Association of neighborhood socioeconomic disadvantage and cognitive impairment

Patterns of Factors in the National Institute on Aging Health Disparities Research Framework Domains and Mild Cognitive Impairment Risk

Introduction

Alzheimer's disease and related dementias are public health and social care challenges. This study used the National Institute on Aging Health Disparities Research Framework to organize potential cognitive impairment risk factors. It aimed to examine patterns of environmental, sociocultural, behavioral, and biological factors and identify key components that predict mild cognitive impairment risk.

Methods

This study comprised 2,812 participants from the Mayo Clinic Study of Aging who were cognitively unimpaired at baseline (aged ≥50 years, mean age [SD]=68.9 [9.7] years, 50.4% female). Analyses utilized a 2-stage approach using factor and principal component analyses to group factors from multiple National Institute on Aging Health Disparities Research Framework domains and identify components that predict cognitive impairment risk. Using a cohort study design, the resulting composite scores were considered as covariates for incident mild cognitive impairment analysis using Cox proportional hazards models.

Results

Three principal components explained 40.30% of the variance and were differentially associated with mild cognitive impairment risk. One component (Principal Component 2), which included factors from all 4 domains of the National Institute on Aging Health Disparities Research Framework (including social, group, and playing game activities [sociocultural domain]; exercise and physical activity [behavioral domain]; education/occupation [environmental domain]; and absence of cardiometabolic risk factors/health self-rating [biological domain]), was associated with lower mild cognitive impairment risk (hazard ratio=0.80, 95% CI=0.73, 0.89). The other 2 principal components, also including factors from multiple framework domains, were associated with increased mild cognitive impairment risk.

Conclusions

Derived principal components included factors from multiple framework domains, supporting the multietiology pathways leading to cognitive impairment. These principal components were differentially associated with mild cognitive impairment risk. Identifying key factors from multiple National Institute on Aging Health Disparities Research Framework domains associated with cognitive impairment risk has implications for effectively targeting interventions at multiple levels (e.g., medical, societal, policy) to avert or delay cognitive impairment risk.

Incidence and prevalence of dementia among US Medicare beneficiaries, 2015-21: population based study

OBJECTIVE

To determine the incidence and prevalence of dementia in a nationally representative cohort of US Medicare beneficiaries, stratified by important subgroups.

DESIGN

Population based study.

SETTING

Nationwide study between 2015 and 2021.

PARTICIPANTS

Fee-for-service Medicare beneficiaries aged 66 or older with at least one year of continuous enrollment.

MAIN OUTCOME MEASURES

Incidence and prevalence of dementia, calculated as percentage per person years or percentage of beneficiaries respectively. These metrics were also calculated in key subgroups defined by age, sex, race/ethnicity, and neighborhood socioeconomic status.

RESULTS

A total of 5 025 039 incident cases of dementia were documented from 2015 to 2021. The overall age and sex standardized incidence decreased between 2015 and 2021 from 3.5% to 2.8%. Prevalence increased during this time from 10.5% to 11.8%. Male beneficiaries had a higher age standardized incidence than did female beneficiaries in 2015 (3.5% v 3.4%), a difference that widened by 2021 (2.9% v 2.6%; estimated difference-in-difference 0.94, 95% confidence interval (CI) 0.94 to 0.95; P<0.001). Incidence was highest in 2015 for black beneficiaries (4.2%), followed by Hispanic beneficiaries (3.7%) and white beneficiaries (3.4%), and in 2021 for black beneficiaries (3.1%) followed by white beneficiaries (2.8%) and Hispanic beneficiaries (2.6%); the difference between white and black beneficiaries narrowed from 2015 to 2021 (difference-in-difference 0.92, 95% CI 0.91 to 0.93; P<0.001) as did the difference between white and Hispanic beneficiaries (difference-in-difference 0.88, 0.87 to 0.89; P<0.001).

CONCLUSIONS

The incidence of dementia decreased from 2015 to 2021, but the prevalence increased. Disparities in these measures by race/ethnicity, sex, and neighborhood socioeconomic status should motivate future measures to promote health equity.

The Impact of Health Policy on Total Ankle Arthroplasty Prices in the United States

BACKGROUND

Total ankle arthroplasty (TAA) is increasingly used due to advancements in surgical technology leading to promising results. Although TAA may have a higher upfront complication rate, its long-term benefits, including lower rates of adjacent joint arthritis and subsequent surgeries, may enhance its cost-effectiveness relative to ankle arthrodesis. Notable regional variability in TAA prices exists, influenced in part by state-level political dynamics and healthcare regulations. This study investigates how state-level political affiliation, certificate of need (CON) laws, and Medicaid expansion affect TAA pricing across the United States, with a specific focus on North Carolina.

