Diversity and disparity in dementia: the impact of ethnoracial differences in Alzheimer disease

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.

The neuropathological landscape of Hispanic and non-Hispanic White decedents with Alzheimer disease

Despite the increasing demographic diversity of the United States' aging population, there remain significant gaps in post-mortem research investigating the ethnoracial heterogeneity in the neuropathological landscape of Alzheimer Disease (AD). Most autopsy-based studies have focused on cohorts of non-Hispanic White decedents (NHWD), with few studies including Hispanic decedents (HD). We aimed to characterize the neuropathologic landscape of AD in NHWD (n = 185) and HD (n = 92) evaluated in research programs across three institutions: University of California San Diego, University of California Davis, and Columbia University. Only persons with a neuropathologic diagnosis of intermediate/high AD determined by NIA Reagan and/or NIA-AA criteria were included. A frequency-balanced random sample without replacement was drawn from the NHWD group using a 2:1 age and sex matching scheme with HD. Four brain areas were evaluated: posterior hippocampus, frontal, temporal, and parietal cortices. Sections were stained with antibodies against Aβ (4G8) and phosphorylated tau (AT8). We compared the distribution and semi-quantitative densities for neurofibrillary tangles (NFTs), neuropil threads, core, diffuse, and neuritic plaques. All evaluations were conducted by an expert blinded to demographics and group status. Wilcoxon's two-sample test revealed higher levels of neuritic plaques in the frontal cortex (p = 0.02) and neuropil threads (p = 0.02) in HD, and higher levels of cored plaques in the temporal cortex in NHWD (p = 0.02). Results from ordinal logistic regression controlling for age, sex, and site of origin were similar. In other evaluated brain regions, semi-quantitative scores of plaques, tangles, and threads did not differ statistically between groups. Our results demonstrate HD may be disproportionately burdened by AD-related pathologies in select anatomic regions, particularly tau deposits. Further research is warranted to understand the contributions of demographic, genetic, and environmental factors to heterogeneous pathological presentations.

Navigating the Complexities of Dementia Care: The Lived Experiences of Black American Family Caregivers

Black American individuals have a higher rate of Alzheimer's disease and related dementias (ADRD) diagnoses compared to other racial/ethnic groups, and their family caregiver population is expected to increase rapidly over the next 2 decades. The current study aimed to explore Black American women's experiences caring for family members with ADRD. An interpretative phenomenology approach was used to gain a deeper understanding of the caregiving experiences of Black American women. Participants in the study were all Black American married women aged 63 to 81 years (mean = 71.3 years, SD = 6.6 years). Key themes that emerged from the study included: (a) Family Care Obligation, (b) Caregiving Journey, (c) Prioritizing Health Concerns, (d) Coping Behaviors, and (e) Support Needs and Challenges. Family caregivers require ongoing support, education, and guidance. Implications for nursing practice include focusing on family assessments, increased education and awareness, and collaboration with interdisciplinary teams to provide the best resources. [Journal of Gerontological Nursing, 49(6), 19-26.].

Moving beyond amyloid and tau to capture the biological heterogeneity of Alzheimer's disease

Alzheimer's disease (AD) manifests along a spectrum of cognitive deficits and levels of neuropathology. Genetic studies support a heterogeneous disease mechanism, with around 70 associated loci to date, implicating several biological processes that mediate risk for AD. Despite this heterogeneity, most experimental systems for testing new therapeutics are not designed to capture the genetically complex drivers of AD risk. In this review, we first provide an overview of those aspects of AD that are largely stereotyped and those that are heterogeneous, and we review the evidence supporting the concept that different subtypes of AD are important to consider in the design of agents for the prevention and treatment of the disease. We then dive into the multifaceted biological domains implicated to date in AD risk, highlighting studies of the diverse genetic drivers of disease. Finally, we explore recent efforts to identify biological subtypes of AD, with an emphasis on the experimental systems and data sets available to support progress in this area.

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.

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.

White matter integrity is associated with cognition and amyloid burden in older adult Koreans along the Alzheimer's disease continuum

BACKGROUND

White matter (WM) microstructural changes in the hippocampal cingulum bundle (CBH) in Alzheimer's disease (AD) have been described in cohorts of largely European ancestry but are lacking in other populations.

METHODS

We assessed the relationship between CBH WM integrity and cognition or amyloid burden in 505 Korean older adults aged ≥55 years, including 276 cognitively normal older adults (CN), 142 mild cognitive impairment (MCI), and 87 AD, recruited as part of the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's disease (KBASE) at Seoul National University.

RESULTS

Compared to CN, AD and MCI subjects showed decreased WM integrity in the bilateral CBH. Cognition, mood, and higher amyloid burden were also associated with poorer WM integrity in the CBH.

CONCLUSION

These findings are consistent with patterns of WM microstructural damage previously reported in non-Hispanic White (NHW) MCI/AD cohorts, reinforcing existing evidence from predominantly NHW cohort studies.

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 4.57mcg/mL) was associated with 1.27 (95%CI: 1.01,1.59) times greater risk of incident dementia than low CRP (<4.57mcg/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.

Recruiting Socially Disconnected Latinos Caring for a Person with Alzheimer's Disease and Related Dementias During the COVID-19 Pandemic: Lessons Learned

OBJECTIVES

The purpose of this article is to present conceptual and methodological challenges to recruitment strategies in enrolling socially disconnected middle-aged and older Latino caregivers of a loved one with Alzheimer's disease and related dementias (ADRD).

METHODS

Middle-aged and older Latino ADRD caregivers were recruited into two early stage, intervention development studies during the COVID-19 pandemic via online or in-person methods. Recruitment criteria included Latino ADRD caregivers over the age of 40 reporting elevated loneliness on the UCLA 3-item Loneliness Scale (LS) during screening.

RESULTS

Middle-aged, Latino caregivers were recruited predominantly from online methods whereas older caregivers were mostly recruited from in-person methods. We report challenges identifying socially disconnected Latino caregivers using the UCLA 3-item LS.

CONCLUSIONS

Our findings support previously reported disparities in recruitment by age and language and suggest further methodological considerations to assess social disconnection among Latino caregivers. We discuss recommendations to overcome these challenges in future research.

CLINICAL IMPLICATIONS

Socially disconnected Latino ADRD caregivers have an elevated risk for poor mental health outcomes. Successful recruitment of this population in clinical research will ensure the development of targeted and culturally sensitive interventions to improve the mental health and overall well-being of this marginalized group.

Alzheimer's disease medication use and adherence patterns by race and ethnicity

BACKGROUND

We examined racial and ethnic differences in medication use for a representative US population of patients with Alzheimer's disease and related dementias (ADRD).

METHODS

We examined cholinesterase inhibitors and memantine initiation, non-adherence, and discontinuation by race and ethnicity, using data from the 2000-2016 Health and Retirement Study linked with Medicare and Medicaid claims.

RESULTS

Among newly diagnosed ADRD patients (n = 1299), 26% filled an ADRD prescription ≤90 days and 36% ≤365 days after diagnosis. Among individuals initiating ADRD-targeted treatment (n = 1343), 44% were non-adherent and 24% discontinued the medication during the year after treatment initiation. Non-Hispanic Blacks were more likely than Whites to not adhere to ADRD medication therapy (odds ratio: 1.50 [95% confidence interval: 1.07-2.09]).

DISCUSSION

Initiation of ADRD-targeted medications did not vary by ethnoracial group, but non-Hispanic Blacks had lower adherence than Whites. ADRD medication non-adherence and discontinuation were substantial and may relate to cost and access to care.

