Abstract
The objectives of this study were, firstly, to examine the association between job strain and sleep quality in a sample of primary and secondary school teachers and, secondly, to assess whether the relationship between job strain and sleep quality is mediated or moderated by an individual's inability to "switch-off" from work-related issues during leisure time. School teachers (N= 143) completed an hourly record of their work-related thoughts over a workday evening between 5 p.m. and bedtime, and then rated their sleep quality the following morning. Individuals were classified as reporting high (n=46) or low (n=52) job strain using predetermined cut-off scores. Consistent with previous research, the results showed that both groups demonstrated a degree of unwinding and disengagement from work issues over the evening. However, compared to the low job strain group, the high job strain teachers took longer to unwind and ruminated more about work-related issues, over the whole evening, including bedtime. There was no difference in total sleep time between the groups, but high job strain individuals reported poorer sleep quality compared to low job strain individuals. With respect to the second objective, across the whole sample (N= 143), work rumination and job strain were significantly correlated with sleep quality, but work rumination was not found to mediate, or moderate the relationship between job strain and sleep quality. It was speculated that the initial low contribution of job strain to sleep quality (r = -.18) may have contributed to this null finding. The current findings may have implications for how we assess and manage sleep disturbance in stressed workers.