Racial and ethnic differences in trends in dementia prevalence and risk factors in the United States

Learning ratio performance on a brief visual learning and memory test moderates cognitive training gains in Double Decision task in healthy older adults

Cognitive training using a visual speed-of-processing task, called the Useful Field of View (UFOV) task, reduced dementia risk and reduced decline in activities of daily living at a 10-year follow-up in older adults. However, there was variability in the achievement of cognitive gains after cognitive training across studies, suggesting moderating factors. Learning trials of visual and verbal learning tasks recruit similar cognitive abilities and have overlapping neural correlates with speed-of-processing/working memory tasks and therefore could serve as potential moderators of cognitive training gains. This study explored the association between the Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) learning with a commercial UFOV task called Double Decision. Through a secondary analysis of a clinical trial, we assessed the moderation of HVLT-R and BVMT-R learning on Double Decision improvement after a 3-month speed-of-processing/attention and working memory cognitive training intervention in a sample of 75 cognitively healthy older adults. Multiple linear regressions showed that better baseline Double Decision performance was significantly associated with better BVMT-R learning (β =  - .303). This association was not significant for HVLT-R learning (β =  - .142). Moderation analysis showed that those with poorer BVMT-R learning improved the most on the Double Decision task after cognitive training. This suggests that healthy older adults who perform below expectations on cognitive tasks related to the training task may show the greatest training gains. Future cognitive training research studying visual speed-of-processing interventions should account for differing levels of visuospatial learning at baseline, as this could impact the magnitude of training outcomes and efficacy of the intervention.

Racial and ethnic differences in the risk of dementia diagnosis under hypothetical blood pressure-lowering interventions: The Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

Substantial racial and ethnic disparities in hypertension and dementia exist in the United States. We evaluated the effect of maintaining systolic blood pressure (SBP) below clinical thresholds on dementia incidence.

METHODS

We included 6806 Multi-Ethnic Study of Atherosclerosis participants (44 to 84 years old). We implemented the parametric g-formula to simulate the hypothetical interventions to reduce SBP below 120 and 140 mmHg over time, accounting for time-varying confounding. We estimated risk ratios (RRs) and risk differences for dementia incidence at 19 years.

RESULTS

The RRs (95% confidence intervals [CIs]) comparing an intervention reducing SBP below 120 mmHg to no intervention were 0.93 (0.87 to 0.99) for total sample, 0.95 (0.88 to 1.02) for White, 0.90 (0.79 to 1.02) for Black, 0.90 (0.78 to 1.05) for Latino, and 1.16 (0.83 to 1.55) for Chinese American participants. Results for lowering SBP below 140 mmHg and with death as competing event were attenuated.

DISCUSSION

The reduction of SBP below 120 mmHg over time has modest effects on reducing dementia incidence. More work is needed to understand the heterogeneity across racial and ethnic groups.

HIGHLIGHTS

There is a potential beneficial effect in lowering SBP to reduce the risk of dementia, which may vary by race and ethnicity. The percentage of participants who would need intervention on blood pressure to meet clinical thresholds is greater for Black and Latino communities. Results are sensitive to the way that death is specified in the research question and analysis.

Heterogeneous treatment effects of sodium-glucose cotransporter 2 inhibitors on risk of dementia in people with type 2 diabetes: A population-based cohort study

INTRODUCTION

Sodium-glucose cotransporter 2 (SGLT2) inhibitors exhibit potential benefits in reducing dementia risk, yet the optimal beneficiary subgroups remain uncertain.

METHODS

Individuals with type 2 diabetes (T2D) initiating either SGLT2 inhibitor or sulfonylurea were identified from OneFlorida+ Clinical Research Network (2016-2022). A doubly robust learning was deployed to estimate risk difference (RD) and 95% confidence interval (CI) of all-cause dementia.

RESULTS

Among 35,458 individuals with T2D, 1.8% in the SGLT2 inhibitor group and 4.7% in the sulfonylurea group developed all-cause dementia over a 3.2-year follow-up, yielding a lower risk for SGLT2 inhibitors (RD, -2.5%; 95% CI, -3.0% to -2.1%). Hispanic ethnicity and chronic kidney disease were identified as the two important variables to define four subgroups in which RD ranged from -4.3% (-5.5 to -3.2) to -0.9% (-1.9 to 0.2).

DISCUSSION

Compared to sulfonylureas, SGLT2 inhibitors were associated with a reduced risk of all-cause dementia, but the association varied among different subgroups.

HIGHLIGHTS

New users of sodium-glucose cotransporter 2 (SGLT2) inhibitors were significantly associated with a lower risk of all-cause dementia as compared to those of sulfonylureas. The association varied among different subgroups defined by Hispanic ethnicity and chronic kidney disease. A significantly lower risk of Alzheimer's disease and vascular dementia was observed among new users of SGLT2 inhibitors compared to those of sulfonylureas.

Social determinants of health but not global genetic ancestry predict dementia prevalence in Latin America

INTRODUCTION

Leveraging the nonmonolithic structure of Latin America, which represents a large variability in social determinants of health (SDoH) and high levels of genetic admixture, we aim to evaluate the relative contributions of SDoH and genetic ancestry in predicting dementia prevalence in Latin American populations.

METHODS

Community-dwelling participants aged 65 and older (N = 3808) from Cuba, Dominican Republic, Mexico, and Peru completed the 10/66 protocol assessments. Dementia was diagnosed using the cross-culturally validated 10/66 algorithm. Multivariate linear regression models adjusted for SDoH were used in the main analysis. This study used cross-sectional data from the 1066 population-based study.

RESULTS

Individuals with higher proportions of Native American (>70%) and African American (>70%) ancestry were more likely to exhibit factors contributing to worse SDoH, such as lower educational levels (p < 0.001), lower socioeconomic status (p < 0.001), and higher frequency of vascular risk factors (p < 0.001). After adjusting for measures of SDoH, there was no association between ancestry proportion and dementia probability, and ancestry proportions no longer significantly accounted for the variance in cognitive performance (African predominant p = 0.31 [-0.19, 0.59] and Native predominant p = 0.74 [-0.24, 0.33]).

DISCUSSION

The findings suggest that social and environmental factors play a more crucial role than genetic ancestry in predicting dementia prevalence in Latin American populations. This underscores the need for public health strategies and policies that address these social determinants to effectively reduce dementia risk in these communities.

HIGHLIGHTS

Countries in Latin America express a large variability in social determinants of health and levels of admixture. After adjustment for downstream societal factors linked to SDoH, genetic ancestry shows no link to dementia. Population ancestry profiles alone do not influence cognitive performance. SDoH are key drivers of racial disparities in dementia and cognitive performance.

Performance of the Modified Caregiver Strain Index in a Sample of Black and White Persons Living With Dementia and Their Caregivers

BACKGROUND AND OBJECTIVES

This study examined the performance of the Modified Caregiver Strain Index (MCSI) in a sample of Black and White caregivers of persons living with dementia.

RESEARCH DESIGN AND METHODS

Data on 153 dyads enrolled in the Care Ecosystem dementia care management program were analyzed, including sociodemographic variables, dementia severity, and caregiver burden and wellbeing. Factor structure, item-response patterns, and concurrent validity were assessed across racial groups.

RESULTS

Differences between Black and White caregivers included gender, dyad relation, and socioeconomic disadvantage. Factor structure and item loadings varied by racial cohort, with parameters supporting a 3-factor model. For Black caregivers, finances and work, emotional and physical strain, and family and personal adjustment items loaded together on individual factors. For White caregivers physical and emotional strain items loaded on separate factors, although personal and family adjustment items loaded with work and financial strain items. Item-level analysis revealed differences between groups, with Black caregivers endorsing physical strain to a greater degree (p = .003). Total MCSI scores were positively correlated with concurrent measures like the PHQ-9 (White: r = 0.67, Black: r = 0.54) and the GAD-2 (White: r = 0.47, Black: r = 0.4), and negatively correlated with self-efficacy ratings (White: r = -0.54, Black: r = -0.55), with a p < .001 for all validity analysis.

DISCUSSION AND IMPLICATIONS

The MCSI displayed acceptable statistical performance for Black and White caregivers of persons living with dementia and displayed a factor structure sensitive to cultural variations of the construct. Researchers results highlight the inherent complexity and the relevance of selecting inclusive measures to appropriately serve diverse populations.

Social Environment, Lifestyle, and Genetic Predisposition With Dementia Risk: A Long-Term Longitudinal Study Among Older Adults

BACKGROUND

The role of social environment, that is, the aggregate effect of social determinants of health (SDOHs), in determining dementia is unclear.

METHODS

We developed a novel polysocial risk score for dementia based on 19 SDOH among 5 199 participants in the Health and Retirement Study, United States, to measure the social environmental risk. We used a survival analysis approach to assess the association between social environment and dementia risk in 2006-2020. We further studied the interaction between social environment and lifestyles, and explored racial disparities.