METHODS

Data were sourced from the Turquoise Health Database, covering TAA prices since 2021. The unit of analysis was at the hospital level, with price defined as the negotiated hospital facility fee for TAA procedures (current procedural terminology code 27702), exclusive of physician fees. Multivariable regression analyses assessed relationships between TAA prices and factors, including CON regulations, Medicaid expansion, political affiliation, and socioeconomic variables like the area deprivation index. Political affiliation was assessed using both a composite score integrating five indicators of state political control and the Cook Partisan Voting Index for a more granular approach.

RESULTS

States with CON regulations showed lower TAA prices, with average savings of $1,650. Medicaid expansion correlated with higher prices, with an average increase of $1,690. The composite political score showed minimal effect, although the Cook Partisan Voting Index indicated higher prices in Republican-leaning states. In North Carolina, higher area deprivation index scores correlated with reduced TAA prices by $15,331.50, potentially due to competitive market pressures or reliance on government payers.

CONCLUSION

CON laws may reduce costs, whereas Medicaid expansion correlates with higher prices. Political affiliation shows minimal influence, with Republican affiliation weakly associated with higher prices. These findings provide insights for policymakers aiming to balance cost control and access to TAA.

LEVEL OF EVIDENCE

Level IV.

Neighborhood disadvantage and the incidence of dementia in US Black women

INTRODUCTION

We investigated the association of neighborhood disadvantage with the incidence of Alzheimer's disease and related dementias (ADRD) in the longitudinal Black Women's Health Study (BWHS).

METHODS

The study included 10,915 BWHS participants enrolled in Medicare for at least 1 year from 2012 to 2020. The Area Deprivation Index (ADI) was assigned to participant residential block groups over follow-up. ADRD cases were identified from Medicare files.

RESULTS

Age- and education-adjusted hazard ratios (HRs) for ADRD increased as neighborhood disadvantage increased, to 1.42 (95% confidence interval [CI] 1.06-1.91) in the most disadvantaged quintile compared to the least disadvantaged quintile, with a significant linear trend (p = 0.012). Associations remained, although somewhat attenuated, when individual income was controlled.

DISCUSSION

The present study adds to the evidence showing an association between living in a disadvantaged neighborhood and poorer brain health. The area-level association of deprivation with ADRD was in part explained by individual differences in socioeconomic status (SES).

HIGHLIGHTS

The study assessed neighborhood deprivation in the largest cohort of US Black women. Cases of dementia were ascertained from Medicare claims files over 9 years of follow-up. Higher levels of area deprivation were associated with higher dementia risk.

Exposure to neighborhood concentrated poverty is associated with faster decline in episodic memory among midlife women

INTRODUCTION

Neighborhood-level socioeconomic status (nSES) is associated with risk for cognitive impairment, but prior studies assessed nSES within an individual's own residential area without considering the distribution of nSES among adjacent areas.

METHODS

Using up to 14 years of data from the Study of Women's Health Across the Nation (N = 1391, mean age = 54), we examined whether geographic clustering of concentrated neighborhood poverty was associated with cognitive decline over midlife.

RESULTS

Greater neighborhood concentrated poverty was associated with faster decline in episodic memory but not in processing speed or working memory. Living in high concentrated poverty areas was linked to a 7% episodic memory decline per decade (both immediate and delayed recall), with Black women experiencing the steepest decline at 10% per decade (delayed recall).

DISCUSSION

Women living in concentrated poverty areas exhibited accelerated decline in episodic memory during midlife. Neighborhood concentrated poverty may impact risk for future cognitive impairment and ADRD.

HIGHLIGHTS

Living in concentrated poverty areas predicted a more rapid episodic memory decline. This pattern was most pronounced among Black women. The cohort was a racially/ethnically diverse cohort of midlife women across the US. Neighborhood concentrated poverty may contribute to the risk of ADRD.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Neighborhood-level socioeconomic disadvantage is associated with multiple cognitive domains in a community sample of older adults

Greater neighborhood disadvantage is associated with poorer global cognition. However, less is known about the variation in the magnitude of neighborhood effects across individual cognitive domains and whether the strength of these associations differs by individual-level factors. The current study investigated these questions in a community sample of older adults (N = 166, mean age = 72.5 years, 51% women), who reported current addresses, linked to state-level Area Deprivation Index rankings, and completed remote and validated neuropsychological tests of verbal intelligence (North American Adult Reading Test), verbal fluency (Controlled Oral Word Association Test), attention (Digit Span Forward), and working memory (Digit Span Backward and Sequencing, Letter-Number Sequencing). Linear regressions tested associations between neighborhood disadvantage and each cognitive test, controlling for individual-level factors (age, sex, education). Exploratory analyses tested moderation by each individual-level factor. Independent of individual-level factors, greater neighborhood disadvantage was associated with lower cognitive performance across domains: verbal intelligence (β = 0.30, p < .001), verbal fluency (β = -0.19, p = .014), attention (β = -0.19, p = .024), and two of three tests of working memory (β = -0.17- -0.22, ps = .004-.039). Results were robust to correction for multiple comparisons and tests of spatial autocorrelation. In addition, higher neighborhood disadvantage was associated with lower verbal fluency for older - but not younger-older adults (p = .035) and with poorer working memory in women but not men (p < .001). Education did not moderate associations. Findings suggest that older adults living in more disadvantaged neighborhoods exhibit lower cognitive performance, particularly in the domain of verbal intelligence. Continued investigation of effect modification may be fruitful for uncovering for whom associations are strongest.

