Effects of the elements in SchoolHealth on adolescents’ health literacy, general self-efficacy and health-related quality of life—A randomized factorial trial

Background: Schools and school health services have a central role in improving adolescent health and quality of life. The national guideline for the Norwegian school health service recommends that school nurses conduct individual health-promoting consultations with eighth graders and collaborate closely with schools to promote healthy life skills and wellbeing. Because professionals expressed a need for practical tools to support this work, the tool SchoolHealth was co-created with school nurses, students, school staff, and other stakeholders. SchoolHealth comprises three key implementation and dissemination elements: Digital feedback and administration tool, Dialog support, and Collaboration materials. The current study evaluates main and interaction effects of these elements on the students’ outcomes health literacy, self-efficacy, and health-related quality of life. It also explores potential sex differences. Methods: SchoolHealth was evaluated in the GuideMe study, a hybrid type 2 factorial cluster-randomized trial. Data was gathered from 1,425 eighth graders (69% of those invited) in 19 Norwegian municipalities. The 48 schools and their assigned school nurses (n=56) were randomized to eight different element combinations. Outcomes were measured with HLSAC, GSE-5 and KIDSCREEN27. Linear mixed-effects models were employed to investigate possible main and interaction effects of the elements in SchoolHealth. Results: Regardless of the elements tested, improvements were observed over the school year in health literacy, general self-efficacy and KIDSCREEN subscores Physical well-being, Autonomy and parent relations, and among girls, in School environment. Health literacy peaked immediately after the consultations, and among girls self-efficacy also peaked. The significant main effects found for the elements Dialog support and Collaboration materials were limited to Autonomy and parent relations. No significant main effects were observed for Digital feedback and administration tool, or for any interactions of elements. No significant sex differences were found in main effects. Conclusions: All students showed improvement in all dimensions at the end of the school year, independent of SchoolHealth elements tested. Since main effects of the elements were limited, a broader evaluation is recommended in an optimized version. The observed short-term effect of health-promoting consultations and the role of interdisciplinary collaboration in schools, in supporting adolescent health and well-being, should be further explored. Clinical trial number: not applicable. Trial registration: ISRCTN reg.nr. 24173836.