Assessment of the Relationship between Sleep Disorders and Circadian Type in Nurses with Shift and Daytime Work

Chronotypes vary in different people, and the daily function outside of the framework of this rhythm can affect the quality of work. This study aimed to investigate the association between sleep disorders and chronotypes among the shift and day work nurses.

This cross-sectional study was performed among nurses in two teaching hospitals in Mash-had, Iran, during 2016-2017. A total of 180 randomly-selected nurses were divided into shift work and day work groups. Participants completed demographic information form, Circadian Type Inventory (CTI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI).

A total of 180 female nurses (90 participants in each group) with a mean age of 35.62 ± 4.07 years were stud-ied. The prevalence of rigid circadian rhythm in the day work group (93.3%) was significantly (P = 0.004) higher than shift work group (78.9%). However, the groups did not show any significant difference regarding the languid/vigorous (LV) index of the CTI (P = 0.080). There was a significant difference in the mean score of CTI between individuals with rigid and flexible circadian rhythms in the shift work group (P = 0.021).

In the present study, although there was no association between circadian type and sleep problems includ-ing insomnia and daytime sleepiness in shift work nurses, we observed the capability of coping with working in the rotating shifts in nurses with flexible circadian rhythms.