The effectiveness of implementing the Guideline for the Prevention of Mental Ill-health Problems at the Workplace on health-outcomes, organizational and social risk factors: a cluster-randomized controlled trial in Swedish schools.

Objectives: This study aimed to compare the effectiveness of the multifaceted implementation strategy (multifaceted group) versus a discrete implementation strategy (discrete group) for implementing the Swedish Guideline for the Prevention of Mental Ill-health Problems at the Workplace on the primary intervention outcome - exhaustion - and secondary outcomes of stress, health, recovery, psychosocial safety climate, and social and organizational risk factors. Another aim was to examine whether the primary and secondary outcomes differed on the basis of guideline adherence levels, irrespective of the group.

Methods: A cluster-randomized waiting-list controlled trial with 6- and 12-months follow-up was conducted among 19 Swedish public schools. Primary and secondary outcomes as well as guideline adherence were assessed by self-reported questionnaire. Linear mixed modeling was used to compare differences in outcomes between the groups from baseline to 6 and 12 months, and in relation to different adherence levels.

Results: The trial comprised 698 employees (83.1%) participated. There were no differences between groups in the primary and secondary outcomes at 6 months, while at 12 months differences were observed for some outcomes to the advantage of the discrete group. Better guideline adherence was associated with improvements in exhaustion at 12 months and the secondary outcomes of psychosocial safety climate, work organization and job content, interpersonal relations and leadership, and recovery over 6 and 12 months.

Conclusion: The multifaceted implementation strategy was no more effective than the discrete strategy in improving health outcomes or organizational and social work environment. However, higher adherence to the guideline was associated with larger improvements in health outcomes and organizational and social work environment, irrespective of the implementation strategy used.