Objective: The aims of this study were to examine (a) whether employees with a chronic disease report more fatigue than employees without a chronic disease, (b) whether number or type of chronic disease is related to fatigue, and (c) whether differences in fatigue level in various types of chronic diseases are related to psychological distress.
Methods: Data were taken from 12,137 employees. Fatigue was measured with the Checklist Individual Strength (CIS).
Results: Employees with a chronic disease reported more fatigue (OR=2.9, 95% CI=2.7-3.2). Small differences were observed in the level of fatigue in various types of diseases. A strong linear association between the number of chronic diseases and fatigue was found. Psychological distress explained the higher level of fatigue in some chronic diseases (gastrointestinal diseases and migraine).
Conclusions: Fatigue is more common in employees with a chronic disease. A strong association between number of chronic diseases and fatigue exists. Fatigue in employees with a chronic disease can partly be explained by psychological distress. Some chronic diseases show a stronger association between psychological distress and fatigue.