RESULTS

The study participants (mean age = 73.4 years, SD = 8.3; 58.0% female; 11.6% African American) were followed up for an average of 6.2 years, and 1 089 participants developed dementia. Every 1-point increase in the polysocial risk score (ranging from 0 to 10) was associated with a 21.6% higher risk (adjusted hazard ratio [aHR] = 1.21, 95% confidence intervals [95% CI] = 1.15-1.26) of developing dementia, other things being equal. Among participants with high social environmental risk, regular exercise and moderate drinking were associated with a 43%-60% lower risk of developing dementia (p < .001). In addition, African Americans were 1.3 times (aHR = 2.28, 95% CI = 1.96-2.66) more likely to develop dementia than European Americans, other things being equal.

CONCLUSION

An adverse social environment is linked to higher dementia risk, but healthy lifestyles can partially offset the increased social environmental risk. The polysocial risk score can complement the existing risk tools to identify high-risk older populations, and guide the design of targeted social environmental interventions, particularly focusing on improving the companionship of the older people, to prevent dementia.

Perceptions about dementia clinical trials among underrepresented populations: A nationally representative survey of U.S. dementia caregivers

Background

The research community has historically failed to enroll diverse groups of participants in dementia clinical trials. A unique aspect of dementia care research is the requirement of a study partner, who can attest to the care recipient's clinical and functional capacity. The aim of this study is to assess racial and ethnic differences and the importance of various trial considerations among dementia caregivers, in their decision to participate in clinical research as study partners.

Method

We embedded a vignette about a hypothetical dementia clinical trial in a nationally representative survey of U.S. dementia caregivers, oversampling non-Hispanic Black and Hispanic caregivers. Dementia caregivers were asked about their willingness to participate in the trial with their care recipient and rated the importance of nine considerations in hypothetical decisions to participate. Caregiver demographic characteristics were analyzed as predictors of trial participation in a base demographic model. In a second reasons model caregiver demographic characteristics and the rated importance of the nine considerations were separately analyzed as predictors; both models used survey-weighted logistic regression.

Result

The sample consisted of 610 dementia caregivers, including 156 non-Hispanic Black and 122 Hispanic caregiver participants. In the base demographic model, hypothetical trial participation was negatively associated with older caregiver age (OR (odds ratio) = 0.72, p = < 0.001). In the reasons model, the rated importance of a social responsibility to help others by participating in research was significantly associated with participation (OR = 1.56, p = 0.049), while the importance of the possibility of the care recipient experiencing serious side effects was negatively associated with participation (OR = 0.51, p = 0.003). In both models there was no significant difference in hypothetical participation between non-Hispanic Black and non-Hispanic White caregivers, or between Hispanic and non-Hispanic White caregivers.

Conclusion

Hispanic and non-Hispanic Black dementia caregivers were not less likely than non-Hispanic White dementia caregivers to participate in a hypothetical dementia clinical trial. Our study suggests that failures to recruit diverse populations in dementia clinical research are not attributable to less willingness among members of underrepresented groups but may instead reflect structural barriers and historic exclusion from trial participation.

Differentiating Prodromal Dementia with Lewy Bodies from Prodromal Alzheimer's Disease: A Pragmatic Review for Clinicians

This pragmatic review synthesises the current understanding of prodromal dementia with Lewy bodies (pDLB) and prodromal Alzheimer's disease (pAD), including clinical presentations, neuropsychological profiles, neuropsychiatric symptoms, biomarkers, and indications for disease management. The core clinical features of dementia with Lewy bodies (DLB)-parkinsonism, complex visual hallucinations, cognitive fluctuations, and REM sleep behaviour disorder are common prodromal symptoms. Supportive clinical features of pDLB include severe neuroleptic sensitivity, as well as autonomic and neuropsychiatric symptoms. The neuropsychological profile in mild cognitive impairment attributable to Lewy body pathology (MCI-LB) tends to include impairment in visuospatial skills and executive functioning, distinguishing it from MCI due to AD, which typically presents with impairment in memory. pDLB may present with cognitive impairment, psychiatric symptoms, and/or recurrent episodes of delirium, indicating that it is not necessarily synonymous with MCI-LB. Imaging, fluid and other biomarkers may play a crucial role in differentiating pDLB from pAD. The current MCI-LB criteria recognise low dopamine transporter uptake using positron emission tomography or single photon emission computed tomography (SPECT), loss of REM atonia on polysomnography, and sympathetic cardiac denervation using meta-iodobenzylguanidine SPECT as indicative biomarkers with slowing of dominant frequency on EEG among others as supportive biomarkers. This review also highlights the emergence of fluid and skin-based biomarkers. There is little research evidence for the treatment of pDLB, but pharmacological and non-pharmacological treatments for DLB may be discussed with patients. Non-pharmacological interventions such as diet, exercise, and cognitive stimulation may provide benefit, while evaluation and management of contributing factors like medications and sleep disturbances are vital. There is a need to expand research across diverse patient populations to address existing disparities in clinical trial participation. In conclusion, an early and accurate diagnosis of pDLB or pAD presents an opportunity for tailored interventions, improved healthcare outcomes, and enhanced quality of life for patients and care partners.

How Do Modifiable Risk Factors Affect Alzheimer's Disease Pathology or Mitigate Its Effect on Clinical Symptom Expression?

Epidemiological studies show that modifiable risk factors account for approximately 40% of the population variability in risk of developing dementia, including sporadic Alzheimer's disease (AD). Recent findings suggest that these factors may also modify disease trajectories of people with autosomal-dominant AD. With positron emission tomography imaging, it is now possible to study the disease many years before its clinical onset. Such studies can provide key knowledge regarding pathways for either the prevention of pathology or the postponement of its clinical expression. The former "resistance pathway" suggests that modifiable risk factors could affect amyloid and tau burden decades before the appearance of cognitive impairment. Alternatively, the resilience pathway suggests that modifiable risk factors may mitigate the symptomatic expression of AD pathology on cognition. These pathways are not mutually exclusive and may appear at different disease stages. Here, in a narrative review, we present neuroimaging evidence that supports both pathways in sporadic AD and autosomal-dominant AD. We then propose mechanisms for their protective effect. Among possible mechanisms, we examine neural and vascular mechanisms for the resistance pathway. We also describe brain maintenance and functional compensation as bases for the resilience pathway. Improved mechanistic understanding of both pathways may suggest new interventions.

Food resources and kitchen skills plus aerobic training (FoRKS+) for black adults with hypertension: A pilot trial protocol

BACKGROUND

Midlife hypertension is associated with cognitive decline and Alzheimer's disease and related dementia (ADRD), suggesting that blood pressure control may be a therapeutic target for dementia prevention. Given excess hypertension in non-Hispanic Black (NHB) adults, blood pressure control may also reduce ADRD disparities. We describe a pilot randomized controlled trial (RCT) to evaluate the feasibility and preliminary efficacy of a multicomponent lifestyle-based intervention versus enhanced usual care on cognition among middle-aged NHB adults.

METHODS AND STUDY DESIGN

The Food Resources and Kitchen Skills plus Aerobic Training (FoRKS+) study is a 2-arm, single-blinded trial that compares those receiving the FoRKS+ program (target N = 64) versus those receiving enhanced usual care (target N = 64) in local federally-qualified health centers. Key eligibility criteria include self-identified NHB adults between ages 35-75 with a mean systolic blood pressure ≥ 130 mm/Hg obtained from 24-h ambulatory blood pressure monitoring. The FoRKS+ program includes 5 weeks of hypertension self-management courses, 11 weeks of nutrition courses, and 12 weeks of aerobic training in dietitian and health coach-led virtual groups. We will collect data on primary cognitive outcomes, feasibility, hypothesized intervention mediators and moderators, and demographic and health covariates at baseline, near intervention weeks 16-, and 28 (primary outcome assessment), and week 52 follow-up. We will use mixed-effects modeling to examine intervention effects on cognition.

DISCUSSION

This pilot RCT will examine the feasibility and preliminary effects of a multicomponent lifestyle intervention on cognitive function in NHB adults, which may have implications for reducing health disparities in ADRD.

Normative data for the Digit Symbol Substitution for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA)

INTRODUCTION

Executive functioning and processing speed are crucial elements of neuropsychological assessment. To meet the needs of the Hispanic/Latino population, we aimed to provide normative data for the Digit Symbol Substitution (DSS) test.

METHODS

The target population for the Study of Latinos-Investigation of Neurocognitive Aging included six heritage backgrounds (n = 6177). Average age was 63.4 ± 8.3 years, 54.5% were female, and mean education was 11.0 ± 4.7 years. Participants were administered the DSS as part of a larger battery. Heritage-adjusted DSS scores, and percentile cut-points were created using survey-adjusted regression and quantile regression models.

RESULTS

Age, education, sex, heritage, and language preference were associated with DSS scores.

DISCUSSION

Significant correlates of DSS performance should be considered when evaluating cognitive performance. Representative DSS norms for Hispanics/Latinos will advance assessment and accuracy of neurocognitive disorder diagnosis in clinical practice. To facilitate interpretation, we provide norms to reduce test biases and developed an online dashboard.

Highlights

Normative data for the Digit Symbol Substitution (DSS) for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) This study is the first to develop norms for the DSS test across four regions of the United States.Factors such as age, education, sex, and Hispanic/Latino heritage and language preference are associated with differences in executive functioning and information processing speed.We created norms and an online dashboard (https://solincalab.shinyapps.io/dsst_shiny/) providing an easily accessible tool to evaluate processing speed and executive functioning in Hispanic/Latino adults.

