Multi-Ethnic Norms for Volumes of Subcortical and Lobar Brain Structures Measured by Neuro I: Ethnicity May Improve the Diagnosis of Alzheimer's Disease1.

Background: We previously demonstrated the validity of a regression model that included ethnicity as a novel predictor for predicting normative brain volumes in old age. The model was optimized using brain volumes measured with a standard tool FreeSurfer. Objective: Here we further verified the prediction model using newly estimated brain volumes from Neuro I, a quantitative brain analysis system developed for Korean populations. Methods: Lobar and subcortical volumes were estimated from MRI images of 1,629 normal Korean and 786 Caucasian subjects (age range 59-89) and were predicted in linear regression from ethnicity, age, sex, intracranial volume, magnetic field strength, and scanner manufacturers. Results: In the regression model predicting the new volumes, ethnicity was again a substantial predictor in most regions. Additionally, the model-based z-scores of regions were calculated for 428 AD patients and the matched controls, and then employed for diagnostic classification. When the AD classifier adopted the z-scores adjusted for ethnicity, the diagnostic accuracy has noticeably improved (AUC = 0.85, ΔAUC = + 0.04, D = 4.10, p < 0.001). Conclusions: Our results suggest that the prediction model remains robust across different measurement tool, and ethnicity significantly contributes to the establishment of norms for brain volumes and the development of a diagnostic system for neurodegenerative diseases.

Strategies for Recruiting Older Black Men into Aging and Alzheimer's Research.

BACKGROUND: Despite their high risks for Alzheimer's disease, older Black men are minimally represented in Alzheimer's research and clinical trials. The absence of older Black men in Alzheimer's research limits our ability to characterize the changes associated with cognitive impairments in older Black men-a key health disparity concern. METHODS: Drawing on lessons we learned from years of community-based participatory research in Newark, NJ, we highlight recruitment strategies developed alongside community partners to guide our enrollment and retention efforts for Black men. RESULTS: We identified seven recruitment strategies: provide indirect health education through social programming, target older men through the younger men in their lives, go beyond Black churches, use older Black men as trained community ambassadors, enlist the women in Black men's lives, frame research participation as a legacy to leave their sons, and use past and current Black men participants as role models. CONCLUSIONS: These recruitment strategies help us address many barriers to recruiting older Black men. They can be easily implemented by researchers conducting aging and brain health research or interested in working with older Black men and under-represented populations.

DNA methylation of imprint control regions associated with Alzheimer's disease in non-Hispanic Blacks and non-Hispanic Whites.

Alzheimer's disease (AD) prevalence is twice as high in non-Hispanic Blacks (NHBs) as in non-Hispanic Whites (NHWs). The objective of this study was to determine whether aberrant methylation at imprint control regions (ICRs) is associated with AD. Differentially methylated regions (DMRs) were bioinformatically identified from whole-genome bisulfite sequenced DNA derived from brain tissue of 9 AD (5 NHBs and 4 NHWs) and 8 controls (4 NHBs and 4 NHWs). We identified DMRs located within 120 regions defined as candidate ICRs in the human imprintome ( https://genome.ucsc.edu/s/imprintome/hg38.AD.Brain_track ). Eighty-one ICRs were differentially methylated in NHB-AD, and 27 ICRs were differentially methylated in NHW-AD, with two regions common to both populations that are proximal to the inflammasome gene, NLRP1, and a known imprinted gene, MEST/MESTIT1. These findings indicate that early developmental alterations in DNA methylation of regions regulating genomic imprinting may contribute to AD risk and that this epigenetic risk differs between NHBs and NHWs.

Racial, ethnic, and rural disparities in distance to physicians among decedents with Alzheimer's disease and related dementias in Washington State.

