Sleepiness During Night Shifts and Nurses' Self-Reported Cognitive Control, Cognitive Flexibility, and Handover Effectiveness: A Cross-Sectional Study.

AIMS: This study aimed to investigate the association between sleepiness and nurses' self-reported cognitive control, cognitive flexibility, and self-reported shift handover effectiveness during night shifts. BACKGROUND: Nurses are exposed to sleep deprivation during night shifts, constituting a substantial risk to both patient safety and workplace safety. METHOD: This descriptive study was conducted between January and June 2025 at a tertiary university hospital in Türkiye. The sample comprised 270 nurses employed in emergency departments, intensive care units, and medical/surgical wards. Data were collected using a Descriptive Information Form, the Visual Analog Scale, the Handover Evaluation Scale, and the Cognitive Control and Cognitive Flexibility Scale. EQUATOR CHECKLIST: This study was reported in accordance with the STROBE checklist. RESULTS: The nurses' mean sleepiness score was 6.41 ± 1.81. The mean sleepiness scores at midnight, 03:00 a.m., and 06:00 a.m. were 4.40 ± 2.62, 7.26 ± 2.17, and 7.58 ± 2.35, respectively. According to the analyses, higher sleepiness was associated with lower self-reported cognitive control and cognitive flexibility (β = -0.510, r = -0.379, p < 0.001) and lower self-reported shift handover effectiveness (β = -0.670, r = -0.619, p < 0.001). Additionally, a statistically significant indirect association between sleepiness and self-reported shift handover effectiveness through self-reported cognitive control and cognitive flexibility was observed (standardized β = -0.107, 95% BC CI: -0.257 to -0.023). The goodness-of-fit indices of the structural equation model indicated an acceptable model fit (CMIN/DF = 1.525, RMSEA = 0.044, CFI = 0.989). CONCLUSION: Higher night-shift sleepiness was associated with lower self-reported cognitive control and cognitive flexibility, as well as lower self-reported shift handover effectiveness. The findings highlight the importance of recognizing sleepiness as an occupational health concern and support further investigation into organizational strategies to reduce sleepiness and support nurses' cognitive functioning during night shifts. IMPLICATIONS FOR NURSING AND NURSING POLICY: Sleepiness among night-shift nurses should be recognized as an important occupational health and workforce concern. Healthcare organizations may consider monitoring sleepiness and exploring strategies to support nurses' cognitive functioning during night shifts. However, further multisite longitudinal and intervention studies are needed to determine the effectiveness of specific scheduling and fatigue-management interventions.