Introduction to a Supplement on Population Level Trends in Dementia: Causes, Disparities, and Projections

Socioeconomic and medical determinants of state-level subjective cognitive decline in the United States

INTRODUCTION

It is important to understand the socioeconomic and medical determinants of subjective cognitive decline (SCD) at a population level in the United States.

METHODS

The primary outcomes are state-level rates of SCD and SCD-related functional impairment in adults aged ≥ 45, both measured in the Behavioral Risk Factor Surveillance System from 2016 to 2022. The exposures are state-level rates of poverty, unemployment, homelessness, college education, racial and ethnic minorities, uninsurance, smoking, hypertension, diabetes, and obesity as well as household income and physician density.

RESULTS

The strongest state-level associations with rates of SCD were the prevalence of diabetes (rho = 0.64), hypertension (rho = 0.59), and poverty (rho = 0.58; all p < 0.001), and with SCD-related functional impairment were prevalence of poverty (rho = 0.71), diabetes (rho = 0.68), and hypertension (rho = 0.53; all p < 0.001).

DISCUSSION

This study highlights critical links between SCD and socioeconomic and medical determinants in adults aged ≥ 45 in the United States, including the prevalence of poverty, diabetes, and hypertension.

HIGHLIGHTS

State-level analysis reveals socioeconomic and medical risk factors for subjective cognitive decline (SCD) at a population level. The prevalence of poverty is a critical contributor to the state-level prevalence of SCD. The prevalence of diabetes and hypertension are also strong state-level determinants of SCD. Addressing the burden of cognitive decline at the population level necessitates targeting socioeconomic and medical factors.

Projecting the Likely Impact of COVID-19 Infections on the Prevalence of Dementia in the United States

Background

The association between COVID-19 infection and the onset of dementia among adults 65 years and older has the potential to increase the burden of dementia worldwide significantly. Our research, which focuses on understanding the likely increase in the burden of dementia due to COVID-19 infection in the USA, has crucial public policy implications. By providing these insights, we aim to empower policymakers, healthcare professionals, researchers, and public health officials to make informed decisions and plan for the future.

Objective

Project the prevalence of dementia in the United States while accounting for the impact of COVID-19 infection on the onset of dementia.

Methods

A dynamic multi-state population model was developed. The model was initialized with USA demographic data and estimates of age, gender, and race-specific transition rates from the Health and Retirement Study (HRS).

Results

The projected increase in the burden of dementia among Americans 65 years and older is a staggering 14.838 million by 2050. However, due to the COVID-19 pandemic, we anticipate an additional 265,000 to 677,000 older adults 65 years and older will be affected by dementia. This will escalate the burden of dementia to a potential 15.103 million to 15.515 million by 2050, a significant human toll that we must be prepared for.

Conclusions

The projected dementia numbers underscore the urgent need for policy and intervention in social care services and healthcare needs planning. This includes providing robust support systems for caregivers and ensuring the healthcare staff is adequately trained to meet the healthcare needs of dementia patients and their families.

Evaluating a brief intervention for mealtime difficulty on older adults with dementia

AIMS AND OBJECTIVE

To test a spaced retrieval intervention using spaced retrieval to alleviate mealtime difficulties in older people with dementia.

DESIGN

A single-case study design.

SETTING

Nursing Homes in North Central England, United Kingdom.

PARTICIPANTS

Older people with Alzheimer's disease.

METHODS

A single-case study using an ABA design was used. Data were collected using the Edinburgh Feeding Evaluation in Dementia scale, Mini Nutritional Assessment, and Body Mass Index before intervention, postintervention and following 3 months of postintervention. Realist evaluation was used to identify for which participants the intervention was effective, and an economic evaluation was also carried out.

FINDING

Of 15 participants who entered the study, eight completed all phases of the study. A mean 104.4 h were needed to deliver the intervention. The number of sessions required ranged from 90-222. The length of time each participant retained information (for all sessions) ranged from 13-28 min. Participants had most difficulty with: "putting food into mouth and chewing it"; "realizing it was mealtime"; and "eating a whole meal continuously." A reduction in the difficulty with mealtimes occurred between phase A1-A2 for most participants. Six participants maintained this in phase A3. Similar patterns were evident for nutritional scores. For most participants, the effect size of the intervention was moderate or large.

CONCLUSIONS

Spaced retrieval is useful in reducing mealtime difficulties in older participants with dementia. While the results of this study are promising, further large and multicentre trials are needed to explore the effectiveness of the intervention in diverse populations.

Interactions Between the Aging Gut Microbiome and Common Geriatric Giants: Polypharmacy, Frailty, and Dementia

The gut microbiome has pervasive bidirectional relationships with pharmacotherapy, chronic disease, and physical and cognitive function. We conducted a narrative review of the current literature to examine the relationships between the gut microbiome, medication use, sarcopenia and frailty, and cognitive impairment. Data from in vitro experiments, in vivo experiments in invertebrates and complex organisms, and humans indicate associations between the gut microbiome and geriatric syndromes. Better understanding of the direct and indirect roles of the microbiome may inform future prevention and management of geriatric syndromes.

