Sleep quality according to chronotype in nurses working 8-hour shifts

Background To date, studies have been focused on sleep disturbances of nurses working during night shifts. There is a lack of understanding regarding the sleep quality of nurses working in the rapid rotation system for each type of shift work.Aims To determine the relationship between chronotype and sleep quality according to shift type (i.e. day, evening and night shifts) in nurses working 8-hour rotating shifts.Methods A cross-sectional, descriptive study was conducted from two tertiary hospitals in South Korea from December 2021 to September 2022, including nurses working 8-hour rotating shifts (N = 74). They completed questionnaires to measure general, occupational and sleep-related characteristics, chronotype, insomnia severity and daytime sleepiness. Additionally, sleep parameters were collected from actigraphy and sleep diaries for 7 days.Results A total of 64% of nurses had an evening chronotype and 37% of nurses had an intermediate chronotype. Nurses had significantly less total sleep time and worsened sleep latency and efficiency during the day shift compared to other shift types. Compared to nurses with an intermediate chronotype, those with an evening chronotype had poorer sleep quality during day shift work.Conclusions Strategies to enhance nurses' sleep quality during day shifts should consider a two-level approach: individual approaches, such as improving sleep hygiene, and administrative approaches, such as establishing a chronotype-based shift system for scheduling. Nurses' sleep quality across shift types varied depending on their chronotypes. Most nurses had an evening chronotype and poor sleep quality, especially during the day shift. Poor sleep quality during the day shift can be caused by both individual chronotypes and work intensity; hence, individual efforts for improving sleep and organizational strategies for flexible shift work design are needed.