HIGHLIGHTS

Initiation of anti-dementia medications among newly diagnosed Alzheimer's disease and related dementias (ADRD) patients was low in all ethnoracial groups. ADRD medication non-adherence and discontinuation were substantial and may relate to cost and access to care. Compared to Whites, Blacks and Hispanics had lower use, poorer treatment adherence, and more frequent discontinuation of ADRD medication, but when controlling for disease severity and socioeconomic factors, racial disparities diminish. Our findings demonstrate the importance of adjusting for socioeconomic characteristics and disease severity when studying medication use and adherence in ADRD patients.

Supervised, Self-Administered Tablet-Based Cognitive Assessment in Neurodegenerative Disorders and Stroke

INTRODUCTION

As the population ages, the prevalence of cognitive impairment is expanding. Given the recent pandemic, there is a need for remote testing modalities to assess cognitive deficits in individuals with neurological disorders. Self-administered, remote, tablet-based cognitive assessments would be clinically valuable if they can detect and classify cognitive deficits as effectively as traditional in-person neuropsychological testing.

METHODS

We tested whether the Miro application, a tablet-based neurocognitive platform, measured the same cognitive domains as traditional pencil-and-paper neuropsychological tests. Seventy-nine patients were recruited and then randomized to either undergo pencil-and-paper or tablet testing first. Twenty-nine age-matched healthy controls completed the tablet-based assessments. We identified Pearson correlations between Miro tablet-based modules and corresponding neuropsychological tests in patients and compared scores of patients with neurological disorders with those of healthy controls using t tests.

RESULTS

Statistically significant Pearson correlations between the neuropsychological tests and their tablet equivalents were found for all domains with moderate (r > 0.3) or strong (r > 0.7) correlations in 16 of 17 tests (p < 0.05). All tablet-based subtests differentiated healthy controls from neurologically impaired patients by t tests except for the spatial span forward and finger tapping modules. Participants reported enjoyment of the tablet-based testing, denied that it provoked anxiety, and noted no preference between modalities.

CONCLUSIONS

This tablet-based application was found to be widely acceptable to participants. This study supports the validity of these tablet-based assessments in the differentiation of healthy controls from patients with neurocognitive deficits in a variety of cognitive domains and across multiple neurological disease etiologies.

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.

On gaps of clinical diagnosis of dementia subtypes: A study of Alzheimer's disease and Lewy body disease

Introduction

Alzheimer's disease (AD) and Lewy body disease (LBD) are the two most common neurodegenerative dementias and can occur in combination (AD+LBD). Due to overlapping biomarkers and symptoms, clinical differentiation of these subtypes could be difficult. However, it is unclear how the magnitude of diagnostic uncertainty varies across dementia spectra and demographic variables. We aimed to compare clinical diagnosis and post-mortem autopsy-confirmed pathological results to assess the clinical subtype diagnosis quality across these factors.

Methods

We studied data of 1,920 participants recorded by the National Alzheimer's Coordinating Center from 2005 to 2019. Selection criteria included autopsy-based neuropathological assessments for AD and LBD, and the initial visit with Clinical Dementia Rating (CDR) stage of normal, mild cognitive impairment, or mild dementia. Longitudinally, we analyzed the first visit at each subsequent CDR stage. This analysis included positive predictive values, specificity, sensitivity and false negative rates of clinical diagnosis, as well as disparities by sex, race, age, and education. If autopsy-confirmed AD and/or LBD was missed in the clinic, the alternative clinical diagnosis was analyzed.

Findings

In our findings, clinical diagnosis of AD+LBD had poor sensitivities. Over 61% of participants with autopsy-confirmed AD+LBD were diagnosed clinically as AD. Clinical diagnosis of AD had a low sensitivity at the early dementia stage and low specificities at all stages. Among participants diagnosed as AD in the clinic, over 32% had concurrent LBD neuropathology at autopsy. Among participants diagnosed as LBD, 32% to 54% revealed concurrent autopsy-confirmed AD pathology. When three subtypes were missed by clinicians, "No cognitive impairment" and "primary progressive aphasia or behavioral variant frontotemporal dementia" were the leading primary etiologic clinical diagnoses. With increasing dementia stages, the clinical diagnosis accuracy of black participants became significantly worse than other races, and diagnosis quality significantly improved for males but not females.

Discussion

These findings demonstrate that clinical diagnosis of AD, LBD, and AD+LBD are inaccurate and suffer from significant disparities on race and sex. They provide important implications for clinical management, anticipatory guidance, trial enrollment and applicability of potential therapies for AD, and promote research into better biomarker-based assessment of LBD pathology.

2023 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease, including prevalence and incidence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report examines the patient journey from awareness of cognitive changes to potential treatment with drugs that change the underlying biology of Alzheimer's. An estimated 6.7 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060 barring the development of medical breakthroughs to prevent, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, and Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated by the COVID-19 pandemic in 2020 and 2021. More than 11 million family members and other unpaid caregivers provided an estimated 18 billion hours of care to people with Alzheimer's or other dementias in 2022. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $339.5 billion in 2022. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the paid health care workforce are involved in diagnosing, treating and caring for people with dementia. In recent years, however, a shortage of such workers has developed in the United States. This shortage - brought about, in part, by COVID-19 - has occurred at a time when more members of the dementia care workforce are needed. Therefore, programs will be needed to attract workers and better train health care teams. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2023 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $345 billion. The Special Report examines whether there will be sufficient numbers of physician specialists to provide Alzheimer's care and treatment now that two drugs are available that change the underlying biology of Alzheimer's disease.

Apolipoprotein E (APOE) genotype, dementia, and memory performance among Caribbean Hispanic versus US populations

INTRODUCTION

Apolipoprotein E (APOE) is considered the major susceptibility gene for developing Alzheimer's disease. However, the strength of this risk factor is not well established across diverse Hispanic populations.

METHODS

We investigated the associations among APOE genotype, dementia prevalence, and memory performance (immediate and delayed recall scores) in Caribbean Hispanics (CH), African Americans (AA), Hispanic Americans (HA) and non-Hispanic White Americans (NHW). Multivariable logistic regressions and negative binomial regressions were used to examine these associations by subsample.

RESULTS

Our final dataset included 13,516 participants (5198 men, 8318 women) across all subsamples, with a mean age of 74.8 years. Prevalence of APOE ε4 allele was similar in CHs, HAs, and NHWs (21.8%-25.4%), but was substantially higher in AAs (33.6%; P < 0.001). APOE ε4 carriers had higher dementia prevalence across all groups.

DISCUSSION

APOE ε4 was similarly associated with increased relative risk of dementia and lower memory performance in all subsamples.

Race and Ethnicity in Lewy Body Dementia: A Narrative Review

Lewy body dementia is the third most common and costliest type of dementia. It is an umbrella term for dementia with Lewy bodies and Parkinson's disease dementia, both of which place a substantial burden on the person and society. Recent findings outline ethnoracial differences in dementia risk. Delayed and misdiagnosis across ethnoracial groups contribute to higher levels of burden. In this context, we aimed to summarize current knowledge, gaps, and unmet needs relating to race and ethnicity in Lewy body dementia. In this narrative review, we provide an overview of studies on Lewy body dementia focusing on differences across ethnoracial groups and outline several recommendations for future studies. The majority of the findings comparing different ethnoracial groups were from North American sites. There were no differences in clinical prevalence and progression across ethnoracial groups. Compared to people identifying as non-Hispanic White, co-pathologies were more common and clinical diagnostic accuracy was lower for people identifying as Black. Co-morbidities (e.g., diabetes, hypertension) were more common and medication use rates (e.g., antidepressants, antiparkinsonian agents) were lower for people identifying as Black or Hispanic compared to people identifying as White. More than 90% of clinical trial participants identified as non-Hispanic White. Despite increasing efforts to overcome disparities in Alzheimer's disease and related dementias, inclusion of individuals from minoritized communities in Lewy body dementia studies continues to be limited and the findings are inconclusive. Representation of diverse populations is crucial to improve the diagnostic and therapeutic efforts in Lewy body dementia.

