Selecting and Preparing Clinical Sites for the Successful Conduct of Decentralized Clinical Trial Activities–Findings From the Trials@Home <scp>RADIAL</scp> Proof‐of‐Concept Trial

Decentralized clinical trials (DCTs) offer opportunities to improve trial accessibility, participant convenience, and efficiency, yet may pose significant operational challenges for clinical trial sites. This paper presents the operational insights gained from selecting, training, and supporting clinical sites within the RADIAL proof-of-concept trial, part of the Trials@Home project. RADIAL was a multicenter, low-intervention phase IV trial comparing conventional, hybrid, and fully decentralized approaches for individuals with type 2 diabetes mellitus across six European countries. Site selection involved detailed feasibility assessments evaluating operational capabilities, recruitment potential, technological readiness, and willingness to implement decentralized elements. Despite proactive training, including ongoing support via a centralized helpdesk, sites faced initial difficulties with technology management and participant onboarding. Contractual complexities were prominent, particularly regarding clearly delineating responsibilities and data handling in agreements involving third-party providers. Moreover, integrating third-party services necessitated meticulous oversight strategies and continuous stakeholder coordination to ensure regulatory compliance and efficient trial management. Our experiences underscore essential considerations for future DCT implementations: proactive stakeholder alignment; tailored, timely, and ongoing training and support; intuitive technology design informed by clinical user input; robust, centralized oversight structures; and clearly defined delegation frameworks for third-party engagements. Addressing these operational considerations will facilitate smoother transitions toward decentralized clinical research models, maximizing their potential benefits while managing associated complexities effectively-especially for clinical site staff.