Treatment of death in the analysis of longitudinal studies of gerontological outcomes

Dementia occurring over a 32-year follow-up attributable to hypertension observed at different ages: Implications for dementia prevention

INTRODUCTION

The fraction of dementia attributable to hypertension might vary depending on the age of the population considered and the age through which dementia occurs.

METHODS

In the Atherosclerosis Risk in Communities study, we quantified population attributable fractions (PAF) of dementia by age 80 and 90 from hypertension assessed at ages of 45-54 (n = 7572), 55-64 (n = 12,033), 65-74 (n = 6561), and 75-84 (n = 2086).

RESULTS

The PAF for dementia by age 80 from all non-normal blood pressure at ages 45-54 was 15.3% (95% confidence interval [CI] = 6.9%-22.3%), 19.1% (95% CI = 9.9%-26.9%) at ages 55-64, and 19.9% (95% CI = -4.4%-38.5%) at ages 65-74. The strongest PAFs were from stage 2 hypertension (11.9%-21.3%). For dementia by age 90, PAFs from non-normal blood pressure up through age 75 were smaller (10.9%-13.8%), and non-significant by age 75-84.

DISCUSSION

Interventions targeting hypertension even in early late life might reduce a sizeable proportion of dementia.

HIGHLIGHTS

We estimated prospective population attributable risks of dementia for hypertension. 15%-20% of dementia cases by age 80 are from non-normal blood pressure (BP). Associations between hypertension and dementia persisted through age 75. Midlife to early late-life BP control might reduce a large proportion of dementia.

Self-Reported Dual Sensory Impairment and Subjective Cognitive Complaints Among Older Adults in the 2019 National Health Interview Survey

PURPOSE

Subjective cognitive complaints (SCCs) are associated with poor quality of life, important for clinical care planning and management, and may predict dementia diagnosis. Dual sensory impairment (DSI) is a risk factor for dementia, but whether DSI is associated with SCCs is unknown. We evaluated whether self-reported DSI is associated with SCCs.

METHOD

We performed a cross-sectional analysis of 9,899 community-dwelling respondents aged 60+ years without dementia or depression in the 2019 National Health Interview Survey. Participants self-reported difficulty remembering or concentrating, seeing even when wearing corrective lenses, and hearing even when using a hearing aid. We defined SCCs and sensory impairment for each mode as reporting at least some difficulty. We categorized sensory impairment into no sensory impairment, vision impairment only, hearing impairment only, and DSI. We then estimated weighted prevalence ratios (PRs) of SCCs by impairment category.

RESULTS

After weighting (9,899 participants representing a weighted n = 59,261,749), 12% of participants reported vision impairment only, 19% reported hearing impairment only, and 7% reported DSI. Relative to no impairment, after adjustment for potential confounders, vision impairment (PR = 2.07; 95% confidence interval [CI] [1.79, 2.39]), hearing impairment (PR = 2.26; 95% CI [2.00, 2.55]), and DSI (PR = 3.21; 95% CI [2.83, 3.63]) were associated with an increased prevalence of SCCs.

CONCLUSIONS

In this nationally representative survey of older Americans, DSI was associated with a threefold increased prevalence of SCCs. Although cross-sectional, these data underscore the importance of assessing multiple impairments as exposures when studying subjective cognition in older adults.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21498711.

Management of death-related noncompleters in cluster randomized trials carried out in nursing homes: a methodological review

BACKGROUND

A noncompleter is defined as a participant who leaves a trial before the end of the planned follow-up. Research in nursing homes is highly exposed to this problem because of high death rates.

OBJECTIVES

The aim of this trial is to assess the statistical management of noncompleters in cluster randomized trials carried out in nursing homes.

STUDY DESIGN AND SETTING

A methodological review of published cluster randomized trials.

RESULTS

We selected 37 articles. For 22 (59%) trials, the design was closed-cohort (i.e., participants included all at the same time when randomizing clusters). In those 22 closed-cohort trials, the median follow-up was 6.5 months (interquartile range 4-12). The median noncompleter rate was 19.5% and the median noncompletions due to death was 73.2%. In only one trial were the baseline characteristics of completers and noncompleters compared. Strategies to deal with noncompleters were an inflation of the planned sample size (11 trials), the use of repeated measurements of the outcome (12 trials), and the use of imputation methods when analyzing data (7 trials).

CONCLUSION

In cluster randomized trials of nursing homes, noncompleters are managed as for any missing data, but they are essentially due to death. Methodological and statistical developments and guidance are needed.

Cognitive Reserve and Mild Cognitive Impairment: Predictors and Rates of Reversion to Intact Cognition vs Progression to Dementia

Background and Objectives

Little is known about the effect of education or other indicators of cognitive reserve on the rate of reversion from mild cognitive impairment (MCI) to normal cognition (NC) or the relative rate (RR) of reversion from MCI to NC vs progression from MCI to dementia. Our objectives were to (1) estimate transition rates from MCI to NC and dementia and (2) determine the effect of age, APOE, and indicators of cognitive reserve on the RR of reversion vs progression using multistate Markov modeling.

Methods

We estimated instantaneous transition rates between NC, MCI, and dementia after accounting for transition to death across up to 12 assessments in the Nun Study, a cohort study of religious sisters aged 75+ years. We estimated RRs of reversion vs progression for age, APOE, and potential cognitive reserve indicators: education, academic performance (high school grades), and written language skills (idea density, grammatical complexity).

Results

Of the 619 participants, 472 were assessed with MCI during the study period. Of these 472, 143 (30.3%) experienced at least one reverse transition to NC, and 120 of the 143 (83.9%) never developed dementia (mean follow-up = 8.6 years). In models adjusted for age group and APOE, higher levels of education more than doubled the RR ratio of reversion vs progression. Novel cognitive reserve indicators were significantly associated with a higher adjusted RR of reversion vs progression (higher vs lower levels for English grades: RR ratio = 1.83; idea density: RR ratio = 3.93; and grammatical complexity: RR ratio = 5.78).

Discussion

Knowledge of frequent reversion from MCI to NC may alleviate concerns of inevitable cognitive decline in those with MCI. Identification of characteristics predicting the rate of reversion from MCI to NC vs progression from MCI to dementia may guide population-level interventions targeting these characteristics to prevent or postpone MCI and dementia. Research on cognitive trajectories would benefit from incorporating predictors of reverse transitions and competing events, such as death, into statistical modeling. These results may inform the design and interpretation of MCI clinical trials, given that a substantial proportion of participants may experience improvement without intervention.

Trajectories of Frailty in the 5 Years Prior to Death Among U.S. Veterans Born 1927-1934

BACKGROUND

Electronic frailty indices (eFIs) are increasingly used to identify patients at risk for morbidity and mortality. Whether eFIs capture the spectrum of frailty change, including decline, stability, and improvement, is unknown.

METHODS

In a nationwide retrospective birth cohort of U.S. Veterans, a validated eFI, including 31 health deficits, was calculated annually using medical record and insurance claims data (2002-2012). K-means clustering was used to assign patients into frailty trajectories measured 5 years prior to death.

RESULTS

There were 214 250 veterans born between 1927 and 1934 (mean [SD] age at death = 79.4 [2.8] years, 99.2% male, 90.3% White) with an annual eFI in the 5 years before death. Nine frailty trajectories were identified. Those starting at nonfrail or prefrail had 2 stable trajectories (nonfrail to prefrail, n = 29 786 and stable prefrail, n = 28 499) and 2 rapidly increasing trajectories (prefrail to moderately frail, n = 28 244 and prefrail to severely frail, n = 22 596). Those who were mildly frail at baseline included 1 gradually increasing trajectory (mildly to moderately frail, n = 33 806) and 1 rapidly increasing trajectory (mildly to severely frail, n = 15 253). Trajectories that started at moderately or severely frail included 2 gradually increasing trajectories (moderately to severely frail, n = 27 662 and progressing severely frail, n = 14 478) and 1 recovering trajectory (moderately frail to mildly frail, n = 13 926).

CONCLUSIONS

Nine frailty trajectories, including 1 recovering trajectory, were identified in this cohort of older U.S. Veterans. Future work is needed to understand whether prevention and treatment strategies can improve frailty trajectories and contribute to compression of morbidity toward the end of life.