Let's Not Repeat History's Mistakes: Two Cautions to Scientists on the Use of Race in Alzheimer's Disease and Alzheimer's Disease Related Dementias Research

Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD) research has advanced gene and biomarker technologies to aid identification of individuals at risk for dementia. This innovation is a lynchpin in development of disease-modifying therapies. The emerging science could transform outcomes for patients and families. However, current limitations in the racial representation and inclusion of racial diversity in research limits the relevance of these technologies: AD/ADRD research cohorts used to define biomarker cutoffs are mostly White, despite clinical and epidemiologic research that shows Black populations are among those experiencing the greatest burdens of AD/ADRD. White cohorts alone are insufficient to characterize heterogeneity in disease and in life experiences that can alter AD/ADRD's courses. The National Institute on Aging (NIA) has called for increased racial diversity in AD/ADRD research. While scientists are working to implement NIA's plan to build more diverse research cohorts, they are also seeking out opportunities to consider race in AD/ADRD research. Recently, scientists have posed two ways of including race in AD/ADRD research: ancestry-based verification of race and race-based adjustment of biomarker test results. Both warrant careful examination for how they are impacting AD/ADRD science with respect to specific study objectives and the broader mission of the field. If these research methods are not grounded in pursuit of equity and justice, biases they introduce into AD/ADRD science could perpetuate, or even worsen, disparities in AD/ADRD research and care.

Resilience resources may buffer some middle-aged and older Black Americans from memory decline despite experiencing discrimination

RATIONALE

Experiences of discrimination have been associated with poorer episodic memory in Black Americans. However, resilience resources at multiple levels (individual, social, and endowed) may act as a buffer to protect future memory decline, especially in the face of discrimination.

OBJECTIVE

Using longitudinal data from the 2006-2016 Health and Retirement Study (N = 1862), we tested whether Black Americans aged 50 and older would show different trajectories of episodic memory depending on their reported experiences of discrimination (everyday and major lifetime) and resilience resources.

METHODS

Analyses were conducted in three steps: (1) joint latent cluster mixed modeling (JLCMM) to estimate the number of classes, (2) barycentric discriminant analyses (BADA) to model the combined influence of discrimination and resilience resources between each memory class, and (3) multinomial regression analyses to explore interactions between discrimination and resilience resources.

RESULTS

JLCMM resulted in three memory classes that differentiated baseline from longitudinal memory performance: "High Decliners," "Low Decliners," and "Low Stable." Two independent patterns described the relationships between the three classes in the context of discrimination and resilience resources. First, compared with High Decliners, the two lower baseline memory classes (Low Decliners and Low Stable) reported more everyday discrimination and lower individual and endowed resilience resources. Second, although the Low Stable class did not report different levels of discrimination, they had more social resilience resources (greater social support and more social contact) than both declining classes.

CONCLUSIONS

Black Americans in later life have heterogeneous patterns of memory trajectories as demonstrated by the three memory classes identified. Those with lower baseline memory experienced more everyday discrimination and had fewer resilience resources compared to those with high baseline performance (High Decliners). Greater social resilience resources were associated with maintained episodic memory over time in Black Americans.

Perceptions of Research Participation among a Sample of Florida Residents Aged 50 and Over Reporting Dementia

As the population ages, the prevalence of dementia will increase. More research is needed; however, low rates of research participation, especially by older adults, hinder progress. Data came from HealthStreet, a University of Florida community engagement program in which community health workers assess community members for their health conditions. Adults 50 and over were included in these analyses; their perceptions of health research studies were assessed. Our sample had an average age of 60.5 years and 4.3% reported dementia (n = 4,881). Overall, older adults reported a high willingness to participate in research. Individuals who reported dementia had 0.64 times the odds of reporting willingness to participate in a research study that required an overnight stay, compared to those who did not report dementia (95% CI: 0.45-0.89). We report on willingness to participate in research in a more granular basis than has been previously done. Community members reporting dementia, compared to those without, were as or more likely to desire future participation in health research. However, barriers to participation remain and must be addressed.

Education Mediates Racial Disparities in Cognitive Impairment Among Older Adults With Schizophrenia

OBJECTIVES

In the general population, the construct of race is associated with disparities in cognitive aging. There are notable racial group disparities and inequities among people living with schizophrenia (PLWSz). Despite the salience of the construct of race in schizophrenia, there remains a knowledge gap about racial disparities in cognitive impairment among older adults in this vulnerable population. Our study uses mediation analysis to examine racial disparities in cognitive impairment among older adults with schizophrenia.

METHODS

We assess global cognition in PLWSz over age 55 with the Measurement and Treatment Research to Improve Cognition in Schizophrenia cognitive test battery in our "all-comer" sample (N = 64). The primary exposure is self-reported racial group. We examine mediation of cognitive impairment through educational attainment, adjusting for psychiatric illness severity, history of substance use, and vascular risk factors.

RESULTS

There was a Black/non-Black group racial disparity in global cognitive score (-2.8, 95% CI: -4.4, -1.3) after adjusting for confounding and interaction. This disparity was significantly mediated by years of education.

CONCLUSIONS

There are notable racial disparities in cognitive impairment among older adults with schizophrenia; however, differences in cognitive scores between racial groups are mediated by level of education.

CLINICAL IMPLICATIONS

Social determinants of health, particularly educational attainment, are important risk factors for cognitive impairment in PLWSz and should be considered by clinicians. Early screening and assessment of cognitive symptoms is essential to addressing health disparities/inequalities among older adults living with schizophrenia.

ABBREVIATIONS CDE

Controlled Direct EffectsHIV: Human Immunodeficiency VirusMATRICS: Measurement and Treatment Research to Improve Cognition in SchizophreniaMCCB: MATRICS Consensus Cognitive BatteryMTE: Marginal Total EffectsNDE: Natural Direct EffectsPANSS: Positive and Negative Symptom ScalePLWSz: People with schizophrenia.

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.

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.

Dementia Attributable Healthcare Utilizations in the Caribbean versus United States

BACKGROUND

Despite the high burden of Alzheimer's disease and other dementias among the Hispanic population worldwide, little is known about how dementia affects healthcare utilizations among this population outside of the US, in particular among those in the Caribbean region.

OBJECTIVE

This study examines healthcare utilization associated with Alzheimer's disease and other dementias among older adults in the Caribbean as compared to the US.

METHODS

We conducted harmonized analyses of two population-based surveys, the 10/66 Dementia Group Research data collected in Dominican Republic, Cuba, and Puerto Rico, and the US-based Health and Retirement Study. We examined changes in hospital nights and physician visits in response to incident and ongoing dementias.

RESULTS

Incident dementia significantly increased the risk of hospitalization and number of hospital nights in both populations. Ongoing dementia increased the risk of hospitalization and hospital nights in the US, with imprecise estimates for the Caribbean. The number of physician visits was elevated in the US but not in the Caribbean.

CONCLUSIONS

The concentration of increased healthcare utilization on hospital care and among patients with incident dementia suggests an opportunity for improved outpatient management of new and existing dementia patients in the Caribbean.

Risks and Benefits of Clinical Diagnosis Around the Time of Dementia Onset

Diagnostic delay in dementia is common in the U.S. Drivers of diagnostic delay are poorly understood, but appear related to misconceptions about dementia, stigma, concerns about autonomy, the nature of the diagnostic process, and provider-related factors. There is little quantitative evidence underlying cited risks and benefits of receiving a diagnosis around the time of dementia onset, including impacts on physical health, impacts on mental health, care partner interactions, costs of care, increased time for care planning, or earlier access to treatment. While various groups continue to push for reductions in diagnostic delay, realization of benefits and mitigation of harms will require new research on potential benefits and harms. Workforce and resource constraints, coupled with the expected growth in the number of persons living with dementia, may be a barrier to realization of potential benefits and mitigation of identified harms, which will require adequate access to providers, services, and supports.

