Does Neighborhood Socioeconomic Status Alter Memory Change Associated with a Cancer Diagnosis? Preliminary Evidence from the US Health and Retirement Study.

BACKGROUND: Neighborhood disadvantage has been linked to cognitive impairment, but little is known about the effect of neighborhood disadvantage on long-term cancer-related memory decline. METHODS: Incident cancer diagnosis and memory (immediate and delayed recall, combined with proxy-reported memory) were assessed at biennial interviews in the US Health and Retirement Study (N = 13,293, 1998-2016). Neighborhood disadvantage was measured using the National Neighborhood Data Archive disadvantage index, categorized into tertiles (T1: least disadvantaged-T3: most disadvantaged). Linear mixed-effects models estimated the standardized memory trajectories in participants with or without cancer, by neighborhood disadvantage. RESULTS: Living in more disadvantaged neighborhoods was associated with worse mean memory function and steeper memory declines, regardless of cancer status. An incident cancer diagnosis was associated with an acute memory drop for those living in least disadvantaged neighborhoods but not more disadvantaged neighborhoods [T1: -0.05, 95% confidence interval (CI): -0.08, -0.01; T3: -0.13, 95% CI: -0.06, 0.03]. Cancer survivors in the least disadvantaged neighborhoods had a slight memory advantage in the years prior to diagnosis (T1: 0.09, 95% CI: 0.04, 0.13) and after diagnosis (T1: 0.07, 95% CI: 0.01, 0.13). CONCLUSIONS: An incident cancer diagnosis among those living in the least disadvantaged neighborhoods was associated with an acute memory drop at the time of diagnosis and a long-term memory advantage before and after diagnosis compared with cancer-free individuals in similar neighborhoods. IMPACT: These findings could inform interventions to promote cancer survivor's long-term aging. Future studies should investigate the social and biological pathways through which neighborhood socioeconomic status could influence cancer-related memory changes.

Development of the Longitudinal Study of Health and Ageing in Kenya (LOSHAK).

In Kenya, the number of adults aged ≥60 is expected to nearly quadruple by 2050, making it one of the most rapidly aging countries in Sub-Saharan Africa (SSA). Accordingly, we designed the Longitudinal Study of Health and Ageing in Kenya (LOSHAK) to generate novel data to address the health and economic consequences of this demographic transition. Specifically, LOSHAK will investigate the social, economic, environmental, biological, and policy processes that shape late-life health and economic well-being in Kenya. Modeled on the U.S. Health and Retirement Study (HRS), LOSHAK joins a network of harmonized studies on aging in >45 countries worldwide; however, LOSHAK will be only the 2nd such study in SSA. The current feasibility and pilot phase of LOSHAK will validate measures and data collection procedures in a purposive sample of Kenyan adults aged ≥45 years. We have linguistically and culturally translated instruments while aiming to maintain harmonization with both existing HRS network studies and the ongoing Kenya Life Panel Survey. The current phase of LOSHAK is nested within the Kaloleni/Rabai Community Health and Demographic Surveillance System on the coast of Kenya. LOSHAK will advance population aging research in low- and middle-income countries through the study of (a) biomarkers and physiological measures; (b) the impacts of air pollution and climate vulnerability; (c) Alzheimer's disease and related dementias, mental health, disability, caregiving, and psychosocial wellbeing; and (d) economic security, including the impact of social welfare. LOSHAK will inform future public health and economic policy to address challenges related to rapid aging in Kenya and throughout SSA. Accordingly, this paper aims to introduce and provide a description of LOSHAK and its aims and objectives, as well as to inform the scientific community of current study activities being used to build toward the full population-representative study.

Identifying Sources of Inter-Hospital Variation in Episode Spending for Sepsis Care.

