Disability Trajectories at the End of Life: A "Countdown" Model

Advancing methods for the biodemography of aging within social contexts

Several social dimensions including social integration, status, early-life adversity, and their interactions across the life course can predict health, reproduction, and mortality in humans. Accordingly, the social environment plays a fundamental role in the emergence of phenotypes driving the evolution of aging. Recent work placing human social gradients on a biological continuum with other species provides a useful evolutionary context for aging questions, but there is still a need for a unified evolutionary framework linking health and aging within social contexts. Here, we summarize current challenges to understand the role of the social environment in human life courses. Next, we review recent advances in comparative biodemography and propose a biodemographic perspective to address socially driven health phenotype distributions and their evolutionary consequences using a nonhuman primate population. This new comparative approach uses evolutionary demography to address the joint dynamics of populations, social dimensions, phenotypes, and life history parameters. The long-term goal is to advance our understanding of the link between individual social environments, population-level outcomes, and the evolution of aging.

Does long-term care insurance reduce the disability among middle-aged and older adults? Evidence from China

This study aimed to examine whether the implementation of Long-Term Care Insurance (LTCI) policy could reduce the disability among middle-aged and older adults in China, and to test the heterogeneity of the effects. Data came from four waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011 to 2018). The Difference-In-Differences (DID) method and the panel data fixed effect model were used to estimate the effect of implementation of LTCI policy on disability among individuals aged 45 years and above. The LTCI policy had a positive impact on reducing disability among middle-aged and older people. Females, younger adults, city dwellers, and individuals living alone benefited the most from LTCI policy. The results provided empirical evidence for the implementation of LTCI policy in China and other similar countries as China. The implementation of LTCI policy should also pay more attention to inequity of the effects on reducing disability among different demographic groups.

Trajectories in physical performance and fall prediction in older adults: A longitudinal population-based study

BACKGROUND

A physical performance evaluation can inform fall risk in older people, however, the predictiveness of a one-time assessment is limited. The trajectory of physical performance over time has not been well characterized and might improve fall prediction. We aimed to characterize trajectories in physical performance and determine if fall prediction improves using trajectories of performance.

METHODS

This was a cohort design using data from the National Health and Aging Trends Study. Physical performance was measured by the short physical performance battery (SPPB) with scores ranging from 0 (worst) to 12 (best). The trajectory of SPPB was categorized using latent class modeling and slope-based multilevel linear regression. We used Cox proportional hazards models with an outcome of time to ≥2 falls from annual self-report to assess predictiveness after adding SPPB trajectories to models of baseline SPPB and established non-physical-performance-based variables.

RESULTS

The sample was 5969 community-dwelling Medicare beneficiaries aged ≥65 years. The median number of annual SPPB evaluations was 4 (IQR, 3-7). Mean baseline SPPB was 9.2 (SD, 3.0). The latent class model defined SPPB trajectories over a range of two to nineteen categories. The mean slope from the slope-based model was -0.01 SPPB points/year (SD, 0.14). Discrimination of the baseline SPPB model to predict time to ≥2 falls was fair (Harrell's C, 0.65) and increased after adding the non-performance-based predictors (Harrell's C, 0.70). Discrimination slightly improved with the SPPB trajectory category variable that had the best fit (Harrell's C, 0.71) but did not improve with the SPPB linear slope. Calibration with and without the trajectory categories was similar.

CONCLUSIONS

We found that the trajectory of physical performance did not meaningfully improve upon fall prediction from a baseline physical performance assessment and established non-performance-based information. These results do not support longitudinal SPPB assessments for fall prediction.

A Model to Compare International Hospital Bed Numbers, including a Case Study on the Role of Indigenous People on Acute 'Occupied' Bed Demand in Australian States

