A cluster-randomized controlled trial assessing the effectiveness of a multifaceted versus a discrete implementation strategy on fidelity to an occupational guideline for the prevention of mental health problems at the workplace: a dual perspective from Swedish schools.

BACKGROUND: Although the management of psychosocial risks in the work environment represents an evidence-based approach to the prevention of mental health problems, its implementation is limited, including in schools, and knowledge on how to support better implementation is scarce. This study compares the effectiveness of a multifaceted vs. a discrete implementation strategy on fidelity to an occupational guideline for the prevention of mental health problems. Dual perspectives were used to assess fidelity, an important aspect of the measurement agenda. METHODS: A cluster-randomized controlled trial was conducted among 55 schools in Sweden. A multifaceted strategy (educational meeting, implementation teams, ongoing training, Plan-Do-Study-Act cycles, and facilitation) was compared with a discrete strategy (teams participating in the educational meeting). Fidelity to the guideline's recommendations from the recipients' perspective was measured by questionnaire (Baseline n = 2276; 12 months n = 1891). Fidelity from the implementers' perspective (n = 54) was assessed via a checklist at 12 months. Linear mixed modeling was used. A qualitative approach was applied to analyze the open-ended responses to the checklist. RESULTS: Absolute changes in recipient fidelity were observed in all three indicators of the guideline's recommendation 1 (Multifaceted: 13.2 to 19.5%, Discrete: 10.4 to 13.2%). A statistically significant effect was found favoring the multifaceted strategy (d = 0.16). The indicator of recommendation 2 also supported the effect of the multifaceted strategy (Multifaceted: 9.2%, Discrete: 5.0%; d = 0.16). The largest difference between the strategies was observed for recommendation 3, for six indicators (Multifaceted: 0.7 to 13.9%, Discrete:-3.2 to 0.0%; d = 0.19 to 0.41). Convergence was observed between the two perspectives in support of the multifaceted strategy's favorable effect on guideline fidelity compared to the discrete strategy. The findings complemented each other, with implementers describing the activities that were enacted and recipients quantifying the change in fidelity over time. CONCLUSIONS: The multifaceted strategy was more effective than the discrete strategy in fidelity attainment after 12 months. Assessing fidelity from the implementer and recipient perspectives provided an understanding of the contextual functioning of the strategies, highlighting the variation in fidelity and the importance of examining the need for adaptations of strategies during the implementation process. TRIAL REGISTRATION: The trial was registered the 9th of August 2021 at Clinicaltrials.gov with Trial registration number: NCT05019937 .