Understanding Attrition and Bolstering Retention in a Longitudinal Panel of Older Adults: ORANJ BOWL

Background and Objectives

Attrition from longitudinal studies can affect the generalizability of findings especially when studying developmental constructs such as successful aging.

Research Design and Methods

Using data from a 12-year (6-wave) panel of 5,688 older people (aged 50-74 at baseline), we compared people retained in the panel with people lost to follow-up on demographic characteristics and measures of successful aging. After instituting expanded retention strategies at Wave 6 (i.e., a team-based approach, social media, and paid web search engines), we compared different groups of people lost to follow-up (i.e., deceased and withdrawn due to lack of interest) and different types of completers (i.e., full completers vs. lost and reengaged completers).

Results

At baseline, Wave 6 completers were significantly younger, less likely to be African American, more likely to be married, reported higher levels of income and education, were more likely to be working full-time, had less pain and fewer chronic illnesses, and reported higher levels of subjective successful aging and functional ability than those lost to follow-up. Analyses demonstrated differences across groups based on the reason for loss (i.e., deceased, impaired, and not interested). Participants who missed an interview but returned to the panel were significantly different from those who participated in all waves of data collection. Expanded retention efforts improved generalizability, as people returning to the panel reported lower levels of education, lower levels of income, and were more likely to be African American.

Discussion and Implications

Biased attrition within longitudinal research affects the interpretation of study findings, especially when studying developmental outcomes. However, expanded retention strategies can reduce bias and loss and should be used to enhance retention efforts in longitudinal work.

The potential for complex computational models of aging

The gradual accumulation of damage and dysregulation during the aging of living organisms can be quantified. Even so, the aging process is complex and has multiple interacting physiological scales - from the molecular to cellular to whole tissues. In the face of this complexity, we can significantly advance our understanding of aging with the use of computational models that simulate realistic individual trajectories of health as well as mortality. To do so, they must be systems-level models that incorporate interactions between measurable aspects of age-associated changes. To incorporate individual variability in the aging process, models must be stochastic. To be useful they should also be predictive, and so must be fit or parameterized by data from large populations of aging individuals. In this perspective, we outline where we have been, where we are, and where we hope to go with such computational models of aging. Our focus is on data-driven systems-level models, and on their great potential in aging research.

The effects of socioeconomic conditions on old-age mortality within shared disability pathways

Objective

How disability manifests itself in an individual is a highly complex process influenced by a wide range of individual and environmental factors. Its complexity makes the search for generalizable characteristics of the disablement process a challenging task. Consequentially, little is known about how the effect on other health outcomes such as life expectancy are modified after the onset of chronic ailments. In this paper we posit an alternative approach to generalize health trajectories of older people with disability and then analyze how socioeconomic conditions affect the longevity within these trajectory groups.

Methods

Individual level information about the first three successive onsets of chronic disability after age 50 is transformed into state-sequences. We extract trajectory groups based on onset time and the time spent in a certain state. Mortality hazards are then estimated with a Gompertz proportional hazards model to compare effects of different socioeconomic measures within the trajectory groups.

Results

Three distinct trajectory groups are identified, the mild (1), the early severe (2), and late severe (3) pathway. Estimates of the mortality analysis suggest that social inequalities in longevity are less pronounced after onset of old-age disability. We found a consistent survival prolonging effect for individuals who engage in daily activities (such as meeting with friends, walking) that ranged between 33.2% and 77.3%. The importance of other variables varies between trajectory groups.

Discussion

This study shows how health trajectories of individuals with disability can be generalized when information on the onset and severity of single conditions is available. Such an approach may help us to better predict health and care expenditures and help families and individuals with their personal care planning. The findings from the subsequent survival analysis suggest a substantial reduction of socioeconomic mortality differences after onset of old-age disability, which appears to be independent of its nature.

Genetics of physiological dysregulation: findings from the long life family study using joint models

Recently, Mahalanobis distance (D_M) was suggested as a statistical measure of physiological dysregulation in aging individuals. We constructed D_M variants using sets of biomarkers collected at the two visits of the Long Life Family Study (LLFS) and performed joint analyses of longitudinal observations of D_M and follow-up mortality in LLFS using joint models. We found that D_M is significantly associated with mortality (hazard ratio per standard deviation: 1.31 [1.16, 1.48] to 2.22 [1.84, 2.67]) after controlling for age and other covariates. GWAS of random intercepts and slopes of D_M estimated from joint models found a genome-wide significant SNP (rs12652543, p=7.2×10^-9) in the TRIO gene associated with the slope of D_M constructed from biomarkers declining in late life. Review of biological effects of genes corresponding to top SNPs from GWAS of D_M slopes revealed that these genes are broadly involved in cancer prognosis and axon guidance/synapse function. Although axon growth is mainly observed during early development, the axon guidance genes can function in adults and contribute to maintenance of neural circuits and synaptic plasticity. Our results indicate that decline in axons' ability to maintain complex regulatory networks may potentially play an important role in the increase in physiological dysregulation during aging.

Real-world outcomes of rivaroxaban treatment in elderly Japanese patients with nonvalvular atrial fibrillation

Direct oral anticoagulants (DOACs), such as rivaroxaban, reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF). However, it is still unclear whether the stroke reduction benefit outweighs the bleeding risk in elderly Japanese patients with NVAF. The Xarelto Post-Authorization Safety and Effectiveness Study in Japanese Patients with Atrial Fibrillation (XAPASS) was a real-world, prospective observational, post-marketing surveillance study on the safety and effectiveness of rivaroxaban in Japanese clinical practice. This sub-analysis evaluated the clinical outcomes of elderly patients aged ≥ 75 years. At the 1-year follow-up, there were 4,685 (48.91%) and 4,893 (51.09%) patients aged ≥ 75 and < 75 years, respectively. Safety and effectiveness outcomes were compared between patients aged ≥ 75 years and those aged < 75 years, and among 3 elderly sub-populations (age ranges: 75-79, 80-84, and ≥ 85 years). Patients aged ≥ 75 years had higher rates of major bleeding [2.22 vs. 1.35 events per 100 patient-years, hazard ratio (HR) 1.63, 95% confidence interval (CI) 1.17-2.28] and composite of stroke (ischemic or hemorrhagic)/non-central nervous system (non-CNS) systemic embolism (SE)/myocardial infarction (MI) (2.41 vs. 1.21 events per 100 patient-years, HR 1.97, 95% CI 1.40-2.77) compared to patients aged < 75 years. Intracranial hemorrhage rates were < 1 event per 100 patient-years in both groups (0.85 vs. 0.59 events per 100 patient-years, HR 1.43, 95% CI 0.85-2.40). Kaplan-Meier curves of major bleeding and stroke/non-CNS SE/MI showed that no significant differences of cumulative event rates were identified among the 3 elderly sub-populations. Stepwise Cox regression analyses revealed that creatinine clearance (CrCl) (<50 mL/min), hepatic impairment, and hypertension were specific predictors for major bleeding and no specific predictors were found for stroke/non-CNS SE/MI in patients aged ≥ 75 years. In conclusion, safety and effectiveness event rates were higher in patients aged ≥ 75 years compared with those aged < 75 years, yet, no distinct differences were observed among the 3 elderly sub-populations.

Childhood sexual abuse, poly-victimization and internalizing disorders across adulthood and older age: Findings from a 25-year longitudinal study

BACKGROUND

We aimed to investigate associations between childhood sexual abuse and maltreatment and internalizing disorders (anxiety, depression, PTSD) across adulthood.

METHODS

Following a postal survey of 2220 women, a subsample was selected to participate in an interview. The subsample included 276 women reporting childhood sexual abuse and 221 women with no reported history of childhood sexual abuse. Interviews were repeated six and 25 years following the first interview. Internalizing disorders were assessed using ICD-8 and DSM-III criteria.

RESULTS

There was a lower probability of having an internalizing disorder at older ages than younger ages for all women, regardless of maltreatment history. Latent class analysis was used to define three classes (no/low maltreatment, sexual abuse, poly-victimisation). Compared with no/low maltreatment, a history of childhood sexual abuse was associated with almost double the risk of an internalizing disorder and a history of poly-victimisation was associated with over four times the risk of an internalizing disorder. Childhood sexual abuse and poly-victimisation remained associated with an elevated risk of a disorder in older age.

