Association Between Overtime-Working Environment and Psychological Distress Among Japanese Workers: A Multilevel Analysis

OBJECTIVE: The study aims to examine the association between overtime-working environment (OWE) and individual psychological distress among Japanese workers. METHODS: Data of 7786 workers from 101 companies in Japan were analyzed. Psychological distress was assessed through a 29-item questionnaire. The OWE was evaluated by calculating the proportion of workers whose monthly overtime was 45 hours or more in a workplace. Multilevel logistic regression was used. RESULTS: As 10% increase in the OWE was associated with a 16% higher risk of individual psychological distress after adjustment of individual covariates, including overtime working hours. Cross-level interaction showed that the risk was varied depending on individual overtime working hours. CONCLUSIONS: OWE was associated with the psychological distress of workers. It is necessary to create a non-OWE at workplaces to prevent psychological distress for workers.