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.

The Impact of Educational Attainment and Income on Long-Term Care for Persons with Alzheimer's Disease and Other Dementias: A Swedish Nationwide Study

BACKGROUND

Long-term care improves independence and quality of life of persons with dementia (PWD). The influence of socioeconomic status on access to long-term care was understudied.

OBJECTIVE

To explore the socioeconomic disparity in long-term care for PWD.

METHODS

This registry-based study included 14,786 PWD, registered in the Swedish registry for cognitive and dementia disorders (2014-2016). Education and income, two traditional socioeconomic indicators, were the main exposure. Outcomes were any kind of long-term care, specific types of long-term care (home care, institutional care), and the monthly average hours of home care. The association between outcomes and socioeconomic status was examined with zero-inflated negative binomial regression and binary logistic regression.

RESULTS

PWD with compulsory education had lower likelihood of receiving any kind of long-term care (OR 0.80, 95% CI 0.68-0.93), or home care (OR 0.83, 95% CI 0.70-0.97), compared to individuals with university degrees. Their monthly average hours of home care were 0.70 times (95% CI 0.59-0.82) lower than those of persons with university degrees. There was no significant association between education and the receipt of institutional care. Stratifying on persons with Alzheimer's disease showed significant association between lower education and any kind of long-term care, and between income and the hours of home care.

CONCLUSIONS

Socioeconomic inequalities in long-term care existed in this study population. Lower-educated PWD were less likely to acquire general long-term care, home care and had lower hours of home care, compared to their higher-educated counterparts. Income was not significantly associated with the receipt of long-term care.

The Moderating Role of Race and Ethnicity in the Association Between Cognitive Performance and Functional Abilities in Later Life

This study examined ethnic/racial influences on the relationship of cognitive performance and functional abilities of 2,713 older individuals from the National Health and Nutrition Examination Survey (NHANES). Functional domains included activities of daily living (ADL), instrumental ADL, and leisure and social activities. In adjusted logistic regression models, low cognitive performance as assessed by the Digit Symbol Substitution Test was found significantly associated with functional limitation in each domain. However, moderation analysis revealed that being Hispanic and non-Hispanic Black may weaken this association demonstrating protective effects of underrepresented ethnic/racial status. Future studies should investigate perceived discrimination and resilience.

Overactive Bladder and Cognitive Impairment: The American Urogynecologic Society and Pelvic Floor Disorders Research Foundation State-of-the-Science Conference Summary Report

IMPORTANCE

Overactive bladder (OAB) is prevalent in older adults in whom management is complicated by comorbidities and greater vulnerability to the cognitive effects of antimuscarinic medications.

OBJECTIVES

The aim of this study is to provide a comprehensive evidence-based summary of the 2021 State-of-the-Science (SOS) conference and a multidisciplinary expert literature review on OAB and cognitive impairment.

STUDY DESIGN

The American Urogynecologic Society and the Pelvic Floor Disorders Research Foundation convened a 3-day collaborative conference. Experts from multidisciplinary fields examined cognitive function, higher neural control of the OAB patient, risk factors for cognitive impairment in older patients, cognitive effects of antimuscarinic medications for OAB treatment, OAB phenotyping, conservative and advanced OAB therapies, and the need for a multidisciplinary approach to person-centered treatment. Translational topics included the blood-brain barrier, purine metabolome, mechanotransduction, and gene therapy for OAB targets.

RESULTS

Research surrounding OAB treatment efficacy in cognitively impaired individuals is limited. Short- and long-term outcomes regarding antimuscarinic effects on cognition are mixed; however, greater anticholinergic burden and duration of use influence risk. Oxybutynin is most consistently associated with negative cognitive effects in short-term, prospective studies. Although data are limited, beta-adrenergic agonists do not appear to confer the same cognitive risk.

CONCLUSIONS

The 2021 SOS summary report provides a comprehensive review of the fundamental, translational, and clinical research on OAB with emphasis on cognitive impairment risks to antimuscarinic medications. Duration of use and antimuscarinic type, specifically oxybutynin when examining OAB treatments, appears to have the most cognitive impact; however, conclusions are limited by the primarily cognitively intact population studied. Given current evidence, it appears prudent to minimize anticholinergic burden by emphasizing nonantimuscarinic therapeutic regimens in the older population and/or those with cognitive impairment.

Social determinants of memory change: A three-year follow-up of the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVES

Changes in memory can interfere with activities of daily living and may be indicative of serious health concerns such as mild cognitive impairment or dementia. Risk factors for cognitive decline and dementia have been shown to cluster around inequalities, suggesting that minority groups may be at an increased risk for cognitive decline. We sought to clarify the relationship between social determinants and change in memory function over a 3-year follow-up period, after accounting for demographic and health variables.

METHODS

We used baseline and first follow-up data from the Canadian Longitudinal Study on Aging (CLSA). Our primary analysis consisted of a multivariable linear regression model (n = 30,475). Demographic, health, education and occupation, social support, social identity, and social positioning variables (predictors) were measured at baseline. We computed a reliable change index (outcome) using the Rey Auditory Verbal Learning Test (RAVLT).

RESULTS

Older age and some health considerations (e.g., higher body mass index, low hearing) were associated with a greater decline in memory over the three-year period. In contrast, some physical activity and better self-rated general health were associated with improvements in memory. Having a hobby and better perceived social standing were associated with greater memory improvement. Social identities who experience minority stress (sexual orientation, gender identity, and race) did not predict change in memory.

DISCUSSION

Altogether, these results contribute to a growing body of evidence that points to older members of minoritized communities exhibiting initial differences in cognitive functioning (i.e., cross-sectional differences) but not more rapid cognitive aging.

Access to care by Medicare beneficiaries in the U.S. with diabetes and multiple chronic conditions during the COVID-19 pandemic

OBJECTIVE

Determine characteristics of Medicare beneficiaries with diabetes and multiple chronic conditions (MCC) associated with being unable to obtain medical services during COVID-19.

RESEARCH DESIGN AND METHODS

Retrospective cohort study of data from COVID-19 Supplements of Medicare Current Beneficiary Surveys administered in Summer (N = 11,114, unweighted) and Fall (N = 9686, unweighted) 2020, and Winter 2021 (N = 11,107, unweighted). Binary logistic regression was used to model for adjusted odds of self-reports of being unable to access different types of care.

RESULTS

In three time periods from March 2020 through March/April 2021 beneficiaries with diabetes plus MCC combinations reported being unable to get medical care, compared to beneficiaries with diabetes alone. Notably, patterns persisted at the 12-month mark with beneficiaries with diabetes plus cancer (OR = 1.24), and diabetes plus cancer/stroke (OR = 2.53) experiencing increased odds of being unable to get care because of COVID-19, compared to beneficiaries with diabetes alone. By March/April 2021 beneficiaries with diabetes plus COPD (OR = 1.08), diabetes plus stroke (OR = 1.49), and diabetes plus Alzheimer's (OR = 1.09) experienced increased odds of being unable to get treatment for ongoing conditions. Beneficiaries with diabetes plus Alzheimer's (OR = 1.40) also experienced increased odds of being unable to get a regular check-up 12 months into the pandemic. Finally, members of racial/ethnic minority groups experienced increased odds of being unable to obtain services at various times during the pandemic compared to non-Hispanic Whites, with increased odds persisting at 12 months for non-Hispanic Blacks and Hispanics.

CONCLUSIONS

Beneficiaries with MCC, and minorities, experienced increased odds of being unable to obtain some services during COVID-19, even when controlling for similar diabetes and MCC combinations. Work remains for providers and public health systems to dismantle and reimagine systems to provide equitable access to care.