LIMITATIONS

Findings are limited by attrition (39% participated at Time 3), low prevalence of severe physical abuse, and changes in assessment practice of childhood maltreatment and mental disorder in the past 30 years.

CONCLUSIONS

Screening and treatment for internalizing disorders in women with histories of childhood maltreatment remains important in older aged populations.

The Competing Risk of Death in Longitudinal Geriatric Outcomes

OBJECTIVES

To address the competing risk of death in longitudinal studies of older persons, we demonstrate sensitivity analyses that evaluate robustness of associations between exposures and three outcome types: dichotomous, count, and time to event.

DESIGN

A secondary analysis of data from a prospective cohort study.

SETTING

Community-based data from the Precipitating Events Project in New Haven, CT.

PARTICIPANTS

Persons 70 years and older who were initially community dwelling and without disability in the four basic activities of daily living (N = 754).

MEASUREMENTS

Missing outcome values from decedents were multiply imputed under different scenarios. Three outcomes were examined: dichotomous fall-related hospitalization (FRH); a count (0-13) of total disability in each of the 6 months after discharge; and days to functional recovery among those whose disability worsened in the hospital. Each outcome had a different exposure: for dichotomous, indicators of being overweight or obese; for count, frailty from the Fried phenotype (0-5, where not frail = 0, prefrail = 1-2, and frail = 3-5); for days to recovery, vision impairment.

RESULTS

For FRH, being overweight or obese lost significance when decedents were kept in the risk pool without outcome events for over 10 years. For disability count and time to recovery, with follow-up of 6 months, exposures only lost significance under highly implausible clinical scenarios.

CONCLUSION

This method facilitates evaluation of potential bias from the competing risk of death in longitudinal studies for nondeath outcomes that are not necessarily time to event. Results suggest that death introduces substantive bias when long-term follow-up results in cumulatively high levels of mortality. J Am Geriatr Soc 67:357-362, 2019.

Identifying and Implementing Endpoints for Geriatric Mice

The types of changes in physical appearance and behavior that occur in elderly people similarly develop in elderly animals. Signs and symptoms that might cause concern in younger people or mice may be normal in their elderly but generally healthy counterparts. Although numerous scoring methods have been developed to assess rodent health, these systems were often designed for young adults used in specific types of research, such as cancer or neurologic studies, and therefore may be suboptimal for assessing aging rodents. Approaches known as frailty assessments provide a global evaluation of the health of aged mice, rats, and people, and mouse frailty scores correlate well with the likelihood of death. Complementing frailty assessment, prediction of imminent death in aged mice can often be accomplished by focusing on 2 objective parameters-body weight and temperature. Before they die, many (but not all) mice develop marked reductions in body weight and temperature, thus providing signs that close monitoring, intervention, or preemptive euthanasia may be necessary. Timely preemptive euthanasia allows antemortem collection of data and samples that would be lost if spontaneous death occurred; preemptive euthanasia also limits terminal suffering. These approaches to monitoring declining health and predicting death in elderly research mice can aid in establishing and implementing timely interventions that both benefit the research and reduce antemortem suffering.

Genomic African and Native American Ancestry and 15-Year Cognitive Trajectory: Bambui Study, Brazil

OBJECTIVES

To investigate the association between African and Native American genomic ancestry and long-term cognitive trajectories in admixed Brazilians.

DESIGN

Population-based longitudinal study.

SETTING

Bambui-Epigen (Brazil) cohort study.

PARTICIPANTS

Adults aged 60 and older (N=1,215) MEASUREMENTS: Participants were followed from January 1997 to December 2011. Cognitive function was assessed annually using the Mini-Mental State Examination (MMSE), totaling 12,208 measurements. We used linear mixed-effects pattern models to assess MMSE score trajectories. Ancestry was assessed using a genome-wide approach.

RESULTS

After adjustments for covariates, the highest quintile of African ancestry was associated with poorer baseline cognitive performance (β=-0.73, 95% confidence interval (CI)=-1.36 to -0.11) but not with cognitive trajectory. Educational level modified the baseline association between highest African ancestry and cognitive performance in that the association was observed only in those with very low (<4 years) education (β=-1.13, 95% CI=-2.02 to -0.23). No association was found between Native American ancestry and baseline cognitive function or its trajectory.

CONCLUSION

Genomic African and Native American ancestry levels had no prognostic value for age-related cognitive decline in this admixed population.

Depressive symptoms, emotional support and activities of daily living disability onset: 15-year follow-up of the Bambuí (Brazil) Cohort Study of Aging

Psychosocial factors appear to be associated with increased risk of disability in later life. However, there is a lack of evidence based on long-term longitudinal data from Western low-middle income countries. We investigated whether psychosocial factors at baseline predict new-onset disability in long term in a population-based cohort of older Brazilians adults. We used 15-year follow-up data from 1,014 participants aged 60 years and older of the Bambuí (Brazil) Cohort Study of Aging. Limitations on activities of daily living (ADL) were measured annually, comprising 9,252 measures. Psychosocial factors included depressive symptoms, social support and social network. Potential covariates included sociodemographic characteristics, lifestyle, cognitive function and a physical health score based on 10 self-reported and objectively measured medical conditions. Statistical analysis was based on competitive-risk framework, having death as the competing risk event. Baseline depressive symptoms and emotional support from the closest person were both associated with future ADL disability, independently of potential covariates wide range. The findings showed a clear graded association, in that the risk gradually increased from low emotional support alone (sub-hazard ratio - SHR = 1.11; 95%CI: 1.01; 1.45) to depressive symptoms alone (SHR = 1.52; 95%CI: 1.13; 2.01) and then to both factors combined (SHR = 1.61; 95%CI: 1.18; 2.18). Marital status and social network size were not associated with incident disability. In a population of older Brazilian adults, lower emotional support and depressive symptoms have independent predictive value for subsequent disability in very long term.

Predictors of long-term care among nonagenarians: the Vitality 90 + Study with linked data of the care registers

BACKGROUND

The need for long-term care services increases with age. However, little is known about the predictors of long-term care (LTC) entry among the oldest old.

AIMS

Aim of this study was to assess predictors of LTC entry in a sample of men and women aged 90 years and older.

METHODS

This study was based on the Vitality 90 + Study, a population-based study of nonagenarians in the city of Tampere, Finland. Baseline information about health, functioning and living conditions were collected by mailed questionnaires. Information about LTC was drawn from care registers during the follow-up period extending up to 11 years. Cox regression models were used for the analyses, taking into account the competing risk of mortality.

RESULTS

During the mean follow-up period of 2.3 years, 844 (43%) subjects entered first time into LTC. Female gender (HR 1.39, 95% CI 1.14-1.69), having at least two chronic conditions (HR 1.24, 95% CI 1.07-1.44), living alone (HR 1.37, 95% CI 1.15-1.63) and help received sometimes (HR 1.23, 95% CI 1.02-1.49) or daily (HR 1.68, 95% CI 1.38-2.04) were independent predictors of LTC entry.

CONCLUSION

Risk of entering into LTC was increased among women, subjects with at least two chronic conditions, those living alone and with higher level of received help. Since number of nonagenarians will increase and the need of care thereby, it is essential to understand predictors of LTC entry to offer appropriate care for the oldest old in future.

Can measures of physical performance in mid-life improve the clinical prediction of disability in early old age? Findings from a British birth cohort study

BACKGROUND

Poor performance in physical tests such as grip strength and walking speed is a risk factor for disability in old age, although whether such measures improve the discrimination of clinical prediction models when traditional clinical risk factors are already known is not clear. The prevalence of disability in mid-life is relatively low and hence screening in this age group may present an opportunity for early identification of those at increased future risk who may benefit most from preventative interventions.

METHODS

Data were drawn from two waves of the Medical Research Council National Survey of Health and Development. We examined whether several chronic conditions, poor health behaviours and lower scores on three measures of physical performance (grip strength, chair rise speed and standing balance time) at age 53 were associated with self-reported mobility and/or personal care disability at age 69. We used the area under the curve statistic (AUC) to assess model discrimination.

