BACKGROUND: Given the harmful effects of night shifts and rotating schedules on nurses' sleep and work performance, shift nurses' sleep patterns have been a research concern. Actigraphy involves acquisition of data using a movement sensor worn continuously on the nondominant wrist, typically for a week or more. Although actigraphy provides objective and accurate sleep data, sleep diaries have been a practical alternative. However, there is a lack of research on the agreement and consistency between the two methods of measuring sleep for shift work nurses. In addition, differences in sleep patterns by shift types among 8-hour fast-rotating shift work nurses has not yet been examined.
OBJECTIVES: To evaluate the agreement between the sleep diary and actigraphy methods for sleep assessment, and to compare sleep parameters of 8-hour fast-rotating shift work nurses according to shift type.
DESIGN: Descriptive and prospective study design.
SETTINGS: Two tertiary hospitals in Seoul, South Korea.
PARTICIPANTS: A total of 94 shift work nurses who wore actigraphy along with completing a sleep diary.
METHODS: Subjective and objective sleep parameters were recorded during a two-week period in a sleep diary and actigraphy, respectively. Bland-Altman plots and intraclass correlation coefficients were used to analyze the agreement between the two methods. Sleep parameters according to shift type were compared using the Kruskal-Wallis and Mann-Whitney U tests.
RESULTS: Good agreement was observed between the sleep diary and the actigraphy data for total sleep time (intraclass correlation coefficients = 0.765 or 0.858) and variability in sleep time (intraclass correlation coefficients = 0.838). When compared to the actigraphy data, diary-derived data were overestimated by 41-45 min for total sleep time and 0.4% for variability in sleep time. There was a difference of 2-3 h of sleep quantity by shift type: 5.3-5.8 h for day shifts and 7.1-8.4 h for night shifts.
CONCLUSIONS: A sleep diary can function as an acceptable alternative to actigraphy for measuring shift work nurses' sleep patterns, specifically total sleep time and variability in sleep time. Given the high variability in sleep among shift work nurses, both personal and organizational efforts are required. Nurses should monitor their sleep quantity and develop their own regular sleep schedules to fit their work schedules. Hospitals should establish healthy schedules for nurses to guarantee sufficient sleep hours before work. Future research on shift work nurses' sleep should examine fluctuations in sleep duration.
