Optimizing recruitment strategies for healthy older adults in prevention clinical trials: A scoping review

Older adults aged 75 and older (75+) represent the fastest-growing demographic in the USA yet remain underrepresented in prevention-focused clinical research. This scoping review evaluated recruitment strategies used in healthy aging clinical trials targeting this population, with particular attention to technology-enabled and belonging-focused approaches. A PubMed search initially identified only four US-based studies focused on adults aged 75+. To broaden the scope and enrich the analysis, additional studies involving adults aged 65+ and those with pre-existing conditions were included, yielding a total of 23 relevant studies. Recruitment strategies were analyzed using the Design for Belonging framework to assess how inclusion and engagement were fostered. Findings revealed that adults aged 75+ preferred traditional methods - targeted mailings, phone calls, and in-person outreach - due to barriers related to digital access and usability. In contrast, adults aged 65+ showed greater receptivity to digital tools such as electronic health records, social media, and web-based enrollment. Community engagement and culturally tailored materials are effective across all age groups. However, few studies addressed later-stage engagement strategies like advocacy and trust repair. These results underscore the importance of tailoring recruitment strategies to aging subgroups, combining personalized outreach with inclusive design to enhance equity and retention in clinical research.