Social engagement and cognitive function among middle-aged and older adults: gender-specific findings from the Korean longitudinal study of aging (2008-2018)

Recent findings suggest that social disengagement in later life may result in cognitive decline and increase risk of Alzheimer’s and related dementias. However, little is known regarding the gender-specific longitudinal association between social engagement and cognition among middle-aged and older adults. Using data from a nationally representative sample of 2707 men and 5196 women from the Korean longitudinal study of aging, we examined the gender-specific association between social activity and cognitive function. Results from the generalized estimating equation model showed that compared to individuals with consistent social engagement (religious, senior center, sport, reunion, voluntary, political), individuals with inconsistent engagement had lower cognitive function. Transitioning from engagement to non-engagement was associated with lower cognitive function among men only. Not being part of a senior center was associated with decreased cognitive function among both genders, while not being part of a religious group was significant for women only. While marital status was a significant predictor of cognitive ability for women, depression was a significant predictor for men. These findings have implications for policy-makers as interventions targeting improved cognitive function among middle-aged and older adults may be more effective when gender-specific predictors are taken into consideration.

Impact of dementia: Health disparities, population trends, care interventions, and economic costs

INTRODUCTION

The dementia experience is not a monolithic phenomenon-and while core elements of dementia are considered universal-people living with dementia experience the disorder differently. Understanding the patterning of Alzheimer's disease and related dementias (ADRD) in the population with regards to incidence, risk factors, impacts on dementia care, and economic costs associated with ADRD can provide clues to target risk and protective factors for all populations as well as addressing health disparities.

METHODS

We discuss information presented at the 2020 National Research Summit on Care, Services, and Supports for Persons with Dementia and Their Caregivers, Theme 1: Impact of Dementia. In this article, we describe select population trends, care interventions, and economic impacts, health disparities and implications for future research from the perspective of our diverse panel comprised of academic stakeholders, and persons living with dementia, and care partners.

RESULTS

Dementia incidence is decreasing yet the advances in population health are uneven. Studies examining the educational, geographic and race/ethnic distribution of ADRD have identified clear disparities. Disparities in health and healthcare may be amplified by significant gaps in the evidence base for pharmacological and non-pharmacological interventions. The economic costs for persons living with dementia and the value of family care partners' time are high, and may persist into future generations.

CONCLUSIONS

Significant research gaps remain. Ensuring that ADRD healthcare services and long-term care services and supports are accessible, affordable, and effective for all segments of our population is essential for health equity. Policy-level interventions are in short supply to redress broad unmet needs and systemic sources of disparities. Whole of society challenges demand research producing whole of society solutions. The urgency, complexity, and scale merit a "whole of government" approach involving collaboration across numerous federal agencies.

Dual Trajectories of Dementia and Social Support in the Mexican-Origin Population

BACKGROUND AND OBJECTIVES

In the next few decades, the number of Mexican American older adults with Alzheimer's disease and related disorders will increase dramatically. Given that this population underutilizes formal care services, the degree of care responsibilities in Mexican American families is likely to increase at the same time. However, little is known about the changing need for assistance with instrumental day-to-day activities and emotional support by long-term patterns of cognitive impairment.

RESEARCH DESIGN AND METHODS

We use 7 waves of the Hispanic Established Populations for the Epidemiologic Studies of the Elderly (1992/1993-2010/2011) and trajectory modeling to describe long-term patterns of perceived emotional and instrumental support, and dementia.

RESULTS

Results revealed 2 latent classes of both emotional and instrumental support trajectories: low and high support. Specifically, those living alone were more likely to belong to the group with low support than to that with high support. Three latent classes for likely dementia were also revealed: likely dementia, increasing impairment, and no impairment. Those living alone were more likely to belong to the increasing impairment and likely dementia groups. The dual trajectory of emotional and instrumental support with likely dementia revealed that the probability of belonging to the low-support group was highest for those with increasing impairment.

DISCUSSION AND IMPLICATIONS

These findings highlight the risk and vulnerability of those who live alone concerning perceived social support and dementia. Implications of the findings for the potential dependency burden on Latino caregivers are discussed.

Trends in Physical and Cognitive Performance Among Community-Dwelling Older Adults in Switzerland

BACKGROUND

With population aging, a key question is whether new cohorts of older people are in better health than previous ones. This study aimed to compare the physical and cognitive performance of community-dwelling older adults assessed at similar age in 2005, 2010, and 2015.

METHODS

This repeated cross-sectional analysis used data from the Lausanne cohort 65+, a three random sample population-based study. Performance of participants aged 66-71 years in 2005 (N = 1,309), 2010 (N = 1,253), and 2015 (N = 1,328) was compared using a battery of six physical and four cognitive tests. Analyses included tests for trend across samples and multivariable linear regression models.

