Recruitment of a Diverse Community-based Older Adult Cohort for a Longitudinal Aging Study: The 15104 Seniors Project.

INTRODUCTION: Enrolling individuals from underrepresented ethnoracial groups in aging research is often a challenge. METHODS: We sought a diverse sample of older adults from a small-town area for a longitudinal aging study. We employed an intensive community engagement approach encompassing a range of recruitment strategies. RESULTS: Over 4 years a steady trickle of individuals, 66% self-identifying as Black, signed up for study information; the proportion of those who eventually enroll in the study has been rising each year, from 68% to 94%. Community events, word-of-mouth referrals, and mailed postcards brought in the most contacts. The highest percentage of contacts who ultimately enrolled were from postcards, flyers, and word-of-mouth. Significantly more word-of-mouth referrals were endorsed by Black individuals than White and by Black men than other race/sex groups. CONCLUSIONS: We have had some success in building relationships and trust with the local community, enrolling Black study participants in a proportion equal to their representation in the target community using a variety of recruitment methods. Patience, immersion in the community, and partnerships with key community members alongside traditional advertisements, and the utilization of study participants as recruiters are critical to designing optimal, targeted, recruitment strategies.

Ethnoracial Identity and Cognitive Impairment: A Community Study.

BACKGROUND: Identifying potentially modifiable risk factors associated with MCI in different ethnoracial groups could reduce MCI burden and health inequity in the population. METHODS: Among 2845 adults aged 65+ years, we investigated potential risk exposures including education, physical and mental health, lifestyle, and sensory function, and their cross-sectional associations with MCI. We compared proportions of exposures between Black and White participants and explored relationships among race, MCI, and exposures. Logistic regression modeled MCI as a function of each exposure in the overall sample adjusting for age, sex, educational level, and race, and investigating race*exposure interactions. RESULTS: Compared with White participants, Black participants had greater odds of MCI (OR 1.53; 95% CI, 1.13 to 2.06) and were more likely to report depressive symptoms, diabetes, and stroke, to have high blood pressure and BMI, and to be APOE - 4 carriers. Exposures associated with higher odds of MCI were diabetes, stroke, lifetime smoking, sleep disturbances, social isolation, loneliness, depression and anxiety symptoms, and vision and hearing loss. There were no significant interactions between race and any exposure. CONCLUSIONS: Black participants had 53% higher odds of MCI adjusting for age, sex, and education. The same exposures were associated with MCI in Black and White participants.

Marijuana use among community-dwelling older adults: A population-based study.

OBJECTIVES: There is a paucity of population-level data on marijuana use and mental health and functioning in older adults. METHODS: We analyzed cross-sectional data (n = 910) from a well-characterized cohort, the Monongahela-Youghiogheny Healthy Aging Team (MYHAT) study. MYHAT is an age-stratified random sample of the population age 65 years and older from a small-town in the USA. Half the sample was female and half were over 75 (Mean age = 77). Most participants were non-Hispanic White. Marijuana use was assessed by self-report and symptoms of mood disorders were screened using the modified Centers for Epidemiological Studies-Depression Scale and the Generalized Anxiety Disorder screener. Cognition was assessed by the Mini-Mental State Examination and a neuropsychological test battery; functioning using the OARS Activities of Daily Living and Instrumental Activities of Daily Living; and overall assessment using the Clinical Dementia Rating (CDR®). RESULTS: One in five MYHAT participants had a history of marijuana use and 5% reported recent use, primarily for pain (41%) and recreation/relaxation (37%). Recent use was associated with cigarette and alcohol use, symptoms of depression or anxiety, and impairments in attention. CONCLUSIONS: Twenty-percent of community-dwelling older adults living in a US state where recreational marijuana use is illegal had a history of marijuana use. Recent marijuana use was less common but, consistent with prior research, associated with other substance use and poorer mental health.

Association of plasma biomarkers of Alzheimer's disease and related disorders with cognition and cognitive decline: The MYHAT population-based study.

INTRODUCTION: Plasma biomarkers of Alzheimer's disease and related dementias predict global cognitive performance and decline over time; it remains unclear how they associate with changes in different dementia syndromes affecting distinct cognitive domains. METHODS: In a prospective study with repeated assessments of a randomly selected population-based cohort (n = 787, median age 73), we evaluated performance and decline in different cognitive domains over up to 8 years in relation to plasma concentrations of amyloid beta 42/40 (Aß42/40) ratio, phosphorylated tau181 (p-tau181), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP). RESULTS: Cross-sectionally, memory showed the strongest associations with p-tau181, and attention, executive, and visuospatial functions with NfL. Longitudinally, memory decline was distinguishable with all biomarker profiles dichotomized according to data-driven cutoffs, most efficiently with Aß42/40. GFAP and Aß42/40 were the best discriminators of decline patterns in language and visuospatial functions, respectively. DISCUSSION: These relatively non-invasive tests may be beneficial for clinical screening after replication in other populations and validation through neuroimaging or cerebrospinal fluid analysis. HIGHLIGHTS: We performed a prospective study with up to 8 years of repeated domain-specific cognitive assessments and baseline plasma Alzheimer's disease and related dementias biomarker measurements in a randomly selected population-based cohort. We considered distinct growth curves of trajectories of different cognitive domains and survival bias induced by missing data by adding quadratic time and applying joint modeling technique. Cross-sectionally, memory showed the strongest associations with plasma phosphorylated tau181, while attention, executive, and visuospatial functions were most strongly associated with neurofilament light chain. Longitudinally, memory and visuospatial declines were most efficiently distinguished by dichotomized amyloid beta 42/40 profile among all plasma biomarkers, while language was by dichotomized glial fibrillary acidic protein. These relatively non-invasive tests may be beneficial for clinical screening; however, they will need replication in other populations and validation through neuroimaging and/or cerebrospinal fluid assessments.

Lifestyle and incident dementia: A COSMIC individual participant data meta­analysis.

INTRODUCTION: The LIfestyle for BRAin Health (LIBRA) index yields a dementia risk score based on modifiable lifestyle factors and is validated in Western samples. We investigated whether the association between LIBRA scores and incident dementia is moderated by geographical location or sociodemographic characteristics. METHODS: We combined data from 21 prospective cohorts across six continents (N = 31,680) and conducted cohort-specific Cox proportional hazard regression analyses in a two-step individual participant data meta-analysis. RESULTS: A one-standard-deviation increase in LIBRA score was associated with a 21% higher risk for dementia. The association was stronger for Asian cohorts compared to European cohorts, and for individuals aged ≤75 years (vs older), though only within the first 5 years of follow-up. No interactions with sex, education, or socioeconomic position were observed. DISCUSSION: Modifiable risk and protective factors appear relevant for dementia risk reduction across diverse geographical and sociodemographic groups. HIGHLIGHTS: A two-step individual participant data meta-analysis was conducted. This was done at a global scale using data from 21 ethno-regionally diverse cohorts. The association between a modifiable dementia risk score and dementia was examined. The association was modified by geographical region and age at baseline. Yet, modifiable dementia risk and protective factors appear relevant in all investigated groups and regions.