Background: We have recently completed a project which involved two linked systematic reviews evaluating the effectiveness and experiences of mental health interventions for children and young people with long-term physical conditions.

Objectives:To draw together the findings from two linked systematic reviews of quantitative and qualitative evidence in an overarching synthesis, and describe and reflect on the approach used.

Methods: We used a deductive question and answer approach in which questions based on the findings of each review were generated and used to interrogate the other review for information that could potentially inform the findings or explain gaps in the literature. The process was conducted whilst findings from both reviews were preliminary to allow for the issues raised to also contribute to the synthesis of the individual reviews. Questions were related to either the synthesised review findings or descriptive details regarding included studies.

Results:Nine categories of finding emerged from the analysis – i) the degree of overlap between reviews, ii) availability of up to date, good quality research, iii) what works for whom? iv) adapting interventions, v) accessibility and delivery, vi) stress and coping, vii) working with family or peers, viii) therapeutic relationships and, ix) holistic approach. The findings were presented narratively. Descriptions of the categories, the contribution of each systematic review to the categories and the implications of each category for practice and future research were tabulated.

Conclusions: Despite differences in research questions, methods of synthesis and types of interventions in the two systematic reviews, the novel methods used in this overarching synthesis generated new findings or strengthened evidence. This overarching synthesis led to a number of tentative implications for policy, practice and future research.