Discussion
SECONDARY
In this paper, the methodological design of the Movementss study is described. Furthermore, we explain how quantitative and qualitative data are combined in a mixed-methods approach. To our knowledge, this is the first RCT examining both short- and long-term effects on the effectiveness of an integrated lifestyle intervention program in children with various MI combined with CAU. It is estimated that the data collection will be completed in spring 2024 (We would like to emphasize two unique features and strengths of this study. First, the use of a mixed methods design to validate the quantitative and qualitative data findings. The purpose of pairing qualitative and quantitative components within this study is to better understand this intervention's tailored approach. Qualitative measurements can help to explain and interpret quantitative measurements; for example, the perception of caregivers and children on how they experienced the intervention can give a better insight into the ‘how’ and ‘why’ of its effectiveness. More importantly, it is crucial to explore both patients' and healthcare professionals' expectations and experiences of the intervention before implementing it in clinical practice or developing similar interventions in other settings.Second, this intervention's systematic and tailored approach increases its transferability to clinical practice. From the literature, it is known that interventions will have a better chance of success when setting goals tailored to the needs, interests, and environment of the participants [In addition to the strengths of this study, we are aware of possible pitfalls. As tertiary care children are highly vulnerable, there is a possibility that this intensive intervention will be too demanding for the children and their parents, leading to dropouts. Also, as a result of the specific group of children in our study, we cannot generalize the results to the general population outside of tertiary care (i.e., primary and secondary care). However, if we find any positive effects in this population, it is likely that the intervention is effective in less specialized populations as well.Overall, the awareness that lifestyle factors may be related to MI has grown rapidly, in both children and adolescent populations [