Evaluating Mechanisms and Implementation of an HPS Intervention in Danish 10th Grade

Health Promoting School (HPS) interventions can improve adolescent mental health and well-being, however, implementation in real-world school systems remains challenging. This study evaluates the implementation and mechanisms of “My Life – I Decide” – a HPS intervention delivered by health consultants targeting 10th-grade students (age 15-17) in Denmark. A realist-informed, multi-method process evaluation was conducted across four intervention schools (11 classes). Data (May 2025 to June 2026) included post-session surveys with health consultants (n=224), classroom observations (n=23), student focus group (n=4), interviews with teachers (n=4), health consultants (n=8), and school and municipal managers (n=8). Implementation outcomes (fidelity and acceptability) were assessed and mechanisms at student and system levels were analyzed. Preliminary findings showed high fidelity in the teaching phase and inconsistency in planning and anchoring phases with limited evidence of developing HPS actions to initiate school-level changes. At student level, curriculum engagement was shaped by peer norms, school fatigue, and classroom positioning, where participating openly was socially risky. Engagement was observed in situations where activities were concrete, practice-based and socially legitimate, positively affecting student and class well-being. At the system level, shared pedagogical approaches and alignment between teachers, school managers and health consultants supported cross-sectoral collaboration and implementation, whereas perceived rigidity of teaching materials and low prioritization of implementing changes beyond the curriculum constrained system-level change. Implementation depended on alignment between classroom social dynamics, flexibility in delivery, pedagogical approaches, and school organizational readiness. Strengthening the integration and prioritization of HPS elements may be critical for supporting school-level change in similar interventions.

Key messages

• Student engagement is shaped by social norms; reducing social risk and increasing relevance is key to participation.

• Limited prioritization of HPS elements constrained school-level change, highlighting the need for stronger school organizational support.