Alzheimer's Disease Dementia Prevalence in the United States: A County-Level Spatial Machine Learning Analysis

A growing body of literature has examined the impact of neighborhood characteristics on Alzheimer's disease (AD) dementia, yet the spatial variability and relative importance of the most influential factors remain underexplored. We compiled various widely recognized factors to examine spatial heterogeneity and associations with AD dementia prevalence via geographically weighted random forest (GWRF) approach. The GWRF outperformed conventional models with an out-of-bag R2 of 74.8% in predicting AD dementia prevalence and the lowest error (MAE = 0.34, RMSE = 0.45). Key findings showed that mobile homes were the most influential factor in 19.9% of U.S. counties, followed by NDVI (17.4%), physical inactivity (12.9%), households with no vehicle (11.3%), and particulate matter (10.4%), while other primary factors affecting <10% of U.S. counties. Findings highlight the need for county-specific interventions tailored to local risk factors. Policies should prioritize increasing affordable housing stability, expanding green spaces, improving transportation access, promoting physical activity, and reducing air pollution exposure.

Association Between Greater Social Vulnerability and Delayed Glaucoma Surgery

PURPOSE

Timing of surgical intervention in glaucoma is crucial to preserving sight. While ocular characteristics that increase surgical risk are known, the impact of neighborhood-level social risk factors such as the Social Vulnerability Index (SVI) and Area Deprivation Index (ADI) on time to glaucoma surgery is unknown. The objective of this study was to evaluate the association between SVI or ADI scores and the timing of glaucoma surgical intervention.

DESIGN

Retrospective cohort study.

METHODS

Adult subjects with open-angle glaucoma were identified from the Bascom Palmer Glaucoma Repository using International Classification of Disease-10 codes. Subject demographics, ocular characteristics, and standard automated perimetry data were extracted. Geocoded data were obtained using subject residences and American Community Survey data. Univariable and multivariable time-to-event survival analyses using accelerated failure time models were completed to evaluate whether geocoded SVI and ADI scores accelerated or delayed time to glaucoma surgery from initial glaucoma diagnosis in the electronic health record.

RESULTS

A total of 10,553 eyes from 6934 subjects were evaluated, of which 637 eyes (6.0%) from 568 subjects (8.2%) underwent glaucoma surgery. Mean age was 68.3 ± 13.5 years, with 57.9% female, 21.5% Black, and 34.5% Hispanic subjects. Mean follow-up time was 5.0 ± 2.1 years, with time to surgery of 3.2 ± 1.9 years. Multivariable accelerated failure time models demonstrated that higher mean intraocular pressure (time ratio [TR] 0.27 per 5 mm Hg higher; 95% confidence interval [CI]: 0.23-0.31, P < .001), faster standard automated perimetry rate of progression (TR 0.74 per 0.5 dB/year faster; 95% CI: 0.69-0.78, P < .001), moderate (TR 0.69; 95% CI: 0.56-0.85, P < .001) or severe baseline severity (TR 0.39; 95% CI: 0.32-0.47, P < .001), and thinner central corneal thickness (TR 0.85 per 50 µm thinner; 95% CI: 0.77-0.95, P = .003) all accelerated time to surgery. In contrast, overall SVI delayed surgery (TR 1.11 per 25% increase; 95% CI: 1.03-1.20, P = .006). Specifically, SVI Themes 1 (TR 1.08; 95% CI: 1.01-1.17, P = .037) and 4 (TR 1.11; 95% CI: 1.03-1.19, P = .006) were significant. Patients from the most deprived neighborhoods (highest national ADI quartile) had a 68% increase in time to surgery compared to the least deprived quartile (TR 1.68; 95% CI: 1.20-2.36, P = .002).

CONCLUSIONS

Residence in areas with higher SVI or ADI scores was associated with delayed glaucoma surgery after controlling for demographic and ocular parameters. Awareness of such disparities can guide initiatives aimed at achieving parity in health outcomes.