OBJECTIVE: To evaluate inter-hospital variation in 90-day total episode spending for sepsis, estimate the relative contributions of each component of spending, and identify drivers of spending across the distribution of episode spending on sepsis care. DATA SOURCES/STUDY SETTING: Medicare fee-for-service claims for beneficiaries (n=324,694) discharged from acute care hospitals for sepsis, defined by MS-DRG, between October 2014 and September 2018. RESEARCH DESIGN: Multiple linear regression with hospital-level fixed effects was used to identify average hospital differences in 90-day episode spending. Separate multiple linear regression and quantile regression models were used to evaluate drivers of spending across the episode spending distribution. RESULTS: The mean total episode spending among hospitals in the most expensive quartile was $30,500 compared with $23,150 for the least expensive hospitals ( P <0.001). Postacute care spending among the most expensive hospitals was almost double that of least expensive hospitals ($7,045 vs. $3,742), accounting for 51% of the total difference in episode spending between the most expensive and least expensive hospitals. Female patients, patients with more comorbidities, urban hospitals, and BPCI-A-participating hospitals were associated with significantly increased episode spending, with the effect increasing at the right tail of the spending distribution. CONCLUSION: Inter-hospital variation in 90-day episode spending on sepsis care is driven primarily by differences in post-acute care spending.

Cross-national comparisons of later-life cognitive function using data from the Harmonized Cognitive Assessment Protocol (HCAP): Considerations and recommended best practices.

The Harmonized Cognitive Assessment Protocol (HCAP) is a major innovation that provides, for the first time, harmonized data for cross-national comparisons of later-life cognitive functions that are sensitive to linguistic, cultural, and educational differences across countries. However, cognitive function does not lend itself to direct comparison across diverse populations without careful consideration of the best practices for such comparisons. This perspective discusses theoretical and methodological considerations and offers a set of recommended best practices for conducting cross-national comparisons of risk factor associations using HCAP data. Because existing and planned HCAP studies provide cognition data representing an estimated 75% of the global population ≥65 years of age, these recommended best practices will support high-quality comparative analyses of cognitive aging around the world. The principles described in this perspective are applicable to any researcher aiming to integrate or compare harmonized data on cognitive outcomes and their risk and protective factors across diverse populations.

Educational Attainment and Later-Life Cognitive Function in High- and Middle-Income Countries: Evidence From the Harmonized Cognitive Assessment Protocol.

OBJECTIVES: Identifying social policies that can promote cognitive health is crucial for reducing the global burden of dementia. We evaluated the importance of educational attainment for later-life cognitive function in various social and geographic settings. METHODS: Using harmonized data for individuals aged ≥65 years from the United States Health and Retirement Study (HRS) and its international partner studies in England, Mexico, China, and India, and each study's respective Harmonized Cognitive Assessment Protocol (HCAP), we conducted a cross-national comparative study to examine the role of educational attainment in later-life cognitive function across countries (n = 14,980, 2016-2019). We used multivariable-adjusted regression to estimate associations between educational attainment and harmonized global cognitive function scores. RESULTS: In Mexico, China, and India, the general cognitive function scores on average are approximately one standard deviation of the HRS-HCAP cognitive function score distribution lower compared to the United States and England, paralleling patterns of educational attainment across countries. In all countries, higher educational attainment was associated with progressively higher later-life cognitive function scores. Population-level differences in educational attainment explained about 50%-90% of the observed differences in cognitive function scores across countries. DISCUSSION: The relationship between education and later-life cognitive function across social and geographic contexts underscores the crucial role of education to promote cognitive health and reduce dementia risk. Continual improvement of educational attainment in low- and middle-income settings may yield a significant pay-off in later-life cognitive health.

Factor structure of the Harmonized Cognitive Assessment Protocol neuropsychological battery in the Health and Retirement Study.

OBJECTIVE: The Harmonized Cognitive Assessment Protocol (HCAP) describes an assessment battery and a family of population-representative studies measuring neuropsychological performance. We describe the factorial structure of the HCAP battery in the US Health and Retirement Study (HRS). METHOD: The HCAP battery was compiled from existing measures by a cross-disciplinary and international panel of researchers. The HCAP battery was used in the 2016 wave of the HRS. We used factor analysis methods to assess and refine a theoretically driven single and multiple domain factor structure for tests included in the HCAP battery among 3,347 participants with evaluable performance data. RESULTS: For the eight domains of cognitive functioning identified (orientation, memory [immediate, delayed, and recognition], set shifting, attention/speed, language/fluency, and visuospatial), all single factor models fit reasonably well, although four of these domains had either 2 or 3 indicators where fit must be perfect and is not informative. Multidimensional models suggested the eight-domain model was overly complex. A five-domain model (orientation, memory delayed and recognition, executive functioning, language/fluency, visuospatial) was identified as a reasonable model for summarizing performance in this sample (standardized root mean square residual = 0.05, root mean square error of approximation = 0.05, confirmatory fit index = 0.94). CONCLUSIONS: The HCAP battery conforms adequately to a multidimensional structure of neuropsychological performance. The derived measurement models can be used to operationalize notions of neurocognitive impairment, and as a starting point for prioritizing pre-statistical harmonization and evaluating configural invariance in cross-national research.