Comparison of Computerised and Pencil-and-Paper Neuropsychological Assessments in Older Culturally and Linguistically Diverse Australians

OBJECTIVES

Computerised neuropsychological assessments (CNAs) are proposed as an alternative method of assessing cognition to traditional pencil-and-paper assessment (PnPA), which are considered the "gold standard" for diagnosing dementia. However, limited research has been conducted with culturally and linguistically diverse (CALD) individuals. This study investigated the suitability of PnPAs and CNAs for measuring cognitive performance in a heterogenous sample of older, Australian CALD English-speakers compared to a native English-speaking background (ESB) sample.

METHODS

Participants were 1037 community-dwelling individuals aged 70-90 years without a dementia diagnosis from the Sydney Memory and Ageing Study (873 ESB, 164 CALD). Differences in the level and pattern of cognitive performance in the CALD group were compared to the ESB group on a newly developed CNA and a comprehensive PnPA in English, controlling for covariates. Multiple hierarchical regression was used to identify the extent to which linguistic and acculturation variables explained performance variance.

RESULTS

CALD participants' performance was consistently poorer than ESB participants on both PnPA and CNA, and more so on PnPA than CNA, controlling for socio-demographic and health factors. Linguistic and acculturation variables together explained approximately 20% and 25% of CALD performance on PnPA and CNA respectively, above demographics and self-reported computer use.

CONCLUSIONS

Performances of CALD and ESB groups differed more on PnPAs than CNAs, but caution is needed in concluding that CNAs are more culturally-appropriate for assessing cognitive decline in older CALD individuals. Our findings extend current literature by confirming the influence of linguistic and acculturation variables on cognitive assessment outcomes for older CALD Australians.

An HIT-Supported Care Coordination Framework for Reducing Structural Racism and Discrimination for Patients With ADRD

Black and Latinx Americans are disproportionately at greater risk for having Alzheimer's disease and related dementias (ADRD) than White Americans. Such differences in risk for ADRD are arguably explained through health disparities, social inequities, and historical policies. Structural racism and discrimination (SRD), defined as "macro-level conditions that limit opportunities, resources, and well-being of less privileged groups," have been linked with common comorbidities of ADRD, including hypertension, obesity, diabetes, depression. Given the historical impact of SRD-including discriminatory housing policies resulting in racial residential segregation that has been shown to limit access to education, employment, and healthcare-Black and Latinx populations with ADRD are directly or indirectly negatively affected by SRD in terms of access, quality and cost for healthcare. Emerging studies have brought to light the value of structural-level hospital and public health collaboration on care coordination for improving healthcare quality and access, and thus could serve as a macro-level mechanism for addressing disparities for minoritized racial and ethnic populations with ADRD. This paper presents a conceptual framework delineating how care coordination can successfully be achieved through health information technology (HIT) systems and ultimately address SRD. To address health inequities, it is therefore critical that policy initiatives invest in HIT capacities and infrastructures to promote care coordination, identify patient needs and preferences, and promote engagement of patients with ADRD and their caregivers.

Exploring community knowledge, attitudes and perceptions of Alzheimer's Disease/Alzheimer's Disease-Related Dementias and healthy ageing in Asian American, Native Hawaiian and Pacific Islanders

Alzheimer's disease and related dementias (AD/ADRD) disparities exist in the rapidly growing and extremely heterogeneous Asian American and Native Hawaiian and Pacific Islander (NH/PI) ageing populations in the United States. Limited community-clinical resources supporting culturally competent and timely diagnosis exacerbate barriers to existing care services in these populations. Community-based participatory research or community-engaged research are proven community-academic research approaches that can support the development and implementation of community-focused programmes to maximise community benefit. The NYU Center for the Study of Asian American Health engaged our national and local community partners to gain a deeper understanding of AD/ADRD in this diverse and growing population, to develop a strategic community-engaged research agenda to understand, address and reduce AD/ADRD disparities among Asian American and NH/PI communities. Findings from an initial scoping review identified significant research gaps. We conducted a series of key informant interviews (n = 11) and a modified Delphi survey (n = 14) with Asian American and NH/PI community leaders and older adult service providers followed by a facilitated group discussion of survey findings to gain consensus on key priority research areas identified in the literature and to determine culturally and contextually appropriate approaches to support AD/ADRD prevention, early identification and treatment in Asian American and NH/PI communities. Future research and health education should focus on raising Asian American and NH/PI basic individual- and community-level awareness about AD/ADRD and leveraging existing community assets to integrate effective engagement strategies to access AD/ADRD services within the healthcare system.

Global and local ancestry modulate APOE association with Alzheimer's neuropathology and cognitive outcomes in an admixed sample

Dementia is more prevalent in Blacks than in Whites, likely due to a combination of environmental and biological factors. Paradoxically, clinical studies suggest an attenuation of APOE ε4 risk of dementia in African ancestry (AFR), but a dearth of neuropathological data preclude the interpretation of the biological factors underlying these findings, including the association between APOE ε4 risk and Alzheimer's disease (AD) pathology, the most frequent cause of dementia. We investigated the interaction between African ancestry, AD-related neuropathology, APOE genotype, and functional cognition in a postmortem sample of 400 individuals with a range of AD pathology severity and lack of comorbid neuropathology from a cohort of community-dwelling, admixed Brazilians. Increasing proportions of African ancestry (AFR) correlated with a lower burden of neuritic plaques (NP). However, for individuals with a severe burden of NP and neurofibrillary tangles (NFT), AFR proportion was associated with worse Clinical Dementia Rating sum of boxes (CDR-SOB). Among APOE ε4 carriers, the association between AFR proportion and CDR-SOB disappeared. APOE local ancestry inference of a subset of 309 individuals revealed that, in APOE ε4 noncarriers, non-European APOE background correlated with lower NP burden and, also, worse cognitive outcomes than European APOE when adjusting by NP burden. Finally, APOE ε4 was associated with worse AD neuropathological burden only in a European APOE background. APOE genotype and its association with AD neuropathology and clinical pattern are highly influenced by ancestry, with AFR associated with lower NP burden and attenuated APOE ε4 risk compared to European ancestry.

Racial and Ethnic Differences in Amyloid PET Positivity in Individuals With Mild Cognitive Impairment or Dementia: A Secondary Analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Cohort Study

Importance

Racial and ethnic groups with higher rates of clinical Alzheimer disease (AD) are underrepresented in studies of AD biomarkers, including amyloid positron emission tomography (PET).

Objective

To compare amyloid PET positivity among a diverse cohort of individuals with mild cognitive impairment (MCI) or dementia.

Design, Setting, and Participants

Secondary analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS), a single-arm multisite cohort study of Medicare beneficiaries who met appropriate-use criteria for amyloid PET imaging between February 2016 and September 2017 with follow-up through January 2018. Data were analyzed between April 2020 and January 2022. This study used 2 approaches: the McNemar test to compare amyloid PET positivity proportions between matched racial and ethnic groups and multivariable logistic regression to assess the odds of having a positive amyloid PET scan. IDEAS enrolled participants at 595 US dementia specialist practices. A total of 21 949 were enrolled and 4842 (22%) were excluded from the present analysis due to protocol violations, not receiving an amyloid PET scan, not having a positive or negative scan, or because of small numbers in some subgroups.

Exposures

In the IDEAS study, participants underwent a single amyloid PET scan.

Main Outcomes and Measures

The main outcomes were amyloid PET positivity proportions and odds.

