Evaluating evidence-based recruitment strategies for Alzheimer’s disease and related dementias clinical trial research: A literature review

• Identifies recruitment challenges limiting efficient and representative ADRD trials. • Summarizes quantitative evidence on effective and ineffective ADRD recruitment strategies. • Finds that multipronged recruitment approaches show promise. • Reveals limited evidence and lack of standardization for scalable recruitment. • Emphasizes routine, transparent reporting to advance science of ADRD recruitment. With the prevalence of Alzheimer’s disease and related dementias (ADRD) rising, prevention and treatment clinical trials are increasingly important. Yet inadequate participant recruitment to ADRD research—a leading cause of trial delays, suspensions, or discontinuations—continues to hinder innovation and increase costs. This literature review aimed to identify ADRD recruitment strategies that are effective and ineffective, based on quantitative outcomes, with the goal of optimizing recruitment and advancing recruitment science. PubMed, Google Scholar, relevant ADRD websites, and references were searched for studies meeting inclusion criteria—those reporting quantitative outcomes aimed at improving recruitment rates, timely recruitment, or representation. Reference lists from relevant systematic reviews and meta-analyses, including publications from leading researchers, were also examined. The Mixed Methods Appraisal Tool (MMAT) was used to assess evidence quality. The search yielded 965 publications, of which 50 met inclusion criteria. Few studies reported recruitment methods for pharmacological trials, and many lacked sufficient detail or standardized reporting to assess quality using MMAT criteria, making it difficult to determine effectiveness. Recruitment efforts deemed successful by study authors often relied on multi-pronged approaches integrating community engagement, structured outreach, and digital tools. However, evidence for effective and scalable strategies remains limited. Advancing ADRD recruitment science requires progress in two key areas: embedding recruitment evaluation directly into trial protocols and encouraging broader sharing of recruitment data. Routine practices, such as publishing recruitment outcomes and adopting standardized reporting, can help close the evidence gap. These approaches enable comparison, replication, and generalizability of effective strategies, ultimately accelerating progress in ADRD research.