Ethnoracial Identity and Cognitive Impairment: A Community Study

BACKGROUND

Identifying potentially modifiable risk factors associated with MCI in different ethnoracial groups could reduce MCI burden and health inequity in the population.

METHODS

Among 2845 adults aged 65+ years, we investigated potential risk exposures including education, physical and mental health, lifestyle, and sensory function, and their cross-sectional associations with MCI. We compared proportions of exposures between Black and White participants and explored relationships among race, MCI, and exposures. Logistic regression modeled MCI as a function of each exposure in the overall sample adjusting for age, sex, educational level, and race, and investigating race*exposure interactions.

RESULTS

Compared with White participants, Black participants had greater odds of MCI (OR 1.53; 95% CI, 1.13 to 2.06) and were more likely to report depressive symptoms, diabetes, and stroke, to have high blood pressure and BMI, and to be APOE - 4 carriers. Exposures associated with higher odds of MCI were diabetes, stroke, lifetime smoking, sleep disturbances, social isolation, loneliness, depression and anxiety symptoms, and vision and hearing loss. There were no significant interactions between race and any exposure.

CONCLUSIONS

Black participants had 53% higher odds of MCI adjusting for age, sex, and education. The same exposures were associated with MCI in Black and White participants.

Cognitive impairment and partnership status in the United States, 1998-2016, by sex, race/ethnicity, and education

Cognitively impaired adults without a partner are highly disadvantaged, as partners constitute an important source of caregiving and emotional support. With the application of innovative multistate models to the Health and Retirement Study, this paper is the first to estimate joint expectancies of cognitive and partnership status at age 50 by sex, race/ethnicity, and education in the United States. We find that women live a decade longer unpartnered than men. Women are also disadvantaged as they experience three more years as both cognitively impaired and unpartnered than men. Black women live over twice as long as cognitively impaired and unpartnered compared with White women. Lower-educated men and women live around three and five years longer, respectively, as cognitively impaired and unpartnered than more highly educated men and women. This study addresses a novel facet of partnership and cognitive status dynamics and examines their variations by key socio-demographic factors.

Cost of care for Alzheimer's disease and related dementias in the United States: 2016 to 2060

Medical and long-term care for Alzheimer's disease and related dementias (ADRDs) can impose a large economic burden on individuals and societies. We estimated the per capita cost of ADRDs care in the in the United States in 2016 and projected future aggregate care costs during 2020-2060. Based on a previously published methodology, we used U.S. Health and Retirement Survey (2010-2016) longitudinal data to estimate formal and informal care costs. In 2016, the estimated per patient cost of formal care was $28,078 (95% confidence interval [CI]: $25,893-$30,433), and informal care cost valued in terms of replacement cost and forgone wages was $36,667 ($34,025-$39,473) and $15,792 ($12,980-$18,713), respectively. Aggregate formal care cost and formal plus informal care cost using replacement cost and forgone wage methods were $196 billion (95% uncertainty range [UR]: $179-$213 billion), $450 billion ($424-$478 billion), and $305 billion ($278-$333 billion), respectively, in 2020. These were projected to increase to $1.4 trillion ($837 billion-$2.2 trillion), $3.3 trillion ($1.9-$5.1 trillion), and $2.2 trillion ($1.3-$3.5 trillion), respectively, in 2060.

Factors Associated With Psychological Wellbeing in Home Care Older Adults With Alzheimer's Disease: A Longitudinal Analysis

The long-term symptoms associated with Alzheimer's disease pose significant challenges to the psychological wellbeing of patients. This longitudinal study aims to analyze the effects of socioeconomic factors and physical health factors on the psychological wellbeing of older patients diagnosed with Alzheimer's disease (AD) receiving home care, as well as the moderating role of aging and care support in influencing their psychological wellbeing. Data from the Health and Retirement Study (N = 628 older Alzheimer's patients) were analyzed using pooled ordinary least squares fixed-effects models. Findings suggest that Alzheimer's patients' psychological wellbeing was significantly affected by factors including cohabitation, gender, assistance frequency, age, education, and daily activity challenges, with assistance and increasing age mitigating some daily difficulties. The findings underline the multifactorial nature of psychological wellbeing among older Alzheimer's patients in home care and the critical role of social and physical health determinants in shaping these outcomes.

Loss of Autonomy: Likely Dementia and Living Arrangement Transitions Among Mexicans and Mexican Americans

BACKGROUND AND OBJECTIVES

To examine the role of probable dementia on changes in living arrangements and mortality among very old Mexicans and Mexican Americans in 2 different nations.

RESEARCH DESIGN AND METHODS

We employ the Hispanic Established Population for the Epidemiologic Study of the Elderly and the Mexican Health and Aging Study, 2 comparable longitudinal data sets, to identify predictors of changes in living arrangements using multinomial logistic regression, controlling for cognitive status, demographic characteristics, and resources.

RESULTS

In Mexico, women with dementia who lived alone at baseline were more likely to become part of an extended family household than men with similar levels of cognitive impairment. A similar pattern emerges for the oldest Mexican-American women. Spousal loss increases the likelihood of living alone for women in the United States regardless of dementia. Although dementia elevates the risk of mortality for men living alone in the United States, in both countries, women in their 90s who lived alone with dementia had a lower risk of mortality relative to men.

DISCUSSION AND IMPLICATIONS

Longer life spans increase the risk of living alone with dementia in both countries, especially for women. Older individuals in both countries face financial hardships. Mexicans have limited formal options in dementia care. Mexican Americans with dementia continue to live alone despite low income although, unlike the Mexicans, they have access to Medicaid long-term care. For Mexico and the United States, the growing number of older individuals with dementia represents a growing public health concern.

Association Between Sleep Quantity and Quality in Early Adulthood With Cognitive Function in Midlife

BACKGROUND AND OBJECTIVE

Growing evidence supports an association between sleep quality and risk of dementia. However, little is known about whether objectively measured sleep duration and quality influence cognition in midlife, a period of importance for understanding the direction of the association between sleep and dementia. We examined the association between sleep duration and quality, measured when participants were in their mid-30s to late 40s, and midlife cognition assessed 11 years later among Black and White adults.

METHODS

As part of the Coronary Artery Risk Development in Young Adults cohort study, sleep duration and quality were assessed objectively using wrist actigraphy and subjectively by Pittsburgh Sleep Quality Index (PSQI) at 2003-2005. During 2015-2016, we evaluated midlife cognition using the Digit Symbol Substitution Test (DSST), Stroop test, Rey Auditory Verbal Learning Test, Montreal Cognitive Assessment (MoCA), and Letter Fluency and Category Fluency tests. We used multivariable logistic regression to examine the association between sleep parameters and poor cognitive performance, which was defined as a score that was >1 SD below the mean score.

RESULTS

The 526 participants (58% women and 44% Black) had a mean age of 40.1 ± 3.6 years at baseline, a mean sleep duration of 6.1 ± 1.1 hours, and mean sleep fragmentation index (calculated as the sum of the percentage of time spent moving and the percentage of immobile periods ≤1 minute) of 19.2 ± 8.1%, and 239 (45.6%) participants reported poor sleep as defined by a PSQI global score of >5. After adjustment for demographics, education, smoking, body mass index, depression, physical activity, hypertension, and diabetes, those in the highest vs lowest tertile of sleep fragmentation index had over twice the odds of having poor cognitive performance (>1 SD below the mean) on the DSST (odds ratio [OR] = 2.97; 95% CI 1.34-6.56), fluency (OR = 2.42; 95% CI 1.17-5.02), and MoCA test (OR = 2.29; 95% CI 1.06-4.94). The association between sleep fragmentation and cognitive performance did not differ by race or sex. Objective sleep duration or subjective sleep quality was not associated with cognition in midlife.

DISCUSSION

Actigraphy-measured high sleep fragmentation rather than sleep duration was associated with worse cognition among middle-aged Black and White men and women. Sleep quality is important for cognitive health even as early as midlife.

Forecasting the 20-Year Incidence of Dementia by Socioeconomic Status, Race/Ethnicity, and Region Based on Mid-Life Risk Factors in a U.S. Nationally Representative Sample

Background

Alzheimer's disease and related dementias (ADRD) incidence varies based on demographics, but mid-life risk factor contribution to this variability requires more research.

Objective

The purpose of this study is to forecast the 20-year incidence of dementia in the U.S. overall and stratified by race/ethnicity, socioeconomic status (SES), and U.S. geographic region given prior mid-life risk factor prevalence and to examine the extent to which risk factor differences 20 years ago may explain current SES, race/ethnicity, or regional disparities in dementia incidence.

Methods

We applied the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) prediction model to the 2006 wave of the Health and Retirement Study (HRS) in participants aged 45 to 64 to estimate the 20-year risk of incident ADRD.

