Background Schools offer a valuable setting to promote good health and mental well-being amongst young people. Schools are complex systems and as such systems interventions are needed to improve student health and well-being. Despite an increase in the use of systems-based approaches in public health research, there remain limited examples of applying systems thinking to school health promotion interventions. This study aimed to use a systems perspective to evaluate the South West - School Health Research Network to develop a school systems map for England and to understand how the network could contribute to system-wide change.

Methods This is a qualitative process evaluation comprising of 26 semi-structured interviews. Interview participants consisted of school staff (n=11), local authority staff (n=5), and wider key stakeholders (n=10), including policy makers, governors, academics, charity leaders and school-based NHS staff. A 7-stage framework approach was used to analyse the interview data.

Results Three main themes were developed from the framework analysis; 1) Fitting in with the wider landscape (England’s education system as a key challenge for systems based approaches, the need to address changing needs and political interest, the importance of linking in with existing networks, services and intervention providers and reflections on a regional vs. national network); 2) Partnership working (the importance of representation in school, Ofsted: opportunities and challenges and sharing data and practice across systems); 3) Informing policy and allocation of resources (informing policy and guidance and targeted distribution of funding and resource).

Conclusion The findings of this study highlight the vital nature of multi-sector partnership working and intervening and monitoring at multiple levels to improve adolescent health and well-being through a school health research network. The findings also draw attention to the complexity of the current landscape of school health promotion in England and the need to take a systems approach. School health research networks can play a key role in facilitating the needs within the system including collaboration, identifying local need, better targeting of resources, sharing data and best practice across different parts of the system and informing regional and national policy.