INTRODUCTION: Distance to physicians may explain some of the disparities in Alzheimer's disease and related dementia (AD/ADRD) outcomes. METHODS: We generated round trip distance between residences of decedents with AD/ADRD and the nearest neurologist and primary care physician in Washington State. RESULTS: The overall mean distance to the nearest neurologist and primary care physician was 17 and 4 miles, respectively. Non-Hispanic American Indian and/or Alaska Native and Hispanic decedents would have had to travel 1.12 and 1.07 times farther, respectively, to reach the nearest neurologist compared to non-Hispanic White people. Decedents in micropolitan, small town, and rural areas would have had to travel 2.12 to 4.01 times farther to reach the nearest neurologist and 1.14 to 3.32 times farther to reach the nearest primary care physician than those in metropolitan areas. DISCUSSION: These results underscore the critical need to identify strategies to improve access to specialists and primary care physicians to improve AD/ADRD outcomes. HIGHLIGHTS: Distance to neurologists and primary care physicians among decedents with AD/ADRD American Indian and/or Alaska Native decedents lived further away from neurologists Hispanic decedents lived further away from neurologists Non-metropolitan decedents lived further away from neurologists and primary care Decrease distance to physicians to improve dementia outcomes.

Algorithmic Fairness of Machine Learning Models for Alzheimer Disease Progression.

Importance: Predictive models using machine learning techniques have potential to improve early detection and management of Alzheimer disease (AD). However, these models potentially have biases and may perpetuate or exacerbate existing disparities. Objective: To characterize the algorithmic fairness of longitudinal prediction models for AD progression. Design, Setting, and Participants: This prognostic study investigated the algorithmic fairness of logistic regression, support vector machines, and recurrent neural networks for predicting progression to mild cognitive impairment (MCI) and AD using data from participants in the Alzheimer Disease Neuroimaging Initiative evaluated at 57 sites in the US and Canada. Participants aged 54 to 91 years who contributed data on at least 2 visits between September 2005 and May 2017 were included. Data were analyzed in October 2022. Exposures: Fairness was quantified across sex, ethnicity, and race groups. Neuropsychological test scores, anatomical features from T1 magnetic resonance imaging, measures extracted from positron emission tomography, and cerebrospinal fluid biomarkers were included as predictors. Main Outcomes and Measures: Outcome measures quantified fairness of prediction models (logistic regression [LR], support vector machine [SVM], and recurrent neural network [RNN] models), including equal opportunity, equalized odds, and demographic parity. Specifically, if the model exhibited equal sensitivity for all groups, it aligned with the principle of equal opportunity, indicating fairness in predictive performance. Results: A total of 1730 participants in the cohort (mean [SD] age, 73.81 [6.92] years; 776 females [44.9%]; 69 Hispanic [4.0%] and 1661 non-Hispanic [96.0%]; 29 Asian [1.7%], 77 Black [4.5%], 1599 White [92.4%], and 25 other race [1.4%]) were included. Sensitivity for predicting progression to MCI and AD was lower for Hispanic participants compared with non-Hispanic participants; the difference (SD) in true positive rate ranged from 20.9% (5.5%) for the RNN model to 27.8% (9.8%) for the SVM model in MCI and 24.1% (5.4%) for the RNN model to 48.2% (17.3%) for the LR model in AD. Sensitivity was similarly lower for Black and Asian participants compared with non-Hispanic White participants; for example, the difference (SD) in AD true positive rate was 14.5% (51.6%) in the LR model, 12.3% (35.1%) in the SVM model, and 28.4% (16.8%) in the RNN model for Black vs White participants, and the difference (SD) in MCI true positive rate was 25.6% (13.1%) in the LR model, 24.3% (13.1%) in the SVM model, and 6.8% (18.7%) in the RNN model for Asian vs White participants. Models generally satisfied metrics of fairness with respect to sex, with no significant differences by group, except for cognitively normal (CN)-MCI and MCI-AD transitions (eg, an absolute increase [SD] in the true positive rate of CN-MCI transitions of 10.3% [27.8%] for the LR model). Conclusions and Relevance: In this study, models were accurate in aggregate but failed to satisfy fairness metrics. These findings suggest that fairness should be considered in the development and use of machine learning models for AD progression.

Perspectives From Black and White Participants and Care Partners on Return of Amyloid and Tau PET Imaging and Other Research Results.