Neuropsychological Assessment of Older Adults in Nepal for Population-Based Dementia Ascertainment: Needs, Challenges, and Opportunities.

The population of Nepal is rapidly aging, as in other low and middle-income countries, and the number of individuals living with Alzheimer's Disease and related dementias (ADRD) is expected to increase. However, information about the neuropsychological assessment of ADRD in Nepal is lacking. We first aimed to examine the needs, challenges, and opportunities associated with the neuropsychological assessment of older adults in Nepal for population-based ADRD ascertainment. Second, we introduce the Chitwan Valley Family Study-Study of Cognition and Aging in Nepal (CVFS-SCAN), which is poised to address these needs, and its collaboration with the Harmonized Cognitive Assessment Protocol (HCAP) international network. We reviewed the existing literature on the prevalence, risk factors, available neuropsychological assessment instruments, and sociocultural factors that may influence the neuropsychological assessment of older adults for ADRD ascertainment in Nepal. Our review revealed no existing population-based data on the prevalence of ADRD in Nepal. Very few studies have utilized formal cognitive assessment instruments for ADRD assessment, and there have been no comprehensive neuropsychological assessment instruments that have been validated for the assessment of ADRD in Nepal. We describe how the CVFS-SCAN study will address this need through careful adaptation of the HCAP instrument. We conclude that the development of culturally appropriate neuropsychological assessment instruments is urgently needed for the population-based assessment of ADRD in Nepal. The CVFS-SCAN is designed to address this need and will contribute to the growth of global and equitable neuropsychology and to the science of ADRD in low- and middle-income countries.

Harmonisation of later-life cognitive function across national contexts: results from the Harmonized Cognitive Assessment Protocols.

BACKGROUND: The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonise general and domain-specific cognitive scores from HCAP studies across six countries, and evaluate reliability and criterion validity of the resulting harmonised scores. METHODS: We statistically harmonised general and domain-specific cognitive function scores across publicly available HCAP partner studies in China, England, India, Mexico, South Africa, and the USA conducted between October, 2015 and January, 2020. Participants missing all cognitive test items in a given HCAP were excluded. We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies. We generated harmonised factor scores to represent a person's relative functioning on the latent factors of general cognitive function, memory, executive function, orientation, and language using confirmatory factor analysis. We evaluated the marginal reliability, or precision, of the factor scores using test information plots. Criterion validity of factor scores was assessed by regressing the scores on age, gender, and educational attainment in a multivariable analysis adjusted for these characteristics. FINDINGS: We included 21 144 participants from the six HCAP studies of interest (11 480 women [54·3%] and 9664 [45·7%] men), with a median age of 69 years (IQR 64-76). Confirmatory factor analysis models of cognitive function in each country fit well: 31 (88·6%) of 35 models had adequate or good fit to the data (comparative fit index ≥0·90, root mean square error of approximation ≤0·08, and standardised root mean residual ≤0·08). Marginal reliability of the harmonised general cognitive function factor was high (>0·9) for 19 044 (90·1%) of 21 144 participant scores across the six countries. Marginal reliability of the harmonised factor was above 0·85 for 19 281 (91·2%) of 21 142 participant factor scores for memory, 7805 (41·0%) of 19 015 scores for executive function, 3446 (16·3%) of 21 103 scores for orientation, and 4329 (20·5%) of 21 113 scores for language. In each country, general cognitive function scores were lower with older age and higher with greater levels of educational attainment. INTERPRETATION: We statistically harmonised cognitive function measures across six large population-based studies of cognitive ageing. These harmonised cognitive function scores empirically reflect comparable domains of cognitive function among older adults across the six countries, have high reliability, and are useful for population-based research. This work provides a foundation for international networks of researchers to make improved inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes in pooled analyses. FUNDING: US National Institute on Aging.

