Guideline evaluation and implementation mechanisms in school health services (GuideMe): protocol for a hybrid randomized factorial trial

BACKGROUND: Norwegian school health services received a national best-practice guideline in 2017. To promote healthy life skills and identify adolescents needing support, the guideline includes strong recommendations for individual consultations with all 8th graders and increased collaboration with schools. To help implement the recommendations, a blended implementation strategy (SchoolHealth) was co-created with school nurses, students, and stakeholders. SchoolHealth consists of three implementation elements: Digital dialog and administration tool (audit and feedback +), Dialog support (external consultation), and Collaboration materials (targeted dissemination). This hybrid study will test the main and combined effects of the elements on guideline fidelity and effectiveness. METHODS: The GuideMe study is a factorial cluster randomized controlled trial examining SchoolHealth's effectiveness on guideline fidelity and guideline effectiveness goals. Forty Norwegian secondary schools will be randomized to eight different combinations of the elements in SchoolHealth. Participants will include school nurses and school personnel from these schools, and 8(th) grade students (n = 1200). Primary outcomes are school nurses' fidelity to the guidelines and student's ability to cope with their life (i.e., health literacy, positive health behaviors and self-efficacy). Quantitative methods will be used to test effects and mechanisms, while mixed- and qualitative methods will be used to explore mechanisms, experiences, and other phenomena in depth. Participants will complete digital questionnaires at the start and end of the schoolyear, and after the consultation during the schoolyear. The study will run in two waves, each lasting for one school year. The multifactorial design allows testing of interactions and main effects due to equal distribution of all factors within each main effect. Sustainment and scale-up of optimized SchoolHealth elements using national infrastructure are simultaneously prepared. DISCUSSION: The study will investigate possible effects of the implementation elements in isolation and in combination, and hypothesized implementation mechanisms. In-depth study of user experiences will inform improvements to elements in SchoolHealth. The results will yield causal knowledge about implementation strategies and the mechanisms through which they assert effects. Mixed-methods will provide insights into how and when the elements work. Optimizing guideline implementation elements can support adolescents in a crucial life phase. TRAIL REGISTRATION: ISRCTN24173836. Registration date 8 August 2022. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-023-10179-2.