Higher socioeconomic deprivation in areas predicts cognitive decline in New Zealanders without cognitive impairment

Previous studies identified individual-level socioeconomic factors as key determinants of cognitive health. This study investigated the effect of area-based socioeconomic deprivation on cognitive outcomes in midlife to early late-life New Zealanders without cognitive impairment at baseline. Data stemmed from a subsample of the New Zealand Health, Work and Retirement Study, a cohort study on ageing, who completed face-to-face interviews and were reassessed two years later. Cognitive functioning was measured using Addenbrooke's Cognitive Examination-Revised, adapted for culturally acceptable use in Aotearoa New Zealand. Area-based socioeconomic deprivation was assessed using the New Zealand Deprivation Index (NZDep2006). Linear mixed-effects models analysed the association between area-based socioeconomic deprivation and cognitive outcomes. The analysis included 783 participants without cognitive impairment at baseline (54.7% female, mean age 62.7 years, 25.0% Māori, the Indigenous people of Aotearoa New Zealand). There was an association between higher area-based socioeconomic deprivation and lower cognitive functioning (B = -0.08, 95%CI: -0.15;-0.01; p = .050) and cognitive decline (B = -0.12, 95%CI: -0.20;-0.04, p = .013) over two years, while controlling for covariates. The findings emphasise the importance of considering neighbourhood characteristics and broader socioeconomic factors in strategies aimed at mitigating cognitive health disparities and reducing the impact of dementia in disadvantaged communities.

Individual socioeconomic status, neighborhood disadvantage, and cognitive aging: A longitudinal analysis of the CLSA

BACKGROUND

There are likely many contributors to variation in the rate of cognitive decline in middle and late adulthood, including individual and neighborhood socio-economic factors. This study examines whether individual socio-economic factors, namely income and wealth, correlate with cognitive decline, in part, through neighborhood-level social and material disadvantage.

METHODS

Using the three waves of data collection from the Canadian Longitudinal Study on Aging (CLSA), this study included 51,338 participants between the age of 45 and 85 years at baseline (51% female). Individual socio-economic status (SES) was assessed by annual household income and by the current value of savings and investments. Neighborhood disadvantage was measured by area-based material and social deprivation indices. Cognition was measured at each wave using verbal fluency, mental alternations, and delayed word recall. Latent change score models, incorporating direct and indirect pathways, were constructed to estimate the indirect effect of individual SES on cognitive change through area-level disadvantage. Multi-group models were constructed on the basis of age-group (45-64 years; 65-74 years; or 75+ years) to allow for varying estimates across age.

RESULTS

Among 45-64-year-olds, income and wealth had indirect effects on initial cognitive level and on rate of cognitive decline through material disadvantage (standardized indirect effects = 0.01, p < 0.001), but only wealth had an indirect effect through social disadvantage (p = 0.019). Among 65-74-year-olds, income and wealth had indirect effects on initial cognitive level (p < 0.01) but not on rate of cognitive decline (p > 0.05), and among 75+ year-olds, no indirect effects were observed (p > 0.05). Wealth and income had direct effects, independent of neighborhood disadvantage, on cognition in all age groups (p < 0.05).

CONCLUSIONS

Among middle-aged adults, greater individual SES may mitigate cognitive decline, in part, by allowing individuals to live in more materially and socially advantaged neighborhoods.

Impact of neighborhood disadvantage on cardiometabolic health and cognition in a community-dwelling cohort

INTRODUCTION

Neighborhood disadvantage may be an important determinant of cardiometabolic health and cognitive aging. However, less is known about relationships among individuals with mild cognitive impairment (MCI).

METHODS

The objective of this study is to investigate the relationship between neighborhood disadvantage measured by national Area Deprivation Index (ADI) rank with measures of cardiometabolic health and cognition among Wake Forest (WF) Alzheimer's Disease Research Center (ADRC) participants, with and without MCI.

RESULTS

ADI was positively associated with blood pressure and cardiometabolic index (CMI), and negatively associated with global and Preclinical Alzheimer's Cognitive Composite (PACC5) scores, in cognitively unimpaired (CU) individuals. ADI was only positively associated with hemoglobin A1c (HbA1c) in MCI.

DISCUSSION

Neighborhood disadvantage is associated more strongly with measures of cardiometabolic health and cognition among CU individuals rather than MCI. These findings demonstrate a need for structural solutions to address social determinants of health in an attempt to reduce cardiometabolic and cognitive risks.

Dementia, dementia's risk factors and premorbid brain structure are concentrated in disadvantaged areas: National register and birth-cohort geographic analyses

INTRODUCTION

Dementia risk may be elevated in socioeconomically disadvantaged neighborhoods. Reasons for this remain unclear, and this elevation has yet to be shown at a national population level.