Comparing international or regional hospital bed numbers is not an easy matter, and a pragmatic method has been proposed that plots the number of beds per 1000 deaths versus the log of deaths per 1000 population. This method relies on the fact that 55% of a person's lifetime hospital bed utilization occurs in the last year of life-irrespective of the age at death. This is called the nearness to death effect. The slope and intercept of the logarithmic relationship between the two are highly correlated. This study demonstrates how lines of equivalent bed provision can be constructed based on the value of the intercept. Sweden looks to be the most bed-efficient country due to long-term investment in integrated care. The potential limitations of the method are illustrated using data from English Clinical Commissioning Groups. The main limitation is that maternity, paediatric, and mental health care do not conform to the nearness to death effect, and hence, the method mainly applies to adult acute care, especially medical and critical care bed numbers. It is also suggested that sensible comparison can only be made by comparing levels of occupied beds rather than available beds. Occupied beds measure the expressed bed demand (although often constrained by access to care issues), while available beds measure supply. The issue of bed supply is made complex by the role of hospital size on the average occupancy margin. Smaller hospitals are forced to operate at a lower average occupancy; hence, countries with many smaller hospitals such as Germany and the USA appear to have very high numbers of available beds. The so-called 85% occupancy rule is an "urban myth" and has no fundamental basis whatsoever. The very high number of "hospital" beds in Japan is simply an artefact arising from "nursing home" beds being counted as a "hospital" bed in this country. Finally, the new method is applied to the expressed demand for occupied acute beds in Australian states. Using data specific to acute care, i.e., excluding mental health and maternity, a long-standing deficit of beds was identified in Tasmania, while an unusually high level of occupied beds in the Northern Territory (NT) was revealed. The high level of demand for beds in the NT appears due to an exceptionally large population of indigenous people in this state, who are recognized to have elevated health care needs relative to non-indigenous Australians. In this respect, indigenous Australians use 3.5 times more occupied bed days per 1000 deaths (1509 versus 429 beds per 1000 deaths) and 6 times more occupied bed days per 1000 population (90 versus 15 beds per 1000 population) than their non-indigenous counterparts. The figure of 1509 beds per 1000 deaths (or 4.13 occupied beds per 1000 deaths) for indigenous Australians is indicative of a high level of "acute" nursing care in the last months of life, probably because nursing home care is not readily available due to remoteness. A lack of acute beds in the NT then results in an extremely high average bed occupancy rate with contingent efficiency and delayed access implications.

Trajectories of Pain in Very Old Age: The Role of Eudaimonic Wellbeing and Personality

Pain is common in very old age and in the last years prior to death. However, little is known regarding longitudinal trajectories of pain in very old age and at the end of life. Moreover, whereas medical and morbidity-related factors contributing to pain are established, the role of psychosocial factors, such as eudaimonic wellbeing or personality as potential determinants of late-life pain trajectories has so far not been sufficiently investigated. We used data from the LateLine project. The sample consisted of n = 118 very old adults (M = 90.5 years, SD = 2.8 years) who were living alone at baseline and who had died between 2009 and 2021. They took part in up to 16 measurement occasions (M = 5.2, SD = 4.7, range 1–16) within an observational interval of 7 years. Assessment of pain was based on the SF-36 bodily pain subscale. Key indicators of eudaimonic wellbeing (autonomy, environmental mastery, and purpose in life) as well two of the Big Five personality traits (neuroticism and extraversion) were included as predictors. We controlled in all analyses for gender, education, subjective health, and depressive symptoms. Contrasting pain trajectories over chronological age (time since birth) vs. time to death, a time-to-death-related model resulted in a better model fit and accounted for a larger amount of pain variability than the age-related model. Mean-level change in pain, both over age and time to death, was not significant, but there was substantial interindividual variability in intraindividual trajectories. Age-related change in pain was significantly predicted by autonomy and neuroticism, with increasing pain among those who had lower initial autonomy scores and higher initial neuroticism scores. With regard to time-to-death-related trajectories of pain, higher purpose in life as well as lower extraversion at baseline predicted less increase or even steeper decrease in pain with approaching death. Our findings suggest that, despite overall mean-level stability in pain both over age and time to death, there is a substantial proportion of individuals who reveal deterioration in pain over time. Regarding the role of psychosocial predictors, personality traits and eudaimonic wellbeing are related with late-life pain trajectories both over age and time-to-death.

Incident Care Trajectories for Older Adults with and without Dementia

OBJECTIVE

Despite cross-sectional evidence that persons living with dementia receive disproportionate hours of care, studies of how care intensity progresses over time and differs for those living with and without dementia have been lacking.

METHODS

We used the 2011-2018 National Health and Aging Trends Study to estimate growth mixture models to identify incident care hour trajectories ("classes") among older adults (N=1,780).

RESULTS

We identified four incident care hour classes: "Low, stable," "High, increasing," "24/7 then high, stable," and "Low then resolved." The high-intensity classes had the highest proportions of care recipients with dementia and accounted for nearly half of that group. Older adults with dementia were 3-4 times as likely as other older adults to experience one of the two high-intensity trajectories. A substantial proportion of the 4 in 10 older adults with dementia who were predicted to be in the "Low, stable" class lived in residential care settings.

DISCUSSION

Information on how family caregiving is likely to evolve over time in terms of care hours may help older adults with and without dementia, the family members, friends, and paid individuals who care for them, as well as their health care providers assess and plan for future care needs.

