Building Psychological Safety to Address Workplace Bullying and Engagement: Results from a Cluster Randomized Controlled Trial

Background: Preventing workplace bullying may enhance work engagement. This study focused on fostering psychological safety as a shared approach to improving both. I developed a short-term intervention program for general employees to teach communication skills for proactively addressing problems in stressful situations and to provide a forum for shared understanding of the importance of sincere and necessary communication. Methods: A cluster randomized controlled trial was conducted with employees at a pharmaceutical company. Departments were randomly assigned to intervention or control groups. A generalized linear mixed-effects model was used to examine the intervention’s effects. Results: In the intervention group, tendencies to consult others in stressful situations and perceptions of psychological safety with superiors and teams significantly increased. Experiences of workplace bullying and feelings of intimidation by superiors significantly decreased. Work en-gagement declined in the control group but remained unchanged in the intervention group. Conclusions: Employees who participated in the program were more likely to express their opinions without excessive fear or withdrawal and to consult others in difficult situations. Although work engagement did not improve, it did not decline, suggesting the program maintained engagement while improving interpersonal communication and psychological safety. The group-based format encouraged mutual understanding and skill-sharing, contributing to a broader organizational impact. The findings suggest the program reduced workplace bullying by fostering sin-cere communication and teaching practical strategies for consultations, requests, and reporting.