RESULTS

At age 69, 44% (826/1855) of participants reported mobility and/or personal care disability. Our final clinical prediction model included sex, knee osteoarthritis, taking 2+ medications, smoking, increased BMI and poor performance in all three physical tests, with an AUC of 0.740 compared with 0.708 for a model which did not include the performance measures.

CONCLUSION

Measures of physical performance in midlife improve discrimination in clinical prediction models for disability over 16 years. Importantly, these and similar measures are also potential targets of future diet, exercise and pharmacological intervention in mid-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.

Diabetes mitigates the role of memory complaint in predicting dementia risk: Results from the Prevention of Alzheimer's Disease with Vitamin E and Selenium Study

BACKGROUND

Subjective memory complaints (SMCs) are associated with increased risk of dementia in older adults, but the role of comorbidities in modifying this risk is unknown.

OBJECTIVES

To assess whether comorbidities modify estimated dementia risk based on SMCs.

DESIGN

The Prevention of Alzheimer's Disease with Vitamin E and Selenium Study (PREADVISE) was designed as an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT), a randomized, multi-center prostate cancer prevention trial with sites in the Unites States, Puerto Rico, and Canada. In 2009, PREADVISE and SELECT were changed into cohort studies.

SETTING

Secondary analysis of PREADVISE data.

PARTICIPANTS

PREADVISE recruited 7,540 non-demented male volunteers from participating SELECT sites from 2002 to 2009. SMCs, demographics, and comorbidities including hypertension, diabetes, coronary artery bypass graft (CABG), stroke, sleep apnea, and head injury were ascertained by participant interview.

MEASUREMENTS

Cox models were used to investigate whether baseline comorbidities modified hazard ratios (HR) for SMC-associated dementia risk using two methods: (1) we included one interaction term between SMC and a comorbidity in the model at a time, and (2) we included all two-way interactions between SMC and covariates of interest and reduced the model by "backward" selection. SMC was operationalized as any complaint vs. no complaint.

RESULTS

Baseline SMCs were common (23.6%). In the first analyses, with the exception of stroke, presence of self-reported comorbidities was associated with lower estimated HR for dementia based on SMC status (complaint vs. no complaint), but this difference was only significant for diabetes. In the second analysis, the two-way interactions between SMC and race as well as SMC and diabetes were significant. Here, black men without diabetes who reported SMC had the highest estimated dementia risk (HR=5.05, 95% CI 2.55-10.00), while non-black men with diabetes who reported SMC had the lowest estimated risk (HR=0.71, 95% CI 0.35-1.41).

CONCLUSIONS

SMCs were more common among men with comorbidities, but these complaints appeared to be less predictive of dementia risk than those originating from men without comorbidities, suggesting that medical conditions such as diabetes may explain SMCs that are unrelated to an underlying neurodegenerative process.

Prevalence of frailty in Japan: A systematic review and meta-analysis

Japan's population is aging more rapidly than that of any other country. Frailty has recently been recognized as an important priority. Understanding the basic epidemiology of frailty in Japan, which is an example of a rapidly aging society, will be beneficial for Japan as well as other countries expecting an aging population. A systematic literature search of 11 electronic databases was conducted in March 2016 using a comprehensive set of Medical Subject Heading and text terms for any studies published in 2000 or later that report the prevalence of frailty among Japanese community-dwelling older people aged 65 years or older. A total of 1529 studies were identified in the systematic search, of which five studies were included in this review. The pooled prevalence of frailty, prefrailty, and robustness was 7.4% (95% confidence interval [CI], 6.1%–9.0%), 48.1% (95% CI, 41.6%–54.8%), and 44.4% (95% CI, 37.2%–51.7%), respectively. A significant degree of heterogeneity was observed. There was no evidence of publication bias. Age-stratified meta-analyses of four studies showed the pooled prevalence of frailty was 1.9%, 3.8%, 10.0%, 20.4%, and 35.1% for those aged 65–69, 70–74, 75–79, 80–84, and ≥85 years, respectively. Pooled prevalence of frailty was 8.1% for women and 7.6% for men. This review showed an overall pooled prevalence of frailty among Japanese community-dwelling older people of 7.4%. The age-stratified analysis suggested that Japanese older people are less frail before their late 70's but frailer in later life than older people in other countries. These findings provide important basic information for all parties involved in Japanese frailty research.

•

Frailty is an important priority in Japan, where the population is aging rapidly.

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Japan is a good example of a rapidly aging society for frailty research.

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Five studies were included in this systematic review and meta-analysis study.

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Pooled prevalence of frailty in Japanese in the community aged >65 years is 7.4%.

Identification of risk factors for hospital admission using multiple-failure survival models: a toolkit for researchers

BACKGROUND

The UK population is ageing; improved understanding of risk factors for hospital admission is required. Linkage of the Hertfordshire Cohort Study (HCS) with Hospital Episode Statistics (HES) data has created a multiple-failure survival dataset detailing the characteristics of 2,997 individuals at baseline (1998-2004, average age 66 years) and their hospital admissions (regarded as 'failure events') over a 10 year follow-up. Analysis of risk factors using logistic regression or time to first event Cox modelling wastes information as an individual's admissions after their first are disregarded. Sophisticated analysis techniques are established to examine risk factors for admission in such datasets but are not commonly implemented.

METHODS

We review analysis techniques for multiple-failure survival datasets (logistic regression; time to first event Cox modelling; and the Andersen and Gill [AG] and Prentice, Williams and Peterson Total Time [PWP-TT] multiple-failure models), outline their implementation in Stata, and compare their results in an analysis of housing tenure (a marker of socioeconomic position) as a risk factor for different types of hospital admission (any; emergency; elective; >7 days). The AG and PWP-TT models include full admissions histories in the analysis of risk factors for admission and account for within-subject correlation of failure times. The PWP-TT model is also stratified on the number of previous failure events, allowing an individual's baseline risk of admission to increase with their number of previous admissions.

RESULTS

All models yielded broadly similar results: not owner-occupying one's home was associated with increased risk of hospital admission. Estimated effect sizes were smaller from the PWP-TT model in comparison with other models owing to it having accounted for an increase in risk of admission with number of previous admissions. For example, hazard ratios [HR] from time to first event Cox models were 1.67(95 % CI: 1.36,2.04) and 1.63(95 % CI:1.36,1.95) for not owner-occupying one's home in relation to risk of emergency admission or death among women and men respectively; corresponding HRs from the PWP-TT model were 1.34(95 % CI:1.15,1.56) for women and 1.23(95 % CI:1.07,1.41) for men.

CONCLUSION

The PWP-TT model may be implemented using routine statistical software and is recommended for the analysis of multiple-failure survival datasets which detail repeated hospital admissions among older people.

A longitudinal, observational study with many repeated measures demonstrated improved precision of individual survival curves using Bayesian joint modeling of disability and survival

BACKGROUND/STUDY CONTEXT: It has not been previously demonstrated whether Bayesian joint modeling (BJM) of disability and survival can, under certain conditions, improve precision of individual survival curves.

METHODS

A longitudinal, observational study wherein 754 initially nondisabled community-dwelling adults in greater New Haven, Connecticut, were observed on a monthly basis for over 10 years.

RESULTS

In this study, BJM exploited many monthly observations to demonstrate, relative to a separate survival model with adjustment, improved precision of individual survival curves, permitting detection of significant differences between survival curves of two similar individuals. The gain in precision was lost when using only those observations from intervals of 6, 9, or 12 months.

CONCLUSION

When there are many repeated measures, BJM of longitudinal functional disability and interval-censored survival can potentially increase the precision of individual survival curves relative to those from a separate survival model. This may facilitate the identification of significant differences between individual survival curves, a useful result usually precluded by the large variability inherent to individual-level estimates from stand-alone survival models.

Hospital Readmission Following Discharge From Inpatient Rehabilitation for Older Adults With Debility

BACKGROUND

Debility accounts for 10% of inpatient rehabilitation cases among Medicare beneficiaries. Debility has the highest 30-day readmission rate among 6 impairment groups most commonly admitted to inpatient rehabilitation.

OBJECTIVE

The purpose of this study was to examine rates, temporal distribution, and factors associated with hospital readmission for patients with debility up to 90 days following discharge from inpatient rehabilitation.