PURPOSE: Alzheimer disease (AD) biomarker testing is now common in research and approaching clinical translation. Disclosure protocols must be informed by diverse participants' perspectives on if/how the information would be useful. METHODS: This study utilized semistructured interviews assessing interest in receiving positron emission tomography (PET) amyloid and tau results, as well as perceived risks and benefits of hypothetical PET disclosure as a function of race and participant diagnosis. PARTICIPANTS: Participants [39% Black; 61% White; Mage =74.28 (5.98)] included 57 adults diagnosed as either cognitively healthy (58%) or with mild cognitive impairment (42%) and their respective care partners [33% Black; 67% White; Mage =66.93 (10.92)]. RESULTS: Most dyads endorsed strong interest in PET results (82.5% of both participants and partners) regardless of race or diagnosis. Black care partners were less interested in receiving the participant's results than White care partners ( χ2(4) =8.31, P =0.047). Reasons for disclosure were diverse and highly personalized, including access to treatments or clinical trials (23.2% participants; 29.8% partners), advance planning (14.3% participants; 17.5% partners), and improved health knowledge (12.5% participants; 15.8% partners). In contrast, over 80% of respondents denied any risks of disclosure. DISCUSSION: Results suggest that predisclosure education, decisional capacity assessment, and a flexible disclosure approach are needed.

Development of a Mobile-First Registry to Recruit Healthy Volunteers and Members of Underrepresented Communities for Alzheimer's Disease Prevention Studies.

BACKGROUND: Web-based participant recruitment registries can be useful tools for accelerating enrollment into studies, but existing Alzheimer's disease (AD)-focused recruitment registries have had limited success enrolling individuals from underrepresented racial and ethnic groups. Designing these registries to meet the needs of individuals from these communities, including designing mobile-first, may facilitate improvement in the enrollment of underrepresented groups. OBJECTIVES: Evaluate the usability of a prototype mobile-first participant recruitment registry for AD prevention studies; assess users' perceptions of and willingness to sign up for the registry. DESIGN AND SETTING: Quantitative usability testing and an online survey; online setting. PARTICIPANTS: We recruited 1,358 adults ages 45-75 who self-reported not having a diagnosis of mild cognitive impairment, AD, or other forms of dementia (Study 1: n=589, Study 2: n=769). Black/African American and Hispanic/Latino participants were specifically recruited, including those with lower health literacy. METHODS AND MEASUREMENTS: Study 1 measures the prototype's usability through observed task success rates, task completion times, and responses to the System Usability Scale. Study 2 uses an online survey to collect data on perceptions of and willingness to sign up for the mobile-first registry. RESULTS: Study 1 findings show the prototype mobile-first recruitment registry website demonstrates high usability and is equally usable for Black / African American, Hispanic/Latino, and White user groups. Survey results from Study 2 indicate that users from underrepresented communities understand the registry's purpose and content and express willingness to sign up for the registry on a mobile device. CONCLUSIONS: Designing mobile-first participant recruitment registries based on feedback from underrepresented communities may result in more sign-ups by individuals from minoritized communities.

Understanding Barriers and Facilitators to Signing Up for a Mobile-Responsive Registry to Recruit Healthy Volunteers and Members of Underrepresented Communities for Alzheimer's Disease Prevention Studies.

BACKGROUND: Alzheimer's disease (AD) disproportionately affects Black/African American and Hispanic/Latino adults, yet they are underrepresented in AD studies. Recruitment challenges for these populations limit generalizability of findings. OBJECTIVES: This study explores barriers and facilitators to signing up for an AD participant recruitment registry website intended to optimize recruitment of these adults. The registry is geared toward recruitment on smartphones and tablets (mobile devices), as research suggests that mobile-first approaches may be more successful within these populations. DESIGN: In 2020, we conducted four focus groups (n = 39) and an online survey (n = 1010) with Black/African American and Hispanic/Latino adults. The survey also included Whites as a comparison group. SETTING: Focus groups were in-person at research facilities in New Orleans, Louisiana, and Los Angeles, California. The online survey was distributed by a survey panel company to participants nationwide. PARTICIPANTS: Black/African American (n = 360), Hispanic/Latino (n = 359), or White (n = 330) individuals, 45-75 years old, who self-reported not having mild cognitive impairment (MCI), dementia, or AD. MEASUREMENTS: Barriers and facilitators explored in the focus groups and survey were related to health and AD (e.g., AD-related concerns and past participation/willingness to participate in health or AD studies); current use of mobile devices (e.g., comfort using devices and receptivity to the AD recruitment registry); and participant characteristics and beliefs (e.g., demographics, health literacy level, and trust in government and the scientific community). RESULTS: The focus groups and survey revealed similar findings. Participants commonly use mobile devices to go online and perform health-related activities. They were aware of AD, expressed concerns with developing it, and were willing to participate in AD-related studies (motivated by personal connection to AD, altruism, and compensation). When presented with the AD recruitment registry, most provided positive feedback (e.g., easy to use and informative) and shared an interest in joining. Barriers to joining the registry with a mobile device included complex or multistep enrollment processes, beliefs that studies are primarily for those with a specific disease, and confusion about how studies can prevent AD among those low-risk for AD. The focus groups also revealed that Black/African American participants expressed more hesitation than Hispanic/Latinos in joining the registry due to greater distrust in the government and scientific community. CONCLUSIONS: Recruiting more Black/African American and Hispanic/Latino participants into AD studies is vitally important. This mixed methods study suggests that adults in these underrepresented groups are motivated to prevent AD and willing to sign up for an AD participant recruitment registry using mobile devices. Most barriers to joining a registry can be addressed through slight modifications to the registry's design and functionality and by adding content. These findings can help enhance the appeal of joining AD recruitment registries to ultimately enroll more diverse, representative groups of participants and increase the generalizability of AD study findings.