Joint trajectories of disability and related factors among older adults in China

OBJECTIVES

This study aimed to identify disability trajectories and discover early disablement process factors associated with disability trajectories among older adults in China.

STUDY DESIGN

This is a prospective cohort study.

METHODS

Data were obtained from five waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 2005 to 2018). The multitrajectory modelling approach was used to estimate the joint trajectories of activity of daily living (ADL) disability and instrumental activity of daily living (IADL) disability. A multinomial regression model was used to investigate how baseline disablement process factors among individuals aged 65-95 years are related to joint disability trajectory groups.

RESULTS

We identified three typical joint ADL and IADL disability trajectories. Demographic characters, social participation, community services, disease, impairment and functional limitations can all impact the disability trajectories among older adults.

CONCLUSIONS

The joint ADL and IADL disability trajectories of older adults are increasing, and the Chinese government should pay more attention to disability process elements to improve disability interventions among older adults.

One-Year Changes in Activities of Daily Living, Usability, Falls and Concerns about Falling, and Self-Rated Health for Different Housing Adaptation Client Profiles

The purpose of this study was to investigate one-year changes and differences in changes in activities of daily living (ADL), usability, a history of falls, concerns about falling, and self-rated health across five housing adaptation (HA) client profiles identified previously using a cluster analysis approach: older adults with low level of disability (n = 59); older adults with medium/high level of disability (n = 26); adults with low level of disability (n = 10); adults with high level of disability (n = 8); and older adults with medium level of disability including at least moderate cognitive impairment (n = 5). Comparisons between the five profiles include secondary analyses aggregating those with low level of disability and those with medium/high level of disability. Changes within the client profiles demonstrate a complex pattern of improvements and declines, depending on outcome, with no profile showing consistent improvement or decline across all outcomes. The risks of deterioration over one year were the highest among those with cognitive impairments at baseline, but no recommendation of prioritization decisions based on baseline profiles can be made. Instead, it seems that all HA clients, independently of baseline profile, are at risk of increasing disability over time and require follow-up evaluations regularly.

Trajectories of Suffering in the Last Year of Life Among Patients With a Solid Metastatic Cancer

BACKGROUND

Reducing suffering at the end of life is important. Doing so requires a comprehensive understanding of the course of suffering for patients with cancer during their last year of life. This study describes trajectories of psychological, spiritual, physical, and functional suffering in the last year of life among patients with a solid metastatic cancer.

PATIENTS AND METHODS

We conducted a prospective cohort study of 600 patients with a solid metastatic cancer between July 2016 and December 2019 in Singapore. We assessed patients' psychological, spiritual, physical, and functional suffering every 3 months until death. Data from the last year of life of 345 decedents were analyzed. We used group-based multitrajectory modeling to delineate trajectories of suffering during the last year of a patient's life.

RESULTS

We identified 5 trajectories representing suffering: (1) persistently low (47% of the sample); (2) slowly increasing (14%); (3) predominantly spiritual (21%); (4) rapidly increasing (12%); and (5) persistently high (6%). Compared with patients with primary or less education, those with secondary (high school) (odds ratio [OR], 3.49; 95% CI, 1.05-11.59) education were more likely to have rapidly increasing versus persistently low suffering. In multivariable models adjusting for potential confounders, compared with patients with persistently low suffering, those with rapidly increasing suffering had more hospital admissions (β=0.24; 95% CI, 0.00-0.47) and hospital days (β=0.40; 95% CI, 0.04-0.75) during the last year of life. Those with persistently high suffering had more hospital days (β=0.70; 95% CI, 0.23-1.17).

CONCLUSIONS

The course of suffering during the last year of life among patients with cancer is variable and related to patients' hospitalizations. Understanding this variation can facilitate clinical decisions to minimize suffering and reduce healthcare costs at the end of life.

A Longitudinal Study of Cognitive and Instrumental Activities of Daily Living Disablement Among the Oldest Mexican Americans

ObjectivesMexican Americans live longer on average than other ethnic groups, but often with protracted cognitive and physical disability. Little is known, however, about the role of cognitive decline for transitions in instrumental activities of daily living (IADL) disability and tertiary outcomes of the IADL disablement for the oldest old (after 80 years old). Methods We employ the Hispanic Established Populations for the Epidemiologic Study of the Elderly (2010-2011, 2012-2013, and 2016, N = 1,078) to investigate the longitudinal patterns of IADL decline using latent transition analysis. Results Three IADL groups were identified: independent (developing mobility limitations), emerging dependence (limited mobility and community activities), and dependent (limited mobility and household and community activities). Declines in cognitive function were a consistent predictor of greater IADL disablement, and loneliness was a particularly salient distal outcome for emerging dependence. Discussion These results highlight the social consequences of cognitive decline and dependency as well as underscore important areas of intervention at each stage of the disablement process.

