In the field of healthcare and medical sciences, nurses are the unsung heroes who provide round-the-clock care to patients, ensuring their well-being and safety. However, the nature of their work often requires them to embrace unconventional schedules, including evenings, nights, and weekends, as healthcare facilities strive to maintain continuous coverage [1]. While this shift work arrangement allows for 24/7 patient care, it poses several challenges that can significantly impact the nurses’ own well-being and, consequently, the safety of patient care.

Nurses working in shifts face a substantial obstacle in the form of the disturbance of their intrinsic sleep-wake cycle, commonly referred to as the circadian rhythm. The task of aligning their internal body clock with the irregular working hours presents significant challenges. Consequently, this disruption frequently manifests as sleep disturbances and excessive sleepiness, impeding nurses’ ability to attain the requisite restorative sleep. Insomnia or fragmented sleep may afflict them, leading to a chronic sleep deficit. Consequently, nurses often grapple with overwhelming drowsiness during their working hours, thereby compromising their cognitive capacities, attention span, and decision-making abilities [2]. The amalgamation of shift work and sleepiness substantially amplifies the likelihood of incidents and errors among nurses, thereby ultimately imperiling the safety of their patients.

Furthermore, an enduring consequence experienced by numerous nurses engaged in shift work is chronic fatigue. The profound toll it exacts on their physical and mental welfare becomes evident as they contend incessantly with persistent exhaustion. The demanding and irregular nature of their work schedules renders them vulnerable to sustained weariness, which not only compromises their quality of life but also impedes their ability to execute their duties optimally [3]. Characterized by perpetual sensations of tiredness, diminished energy levels, and physical depletion, this chronic fatigue detrimentally affects their alertness and overall performance, thus further augmenting the probability of incidents transpiring within the healthcare environment.

In order to prioritize the well-being of nurses and ensure optimal patient care, a comprehensive understanding of the complex interrelationships among shift work, sleepiness, chronic fatigue, and incident occurrence is crucial. By thoroughly examining these factors, healthcare organizations can develop effective strategies and interventions to mitigate the risks associated with shift work, thereby enhancing the safety and welfare of both nurses and patients [4].

The primary aim of this study is to investigate the intricate relationship between shift work, sleepiness, chronic fatigue, and incident occurrence among nurses. Through a comprehensive exploration of these factors, the research seeks to gain valuable insights into the ways in which work schedules and sleep-related issues interact, ultimately influencing the likelihood of incidents. The findings from this study will contribute to the existing body of knowledge and inform future interventions and policies aimed at improving working conditions and safety for nurses in the healthcare industry. By identifying and comprehending the specific challenges faced by nurses working in shifts, such as sleep disturbances, excessive sleepiness, and chronic fatigue, this study will provide a humanizing perspective on the experiences of these dedicated professionals. It will illuminate the underlying mechanisms that link these factors to the occurrence of incidents. Furthermore, the research will generate evidence-based recommendations for healthcare organizations to implement measures that prioritize sufficient rest, mitigate fatigue, and reduce the risk of incidents among nurses working non-traditional shifts. Ultimately, the overarching objective is to enhance the overall well-being of nurses, promote patient safety, and optimize the quality of care delivered within healthcare settings.

Absolutely, understanding the factors that impact nurses’ performance is crucial for providing quality patient care. Workload, scheduling practices, breaks, and the work environment all play significant roles in nurses’ well-being and fatigue levels, which directly affect their ability to deliver optimal care [5].

Workload management is essential for nurses to avoid excessive fatigue and burnout. Healthcare organizations and policymakers can develop staffing models that distribute workloads evenly, ensuring nurses have manageable caseloads and sufficient time for recovery. Implementing policies that prioritize rest breaks and limit overtime can also contribute to mitigating fatigue [6].

Sleep quality and duration are vital for nurses to maintain their well-being and performance. Healthcare organizations can promote healthy sleep habits by providing conducive environments for rest, minimizing noise disruptions, and offering support for shift transitions. Educating nurses on the importance of sleep hygiene and providing resources for managing sleep disturbances can also be beneficial.

The work environment itself plays a significant role in nurses’ performance. Creating a supportive and safe environment that promotes open communication, teamwork, and effective leadership can positively impact nurses’ well-being and job satisfaction [7]. Addressing issues such as workplace violence, physical demands, and emotional stressors can contribute to a healthier and more fulfilling work experience for nurses.