Results

The 20-year risk of dementia among middle-aged Americans was 3.3% (95% CI: 3.2%, 3.4%). Dementia incidence was forecast to be 1.51 (95% CI: 1.32, 1.71) and 1.27 (95% CI: 1.14, 1.44) times that in Hispanic and Non-Hispanic Black individuals respectively compared statistically to Non-Hispanic White individuals given mid-life risk factors. There was a progressive increase in dementia risk from the lowest versus highest SES quintile. For geographic region, dementia incidence was forecast to be 1.17 (95% CI: 1.06, 1.30) and 1.27 (95% CI: 1.14, 1.43) times that in Midwestern and Southern individuals respectively compared statistically to Western individuals.

Conclusions

Some disparities in dementia incidence could be explained by differences in mid-life risk factors and may point toward policy interventions designed to lessen the ADRD disease burden through early prevention.

The importance of education for understanding variability of dementia onset in the United States

BACKGROUND

Greater levels of education are associated with lower risk of dementia, but less is known about how education is also associated with the compression of dementia incidence.

OBJECTIVE

We extend the literature on morbidity compression by evaluating whether increased levels of education are associated with greater dementia compression. We evaluate these patterns across race and gender groups.

METHODS

We use the Health and Retirement Study (2000-2016), a nationally representative longitudinal study of older adults in the United States. To evaluate the onset and compression of dementia across education groups, we examine the age-specific distribution of dementia events, identifying the modal age of onset and the standard deviation above the mode (a measure of compression).

RESULTS

While the modal age of onset is around 85 years among adults with a college degree, the modal age for adults with less than a high school education occurs before age 65 - at least a 20-year difference. The standard deviation of dementia onset is about three times greater for adults with less than a high school education compared to adults with a college degree. Patterns were consistent across race and gender groups.

CONCLUSION

This research highlights the variability of dementia experiences in the older population by documenting differences in longevity without dementia and compression of dementia onset among more educated adults and less educated adults.

CONTRIBUTION

We incorporate conceptual insights from the life span variability and compression literature to better understand education-dementia disparities in both the postponement and uncertainty of dementia onset in the US population.

State-level desegregation in the U.S. South and mid-life cognitive function among Black and White adults

RATIONALE

Black adults experience worse cognitive function than their White peers. Although educational attainment is an important predictor of cognitive function, other aspects of education, including school desegregation, may also shape this relationship. For Black adults who grew up in the U.S. South in the 1950s-1970s, exposure to school desegregation may have altered life course pathways critical for later cognitive function.

OBJECTIVE

We determined if state variation in exposure to school desegregation in the U.S. South was associated with cognitive function at mid-life, if the association varied by race, and if the association remained after adjustment for state-level education quality and respondents' educational attainment.

METHODS

We linked historical data on state-level school desegregation to the Health and Retirement Study, a nationally representative sample of U.S. adults aged 50 and older. We restricted our sample to Black (n = 1443) and White (n = 1507) adults born between 1948 and 1963 who resided in the U.S. South during primary school. We assessed three cognition outcomes: total cognitive function, episodic memory, and mental status. We estimated race-stratified linear regression models with cluster adjustment and a final model using state fixed effects.

RESULTS

Greater exposure to desegregated primary schooling was associated with higher cognitive function and episodic memory among Black but not White adults. Among Black adults, the association between school desegregation and cognitive function and episodic memory remained after adjustment for state-level education quality and educational attainment.

CONCLUSIONS

Our findings suggest that state-level school desegregation efforts played a consequential role in shaping the cognitive function of Black adults who grew up in the U.S. South.

Cost effectiveness of non-drug interventions that reduce nursing home admissions for people living with dementia

INTRODUCTION

Six million Americans live with Alzheimer's disease and Alzheimer's disease and related dementias (AD/ADRD), a major health-care cost driver. We evaluated the cost effectiveness of non-pharmacologic interventions that reduce nursing home admissions for people living with AD/ADRD.

METHODS

We used a person-level microsimulation to model the hazard ratios (HR) on nursing home admission for four evidence-based interventions compared to usual care: Maximizing Independence at Home (MIND), NYU Caregiver (NYU); Alzheimer's and Dementia Care (ADC); and Adult Day Service Plus (ADS Plus). We evaluated societal costs, quality-adjusted life years and incremental cost-effectiveness ratios.

RESULTS

All four interventions cost less and are more effective (i.e., cost savings) than usual care from a societal perspective. Results did not materially change in 1-way, 2-way, structural, and probabilistic sensitivity analyses.

CONCLUSION

Dementia-care interventions that reduce nursing home admissions save societal costs compared to usual care. Policies should incentivize providers and health systems to implement non-pharmacologic interventions.

Risk of neurodegenerative disease or dementia in adults with attention-deficit/hyperactivity disorder: a systematic review

Purpose of review

Several psychiatric disorders have been associated with an increased risk of developing a neurodegenerative disease and/or dementia. Attention-deficit/hyperactivity disorder (ADHD), a neurodevelopmental disorder, has been understudied in relation to dementia risk. We summarized existing literature investigating the risk of incident neurodegenerative disease or dementia associated with ADHD.

Recent findings

We searched five databases for cohort, case-control, and clinical trial studies investigating associations between ADHD and neurodegenerative diseases/dementia in May 2023. Study characteristics were extracted by two independent raters, and risk of bias was assessed using the Newcastle Ottawa Scale. Search terms yielded 2,137 articles, and seven studies (five cohort and two case-control studies) ultimately met inclusion criteria. Studies examined the following types of neurodegeneration: all-cause dementia, Alzheimer's disease, Parkinson's and Lewy body diseases, vascular dementia, and mild cognitive impairment. Heterogeneity in study methodology, particularly covariates used in analyses and types of ratios for risk reported, prevented a meta-analysis and data were therefore summarized as a narrative synthesis. The majority of studies (4/7) demonstrated an overall low risk of bias.

Summary

The current literature on risk of developing a neurodegenerative disease in ADHD is limited. Although the studies identified present evidence for a link between ADHD and subsequent development of dementia, the magnitude of the direct effect of ADHD on neurodegeneration is yet to be determined and better empirically designed studies are first needed. Furthermore, the mechanism of how or why ADHD is associated with an increased risk of developing a neurocognitive disorder is still unclear and should be explored in future studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022348976, the PROSPERO number is CRD42022348976.

The structural and social determinants of Alzheimer's disease related dementias

INTRODUCTION

The projected growth of Alzheimer's disease (AD) and AD-related dementia (ADRD) cases by midcentury has expanded the research field and impelled new lines of inquiry into structural and social determinants of health (S/SDOH) as fundamental drivers of disparities in AD/ADRD.

METHODS

In this review, we employ Bronfenbrenner's ecological systems theory as a framework to posit how S/SDOH impact AD/ADRD risk and outcomes.

RESULTS

Bronfenbrenner defined the "macrosystem" as the realm of power (structural) systems that drive S/SDOH and that are the root cause of health disparities. These root causes have been discussed little to date in relation to AD/ADRD, and thus, macrosystem influences, such as racism, classism, sexism, and homophobia, are the emphasis in this paper.

DISCUSSION

Under Bronfenbrenner's macrosystem framework, we highlight key quantitative and qualitative studies linking S/SDOH with AD/ADRD, identify scientific gaps in the literature, and propose guidance for future research.

HIGHLIGHTS

Ecological systems theory links structural/social determinants to AD/ADRD. Structural/social determinants accrue and interact over the life course to impact AD/ADRD. Macrosystem is made up of societal norms, beliefs, values, and practices (e.g., laws). Most macro-level determinants have been understudied in the AD/ADRD literature.

Dementia literacy of racially minoritized people in a Chinese society: a qualitative study among South Asian migrants in Hong Kong

OBJECTIVES

Research on dementia literacy in Chinese societies is still emerging, and this is especially the case among racially minoritized groups. The present study explored the knowledge, causal beliefs, and help-seeking behaviors of South Asian migrants in Hong Kong about dementia. It also investigated existing community barriers related to dementia knowledge and help-seeking.

DESIGN

We conducted a qualitative study from a purposive sample of 38 older people and family caregivers from India, Pakistan, and Nepal who lived in Hong Kong. Focus groups and individual in-depth interviews were used to gather information, while thematic analysis was employed to analyze the data.

RESULTS

Five main themes were identified: normalization with stigmatization of dementia; spiritual and psychosocial attributions of dementia; familial responsibility despite potential caregiving burden; uncertainties versus openness to professional care; and barriers and opportunities in dementia literacy. Ethnic minorities recognized dementia as a disease of normal aging or a mental disorder. They also perceived spiritual and psychosocial factors as their main causes. While participants recognized the potential burden of dementia caregiving, families were their first point of help-seeking, as many of them expressed contrasting feelings of confidence or doubt toward professional services. Utilization of health education strategies, together with collaboration with community leaders, could address the barriers to dementia literacy.

CONCLUSIONS

This is the first study to explore how ethnic minorities in Asia perceive dementia and its related help-seeking behaviors in their communities. South Asian migrants in Hong Kong have a limited understanding of dementia and may experience delays in obtaining relevant community services. While culture influenced their knowledge, health education may address their misperceptions and help-seeking behaviors toward dementia. Culture- and language-specific programs could also improve dementia knowledge and health service access.