Extending the analysis of functional ability trajectories to unexplored national contexts: The case of Chile

OBJECTIVES

Despite the enormous advances in the field, most evidence about functional ability trajectories in old age comes from studies conducted in developed and high-income countries. This research aims to build on these previous advances to examine functional ability trajectories in Chile.

METHODS

Drawing on a robust, publicly available 15-years panel dataset (2004-2018), and using sequence analysis, we examine functional ability trajectories types among four age groups (people aged 46-50, 51-55, 56-60, and 61-64 at baseline). Then, we analyze trajectories' dynamics looking at intra-individual health-declining and health-recovery transitions between functional ability statuses, within each trajectory type. Finally, we assess how multiple baseline individual characteristics predict the likelihood of following a functional ability trajectory type, using multinomial regression models.

RESULTS

Across all age groups, an important fraction (between 26%-50%) reports stable healthy trajectories, and between 10%-20% follow equivocal-declining trajectories (i.e., exhibiting both health-declining and health-recovery intra-individual transitions), suggesting that age might not be the main source of heterogeneity in functional ability trajectories. Overall, women, lower educated people, nonworking individuals, and people with a higher burden of chronic conditions at baseline, are more prevalent among health-declining trajectory types; however, these results are not constant across the age groups analyzed.

DISCUSSION

This nationally focused study reinforces the feasibility and usefulness of an in-depth analysis of functional ability trajectories in old age. The study findings can be crucial to define different prevention strategies according to the functional ability path that an individual might follow, especially in countries like Chile that currently navigates the challenges of population aging.

Cumulative Inequality at the End of Life?: Racial Disparities in Impairment in the Time Before Death

OBJECTIVES

Drawing from cumulative inequality (CI) theory, the current study examined racial disparities in impairment as individuals approached death to determine whether proposed mechanisms hypothesized to fuel or diminish racial disparities at late ages were at work at the end of individualized life spans.

METHOD

Black-white disparities were analyzed among decedents using latent growth curves based on the data from the North Carolina Established Populations for Epidemiologic Studies of the Elderly (EPESE) (N = 1,926).

RESULTS

Consistent with previous literature, racial inequalities in functional disparities diminish at late ages. However, significant black-white disparities emerge as older adults approach death, exponentially increasing within the 2 years immediately preceding death. Further, these disparities are not fully mediated by socioeconomic status.

DISCUSSION

The results confirm that CI in health outcomes is observable in late life among individual life spans, suggesting the years surrounding death may be a particularly vulnerable period for health inequality. Future research should examine how advantaged statuses translate to increased access to health-related resources that aid in maintaining greater functional independence until the last stage of life.

Cross-Cultural Measurement Invariance of a Measure of Disability for White, Black, Hispanic and Asian Older Adults

INTRODUCTION

This study aims to determine the cross-cultural measurement equivalence of the Washington Group General Measure of Disability for older adults.

MATERIALS AND METHODS

This study used the 2012 California Health Interview Survey. The sample included 14,115 non-Hispanic White, Black, Hispanic and Asian adults aged 65 and older. Analysis was conducted using multi-group confirmatory factor analysis (CFA), parallel and Tau-equivalent tests.

RESULTS

The results indicated that the measure was valid for use with older adults (Satorra Bentler χ2 = 13.27, df = 3, p = 0.005, GFI = 0.996). Multi-group CFA indicated comparisons were valid between Whites with Blacks, and Hispanics with Asians. Cognitive disability was associated with independent living disability for Whites and Blacks, and with sensory disability for Hispanics and Asians.

CONCLUSIONS

Findings indicated the measure is valid for cross-cultural comparison for certain racial/ethnic groups. Further research is needed to understand differences in associations of cognitive decline with other areas of disability for older adults.

