Parasomnias are more frequent in shift workers than in day workers.

The aim of this study was to investigate whether different shift work schedules were associated with nonrapid eye movement (NREM)- and/or REM-related parasomnias. A total of 2198 nurses with different work schedules participated in a longitudinal cohort study. The parasomnia questions were included in the fourth wave of the data collection, with a response rate of 74.1%. Logistic regression analyses with the different parasomnias as dependent variables were conducted. Nurses working two shift (day and evening) and nurses working three shift (day, evening and night) rotational schedules had increased risk of confusional arousal, a NREM-related parasomnia, compared to nurses working daytime only (odds ratios = 2.10 and 1.71, respectively). Similarly, nurses working two and three shift rotational schedules had increased risk of nightmares, a REM-related parasomnia (odds ratios = 1.64 and 1.57, respectively). The other parasomnias were not significantly associated with work schedule. Working night shifts only was not associated with any of the parasomnias. In conclusion, confusional arousal and nightmares were more commonly reported by nurses working rotational shift work schedules compared to nurses working daytime only. This is likely related to the circadian rhythm misalignment and sleep deprivation caused by such shift schedules.