Changes in Care Use and Financial Status Associated With Dementia in Older Adults.

Importance: Estimating the effects of dementia on care use and financial outcomes is timely, as the population with dementia will more than double in the next few decades. Objective: To determine the incremental changes associated with dementia in regard to older adults' care use and assess financial consequences for individuals, families, and society. Design, Setting, and Participants: This population-based cohort study included propensity score matching on national, longitudinal data using extensive baseline variables of sociodemographic characteristics, economic status, family availability, health conditions, disability status, and outpatient care use among 2 groups of US adults aged 55 years or older who did not have dementia. In total, 2387 adults experienced the onset of dementia during the 2-year follow-up (dementia group) and 2387 adults did not (control group). Participants were followed up for 8 years from the baseline. Data were analyzed from February 2021 to August 2023. Exposure: Dementia determined based on Langa-Weir classification. Main Outcomes and Measures: Outcomes of care use included monthly care hours from family and unpaid helpers, in-home medical services, hospital stay, and nursing facility stay. Financial outcomes included out-of-pocket medical costs, wealth, and the status of having Medicaid. Results: Among the full sample, the mean (SD) age was 75.4 [10.4] years, and 59.7% of participants were female. Care use was similar at baseline between the matched groups but was substantially greater for the dementia group vs control group in subsequent years, especially during the 2-year follow-up: 45 vs 13 monthly care hours from family and unpaid helpers, 548 of 2370 participants (23.1%) vs 342 of 2383 (14.4%) using in-home medical care, 1104 of 2369 (46.6%) vs 821 of 2377 (34.5%) with hospital stay, and 489 of 2375 (20.6%) vs 104 of 2384 (4.4%) using a nursing facility. The increase in use of a nursing facility was especially high if baseline family care availability was low. Over the 8-year follow-up in the dementia group, the 2-year out-of-pocket medical costs increased from $4005 to $10 006, median wealth was reduced from $79 339 to $30 490, and those enrolling in Medicaid increased from 379 of 2358 participants (16.1%) to 201 of 676 participants (29.7%). No statistically significant changes in financial outcomes were found in the control group. Conclusion and Relevance: This cohort study demonstrated that the incremental changes associated with dementia in regard to older adults' long-term care and financial burden are substantial. Family care availability should be accounted for in a comprehensive assessment of predicting the effects of dementia.

Negative wealth shocks in later life and subsequent cognitive function in older adults in China, England, Mexico, and the USA, 2012-18: a population-based, cross-nationally harmonised, longitudinal study.

BACKGROUND: Household wealth is positively related to cognitive health outcomes in later life. However, the association between negative wealth shocks and cognitive function in later life, and whether this association might differ across countries at different levels of economic development, is unclear. We aimed to investigate whether negative wealth shocks in later life are associated with cognitive function in older adults in China, England, Mexico, and the USA, and whether this association is modified by country income level. METHODS: For this population-based, cross-nationally harmonised, longitudinal study, data were analysed from core interviews of the population-based US Health and Retirement Study (2012 and 2016) and its partner studies in China (the China Health and Retirement Longitudinal Study; 2015 and 2018), England (the English Longitudinal Study of Ageing; 2012 and 2016), and Mexico (Mexican Health and Aging Study; 2012 and 2015-16), and their respective Harmonized Cognitive Assessment Protocols (HCAPs). Negative wealth shocks over the follow-up periods of the respective cohorts were defined in two ways: an extreme loss of 75% or greater from the baseline amount of wealth, and a decline in within-population wealth quintile rank. The primary outcome was the harmonised general cognitive function (GCF) factor score, which was constructed with factor analysis on the HCAP neuropsychological assessments of memory, orientation, attention, executive function, and verbal fluency performance (mean 0; SD 1). We used sampling-weighted, multivariable-adjusted linear models to examine associations. FINDINGS: Data from 9465 participants were included in this analysis: 3796 from China, 1184 from England, 1193 from Mexico, and 3292 from the USA. The mean baseline age of participants was 68·5 (SD 5·4) years in China (49·8% women), 72·0 (7·0) years in England (54·6% women), 70·6 (6·8) years in Mexico (55·1% women), and 72·7 (7·5) years in the USA (60·4% women). A wealth loss of 75% or greater was negatively associated with subsequent cognitive function in the USA (ß -0·16 SD units; 95% CI -0·29 to -0·04) and China (-0·14; -0·21 to -0·07), but not in England (-0·01; -0·24 to 0·22) or Mexico (-0·11; -0·24 to 0·03). Similarly, within-population wealth quintile rank declines were negatively associated with subsequent cognitive function in the USA (ß -0·07 per quintile rank decline; 95% CI -0·11 to -0·03) and China (ß -0·07; -0·09 to -0·04), but not in England (-0·05; -0·11 to 0·01) or Mexico (-0·03; -0·07 to 0·01). INTERPRETATION: The impact of wealth shocks in later life on subsequent lower level of cognitive function of older adults in China, England, Mexico, and the USA differed across macro-level socioeconomic structures. These findings suggest that government policies and social safety nets in countries with different levels of economic development might have a role in protecting older adults from adverse health effects of wealth losses in later life. FUNDING: US National Institute on Aging, US National Institutes of Health.