METHODS

We tested whether dementia was more prevalent in disadvantaged neighborhoods across the New Zealand population (N = 1.41 million analytic sample) over a 20-year observation. We then tested whether premorbid dementia risk factors and MRI-measured brain-structure antecedents were more prevalent among midlife residents of disadvantaged neighborhoods in a population-representative NZ-birth-cohort (N = 938 analytic sample).

RESULTS

People residing in disadvantaged neighborhoods were at greater risk of dementia (HR per-quintile-disadvantage-increase = 1.09, 95% confidence interval [CI]:1.08-1.10) and, decades before clinical endpoints typically emerge, evidenced elevated dementia-risk scores (CAIDE, LIBRA, Lancet, ANU-ADRI, DunedinARB; β's 0.31-0.39) and displayed dementia-associated brain structural deficits and cognitive difficulties/decline.

DISCUSSION

Disadvantaged neighborhoods have more residents with dementia, and decades before dementia is diagnosed, residents have more dementia-risk factors and brain-structure antecedents. Whether or not neighborhoods causally influence risk, they may offer scalable opportunities for primary dementia prevention.

Deriving life-course residential histories in brain bank cohorts: A feasibility study

INTRODUCTION

The exposome is theorized to interact with biological mechanisms to influence risk for Alzheimer's disease but is not well-integrated into existing Alzheimer's Disease Research Center (ADRC) brain bank data collection.

METHODS

We apply public data tracing, an iterative, dual abstraction and validation process rooted in rigorous historic archival methods, to develop life-course residential histories for 1254 ADRC decedents.

RESULTS

The median percentage of the life course with an address is 78.1% (IQR 24.9); 56.5% of the sample has an address for at least 75% of their life course. Archivists had 89.7% agreement at the address level. This method matched current residential survey methodology 97.4% on average.

DISCUSSION

This novel method demonstrates feasibility, reproducibility, and rigor for historic data collection. To our knowledge, this is the first study to show that public data tracing methods for brain bank decedent residential history development can be used to better integrate the social exposome with biobank specimens.

HIGHLIGHTS

Public data tracing compares favorably to survey-based residential history. Public data tracing is feasible and reproducible between archivists. Archivists achieved 89.7% agreement at the address level. This method identifies residences for nearly 80% of life-years, on average. This novel method enables brain banks to add social characterizations.

The association between neighborhood deprivation and DNA methylation in an autopsy cohort

Previous research has found that living in a disadvantaged neighborhood is associated with poor health outcomes. Living in disadvantaged neighborhoods may alter inflammation and immune response in the body, which could be reflected in epigenetic mechanisms such as DNA methylation (DNAm). We used robust linear regression models to conduct an epigenome-wide association study examining the association between neighborhood deprivation (Area Deprivation Index; ADI), and DNAm in brain tissue from 159 donors enrolled in the Emory Goizueta Alzheimer's Disease Research Center (Georgia, USA). We found one CpG site (cg26514961, gene PLXNC1) significantly associated with ADI after controlling for covariates and multiple testing (p-value=5.0e-8). Effect modification by APOE ε4 was statistically significant for the top ten CpG sites from the EWAS of ADI, indicating that the observed associations between ADI and DNAm were mainly driven by donors who carried at least one APOE ε4 allele. Four of the top ten CpG sites showed a significant concordance between brain tissue and tissues that are easily accessible in living individuals (blood, buccal cells, saliva), including DNAm in cg26514961 (PLXNC1). Our study identified one CpG site (cg26514961, PLXNC1 gene) that was significantly associated with neighborhood deprivation in brain tissue. PLXNC1 is related to immune response, which may be one biological pathway how neighborhood conditions affect health. The concordance between brain and other tissues for our top CpG sites could make them potential candidates for biomarkers in living individuals.

Neighborhood disadvantage reduces cognitive reserve independent of neuropathologic change

INTRODUCTION

Individuals in socioeconomically disadvantaged neighborhoods exhibit increased risk for impaired cognitive function. Whether this association relates to the major dementia-related neuropathologies is unknown.

METHODS

This cross-sectional study included 469 autopsy cases from 2011 to 2023. The relationships between neighborhood disadvantage measured by Area Deprivation Index (ADI) percentiles categorized into tertiles, cognition evaluated by the last Mini-Mental State Examination (MMSE) scores before death, and 10 dementia-associated proteinopathies and cerebrovascular disease were assessed using regression analyses.

RESULTS

Higher ADI was significantly associated with lower MMSE score. This was mitigated by increasing years of education. ADI was not associated with an increase in dementia-associated neuropathologic change. Moreover, the significant association between ADI and cognition remained even after controlling for changes in major dementia-associated proteinopathies or cerebrovascular disease.

