Feasibility and pilot study protocol of the SURE programme: a co-designed whole-school approach intervention to promote migrant-background adolescents wellbeing in secondary education

BACKGROUND: Adolescents with a migrant background may be at greater risk of experiencing poor mental health and psychosocial wellbeing. Whole-school approach (WSA) interventions with strong stakeholder commitment are considered to be a promising avenue for improving this population's wellbeing. Using such an approach, the co-designed universal SURE intervention aims to nurture a positive school climate and provide social support for migrant-background adolescents in Madrid, Spain, with the wider objective of bolstering adolescent wellbeing. METHODS: Conducted in two medium-sized secondary schools in Getafe (Madrid), this research comprises two distinct components. First, a feasibility study utilises a pragmatic mixed-methods design to assess the implementation process and acceptability of the SURE intervention among students, staff, families, and community stakeholders. Second, an exploratory pilot study employs a quasi-experimental, non-equivalent control group design to estimate parameters for a future trial. During the 2025-2026 academic year, the intervention school will receive the SURE programme, while the comparison school follows the standard curriculum. Quantitative outcome data will be collected via self-report from students in 2° and 3° ESO (aged 13-15). Primary feasibility outcomes include recruitment and retention rates, intervention fidelity, and acceptability; secondary outcomes will be used to descriptively explore clinical mental health indicators (emotional symptoms, conduct problems, positive affect, and life satisfaction), alongside educational engagement and school participation. DISCUSSION: This pilot and feasibility study aims to determine whether the SURE intervention procedures are acceptable and viable within the secondary education context. Findings will allow the research team to refine the intervention protocols, underlying mechanisms, and outcome measures. This process is essential to ensure the precision of estimates and the robustness of the research techniques before the SURE programme is scaled up and evaluated in a larger, definitive cluster randomised controlled trial. TRIAL REGISTRATION: The trial was registered on the Open Science Framework (OSF) (Identifier: https://doi.org/10.17605/OSF.IO/XQ52T) before the enrolment of the first participant.