Lecanemab: Looking Before We Leap.

Lecanemab, a novel amyloid-sequestering agent, recently received accelerated Food and Drug Administration approval for the treatment of mild dementia due to Alzheimer disease (AD) and mild cognitive impairment (MCI). Approval was based on a large phase 3 trial, Clarity, which demonstrated reductions in amyloid plaque burden and cognitive decline with lecanemab. Three major concerns should give us pause before adopting this medication: Its beneficial effects are small, its harms are substantial, and its potential costs are unprecedented. Although lecanemab has a clear and statistically significant effect on cognition, its effect size is small and may not be clinically significant. The magnitude of lecanemab's cognitive effect is smaller than independent estimates of the minimally important clinical difference, implying that the effect may be imperceptible to a majority of patients and caregivers. Lecanemab's cognitive effects were numerically smaller than the effect of cholinesterase inhibitors and may be much smaller. The main argument in lecanemab's favor is that it may lead to greater cognitive benefit over time. Although plausible, there is a lack of evidence to support this conclusion. Lecanemab's harms are substantial. In Clarity, it caused symptomatic brain edema in 11% and symptomatic intracranial bleeding in 0.5% of participants. These estimates likely significantly underestimate these risks in general practice for 3 reasons: (1) Lecanemab likely interacts with other medications that increase bleeding, an effect minimized in Clarity. (2) The Clarity population is much younger than the real-world population with mild AD dementia and MCI (age 71 years vs 85 years) and bleeding risk increases with age. (3) Bleeding rates in trials are typically much lower than in clinical practice. Lecanemab's costs are unprecedented. Its proposed price of $26,500 is based on cost-effectiveness analyses with tenuous assumptions. However, even if cost-effective, it is likely to result in higher expenditures than any other medication. If its entire target population were treated, the aggregate medication expenditures would be $120 billion US dollars per year-more than is currently spent on all medications in Medicare Part D. Before adopting lecanemab, we need to know that lecanemab is not less effective, vastly more harmful, and 100× more costly than donepezil.

Harmonization of Later-Life Cognitive Function Across National Contexts: Results from the Harmonized Cognitive Assessment Protocols (HCAPs).

Background: The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonize general and domain-specific cognitive scores from HCAPs across six countries, and evaluate precision and criterion validity of the resulting harmonized scores. Methods: We statistically harmonized general and domain-specific cognitive function across the six publicly available HCAP partner studies in the United States, England, India, Mexico, China, and South Africa (N=21,141). We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies, as identified by a multidisciplinary expert panel. We generated harmonized factor scores for general and domain- specific cognitive function using serially estimated graded-response item response theory (IRT) models. We evaluated precision of the factor scores using test information plots and criterion validity using age, gender, and educational attainment. Findings: IRT models of cognitive function in each country fit well. We compared measurement reliability of the harmonized general cognitive function factor across each cohort using test information plots; marginal reliability was high (r> 0·90) for 93% of respondents across six countries. In each country, general cognitive function scores were lower with older ages and higher with greater levels of educational attainment. Interpretation: We statistically harmonized cognitive function measures across six large, population-based studies of cognitive aging in the US, England, India, Mexico, China, and South Africa. Precision of the estimated scores was excellent. This work provides a foundation for international networks of researchers to make stronger inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes. Funding: National Institute on Aging (R01 AG070953, R01 AG030153, R01 AG051125, U01 AG058499; U24 AG065182; R01AG051158).