DISCUSSION

Neighborhood disadvantage appears to be associated with decreased cognitive reserve. This association is modified by education but is independent of the major dementia-associated neuropathologies.

Systematic Review of Longitudinal Evidence and Methodologies for Research on Neighborhood Characteristics and Brain Health

Objective: Synthesize longitudinal research evaluating neighborhood environments and cognition to identify methodological approaches, findings, and gaps. Methods: Included studies evaluated associations between neighborhood and cognition longitudinally among adults >45 years (or mean age of 65 years) living in developed nations. We extracted data on sample characteristics, exposures, outcomes, methods, overall findings, and assessment of disparities. Results: Forty studies met our inclusion criteria. Most (65%) measured exposure only once and a majority focused on green space and/or blue space (water), neighborhood socioeconomic status, and recreation/physical activity facilities. Similarly, over half studied incident impairment, cognitive function or decline (70%), with one examining MRI (2.5%) or Alzheimer's disease (7.5%). While most studies used repeated measures analysis to evaluate changes in the brain health outcome (51%), many studies did not account for any type of correlation within neighborhoods (35%). Less than half evaluated effect modification by race/ethnicity, socioeconomic status, and/or sex/gender. Evidence was mixed and dependent on exposure or outcome assessed. Conclusion: Although longitudinal research evaluating neighborhood and cognitive decline has expanded, gaps remain in types of exposures, outcomes, analytic approaches, and sample diversity.

A Framework for Assessing the Effects of Climate Change on Dementia Risk and Burden

Alzheimer's disease and related dementias (ADRD) represent a public health crisis poised to worsen in a changing climate. Substantial dementia burden is modifiable, attributable to risk rooted in social and environmental conditions. Climate change threatens older populations in numerous ways, but implications for cognitive aging are poorly understood. We illuminate key mechanisms by which climate change will shape incidence and lived experiences of ADRD, and propose a framework for strengthening research, clinical, and policy actions around cognitive health in the context of climate change. Direct impacts and indirect risk pathways operating through built, social, interpersonal, and biomedical systems are highlighted. Air pollution compromises brain health directly and via systemic cardiovascular and respiratory ailments. Flooding and extreme temperatures constrain health behaviors like physical activity and sleep. Medical care resulting from climate-related health shocks imposes economic and emotional tolls on people living with dementia and caregivers. Throughout, inequitable distributions of climate-exacerbated risks and adaptive resources compound existing disparities in ADRD incidence, comorbidities, and care burden. Translational research, including work prioritizing underserved communities, is crucial. A mechanistic framework can guide research questions and methods and identify clinical- and policy-level intervention loci for prevention and mitigation of climate-related impacts on ADRD risk and burden.

Race, community disadvantage, and cognitive decline: Findings from KHANDLE and STAR

INTRODUCTION

Community disadvantage is associated with late-life cognition. Few studies examine its contribution to racial disparities in cognition/cognitive change.

METHODS

Inverse probability weighted models estimated expected mean differences in cognition/cognitive change attributed to residing in less advantaged communities, defined as cohort top quintile of Area Deprivation Indices (ADI): childhood 66-100; adulthood ADI 5-99). Interactions by race tested.

RESULTS

More Black participants resided in less advantaged communities. Semantic memory would be lower if all participants had resided in less advantaged childhood (b = -0.16, 95% confidence interval [CI] = -0.30, -0.03) or adulthood (b = -0.14, 95% CI = -0.22, -0.04) communities. Race interactions indicated that, among Black participants, less advantaged childhood communities were associated with higher verbal episodic memory (interaction p-value = 0.007) and less advantaged adulthood communities were associated with lower semantic memory (interaction p-value = 0.002).

DISCUSSION

Examining racial differences in levels of community advantage and late-life cognitive decline is a critical step toward unpacking community effects on cognitive disparities.

Experiences of in-hospital care among dementia caregivers in the context of high neighborhood-level disadvantage

BACKGROUND

Persons living with dementia (PLWD) experience high rates of hospitalization and rehospitalization, exposing them to added risk for adverse outcomes including delirium, hastened cognitive decline, and death. Hospitalizations can also increase family caregiver strain. Despite disparities in care quality surrounding hospitalizations for PLWD, and evidence suggesting that exposure to neighborhood-level disadvantage increases these inequities, experiences with hospitalization among PLWD and family caregivers exposed to greater levels of neighborhood disadvantage are poorly understood. This study examined family caregiver perspectives and experiences of hospitalizations among PLWD in the context of high neighborhood-level disadvantage.

METHODS

We analyzed data from the Stakeholders Understanding of Prevention Protection and Opportunities to Reduce HospiTalizations (SUPPORT) study, an in-depth, multisite qualitative study examining hospitalization and rehospitalization of PLWD in the context of high neighborhood disadvantage, to identify caregiver perspectives and experiences of in-hospital care. Data were analyzed using rapid identification of themes; duplicate transcript review was used to enhance rigor.