DESIGN

A retrospective cohort study was conducted using records for 45,424 Medicare fee-for-service beneficiaries with debility discharged to community from 1,199 facilities during 2006-2009.

METHODS

Cox proportional hazard regression models were used to estimate hazard ratios for readmission. Schoenfeld residuals were examined to identify covariate-time interactions. Factor-time interactions were included in the full model for Functional Independence Measure (FIM) discharge motor functional status, comorbidity tier, and chronic pulmonary disease. Most prevalent reasons for readmission were summarized by Medicare severity diagnosis related groups.

RESULTS

Hospital readmission rates for patients with debility were 19% for 30 days and 34% for 90 days. The highest readmission count occurred on day 3 after discharge, and 56% of readmissions occurred within 30 days. A higher FIM discharge motor rating was associated with lower hazard for readmissions prior to 60 days (30-day hazard ratio=0.987; 95% confidence interval=0.986, 0.989). Comorbidities with hazard ratios >1.0 included comorbidity tier and 11 Elixhauser conditions, 3 of which (heart failure, renal failure, and chronic pulmonary disease) were among the most prevalent reasons for readmission.

LIMITATIONS

Analysis of Medicare data permitted only use of variables reported for administrative purposes. Comorbidity data were analyzed only for inpatient diagnoses.

CONCLUSIONS

One-third of patients were readmitted to acute hospitals within 90 days following rehabilitation for debility. Protective effect of greater motor function was diminished by 60 days after discharge from inpatient rehabilitation.

Elevated Hospitalization Risk of Assisted Living Residents With Dementia in Alberta, Canada

OBJECTIVES

Assisted living (AL) is an increasingly used residential option for older adults with dementia; however, lower staffing rates and service availability raise concerns that such residents may be at increased risk for adverse outcomes. Our objectives were to determine the incidence of hospitalization over 1 year for dementia residents of designated AL (DAL) facilities, compared with long-term care (LTC) facilities, and identify resident- and facility-level predictors of hospitalization among DAL residents.

METHODS

Participants were 609 DAL (mean age 85.7 ± 6.6 years) and 691 LTC (86.4 ± 6.9 years) residents with dementia enrolled in the Alberta Continuing Care Epidemiological Studies. Research nurses completed a standardized comprehensive assessment of residents and interviewed family caregivers at baseline (2006-2008) and 1 year later. Standardized administrator interviews provided facility level data. Hospitalization was determined via linkage with the provincial Inpatient Discharge Abstract Database. Multivariable Cox proportional hazards models were used to identify predictors of hospitalization.

RESULTS

The cumulative annual incidence of hospitalization was 38.6% (34.5%-42.7%) for DAL and 10.3% (8.0%-12.6%) for LTC residents with dementia. A significantly increased risk for hospitalization was observed for DAL residents aged 90+ years, with poor social relationships, less severe cognitive impairment, greater health instability, fatigue, high medication use (11+ medications), and 2+ hospitalizations in the preceding year. Residents from DAL facilities with a smaller number of spaces, no chain affiliation, and from specific health regions showed a higher risk of hospitalization.

CONCLUSIONS

DAL residents with dementia had a hospitalization rate almost 4-fold higher than LTC residents with dementia. Our findings raise questions about the ability of some AL facilities to adequately address the needs of cognitively impaired residents and highlight potential clinical, social, and policy areas for targeted interventions to reduce hospitalization risk.

Association of hearing impairment with declines in physical functioning and the risk of disability in older adults

BACKGROUND

Identifying factors associated with functional declines in older adults is important given the aging of the population. We investigated if hearing impairment is independently associated with objectively measured declines in physical functioning in a community-based sample of older adults.

METHODS

Prospective observational study of 2,190 individuals from the Health, Aging, and Body Composition study. Participants were followed annually for up to 11 visits. Hearing was measured with pure-tone audiometry. Physical functioning and gait speed were measured with the Short Physical Performance Battery (SPPB). Incident disability and requirement for nursing care were assessed semiannually through self-report.

RESULTS

In a mixed-effects model, greater hearing impairment was associated with poorer physical functioning. At both Visit 1 and Visit 11, SPPB scores were lower in individuals with mild (10.14 [95% CI 10.04-10.25], p < .01; 7.35 [95% CI 7.12-7.58], p < .05) and moderate or greater hearing impairment (10.04 [95% CI 9.90-10.19], p < .01; 7.00 [95% CI 6.69-7.32], p < .01) than scores in normal hearing individuals (10.36 [95% CI 10.26-10.46]; 7.71 [95% CI 7.49-7.92]). We observed that women with moderate or greater hearing impairment had a 31% increased risk of incident disability (Hazard ratio [HR] =1.31 [95% CI 1.08-1.60], p < .01) and a 31% increased risk of incident nursing care requirement (HR = 1.31 [95% CI 1.05-1.62], p = .02) compared to women with normal hearing.

CONCLUSIONS

Hearing impairment is independently associated with poorer objective physical functioning in older adults, and a 31% increased risk for incident disability and need for nursing care in women.

Persistence and Prognostic Implications of Orthostatic Hypotension in Older Individuals with Mild-to-Moderate Dementia

AIM

To study the course and prognostic implications of orthostatic hypotension (OH) in older individuals with mild-to-moderate dementia.

METHODS

Referrals to outpatient clinics specialising in old age psychiatry and geriatric medicine in the counties of Rogaland and Hordaland in western Norway with a first-time diagnosis of mild dementia were consecutively asked for inclusion. A total of 211 participants underwent a comprehensive baseline assessment with annual follow-ups. Patients with OH at both baseline and the 1-year follow-up were classified as having persistent OH. Outcome measures were the Mini-Mental State Examination (MMSE), the Clinical Dementia Rating sum of boxes (CDR-SB), and time to death.

RESULTS

From baseline to the 4-year follow-up, 30-45% of the participants had OH at each follow-up. In multivariable analysis, persistent OH was not significantly associated with either the longitudinal course of MMSE or CDR-SB scores or survival.

CONCLUSIONS

OH was moderately prevalent over 4 years in older individuals with mild dementia, and persistent OH did not predict either cognitive or functional decline or survival.

A dynamic trajectory class model for intensive longitudinal categorical outcome

This paper presents a novel dynamic latent class model for a longitudinal response that is frequently measured as in our prospective study of older adults with monthly data on activities of daily living for more than 10 years. The proposed method is especially useful when the longitudinal response is measured much more frequently than other relevant covariates. The trajectory classes are latent classes that represent distinct temporal patterns of the longitudinal response wherein an individual may remain in a trajectory class or switch to another as the class membership predictors are updated periodically over time. The identification of a common set of trajectory classes allows changes among the temporal patterns to be distinguished from local fluctuations in the response. Within a trajectory class, the longitudinal response is modeled by a class-specific generalized linear mixed model. An informative event such as death is jointly modeled by class-specific probability of the event through shared random effects with that for the longitudinal response. We do not impose the conditional independence assumption given the classes. We illustrate the method by analyzing the change over time in activities of daily living trajectory class among 754 older adults with 70,500 person-months of follow-up in the Precipitating Events Project. We also investigate the impact of jointly modeling the class-specific probability of the event on the parameter estimates in a simulation study. The primary contribution of our paper is the periodic updating of trajectory classes for a longitudinal categorical response without assuming conditional independence.

Younger age distribution of cervical cancer incidence among survivors of pediatric and young adult cancers

BACKGROUND

Pediatric and young adult (PAYA) cancer survivors may have an earlier onset of chronic diseases compared with the general population. We compared the age at cervical cancer diagnosis between PAYA cancer survivors and females in the general US population.

METHODS

We used longitudinal data from 9 population-based registries of the Surveillance, Epidemiology, and End Results program collected between 1973 and 2010. PAYA cancer survivors were females diagnosed with any cancer before age 30 years, survived at least 5 years post-diagnosis, and were subsequently diagnosed with invasive cervical cancer (n=46). The general US population comprised females who were diagnosed with invasive cervical cancer as the primary malignancy (n=26,956). We estimated the difference in median age at diagnosis (ß₅₀) and bootstrap 95% confidence limits (CL) of invasive cervical cancer after adjustment for year of diagnosis and race.

