A longitudinal study of rotating shift type and attention performance of acute and critical care nurses with chronotype as moderator variable.

Objectives: To investigate whether chronotype is a moderator variable that also interacts with shift type and whether they jointly influence the attention performance of nurses working in acute and critical care units.

Methods: We adopted a longitudinal research design focusing on nurses working rotating shifts in the emergency room and intensive care units at a medical center. A total of 40 complete samples were obtained. Data analysis was conducted using the generalized estimating equations in SAS 9.4.

Results: The mean (SD) age of the participants was 26.35 (2.12) years. After controlling for age, gender, and sleep duration, an interaction effect was discovered between a specific chronotype and shift type; that is, the interaction effect between chronotype and shift type was only significant when comparing late-types working the night shift with early- and intermediate-types working the night shift (B = -18.81, P = .011). The least squares means of the mean reaction time of the interaction effects between the 2 chronotype groups and the 3 shift types found that the mean reaction time of late-types working the night shift was 11.31 ms (P = .044) slower compared with working the day shift.

Conclusions: The chronotype is a moderator variable between shift type and mean reaction time, such that matching the chronotype of nurses in acute and critical care units with the appropriate shift type improved their mean reaction time. It is hoped that the results of this study could serve as a reference for acute and critical care nurses when scheduling their shifts.