Barriers and solutions to Alzheimer's disease clinical trial participation for Black Americans

Introduction

Black Americans are disproportionately burdened by Alzheimer's disease (AD) relative to other racial groups in the United States and continue to be underrepresented in AD clinical trials. This review explores the primary barriers for participation in clinical trials among Black Americans and provides literature-based recommendations to improve the inclusion of Black Americans in AD clinical trials.

Methods

We searched electronic databases and gray literature for articles published in the United States through January 1, 2023, ultimately identifying 26 key articles for inclusion.

Results

Barriers to participation in clinical trials for Black Americans are rooted in social determinants of health, including access to quality education and information, access to health care, economic stability, built environment, and community context. Best practices to improve the inclusion of Black Americans in clinical trials require pharmaceutical companies to adopt a multifaceted approach, investing in innovative strategies for site selection, development of local partnerships, outreach, and education.

Discussion

While multisectoral action must occur to effectively address the disproportionate burden of AD on Black Americans, the pharmaceutical industry has an important part to play in this space due to their central role in product development and clinical trials.

Decomposing interaction and mediating effects of race/ethnicity and circulating blood levels of cystatin C on cognitive status in the United States health and retirement study

Background and objectives

Elevated circulating cystatin C is associated with cognitive impairment in non-Hispanic Whites, but its role in racial disparities in dementia is understudied. In a nationally representative sample of older non-Hispanic White, non-Hispanic Black, and Hispanic adults in the United States, we use mediation-interaction analysis to understand how racial disparities in the cystatin C physiological pathway may contribute to racial disparities in prevalent dementia.

Methods

In a pooled cross-sectional sample of the Health and Retirement Study (n = 9,923), we employed Poisson regression to estimate prevalence ratios and to test the relationship between elevated cystatin C (>1.24 vs. ≤1.24 mg/L) and impaired cognition, adjusted for demographics, behavioral risk factors, other biomarkers, and chronic conditions. Self-reported racialized social categories were a proxy measure for exposure to racism. We calculated additive interaction measures and conducted four-way mediation-interaction decomposition analysis to test the moderating effect of race/ethnicity and mediating effect of cystatin C on the racial disparity.

Results

Overall, elevated cystatin C was associated with dementia (prevalence ratio [PR] = 1.2; 95% CI: 1.0, 1.5). Among non-Hispanic Black relative to non-Hispanic White participants, the relative excess risk due to interaction was 0.7 (95% CI: -0.1, 2.4), the attributable proportion was 0.1 (95% CI: -0.2, 0.4), and the synergy index was 1.1 (95% CI: 0.8, 1.8) in a fully adjusted model. Elevated cystatin C was estimated to account for 2% (95% CI: -0, 4%) for the racial disparity in prevalent dementia, and the interaction accounted for 8% (95% CI: -5, 22%). Analyses for Hispanic relative to non-white participants suggested moderation by race/ethnicity, but not mediation.

Discussion

Elevated cystatin C was associated with dementia prevalence. Our mediation-interaction decomposition analysis suggested that the effect of elevated cystatin C on the racial disparity might be moderated by race/ethnicity, which indicates that the racialization process affects not only the distribution of circulating cystatin C across minoritized racial groups, but also the strength of association between the biomarker and dementia prevalence. These results provide evidence that cystatin C is associated with adverse brain health and this effect is larger than expected for individuals racialized as minorities had they been racialized and treated as non-Hispanic White.

Improving Adherence to a Mediterranean Ketogenic Nutrition Program for High-Risk Older Adults: A Pilot Randomized Trial

(1) Background: Mediterranean ketogenic nutrition (MKN) may directly target multiple neurobiological mechanisms associated with dementia risk in older adults. Despite its promise, this type of nutrition can be challenging to learn and adhere to in a healthy manner. Our team used the National Institutes of Health Obesity Related Behavioral Intervention Trials (NIH ORBIT) model to develop and pilot a program to help older adults with memory concerns use MKN. (2) Methods: Using a two-arm, randomized design, we evaluated an MKN Adherence (MKNA) program compared to an MKN education (MKNE) program (N = 58). The primary difference between study arms involved the use of motivational interviewing (MI) strategies and behavior change techniques (BCT) only in the MKNA arm. Participants were included if they evidenced subjective memory concerns or objective memory impairment on the Montreal Cognitive Assessment (Score 19 ≤ 26). Primary outcomes examined included feasibility, acceptability, adherence, and clinical outcomes associated with the program. (3) Results: Overall, there was relatively high program completion in both groups, with 79% of participants completing the 6-week program. The recruitment protocol required adjustment but was successful in reaching the target sample size. Retention (82%) and session attendance (91%) were higher in the MKNA arm compared to the MKNE (retention = 72%; attendance = 77%). Overall, most participants in both groups rated the program as "excellent" using the client satisfaction questionnaire. Participants in the MKNA arm evidenced higher objective and self-reported adherence to MKN during the 6-week program. Further, there was some evidence of clinical benefits of the program, although these effects diminished as adherence decreased in the 3 months follow-up. (4) Discussion: This pilot trial demonstrated that the MKN program incorporating MI and BCT strategies may better engage and retain participants than a nutrition education program alone, although participants in both groups reported high satisfaction.

Focusing Our Attention on Socially Responsive Professional Education to Serve Ethnogeriatric Populations With Neurogenic Communication Disorders in the United States

PURPOSE

This viewpoint discusses a plausible framework to educate future speech-language pathologists (SLPs) as socially responsive practitioners who serve and advocate for the burgeoning vulnerable ethnogeriatric populations with neurogenic communication disorders.

METHOD

We provide an overview of the demographic, epidemiological, and biopsychosocial context that supports the implementation of equity-based, population-grounded educational approaches for speech-language pathology services in ethnogeriatric neurorehabilitation caseloads and discuss a plausible perspective based on the educational social determinants of health (SDOH) framework by the National Academies of Sciences, Engineering, and Medicine.

RESULTS

The NASEM's three-domain SDOH educational perspective integrates education, community, and organization to create a self-reinforcing pedagogical coproduction that, grounded in the synergized partnerships of educational institutions, engaged communities, and organizational leadership, aims to address systemic drivers of health perpetuating ethnoracial disparities in health, care, and outcomes.

CONCLUSION

Exponentially growing vulnerable ethnogeriatric populations with age-related neurogenic communication disorders warrant the implementation of health equity education strategies to train technically prepared, socially conscious SLPs as service providers and advocates.

The relationship of history of psychiatric and substance use disorders on risk of dementia among racial and ethnic groups in the United States

Introduction

Dementia is characterized by significant declines in cognitive, physical, social, and behavioral functioning, and includes multiple subtypes that differ in etiology. There is limited evidence of the influence of psychiatric and substance use history on the risk of dementia subtypes among older underrepresented racial/ethnic minorities in the United States. Our study explored the role of psychiatric and substance use history on the risk of etiology-specific dementias: Alzheimer's disease (AD) and vascular dementia (VaD), in the context of a racially and ethnically diverse sample based on national data.

Methods

We conducted secondary data analyses based on the National Alzheimer's Coordinating Center Uniform Data Set (N = 17,592) which is comprised a large, racially, and ethnically diverse cohort of adult research participants in the network of US Alzheimer Disease Research Centers (ADRCs). From 2005 to 2019, participants were assessed for history of five psychiatric and substance use disorders (depression, traumatic brain injury, other psychiatric disorders, alcohol use, and other substance use). Cox proportional hazard models were used to examine the influence of psychiatric and substance use history on the risk of AD and VaD subtypes, and the interactions between psychiatric and substance use history and race/ethnicity with adjustment for demographic and health-related factors.

Results

In addition to other substance use, having any one type of psychiatric and substance use history increased the risk of developing AD by 22-51% and VaD by 22-53%. The risk of other psychiatric disorders on AD and VaD risk varied by race/ethnicity. For non-Hispanic White people, history of other psychiatric disorders increased AD risk by 27%, and VaD risk by 116%. For African Americans, AD risk increased by 28% and VaD risk increased by 108% when other psychiatric disorder history was present.

Conclusion

The findings indicate that having psychiatric and substance use history increases the risk of developing AD and VaD in later life. Preventing the onset and recurrence of such disorders may prevent or delay the onset of AD and VaD dementia subtypes. Prevention efforts should pay particular attention to non-Hispanic White and African American older adults who have history of other psychiatric disorders.Future research should address diagnostic shortcomings in the measurement of such disorders in ADRCs, especially with regard to diverse racial and ethnic groups.

The Mediating Role of Systemic Inflammation and Moderating Role of Race/Ethnicity in Racialized Disparities in Incident Dementia: A Decomposition Analysis

Background

Exposure to systemic racism is linked to increased dementia burden. To assess systemic inflammation as a potential pathway linking exposure to racism and dementia disparities, we investigated the mediating role of C-reactive protein (CRP), a systemic inflammation marker, and the moderating role of race/ethnicity on racialized disparities in incident dementia.

Methods

In the US Health and Retirement Study (n=5,143), serum CRP was measured at baseline (2006, 2008 waves). Incident dementia was classified by cognitive tests over a six-year follow-up. Self-reported racialized categories were a proxy for exposure to the racialization process. We decomposed racialized disparities in dementia incidence (non-Hispanic Black and/or Hispanic vs. non-Hispanic White) into 1) the mediated effect of CRP, 2) the moderated portion attributable to the interaction between racialized group membership and CRP, and 3) the controlled direct effect (other pathways through which racism operates).

