Table 1:

List of Engagement strategies

Engagement Strategy	Details
CEDAR Facebook group	A private Facebook group was developed to disseminate knowledge and facilitate dialogue among prospective and existing CEDAR participants Posts include resources and educational materials pertaining to Black brain health
Participant testimonials	3 Community-Science Partnership Board members shared their motivations for joining CEDAR and personal experiences with Alzheimer’s disease Include both written statements posted to the Brain Health Registry website and brief videos shared with CEDAR participants via email and social media
Investigator videos	Two CEDAR investigators recorded videos explaining the study and the importance of including Black adults in research Videos distributed via social media and email
13-week email engagement campaign	Series of 13 emails sent to CEDAR participants to provide educational resources pertaining to Black brain health Emails also share recent news in the Alzheimer’s field
Blog posts	Educational blog posts about brain health are distributed to prospective and existing CEDAR participants via social media channels
Compensation	Compensation for completing study tasks was increased from $25 to $50 partway through the study community board members are compensated $100 per quarterly meeting attended
Landing page	Participants see a culturally tailored landing page when they enroll in CEDAR Landing page contains links to learn more about the study and links to the CEDAR Facebook page
Referrals to other studies	All Black Brain Health Registry participants received an email featuring BHR and collaborator studies Objective was to increase Black representation in studies