Moderators of the relationship between long work hours and health.

The authors examined how associations between work hours and self-reported health are moderated by the reasons given for working overtime, by schedule autonomy, and by the degree of social support experienced, in a survey of 372 train drivers. Respondents who lacked both schedule autonomy and social support demonstrated positive associations between the number of hours worked per week and frequency of physical health symptoms. Conversely, negative associations were observed among respondents reporting low schedule autonomy together with high social support. There were no such interactions in the analyses of fatigue and psychological health outcomes. The findings are discussed in terms of the fit between an individual's actual and desired work hours. The problems of identifying appropriate limits for work hours are highlighted.