Feasibility and lessons learned on remote trial implementation from TestBoston, a fully remote, longitudinal, large-scale COVID-19 surveillance study

Importance: Remote clinical trials may reduce barriers to research engagement resulting in more representative samples. A critical evaluation of this approach is imperative to optimize this paradigm shift in research. Objective: To assess design and implementation factors required to maximize enrollment and retention in a fully remote, longitudinal COVID-19 testing study. Design: Fully remote longitudinal study launched in October 2020 and ongoing; Study data reported through July 2021. Setting: Brigham and Women's Hospital, Boston MA Participants: Adults, 18 years or older, within 45 miles of Boston, MA. Intervention: Monthly and "on-demand" at-home SARS-CoV-2 RT-PCR and antibody testing using nasal swab and dried blood spot self-collection kits and electronic surveys to assess symptoms and risk factors for COVID-19. Main Outcomes: Enrollment, retention, and lessons learned. Results: Between October 2020 and January 2021, we enrolled 10,289 participants reflective of Massachusetts census data. Mean age was 47 years (range 18-93), 5855 (56.9%) were assigned female sex at birth, 7181(69.8%) reported being White non-Hispanic, 952 (9.3%) Hispanic/Latinx, 925 (9.0%) Black, 889 (8.6%) Asian, and 342 (3.3%) other and/or more than one race. Lower initial enrollment among Black and Hispanic/Latinx individuals required an adaptive approach, leveraging connections to the medical system, coupled with community partnerships to ensure a representative cohort. Longitudinal retention was higher among participants who were White non-Hispanic, older, working remotely, and with lower socioeconomic vulnerability. Considerable infrastructure, including a dedicated participant support team and robust technology platforms was required to reduce barriers to enrollment, promote retention, ensure scientific rigor, improve data quality, and enable an adaptive study design to increase real-world accessibility. Conclusions: The decentralization of clinical trials through remote models offers tremendous potential to engage representative cohorts, scale biomedical research, and promote accessibility by reducing barriers common in traditional trial design. Our model highlights the critical role that hospital-community partnerships play in remote recruitment, and the work still needed to ensure representative enrollment. Barriers and burdens within remote trials may be experienced disproportionately across demographic groups. To maximize engagement and retention, researchers should prioritize intensive participant support, investment in technologic infrastructure and an adaptive approach to maximize engagement and retention.