Functioning profiles in a nationally representative cohort of Spanish older adults: A latent class study

Ageing well involves individuals continuing participating in personal, social and civic affairs even in older age. From this standpoint, limitations in individual's functioning (beyond the mere absence of disease) may drastically impact on how well people becoming older. This study aimed to identify functional status profiles in a nationally representative sample of older adults, using latent class analysis methods. Moreover, it intended to study the how identified classes would be related to health-related outcomes later in life, as a way to provide some evidence on predictive validity. Data from a nationally representative sample of Spanish older adults (N = 2,118; 56.18% women; M = 71.50 years, SD = 7.76), were used. Profiles were identified according to a large set of functioning indicators from multiple domains using latent class analysis. Outcomes were studied over a 3-year follow-up, considering both the individual (quality of life, well-being and mortality) and institutional level (health service utilisation). As a result, seven profiles were identified: normative profile (showed by most participants), limited cognitive functioning class, limited global functioning class, limited mental and mobility functioning class, poor self-reported health class, limited sensory functioning class and limited objective functioning class. All the profiles with limitations across domains showed poor outcomes. Multidimensional limitations were related to the worst outcomes, especially when psychosomatic complaints and high feelings of loneliness were reported. To sum up, latent class analysis constitutes a suitable alternative to study population heterogeneity, providing relevant evidence to help making decision in public and community health.

Aging With Disability: Populations, Programs, and the New Paradigm An Introduction to the Special Issue

Objective: The purpose of this article is to introduce a special issue dedicated to research at the intersection of aging and disability. Method: We provide some context for the importance of cross-disciplinary collaboration among aging and disability researchers and summarize the nine articles in this issue. Results: Articles in the special issue are centered around several overarching themes. These include meaningful social and community participation, goals and values in the context of disability, and the reach and effectiveness of programs and policies on rehabilitation and service utilization. Conclusion: As care models continue to merge aging and disability services, collaboration among traditional aging and disability research networks can lead to improved outcomes for adults aging with long-term disability.

Multisystem Trajectories Over the Adult Life Course and Relations to Cardiovascular Disease and Death

BACKGROUND

Comprehensive conjoint characterization of long-term trajectories representing several biological systems is lacking.

METHODS

We measured serially indicators representing 14 distinct biological systems in up to 3,453 participants attending four Framingham Study examinations: bone mineral density, body mass index (BMI), C-reactive protein, glomerular filtration rate, forced vital capacity (FVC), 1 second forced expiratory volume/FVC ratio (FEV1/FVC), gait speed, grip strength, glycosylated hemoglobin (HbA1c), heart rate, left ventricular mass, Mini-Mental State Examination (MMSE), pulse pressure, and total/high-density lipoprotein cholesterol ratio (TC/HDL).

RESULTS

We observed that correlations among the 14 sex-specific trajectories were modest (r < .30 for 169 of 182 sex-specific correlations). During follow-up (median 8 years), 232 individuals experienced a cardiovascular disease (CVD) event and 393 participants died. In multivariable regression models, CVD incidence was positively related to trajectories of BMI, HbA1c, TC/HDL, gait time, and pulse pressure (p < .06); mortality risk was related directly to trajectories of gait time, C-reactive protein, heart rate, and pulse pressure but inversely to MMSE and FEV1/FVC (p < .006). A unit increase in the trajectory risk score was associated with a 2.80-fold risk of CVD (95% confidence interval [CI], 2.04-3.84; p < .001) and a 2.71-fold risk of death (95% CI, 2.30-3.20; p < .001). Trajectory risk scores were suggestive of a greater increase in model c-statistic compared with single occasion measures (delta-c compared with age- and sex-adjusted models: .032 vs .026 for CVD; .042 vs .030 for mortality).

CONCLUSIONS

Biological systems age differentially over the life course. Longitudinal data on a parsimonious set of biomarkers reflecting key biological systems may facilitate identification of high-risk individuals.

Long-Term Care Use During the Last 2 Years of Life in Sweden: Implications for Policy to Address Increased Population Aging

OBJECTIVES

To map out the total use of long-term care (LTC; ie, home care or institutional care) during the last 2 years of life and to investigate to what extent gender differences in LTC use were explained by cohabitation status and age at death.

DESIGN

The National Cause of Death Register was used to identify decedents. Use of LTC was based on the Social Services Register (SSR) and sociodemographic factors were provided by Statistics Sweden.

SETTING AND PARTICIPANTS

All persons living in Sweden who died in November 2015 aged ≥67 years (n = 5948).

METHODS

Zero inflated negative binomial regression was used to estimate the relative impact of age, gender, and cohabitation status on the use of LTC.

RESULTS

Women used LTC to a larger extent [odds ratio (OR) 2.17, 95% confidence interval (CI) 1.92-2.50] and for a longer period [risk ratio (RR) 1.14, 95% CI 1.11-1.18] than men. When controlling for age at death and cohabitation status, gender differences in LTC attenuated (OR 1.47, 95% CI 1.28-1.72) and vanished in regard to the duration. In the controlled model, women used LTC for 15.6 months (95% CI 15.2-16.0) and men for 14.1 months (95% CI 13.7-14.5) out of 24 months. The length of stay in institutional care was 7.2 (95% CI 6.8-7.5) and 6.2 months (95% CI 5.8-6.6), respectively.

