Is physical and psychological work stress associated with fatigue in Danish ferry ship employees?

Fatigue is a recognised risk factor for safety in seafaring. While always dangerous, fatigue in ferry shipping is especially hazardous as it may jeopardise passengers' safety. To counteract fatigue, knowledge on its determinants is important. Little, however, is known on the influence from physical and psychosocial work environment factors within ferry shipping. The aim of the study was to investigate the association between work stress in terms of physical stressors, perceived job demands and job control and different dimensions of fatigue among ferry ship employees and to test whether a potential effect of work stress was mediated by sleep satisfaction.

The design was cross-sectional. 193 respondents answered to a self-administered questionnaire including standardised scales, i.e. the Swedish Occupational Fatigue Inventory and the Copenhagen Psychosocial Questionnaire for job demands and control. The association of risk factors with fatigue was determined using hierarchical multiple linear regression analyses.

Physical work stressors were positively associated with only one of five fatigue subscales: lack of energy. Higher levels of demands were related to more lack of energy, lack of motivation, physical exertion and sleepiness, while more control was related to lesser lack of energy, lack of motivation and sleepiness. No demand-control interaction was found. Effects of demand and control were partly mediated by sleep satisfaction.

Although limited by its cross-sectional design this study provides support for the independent relevance of demands and control for employee fatigue in ferry shipping and for a mediating role of sleep satisfaction.