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.