Key Insights into Developing Qualitative Concept Elicitation Work for Outcome Measures with Children and Young People.

Qualitative concept elicitation can develop meaningful patient-reported outcome measures for children and young people; however, the methods used for concept elicitation are often underreported for this population. This paper provides in-depth insight into the methods used for concept elicitation with children and young people, with a focus on key stages of concept elicitation that are challenging or unique to doing this research with children. Drawing on our experiences of developing wellbeing measures for children and young people aged 6-15 years, we detail the processes followed in our qualitative concept elicitation work, covering issues related to sampling and recruitment, encouraging informed assent and freedom over children and young people's involvement in concept elicitation, and the use of creative and participatory methods to develop measure items. We provide reflections on the approaches taken to navigate challenging aspects of concept elicitation with children and young people. Our reflections suggest that using existing links and online recruitment methods can help to navigate organisational gatekeepers, and using appropriate processes to develop study information and obtain informed assent can ensure that research is inclusive and that children have the freedom to decide whether to be involved. Our adaptation of a creative and participatory activity to generate concepts for measure items suggests that such approaches can be engaging and may help to give children greater control over their participation. In detailing our methods, we hope to have developed a useful resource for other researchers, while highlighting the value of transparent reporting in this area.