Comparison of Sleep Duration, Social Jetlag, and Subjective Sleep Disturbance in Rotating Shift Nurses According to the Chronotype

ABSTRACT

Purpose@#The purpose of this study was to investigate the sleep duration, social jetlag (SJL), and subjective sleep disturbance according to the individual chronotype in rotating shift nurses. @*Methods@#A total of 344 rotating 3-shift nurses (mean age 28.67 years) were recruited at one university affiliated hospital. They completed the following questionnaires, which were used to assess their chronotype and sleep the morningness-eveningness questionnaire (MEQ), self-reported sleep duration of work days (SDW shift) and free days (SDF shift) in each shift (day [D], evening [E], night [N]), and sleep disturbance (Insomnia severity index, ISI). SJL shift was calculated as the difference in midsleep (MS = sleep onset+1/2 sleep duration) between work days (MSW) and free days (MSF). @*Results@#Subjects were divided into 3 chronotype groups according to the MEQ; morning (MG, 4.4%) intermediate (IG, 57.8%), and evening groups (EG, 37.8%). SDW D was shortest (4.68 hr) and SDF E was longest (8.93 hr) in the EG. SJL D was longest in the EG (3.77 hr), and SJL N was longest in the MG (7.37 hr). The prevalence of sleep disturbance was 33.3% (MG), 29.6% (IG), and 40.0% (EG), respectively, without any statistical significance. @*Conclusion@#In order to improve the sleep of shift workers, it is recommended that the evening chronotypes should reduce the day shifts and the morning chronotypes should reduce the night shifts. We also propose a study to determine whether these shift assignments can improve the sleep in shift nurses.