Effects of nurses' schedule characteristics on fatigue

An integrative review of 21 studies found mixed results on the associations of work schedule and nurse fatigue. Suggestions for nurse leaders include monitoring fatigue in shift workers, ensuring supportive work design, promoting a healthy lifestyle, and implementing scheduling interventions.

the beginning of each month. The work assignments are arranged for up to 6 weeks at a time, and each department or unit generates its own schedule. 16 Adjustments and decisions need to be made daily, and there are many shift changes on short notice, as the nurse manager tries to resolve conflicts through consensus. 15,17 Schedules are constantly changing and the manager's role is demanding because the schedules also have to comply with government regulations. The objective is to find balance between satisfying individual preferences and minimizing personnel costs. 16,18,19 Workplace fatigue is recognized as a physiologic state of impaired performance, a multidimensional consequence of four main factors: sleep loss, extended time awake, working and sleeping at suboptimal times in the circadian body clock cycle, and excessive physical and mental workload. 20 Fatigue is an individual experience that's defined through five dimensions: lack of energy, muscle weakness, physical discomfort, decreased motivation, and insomnia. 21 There are also other indicators such as lack of power, slowness, and lethargy.
Nurses with acute and chronic fatigue report poorer physical performance, are less alert, and are less able to concentrate and communicate effectively when providing patient care. 22 Fatigue accumulates over time and negatively affects work performance, increasing the risk of workrelated injuries, musculoskeletal disorders, stress-related illnesses, and dissatisfaction. 23 Researchers have investigated the impacts of particular features of nurses' shift work to a limited extent. Smith-Miller identified some work characteristics (recuperation, shift work, rotating shift, 12 hours versus 8 hours, work environment, unit culture) affecting nurse fatigue. 14 Min also analyzed different characteristics of the work schedule (number of working hours per week, normal number of working hours per shift, overtime in the previous month, number of afternoon and night shifts per month, number of quick returns between shifts, day off work) and their impact on nurses' fatigue. 24 They found that the research results were inconsistent and the fatigue construct in each study was designed differently, and they concluded that there was insufficient evidence to confirm the association between shift-work characteristics and fatigue in nurses.
To develop strategies to effectively manage work-related fatigue in nurses, it's important to analyze scheduling in relation to fatigue.

Aim
The goal of the research is to examine the scientific literature to answer the question: What's they were published in peer-reviewed journals, had shift nurses as the study population, operationalized nurse fatigue as the dependent variable and scheduling patterns as an independent variable, investigated fatigue in employed nurses (LPNs and above), had mixed samples of healthcare workers, and were written in English the evidence that schedule characteristics are associated with work-related fatigue among hospital nursing staff working in shifts? Addressing this question will provide evidence that may help nurse leaders better understand the importance of managing the risks associated with shift work.

Design
Using a four-step search strategy, researchers conducted an integrative review of the literature (see Table 1) and reported the results in accordance with the Whittemore and Knafl guidelines. 25 In the initial search, investigators used Medical Subject Headings (MeSH) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) to identify suitable keywords and index terms and ensure no similar systematic review had been conducted in the last 3 years. A search strategy was developed for each database using Boolean operators (AND, OR, NOT) based on three key concepts: "fatigue," "nurses," and "scheduling." Six electronic databases were used in the searches: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, CINAHL, ProQuest Theses and Dissertations, and Web of Science. The time frame of the searches was up to August 2021. Lastly, the reference lists of relevant studies were manually screened to identify additional relevant studies.
The search results were imported and managed using EndNote X9 (Thomson Reuters, New York, US). Duplicates were removed electronically and then manually. The full texts of potential studies were retrieved and reviewed. The primary reviewer contacted study authors to obtain the full paper via ResearchGate or email if it wasn't available in the library. A second reviewer was also used throughout the selection process.

Search outcome
Investigators found 6,450 articles in the databases using the search method described above and evaluated the literature against fatigue and scheduling patterns. After removing duplicates and then examining the title, abstract content, and keywords, investigators chose 159 articles. The articles were then reviewed for quality using the CASP (Critical Appraisal Skills Programme) tool. 26 The PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) was used to report the article selection process (see Figure 1). 27 Twentyone articles were selected for final analyses (see Table 2). Most of them (n = 13) were crosssectional studies, six were Records excluded after title and keywords evaluation n = 5,904 Records excluded after evaluation of abstract n = 92 Full-text articles excluded n = 46 Records after duplicates removed n = 6,063 Full-text articles assessed for eligibility n = 67 Eligibility

Records screened n = 159 Screening
Studies included in synthesis n = 21 Included literature reviews, and two were case-control studies.

Data abstraction and synthesis
With the open coding system used for thematic analysis, investigators identified 53 codes, which were combined into four themes: fatigue symptoms, when/how schedule characteristics, schedule-related causes of fatigue, and organizational fatigue facilitators (see Table 3).