RESULTS

The median age at diagnosis of invasive cervical cancer was 33 years for female PAYA cancer survivors and 40 years for females in the general US population (ß50=-7.0, 95% CL: -11, -3.2). Similar differences were observed across subgroups of stage and histologic subtype of invasive cervical cancer.

CONCLUSION

Our results suggest that PAYA cancer survivors are diagnosed with invasive cervical cancer at a substantially younger age compared with females without a prior cancer diagnosis in the general US population. This issue warrants further study, and could have implications for determining age at initiation or frequency of cervical cancer screening if younger age at diagnosis is attributable to an underlying biological phenomenon.

Examining late-life functional limitation trajectories and their associations with underlying onset, recovery, and mortality

OBJECTIVES

Identify common trajectories of physical functional limitation and mortality among Taiwanese 50 and older as they age, link these to underlying transitions in onset, recovery, and mortality, and assess associations between trajectories and a set of risk factors.

METHOD

Longitudinal data from 4 waves of the Survey of Health and Living Status of the Middle-Aged and Elderly in Taiwan, collected between 1996 and 2007, are analyzed using a summary measure indicating difficulty with one or more of 7 physical functions. A group-based trajectory model identifies common trajectories. Shorter term transition probabilities that underlie multiperiod trajectories are examined. Multinomial regression associates risk factors with trajectory group membership.

RESULTS

Best fitting the data is a model with 3 groups characterized as early, mid, and late onset of limitation. Roughly half the population follows the trajectory of mid onset and a quarter each of the other 2. Females and those least educated are most likely to belong to the early-onset group.

DISCUSSION

The analysis advances understanding of late-life functioning by focusing on the heterogeneity of functional limitation experience, appropriately accounting for the relation between functional limitation and mortality and linking long-term patterns with short-term changes in functional limitation.

The health and service needs of older veterans: a qualitative analysis

BACKGROUND

With substantial numbers of older people within the Australian veteran population continuing to age well within the community, appropriate planning of community support and health services is important for this ageing population.

OBJECTIVE

The purpose of this research study was to investigate the health and service usage of a group of older Australian war veterans who receive Australian Government support for their health-care needs and conditions.

DESIGN

This paper reports on qualitative data gathered from the longitudinal MELSHA study. Utilizing thematic analysis and the theoretical framework of locus of control, this article reports on 25 qualitative interviews of veterans and their widows about their DVA-related health and service usage.

RESULTS

Participants within this study were determined to maintain a sense of control and independence in relation to their living circumstances and service usage. In doing so, they attempted to maintain their current community living circumstances and independence while minimizing their utilization of services and perceived 'burden' on family members and friends. Participants accepted that a decline in health status was inevitable, but engaged in a number of different strategies to maintain their current way of life for as long as possible.

DISCUSSION & CONCLUSION

Participants, while valuing an internal locus of control, generally engaged in an integrative locus of control to maintain a sense of control and independence in their daily lives. In addition, participants were very grateful of the services provided by the DVA and acknowledged their role in maintaining their independence within the community.

High rates of hospital admission among older residents in assisted living facilities: opportunities for intervention and impact on acute care

BACKGROUND

Little is known about health or service use outcomes for residents of Canadian assisted living facilities. Our objectives were to estimate the incidence of admission to hospital over 1 year for residents of designated (i.e., publicly funded) assisted living (DAL) facilities in Alberta, to compare this rate with the rate among residents of long-term care facilities, and to identify individual and facility predictors of hospital admission for DAL residents.

METHODS

Participants were 1066 DAL residents (mean age ± standard deviation 84.9 ± 7.3 years) and 976 longterm care residents (85.4 ± 7.6 years) from the Alberta Continuing Care Epidemiological Studies (ACCES). Research nurses completed a standardized comprehensive assessment for each resident and interviewed family caregivers at baseline (2006 to 2008) and 1 year later. We used standardized interviews with administrators to generate facility- level data. We determined hospital admissions through linkage with the Alberta Inpatient Discharge Abstract Database. We used multivariable Cox proportional hazards models to identify predictors of hospital admission.

RESULTS

The cumulative annual incidence of hospital admission was 38.9% (95% confidence interval [CI] 35.9%- 41.9%) for DAL residents and 13.7% (95% CI 11.5%-15.8%) for long-term care residents. The risk of hospital admission was significantly greater for DAL residents with greater health instability, fatigue, medication use (11 or more medications), and 2 or more hospital admissions in the preceding year. The risk of hospital admission was also significantly higher for residents from DAL facilities with a smaller number of spaces, no licensed practical and/ or registered nurses on site (or on site less than 24 hours a day, 7 days a week), no chain affiliation, and from select health regions.

INTERPRETATION

The incidence of hospital admission was about 3 times higher among DAL residents than among long-term care residents, and the risk of hospital admission was associated with a number of potentially modifiable factors. These findings raise questions about the complement of services and staffing required within assisted living facilities and the potential impact on acute care of the shift from long-term care to assisted living for the facility-based care of vulnerable older people.

Relationship between pain and chronic illness among seriously ill older adults: expanding role for palliative social work

Confronting the issue of pain among chronically ill older adults merits serious attention in light of mounting evidence that pain in this population is often undertreated or not treated at all (Institute of Medicine, 2011 ). The relationship between pain and chronic illness among adults age 50 and over was examined in this study through the use of longitudinal data from the University of Michigan Health and Retirement Study, sponsored by the National Institute on Aging and the Social Security Administration. Findings suggested positive associations between pain and chronic disease, pain and multimorbidity, as well as an inverse association between pain and education. Policy implications for workforce development and public health are many, and amplification of palliative social work roles to relieve pain and suffering among seriously ill older adults at all stages of the chronic illness trajectory is needed.

Self-reported head injury and risk of late-life impairment and AD pathology in an AD center cohort

AIMS

To evaluate the relationship between self-reported head injury and cognitive impairment, dementia, mortality, and Alzheimer's disease (AD)-type pathological changes.

METHODS

Clinical and neuropathological data from participants enrolled in a longitudinal study of aging and cognition (n = 649) were analyzed to assess the chronic effects of self-reported head injury.

RESULTS

The effect of self-reported head injury on the clinical state depended on the age at assessment: for a 1-year increase in age, the OR for the transition to clinical mild cognitive impairment (MCI) at the next visit for participants with a history of head injury was 1.21 and 1.34 for the transition from MCI to dementia. Without respect to age, head injury increased the odds of mortality (OR = 1.54). Moreover, it increased the odds of a pathological diagnosis of AD for men (OR = 1.47) but not women (OR = 1.18). Men with a head injury had higher mean amyloid plaque counts in the neocortex and entorhinal cortex than men without.

CONCLUSIONS

Self-reported head injury is associated with earlier onset, increased risk of cognitive impairment and dementia, increased risk of mortality, and AD-type pathological changes.

Cognitive and social lifestyle: links with neuropathology and cognition in late life

Many studies report an association of cognitive and social experiential factors and related traits with dementia risk. Further, many clinical-pathologic studies find a poor correspondence between levels of neuropathology and the presence of dementia and level of cognitive impairment. The poor correspondence suggests that other factors contribute to the maintenance or loss of cognitive function, with factors associated with the maintenance of function referred to as neural or cognitive reserve. This has led investigators to examine the associations of cognitive and social experiential factors with neuropathology as a first step in disentangling the complex associations between these experiential risk factors, neuropathology, and cognitive impairment. Despite the consistent associations of a range of cognitive and social lifestyle factors with cognitive decline and dementia risk, the extant clinical-pathologic data find only a single factor from one cohort, linguistic ability, related to AD pathology. Other factors, including education, harm avoidance, and emotional neglect, are associated with cerebrovascular disease. Overall, the associations are weak. Some factors, such as education, social networks, and purpose in life, modify the relation of neuropathology to cognition. Finally, some factors such as cognitive activity appear to bypass known pathologies altogether suggesting a more direct association with biologic indices that promote person-specific differences in reserve and resilience. Future work will first need to replicate findings across more studies to ensure the veracity of the existing data. Second, effort is needed to identify the molecular substrates of neural reserve as potential mediators of the association of lifestyle factors with cognition.