Results

The 6-year cumulative incidence of dementia was 15.5%. Among minoritized participants (i.e., non-Hispanic Black and/or Hispanic), high CRP levels (> 75th percentile or 4.57μg/mL) was associated with 1.27 (95%CI: 1.01,1.59) times greater risk of incident dementia than low CRP (≤4.57μg/mL). Decomposition analysis comparing minoritized versus non-Hispanic White participants showed that the mediating effect of CRP accounted for 2% (95% CI: 0%, 6%) of the racial disparity, while the interaction effect between minoritized group status and high CRP accounted for 12% (95% CI: 2%, 22%) of the disparity. Findings were robust to potential violations of causal mediation assumptions.

Conclusions

Systemic inflammation mediates racialized disparities in incident dementia.

Trends in Gender and Racial/Ethnic Disparities in Physical Disability and Social Support Among U.S. Older Adults With Cognitive Impairment Living Alone, 2000-2018

Background and Objectives

Informal care is the primary source of support for older adults with cognitive impairment, yet is less available to those who live alone. We examined trends in the prevalence of physical disability and social support among older adults with cognitive impairment living alone in the United States.

Research Design and Methods

We analyzed 10 waves of data from the U.S. Health and Retirement Survey spanning 2000-2018. Eligible people were those aged ≥65, having cognitive impairment, and living alone. Physical disability and social support were measured via basic and instrumental activities of daily living (BADLs, IADLs). We estimated linear temporal trends for binary/integer outcomes via logistic/Poisson regression, respectively.

Results

A total of 20 070 participants were included. Among those reporting BADL/IADL disability, the proportion unsupported for BADLs decreased significantly over time (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.97-0.99), and the proportion unsupported for IADLs increased (OR = 1.02, CI 1.01-1.04). Among those receiving IADL support, the number of unmet IADL support needs increased significantly over time (relative risk [RR] 1.04, CI 1.03-1.05). No gender disparities were found for these trends. Over time, Black respondents had a relatively increasing trend of being BADL-unsupported (OR = 1.03, CI 1.0-1.05) and Hispanic and Black respondents had a relatively increasing trend in the number of unmet BADL needs (RR = 1.02, CI 1.00-1.03; RR = 1.01, CI 1.00-1.02, respectively), compared to the corresponding trends in White respondents.

Discussion and Implications

Among lone-dwelling U.S. older adults with cognitive impairment, fewer people received IADL support over time, and the extent of unmet IADL support needs increased. Racial/ethnic disparities were seen both in the prevalence of reported BADL/IADL disability and unmet BADL/IADL support needs; some but not all were compatible with a reduction in disparity over time. This evidence could prompt interventions to reduce disparities and unmet support needs.

Population-Based Mini-Mental State Examination Norms in Adults of Mexican Heritage in the Cameron County Hispanic Cohort

BACKGROUND

Accurately identifying cognitive changes in Mexican American (MA) adults using the Mini-Mental State Examination (MMSE) requires knowledge of population-based norms for the MMSE, a scale which has widespread use in research settings.

OBJECTIVE

To describe the distribution of MMSE scores in a large cohort of MA adults, assess the impact of MMSE requirements on their clinical trial eligibility, and explore which factors are most strongly associated with their MMSE scores.

METHODS

Visits between 2004-2021 in the Cameron County Hispanic Cohort were analyzed. Eligible participants were ≥18 years old and of Mexican descent. MMSE distributions before and after stratification by age and years of education (YOE) were assessed, as was the proportion of trial-aged (50-85- year-old) participants with MMSE <24, a minimum MMSE cutoff most frequently used in Alzheimer's disease (AD) clinical trials. As a secondary analysis, random forest models were constructed to estimate the relative association of the MMSE with potentially relevant variables.

RESULTS

The mean age of the sample set (n = 3,404) was 44.4 (SD, 16.0) years old and 64.5% female. Median MMSE was 28 (IQR, 28-29). The percentage of trial-aged participants (n = 1,267) with MMSE <24 was 18.6%; 54.3% among the subset with 0-4 YOE (n = 230). The five variables most associated with the MMSE in the study sample were education, age, exercise, C-reactive protein, and anxiety.

CONCLUSION

The minimum MMSE cutoffs in most phase III prodromal-to-mild AD trials would exclude a significant proportion of trial-aged participants in this MA cohort, including over half of those with 0-4 YOE.

Health concerns and attitudes towards research participation in a community of rural Black Americans

OBJECTIVES

Describe health concerns of Black Americans as they age and what influences their participation in aging and clinical research.

METHODS

Fifty participants attended focus groups and completed questionnaires to identify barriers to research participation and attitudes toward dementia screening. Bivariate correlations explored associations between barriers to research participation and attitudes toward dementia screening.

RESULTS

Cancer, hereditary conditions, vascular conditions, memory disorders, and psychological disorders were the greatest health concerns. Time demands, mistrust, lack of knowledge about potential research, and stigma were identified as barriers for research participation. Incentives, better understanding of how proposed research will benefit the community, lifestyle modification studies, active presence of principal researchers/clinicians, and community investment were identified as factors to improve participation. Questionnaires revealed mistrust and religious beliefs to be among the primary barriers. Attitudes toward dementia screening reflected perceived stigma, suffering, and subsequent loss of independence. Higher barriers to participation were associated with perceived stigma and loss of independence related to dementia screening.

CONCLUSIONS

Successfully recruiting Black Americans for aging and clinical research remains a challenge. This study identifies barriers to participation and offers suggestions for planning and recruitment.

Clinical Trial Site Perspectives and Practices on Study Participant Diversity and Inclusion

Clinical trial participant populations fail to adequately represent target populations that drugs are intended to serve. Improving racial and ethnic diversity of clinical trial participants is essential for generalizable, quality clinical research results and ensuring social and medical equity. Site-level clinical research professionals (CRPs) have unique insights on diversity improvement strategies for clinical trial enrollment. A survey was distributed to current CRPs working at clinical research sites in the United States to describe current practices and perceptions of the impact these practices have on participant diversity. Subsequently, descriptive quantitative analysis and inductive content analysis were performed. For the practices surveyed, there are discrepancies between frequency of use and perceived impact on diversity enrollment. Common current practices include phone-based or telemedicine study visits, electronic/digital data collection, and participant compensation. However, we report travel reimbursement and services, translated documents and translator services, and adequate participant compensation as most impactful on diverse enrollment. A multistakeholder approach is necessary to enhance diversity and inclusion (D&I) of study participants. Besides large-scale solutions such as countering community distrust, actionable steps are needed by sponsors and study sites to improve D&I of trial participants. Study leadership at the sponsor, contract research organization (CRO), and site-level should create diversity plans prior to study start, and CRO and sponsor budgets should consider D&I strategies during study planning. Planning should incorporate strategies to improve D&I including adequate participant compensation, translated documents and translator services, and travel reimbursements.

The identification of clusters of risk factors and their association with hospitalizations or emergency department visits in home health care

AIMS

To identify clusters of risk factors in home health care and determine if the clusters are associated with hospitalizations or emergency department visits.

DESIGN

A retrospective cohort study.

METHODS

This study included 61,454 patients pertaining to 79,079 episodes receiving home health care between 2015 and 2017 from one of the largest home health care organizations in the United States. Potential risk factors were extracted from structured data and unstructured clinical notes analysed by natural language processing. A K-means cluster analysis was conducted. Kaplan-Meier analysis was conducted to identify the association between clusters and hospitalizations or emergency department visits during home health care.

RESULTS

A total of 11.6% of home health episodes resulted in hospitalizations or emergency department visits. Risk factors formed three clusters. Cluster 1 is characterized by a combination of risk factors related to "impaired physical comfort with pain," defined as situations where patients may experience increased pain. Cluster 2 is characterized by "high comorbidity burden" defined as multiple comorbidities or other risks for hospitalization (e.g., prior falls). Cluster 3 is characterized by "impaired cognitive/psychological and skin integrity" including dementia or skin ulcer. Compared to Cluster 1, the risk of hospitalizations or emergency department visits increased by 1.95 times for Cluster 2 and by 2.12 times for Cluster 3 (all p < .001).

CONCLUSION

Risk factors were clustered into three types describing distinct characteristics for hospitalizations or emergency department visits. Different combinations of risk factors affected the likelihood of these negative outcomes.

IMPACT

Cluster-based risk prediction models could be integrated into early warning systems to identify patients at risk for hospitalizations or emergency department visits leading to more timely, patient-centred care, ultimately preventing these events.

PATIENT OR PUBLIC CONTRIBUTION

There was no involvement of patients in developing the research question, determining the outcome measures, or implementing the study.

The Burden of Dementia Spectrum Disorders and Associated Comorbid and Demographic Features

Dementia spectrum disorders (DSDs) are a major cause of mortality and disability worldwide. DSDs encompass a large group of medical conditions that all ultimately lead to major functional and cognitive decline and disability. Demographic and comorbid conditions that are associated with DSDs have significant prognostic and preventive implications. In this article, we will discuss the global and regional burden of DSDs and cover key demographic and clinical conditions linked with DSDs. In the absence of disease-modifying treatments, the role of primary prevention has become more prominent. Implementation of preventive measures requires an understanding of predisposing and exacerbating factors.

