Moderating Effects of Psychological Job Strain on the Relationship between Working Hours and Health: An Examination of White‐Collar Workers Employed by a Japanese Manufacturing Company

Moderating Effects of Psychological Job Strain on the Relationship between Working Hours and Health: An Examination of White‐Collar Workers Employed by a Japanese Manufacturing Company: Kimio Tarumi, et al. Section of Postgraduates Guidance, University of Occupational and Environmental Health —The effects of working hours on health were examined taking psychological job strain into account. White‐collar workers employed at the main office of a Japanese manufacturing company provided data for analysis done in 1997. The eligible subjects were 286 workers aged 20–39. Causal relationships between working hours, health, and psychological job strain were examined by covariance structure analyses. The main findings were as follows: Not only working hours but also sleeping hours and vacations affected the workers’ effort to deal with work as a work‐related hour factor. Decision authority and skill discretion of Karasek's psychological job strain items significantly constituted a discretion in the work factor, and this factor moderated the effects of the work‐related hour factor on health. The effects of psychological job strain, especially discretion, must always be taken into account in examinations of working hours and health.