Assessing Equitable Inclusion of Underrepresented Older Adults in Alzheimer's Disease, Related Cognitive Disorders, and Aging-Related Research: A Scoping Review

Background and Objectives: The rapidly aging and diversifying U.S. population is challenged by increases in prevalence of Alzheimer's disease (AD) and aging-related disorders. We conducted a scoping review to assess equitable inclusion of diverse older adult populations in aging research focused on National Institutes of Health (NIH)-sponsored research. Research Design and Methods: The scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol. The search was limited to NIH-funded studies focusing on aging, AD, and Alzheimer's disease-related dementias (ADRD) and included adults aged 55 and older. The priority populations and health disparities put forth by the National Institute on Aging Health Disparities Framework serve as a model for guiding inclusion criteria and for interpreting the representation of these underrepresented groups, including racial-ethnic minorities, socioeconomically disadvantaged, rural populations, groups with disabilities, and lesbian, gay, bisexual, transgender, and queer or questioning (LGBTQ) communities. Results: Our search identified 1,177 records, of which 436 articles were included in the analysis. Inclusion of individuals with ADRD and mild cognitive impairment, racial-ethnic minorities, rural populations, socioeconomically disadvantaged, groups with disabilities, and LGBTQ communities were poorly specified in most studies. Studies used multiple recruitment methods, conducting studies in community settings (59%) and hospitals/clinics (38%) most frequently. Incentives, convenience factors, and sustained engagement via community-based and care partners were identified as key strategies for improved retention. Discussion and Implications: This scoping review identified gaps in existing literature and aims for future work, including stronger research focus on, better inclusion of, and improved data collection and reporting of older adults from underrepresented groups.