Measurement differences in the assessment of functional limitations for cognitive impairment classification across geographic locations.

INTRODUCTION: The measurement of dementia in cross-national contexts relies on the assessment of functional limitations. We aimed to evaluate the performance of survey items on functional limitations across culturally diverse geographic settings. METHODS: We used data from the Harmonized Cognitive Assessment Protocol Surveys (HCAP) in five countries (total N = 11,250) to quantify associations between items on functional limitations and cognitive impairment. RESULTS: Many items performed better in the United States and England compared to South Africa, India, and Mexico. Items on the Community Screening Instrument for Dementia (CSID) had the least variability across countries (SD = 0.73 vs. 0.92 [Blessed] and 0.98 [Jorm IQCODE]), but also the weakest associations with cognitive impairment (median odds ratio [OR] = 2.23 vs. 3.01 [Blessed] and 2.75 [Jorm IQCODE]). DISCUSSION: Differences in cultural norms for reporting functional limitations likely influences performance of items on functional limitations and may affect the interpretation of results from substantive studies. HIGHLIGHTS: There was substantial cross-country variation in item performance. Items from the Community Screening Instrument for Dementia (CSID) had less cross-country variability but lower performance. There was more variability in performance of instrumental activities of daily living (IADL) compared to activities of daily living (ADL) items. Variability in cultural expectations of older adults should be taken into account. Results highlight the need for novel approaches to assessing functional limitations.

The Influence of Cognitive Impairment on Postoperative Outcomes.

OBJECTIVE: To examine differences in rates of elective surgery, postoperative mortality, and readmission by pre-existing cognitive status among Medicare beneficiaries undergoing surgery. BACKGROUND: MCI is common among older adults, but the impact of MCI on surgical outcomes is understudied. METHODS: We conducted a retrospective cohort study of individuals ≥65 who underwent surgery between 2001 and 2015 using data from the nationally-representative Health and Retirement Study linked with Medicare claims. Cognitive status was assessed by the modified telephone interview for cognitive status score and categorized as normal cognition (score: 12-27), MCI (7-11), and dementia (<7). Outcomes were 30- and 90-day postoperative mortality and readmissions. We used Cox proportional hazard models to estimate the risk of each outcome by cognition, adjusting for patient characteristics. RESULTS: In 6,590 patients, 69.9% had normal cognition, 20.1% had MCI, and 9.9% had dementia. Patients with MCI (79.9%) and dementia (73.6%) were less likely to undergo elective surgery than patients with normal cognition (85.9%). Patients with MCI had similar postoperative mortality and readmissions rates as patients with normal cognition. However, patients with dementia had significantly higher postoperative 90-day mortality (5.2% vs 8.4%, P = 0.002) and readmission rates (13.9% vs 17.3%, P = 0.038). CONCLUSION: Patients with self-reported MCI are less likely to undergo elective surgery but have similar postoperative outcomes compared with patients with normal cognition. Despite the variability of defining MCI, our findings suggest that MCI may not confer additional risk for older individuals undergoing surgery, and should not be a barrier for surgical care.

Association Between Loneliness and Postoperative Mortality Among Medicare Beneficiaries.

This cohort study uses data from the Health and Retirement Study and Medicare claims to examine the association between loneliness and postoperative mortality after elective vs nonelective surgery among older adults.

Time to dementia diagnosis by race: A retrospective cohort study.