RESULTS

Data from N = 54 individuals (47 individual interviews, 2 focus groups with 7 individuals) were analyzed. Sixty-three percent of participants identified as Black/African American, 35% as non-Hispanic White, and 2% declined to report. Caregivers' experiences were largely characterized by PLWD receiving suboptimal care that caregivers viewed as influenced by system pressures and inadequate workforce competencies, leading to communication breakdowns and strain. Caregivers described poor collaboration between clinicians and caregivers with regard to in-hospital care delivery, including transitional care. Caregivers also highlighted the lack of person-focused care and the exclusion of the PLWD from care.

CONCLUSIONS

Caregiver perspectives highlight opportunities for improving hospital care for PLWD in the context of neighborhood disadvantage and recognition of broader issues in care structure that limit their capacity to be actively involved in care. Further work should examine and develop strategies to improve caregiver integration during hospitalizations across diverse contexts.

Association Between Socioeconomic Factors, Race, and Use of a Specialty Memory Clinic

BACKGROUND AND OBJECTIVES

The capacity of specialty memory clinics in the United States is very limited. If lower socioeconomic status or minoritized racial group is associated with reduced use of memory clinics, this could exacerbate health care disparities, especially if more effective treatments of Alzheimer disease become available. We aimed to understand how use of a memory clinic is associated with neighborhood-level measures of socioeconomic factors and the intersectionality of race.

METHODS

We conducted an observational cross-sectional study using electronic health record data to compare the neighborhood advantage of patients seen at the Washington University Memory Diagnostic Center with the catchment area using a geographical information system. Furthermore, we compared the severity of dementia at the initial visit between patients who self-identified as Black or White. We used a multinomial logistic regression model to assess the Clinical Dementia Rating at the initial visit and t tests to compare neighborhood characteristics, including Area Deprivation Index, with those of the catchment area.

RESULTS

A total of 4,824 patients seen at the memory clinic between 2008 and 2018 were included in this study (mean age 72.7 [SD 11.0] years, 2,712 [56%] female, 543 [11%] Black). Most of the memory clinic patients lived in more advantaged neighborhoods within the overall catchment area. The percentage of patients self-identifying as Black (11%) was lower than the average percentage of Black individuals by census tract in the catchment area (16%) (p < 0.001). Black patients lived in less advantaged neighborhoods, and Black patients were more likely than White patients to have moderate or severe dementia at their initial visit (odds ratio 1.59, 95% CI 1.11-2.25).

DISCUSSION

This study demonstrates that patients living in less affluent neighborhoods were less likely to be seen in one large memory clinic. Black patients were under-represented in the clinic, and Black patients had more severe dementia at their initial visit. These findings suggest that patients with a lower socioeconomic status and who identify as Black are less likely to be seen in memory clinics, which are likely to be a major point of access for any new Alzheimer disease treatments that may become available.

Association of neighborhood deprivation with white matter connectome abnormalities in temporal lobe epilepsy

OBJECTIVE

Social determinants of health, including the effects of neighborhood disadvantage, impact epilepsy prevalence, treatment, and outcomes. This study characterized the association between aberrant white matter connectivity in temporal lobe epilepsy (TLE) and disadvantage using a US census-based neighborhood disadvantage metric, the Area Deprivation Index (ADI), derived from measures of income, education, employment, and housing quality.

METHODS

Participants including 74 TLE patients (47 male, mean age = 39.2 years) and 45 healthy controls (27 male, mean age = 31.9 years) from the Epilepsy Connectome Project were classified into ADI-defined low and high disadvantage groups. Graph theoretic metrics were applied to multishell connectome diffusion-weighted imaging (DWI) measurements to derive 162 × 162 structural connectivity matrices (SCMs). The SCMs were harmonized using neuroCombat to account for interscanner differences. Threshold-free network-based statistics were used for analysis, and findings were correlated with ADI quintile metrics. A decrease in cross-sectional area (CSA) indicates reduced white matter integrity.

RESULTS

Sex- and age-adjusted CSA in TLE groups was significantly reduced compared to controls regardless of disadvantage status, revealing discrete aberrant white matter tract connectivity abnormalities in addition to apparent differences in graph measures of connectivity and network-based statistics. When comparing broadly defined disadvantaged TLE groups, differences were at trend level. Sensitivity analyses of ADI quintile extremes revealed significantly lower CSA in the most compared to least disadvantaged TLE group.

