy) than by remote factors such as parental longevity. We calculated the correlation between parental age at death and SNtD separately for those who are now older than their parents were when they died and for those who are now younger than their parents were when they died. The correlations were low and nonsignificant for both groups (r = .09 and .01 for those who are now younger and for those who are now older than their father was when he died, respectively; r = −.06 and .13 for those who are now younger and for those who are now older than their mother was when she died, respectively). When examining importance ratings for parental age at death, it was 2.93 (SD = 1.47) and 2.24 (SD = 1.45) for those who are now younger and for those who are now older than their father was when he died, respectively (t[233] = 3.41, p < .01), and 3.04 (SD = 1.49) and 2.27 (SD = 1.47) for those who are now younger and for those who are now older than their mother was when she died, respectively (t[237] = 4.02, p < .001). Although importance ratings significantly differed between the two groups, they were lower (between 2.24 and 3.04) than were importance ratings of most other factors. On the other hand, psychological factors were ranked high in both ratings, although they are known to have only low-to-moderate effect in predicting age at death, especially in old-old age (e.g., Ben-Ezra & Shmotkin, 2006; Maier & Smith, 1999). Therefore, in general, older adults have a rather accurate awareness of the factors that correlate with their perception of the time left to live, yet these perceptions might be biased in some cases. Future longitudinal studies that will take actual longevity into consideration could shed light on these discrepancies. Our study has some limitations. First, a more comprehensive list of factors could have changed the importance attributed to each of them. Yet, our results resemble previous findings reported by Benyamini et al. (1999, 2003) regarding self-rated health, suggesting that the number of factors was sufficient in revealing participants’ implicit knowledge. In addition, it is possible that the order of questions (e.g., asking about importance immediately after evaluating each factor) might have affected the correlations. Second, we did not evaluate time to death in years, and future studies would have to assess this issue as well. In sum, this study is the first to examine the factors that individuals consider when estimating how much time they have to live. Our findings show that although individuals are generally aware of the factors that affect nearness to death, they are biased with regards to specific factors. These results may help practitioners who work with older adults in guiding their clients toward the formulation of informed decisions. Funding This work was supported by the Israel Science Foundation (ISF; grant number 1234/14). Conflict of Interest None reported. References Almeida , O. P. , & Almeida , S. A . ( 1999 ). 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European Journal of Public Health , 20 , 47 – 51 . doi: 10.1093/eurpub/ckp118 Google Scholar CrossRef Search ADS PubMed © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journals of Gerontology Series B: Psychological Sciences and Social Sciences Oxford University Press

Which Factors do Older Adults Consider When Estimating the Time Left for Them to Live?

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Abstract

Abstract Objectives The present study examines which factors older adults consider as important when rating their subjective nearness-to-death (SNtD), as well as the associations between corresponding variables as reported in a multidimensional questionnaire and responses on a SNtD question. In addition, we examine whether importance ratings fit or diverge from the actual associations between corresponding variables and SNtD. Method Two hundred and seventy-two participants (average age 80.75) reported their health and functioning, their SNtD, and the importance of each of 13 preselected factors in evaluating SNtD. Results Respondents considered physical functioning and psychological factors as the most important factors to their SNtD evaluation, and genetic factors (i.e., age, gender, parental longevity) as the least important. Ratings of importance were strongly and positively correlated with the strength of the associations between the corresponding variables and SNtD. Discussion Older adults appear to have implicit knowledge of the factors that affect their SNtD. Yet, this knowledge is sometimes biased and does not necessarily represent variables that have been identified as related to actual longevity. End-of-life evaluations, Perceptions of aging, Subjective nearness-to-death Human beings have the unique cognitive ability to mentally travel in time and to prepare for the future (Mulcahy & Call, 2006). Perceptions of the time left to live serve to understand one’s current emotional state and to make prospective plans (Carstensen, 2006; Lang, 2000). It has been suggested that individuals construct an internal mental model that incorporates and integrates information regarding the time that they estimate they have until death (Griffin, Loh, & Hesketh, 2013; Hesketh, Griffin, & Loh, 2011). This model is based on evaluations of genetic factors (e.g., age, gender, parents’ age at death), socioeconomic factors (e.g., education, financial status, marital status), health conditions (e.g., chronic disease, cognitive