Global estimates on the number of persons across the Alzheimer's disease continuum

INTRODUCTION

Global estimates on numbers of persons in early stages of Alzheimer's disease (AD), including prodromal and preclinical, are lacking, yet are needed to inform policy decisions on preventive measures and planning for future therapies targeting AD pathology.

METHODS

We synthesized the literature on prevalence across the AD continuum and derived a model estimating the number of persons, stratified by 5-year age groups, sex, and disease stage (AD dementia, prodromal AD, and preclinical AD).

RESULTS

The global number of persons with AD dementia, prodromal AD, and preclinical AD were estimated at 32, 69, and 315 million, respectively. Together they constituted 416 million across the AD continuum, or 22% of all persons aged 50 and above.

DISCUSSION

Considering predementia stages, the number of persons with AD is much larger than conveyed in available literature. Our estimates are uncertain, especially for predementia stages in low- and middle-income regions where biomarker studies are missing.

A Web-Based Decision Aid for Caregivers of Persons With Dementia With Firearm Access (Safe at Home Study): Protocol for a Randomized Controlled Trial

BACKGROUND

Firearm safety among individuals with Alzheimer disease and related dementias (ADRD) is an underdiscussed and underresearched concern in the United States, especially given the growing population of community-dwelling adults with ADRD. The "Safety in Dementia" (SiD) web-based decision aid was developed to support caregivers in addressing firearm access; the efficacy of SiD is unknown.

OBJECTIVE

Through the SiD decision aid, the Safe at Home (S@H) study aims to support caregivers in making decisions about home safety that align with their goals and values, and behaviors regarding firearm access for persons with ADRD and firearm access.

METHODS

The S@H study is a 2-armed randomized controlled trial to test the effect of the SiD decision aid on caregivers of community-dwelling adults with ADRD who have firearm access. S@H aims to recruit 500 ADRD caregivers (age ≥18 years, fluent in English or Spanish, and in the United States) through online or social media advertisements and through relevant organizations. Participants are randomized to view SiD or a control website at their own pace; all participants complete web-based questionnaires at baseline, 2 weeks, 2 months, and 6 months. The primary outcome is immediate preparation for decision-making; secondary outcomes include longitudinal decision outcomes and self-reported modifications to firearm access. The relative reach and effectiveness of each recruitment method (online/social media and through relevant organizations) will be assessed by examining differences in caregiver participation, retention rates, and relative cost.

RESULTS

The study enrollment began in May 2022. As of December 2022, a total of 117 participants had enrolled.

CONCLUSIONS

The S@H study is the first randomized trial of a firearm safety decision aid for ADRD caregivers. The results from this study will inform how best to support caregivers in decision-making regarding firearm safety. Further, results may guide approaches for recruiting caregivers and for dissemination of resources.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05173922; https://clinicaltrials.gov/ct2/show/NCT05173922.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43702.

Enhancing Clinical Data Analysis by Explaining Interaction Effects between Covariates in Deep Neural Network Models

Deep neural network (DNN) is a powerful technology that is being utilized by a growing number and range of research projects, including disease risk prediction models. One of the key strengths of DNN is its ability to model non-linear relationships, which include covariate interactions. We developed a novel method called interaction scores for measuring the covariate interactions captured by DNN models. As the method is model-agnostic, it can also be applied to other types of machine learning models. It is designed to be a generalization of the coefficient of the interaction term in a logistic regression; hence, its values are easily interpretable. The interaction score can be calculated at both an individual level and population level. The individual-level score provides an individualized explanation for covariate interactions. We applied this method to two simulated datasets and a real-world clinical dataset on Alzheimer's disease and related dementia (ADRD). We also applied two existing interaction measurement methods to those datasets for comparison. The results on the simulated datasets showed that the interaction score method can explain the underlying interaction effects, there are strong correlations between the population-level interaction scores and the ground truth values, and the individual-level interaction scores vary when the interaction was designed to be non-uniform. Another validation of our new method is that the interactions discovered from the ADRD data included both known and novel relationships.

Neuropsychiatric Symptoms and Trajectories of Dependence and Cognition in a Sample of Community-dwelling Older Adults with Dementia

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS), including psychotic symptoms (hallucinations, illusions, delusions), agitation/aggression, and depressed mood, are common in individuals with Alzheimer's disease (AD) and predict poorer outcomes, including faster disease progression. We aimed to evaluate associations between NPS and cognition and dependence in a multi-ethnic sample of community-dwelling older adults with AD.

METHODS

Predictors 3 (P3) is a cohort study of AD disease courses recruiting older adults aged 65 and above residing in upper Manhattan. A total of 138 of 293 participants had probable AD at the study baseline. We fit linear mixed models to examine longitudinal associations of time-varying NPS (psychotic symptoms, agitation/aggression, and depressed mood) with dependence and cognition, adjusted for race-ethnicity, sex, education, age, clinical dementia rating score, APOE-ε4, and comorbidity burden; separate interaction models were fit for age, Hispanic ethnicity, and sex.

RESULTS

Psychotic symptoms were associated with faster rates of increasing dependence and declining cognition over time, agitation/aggression with faster rates of declining cognition, and depressed mood with faster rates of increasing dependence. Among psychotic symptoms, delusions, but not hallucinations or illusions, were associated with worse outcome trajectories. Depressed mood predicted an accelerated increase in dependence in males but not females.

CONCLUSION

Our results confirm and extend prior results in clinic-based samples. The presence of NPS was associated with worse trajectories of dependence and cognition in this muti-ethnic sample of older adults with AD. Importantly, sex modified the association between depressed mood and dependence. Our results on NPS as predictors of differential AD progression in a community-dwelling, ethnically diverse sample serve to better inform the clinical care of patients and the future development of AD therapies.

Health equity considerations in pragmatic trials in Alzheimer's and dementia disease: Results from a methodological review

Introduction

To improve dementia care delivery for persons across all backgrounds, it is imperative that health equity is integrated into pragmatic trials.

Methods

We reviewed 62 pragmatic trials of people with dementia published 2014 to 2019. We assessed health equity in the objectives; design, conduct, analysis; and reporting using PROGRESS-Plus which stands for Place of residence, Race/ethnicity, Occupation, Gender/sex, Religion, Education, Socioeconomic status, Social capital, and other factors such as age and disability.

Results

Two (3.2%) trials incorporated equity considerations into their objectives; nine (14.5%) engaged with communities; 4 (6.5%) described steps to increase enrollment from equity-relevant groups. Almost all trials (59, 95.2%) assessed baseline balance for at least one PROGRESS-Plus characteristic, but only 10 (16.1%) presented subgroup analyses across such characteristics. Differential recruitment, attrition, implementation, adherence, and applicability across PROGRESS-Plus were seldom discussed.

Discussion

Ongoing and future pragmatic trials should more rigorously integrate equity considerations in their design, conduct, and reporting.

Highlights

Few pragmatic trials are explicitly designed to inform equity-relevant objectives.Few pragmatic trials take steps to increase enrollment from equity-relevant groups.Disaggregated results across equity-relevant groups are seldom reported.Adherence to existing tools (e.g., IMPACT Best Practices, CONSORT-Equity) is key.

Racial/Ethnic Disparities in Misidentification of Dementia in Medicare Claims: Results from the Washington Heights-Inwood Columbia Aging Project

BACKGROUND

Misidentification of dementia in Medicare claims is quite common.

OBJECTIVE

We examined potential race/ethnic disparities in misidentification of dementia in Medicare claims in a diverse cohort of older adults who underwent careful clinical assessment.

METHODS

Participants were enrolled in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a multiethnic, population-based, prospective study of cognitive aging in which dementia status was assessed using a rigorous clinical protocol. ICD-9-CM and ICD-10-CM diagnosis codes in all available Medicare claims (1999-2019) were compared to clinical dementia diagnosis and categorized into three mutually exclusive groups: 1) congruent-, 2) over-, and 3) under- identification during the study period. Multinomial logistic regression model was used to examine the relationship between race (White, African American/Black, other) and ethnicity (Hispanic/Latinx, non-Hispanic/Latinx) and congruency of dementia identification after controlling for clinical (cognition, function, comorbidities) and demographic characteristics (age, sex, education), and inpatient and outpatient utilization.

RESULTS

Across all person-years, 88.4% had congruent identification of dementia compared to clinical diagnosis, in 4.1% of the times participants were over-identified with dementia, and 7.5% of the times the participants were under-identified. Rates of misidentification was higher in minority participants than in White, non-Hispanic participants. Multivariable estimation results showed that the probability of over-identification with dementia was 2.2% higher for African American/Black than White (p = 0.05) and 2.7% higher for Hispanic participants than non-Hispanics (p = 0.03) participants. Differences in under-identification by race/ethnicity were not statistically significant.

CONCLUSIONS

African American/Black and Hispanic participants were more likely over-identified with dementia in Medicare claims.