Development of a Culturally Adapted Dietary Intervention to Reduce Alzheimer's Disease Risk among Older Black Adults.

The objective of this study is to identify and understand knowledge and attitudes that influence dietary practices among older Black adults using a community-engaged approach. This is a non-interventional mixed methods study designed to inform the development of an adapted brain-healthy soul food diet intervention. A purposive sampling approach was used to conduct seven semi-structured focus group discussions and an online quantitative survey. In total, 39 participants who self-identified as Black, aged 55 years and older, English speaking, and who were cognitively normal with an AD8 < 2; (25.6% men; 74.4% women) participated in the online survey and one of the seven 60 min virtual focus group discussions (5-7 per focus group). Quantitative frequency data from the online surveys were analyzed using descriptive statistics. Qualitative focus group data were analyzed using a 6-step thematic analysis process. Five themes emerged: dementia awareness; practices shaping food choices and consumption; barriers to eating healthy; instrumental support; and elements of a culturally adapted brain-healthy dietary intervention. Older Black adults perceived an adapted MIND dietary model as the most acceptable with the incorporation of salient cultural characteristics and strategies within both the design and delivery phases.

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.

Alzheimer's disease and its related dementias in US Native Americans: A major public health concern.

Alzheimer's disease (AD) and Alzheimer's related dementias (ADRD) are growing public health concerns in aged populations of all ethnic and racial groups. AD and ADRD are caused by multiple factors, such as genetic mutations, modifiable and non-modifiable risk factors, and lifestyle. Studies of postmortem brains have revealed multiple cellular changes implicated in AD and ADRD, including the accumulation of amyloid beta and phosphorylated tau, synaptic damage, inflammatory responses, hormonal imbalance, mitochondrial abnormalities, and neuronal loss. These changes occur in both early-onset familial and late-onset sporadic forms. Two-thirds of women and one-third of men are at life time risk for AD. A small proportion of total AD cases are caused by genetic mutations in amyloid precursor protein, presenilin 1, and presenilin 1 genes, and the APOE4 allele is a risk factor. Tremendous research on AD/ADRD, and other comorbidities such as diabetes, obesity, hypertension, and cancer has been done on almost all ethnic groups, however, very little biomedical research done on US Native Americans. AD/ADRD prevalence is high among all ethnic groups. In addition, US Native Americans have poorer access to healthcare and medical services and are less likely to receive a diagnosis once they begin to exhibit symptoms, which presents difficulties in treating Alzheimer's and other dementias. One in five US Native American people who are 45 years of age or older report having memory issues. Further, the impact of caregivers and other healthcare aspects on US Native Americans is not yet. In the current article, we discuss the history of Native Americans of United States (US) and health disparities, occurrence, and prevalence of AD/ADRD, and shedding light on the culturally sensitive caregiving practices in US Native Americans. This article is the first to discuss biomedical research and healthcare disparities in US Native Americans with a focus on AD and ADRD, we also discuss why US Native Americans are reluctant to participate in biomedical research.

Intersectionality in Alzheimer's Disease: The Role of Female Sex and Black American Race in the Development and Prevalence of Alzheimer's Disease.

