Recruitment and Screening Methods in Alzheimer's Disease Research: The FIT-AD Trial

Recruiting older adults with Alzheimer's disease (AD) dementia into clinical trials is challenging requiring multiple approaches. We describe recruitment and screening processes and results from the Functional Improvement from Aerobic Training in Alzheimer's Disease study (FIT-AD Trial), a single-site, pilot randomized controlled trial testing the effects of a 6-month aerobic exercise intervention on cognition and hippocampal volume in community-dwelling older adults with mild-to-moderate AD dementia.

Ten recruitment strategies and a 4-step screening process were used to ensure a homogenous sample and exercise safety. The initial target sample was 90 participants over 48 months which was increased to 96 to allow those in the screening process to enroll if qualified. A tertiary analysis of recruitment and screening rates, recruitment yields and costs, and demographic characteristics of participants was conducted.

During the 48-month recruiting period, 396 potential participants responded to recruitment efforts, 301 individuals were reached and 103 were tentatively qualified. Of these, 67 (69.8%) participants completed the optional magnetic resonance imaging and 7 were excluded due to abnormal magnetic resonance imaging findings. As a result, we enrolled 96 participants with a 2.92 screen ratio, 2.14 recruitment rate, and 31.9% recruitment yield. Referrals (28.1%) and Alzheimer's Association events/services (21.9%) yielded over 49% of the enrolled participants. Total recruitment cost was $38 246 or $398 per randomized participant.

A multiprong approach involving extensive community outreach was essential in recruiting older adults with AD dementia into a single-site trial. For every randomized participant, 3 individuals needed to be screened. Referrals were the most cost-effective recruitment strategy. Clinical Trials Registration Number: NCT0194550.