RESULTS

Adjusted performance in all four timed physical tests (gait speed, Timed Up-and-Go, five times chair stand, and Moberg Picking-Up) improved across samples from 2005 to 2015, by +12.7% (95% confidence interval {CI} +10.5%; +14.9%) to +20.4% (95% CI +17.7%; +23.0%) in females, and by +10.6% (95% CI +8.7%; +12.4%) to +16.7% (95% CI +13.4%; +20.0%) in males. In contrast, grip strength and balance did not improve across samples. Adjusted cognitive performance showed no change in the Trail Making Test, but worsened significantly across samples for the Mini-Mental State Examination, verbal fluency, and the clock drawing test in both females (-1.9% [95% CI -2.7%; -1.1%] to -6.7% [95% CI -8.9%; -4.6%]) and males (-2.5% [95% CI -3.4%; -1.6%] to -8.0% [95% CI -11.1%; -4.9%]).

CONCLUSIONS

Over the last decade, performance of adults aged 66-71 years improved significantly in timed physical tests but worsened in most cognitive measures among later-born samples.

Cognitively Intact and Happy Life Expectancy in the United States

OBJECTIVES

We examined the number of years to be lived with and without cognitive impairment and with high self-assessed quality of life (i.e., happiness) among a nationally representative sample of Americans aged 65 years and older. Two key questions are addressed: Can people have a high quality of life despite being cognitively impaired? Which is longer: happy life expectancy or cognitively intact life expectancy?

METHOD

Data from nine waves of the Health and Retirement Study (1998-2014) were used to estimate transition probabilities into and out of cognitively intact/impaired-un/happy states, as well as to death. Recently extended Bayesian multistate life table methods were used to estimate age-specific cognitively intact and happy life expectancy net of sex, race/ethnicity, education, and birth cohort.

RESULTS

Happiness and cognitive impairment were shown to coexist in both the gross cross-tabulated data and in the life tables. Happy life expectancy is approximately 25% longer than cognitively intact life expectancy at age 65 years, and by age 85, happy life expectancy is roughly double cognitively intact life expectancy, on average.

DISCUSSION

Lack of cognitive impairment is not a necessary condition for happiness. In other words, people can have a high quality of life despite being cognitively impaired.

A New Look at Cohort Trend and Underlying Mechanisms in Cognitive Functioning

OBJECTIVES

The prevalence of dementia in the United States seems to have declined over the last few decades. We investigate trends and their underlying mechanisms in cognitive functioning (CF) across 7 decades of birth cohorts from the Greatest Generation to Baby Boomers.

METHODS

Data come from 30,191 participants of the 1996-2014 Health and Retirement Study. CF is measured as a summary score on a 35-point cognitive battery of items. We use generalized linear models to examine the trends in CF and explanatory variables across birth cohorts. Then, Karlson-Holm-Breen decomposition method is used to evaluate the contribution of each explanatory variable to the trend of CF.

RESULTS

CF has been improving from the Greatest Generation to Late Children of Depression and War Babies, but then significantly declines since the Early-Baby Boomers and continues into Mid-Baby Boomers. This pattern is observed universally across genders, race/ethnicities, education groups, occupations, income, and wealth quartiles. The worsening CF among Baby Boomers does not originate from childhood conditions, adult education, or occupation. It can be attributed to lower household wealth, lower likelihood of marriage, higher levels of loneliness, depression and psychiatric problems, and more cardiovascular risk factors (e.g., obesity, physical inactivity, hypertension, stroke, diabetes, and heart disease).

DISCUSSION

The worsening CF among Baby Boomers may potentially reverse past favorable trends in dementia as they reach older ages and cognitive impairment becomes more common if no effective interventions and policy responses are in place.

Who uses residential aged care now, how has it changed and what does it mean for the future?

ObjectiveThis paper presents past trends in resident characteristics and usage patterns in residential aged care and explores implications for the future. MethodsTime series analyses were undertaken of national aged care administrative datasets and the Australian Bureau of Statistics Surveys of Disability, Ageing and Carers. ResultsAlthough the number of people in residential care has continued to increase, resident profiles have changed as a result of higher growth rates in the number of men and of people aged 65–74 years and 90 years and over, and a decline in the number of women aged 75–89 years. Relative to population size, usage rates are declining across all age groups, the average length of stay is shortening, and dependency levels appear to be rising. ConclusionChanging trends in residential aged care use, when combined with key trends in the broader population of older Australians, offer useful insights in planning for the future. What is known about the topic?Trends in the changing characteristics of permanent aged care residents and patterns of use of Australian residential aged care have received sparse attention in scholarly journals. Government reports and databases contain useful statistics, but they do not provide a coherent analysis and interpretation of the implications of these trends or situate them in broader population patterns. What does this paper add?The analyses in this paper demonstrate patterns of change and continuity in the use of residential care over the past decade, and locate those changes in the context of broader trends in the ageing population. Together, this provides useful insights into current and likely future trends, as well as a basis for imagining an improved residential aged care system in the future. What are the implications for practitioners?These analyses illustrate how data on aged care services, demographic trends and disease patterns can be used to consider the challenges that have affected our residential aged care system in the past and how that may be addressed in the future.