BACKGROUND: Non-Hispanic Black individuals may be less likely to receive a diagnosis of dementia compared to non-Hispanic White individuals. These findings raise important questions regarding which factors may explain this observed association and any differences in the time to which disparities emerge following dementia onset. METHODS: We conducted a retrospective cohort study using survey data from the 1995 to 2016 Health and Retirement Study linked with Medicare fee-for-service claims. Using the Hurd algorithm (a regression-based approach), we identified dementia onset among older adult respondents (age ≥65 years) from the Telephone Interview for Cognitive Status and proxy respondents. We determined date from dementia onset to diagnosis using Medicare data up to 3 years following onset using a list of established diagnosis codes. Cox Proportional Hazards modeling was used to examine the association between an individual's reported race and likelihood of diagnosis after accounting for sociodemographic characteristics, income, education, functional status, and healthcare use. RESULTS: We identified 3435 older adults who experienced a new onset of dementia. Among them, 30.1% received a diagnosis within 36 months of onset. In unadjusted analyses, the difference in cumulative proportion diagnosed by race continued to increase across time following onset, p-value <0.001. 23.8% of non-Hispanic Black versus 31.4% of non-Hispanic White participants were diagnosed within 36 months of dementia onset, Hazard Ratio = 0.73 (95% CI: 0.61, 0.88). The association persisted after adjustment for functional status and healthcare use; however, these factors had less of an impact on the strength of the association than income and level of education. CONCLUSION: Lower diagnosis rates of dementia among non-Hispanic Black individuals persists after adjustment for sociodemographic characteristics, functional status, and healthcare use. Further understanding of barriers to diagnosis that may be related to social determinants of health is needed to improve dementia-related outcomes among non-Hispanic Black Americans.

Widowhood and cognition among older women in India: New insights on widowhood duration and mediators.

Background: Widowhood, a marital status that disproportionately affects older women, has been associated with poorer health compared to married individuals. However, relatively little is known about the association between widowhood in later-life and cognitive health in low- and middle-income countries. Methods: To address this research gap, we used data from the Longitudinal Aging Study in India (2017-19) to investigate the widowhood disparity in cognitive health among mid-aged and older women in India, including how this relationship varies by the duration of widowhood. We further examined the extent to which economic, social, and health conditions mediate this association. Results: Cognition scores for widowed women were on average lower by almost 0.1 standard deviations compared to married women. Overall, this disparity increased with widowhood duration, with non-linearities in this association. The disparity in cognition scores increased with widowhood duration up to twenty years but did not increase further among those with longer widowhood duration. Worse physical and mental health were found to mediate almost thirty percent of the total association between widowhood and cognition. These mediators were most useful in explaining the association between lower cognition and widowhood among women who experienced widowhood for ten years or longer. Conclusion: The study highlights the significant disadvantage in cognitive functioning among older widowed women in India. The study also provides evidence on potential mediators, suggesting differential effects of mediators at different stages of widowhood.

Estimating the Prevalence of Dementia and Mild Cognitive Impairment in the US: The 2016 Health and Retirement Study Harmonized Cognitive Assessment Protocol Project.

Importance: Nationally representative data are critical for understanding the causes, costs, and outcomes associated with dementia and mild cognitive impairment (MCI) in the US and can inform policies aimed at reducing the impact of these conditions on patients, families, and public programs. The nationally representative Health and Retirement Study (HRS) is an essential resource for such data, but the HRS substudy providing dementia diagnostic information was fielded more than 20 years ago and more recent data are needed. Objective: The Harmonized Cognitive Assessment Protocol (HCAP) was developed to update national estimates of the prevalence of MCI and dementia in the US and examine differences by age, race, ethnicity, and sex. Design, Setting, and Participants: HRS is an ongoing longitudinal nationally representative study of people 51 years and older with staggered entry dates from 1992 to 2022 and follow-up ranging from 4 to 30 years. HCAP is a cross-sectional random sample of individuals in HRS who were 65 years or older in 2016. Of 9972 age-eligible HRS participants, 4425 were randomly selected for HCAP, and 3496 completed a comprehensive neuropsychological test battery and informant interview, none of whom were excluded. Dementia and MCI were classified using an algorithm based on standard diagnostic criteria and comparing test performance to a robust normative sample. Exposures: Groups were stratified by age, sex, education, race, and ethnicity. Main Outcomes and Measures: National prevalence estimates using population weights. Results: The mean (SD) age of the study population sample (N = 3496) was 76.4 (7.6) years, and 2095 participants (60%) were female. There were 551 participants who self-identified as Black and not Hispanic (16%), 382 who self-identified as Hispanic regardless of race (16%), 2483 who self-identified as White and not Hispanic (71%), and 80 who self-identified as another race (2%), including American Indian or Alaska Native, Asian, Native Hawaiian or Pacific Islander, or another self-described race. A total of 393 individuals (10%; 95% CI, 9-11) were classified as having dementia and 804 (22%; 95% CI, 20-24) as having MCI. Every 5-year increase in age was associated with higher risk of dementia (weighted odds ratio [OR], 1.95 per 5-year age difference; 95%, CI, 1.77-2.14) and MCI (OR, 1.17 per 5-year age difference, 95% CI, 1.09-1.26). Each additional year of education was associated with a decrease in risk of dementia (OR, 0.93 per year of school, 95% CI, 0.89-0.97) and MCI (OR, 0.94, 95% CI, 0.91-0.97). Dementia was more common among non-Hispanic Black individuals (OR, 1.81; 95% CI, 1.20-2.75) and MCI in Hispanic individuals (OR, 1.42; 95% CI, 1.03-1.96) compared with non-Hispanic White individuals. Other group comparisons by race and ethnicity were not possible owing to small numbers. No differences in prevalence were found between female individuals and male individuals. Conclusions and Relevance: Using a comprehensive neuropsychological test battery and large sample, the national prevalence of dementia and MCI in 2016 found in this cross-sectional study was similar to that of other US-based studies, indicating a disproportionate burden of dementia and MCI among older Black and Hispanic adults and those with lower education.

