Introduction This study aimed to identify the relationship of sociodemographic variables with older adults participation in an online registry for recruitment and longitudinal assessment in cognitive aging. Methods Using Brain Health Registry (BHR) data, associations between sociodemographic variables (sex, race, ethnicity, education) and registry participation outcomes (task completion, willingness to participate in future studies, referral/enrollment in other studies) were examined in adults aged 55+ (N = 35,919) using logistic regression. All models included sex, race, ethnicity, education, age, and subjective memory concern. Results Non‐white race, being Latino, and lower educational attainment were associated with decreased task completion and enrollment in additional studies. Results for sex were mixed. Discussion The findings provide novel information about engagement in online aging‐related registries, and highlight a need to develop improved engagement strategies targeting underrepresented sociodemographic groups. Increasing registry diversity will allow researchers to refer more representative populations to Alzheimer's and related dementias prevention and treatment trials.

BackgroundRemote, internet‐based methods for recruitment, screening, and longitudinally assessing older adults have the potential to greatly facilitate Alzheimer’s disease and related research, including clinical trials and observational studies.MethodsThe Brain Health Registry (BHR) is an online website and registry that includes a comprehensive battery of self‐ and study partner‐report questionnaires and online neuropsychological tests. Participants are asked to return at 6‐month intervals for longitudinal follow‐up. Recently, new online infrastructure for managing remote biomarker (saliva, blood) collection and for linking in‐clinic and online data were added. Multiple current initiatives aim to increase recruitment and engagement of underrepresented populations using digital, community engaged research strategies to improve generalizability of results. These include the recent launch of a Spanish‐language website, and projects focused on increasing enrollment and task completion of Black/African American and Hispanic/Latinx individuals.ResultsBHR includes >95,000 participants, >9000 of whom have enrolled study partners, 40% return for longitudinal follow up, 64% are age 55+, 80% are female, 80% identify as Non‐Latinx White, and 10% identify as Hispanic/Latinx. Participants have an average of 16.2 years of education. BHR has made >86,000 referrals to other studies, resulting in >5000 BHR participants enrolled in 25 different aging and AD observational studies and treatment trials. Over 2400 participants are co‐enrolled in BHR and collaborator studies, with online data linked to in‐clinic data. 573 participants have undergone APOE genotyping using remote saliva collection, and 629 have had blood collected using local phlebotomy for AD plasma biomarker analysis. Accumulating evidence supports the feasibility and validity of the approach, including associations with in‐clinic assessments, the ability to accurately detect MCI and enrichment for amyloid positivity.ConclusionsMajor advantages of the BHR approach are scalability and accessibility. Challenges include compliance, retention, and cohort diversity. Lessons learned from BHR, and components of the existing infrastructure, can be used to inform future remote clinical trial design. One such future effort is ADNI4. To facilitate enrollment of new participants, ADNI4 will establish an online recruitment and screening portal, with a remote phlebotomy component, to efficiently identify those from underrepresented populations, and those likely to have preclinical and prodromal AD.

Introduction This culturally tailored enrollment effort aims to determine the feasibility of enrolling 5000 older Latino adults from California into the Brain Health Registries (BHR) over 2.25 years. Methods This paper describes (1) the development and deployment of culturally tailored BHR websites and digital ads, in collaboration with a Latino community science partnership board and a marketing company; (2) an interim feasibility analysis of the enrollment efforts and numbers, and participant characteristics (primary aim); as well as (3) an exploration of module completion and a preliminary efficacy evaluation of the culturally tailored digital efforts compared to BHR's standard non–culturally tailored efforts (secondary aim). Results In 12.5 months, 3603 older Latino adults were enrolled (71% of the total California Latino BHR initiative enrollment goal). Completion of all BHR modules was low (6%). Discussion Targeted ad placement, culturally tailored enrollment messaging, and culturally tailored BHR websites increased enrollment of Latino participants in BHR, but did not translate to increased module completion. Highlights Culturally tailored social marketing and website improvements were implemented. The efforts enrolled 5662 Latino individuals in 12.5 months. The number of Latino Brain Health Registry (BHR) participants increased by 122.7%. We failed to adequately enroll female Latinos and Latinos with lower education. Future work will evaluate effects of a newly released Spanish‐language BHR website.