MEST : A School- Based Health Literacy Intervention Trial

The purpose of this study is to evaluate the effectiveness of the MEST work strategy in upper secondary schools. MEST is a school based, health promoting intervention delivered by school health services and designed to strengthen students' health literacy and mental well being. The study assesses whether implementation of the MEST work strategy results in improved health literacy and mental well being compared with usual school health services. This study is a pragmatic matched-pair cluster-randomized, parallel-group superiority trial in which upper secondary schools are assigned either to an intervention group implementing the MEST work strategy or to a control group continuing with school health services as usual. Student-reported outcomes are collected using digitally administered questionnaires during school hours at baseline (T0), and at 4-month (T1) and 9-month (T2) follow-up assessments following intervention initiation. Baseline data collection was conducted between August and October 2026.

Inclusion Criteria: * Students 16-24 years * Enrolled in participating upper secondary schools * Able to provide informed consent Exclusion Criteria: * Not aged 16-24 years * Not enrolled in participating upper secondary schools * Did not provide informed consent