It is well known that vascular factors and specific social determinants of health contribute to dementia risk and that the prevalence of these risk factors differs according to race and sex. In this review, we discuss the intersection of sex and race, particularly female sex and Black American race. Women, particularly Black women, have been underrepresented in Alzheimer's disease clinical trials and research. However, in recent years, the number of women participating in clinical research has steadily increased. A greater prevalence of vascular risk factors such as hypertension and type 2 diabetes, coupled with unique social and environmental pressures, puts Black American women particularly at risk for the development of Alzheimer's disease and related dementias. Female sex hormones and the use of hormonal birth control may offer some protective benefits, but results are mixed, and studies do not consistently report the demographics of their samples. We argue that as a research community, greater efforts should be made to not only recruit this vulnerable population, but also report the demographic makeup of samples in research to better target those at greatest risk for the disease.

Suspected Undiagnosed ADRD Among Middle Eastern and North African Americans.

ADRD underdiagnosis among minority populations is well-established and known to be more prevalent among women. Yet, it remains unclear if these patterns exist among adults of Middle Eastern and North African (MENA) descent. We estimated ADRD underdiagnosis among adults of MENA descent and other US- and foreign-born non-Hispanic Whites and compared sex-stratified results. We linked 2000-2017 National Health Interview Survey and 2001-2018 Medical Expenditure Panel Survey data (ages > = 65 years, n = 23,981). Undiagnosed ADRD was suspected if participants reported cognitive limitations without corresponding ADRD diagnosis. Undiagnosed ADRD was highest among adults of MENA descent (15.8%) compared to non-Hispanic Whites (US-born = 8.1%; foreign-born = 11.8%). Women of MENA descent had 2.52 times greater odds (95% CI = 1.31-4.84) of undiagnosed ADRD compared to US-born White women after adjusting for risk factors. This study contributes the first national estimates of undiagnosed ADRD among adults of MENA descent. Continued research is needed to facilitate policy changes that more comprehensively address health disparities and related resource allocation.

Multi-ancestry meta-analysis and fine-mapping in Alzheimer's disease.

Genome-wide association studies (GWAS) of Alzheimer's disease are predominantly carried out in European ancestry individuals despite the known variation in genetic architecture and disease prevalence across global populations. We leveraged published GWAS summary statistics from European, East Asian, and African American populations, and an additional GWAS from a Caribbean Hispanic population using previously reported genotype data to perform the largest multi-ancestry GWAS meta-analysis of Alzheimer's disease and related dementias to date. This method allowed us to identify two independent novel disease-associated loci on chromosome 3. We also leveraged diverse haplotype structures to fine-map nine loci with a posterior probability >0.8 and globally assessed the heterogeneity of known risk factors across populations. Additionally, we compared the generalizability of multi-ancestry- and single-ancestry-derived polygenic risk scores in a three-way admixed Colombian population. Our findings highlight the importance of multi-ancestry representation in uncovering and understanding putative factors that contribute to risk of Alzheimer's disease and related dementias.

Trends in Alzheimer Disease Mortality Among American Indian and Alaska Native People Between 2011 and 2019.

PURPOSE: The number of American Indian and Alaska Native (AI/AN) people living with dementia is expected to increase 5-fold by 2060. Social determinants of health may explain disparities in the incidence of Alzheimer disease (AD) but remain largely overlooked. METHODS: We examined the time trend of AD mortality rates and associations of the percentage of AI/ANs, density of primary care physicians and neurologists, area deprivation index, rurality, and Indian Health Service region with AD mortality in 646 purchased/referred care delivery area counties. RESULTS: AD mortality rates significantly increased over time. Counties with higher concentrations of AI/AN people had lower AD mortality. More deprived counties had 34% higher AD mortality compared with less deprived counties. AD mortality was 20% lower in nonmetro counties than in metro counties. CONCLUSIONS: Findings have implications for prioritizing areas where more resources for AD care, education, or outreach are needed.

High-Quality Sleep Mitigates ABCA7-Related Generalization Deficits in Healthy Older African Americans.