Results

Data from 17 107 individuals (321 Asian, 635 Black, 829 Hispanic, and 15 322 White) with MCI or dementia and amyloid PET were analyzed between April 2020 and January 2022. The median (range) age of participants was 75 (65-105) years; 8769 participants (51.3%) were female and 8338 (48.7%) were male. In the optimal 1:1 matching analysis (n = 3154), White participants had a greater proportion of positive amyloid PET scans compared with Asian participants (181 of 313; 57.8%; 95% CI, 52.3-63.2 vs 142 of 313; 45.4%; 95% CI, 39.9-50.9, respectively; P = .001) and Hispanic participants (482 of 780; 61.8%; 95% CI, 58.3-65.1 vs 425 of 780; 54.5%; 95% CI, 51.0-58.0, respectively; P = .003) but not Black participants (359 of 615; 58.4%; 95% CI, 54.4-62.2 vs 333 of 615; 54.1%; 95% CI, 50.2-58.0, respectively; P = .13). In the adjusted model, the odds of having a positive amyloid PET scan were lower for Asian participants (odds ratio [OR], 0.47; 95% CI, 0.37-0.59; P < .001), Black participants (OR, 0.71; 95% CI, 0.60-0.84; P < .001), and Hispanic participants (OR, 0.68; 95% CI, 0.59-0.79; P < .001) compared with White participants.

Conclusions and Relevance

Racial and ethnic differences found in amyloid PET positivity among individuals with MCI and dementia in this study may indicate differences in underlying etiology of cognitive impairment and guide future treatment and prevention approaches.

Observational study of patient characteristics associated with a timely diagnosis of dementia and mild cognitive impairment without dementia

BACKGROUND

Timely diagnosis of cognitive impairment is a key goal of the National Plan to Address Alzheimer's Disease, but studies of factors associated with a timely diagnosis are limited.

OBJECTIVE

To identify patient characteristics associated with a timely diagnosis of dementia and mild cognitive impairment (MCI).

DESIGN

Retrospective observational study using survey data from the Health and Retirement Study (HRS) from 1995-2016 (interview waves 3-13).

PARTICIPANTS

4,760 respondents with incident dementia and 1,864 with incident MCI identified using longitudinal measures of cognitive functioning.

MAIN MEASURES

Timely or delayed diagnosis based on the timing of a self or proxy report of a healthcare provider diagnosis in relation to respondents first dementia or MCI-qualifying cognitive score, sociodemographic characteristics, health status, health care utilization, insurance provider, and year of first qualifying score.

KEY RESULTS

Only 26.0% of the 4,760 respondents with incident dementia and 11.4% of the 1,864 respondents with incident MCI received a timely diagnosis. Non-Hispanic Black respondents and respondents with less than a college degree were significantly less likely to receive a timely diagnosis of either dementia or MCI than Non-Hispanic White respondents (dementia odds ratio (OR): 0.61, 95% CI: 0.50, 0.75; MCI OR: 0.40, 95% CI: 0.23, 0.70) and those with a college degree (dementia OR for less than high school degree: 0.30, 95% CI: 0.23, 0.38; MCI OR: 0.36, 95% CI: 0.22, 0.60). Respondents that lived alone were also less likely to receive a timely diagnosis of dementia (OR: 0.69, 95% CI: 0.59, 0.81), though not MCI. Timely diagnosis of both conditions increased over time.

CONCLUSIONS

Targeting resources for timely diagnosis of cognitive impairment to individuals from racial and ethnic minorities, lower educational attainment, and living alone may improve detection and reduce disparities around timely diagnosis of dementia and MCI.

Association of Healthy Lifestyles With Risk of Alzheimer Disease and Related Dementias in Low-Income Black and White Americans

BACKGROUND AND OBJECTIVES

Although the importance of healthy lifestyles for preventing Alzheimer disease and related dementias (ADRD) has been recognized, epidemiologic evidence remains limited for non-White or low-income individuals who bear disproportionate burdens of ADRD. This population-based cohort study aims to investigate associations of lifestyle factors, individually and together, with the risk of ADRD among socioeconomically disadvantaged Americans.

METHODS

In the Southern Community Cohort Study, comprising two-thirds self-reported Black and primarily low-income Americans, we identified incident ADRD using claims data among participants enrolled in Medicare for at least 12 consecutive months after age 65 years. Five lifestyle factors-tobacco smoking, alcohol consumption, leisure-time physical activity (LTPA), sleep hours, and diet quality-were each scored 0 (unhealthy), 1 (intermediate), or 2 (healthy) based on the health guidelines. A composite lifestyle score was created by summing all scores. Cox regression was used to estimate hazard ratios (HRs, 95% CIs) for incident ADRD, treating death as a competing risk.

RESULTS

We identified 1,694 patients with newly diagnosed ADRD among 17,209 participants during a median follow-up of 4.0 years in claims data; the mean age at ADRD diagnosis was 74.0 years. Healthy lifestyles were individually associated with an 11%-25% reduced risk of ADRD: multivariable-adjusted HR (95% CI) was 0.87 (0.76-0.99) for never vs current smoking, 0.81 (0.72-0.92) for low-to-moderate vs no alcohol consumption, 0.89 (0.77-1.03) for ≥150 minutes of moderate or ≥75 minutes of vigorous LTPA each week vs none, 0.75 (0.64-0.87) for 7-9 hours vs >9 hours of sleep, and 0.85 (0.75-0.96) for the highest vs lowest tertiles of the Healthy Eating Index. The composite lifestyle score showed a dose-response association with up to 36% reduced risk of ADRD: multivariable-adjusted HRs (95% CIs) across quartiles were 1 (ref), 0.88 (0.77-0.99), 0.79 (0.70-0.90), and 0.64 (0.55-0.74); p trend <0.001. The beneficial associations were observed regardless of participants' sociodemographics (e.g., race, education, and income) and health conditions (e.g., history of cardiometabolic diseases and depression).

DISCUSSION

Our findings support significant benefits of healthy lifestyles for ADRD prevention among socioeconomically disadvantaged Americans, suggesting that promoting healthy lifestyles and reducing barriers to lifestyle changes are crucial to tackling the growing burden and disparities posed by ADRD.

Designing the next-generation clinical care pathway for Alzheimer's disease

The reconceptualization of Alzheimer's disease (AD) as a clinical and biological construct has facilitated the development of biomarker-guided, pathway-based targeted therapies, many of which have reached late-stage development with the near-term potential to enter global clinical practice. These medical advances mark an unprecedented paradigm shift and requires an optimized global framework for clinical care pathways for AD. In this Perspective, we describe the blueprint for transitioning from the current, clinical symptom-focused and inherently late-stage diagnosis and management of AD to the next-generation pathway that incorporates biomarker-guided and digitally facilitated decision-making algorithms for risk stratification, early detection, timely diagnosis, and preventative or therapeutic interventions. We address critical and high-priority challenges, propose evidence-based strategic solutions, and emphasize that the perspectives of affected individuals and care partners need to be considered and integrated.

Black and White individuals differ in dementia prevalence, risk factors, and symptomatic presentation

INTRODUCTION

Although dementia prevalence differs by race, it remains unclear whether cognition and neuropsychiatric symptom severity differ between Black and White individuals with dementia.

METHODS

Using National Alzheimer's Coordinating Center (NACC) data, we evaluated dementia prevalence in non-Hispanic Black and White participants and compared their clinicodemographic characteristics. We examined race differences in cognition, neuropsychiatric symptoms, and functional abilities in participants with dementia using multivariable linear and logistic regression models.

RESULTS

We included 5,700 Black and 31,225 White participants across 39 Alzheimer's Disease Research Centers. Of these, 1,528 (27%) Black and 11,267 (36%) White participants had dementia diagnoses. Despite having lower dementia prevalence, risk factors were more prevalent among Black participants. Black participants with dementia showed greater cognitive deficits, neuropsychiatric symptoms/severity, and functional dependence.

