• risk taking behaviour
• sustained attention

Healthcare workers who undertake night shifts play a crucial role in ensuring 24-hour patient care. However, as numerous studies have shown, sleep deprivation resulting from night shifts can reduce concentration and decision-making abilities. Shift work tolerance varies significantly among individuals based on sex, age, and chronotype.
The aim of the study was to evaluate the differences between men and women in terms of demographic variables, lifestyle habits, and the impact of night shifts on the neurocognitive performance of the subjects. Subsequently, the impact on cognitive performance of other variables associated with shift work tolerance, i.e., age, chronotype, sleepiness, and the quality of the night shift, regardless of gender was explored.
127 healthcare shift workers (68 females), including senior doctors, nurses, and residents from various departments of the University Hospital of Pisa and the Misericordia of Navacchio (Venerable Confraternity of Misericordia of Navacchio) participated in the study.
Five nights before the night shift, participants were given an actigraph to monitor physical activity and sleep. The actigraph was removed after the post-shift tests were conducted. Additionally, the individuals involved completed a series of questionnaires, including demographic questionnaires, the rMEQ (Morningness-Eveningness Questionnaire), DOSPERT (Domain-Specific Risk-Taking Scale), PSQI (Pittsburgh Sleep Quality Index), and KSS (Karolinska Sleepiness Scale), the latter administered both before and after the shift. Data on the participants’ habits and lifestyles were also collected. The results revealed that men have a notably higher BMI compared to women and consume more alcohol during the week. Coffee consumption is also higher among men, although showing only a trend towards significance. Women, on the other hand, spend more hours on household chores, an engagement that increases with age in both genders. No considerable differences were found between the two sexes in the parameters describing sleep, sleepiness, and chronotype, although the men in the sample surprisingly tend to be more morning-oriented than the women. In terms of cognitive performance, both men and women show comparable declines in reaction times post-shift compared to pre-shift. However, women have slower reaction times than men both at baseline and after the night shift. Regarding risk behaviour, at the end of the night shift, men show a greater propensity for risk compared to women, although no baseline differences were found. Advanced age predicts poorer performance on the PVT (Psychomotor Vigilance Test) both before and after the shift, while the performance decline is independent of age. Additionally, age is associated with less propensity towards risky behaviour.
Chronotype affects behavioural performance: morning types perform worse in the evening, while evening types perform worse in the morning. Subjective sleepiness, measured with the KSS, is strongly associated with a decline in PVT performance but shows no relationship with BART (Balloon Analogue Risk Task) results. Greater activation during the shift, measured in terms of steps taken, is associated with greater post-shift vigilance. Those who take fewer steps are less reactive. Finally, sleep quality, regardless of its duration, is strongly associated with more cautious behaviour. Considering the study results, it might be useful to personalise shifts based on chronotype and individual characteristics, such as assigning morning shifts to early risers and evening shifts to night owls. Additionally, less demanding shifts could be assigned to older staff (given their performance in the PVT). It could be beneficial to educate staff on techniques to improve sleep quality and raise awareness about the risks associated with drowsiness.
In the future, such interventions could be tested to evaluate their practical benefits. It might also be advantageous to use wearable devices to continuously monitor the biometric and sleep parameters of healthcare staff, in order to personalise shifts and support interventions. Furthermore, it would be interesting to conduct longitudinal studies to assess the long-term impact of night shifts on the health of healthcare personnel.