Increasing participant diversity in AD research: Plans for digital screening, blood testing, and a community-engaged approach in the Alzheimer's Disease Neuroimaging Initiative 4

INTRODUCTION

The Alzheimer's Disease Neuroimaging Initiative (ADNI) aims to validate biomarkers for Alzheimer's disease (AD) clinical trials. To improve generalizability, ADNI4 aims to enroll 50-60% of its new participants from underrepresented populations (URPs) using new biofluid and digital technologies. ADNI4 has received funding from the National Institute on Aging beginning September 2022.

METHODS

ADNI4 will recruit URPs using community-engaged approaches. An online portal will screen 20,000 participants, 4000 of whom (50-60% URPs) will be tested for plasma biomarkers and APOE. From this, 500 new participants will undergo in-clinic assessment joining 500 ADNI3 rollover participants. Remaining participants (∼3500) will undergo longitudinal plasma and digital cognitive testing. ADNI4 will add MRI sequences and new PET tracers. Project 1 will optimize biomarkers in AD clinical trials.

RESULTS AND DISCUSSION

ADNI4 will improve generalizability of results, use remote digital and blood screening, and continue providing longitudinal clinical, biomarker, and autopsy data to investigators.

Patterns of sleep disturbances across stages of cognitive decline

OBJECTIVES

The purpose of this study was to investigate insomnia symptoms and excessive sleep/sluggishness across stages of cognitive decline (cognitively normal [CN], Cognitively Impairment, Not Demented [CIND], dementia) in a large, racially/ethnically diverse sample of older adults (70+) in the US. We also examined whether sleep disturbances at baseline predicted conversion to CIND or dementia at follow-up.

METHODS

In this secondary analysis of the Aging, Demographics, and Memory Study (ADAMS) supplement of the Health Retirement Study, we analyzed patterns of informant-reported insomnia and excessive sleep symptoms among three groups of older adults (n = 846): CN, CIND, and dementia.

RESULTS

CIND adults were significantly more likely to have informant-reported insomnia symptoms than those in the CN group (p = 0.013). This was driven by a significant race/ethnicity-by-insomnia interaction with diagnostic status (p = 0.029), such that CIND Black and Hispanic older adults had increased insomnia symptom rates compared to CN, whereas White adults had similar insomnia symptoms across diagnostic status. Across all racial/ethnic groups, the prevalence of excessive sleep symptoms increased stepwise from CN to CIND to dementia (p < 0.001). Overall, insomnia symptoms at baseline predicted conversion from CN to CIND (p < 0.001, OR = 0.288; 95% CI: 0.143-0.580) at 4-year (approximate) follow-up; there was no relationship between baseline insomnia or excessive sleep/sluggishness symptoms and conversion from CIND to dementia.

DISCUSSION/CONCLUSION

This study provides evidence for the increased risk of insomnia symptoms among Hispanic and Black older adults with CIND, and indicates that insomnia symptoms may be associated with increased risk for development of cognitive impairment.

Sex Differences in the Associations of Obesity with Tau, Amyloid PET, and Cognitive Outcomes in Preclinical Alzheimer's Disease: Cross-Sectional A4 Study

BACKGROUND

The association between obesity and Alzheimer's disease (AD) is complex. Recent studies indicated the relationships between obesity and AD may differ by sex, and women may benefit from being overweight in terms of AD risk.

OBJECTIVE

We investigated whether sex modifies the associations of obesity with tau positron emission tomography (PET), amyloid PET, and cognition in preclinical AD.

METHODS

We included 387 cognitively-unimpaired amyloid-positive participants (221 women, 166 men, 87.6% non-Hispanic White) with available 18F-flortaucipir PET, 18F-florbetapir PET, and completed the Preclinical Alzheimer Cognitive Composite (PACC) tests from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study. Participants were categorized based on body mass index (BMI: kg/m2): normal-weight (BMI: 18.5-25), overweight (BMI: 25-30), and obese (BMI≥30).

RESULTS

Significant sex by BMI category interactions on PACC and its components: Mini-Mental State Examination (MMSE) and Reminding Test-Free+Total Recall (FCSRT96) revealed that overweight and obese women outperformed normal-weight women on FCSRT96, while obese men showed poorer MMSE performance than normal-weight men. These interactions were independent of APOE4. There were no significant interactions of sex by BMI category on tau and amyloid PET. However, sex-stratified analyses observed obesity was associated with less regional tau and mean cortical amyloid in women, not in men.

CONCLUSION

This study found that in preclinical AD, overweight and obesity were associated with better verbal memory in women, whereas obesity was associated with worse global cognition among men. Future studies focusing on the mechanism for this relationship may inform sex-specific interventions for AD prevention.

Associations Between Parity and Cognition: Race/Ethnic Differences

BACKGROUND

Race/ethnicity is associated with differences in reproductive history and cognition individually, yet it remains an understudied factor in the relationship between parity and later-life cognition.

OBJECTIVE

To evaluate if the association between parity and cognition differs between racial/ethnic groups.

METHODS

Participants included 778 older, postmenopausal women from the Health and Nutrition Examination Survey (Latina: n = 178, Non-Latino Black [NLB]: n = 169, Non-Latino White [NLW]: n = 431) who self-reported at least one birth. Cognitive outcomes included working memory, learning memory, and verbal fluency. Covariates included age, education, cardiovascular and other reproductive health factors, adult socioeconomic status (SES) and depressive symptoms. We fit a series of linear models to examine a) whether parity was associated with cognitive functioning, b) if this association varied by race/ethnicity through parity by race/ethnicity interactions, and c) individual parity with cognition associations stratified by race/ethnicity.

RESULTS

In the full sample, parity was significantly negatively associated with Digit Symbol Substitution Test (DSST) performance (b = -0.70, p = 0.024) but not Animal Fluency or word-list learning and memory. Tests of race/ethnicity-by-parity interactions were not statistically significant (ps > 0.05). However, stratified analyses by race/ethnicity showed a differential effect of parity on DSST performance, such that parity was significantly negatively associated with DSST performance (b = -1.66, p = 0.007) among Latinas but not in NLWs (b = -0.16, p = 0.74) or NLBs (b = -0.81, p = 0.191).

CONCLUSION

Among Latina, but not NLB or NLW women, greater parity was associated with worse processing speed/executive functioning later in life. Further research is needed to understand the mechanisms driving racial/ethnic differences.

Hospital-based Health Information Technology Infrastructure: Evidence of Reduced Medicare Payments and Racial Disparities Among Patients With ADRD

BACKGROUND

Alzheimer disease and related dementia (ADRD) is one of the most expensive health conditions in the United States. Understanding the potential cost-savings or cost-enhancements of Health Information Technology (HIT) can help policymakers understand the capacity of HIT investment to promote population health and health equity for patients with ADRD.

OBJECTIVES

This study examined access to hospital-based HIT infrastructure and its association with racial and ethnic disparities in Medicare payments for patients with ADRD.

RESEARCH DESIGN

We used the 2017 Medicare Beneficiary Summary File, inpatient claims, and the American Hospital Association Annual Survey. Our study focused on community-dwelling Medicare fee-for-service beneficiaries who were diagnosed with ADRD. Our study focused on hospital-based telehealth-postdischarge (eg, remote patient monitoring) and telehealth-treatment (eg, psychiatric and addiction treatment) services.

RESULTS

Results showed that hospital-based telehealth postdischarge services were associated with significantly higher total Medicare payment and acute inpatient Medicare payment per person per year among patients with ADRD on average. The associations between hospital-based telehealth-treatment services and payments were not significant. However, the association varied by patient's race and ethnicity. The reductions of the payments associated with telehealth postdischarge and treatment services were more pronounced among Black patients with ADRD. Telehealth-treatment services were associated with significant payment reductions among Hispanic patients with ADRD.

CONCLUSION

Results showed that having hospital-based telehealth services might be cost-enhancing at the population level but cost-saving for Black and Hispanic patients with ADRD. Results suggested that personalized HIT services might be necessary to reduce the cost associated with ADRD treatment for racial and ethnic minority groups.

Neighborhood disadvantage and dementia incidence in a cohort of Asian American and non-Latino White older adults in Northern California

INTRODUCTION

Some evidence suggests that neighborhood socioeconomic disadvantage is associated with dementia-related outcomes. However, prior research is predominantly among non-Latino Whites.

METHODS

We evaluated the association between neighborhood disadvantage (Area Deprivation Index [ADI]) and dementia incidence in Asian American (n = 18,103) and non-Latino White (n = 149,385) members of a Northern California integrated health care delivery system aged 60 to 89 at baseline. Race/ethnicity-specific Cox proportional hazards models adjusted for individual-level age, sex, socioeconomic measures, and block group population density estimated hazard ratios (HRs) for dementia.

RESULTS

Among non-Latino Whites, ADI was associated with dementia incidence (most vs. least disadvantaged ADI quintile HR = 1.09, 95% confidence interval [CI] = 1.02-1.15). Among Asian Americans, associations were close to null (e.g., most vs. least disadvantaged ADI quintile HR = 1.01, 95% CI = 0.85-1.21).

DISCUSSION

ADI was associated with dementia incidence among non-Latino Whites but not Asian Americans. Understanding the potentially different mechanisms driving dementia incidence in these groups could inform dementia prevention efforts.