Lower extremity function trajectories in the African American Health Cohort

BACKGROUND

We addressed two understudied issues in estimating lower extremity functional trajectories in older adults-incorporating the effect of mortality and evaluating heterogeneity among African Americans.

METHODS

Data were taken from the 998 participants in the African American Health cohort. A highly reliable and valid 8-item lower extremity function scale was used at baseline and at the 1-, 2-, 3-, 4-, 7-, and 9-year follow-up interviews. Semiparametric (ie, discrete) group-based mixture modeling identified the trajectories, and multinomial logistic regression identified risk factors for differential trajectory groups.

RESULTS

When treating mortality as informative censoring, six discrete trajectories were observed with 45% of the participants belonging to three stable trajectories (good, fair, or poor function), and the remainder belonging to three declining trajectories (very high function with minimal improvement then minimal decline, very good function with a slow and modest decline, and very good function with a large and quick decline).

CONCLUSION

Substantial heterogeneity in lower extremity function trajectories exists in the African American Health cohort, after appropriately treating mortality as informative censoring.

Adjusting for mortality when identifying risk factors for transitions to mild cognitive impairment and dementia

Risk factors for mild cognitive impairment (MCI) and dementia are often investigated without accounting for the competing risk of mortality, which can bias results and lead to spurious conclusions, particularly regarding protective factors. Here, we apply a semi-Markov modeling approach to 531 participants in the University of Kentucky Biologically Resilient Adults in Neurological Studies (BRAiNS) longitudinal cohort, over one-third of whom died without transitioning to a cognitively impaired clinical state. A semi-Markov approach enables a statistical study of clinical state transitions while accounting for the competing risk of death and facilitates insights into both the odds that a risk factor will affect clinical transitions as well as the age at which the transition to MCI or dementia will occur. Risk factors assessed in the current study were identified by matching those reported in the literature with the data elements collected on participants. The presence of Type II diabetes at baseline shortens the time it takes cognitively intact individuals to transition to MCI by seven years on average while use of estrogen replacement therapy at enrollment (baseline) decreases the time required to convert from MCI to dementia by 1.5 years. Finally, smoking and being overweight do not promote transitions to impaired states but instead hasten death without a dementia. In contrast, conventional statistical analyses based on Cox proportional hazards models fail to recognize diabetes as a risk, show that being overweight increases the risk of clinical MCI, and that high blood pressure at baseline increases the risk of a dementia.

Predictors of Nursing Home Placement from Assisted Living Settings in Canada

We sought to estimate the incidence of long-term care (LTC) placement and to identify resident- and facility-level predictors of placement among older residents of designated assisted living (AL) facilities in Alberta, Canada. Included were 1,086 AL residents from 59 facilities. Research nurses completed interRAI-AL resident assessments and interviewed family caregivers and administrators. Predictors of placement were identified with multivariable Cox proportional hazards models. The cumulative incidence of LTC admission was 18.3 per cent by 12 months. Significantly increased risk for placement was evident for older residents and those with poor social relationships, little involvement in activities, cognitive and/or functional impairment, health instability, recent falls and hospitalizations/emergency department visits, and severe bladder incontinence. Residents from larger facilities, with an LPN and/or RN on-site 24/7 and with an affiliated primary care physician, showed lower risk of placement. Our findings highlight clinical and policy areas where targeted interventions may delay LTC admissions.

C57BL/6 neuromuscular healthspan scoring system

Developing a scoring system based on physiological and functional measurements is critical to test the efficacy of potential interventions for sarcopenia and frailty in aging animal models; therefore, the aim of this study was to develop a neuromuscular healthspan scoring system (NMHSS). We examined three ages of male C57BL/6 mice: adults (6-7 months old, 100% survival), old (24-26 months old, 75% survival), and elderly group (>28 months old, ≤50% survival)-as well as mice along this age continuum. Functional performance (as determined by the rotarod and inverted-cling grip test) and in vitro muscle contractility were the determinants. A raw score was derived for each determinant, and the NMHSS was then derived as the sum of the individual determinant scores. In comparison with individual determinants, the NMHSS reduced the effect of individual variability within age groups, thus potentially providing an enhanced ability to detect treatment effects in future studies.

Activity of daily living trajectories surrounding acute hospitalization of long-stay nursing home residents

OBJECTIVES

To explore patterns of change in nursing home (NH) residents' activities of daily living (ADLs), particularly surrounding acute hospital stays.

DESIGN

Longitudinal study using Medicare and Minimum Data Set (MDS) assessments.

SETTING

National sample of long-stay NH residents.

PARTICIPANTS

NH residents who were hospitalized for the seven most-common inpatient diagnoses (N = 40,128). Each hospital admission was at least 90 days after any prior hospitalization and had at least two preceding MDS assessments.

MEASUREMENTS

The MDS ADL long-form score, a simple sum of seven self-care variables coded from 0 (independent) to 4 (totally dependent) was used to indicate resident ADL function. Scores ranged from 0 to 28, with higher scores indicating greater impairment. A linear mixed model describing ADL trajectories was jointly estimated with time-to-event models for mortality and hospital readmission.

RESULTS

Before hospitalization, the most common trajectory was stable (53.7%), with 27.5% of residents worsening and 18.8% improving. ADL function after hospital discharge was most often characterized as stable (43.1%) or worsening (39.2%). Mortality (20.3%) was higher for those with worsening prehospital ADL function (28.9%) than for those with stable (19.1%) or improving (11.3%) trajectories. Hospital diagnosis was associated with amount of ADL worsening and rate of subsequent ADL change. Most residents with the best initial function continued to worsen after hospital discharge. Cognitive impairment was associated with poorer ADL function and accelerated worsening of ADLs.

CONCLUSION

For many long-stay NH residents, substantial and sustained ADL worsening accompanies acute hospitalization, so acute hospitalization presents an opportunity to revisit care goals; the results of the current study can help inform decision-making.

Effects of self-reported osteoarthritis on physical performance: a longitudinal study with a 10-year follow-up

BACKGROUND AND AIMS

Osteoarthritis (OA) of the knee or hip is associated with limitations in activities of daily life. There are only a few long-term studies on how knee or hip OA affects the course of physical performance. The aim of this study was to investigate the effects of knee or hip OA on physical performance during a follow-up period of 10 years.

METHODS

Participants in the Longitudinal Aging Study Amsterdam with self-reported hip or knee OA (N = 155) were prospectively followed for 10 years on 4 occasions from the onset of OA and compared to participants without OA (N = 1004). Physical performance was tested with walk, chair stand and balance tests. Scores for each test were summed to a total performance score (range 0-12), higher scores indicating better performance. Generalized estimating equations were used to analyze differences between participants with and without OA, unadjusted as well as adjusted for confounders.

RESULTS

There was a significant interaction between OA and sex (P = 0.068). Both in men and women, total performance was lower for participants with OA, with greater differences in men. Chair stand and walking performance (P < 0.05), but not balance, were lower in participants with OA. After adjustment for confounders, these associations remained significant in men but not in women. Additional analyses correcting for follow-up duration and attrition showed lower performance scores for men and women with OA.

CONCLUSIONS

OA negatively affected physical performance 3-6 years after it was first reported. Performance in men with OA was more affected than in women.

Dementia case management and risk of long-term care placement: a systematic review and meta-analysis

OBJECTIVES

The objective of our study is to evaluate the effectiveness of dementia case management compared with usual care on reducing long-term care placement, hospitalization, and emergency department visits for adult patients with dementia. We also sought to evaluate the effectiveness of this intervention on delaying time to long-term care placement and hospitalization.

METHODS

We searched electronic databases supplemented by bibliographies and conference proceedings for randomized controlled trials testing the effectiveness of dementia case management in reducing resource utilization in a population of caregiver-care recipient dyads living in the community. We meta-analyzed the risk ratio (RR) and weighted mean differences of long-term care placement and the RR of hospital admissions. Pooled estimates were further stratified by study characteristics and measures of study quality.

RESULTS

Seventeen studies were included in the meta-analysis. The overall pooled RR of long-term care placement was 0.94 (95% confidence interval [0.85, 1.03]; p = 0.227) for dementia case management compared with usual care. Stratification by follow-up duration indicated a statistically significant reduction in risk of long-term care placement when follow-up duration was less than 18 months (RR 0.61, 95% confidence interval [0.41, 0.91], p = 0.015). There was no effect of dementia case management compared with usual care for the other outcomes.