SIGNIFICANCE

Our findings demonstrate (1) the general impact of TLE on DWI connectome status is larger than the association with neighborhood disadvantage; however, (2) neighborhood disadvantage, indexed by ADI, revealed modest relationships with white matter structure and integrity on sensitivity analysis in TLE. Further studies are needed to explore this relationship and determine whether the white matter relationship with ADI is driven by social drift or environmental influences on brain development. Understanding the etiology and course of the disadvantage-brain integrity relationship may serve to inform care, management, and policy for patients.

Racial, ethnic and neighborhood socioeconomic differences in incidence of dementia: A regional retrospective cohort study

BACKGROUND

Evidence on the effects of neighborhood socioeconomic disadvantage on dementia risk in racially and ethically diverse populations is limited. Our objective was to evaluate the relative extent to which neighborhood disadvantage accounts for racial/ethnic variation in dementia incidence rates. Secondarily, we evaluated the spatial relationship between neighborhood disadvantage and dementia risk.

METHODS

In this retrospective study using electronic health records (EHR) at two regional health systems in Northeast Ohio, participants included 253,421 patients aged >60 years who had an outpatient primary care visit between January 1, 2005 and December 31, 2015. The date of the first qualifying visit served as the study baseline. Cumulative incidence of composite dementia outcome, defined as EHR-documented dementia diagnosis or dementia-related death, stratified by neighborhood socioeconomic deprivation (as measured by Area Deprivation Index) was determined by competing-risk regression analysis, with non-dementia-related death as the competing risk. Fine-Gray sub-distribution hazard ratios were determined for neighborhood socioeconomic deprivation, race/ethnicity, and clinical risk factors. The degree to which neighborhood socioeconomic position accounted for racial/ethnic disparities in the incidence of composite dementia outcome was evaluated via mediation analysis with Poisson rate models.

RESULTS

Increasing neighborhood disadvantage was associated with increased risk of EHR-documented dementia diagnosis or dementia-related death (most vs. least disadvantaged ADI quintile HR = 1.76, 95% confidence interval = 1.69-1.84) after adjusting for age and sex. The effect of neighborhood disadvantage on this composite dementia outcome remained after accounting for known medical risk factors of dementia. Mediation analysis indicated that neighborhood disadvantage accounted for 34% and 29% of the elevated risk for composite dementia outcome in Hispanic and Black patients compared to White patients, respectively.

CONCLUSION

Neighborhood disadvantage is related to the risk of EHR-documented dementia diagnosis or dementia-related death and accounts for a portion of racial/ethnic differences in dementia burden, even after adjustment for clinically important confounders.

Association of Neighborhood Deprivation With Cognitive and Mood Outcomes in Adults With Pharmacoresistant Temporal Lobe Epilepsy

BACKGROUND AND OBJECTIVES

Temporal lobe epilepsy (TLE) is the most common adult form of epilepsy and is associated with a high risk of cognitive deficits and depressed mood. However, little is known about the role of environmental factors on cognition and mood in TLE. This cross-sectional study examined the relationship between neighborhood deprivation and neuropsychological function in adults with TLE.

METHODS

Neuropsychological data were obtained from a clinical registry of patients with TLE and included measures of intelligence, attention, processing speed, language, executive function, visuospatial skills, verbal/visual memory, depression, and anxiety. Home addresses were used to calculate the Area Deprivation Index (ADI) for each individual, which were separated into quintiles (i.e., quintile 1 = least disadvantaged and quintile 5 = most disadvantaged). Kruskal-Wallis tests compared quintile groups on cognitive domain scores and mood and anxiety scores. Multivariable regression models, with and without ADI, were estimated for overall cognitive phenotype and for mood and anxiety scores.

RESULTS

A total of 800 patients (median age 38 years; 58% female) met all inclusion criteria. Effects of disadvantage (increasing ADI) were observed across nearly all measured cognitive domains and with significant increases in symptoms of depression and anxiety. Furthermore, patients in more disadvantaged ADI quintiles had increased odds of a worse cognitive phenotype (p = 0.013). Patients who self-identified as members of minoritized groups were overrepresented in the most disadvantaged ADI quintiles and were 2.91 (95% CI 1.87-4.54) times more likely to be in a severe cognitive phenotype than non-Hispanic White individuals (p < 0.001). However, accounting for ADI attenuated this relationship, suggesting neighborhood deprivation may account for some of the relationship between race/ethnicity and cognitive phenotype (ADI-adjusted proportional odds ratio 1.82, 95% CI 1.37-2.42).

DISCUSSION

These findings highlight the importance of environmental factors and regional characteristics in neuropsychological studies of epilepsy. There are many potential mechanisms by which neighborhood disadvantage can adversely affect cognition (e.g., fewer educational opportunities, limited access to health care, food insecurity/poor nutrition, and greater medical comorbidities). Future research will seek to investigate these potential mechanisms and determine whether structural and functional alterations in the brain moderate the relationship between ADI and cognition.