The roads towards fidelity: a mixed-method study of mechanisms of a multifaceted implementation strategy to improve implementation of a guideline for the prevention of mental Ill-health at the workplace in a school setting

Background Many implementation studies focus on assessing the effectiveness of implementation strategies without investigating the mechanisms explaining their effects. This study investigates the specific mechanisms through which a multifaceted implementation strategy is hypothesized to improve guideline fidelity. This is done by tracing the specific mechanisms through which each discrete strategy achieved proximal outcomes that precede guideline fidelity. Methods Process tracing with comparative case studies was used to analyze qualitative data from a subsample of 16 implementers participating in a cluster-randomized controlled trial exploring the mechanisms by which a multifaceted strategy affects fidelity to a guideline for prevention of mental problems in schools. The study involved four steps: (1) Organizing a traceable process theory of change; (2) Gathering data to validate, modify, or expand the theory; (3) Coding data through qualitative content analysis; and (4) Causal analysis to articulate the theory’s mechanisms, including temporal order and key contextual conditions that explain success or failure. The unit of analysis was implementers who were members of the schools’ implementation teams, with each implementer representing a case. Results The analyses illuminated distinct pathways that explain how each of the five discrete strategies led to implementation success. (1) Organizing Implementation Teams enabled participation in implementation activities, as principals created an environment with dedicated resources, enabling social influences; (2) Educational meetings influenced the decision to implement the guideline through the educators’ who promoted knowledge acquisition among the implementers and shaped their beliefs about the implementation; (3) Ongoing Training influenced the intention for implementation and enactment of activities through educators’ engaged processes around ongoing acquisition and refinement of skills, which gradually built belief in implementation capability; (4) Small Cyclical Tests of Change influenced behavioral regulation as the workshops engaged repeated engagement in goal setting, action planning, reflection, and adjustment; (5) Facilitation supported implementers’ goal setting and prioritization by creating an environmental context, enabling implementers’ social influence through receiving social support from facilitators. Unsuccessful pathways for each strategy were also identified and explained. Conclusions This study traced the specific sequences of actions and interactions through which five discrete implementation strategies contributed to guideline implementation. The findings illustrate how the mechanisms of the multifaceted strategy can be successfully engaged and why they may fail under certain conditions. Trial registration The trial was registered the 9th of August 2021 at Clinicaltrials.gov with Trial registration number: NCT05019937