Sociodemographic Effects on Task- specific ADL Functioning at the Oldest-old Ages Danan Gu 1 and Qin Xu 2 1. Public Policy, Duke University, China Research Center on Aging

Outline Introduction & objectives Data and methodology Results Discussion

I. Introduction & objectives- Introduction ADL has a hierarchy: Previous research has suggested that Individual loses functioning of each six task probably has ordering in that each task involves different required capability to perform (e.g., Dunlop et al. 1997;Jagger et al. 2001; Katz et al. 1963) Studies systematically examining the dynamic of task-specific ADL and its associates are very rare. None of previous studies, which focus on ADL task-specific, explore the correlations with socio-demographic factors. There is no study to examine the dynamics of each ADL task-specific focusing on the oldest-old in developing countries. One of major limitations is the underestimation of disability in the study of ADL functioning at the old ages (Gill et al. 2002; Zeng, Gu, and Land 2004) The conventional method which does not include the ADL change before dying overestimate effect of age, gender, ethnicity, and living alone on disability transitions while underestimates the effects of SES (Gu & Zeng 2004).

I. Introduction & objective- Objective By including the ADL information before dying, this study tries to capture more robust effects of sociodemographic factors on task-specific ADL functioning over a two-year survey interval.

- II. Data source & methodology - Data source The Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 1998, 2000, and All three waves of data are pooled together. Persons who reported age 106 or higher at Time 1 are excluded from this study. Total : 19,778 Male: 8,142 Female: 11,636

II. Data source & methodology II. Data source & methodology - methodology Time 1 : the start-point of each two-year interval. Time 2 :the endpoint of each two-year interval.

Measuring onset and recovery of disability in each ADL task ADL Bathing Toileting Dressing Indoor transferring Eating Continence

II. Data source & methodology -continue each ADL task not disabled(or no need help) disabled (or need help)

the information of ADL changes before dying onset of task disability task recovery

An individual is considered having an “onset” of disability in one task if he/she moved from not disabled (no need in help) in that task at Time 1 to disabled (need in help) in the same task at Time 2 or before dying A person is classified as having a “recovery” from disability in one task if he/she moved from need in help in that task at Time 1 to no need in help in the same task at Time 2 or before dying

six items into two categories requires both upper and low extremities (high-level tasks/items ) include bathing, toileting, dressing, indoor transferring requires upper extremities only or continence (low-level tasks/items ) include feeding, continence Factor analysis confirms this classification

Sociodemographic factors Age: 80-89, 90-99, Sex: Male, Female Residence: urban, rural Ethnic group: Han, other minorities Education: 0 year (illiteracy), 1 + years of schooling Economic independence: economic independence: mainly relying on pension or own financial source economic dependence: namely relying on other resources such as spouse, children or other family members, or government subsidy and others

Sociodemographic factors -continue Primary lifetime occupation for males: agriculture, non-agriculture for females: agriculture, housewife, non- agriculture Marital status currently not married (never married, divorced, and widowed) currently married Living arrangement :living alone, not living alone

Control variables The confounders include: (1) Family/social support and connection: Religious activities, proximity with children, playing card, and who take care of the elder in the daily life are considered as the proxy of family and social supports/connections in this study. (2) Health practice: alcoholic consumption, smoking, diet, and doing exercise (3) Health conditions: cognitive function, self-reported health, chronic disease conditions, hearing and visual function, and functional limitations. (4) The length of surviving between Time 1 and Time 2, and whether the respondent died or not before Time 2 were also included in the model to adjust their influence.

Statistical models models for males and females separately those who lost to follow-up respondents at Time 2 are excluded Random effect logit model after correcting intra- person correlation was applied

III. Results

Table 1 Percentage distributions of socio- demographic variables by gender (%) MalesFemales Total Age Age Age Rural Han group Years of schooling Primary occupation :Agriculture Primary occupation :Housekeeper NA32.07 Primary occupation :Non-agriculture Economic independence Not Living alone Currently with spouse

Table 2 Dynamics changes of each ADL task by gender MalesFemales Onset of disability in bathing toileting dressing indoor transferring eating continence Recovery from disability in bathing toileting dressing indoor transferring eating continence

The functioning of the high level tasks declines faster than the low level tasks. The incidence rate for bathing is almost two times more than that of continence. The recovery rates present an opposite pattern, and the recovery rate for bathing is 50% less than that of continence.