By addressing these factors and implementing supportive measures, healthcare organizations and policymakers can prioritize the well-being of nurses. This not only benefits the nurses themselves but also enhances patient safety and the overall quality of care provided. Creating a supportive work environment means promoting healthy sleep habits, addressing workplace stressors, and providing resources and spaces for nurses to rest [8]. This kind of environment can help reduce fatigue and empower nurses to deliver safe and effective care. By understanding these factors and taking appropriate actions, we can better support nurses in their work. It enables healthcare organizations to prioritize their well-being, reduce the risks associated with fatigue, and ultimately improve patient safety. It’s essential to create a culture that values the health and performance of nurses so that they can continue to provide the best possible care to those in need.

Several studies have been conducted to address the points mentioned, providing valuable insights into the factors that impact nurses’ performance and the strategies to mitigate the risks; for example, Samaha et al. [9] revealed that mood disturbance, locus of control, and trait anxiety were significant predictors of chronic fatigue, while poor sleep quality emerged as the strongest lifestyle factor contributing to fatigue. Other lifestyle predictors included higher workload perception, lack of exercise, and the non-availability of support. Additionally, coping strategies involving alcohol use, emotional expression, and avoidance of the situation were found to significantly predict chronic fatigue

Jason et al. [10] tried to examine the prevalence of chronic fatigue syndrome (CFS) among nurses, an area that has received limited attention in the research community, particularly within the context of healthcare professionals. Two groups of nurses were recruited, and data collection involved distributing questionnaires to capture demographic characteristics and CFS-related symptoms. Nurses with CFS-like symptoms underwent structured clinical interviews and medical record reviews. The study aimed to shed light on the prevalence of CFS among nurses and contribute to the existing knowledge base. The findings have implications for understanding CFS within the nursing profession and may guide future research on this topic. Pietroiusti et al. [11] stated that night-shift work has been linked to ischemic cardiovascular disorders, but it’s still uncertain whether it directly causes metabolic syndrome (MS), a risk condition for such cardiovascular issues. MS involves visceral obesity and minor disruptions in glucose, lipid levels, and blood pressure. In this study, researchers compared the experiences of 2-shift nurses and 3-shift nurses in terms of fatigue, quality of life, turnover intention, and safety incidents. In a study by Hong et al. [12], the findings revealed that the 2-shift nurses had some advantages. They reported feeling less tired and better able to recover between shifts, which made a significant difference in their overall well-being. They also had higher scores in terms of quality of life, indicating a better quality of life overall.

Interestingly, there were no notable differences between the two groups when it came to turnover intention or the frequency of safety incidents like needle stick accidents or medication errors. This suggests that both groups were equally committed to their work and maintained a similar level of safety precautions.

The 2-shift nurses expressed that their shift system allowed them to have more downtime and personal time for themselves, which greatly contributed to their overall job satisfaction. Additionally, their shift system enabled them to provide consistent and uninterrupted care to their patients, which is crucial for ensuring quality healthcare.

The study found that a significant majority of Thai nurses, approximately 75.9%, experienced short sleep duration. This indicates that many nurses were not getting enough sleep on a regular basis. Additionally, a considerable number of nurses reported experiencing fatigue (38.2%) and excessive daytime sleepiness (49.5%). Occupational errors were reported by 11.7% of the nurses, with medication errors being the most common. Although there was a higher incidence of occupational errors in the “Short Sleep Duration” group, the difference did not reach statistical significance. However, there was a significant association between short sleep duration and excessive daytime sleepiness. This highlights the importance of adequate sleep for nurses’ well-being and performance [13]. Batak et al. [14] believed that shift workers reported significantly higher fatigue levels across all Piper Fatigue Scale items compared to non-shift workers. The study emphasizes the importance of developing suitable working schedules to address the challenges associated with shift rotation and duration, aiming to reduce the negative impact of fatigue on nurses’ well-being and overall performance. Sagherian et al. [15], in a descriptive cross-sectional study, examined the relationship between fatigue, work schedules, and perceived work performance among hospital nurses. The sample included 77 bedside nurses, mainly female and in their 20s. Nurses who worked on their off days reported higher levels of chronic fatigue compared to those who took time off. In addition, working more than 8 night shifts per month is associated with an increased likelihood of nurses experiencing insomnia, fatigue, and depression [16]. Feeling refreshed after sleep was associated with lower levels of chronic and acute fatigue and better recovery between shifts. Fatigue was linked to perceived poorer physical performance, reduced alertness, difficulty concentrating during patient care, and less effective communication. Scott et al. [17] determined several factors as contributing to the likelihood of drowsy driving episodes. These included shorter sleep durations, working night shifts, and experiencing difficulties in staying awake during work. The study emphasizes the need for increased awareness among nurses regarding the risks associated with drowsy driving. Additionally, the implementation of strategies to prevent drowsy driving episodes is recommended to ensure public safety. A study by Wang et al. [18] found that there is a direct relationship between occupational stressors and insomnia among nurses, and nurses and nursing managers should take steps to improve the psychological resources and resilience of nurses in order to mitigate the negative effects that occupational stress has on insomnia.

