A randomized controlled trial in schools aimed at exploring mechanisms of change of a multifaceted implementation strategy for promoting mental health at the workplace

BACKGROUND: This study will explore implementation mechanisms through which a single implementation strategy and a multifaceted implementation strategy operate to affect the implementation outcome, which is fidelity to the Guideline For The Prevention of Mental Ill Health within schools. The guideline gives recommendations on how workplaces can prevent mental ill health among their personnel by managing social and organizational risks factors in the work environment. Schools are chosen as the setting for the study due to the high prevalence of mental ill health among teachers and other personnel working in schools. The study builds on our previous research, in which we compared the effectiveness of the two strategies on fidelity to the guideline. Small improvements in guideline adherence were observed for the majority of the indicators in the multifaceted strategy group. This study will focus on exploring the underlying mechanisms of change through which the implementation strategies may operate to affect the implementation outcome. METHODS: We will conduct a cluster-randomized-controlled trial among public schools (n=55 schools) in Sweden. Schools are randomized (1:1 ratio) to receive a multifaceted strategy (implementation teams, educational meeting, ongoing training, Plan-Do-Study-Act cycles) or a single strategy (implementation teams, educational meeting). The implementation outcome is fidelity to the guideline. Hypothesized mediators originate from the COM-B model. A mixed-method design will be employed, entailing a qualitative study of implementation process embedded within the cluster-randomized controlled trail examining implementation mechanisms. The methods will be used in a complementary manner to get a full understanding of the implementation mechanisms. DISCUSSION: This implementation study will provide valuable knowledge on how implementation strategies work (or fail) to affect implementation outcomes. The knowledge gained will aid the selection of effective implementation strategies that fit specific determinants, which is a priority for the field. Despite recent initiatives to advance the understanding of implementation mechanisms, studies testing these mechanisms are still uncommon. TRIAL REGISTRATION: ClinicalTrials.org dr.nr 2020-01214. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13012-022-01230-7.