Assessing patient-reported outcomes (PROs) in paediatric oncology research: Which PRO would a pro pick, if a pro was picking PROs?

<h2>Abstract</h2> Patient-reported outcomes (PROs) enable the report of experiences that are only known to the patient, such as how an individual's symptoms, functioning, and quality of life are impacted by a health condition or treatment. The choice of PRO depends on the intended application and associated research questions, and structuring a rationale for the use of PRO data is key to deciding upon a PRO strategy. Rates of PRO use in paediatric oncology research remain low though the general use of PROs in clinical trials has been gradually increasing. This is likely to have risen due to increased emphasis by regulatory agencies to capture outcomes meaningful to patients. Despite increasing interest in PROs, a range of barriers to their use have been identified by researchers exploring their implementation and a pattern of under-reporting of PRO data has also been observed in general oncology trials. Research with children entails specific challenges, including the need for developmentally-appropriate outcome measures, the complexities of family involvement, and the adaptations required in research procedures and settings to accommodate children's physical, cognitive, and emotional development. With the nascent use of PROs in paediatric oncology, there are opportunities to benefit from learning from trials involving adult participants. The current paper outlines considerations for PRO selection for use in paediatric oncology research, describing five steps to determine the PRO study goals, the study outcomes, the reporter(s), measures, and study implementation. We discuss the breadth of applications of PROs in paediatric oncology research and potential for further learning and harmonisation with the aim of centering children's experiences.