Temporal changes in self-reported sleep quality, sleep duration and sleep medication use in relation to temporal changes in quality of life and work ability over a 1-year period among Finnish municipal employees.

In this prospective follow-up study, we aimed to examine whether changes in self-reported sleep quality, sleep duration, and sleep medication use are temporally associated with changes in quality of life and work ability in municipal employees when several confounding factors are considered. The study was conducted in Finland among 637 municipal employees (88% women, mean [SD] age 48 [10] years) in 2014 and 2015. Information about the participants was collected by self-administered questionnaire and from medical history. Predicting variables were changes in self-reported sleep quality, sleep duration, and sleep medication use. Outcome variables were changes in the EUROHIS-QOL eight-item index and the Work Ability Score. Improved or unchanged sleep quality compared to worse sleep quality were associated with a preferable change in quality of life (both p < 0.001). No change in sleep duration compared to a decrease and no change in sleep medication use compared to increased use were also associated with favourable changes in quality of life. Increased use of sleep medication was associated with a decline in work ability, and the change in Work Ability Score also differed significantly between improved and worsened sleep quality. In this study, changes in sleep were widely associated with changes in quality of life and work ability of municipal employees. Programmes aiming for better sleep health would probably be beneficial both from a health-oriented and an economical point of view. Special attention should be paid to employees with a need for sleep medication.