Terminology and Classification of Online Clinical Trials: A Scoping Review Protocol

This scoping review will systematically map and synthesise how online clinical trials are labelled, defined, and categorised across all health conditions. The rapid expansion of digital technologies has enabled clinical trials to move beyond traditional site-based models, leading to increasing use of terms such as “online”, “virtual”, “digital”, “remote”, “internet-based”, “web-based”, and “decentralised clinical trial (DCT)”. However, these terms are often used inconsistently and without explicit definition. This lack of conceptual clarity limits comparability across studies, complicates evidence synthesis, and creates ambiguity regarding which trial components (e.g., recruitment, consent, intervention delivery, follow-up) are delivered digitally versus in-person . The primary aim of this review is to systematically map terminology, definitions, and classification approaches used to describe online clinical trials. Using established scoping review methodology (Arksey & O’Malley; Levac et al.; JBI guidance) and reported in accordance with PRISMA-ScR, the review will identify and compare terminology across academic publications, methodological literature, regulatory guidance, and organisational sources . Eligibility criteria are structured using the Population-Concept-Context (PCC) framework, with a focus on sources describing human clinical trials or providing methodological/regulatory definitions of online or digitally enabled trial designs . Searches will be conducted in MEDLINE (via OVID), Embase, Web of Science Core Collection, and Cochrane CENTRAL, supplemented by targeted journal and regulatory website searches . A purposive sampling strategy (approximately 40-60 studies) will be used to ensure diversity across health conditions and modes of digital implementation . Data charting will extract terminology used, whether explicit definitions are provided, verbatim definitional text, associated trial design features, and any proposed classification frameworks . Findings will be synthesised descriptively, comparing definitions across sectors and mapping relationships between terminology and trial design components. Expected outcomes include: • A comprehensive map of terminology used to describe online clinical trials, • Side-by-side comparison of explicit definitions, • Identification of areas of conceptual convergence and divergence, • Development of a defensible classification scheme and standardised working definitions for online clinical trial designs. This review addresses a clear gap in the literature by providing the first dedicated, concept-focused synthesis of terminology and classification in online clinical trials . The findings will inform subsequent phases of the doctoral research, including development of a structured framework for feasibility assessment of online clinical trials.