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

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.