Conclusions
RECRUITMENT
The purpose of this study was to understand who volunteers to participate in a digital health study because of an exclusive and large-scale remote email recruitment campaign. Contrary to other mass media campaign evaluations, our study was able to characterize the sample of patients who did and did not enroll, whereas previous evaluations had limited to no information about the latter group. Overall, the findings showed that enrollment was driven more strongly by sociodemographic than clinical factors. Email is also an extremely efficient means of recruiting participants from a large list into the Health eHeart Study. Despite some improvements in representation, the formulation of truly diverse studies will require additional resources and strategies to overcome remaining participation barriers.The Health eHeart Study has received funding from the Salesforce Foundation, the Patient-Centered Outcomes Research Institute (PPRN-1306-04709), and the University of California, San Francisco (UCSF), Cardiology Division. We acknowledge the UCSF Clinical & Translational Science Institute and Health eHeart team for data extraction guidance and support. Generative artificial intelligence was not used in any portion of the manuscript writing.Authors' Contributions: MYN, MJP, and CRL conceptualized the study, MJP and CRL provided guidance and oversight; MYN carried out the analyses and wrote the initial draft, and all authors reviewed and critically revised the final manuscript.Conflicts of Interest: None declared.Health eHeart Study recruitment email delivered to eligible UCSF patients.Email campaign details for initial wave and follow-up wave.Unadjusted odds of registration among contacted patients (left) and consent among registered patients (right).