The study concludes that without appropriate measures to address the issue, fatigued nurses will continue to present a risk not only to themselves but also to the general public. It highlights the importance of mitigating the occurrence of drowsy driving among nurses through awareness campaigns and preventive interventions.

Zdanowicz et al. [19] examined the level of insomnia, sleepiness, and fatigue among nurses. Various scales were used to measure these factors. The findings indicated that a significant proportion of nurses reported experiencing insomnia and exceeding the threshold for fatigue compared to the general population. There was a correlation observed between insomnia, sleepiness, and fatigue. The study concludes that addressing these issues is crucial in preventing health hazards and reducing the risk of errors at work due to increased sleepiness and fatigue among nurses. In the Australian context, Dorrian et al. [20] reported that nurses experiencing exhaustion, stress, and struggled to remain awake during approximately one-third of their shifts. Sleep duration was significantly reduced on workdays compared to days off, and further reduced on workdays when an error was reported. This suggests a potential link between sleep deprivation and the occurrence of errors, and a study by Demir and Karadag [21] indicated that as the sleep quality worsened, the tendency of nurses to commit medical errors increased. The present study aimed to evaluate the correlation between shift work, sleepiness, chronic fatigue, and incident occurrence among educational hospital nurses.

In this study, we had the valuable participation of 143 female nurses and 57 dedicated male nurses, representing both those who work in shifts and those who work regular hours. Among the 67 incidents that occurred, 57 of them took place within the hospital, with 47 incidents involving our hardworking nurses on shift and 10 incidents involving nurses who work regular hours. Interestingly, there were 10 incidents that happened outside the hospital, with 9 of them involving our resilient nurses on shift and 1 incident involving a nurse who works regular hours (Table 1).

The findings of the study revealed that male and female nurses working in shifts experienced mild levels of sleepiness. In contrast, nurses who did not work in shifts had an average level of sleepiness considered normal. It was also interesting to note that male nurses working in shifts showed signs of fatigue, while the rest did not display such symptoms.

When looking at the incidents that occurred within the hospital, it was found that nurses involved in these incidents reported moderate levels of sleepiness and chronic fatigue. However, for incidents that took place outside the hospital, the shift-working nurses experienced more severe sleepiness compared to their non-shift-working counterparts.

Table 2 presents the percentage of nurses who experienced incidents, categorized by their shift work and their exposure to fatigue and sleepiness. It was striking to see that a significant majority of nurses (86.7%) who experienced incidents showed signs of CFS and sleepiness, particularly among those working in shifts. Moreover, among the nurses in the shift-working group who experienced incidents, 76.9% reported feeling sleepy, while chronic fatigue symptoms were not evident.

In order to examine the impact of shift work on incident occurrence, as well as the influence of sleepiness syndrome and chronic fatigue of a specific type, a path analysis known as GSEM was utilized. The reason for employing this model was to investigate the mediating role of fatigue and sleepiness variables in the relationship between shift work and incident occurrence. In other words, shift work was hypothesized to have an effect on these disorders or syndromes, which in turn led to incidents.

Firstly, it was necessary to ensure the presence of a complete effect model (total effect) by fitting the data. This model was subsequently fitted, and with a p-value of 0.001, the existence of a relationship between shift work and incident occurrence was confirmed. In the next stage, the mediating role of the two variables, sleepiness syndrome and chronic fatigue, was examined. According to this model, both paths from shift work to the mediating variable and from the mediating variables to incident occurrence were found to be significant for both mediating variables.