CONCLUSIONS AND IMPLICATIONS

A substantial part of women's greater use of LTC was due to their higher age at death and because they more often lived alone. Given that survival continues to increase, the association between older age at death and LTC use suggests that policy makers will have to deal with an increased pressure on the LTC sector. Yet, increased survival among men could imply that more women will have access to spousal caregivers, although very old couples may have limited capacity for extensive caregiving at the end of life.

Trajectories of Work Disability and Economic Insecurity Approaching Retirement

OBJECTIVES

In this article, we examine the connection between trajectories of work disability and economic precarity in late midlife. We conceptualize work disability as a possible mechanism linking early and later life economic disadvantage.

METHODS

We model trajectories of work disability characterized by timing and stability for a cohort of Baby Boomers (22-32 in 1981) using 32 years of data from the Panel Study of Income Dynamics and latent class analysis. Measures of childhood disadvantage are included as predictors of work disability trajectories, which are subsequently included in logistic regression models predicting four economic outcomes (poverty, asset poverty, home ownership, and pension ownership) at ages 54-64.

RESULTS

Childhood disadvantage selected individuals into five distinct classes of work disability that differed in timing and stability. All of the disability trajectories were associated with an increased risk of economic insecurity in late midlife compared to the never work disabled.

DISCUSSION

This study contributes to the aging literature through its incorporation of the early life origins of pathways of disability and their links to economic outcomes approaching retirement. Findings suggest work disability is anchored in early life disadvantage and is associated with economic insecurity later in life.

Robust Respondents and Lost Limitations: The Implications of Nonrandom Missingness for the Estimation of Health Trajectories

OBJECTIVE

We offer a strategy for quantifying the impact of mortality and attrition on inferences from later-life health trajectory models.

METHOD

Using latent class growth analysis (LCGA), we identify functional limitation trajectory classes in the Health and Retirement Study. We compare results from complete case and full information maximum likelihood (FIML) analyses, and demonstrate a method for producing upper- and lower-bound estimates of the impact of attrition on results.

RESULTS

LCGA inferences vary substantially depending on the handling of missing data. For older adults who die during the follow-up period, the widely used FIML approach may underestimate functional limitations by up to 20%.

DISCUSSION

The most commonly used approaches to handling missing data likely underestimate the extent of poor health in aging populations. Although there is no single solution for nonrandom missingness, we show that bounding estimates can help analysts to better characterize patterns of health in later life.

Disability pathways preceding death in England by socio-economic status

The role of socio-economic status (SES) in the last years of life is an under-researched aspect of health inequalities. This study examines disability patterns preceding death using data from the English Longitudinal Study of Ageing. We use repeated measures latent class analysis to identify the most common pathways preceding death in terms of walking ability and limitations in activities of daily living. Three pathways emerge: one characterized by consistently low disability; a second by a constant high level of functional limitations; and a third by medium impairment. We examine how different SES indicators predict belonging to each disability pathway. Conditional on income, higher wealth is associated with a lower likelihood of belonging to the high disability pathway. Contrary to our expectations, we find no educational gradient in the pathways preceding death. Health inequalities in the last years of life seem to exist especially between individuals with different levels of wealth.

Three Year Functional Trajectories Among Old Age Survivors and Decedents: Dying Eliminates a Racial Disparity

BACKGROUND

Long-term trajectories of disability comparing decedents and survivors and differences by race have not been assessed.

OBJECTIVE

To examine self-reported difficulty in walking a quarter mile and the need for assistance with activities of daily living (ADL) beginning 3 years before death among decedents and age- and gender-matched survivors.

DESIGN

A case-control sample drawn from the Health, Aging and Body Composition Study (Health ABC). Data were collected between 1997 and 2015.

PARTICIPANTS

Of the 1991 participants who died by the end of the study, 1410 were interviewed for 3 years prior to death, including an interview 6 months before dying. Of these, 1379 decedents were successfully matched by age and gender with 1379 survivors and tracked over the same 3-year period.

MAIN MEASURES

Self-reported difficulty walking a quarter mile and the ability to perform activities of daily living without assistance (bathing, dressing, transferring).

KEY RESULTS

Decedents (mean age at death, 84) increased in mobility disability from 44.1% 3 years before death to 69.4% 6 months before death and in ADL disability from 32.9% to 58.4%. Among survivors, mobility disability increased from 31.4% to 40.7% and ADL disability from 17.4% to 31.4%. The proportion of decedents and survivors with mobility disability differed significantly in adjusted models at all assessment points (p < 0.0001). African-American survivors were significantly more disabled than White survivors at all points (p < 0.0001), but trajectories of disability among decedents did not differ by race in the last 18 months of life (p = 0.35).