CONCLUSION

Dementia case management demonstrated a short-term positive effect on reducing the risk of long-term care placement among older people with dementia residing in the community. However, other sources of resource utilization and more extended effects of dementia case management on risk of long-term care placement warrant further investigation.

Results differ by applying distinctive multiple imputation approaches on the longitudinal cardiovascular health study data

BACKGROUND/STUDY CONTEXT: The objective of this study was to examine sequential and simultaneous approaches to multiple imputation of missing data in a longitudinal data set where losses due to death were common.

METHODS

Comparison of results from analyses and simulations of time to incident difficulty of activities of daily living (ADL) in the Cardiovascular Health Study when missing data were imputed simultaneously or sequentially.

RESULTS

Results differed with imputation methods. The largest proportional differences in 12 risk factor parameter estimates were heart failure by 106%, social support by 33%, and arthritis by 27%.

CONCLUSION

Decedents' final characteristics were influential on future imputations of those with missing values.

Dynamics of functional aging based on latent-class trajectories of activities of daily living

PURPOSE

This study sought to identify and characterize major patterns of functional aging based on activities of daily living (ADL).

METHODS

We followed 754 community-living adults aged 70 years or older monthly for ADLs, instrumental ADLs, hospitalization and restricted activity over 10 years. A generalized growth mixture model was used to identify trajectories of ADL disability across seven 18-month intervals. Cumulative burdens of disability and morbidity from different trajectories were examined using a generalized estimating equation Poisson model.

RESULTS

Five distinct trajectories emerged. The predominant trajectory maintained ADL independence, with membership probability being 61.6%. The remaining trajectories either stayed at low (1 or 2 ADLs, 13.6%) or high (3 or 4 ADLs, 7.0%) levels of disability or declined gradually toward low (11.2%) or high (6.5%) disability. The independent trajectory was associated with the lowest burdens of disability and morbidity and a decreasing time trend of restricted activity, whereas the high disability trajectory demonstrated opposite trends. About 31% of the cohort remained in the same trajectory throughout the follow-up period.

CONCLUSIONS

The course of functional aging is heterogeneous and dynamic. Although most older adults maintain functional autonomy, some may experience persistent disability or progress toward severe disability with substantial morbidity.

The effect of stability and change in health behaviors on trajectories of body mass index in older Americans: a 14-year longitudinal study

BACKGROUND

Obesity is increasingly prevalent among older adults, yet little is known about the impact of health behaviors on the trajectories of body weight in this age group.

METHODS

We examined the effect of time-varying smoking, physical activity (PA), alcohol use, and changes thereof, on the 14-year (1992-2006) trajectory of body- mass index (BMI) in a cohort of 10,314 older adults from the Health and Retirements Study, aged 51-61 years at baseline. Hierarchical linear modeling (HLM) quantifies the effect of smoking, PA, and alcohol use (user status, initiation and cessation) on intercept and rate-of-change in BMI trajectory, and tests for variations in the strength of association between each behavior and BMI.

RESULTS

Over 14 years (82,512 observations), BMI increased approximated by a quadratic function. Smoking and PA (user status and initiation) were associated with significantly lower BMI trajectories over time. Cessation of smoking and PA resulted in higher BMI trajectories over time. The weight-gaining effect of smoking cessation increased, while the strength of association between BMI trajectories and PA or alcohol use were constant over time. Socio-economic and health status differences explained the effects of alcohol use on BMI trajectory.

CONCLUSIONS

In older adults, smoking and PA, and changes thereof, vary in their long-term effect on trajectories of BMI. Barring increases in PA levels, older smokers who quit today are expected to gain significantly more weight than two decades ago. This knowledge is essential for the design of smoking cessation, physical activityPA, and weight-control interventions in older adults.

Older adults' spirituality and life satisfaction: a longitudinal test of social support and sense of coherence as mediating mechanisms

Spirituality is proposed to be a component of successful ageing and has been shown to predict wellbeing in old age. There has been conceptual discussion of possible mechanisms that link spirituality with positive psychological functioning in older adults, but few empirical examinations of these linking mechanisms over time. The current study examined the role of Antonovsky's Sense of Coherence (SOC) and social support in mediating the effects of spirituality on life satisfaction in older participants over a four-year period. The study used a cross-lagged panel analysis to evaluate longitudinal mediation within a path analysis framework. Results showed that the meaningfulness dimension of SOC mediated the influence of spirituality on life satisfaction over time, suggesting that spirituality may influence older adults' experience and perception of life events, leading to a more positive appraisal of these events as meaningful. Social support was not found to mediate the pathway between spirituality and life satisfaction. This study may be the first to examine the link between spirituality, sense of coherence, social support and wellbeing, as measured by life satisfaction, using longitudinal data from a community sample of older adults. The study provides evidence for the positive role of spirituality in the lives of older people. This is an area that requires further examination in models of successful ageing.

Subjective social status and functional decline in older adults

BACKGROUND

It is unknown whether subjective assessment of social status predicts health outcomes in older adults.

OBJECTIVE

To describe the relationship between subjective social status and functional decline in older adults.

DESIGN

Longitudinal cohort study.

SETTING

The Health and Retirement Study, a nationally representative survey of community-dwelling older adults (2004-2008).

PARTICIPANTS

Two thousand five hundred and twenty-three community-dwelling older adults.

MAIN MEASURES

Self-report of social status (SSS), categorized into three groups, reported by participants who marked a 10-rung ladder to represent where they stand in society. Four-year functional decline (new difficulty in any of five activities of daily living, mobility decline and/or death)

KEY RESULTS

Mean age was 64; 46% were male, 85% were white. At baseline, lower SSS was associated with being younger, unmarried, of nonwhite race/ethnicity, higher rates of chronic medical conditions and ADL impairment (P < 0.01). Over 4 years, 50% in the lowest SSS group declined in function, compared to the middle and highest groups (28% and 26%), P-trend <0.001. Those in the lowest rungs of SSS were at increased risk of 4-year functional decline (unadjusted RR = 1.91, CI 1.-9-2.46). The relationship between a subjective belief that one is worse off than others and functional decline persisted after serial adjustment for demographics, objective SES measures, and baseline health and functional status (RR 1.36, CI 1.08-1.73).

CONCLUSIONS

In older adults, the belief that one is in the lowest rungs of social status is a measure of socioeconomic distress and of significant risk for functional decline. These findings suggest that self-report of low subjective social status may give clinicians additional information about which older adults are at high risk for future functional decline.

Subjective social status and functional decline in older adults

BACKGROUND

It is unknown whether subjective assessment of social status predicts health outcomes in older adults.

OBJECTIVE

To describe the relationship between subjective social status and functional decline in older adults.

DESIGN

Longitudinal cohort study.

SETTING

The Health and Retirement Study, a nationally representative survey of community-dwelling older adults (2004-2008).

PARTICIPANTS

Two thousand five hundred and twenty-three community-dwelling older adults.

MAIN MEASURES

Self-report of social status (SSS), categorized into three groups, reported by participants who marked a 10-rung ladder to represent where they stand in society. Four-year functional decline (new difficulty in any of five activities of daily living, mobility decline and/or death)

KEY RESULTS

Mean age was 64; 46% were male, 85% were white. At baseline, lower SSS was associated with being younger, unmarried, of nonwhite race/ethnicity, higher rates of chronic medical conditions and ADL impairment (P < 0.01). Over 4 years, 50% in the lowest SSS group declined in function, compared to the middle and highest groups (28% and 26%), P-trend <0.001. Those in the lowest rungs of SSS were at increased risk of 4-year functional decline (unadjusted RR = 1.91, CI 1.-9-2.46). The relationship between a subjective belief that one is worse off than others and functional decline persisted after serial adjustment for demographics, objective SES measures, and baseline health and functional status (RR 1.36, CI 1.08-1.73).

CONCLUSIONS

In older adults, the belief that one is in the lowest rungs of social status is a measure of socioeconomic distress and of significant risk for functional decline. These findings suggest that self-report of low subjective social status may give clinicians additional information about which older adults are at high risk for future functional decline.