BACKGROUND: Decreases in subjective sleep quality are prevalent among nurses and midwives engaged in rotating shift work.
OBJECTIVES: The present study aimed to examine the relationship between differences in work schedules and subjective sleep quality among female nursing staff.
DESIGN: A cross-sectional survey design was used for descriptive and logistic regression analyses. Data collection was conducted from December 2016 to September 2017.
SETTINGS: Participants were recruited from five regional core hospitals in Japan.
PARTICIPANTS: A total of 1253 nurses and midwives were included in the final analysis.
METHODS: Subjective sleep quality was assessed using the Japanese version of the Pittsburgh Sleep Quality Index. Chronotype and social jet lag were calculated for both work day and work-free day. Symptoms related to restless legs syndrome/Willis-Ekbom disease were assessed using the Japanese version of the Cambridge-Hopkins questionnaire short form 13. Participants with the urge to move their legs, though not fulfilling the restless legs syndrome/Willis-Ekbom disease criteria, were classified as having leg motor restlessness. Logistic regression analyses for poor sleep were adjusted for age, body mass index, smoking, drinking, menstruation status, the presence of premenstrual syndrome, and the presence of a spouse.
RESULTS: Rates of poor sleep (Pittsburgh Sleep Quality Index score ≥6) among those working, day shifts, rotating 12.5 hour night shifts, rotating 16 hour night shifts, and three-shift rotations were 41.2%, 51.1%, 44.5%, and 60.4%, respectively. Approximately 40% of three-shift rotation workers experienced difficulty initiating sleep. Shift workers tended to exhibit evening chronotype, delayed sleep phase, and high social jet lag. The prevalence of restless legs syndrome/Willis-Ekbom disease was 2.5%. Leg motor restlessness was observed in. 15.5% of participants. The adjusted odds ratios (95% confidence interval) of three-shift work (vs. day shift), evening chronotype (vs. morning chronotype), and the presence of leg motor restlessness (vs. no leg motor restlessness) for those with poor sleep were 2.20 (1.47-3.30), 1.95 (1.29-2.94), and 1.66 (1.15-2.39), respectively.
CONCLUSIONS: Regardless of the working schedules, rates of poor sleep were high among female hospital nurses and midwives. Our findings suggest that poor sleep quality is influenced by three-shift rotation, the evening chronotype, and leg motor restlessness.