CONCLUSIONS

Trajectories of self-reported disability differ between survivors and decedents. Older adults who died were more disabled 3 years before death and also had a greater risk of increasing disability over each subsequent 6-month assessment. The gap in disability between African Americans and Whites was erased in the final 1 to 1.5 years before death.

Using the Health and Retirement Study for Disability Policy Research: A Review

The Health and Retirement Study (HRS) is a preeminent data source for research related to the experiences of workers nearing retirement, including the large share of those workers who experience a health shock or disability onset after age 50. In this article, we highlight key information collected from HRS respondents that benefits disability policy research and the body of knowledge that has resulted from this information. Our main goal is to identify from this research experience potential improvements in data collection and documentation that would further strengthen the HRS as a data source for disability policy researchers.

Disability Measurement in the Health and Retirement Study

The Health and Retirement Study (HRS) has provided extensive and detailed national data on disability since it began in 1992, and has been used extensively in studies of disability trends and trajectories. We summarize conceptual frameworks used to characterize disability and review the HRS measures of functioning, work disability, and employer accommodations. HRS survey questions have experienced changes in wording, skip logic, or other design features over the life of the study, and we comment on the analytic challenges posed by those changes. Among our conclusions are (1) work disability and benefit eligibility are important concepts that should be considered for redesign to better reflect current concepts and policy issues; (2) methodological studies of changes in wording or skip logic should be undertaken; and (3) minor additions to survey content in areas such as temporal reference periods or changes in social-participation activities would improve measurement.

A unified framework of demographic time

Demographic thought and practice is largely conditioned by the Lexis diagram, a two-dimensional graphical representation of the identity between age, period, and birth cohort. This relationship does not account for remaining years of life, total length of life, or time of death, whose use in demographic research is both underrepresented and incompletely situated. We describe an identity between these six demographic time measures and describe the sub-identities and diagrams that pertain to this identity. We provide an application of this framework to the measurement of late-life morbidity prevalence. We generalize these relationships to higher order identities derived from an arbitrary number of events in calendar time. Our examples are based on classic human demography, but the concepts we present can reveal patterns and relationships in any event history data, and contribute to the study of human or non-human population dynamics measured on any scale of calendar time.

Growing Older With a Physical Disability: A Special Application of the Successful Aging Paradigm

Objectives

In the United States, the average age of people living with early-acquired physical disabilities is increasing. This cohort is said to be aging with disability and represents a unique population among older adults. Given recent policy efforts designed to merge aging and disability services, it is critical that models of "successful aging" include and are relevant to this population. However, many current definitions of successful aging emphasize avoidance of disability and high levels of physical function as necessary to well-being.

Method

In 9 focus groups, we examined perspectives of "successful aging" in 49 middle-aged and older individuals living with spinal cord injury, multiple sclerosis, muscular dystrophy, or postpolio syndrome. Transcripts were analyzed using a structured qualitative coding approach and Dedoose indexing software.

Results

Participants ranged in age from 45 to 80 years (M = 62) and had lived with their disability diagnosis for an average of 21 years. Analysis revealed 4 primary themes of successful aging: resilience/adaptation, autonomy, social connectedness, and physical health (including access to general and specialty healthcare).

Discussion

Results highlight the need for a nuanced application of the "successful aging" paradigm in this population.

Aging With Disability for Midlife and Older Adults

This analysis brings “aging with disability” into middle and older ages. We study U.S. adults ages 51+ and ages 65+ with persistent disability (physical, household management, personal care; physical limitations, instrumental activities of daily living [IADLs], activities of daily living [ADLs]), using Health and Retirement Study data. Two complementary approaches are used to identify persons with persistent disability, one based directly on observed data and the other on latent classes. Both approaches show that persistent disability is more common for persons ages 65+ than ages 51+ and more common for physical limitations than IADLs and ADLs. People with persistent disability have social and health disadvantages compared to people with other longitudinal experiences. The analysis integrates two research avenues, aging with disability and disability trajectories. It gives empirical heft to government efforts to make aging with disability an age-free (all ages) rather than age-targeted (children and youths) perspective.

Levels of disability in the older population of England: Comparing binary and ordinal classifications

BACKGROUND

Recent studies suggest the importance of distinguishing severity levels of disability. Nevertheless, there is not yet a consensus with regards to an optimal classification.