The examination and impact of all paths involving mediating variables on incident occurrence can be observed in Fig. 1. As shown in the table below, despite the description provided by the two mediating variables, the direct relationship remained statistically significant. In other words, the mediating variables partially played a role in this relationship.

To investigate the influence of shift work on incidents and the role of sleepiness syndrome and chronic fatigue as mediators, a path analysis called GSEM was employed. The purpose of using this model was to explore how fatigue and sleepiness variables mediate the relationship between shift work and incident occurrence. Essentially, the hypothesis was that shift work affects these specific disorders or syndromes, which, in turn, contribute to incidents.

Firstly, it was important to establish the presence of a complete effect model (total effect) by fitting the data. Once the model was fitted, the results confirmed a significant relationship between shift work and incident occurrence, as indicated by a p-value of 0.001. Moving forward, the mediating role of two variables, sleepiness syndrome and chronic fatigue, was examined. According to the model, both pathways—from shift work to the mediating variable and from the mediating variable to incident occurrence—were found to be significant for both mediators.

By considering all the paths involving the mediating variables, their impact on incident occurrence can be observed in Fig. 1. While the two mediating variables partially explained the relationship, it is important to note that the direct relationship between shift work and incidents remained statistically significant. In other words, the mediating variables only accounted for a portion of the relationship.

As a result, the final model was derived and presented in the form of a table and a figure. Based on the estimated coefficients of this model, it can be inferred that when accounting for the mediating effects of sleepiness and fatigue variables, the likelihood of incidents occurring in shift-working nurses is approximately 3.6 times higher compared to non-shift-working nurses (Table 3).

The primary objective of this research endeavor was to delve into the relationship between shift work, sleepiness, chronic fatigue, and incident occurrence among nurses. By conducting a comprehensive exploration of these factors, we acquired invaluable insights into the interplay between work schedules and sleep-related issues that impact the risk of incidents. The findings of this study hold significant implications for healthcare organizations seeking to enhance the working conditions as well as safety of nurses within the healthcare industry.

Consistent with prior investigations, our study revealed challenges faced by nurses engaged in shift work, such as sleep disturbances, excessive sleepiness, and chronic fatigue. These challenges can be attributed to the disruption of the circadian rhythm and the irregularity of their working hours. The chronic sleep deficit experienced by nurses working in shifts jeopardizes their cognitive abilities, attention span, and decision-making skills; thus, elevating the risk of incidents and errors in patient care is highly potential for them.

Existing literature confirms our findings about the impact of workload, scheduling practices, availability of breaks, and the quality and duration of sleep on nurses’ performance and fatigue levels. Studies by Samaha et al. [9] and Jason et al. [10] have emphasize factors such as sleep quality, and the prevalence of CFS in contributing to nurses’ fatigue levels [9]. Furthermore, Pietroiusti et al. [11] have reported a correlation between night-shift work and ischemic cardiovascular disorders, indicating potential health risks associated with shift work.

In our study, we compared the experiences of nurses working two shifts with those working three shifts in terms of fatigue, quality of life, turnover intention, and safety incidents, drawing upon the findings of Hong et al. [12]. The results revealed that nurses engaged in two shifts reported feeling less fatigued, better able to recuperate between shifts, and enjoying a higher overall quality of life compared to their counterparts in three-shift schedules. Nonetheless, both groups demonstrated a similar level of commitment to their work and maintained comparable levels of safety precautions, suggesting that the dedication to patient care remained uncompromised by the shift system. Furthermore, our study shed light on the prevalence of short sleep duration, fatigue, and excessive daytime sleepiness among nurses. These findings align with studies conducted by Chaiard et al. [13] and Batak et al. [14], which underscored the adverse impact of sleep deprivation and fatigue on nurses’ well-being and overall performance. The association between short sleep duration and excessive daytime sleepiness underscores the crucial role of adequate sleep in promoting nurses’ well-being and optimizing their performance.

The implications of our study carry immense significance for healthcare organizations and policymakers. By gaining a deeper understanding of the specific challenges encountered by nurses engaged in shift work, interventions can be devised to prioritize adequate rest, mitigate fatigue, and reduce the risk of incidents. Staffing models that account for manageable workloads, sufficient recovery time, and supportive work environments can contribute to enhancing nurses’ well-being and improving patient safety. Establishing a culture that values the health and performance of nurses is a pivotal factor in sustaining the delivery of high-quality care.