functioning), physical functioning (e.g., energy, activity), and psychological factors (e.g., optimism, depressive thoughts). When estimating their remaining time, individuals likely consider some or all of these factors but they do not necessarily assign the same weight to each factor. Relatively few empirical studies have examined the variables that actually associate with subjective nearness-to-death (SNtD). Prior research shows that demographic characteristics, physical condition and functioning, and psychological variables predict SNtD (Bergman, Bodner & ,Haber, 2018; Griffin et al., 2013; Hoppmann, Infurna, Ram, & Gerstorf, 2015; Kotter-Grühn, Grühn, & Smith, 2010; Palgi et al., 2014; Shrira, Bodner, & Palgi, 2014). However, individuals have yet to directly report what affects their evaluations of SNtD or to rate the relative importance of the various factors that affect their evaluations. Benyamini, Leventhal, and Leventhal (1999, 2003) assessed the factors that affect self-rated health, and found that the perceived time left to live was among the least important factors in evaluating health. In contrast, Griffin et al. (2013) reported a moderate correlation between self-rated health and SNtD. These findings indicate that self-rated health and SNtD represent related but different constructs (Kotter-Grühn et al., 2010). It is thus possible that SNtD is determined by other factors than the ones that affect ratings of health. In the current study, we followed Benyamini et al.’s (1999, 2003) method in order to investigate which factors older adults consider important when reporting their SNtD. Accordingly, we asked participants to rate the importance of various factors when reporting their SNtD (henceforth “importance ratings”). We further assessed the correlations between variables corresponding to these factors and SNtD (e.g., whether importance rating of chronic disease corresponds with the correlation between the number of chronic diseases and SNtD). We then ranked the factors according to importance ratings, and ranked the correlations between the corresponding variables and SNtD according to their strength. Our main hypothesis was that the rank of importance ratings would positively associate with the rank of correlations between corresponding variables and SNtD. This hypothesis is based on the assumption that individuals incorporate and integrate personal information regarding factors that influence their SNtD through direct observations (e.g., those who live longer had parents who lived to an old age), media (e.g., more women appear in commercials for older adults), public health campaigns (e.g., physical activity is beneficial to one’s health), or other available information (Griffin et al., 2013). In addition, following associations found in previous studies between SNtD-related constructs and various variables (e.g., Griffin et al., 2013), the second hypothesis is that health condition and psychological factors (e.g., chronic disease, optimism) will be the most strongly related to SNtD, whereas socioeconomic factors (e.g., education, financial status, marital status) will be the least related to SNtD. Although perceptions of the time left to live help individuals plan their entire life, evaluations might be imprecise. Thus, we also examine whether there are specific factors that individuals report as important to their evaluations but which have low associations with SNtD, or whether factors that are considered unimportant still have strong associations with SNtD. Method Sample and Procedure The sample included 272 older adults living in nursing homes or the community. Participants were 80.75 years old on average (SD = 6.52, range 65–97), primarily female (N = 202, 74%), and more than half were widows (N = 141, 52%). They were interviewed by trained research assistants in their homes or in a quiet area of public places such as a community center. Each interview lasted approximately 1 hr. The study received Institutional Review Board approval. Measures Subjective nearness-to-death (SNtD) was assessed with a single item “I have the feeling that my life is approaching its end” (based on Kotter-Grühn et al., 2010). Participants rated whether they agreed with this item on a 5-point scale (1 = not at all, 5 = very much). Genetic variables Age and gender were recorded in order to examine whether they were connected to SNtD, as found before (Griffin et al., 2013). Parental longevity was assessed by asking individuals to report their parents’ age at death (van Solinge & Henkens, 2010). Socioeconomic variables Financial status was measured by self-report of household income, using a single item “How would you define your financial condition?.” Participants rated this item on a 5-point scale (1 = not good at all, 5 = very good). We also recorded marital status and years of education. Health condition We examined health conditions by a checklist of nine chronic diseases and physiological symptoms (Litwin & Sapir, 2008; Shrira et al., 2011). This measure was scored by the sum of checked medical conditions (e.g., cancer, heart disease, diabetes) that participants reported they have been diagnosed with. Participants were also asked to report whether they had any memory difficulties, using eight statements about cognitive abilities (Pearlin, Mullan, Semple, & Skaff, 1990). Each statement was rated on a 5-point scale (1 = not difficult at all, 5 = very difficult). Physical functioning Disability was assessed