OBJECTIVE

Our study seeks to advance the existing binary definitions towards categorical/ordinal manifestations of disability.

METHODS

We define disability according to the WHO's International Classification of Functioning, Disability and Health (ICF) using data collected at the baseline wave of the English Longitudinal Study of Aging, a longitudinal study of the non-institutionalized population, living in England. First, we identify cut-off points in the continuous disability score derived from ICF to distinguish disabled from no-disabled participants. Then, we fit latent class models to the same data to find the optimal number of disability classes according to: (i) model fit indicators; (ii) estimated probabilities of each disability item; (iii) association of the predicted disability classes with observed health and mortality.

RESULTS

According to the binary classification criteria, about 32% of both men and women are classified disabled. No optimal number of classes emerged from the latent class models according to model fit indicators. However, the other two criteria suggest that the best-fitting model of disability severity has four classes.

CONCLUSIONS

Our findings contribute to the debate on the usefulness and relevance of adopting a finer categorization of disability, by showing that binary indicators of disability averaged the burden of disability and masked the very strong effect experienced by individuals having severe disability, and were not informative for low levels of disability.

Disability Rises Gradually for a Cohort of Older Americans

OBJECTIVES

We study changes in average disability over nearly two decades for a large epidemiological cohort of older Americans. As some people exit by mortality, do average disability levels for the living cohort rise rapidly, rise gradually, stay steady, or decline?

METHOD

Data are from the Study of Asset and Health Dynamics Among the Oldest Old (AHEAD) cohort for 1993-2010. Cohort members are aged 70+ in 1993 (mean = 77.5 years), and the survivors are aged 87+ in 2010 (mean = 90.2 years). Personal care disability (activities of daily living), household management disability (instrumental activities of daily living), and physical limitations are studied. We study average disability for the living cohort over time and the disability histories for decedent and survivor groups.

RESULTS

Average disability rises gradually over time for the living cohort. Earlier decedent groups have higher average disability than later ones. Near death, disability rises sharply for all decedent groups. Longer surviving groups have less average disability, and slower disability increases, than shorter surviving groups. All results are repeated for younger cohort members (baseline age = 70-79 years), older ones (baseline age = 80+ years), women, and men.

DISCUSSION

As a cohort ages, average disability among living members increases gradually, signaling behavioral, psychological, and biological fitness in very old persons.

Foundations of Activity of Daily Living Trajectories of Older Americans

OBJECTIVES

The disablement process can be viewed conceptually as a progression from disease to impairment to functional limitation and finally disability (frequently operationalized as activity limitation). This article assesses the extent to which early phases of the process are associated with individual-level disability trajectories by age.

METHOD

We use data from seven waves of the Health and Retirement Study, 1998 to 2010, to investigate for individuals aged 65-84 years how baseline sociodemographic characteristics and self-reported disease, pain, and functional limitation (physical, cognitive, or sensory) are related to the dynamics of limitations in activities of daily living (ADLs). Our modeling approach jointly estimates multiperiod trajectories of ADL limitation and mortality and yields estimates of the number of, shapes of, and factors associated with the most common trajectories.

RESULTS

Individual probability of ADL limitation can best be described by three common trajectories. In comparison with disease, pain, and functional limitation, sociodemographic characteristics have weak associations with trajectory group membership. Notably, neither sex nor education is strongly associated with group membership in multivariate models.

DISCUSSION

The analysis confirms the importance of the early phases of the disablement process and their relationships with subsequent trajectories of activity limitation.

A Novel Approach to Identifying Trajectories of Mobility Change in Older Adults

OBJECTIVES

To validate trajectories of late-life mobility change using a novel approach designed to overcome the constraints of modest sample size and few follow-up time points.

METHODS

Using clinical reasoning and distribution-based methodology, we identified trajectories of mobility change (Late Life Function and Disability Instrument) across 2 years in 391 participants age ≥65 years from a prospective cohort study designed to identify modifiable impairments predictive of mobility in late-life. We validated our approach using model fit indices and comparing baseline mobility-related factors between trajectories.

RESULTS

Model fit indices confirmed that the optimal number of trajectories were between 4 and 6. Mobility-related factors varied across trajectories with the most unfavorable values in poor mobility trajectories and the most favorable in high mobility trajectories. These factors included leg strength, trunk extension endurance, knee flexion range of motion, limb velocity, physical performance measures, and the number and prevalence of medical conditions including osteoarthritis and back pain.

CONCLUSIONS

Our findings support the validity of this approach and may facilitate the investigation of a broader scope of research questions within aging populations of varied sizes and traits.