Mapping outcomes in randomised radiology trials: Protocol for a scoping review

This scoping review aims to systematically map how outcomes are defined and operationalised in contemporary radiological randomised clinical trials (RCTs). The findings will inform a subsequent Delphi process to develop a core outcome set for clinical studies in radiology, including adaptive platform trials (APTs), conventional RCTs, and observational studies.

The scoping review will be conducted in accordance with PRISMA-P and PRISMA-ScR guidelines and will encompass articles published from 1 January 2023 in select high-impact general medical and radiological journals, using a search strategy developed and vetted by an independent information specialist. The search strategy yielded 4,202 hits on 7 April 2026. All steps, from screening through data extraction, will be done in duplicate by two independent authors. Extracted trial data will include number of trial sites, number of participants, sub-speciality, intervention type, and interventions under study. For each outcome in each trial, we will extract the name and type of the outcome, operationalisation/definition/tool used, assessment of temporality (e.g. truncation, censoring, repeated sampling), missingness proportion, missingness handling, effect quantification, and statistical analyses of effects (e.g. unadjusted or regression-model based). Data extraction will start with a 10-trial pilot phase for maximised data quality. Data synthesis will be descriptive without risk of bias evaluation.

This scoping review will map how outcomes are defined and operationalised in contemporary radiological RCTs and inform a Delphi process to identify core outcomes for APTs and RCTs, supporting the advancement of value-based radiology.