by asking participants to report activities of daily living (ADL; Katz, Downs, Cash, & Grotz, 1970) and instrumental ADL (IADL; Lawton & Brody, 1969). These scales included 13 items and participants were asked to say Yes or No if they experienced difficulty on any item. Kudder-Richardson was 0.81. In addition, we examined the level of energy, using a single question “Do you feel full of energy?” (Yes or No), taken from the Geriatric Depression Scale (Almeida & Almeida, 1999). Psychological variables Optimism was examined by the three-item optimism subscale in the Life Orientation Test (LOT-R; Scheier, Carver, & Bridges, 1994). Participants rated the items using a 5-point scale (0 = disagree, 4 = completely agree). The alpha coefficient was 0.71. Depressive thoughts were measured with a single item from the Big-Five questionnaire, “Do you feel sad or depressed” (John & Srivastava, 1999). Responses were provided on a 4-point scale (1 = completely disagree, 4 = completely agree). Rating the importance of factors that affect NtD estimation At the end of the questionnaire, participants were asked to rate how important was each of the 13 randomly arranged, preselected factors to their evaluation of their own NtD on a 5-point scale (1 = not important at all, 5 = very important). This evaluation was conducted at the end of the session in order to prevent possible influence on the questionnaire itself, and to help participants reflect upon the factors that they consider important when evaluating their SNtD. Results Most participants (265, 97.4%) rated their SNtD. One-hundred and twenty-six participants (47.5%) reported that they did not feel close to their death at all, 47 (17.7%) felt rather far from death, 48 (18.1%) felt close to death to a moderate degree, 31 (11.7%) felt quite close to death, and only 13 (4.9%) felt very close to death. Participants ranked physical functioning and energy as the most important factors in evaluating SNtD, and gender and parents’ age at death as the least important factors (see Table 1). The means of these ratings were used to rank order the 13 factors, so that items that participants rated as most important received the highest ranking. Table 1. Descriptive Statistics and Ranking of Factors’ Importance Ratings and Correlations between Corresponding Variables and SNtD Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Note: Maximum N = 272. ADL = Activities of daily living; IADL = instrumental ADL; SNtD = Subjective Nearness to Death; n.s.= not significant. *p < .05, **p < .01, ***p < .001. View Large Table 1. Descriptive Statistics and Ranking of Factors’ Importance Ratings and Correlations between Corresponding Variables and SNtD Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Factors’ Importance Ratings (When rating your own NtD how important is…) Mean (SD) Rank Corresponding variable Correlation with SNtD Rank Your general level of physical activity 4.24 (0.96) 1 ADL + IADL .187** 3 Your typical level of energy 4.24 (1.04) 2 Level of energy .276*** 2 Your optimism 4.19 (1.02) 3 Optimism score -.325*** 1 Your ability to concentrate or remember things 4.17 (1.06) 4 Self-rated memory .183** 4 Your living arrangements 4.17 (1.14) 5 Marital status (Dichotomous) -.028 n.s. 11 Your age 3.21 (1.40) 6 Age .133* 6 How sad or depressed you are 3.11 (1.41) 7 Feeling sad or depressed .154* 5 Your financial difficulties 3.07 (1.45) 8 Financial condition .052 n.s. 10 Your education level 3.02 (1.60) 9 Years of education -.101 8 Any recent flare-up, worsening, or onset of a chronic disease 2.81 (1.43) 10 Number of chronic diseases .125* 7 The age of your mother when she died 2.63 (1.52) 11 Age mother died -.081 n.s. 9 Your gender 2.46 (1.60) 12 Gender -.015 n.s. 13 The age of your father when he died 2.45 (1.48) 13 Age father died .021 n.s. 12 Note: Maximum N = 272. ADL = Activities of daily living; IADL = instrumental ADL; SNtD = Subjective Nearness to Death; n.s.= not significant. *p < .05, **p < .01, ***p < .001. View Large Next, we computed the correlation between each corresponding variable and SNtD ratings, and then rank-ordered these correlations according to r level. This analysis showed that the correlations of optimism and energy with SNtD were highest, and the correlations of gender and father’s age at death with SNtD were lowest. The two sets of ranks (the rank of factor importance ratings and the rank of correlations of corresponding variables) were strongly and positively associated with each other (Spearman’s Rho [ρ] = .81, p < .01). A further analysis that included only the seven corresponding variables that were significantly associated with SNtD yielded similar results (ρ = .82, p < .05). Evaluating the rank of categories by averaging the ranks of relevant factors showed that the physical functioning category was ranked the most important, followed by the psychological, health condition, and socioeconomic categories, whereas the genetic category was ranked as the least important. Discussion In line with our first hypothesis, our findings show a strong association between ranking of importance ratings and ranking of correlations between corresponding variables and SNtD, as found before for self-rated health (Benyamini et al., 1999, 2003). These results support the assumption that factors that individuals consider important when thinking of the time left for them to live are indeed similar to the corresponding variables that correlate with SNtD. Thus, individuals may have an