BACKGROUND: Both sleep deficiencies and Alzheimer's disease (AD) disproportionately affect older African Americans. Genetic susceptibility to AD further compounds risk for cognitive decline in this population. Aside from APOE ɛ4, ABCA7 rs115550680 is the strongest genetic locus associated with late-onset AD in African Americans. While sleep and ABCA7 rs115550680 independently influence late-life cognitive outcomes, we know too little about the interplay between these two factors on cognitive function. OBJECTIVE: We investigated the interaction between sleep and ABCA7 rs115550680 on hippocampal-dependent cognitive function in older African Americans. METHODS: One-hundred fourteen cognitively healthy older African Americans were genotyped for ABCA7 risk (n = 57 carriers of risk "G" allele; n = 57 non-carriers), responded to lifestyle questionnaires, and completed a cognitive battery. Sleep was assessed via a self-reported rating of sleep quality (poor, average, good). Covariates included age and years of education. RESULTS: Using ANCOVA, we found that carriers of the risk genotype who reported poor or average sleep quality demonstrated significantly poorer generalization of prior learning-a cognitive marker of AD-compared to their non-risk counterparts. Conversely, there was no genotype-related difference in generalization performance in individuals who reported good sleep quality. CONCLUSION: These results indicate that sleep quality may be neuroprotective against genetic risk for AD. Future studies employing more rigorous methodology should investigate the mechanistic role of sleep neurophysiology in the pathogenesis and progression of AD associated with ABCA7. There is also need for the continued development of non-invasive sleep interventions tailored to racial groups with specific AD genetic risk profiles.

The Senior Companion Program Plus (SCP Plus): Examining the Preliminary Effectiveness of a Lay Provider Program to Support African American Alzheimer's Disease and Related Dementias (ADRD) Caregivers.

OBJECTIVES: A culturally informed, peer-led, lay provider model, the Senior Companion Program (SCP) Plus, was implemented to decrease caregiving burden/stress and improve coping skills and social support for African American ADRD caregivers. This study reported the preliminary effectiveness of this intervention. METHODS: An explanatory sequential mixed methods design was used in this study, and a randomized control trial was conducted for the SCP Plus intervention among participants in three sites (n = 20). A subsample of participants (n = 7) consented to a qualitative interview about their experiences with the intervention. Wilcoxon signed-rank tests, Friedman tests, and one-way repeated measures ANOVA were computed for quantitative analyses. Thematic analysis was used for the qualitative interviews. RESULTS: Results demonstrated that knowledge of AD/dementia (KAD) and preparedness for caregiving were significantly improved for all senior companions in the intervention group. Results also showed that caregivers in the intervention group reported significantly decreased caregiving burden, as well as increased KAD, satisfaction with social support, and positive aspects of caregiving. Themes from the qualitative interviews included: learning new skills about caregiving, gaining knowledge about ADRD, and benefits for the dyad. DISCUSSIONS: Findings from this study implied that SCP Plus was a promising model for African American family caregivers as it benefits both the SC volunteers and the African American ADRD family caregivers.

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.

The Positive Aspects of Caregiving Scale can be shortened to six items: application of item response theory.

OBJECTIVE: For nearly two decades, with one exception, researchers have used the Positive Aspects of Caregiving Scale (PACS) without a close examination of how the items behave. This study examined PACS' measurement model and item response characteristics, including differential item functioning (DIF) by race. METHODS: Item response theory was used to analyze the baseline data of the Resources for Enhancing Alzheimer's Caregiver Health (REACH) I trial (N = 1229). Bifactor confirmatory models were estimated to assess dimensionality, and whether the items behaved differently in African Americans and Hispanics, with Whites serving as the comparison, were examined using the multiple-indicators multiple-causes model. RESULTS: For both 9- and 11-item versions, 1-factor and bifactor solutions supported a unidimensional structure. However, the items performed generally poorly in differentiating levels of the latent construct, especially between moderate and high true scores. Additionally, five items were found to have DIF, which were unrelated to relationship differences among racial groups. While African Americans and Hispanics reported higher positive gains than Whites, their differences were accentuated by the DIF items as a whole. A 6-item version called PACS-II was created by removing the DIF items. Besides reducing estimated racial differences, PACS-II removed race-based heterogeneity of variance that was evidenced in the original, longer versions. CONCLUSIONS: Being free of racial bias, PACS-II is preferred over the original versions, though the ceiling effect of measurement (prevalence of extreme scores on the high end) remains to be an issue for improvement.