Notwithstanding the valuable insights gleaned from this study, it is important to acknowledge certain limitations. Firstly, the study sample was confined to a specific geographic region and may not be representative of the entire nursing population. Secondly, data collection relied on self-report measures, which are susceptible to response bias. Future research endeavors should consider including larger and more diverse samples, employing objective measures of fatigue and incident occurrence, and adopting longitudinal designs to further validate and expand upon these findings.

Previous studies have shown that shift work increases the incidence of accidents. Moreover, the literature shows that there is a significant relationship between shift work and accident occurrence [24,25]. It is believed that sleepiness and chronic fatigue are recognized as influential factors in both occupational and non-occupational accidents. This relationship is noticeable in shift work occupations because the repeated changes in sleep and wake times, can lead to disruption in sleep patterns [26]. For instance, in a study conducted by Williamson and Feyer [27] they indicated that sleepiness can double the risk of accidents. This study emphasizes that insufficient sleep and poor sleep quality can lead to decreased cognitive performance and increased human errors. In a similar vein, Saremi and colleagues found a significant association between the frequency of traffic accidents and fatigue intensity [28]. This has been also stressed by Horne and Reyner [29] found a significant relationship between fatigue and accident occurrence. These findings highlight the importance of sleep management in work environments, especially for individuals working night shifts.

Similar results to our study were found in the study by Shen et al. [30], where night shift workers experienced higher fatigue compared to day shift workers, and a statistically significant relationship was observed. Jansen et al. [31] also aligned with the findings of the study, since they found a strong relationship between fatigue and shift work. Several studies have shown that shift work is a significant factor in the development of fatigue [32], although the study conducted by Akerstedt and Folkard [33] did not find a significant relationship between shift work and fatigue, which was not consistent with the results of this study.

Multiple studies aligned with our research and observed a significant association between sleepiness and shift work [24,34-38]. Previous studies have shown that driving after a night shift increases the risk of traffic accidents [26]. A review study indicated that the risk of accidents in individuals working long shifts is doubled [39]. Another review study by Duchon and Smith [40] revealed that six out of seven studies confirmed that long working hours and shift work increase the number of occupational accidents, consistent with our study, while one study showed a decrease in occupational accidents after a 12-hour shift but did not confirm our findings. Studies by Saraei et al. [41], Ryu et al. [42], and Halvani et al. [43] also confirmed this relationship. The study by Alali et al. [44] on shift work and occupational accidents aligns with our findings, confirming a significant relationship between shift work and occupational accidents.

There were several limitations in this study. First, using self-report measures that may influenced responses. To address this threat, participants were assured that the questionnaires were anonymous and data were confidential. Next limitation is that in the present study it was assumed that each nurse has a normal workload, but it should be noted that some nurses have had more than standard load in and out of the hospital which can affect individual fatigue levels. Therefore, assessing the exact workload of nurses was challenging. In addition, the time interval between night shifts and the number of nurse shifts in a month were among the other study limitations. Nevertheless, the researchers attempted to minimize study limitations; thus, they designed a cross-over randomized clinical trial and selected nurses with an equal number of night shifts.

In light of the findings, the most common complaint resulting from shift work is sleepiness since it leads to chronic fatigue and, consequently, a lack of precise concentration and performance. The study results showed that more accidents occurred among nurses working shifts who had some symptoms of chronic fatigue and sleepiness. Based on the impact of shift work, chronic fatigue, and sleepiness on the occurrence of accidents, fundamental measures should be taken to manage shift schedules. Considering the implications mentioned, careful attention to the work scheduling and shift patterns for nurses, so that sleepiness, fatigue and accidents could be reduced accordingly. In conclusion, the findings of the present study significantly contribute to the understanding of the relationship between shift work, sleepiness, chronic fatigue, and incident occurrence among nurses. The findings stressed the challenges faced by nurses engaged in shift work to prioritize their well-being and ensure patient safety. Healthcare organizations can foster supportive work environments that promote adequate rest and mitigate the risks associated with fatigue by implementing evidence-based interventions and policies. Ultimately, these endeavors will enhance nurses’ overall well-being, optimize the quality of care provided, and improve patient outcomes.