Abstract
BACKGROUND: There is a call for sustainable, evidence-based interventions in schools to promote mental health in schoolchildren. Our primary aim of this trial is to evaluate the effectiveness in vulnerable pupils of a school teacher training programme to teach mindfulness (".b" programme) as a part of compulsory class room teaching in Danish schools on the pupils' self-reported mental health at 6-month follow-up. Our secondary aim is to evaluate the effectiveness of the school teacher training programme to teach the ".b"-programme as a part of compulsory class room teaching among the total pupil population on the pupils' self-reported mental health at 3 and 6 months after baseline. METHODS: The pragmatic cluster two-armed randomised controlled trial includes 110 municipal or private schools from all five regions in Denmark; 191 school teachers and approximately 2000 pupils at 11-15 years of age. Exclusion criteria; for schools: < 100 pupils; for pupils: parental opt out. Our intervention consists of (A) a school teacher training programme and (B) the ".b"-programme delivered as part of compulsory class room teaching in schools to pupils at the age of 11-15 years. The pupils in the control schools receive education as usual. Our primary study population is the vulnerable subgroup with a Strengths and Difficulties Questionnaire (SDQ) total difficulties score > 80% percentile at baseline (approximately 400 pupils). The primary outcome is change in the SDQ total score by the pupils. We also evaluate the effectiveness among the total pupil study population and in girls and boys, respectively and use other measures on mental health. Data will be analysed with repeated measurement models taken clusters into account. DISCUSSION: This large-scale trial will estimate the effectiveness of a population-based strategy on mental health in Danish schoolchildren. The trial evaluates the effect of a school teacher training programme, where teachers are trained in teaching the ".b" programme. The ".b" programme will be taught as a part of compulsory class room teaching. The intervention takes implementation issues into account. Effectiveness will be evaluated both in a vulnerable subgroup and among the total population. Trial registration number ClinicalTrials.gov Identifier: NCT04208113, registered December 23 2019, https://clinicaltrials.gov/ct2/show/NCT04208113 .