DISCUSSION

Despite lower dementia prevalence, Black participants with dementia had more dementia risk factors, as well as greater cognitive impairment and neuropsychiatric symptom severity than White participants.

Increasing engagement of Hispanics/Latinos in clinical trials on Alzheimer's disease and related dementias

Introduction

Despite evidence that Hispanic/Latino populations are 1.5 times more likely than non-Latino Whites to develop Alzheimer's disease and related dementias (ADRD), Latinos are underrepresented in clinical trials testing treatments for ADRD. Data are needed on facilitators of ADRD clinical trial participation in Latinos. We leveraged in-depth qualitative methods to elucidate barriers and facilitators to participating in ADRD clinical trials in a large and diverse sample of Latinos; and to provide timely and actionable strategies to accelerate representation of Latinos in clinical trials on ADRD.

Methods

Data were collected in California between January 2019 and June 2020 from 25 focus groups (FGs): eight with Latino adults ages 18 to 49 (n = 54), nine with Latino adults ages 50+ (n = 75), and eight with caregivers of Latino older adults with ADRD (n = 52). Twelve community-based organization administrators were also interviewed. Transcripts of FGs and interviews were entered into Atlas.ti software. Three independent team members analyzed the transcripts with inductive/deductive qualitative content analysis. We triangulated data from stakeholder groups across sites, we used collaborative coding, and used the Consolidated Criteria for Reporting Qualitative Research.

Results

An overarching theme was a tension between wanting to learn more about ADRD and to participate in ADRD research but having limited awareness and opportunity. Five themes were identified: (1) remaining in limbo, (2) wanting information about ADRD, (3) wanting information on research about ADRD, (4) clearing researchers through trusted local organizations, and (5) practicing altruism through engagement in research opportunities.

Discussion

To increase representation of Latino communities in clinical trials on ADRD, bilingual information and education on ADRD and clinical trials needs to be better disseminated. Also, working with trusted local, regional, and national organizations can increase participation. Importantly, Latino participation can increase when research teams demonstrate altruistic actions and inform participants of public health reasons requiring their involvement.

HIGHLIGHTS

Participation in clinical trials on Alzheimer's disease and related dementias (ADRD) is limited among Latinos/Hispanics.Knowing the high prevalence of ADRD in Latinos increases willingness to participate.Observing altruism from researchers increases willingness to participate.Invitations from multiple organizations increases willingness to participate.Researchers should include public health reasons requiring Latinos' involvement.

Examine Race/Ethnicity Disparities in Perception, Intention, and Screening of Dementia in a Community Setting: Scoping Review

Background: Delayed detection and diagnosis of Alzheimer’s Disease and related dementia (ADRD) can lead to suboptimal care and socioeconomic burdens on individuals, families, and communities. Our objective is to investigate dementia screening behavior focusing on minority older populations and assess whether there are ethnic differences in ADRD screening behavior. Methods: The scoping review method was utilized to examine ADRD screening behavior and contributing factors for missed and delayed screening/diagnosis focusing on race/ethnicity. Results: 2288 papers were identified, of which 21 met the inclusion criteria. We identified six dimensions of ADRD screening behavior: Noticing Symptoms, Recognizing a problem, Accepting Screen, Intending Screen, Action, and Integrating with time. Final findings were organized into study race/ethnicity, theoretical background, the methods of quantitative and qualitative studies, description and measures of ADRD screening behavior, and racial/ethnic differences in ADRD screening behavior. Conclusions: A trend in ethnic disparities in screening for ADRD was observed. Our findings point to the fact that there is a scarcity of studies focusing on describing ethnic-specific ADRD screening behavior as well as a lack of those examining the impact of ethnicity on ADRD screening behavior, especially studies where Asian Americans are almost invisible.

Psychological and social support associations with mortality and cardiovascular disease in middle-aged American Indians: the Strong Heart Study

PURPOSE

Our study examined psychosocial risk and protective features affecting cardiovascular and mortality disparities in American Indians, including stress, anger, cynicism, trauma, depression, quality of life, and social support.

METHODS

The Strong Heart Family Study cohort recruited American Indian adults from 12 communities over 3 regions in 2001-2003 (N = 2786). Psychosocial measures included Cohen Perceived Stress, Spielberger Anger Expression, Cook-Medley cynicism subscale, symptoms of post-traumatic stress disorder, Centers for Epidemiologic Studies Depression scale, Short Form 12-a quality of life scale, and the Social Support and Social Undermining scale. Cardiovascular events and all-cause mortality were evaluated by surveillance and physician adjudication through 2017.

RESULTS

Participants were middle-aged, 40% male, with mean 12 years formal education. Depression symptoms were correlated with anger, cynicism, poor quality of life, isolation, criticism; better social support was correlated with lower cynicism, anger, and trauma. Adjusted time-to-event regressions found that depression, (poor) quality of life, and social isolation scores formed higher risk for mortality and cardiovascular events, and social support was associated with lower risk. Social support partially explained risk associations in causal mediation analyses.

CONCLUSION

Altogether, our findings suggest that social support is associated with better mood and quality of life; and lower cynicism, stress, and disease risk-even when said risk may be increased by comorbidities. Future research should examine whether enhancing social support can prospectively reduce risk, as an efficient, cost-effective intervention opportunity that may be enacted at the community level.

Validation of Claims Algorithms to Identify Alzheimer's Disease and Related Dementias

BACKGROUND

Using billing data generated through health care delivery to identify individuals with dementia has become important in research. To inform tradeoffs between approaches, we tested the validity of different Medicare claims-based algorithms.

METHODS

We included 5 784 Medicare-enrolled, Health and Retirement Study participants aged older than 65 years in 2012 clinically assessed for cognitive status over multiple waves and determined performance characteristics of different claims-based algorithms.

RESULTS

Positive predictive value (PPV) of claims ranged from 53.8% to 70.3% and was highest using a revised algorithm and 1 year of observation. The tradeoff of greater PPV was lower sensitivity; sensitivity could be maximized using 3 years of observation. All algorithms had low sensitivity (31.3%-56.8%) and high specificity (92.3%-98.0%). Algorithm test performance varied by participant characteristics, including age and race.

CONCLUSION

Revised algorithms for dementia diagnosis using Medicare administrative data have reasonable accuracy for research purposes, but investigators should be cognizant of the tradeoffs in accuracy among the approaches they consider.

Establishing a Framework for Gathering Structural and Social Determinants of Health in Alzheimer's Disease Research Centers

Structural and social determinants of health (SSDoH) are environmental conditions in which individuals are born, live, learn, work, play, worship, and age that affect health, functioning, and quality-of-life outcomes across the life course. Growing evidence suggests that SSDoH can help to explain heterogeneity in outcomes in Alzheimer's disease and Alzheimer's disease and related dementias (AD/ADRD) research and clinical practice. The National Institute on Aging has prioritized collecting SSDoH data to elucidate disease mechanisms and aid discovery of disease-modifying treatments. However, a major nexus of AD/ADRD research, the national network of Alzheimer's Disease Research Centers (ADRCs), collects few SSDoH data. We describe a framework for feasibly gathering and modeling SSDoH data across ADRCs. We lay out key constructs, their measures, and empirical evidence for their importance in elucidating disease and prevention mechanisms. Toward a goal of translation, the framework proposes a modular structure with a core set of measures and options for adjunctive modules. We describe considerations for measuring SSDoH in existing geographically and culturally diverse research cohorts. We also outline a rationale for universal implementation of a set of SSDoH measures and juxtapose the approach with alternatives aimed at collecting SSDoH data.

