Buffering effects of job resources on the association of overtime work hours with psychological distress in Japanese white-collar workers.

Abstract

The purpose of the present study was to investigate the buffering effects of job resources, utilizing the job demands-control (or demand-control-support) and effort-reward imbalance models (i.e., job control, workplace social support, and extrinsic reward), on the association of overtime work hours with psychological distress in Japanese employees. A total of 1,198 participants (valid response rate = 93.7 %) from five branches of a manufacturing company in Japan completed a self-administered questionnaire comprising the scales assessing job resources, psychological distress, and demographic characteristics. We obtained the information on working hours in the most recent month from the personnel records of the surveyed company. Multiple logistic regression analyses were conducted. In a series of analyses, interaction term of overtime work hours with each job resource was included in the model. Significant interaction effect of overtime work hours with job control was observed. Among the low job control group, the long overtime (80 h or more) subgroup had a significantly higher prevalence odds ratio of psychological distress compared to the short overtime (44 h or less) subgroup. No significant association of overtime work hours with psychological distress was found among the high job control group. On the other hand, there was no significant interaction effect of overtime work hours with workplace social support or extrinsic reward. The present findings suggest that high job control has an effect on reducing psychological distress in relation to overtime work hours in Japanese employees.