Night shifts and sleep among Chinese nursing students on internship

Shiftwork-induced sleep problems are major reasons for nursing students avoiding becoming nurses after graduation. However, research on the relationship between night shiftwork and nursing students' sleep during internship is limited. This study aimed to examine the impact of night shifts on sleep and to explore the dose-response relationship between the number of night shifts and sleep. Data were collected from nursing students on internship orientations in July 2022 (pre-internship) and 8 months later in March 2023 (post-internship). Participants (n = 571) were naturally categorized into two groups: day rotating shiftwork (DRS) if their shiftwork schedules without night shifts and night rotating shiftwork (NRS) if with night shifts. The pre- and post-internship sleep between the two groups were compared using mixed-effect models based on the difference-in-difference estimation to examine the impact of night shifts on sleep. Generalized additive models with penalized cubic splines and random intercepts were used to explore the dose-response relationship. After adjusting for inverse probability weighting, compared to the DRS group, the NRS group reported significantly lower fatigue/sleepiness levels during day shifts (β = -0.46, P < 0.001) and on rest days (β = -0.54, P < 0.001). The number of night shifts was associated with insomnia and fatigue/sleepiness in a dose-response manner. After the number of night shifts exceeded about 10, it was positively associated with insomnia and fatigue/sleepiness. Although Chinese nursing students working night shifts showed reduced fatigue/sleepiness compared to their counterparts working rotating day shifts only, with the increase in the number of night shifts, their insomnia and fatigue/sleepiness deteriorated.