Cognability: An Ecological Theory of neighborhoods and cognitive aging.

While a growing body of evidence points to potentially modifiable individual risk factors for dementia, the built and social environments in which people develop and navigate cognitive decline are largely overlooked. This paper proposes a new theoretical concept, Cognability, to conceptualize how supportive an area is to cognitive health among aging residents. Cognability incorporates a constellation of both positive and negative neighborhood features related to physical activity, social interaction and cognitive stimulation in later life. We analyzed data from the REasons for Geographic And Racial Differences in Stroke Study, a national sample of older Black and white adults in the United States (n = 21,151; mean age at assessment = 67; data collected 2006-2017). Generalized additive multilevel models examined how cognitive function varied by neighborhood features. Access to civic and social organizations, recreation centers, fast-food and coffee establishments, arts centers, museums, and highways were significantly associated with cognitive function. Race-, gender-, and education-specific models did not yield substantial improvements to the full-model. Our results suggest that the unequal distribution of amenities and hazards across neighborhoods may help account for considerable inequities observed in cognitive health among older adults. Cognability advances ecological theories of aging through an innovative "whole neighborhood" approach. It aims to identify which specific neighborhood features are most protective of cognitive health among aging adults to inform upstream public health initiatives, community interventions, and policy.

Differences in the measurement of cognition for the assessment of dementia across geographic contexts: Recommendations for cross-national research.

INTRODUCTION: Most cognitive assessments have been developed in high-income countries but are used in diverse contexts. Differences in culture and context may affect the performance of cognitive items. METHODS: We used the Harmonized Cognitive Assessment Protocol (HCAP) surveys in the United States, Mexico, India, England, and South Africa (combined N = 11,364) to quantify associations across countries between cognitive items and cognitive impairment status using age- and sex-adjusted logistic regression. RESULTS: Associations were stronger in the United States (median odds ratio [OR] across items = 0.17) and England (median OR = 0.19), compared to South Africa (median OR = 0.23), India (median OR = 0.29), and Mexico (median OR = 0.28). Items assessing memory (e.g., delayed recall tasks) had the most consistent associations of the largest magnitudes across contexts. DISCUSSION: Transporting cognitive items among countries and cultures warrants caution. Our results can guide the design of future instruments by identifying items that performed well either in individual contexts or across the range of contexts considered. HIGHLIGHTS: Little quantitative evidence exists to guide the design of cognitive assessments in cross-national studies. The performance of cognitive items for the measurement of dementia varied across countries. Items with lower variation across countries (e.g., delayed word recall) should be used in future cross-national assessments. Across countries, there was variability in the performance of language assessments, with the exception of the animal naming task. Results can be used to design future cross-national or location-specific cognitive assessments.