BathingToiletingDressingTransferringEatingContinence Onset Age Females (Males) Single age 1.064***1.070***1.066***1.060***1.042**1.034* N (6149)(6793)(6845)(6890)(6984)(6951) Age Females (Males) 1.337**1.352**1.334**1.520***1.243*1.213# Single age 1.043**1.032**1.042***1.032**1.034**1.014 N (3962)(4849)(4978)(5052)(5276)(5422) Age Females (Males) * #1.374*1.120 Single age N(1933)(2606)(2748)(2815)(3086)(3428) Recovery Age Females (Males) # Single age 0.932** # N (1120)(504)(451)(398)(310)(344) Age Females (Males) 0.524***0.698*0.640*0.602*0.516**0.880 Single age ***0.945*0.949*0.904**0.985 N (1986)(1124)(997)(916)(695)(547) Age Females (Males) 0.568** **0.636* Single age N (2089)(1424)(1285)(1211)(942)(595) Notes: (1) Male is the reference group. Age is measured at the beginning of each two-year interval. (2) N is the number of observations. (3) The results are based on controlling other confounders mentioned in the text. (4) Odds ratios and their significant level were corrected by intra-subject correlations due to some subjects contributing two or threemore than one observations to the pooled data set at a specific time (Time 1or Time 2). (5) #, p<0.1; *, p<0.05; **, p<0.01; ***, p< Table 3 Odds ratios of gender and age on the onset of disability and recovery from disability of each ADL task

Gender differential effect is significant among nonagenarians and centenarians, and it reaches the biggest among nonagenarians. The gender differential patterns are similar across six tasks. The effect of increasing each additional age on onset of and recovery from task-specific disability is different both across tasks and across age groups. The effect of increasing each additional age on onset of task disability is gradually diminishing with the advancement of age.

BathingToiletingDressingTransferringEatingContinence Males Age (80-89) 1.442***1.219*1.194*1.142# Age (80-89) 1.672***1.296* Urban (rural) Minorities (Han) 0.530***0.744*0.693**0.645** ** 1+ year (s) schoolings (no schooling) 0.840* Non-agriculture (agriculture) Economic independence (dependence) *1.042 Living alone (not living alone) 0.643***0.757*0.763*0.679**0.798#0.750* Currently married (not married) Chronic conditions (no) 1.183*1.228**1.200*1.133#1.287**1.098 Physical function limited (no) 1.180*1.174*1.368***1.179*1.194*1.179* No need help in bathing at Time 1 (no) ***0.554***0.649***0.666***0.636*** No need help in toileting at Time 1 (no) #0.587*0.701#0.648* No need help in dressing at Time 1 (no) 0.547# No need help in transferring at Time 1 (no) * No need help in eating at Time 1 (no) No need help in continence at Time 1 (no) 0.606** Log Likelihood ***5398.7***5401.4***5155.1***5033.4***4919.9*** Df32 Nagelkerke R Number of observations Table 4 Odds ratios of the onset of disability of each ADL task

BathingToiletingDressingTransferringEatingContinence Females Age (80-89) 1.648***1.601***1.638***1.562***1.434***1.306** Age (80-89) 2.036***1.895***1.717***1.606***1.601***1.228* Urban (rural) 1.221**1.234** **1.139*1.185** Minorities (Han) 0.661***0.732**0.803*0.728** * 1+ year (s) schoolings (no schooling) Housewife (agriculture) 1.234** Non-agriculture (agriculture) *0.863 Economic independence (dependence) Living alone (not living alone) 0.850* Currently married (not married) Chronic conditions (no) ** *1.086 Physical function limited (no) 1.187**1.218**1.253***1.221** * No need help in bathing at Time 1 (no) ***0.689***0.634***0.822**0.825* No need help in toileting at Time 1 (no) 0.572** No need help in dressing at Time 1 (no) 0.647#0.700* **0.680**0.713** No need help in transferring at Time 1 (no) #0.744* No need help in eating at Time 1 (no) # No need help in continence at Time 1 (no) *0.735* Log Likelihood ***7980.0***8144.1***7975.8***8018.9***7946.4*** Df33 Nagelkerke R Number of observations Notes: (1) Reference group of each covariate is listed in the parentheses. (2) All variables are measured at the beginning of each two-year interval. (3) The results are based on controlling other confounders mentioned in the text. (4) Odds ratios and their significant level were corrected by intra-subject correlations due to some subjects contributing two or threemore than one observations to the pooled data set at a specific time (Time 1or Time 2). (5) #, p<0.1; *, p<0.05; **, p<0.01; ***, p<0.001.

BathingToiletingDressingTransferringEatingContinence Males Age (80-89) *1.060 Age (80-89) 0.711# #1.156 Urban (rural) 0.648**0.724# Minorities (Han) year (s) schoolings (no schooling) 0.678** ** Non-agriculture (agriculture) *1.057 Economic independence (dependence) *0.727 Living alone (not living alone) 1.928* # Currently married (not married) 0.770#0.738# Chronic conditions (no) * Physical function limited (no) * No need help in bathing at Time 1 (no) # No need help in toileting at Time 1 (no) 1.454* No need help in dressing at Time 1 (no) No need help in transferring at Time 1 (no) No need help in eating at Time 1 (no) No need help in continence at Time 1 (no) Log Likelihood ***1057.6***1013.3***846.7**629.9***615.1*** Df32 Nagelkerke R Number of observations Table 5 Odds ratios of the recovery of each ADL task

