Night today, day tomorrow: how irregular work shifts interfere with our psychological health.

The 24/7 economic activity has led to a growing demand for shift workers who now make up about 21% of the working population in Europe. Shift work causes desynchronization of biological and social rhythms and therefore increases the risk for physiological and psychological health issues. Night shifts, but in particular irregular shifts are considered to have numerous harmful effects on health and well-being. In this investigation, 185 shift workers employed at an Austrian railway company, filled in online questionnaires, which included the PSQI, the ESS, and items assessing sleep issues, their impact on life quality, and individual shift schedules. Results show that those shift workers who rated their shifts schedules as irregular reported significantly lower sleep quality according to the PSQI Global Score and the PSQI subscales subjective sleep quality, daytime sleepiness, and sleep duration. The probability of taking sleep medication was higher in shift workers whose schedules include more night shifts. In addition, participants who regularly worked on days after night shifts classified their complaints due to shift work as more severe. Future investigations should include more external and internal factors that influence the perception and handling of different working conditions. Nevertheless, our findings shed light on the particular situation of the railroad workers´population and show how important subjective perceptions are in dealing with shift work. The importance of sleep education and thematically relevant training becomes clear in order to prevent serious consequences on sleep and overall health.