Promoting Caregiver Mastery in Black American Dementia Caregivers

Over 6 million older Americans live with Alzheimer's disease and related dementias; Black American older adults' prevalence is more than twice that of non-Hispanic White older adults. The Black American dementia caregiving experience can be encapsulated within the Black Family Socioecological Context Model, which provides a conceptual basis for examining social determinants of health at individual, family, community, and societal levels with careful consideration for how the intersection of race, gender, and class of Black American dementia caregivers influences the multiple dimensions of their caregiving experiences. Family dynamics, community setting, and health care systems have a potentially bidirectional influence on these caregivers, which is shaped by historical and ongoing systemic and institutional racism and general disenfranchisement. This Forum article outlines how the Social Cognitive Theory offers ways for Black American dementia caregivers to achieve a sense of mastery within the complicated and fraught ecology within which their caregiving occurs. We propose a research agenda to create programs and interventions for enhancing a sense of mastery among Black American dementia caregivers. Two concepts in particular, "constraints" and "efficacy expectations," provide ways to create a systematic approach to developing successful coping strategies for the constraints perceived by individuals as they undertake and function in the caregiving role. The recognition of the complexity of the caregiving ecosystem and intersectionality of caregivers' experience and identity emphasize the importance of individualization: Each caregiver's experience of this ecosystem-and therefore each Black American dementia caregiver's way to mastery within it-will be uniquely shaped and experienced.

The Living Alone with Cognitive Impairment Project's Policy Advisory Group on Long-Term Services and Supports: Setting a Research Equity Agenda

(1) Background: A United States national policy advisory group (PAG) was convened to identify barriers and facilitators to expand formal long-term services and support (LTSS) for people living alone with cognitive impairment (PLACI), with a focus on equitable access among diverse older adults. The PAG's insights will inform the research activities of the Living Alone with Cognitive Impairment Project, which is aimed at ensuring the equitable treatment of PLACI. (2) Methods: The PAG identified barriers and facilitators of providing effective and culturally relevant LTSS to PLACI via one-on-one meetings with researchers, followed by professionally facilitated discussions among themselves. (3) Results: The PAG identified three factors that were relevant to providing effective and culturally relevant LTSS to PLACI: (i) better characterization of PLACI, (ii) leveraging the diagnosis of cognitive impairment, and (iii) expanding and enhancing services. For each factor, the PAG identified barriers and facilitators, as well as directions for future research. (4) Conclusions: The barriers and facilitators the PAG identified inform an equity research agenda that will help inform policy change.

Risk Factors Associated With Alzheimer Disease and Related Dementias by Sex and Race and Ethnicity in the US

Importance

Previous estimates suggested that 1 in 3 cases of Alzheimer disease and related dementia (ADRDs) in the US are associated with modifiable risk factors, the most prominent being physical inactivity, depression, and smoking. However, these estimates do not account for changes in risk factor prevalence over the past decade and do not consider potential differences by sex or race and ethnicity.

Objective

To update estimates of the proportion of ADRDs in the US that are associated with modifiable risk factors and to assess for differences by sex and race and ethnicity.

Design, Setting, and Participants

For this cross-sectional study, risk factor prevalence and communality were obtained from the nationally representative US Behavioral Risk Factor Surveillance Survey data from January 2018 to December 2018, and relative risks for each risk factor were extracted from meta-analyses. Data were analyzed from December 2020 to August 2021. Respondents included 378 615 noninstitutionalized adults older than 18 years. The number before exclusion was 402 410. Approximately 23 795 (~6%) had missing values on at least 1 of the variables of interest.

Exposures

Physical inactivity, current smoking, depression, low education, diabetes, midlife obesity, midlife hypertension, and hearing loss.

Main Outcomes and Measures

Individual and combined population-attributable risks (PARs) associated with ADRDs, accounting for nonindependence between risk factors.

Results

Among 378 615 individuals, 171 161 (weighted 48.7%) were male, and 134 693 (weighted 21.1%) were 65 years and older. Race and ethnicity data were self-reported and defined by the US Behavioral Risk Factor Surveillance System Data; 6671 participants (weighted 0.9%) were American Indian and Alaska Native, 8043 (weighted 5.1%) were Asian, 29 956 (weighted 11.7%) were Black, 28 042 (weighted 16.0%) were Hispanic (any race), and 294 394 (weighted 64.3%) were White. Approximately 1 in 3 of ADRD cases (36.9%) in the US were associated with 8 modifiable risk factors, the most prominent of which were midlife obesity (17.7%; 95% CI, 17.5-18.0), physical inactivity (11.8%; 95% CI, 11.7-11.9), and low educational attainment (11.7%; 95% CI, 11.5-12.0). Combined PARs were higher in men (35.9%) than women (30.1%) and differed by race and ethnicity: American Indian and Alaska Native individuals, 39%; Asian individuals, 16%; Black individuals, 40%; Hispanic individuals (any race), 34%; and White individuals, 29%. The most prominent modifiable risk factors regardless of sex were midlife obesity for American Indian and Alaska Native individuals, Black individuals, and White individuals; low education for Hispanic individuals; and physical inactivity for Asian individuals.

Conclusions and Relevance

The findings suggest that risk factors associated with ADRDs have changed over the past decade and differ based on sex and race and ethnicity. Alzheimer risk reduction strategies may be more effective if they target higher-risk groups and consider current risk factor profiles.

Association of Race and Ethnicity With Incidence of Dementia Among Older Adults

IMPORTANCE

The racial and ethnic diversity of the US, including among patients receiving their care at the Veterans Health Administration (VHA), is increasing. Dementia is a significant public health challenge and may have greater incidence among older adults from underrepresented racial and ethnic minority groups.

OBJECTIVE

To determine dementia incidence across 5 racial and ethnic groups and by US geographical region within a large, diverse, national cohort of older veterans who received care in the largest integrated health care system in the US.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study within the VHA of a random sample (5% sample selected for each fiscal year) of 1 869 090 participants aged 55 years or older evaluated from October 1, 1999, to September 30, 2019 (the date of final follow-up).

EXPOSURES

Self-reported racial and ethnic data were obtained from the National Patient Care Database. US region was determined using Centers for Disease Control and Prevention (CDC) regions from residential zip codes.

MAIN OUTCOMES AND MEASURES

Incident diagnosis of dementia (9th and 10th editions of the International Classification of Diseases). Fine-Gray proportional hazards models were used to examine time to diagnosis, with age as the time scale and accounting for competing risk of death.

RESULTS

Among the 1 869 090 study participants (mean age, 69.4 [SD, 7.9] years; 42 870 women [2%]; 6865 American Indian or Alaska Native [0.4%], 9391 Asian [0.5%], 176 795 Black [9.5%], 20 663 Hispanic [1.0%], and 1 655 376 White [88.6%]), 13% received a diagnosis of dementia over a mean follow-up of 10.1 years. Age-adjusted incidence of dementia per 1000 person-years was 14.2 (95% CI, 13.3-15.1) for American Indian or Alaska Native participants, 12.4 (95% CI, 11.7-13.1) for Asian participants, 19.4 (95% CI, 19.2-19.6) for Black participants, 20.7 (95% CI, 20.1-21.3) for Hispanic participants, and 11.5 (95% CI, 11.4-11.6) for White participants. Compared with White participants, the fully adjusted hazard ratios were 1.05 (95% CI, 0.98-1.13) for American Indian or Alaska Native participants, 1.20 (95% CI, 1.13-1.28) for Asian participants, 1.54 (95% CI, 1.51-1.57) for Black participants, and 1.92 (95% CI, 1.82-2.02) for Hispanic participants. Across most US regions, age-adjusted dementia incidence rates were highest for Black and Hispanic participants, with rates similar among American Indian or Alaska Native, Asian, and White participants.

CONCLUSIONS AND RELEVANCE

Among older adults who received care at VHA medical centers, there were significant differences in dementia incidence based on race and ethnicity. Further research is needed to understand the mechanisms responsible for these differences.