The Effect of Single and Double Shift Works on Salivary Cortisol Levels in Nurses

ABSTRACT Aim This study aimed to elucidate the effects of single versus double‐shift work schedules on salivary cortisol concentrations among nurses. Design This research was designed as a comparative descriptive study utilizing repeated measures to assess changes over time and shift types. Methods A total of fifty‐two female nurses, working in rotating shifts, participated in the study. Saliva cortisol samples were collected from all participants before, after, and at midnight for both a single and a double shift. To assess interactions between time (07:30–08:30, 15:30–16:30, 23:00–24:00) and shift type (single and double), a repeated‐measures two‐way analysis of variance (ANOVA) was used. Results Analyses encompassing both time and shift type demonstrated significant main effects for both variables. Salivary cortisol concentrations were maximal between 07:30 and 08:30, while the trough levels were recorded at midnight. Inspection of the main effect associated with shift type revealed that double‐shift workers exhibited higher mean cortisol concentrations. Specifically, cortisol levels were nearly two‐fold higher at midnight in double‐shift workers compared to single‐shift workers. Additionally, a significant interaction effect between time and shift type was found. Conclusion The pronounced effects of double shifts, as evidenced by significant changes in cortisol levels, warrant urgent consideration by healthcare policymakers and administrators, balancing operational efficiency with nurses' well‐being and patient safety. Patient or Public Contribution No patient or public contribution.