internal mental model (Mulcahy & Call, 2006) that helps them estimate the time left to live, and may arrange their current and future life in accordance with this estimate (Carstensen, 2006; Griffin et al., 2013; Hesketh et al., 2011). In line with our second hypothesis, individuals considered the physical functioning and psychological categories as the most important factors in determining their SNtD evaluation. We hypothesized that socioeconomic factors (i.e., education, financial status, and marital status) would be considered the least important, and these factors were indeed rated as lower in importance than others. However, some genetic factors (i.e., gender and parental longevity) were considered the least important. Although it is easy to understand why physical activity was interpreted as important to the time left to live, it is not obvious why genetic factors were considered less important to this evaluation. This surprising finding needs further investigation in order to better understand the mechanism that underlies these evaluations. Moreover, there were several specific factors that individuals rated as important for their SNtD estimations, for which only low correlations were found between the associated corresponding variables and SNtD. For example, marital status was considered important when rating SNtD but it was poorly associated with SNtD. Furthermore, there were some factors that were placed similarly in both rankings but that did not reflect their real effect on age of death, as reported in earlier studies. That is, several health and genetic factors, such as mother’s age at death or the presence of a chronic disease, were ranked low in both ratings, although research suggests that they are important predictors of age at death (Rantanen et al., 2012). One possible explanation is that many of our participants lost their parents at a young age due to the Holocaust and therefore were not looking at parents’ age at death as reflecting their potential longevity. Even when we examined participants who were still younger than their parents’ age at death, parental longevity was not an important predictor of SNtD. Another possible explanation is that people are more influenced by their immediate status (physical functioning and energy) than by remote factors such as parental longevity. We calculated the correlation between parental age at death and SNtD separately for those who are now older than their parents were when they died and for those who are now younger than their parents were when they died. The correlations were low and nonsignificant for both groups (r = .09 and .01 for those who are now younger and for those who are now older than their father was when he died, respectively; r = −.06 and .13 for those who are now younger and for those who are now older than their mother was when she died, respectively). When examining importance ratings for parental age at death, it was 2.93 (SD = 1.47) and 2.24 (SD = 1.45) for those who are now younger and for those who are now older than their father was when he died, respectively (t[233] = 3.41, p < .01), and 3.04 (SD = 1.49) and 2.27 (SD = 1.47) for those who are now younger and for those who are now older than their mother was when she died, respectively (t[237] = 4.02, p < .001). Although importance ratings significantly differed between the two groups, they were lower (between 2.24 and 3.04) than were importance ratings of most other factors. On the other hand, psychological factors were ranked high in both ratings, although they are known to have only low-to-moderate effect in predicting age at death, especially in old-old age (e.g., Ben-Ezra & Shmotkin, 2006; Maier & Smith, 1999). Therefore, in general, older adults have a rather accurate awareness of the factors that correlate with their perception of the time left to live, yet these perceptions might be biased in some cases. Future longitudinal studies that will take actual longevity into consideration could shed light on these discrepancies. Our study has some limitations. First, a more comprehensive list of factors could have changed the importance attributed to each of them. Yet, our results resemble previous findings reported by Benyamini et al. (1999, 2003) regarding self-rated health, suggesting that the number of factors was sufficient in revealing participants’ implicit knowledge. In addition, it is possible that the order of questions (e.g., asking about importance immediately after evaluating each factor) might have affected the correlations. Second, we did not evaluate time to death in years, and future studies would have to assess this issue as well. In sum, this study is the first to examine the factors that individuals consider when estimating how much time they have to live. Our findings show that although individuals are generally aware of the factors that affect nearness to death, they are biased with regards to specific factors. These results may help practitioners who work with older adults in guiding their clients toward the formulation of informed decisions. Funding This work was supported by the Israel Science Foundation (ISF; grant number 1234/14). Conflict of Interest None reported. References Almeida , O. P. , & Almeida , S. A . ( 1999 ). 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The Journals of Gerontology Series B: Psychological Sciences and Social SciencesOxford University Press

Published: Apr 24, 2018

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