BathingToiletingDressingTransferringEatingContinence Females Age (80-89) 0.807# Age (80-89) 0.748* #0.684* Urban (rural) 0.637***0.838#0.814# # Minorities (Han) 1.603** # year (s) schoolings (no schooling) **0.827 Housewife (agriculture) 0.737** *0.739* Non-agriculture (agriculture) Economic independence (dependence) **0.472#0.980 Living alone (not living alone) 1.496* * Currently married (not married) 1.687* Chronic conditions (no) 0.795* Physical function limited (no) No need help in bathing at Time 1 (no) * * * No need help in toileting at Time 1 (no) ** No need help in dressing at Time 1 (no) 1.311* **0.921 No need help in transferring at Time 1 (no) 1.578***1.749***1.296# No need help in eating at Time 1 (no) 0.744* # No need help in continence at Time 1 (no) 1.442**1.288*1.501**1.457**1.406**--- - Log Likelihood ***2638.5***2352.7***2082.6***1810.1***1252.4*** Df33 Nagelkerke R Number of observations Notes: (1) Reference group of each covariate is listed in the parentheses. (2) All variables are measured at the beginning of each two-year interval. (3) The results are based on controlling other confounders mentioned in the text. (4) Odds ratios and their significant level were corrected by intra-subject correlations due to some subjects contributing two or threemore than one observations to the pooled data set at a specific time (Time 1or Time 2). (5) #, p<0.1; *, p<0.05; **, p<0.01; ***, p<0.001.

Among males, compared to octogenarians, nonagenarians and centenarians have a higher risk to develop task-specific disability in high level of hierarchy, while they share a similar risk to develop task disability in the low level tasks in the hierarchy. On the other hand, female nonagenarians and centenarians have a significant higher risk to develop task-specific disability in all tasks compared to female octogenarians. The disadvantage of older ages in effect on task recovery is less apparent than its effect on onset of task-specific disability (see Table 5). Such results indicate that disability deceleration is more obvious for males than for females at oldest-old ages.

Result presented in Table 4 reveals that urban/rural residential difference in onset of task-specific disability is homogeneous rather heterogeneous although urban oldest olds have a higher chance to have onsets of task-specific disability and lower chance to get recovery on general. The difference of residential effect on task-specific disability between females was found. Whereas urban males have same risks to have onset of task-specific disability as rural males, urban females experience 10-20% higher risks to develop task-specific disability than rural females. Furthermore, Table 5 indicates that urban oldest-olds have a lower chance to get recovery from high level task disability for both males and females.

Table 4 illustrates that Minority ethnicities have better ADL functioning over Han, the majority. Minorities have 20-45% lower risk to develop task-specific disability except eating for both males and females. Table 5 further indicates that although minorities have higher chances to recover once they have onset of disability across all tasks for both males and females, such higher chances are not statistically significant possibly due to highly individual variation.

SES has limited effect on both onset of and recovery from task-specific disability. SES demonstrates the similar pattern across tasks and across genders. Living alone has significant lower risk to develop disability across tasks for males, but such effective is not significant among females (Table 4). On the other hand, the positive effects of living alone on task-specific recovery are not all significant across tasks despite all the odds ratios are much higher than 1 except eating for females (Table 5). The protective effect of marriage on task-specific disability and recovery was not detected.

Additionally, for males, chronic condition and functional limitation will raise the risk of developing disability across tasks. But they don’t have effect on getting recovery from disability across tasks. Generally speaking, persons who are in absence of limitation in high level tasks in the hierarchy will postpone his/her onset of disability of the low tasks in the hierarchy. Such pattern is similar for both males and females (Table 4). The results listed in Table 5 show that it will not help male oldest-olds to get recovery from a task disability if they have no limits in any other task. But for female oldest-olds, they will have a higher chance to get recovery from a task disability if they don’t have functioning limits in other task.

IV. Discussion Slightly higher recovery from each task disability was observed. The main possible reason is that China has a higher mortality, which makes the oldest- old in China more robust compared to their counterparts in western nations. Our results show that each sociodemographic factor has somewhat different role in dynamics of ADL functioning across tasks. Consistency and inconsistency with previous studies. Although the results of this study are far from conclusive and deserve further investigation, they provide new knowledge about the general patterns of dynamics of task-specific disability of the oldest-old, which contributes to a better understanding of the social and demographic factors associated with task-specific onset of and recovery from disability.

One strength point of this study lies its systematically examination of socio-demographic effect on dynamics of six task-specific ADL functions at the oldest-old ages, which is rarely touched by previous studies, but is more informative. One limitation of the present study is that information on ADL status before dying for the dead persons before the second interview is obtained from next-to-kin, which may involve some bias. We only collected one episode of dynamic change for each ADL task both among survivors and among the deceased persons, which will not fully capture the whole story of dynamics of each task given.