Development of a core screening, assessment and outcome set for cancer prehabilitation: an international Delphi consensus study protocol

INTRODUCTION: A core screening, assessment and outcome set is needed in cancer prehabilitation to standardise what is measured in both research and services. Currently, there is significant variation in measures used, which limits comparability between studies and evidence synthesis. Standardising measures will improve the quality, comparability and impact of research by reducing heterogeneity between studies, minimising reporting bias, improving trial efficiency, enabling data synthesis into large datasets, supporting international collaboration and data sharing, and accelerating the implementation of best practices. METHODS AND ANALYSIS: An international Delphi consensus process will be conducted involving patients, healthcare professionals and researchers to identify screening, assessment and outcomes and their corresponding measurement instruments, to be included in a core set. The study consists of three phases: (1) A scoping review to identify screening, assessment and outcomes and associated measurement instruments currently used in cancer prehabilitation. (2) At least two rounds of a modified Delphi survey to prioritise the identified screening, assessment and outcomes using a 1-9 Likert scale. Consensus will be defined across stakeholder groups using prespecified thresholds. A consensus meeting will be held if agreement is not reached. (3) Measurement instruments corresponding to each retained screening, assessment and outcome will be assessed for quality for measurement properties and feasibility. Further Delphi rounds will be conducted to reach consensus on the most appropriate measurement instrument for each core screening, assessment and outcome. ETHICS AND DISSEMINATION: The study has ethical approval (Ref: 25/NW/0159). Findings will be disseminated through peer-reviewed publications, conference presentations, stakeholder networks and made publicly available via the Core Outcome Measures in Effectiveness Trials database.