Findings
In the analyzed studies, the construct of fatigue was described with feelings of fatigue, fatigue-related clinical errors, intershift, acute or chronic fatigue, drowsiness, lack of energy, difficulties in concentrating, and feeling uncomfortable. [28][29][30][31][32][33][34][35][36] Work schedules that include overtime, more workdays, and night shifts are said to be a significant predictor of chronic fatigue in nurses. 37,38 The literature also describes the following schedule characteristics as important: rapid changes in schedule, the direction and speed of shift rotation, shift length (mainly 12-hour shifts), shift start and finish times, short breaks between shifts and quick returns, work on scheduled days off, and a high number of hours per week (over 60 hours) (see Table 4). 28,29,[32][33][34]37,[39][40][41][42][43] Moreover, some authors have addressed schedule patterns per se as a factor connected with fatigue. Garrubba [31][32][33]36,39,40 When and how shift work takes place can cause both acute and chronic fatigue, but according to some authors has no significant effect on the health of nurses or the feelings of fatigue. 24,28,31,44 Managers can facilitate employees' recovery from fatigue by simultaneously implementing healthy lifestyle promotion (with the focus on sleep promotion) and supportive work design-ensuring social support, greater work control, regular breaks, appropriate work and job demands, workplace autonomy, and high job control. 39,41,45,46 It's recommended to provide special monitoring of shift workers to recognize fatigue symptoms early. Managers should also control shift scheduling and implement scheduling interventions, such as avoiding overtime work and long work shifts, minimizing the number of night shifts and shift rotation, using forward rotation instead of backward rotation, and ensuring enough rest time between shifts (see Table 5). 24

Discussion
Our findings show that fatigue is common in nurses, but the evidence about its association with scheduling isn't consistent. Although much of the research identifies a relationship among nurse fatigue and different aspects of scheduling, there are also studies that claim shift work has no significant effect on fatigue.
Studies show the multidimensional nature of fatigue, includ-ing the variety of fatigue symptoms and measures used to assess it. Some research instruments directly measured fatigue symptoms (such as feelings of fatigue), but there were also studies with a wider research focus that included fatigue (such as the Shift Work Index). 24,28,[31][32][33][34][35][36]41 It seems that researchers can't agree on a representative instrument to measure different aspects of organization-related fatigue.
Because fatigue is subjective and the individual isn't necessarily aware of it, it's vital for the nurse manager to prevent and recognize the fatigue in employees at an early stage. 48 Authors suggest that leaders be alert to fatigue-related clinical errors, drowsiness, lack of energy, difficulties in concentrating, and discomfort. 32,36 Additionally, a standardized instrument to measure fatigue is needed.
Organizing a schedule is a challenge for nurse managers. It seems that shift work leads to fatigue regardless of the scheduling characteristics because fatigue originates from disruption of the circadian rhythm, insufficient  A statistically significant difference was observed in mean scores of total fatigue and physical and mental subscales between the two groups after core stability exercises. Barker and Nussbaum, 2011 Longer shift lengths and hours worked per week were associated with increases in physical and total fatigue levels. Mental, physical, and total fatigue levels also differed with shift schedule.

Dall'Ora et al., 2016
Shifts of 12 hours or longer are associated with jeopardized outcomes. Working more than 40 hours per week is associated with adverse events. Working rotating shifts was associated with worse job performance outcomes, whereas fixed night shifts appeared to enable resynchronization.  Two main aspects of shift design were considered-the direction of shift rotation and extended shift length (mainly 12-hour shifts). There's insufficient evidence to support definitive conclusions. The risk of sleep problems increased with roster changes, night shifts, and shift extensions greater than 30 minutes and decreased with more choices about shifts. Recalling a fatigue-related error was lower in more experienced nurses. Garrubba and Joseph, 2019 The two major causes of fatigue are disruption of circadian rhythm sleep and sleep deprivation. Fatigue can be caused by work-related factors, including roster patterns, length of shift, poor work scheduling and planning the timing of shifts, insufficient recovery time between shifts, and more.

Gifkins et al., 2020
Recovery from fatigue is most significantly affected by high work and job demands, when and how of shift-work schedules. Rotating shifts were associated with higher levels of fatigue in shift-working nurses when compared with day-only nurses. Geiger-Brown et al., 2012 Fatigue was high in one-third of nurses, with intershift fatigue (not feeling recovered from the previous shift at the start of the next shift) being most prominent. Han et al., 2014 Shift rotations were significantly associated with acute fatigue. In comparison, when work schedules are fixed on either day or night, nurses can adapt to their schedules and may find successful strategies to reduce fatigue and increase recovery. Hazzard et al., 2013 Despite high acute fatigue scores, intershift fatigue scores reflected recovery and chronic fatigue scores were low. Jones et al., 2015 Female gender was associated with higher stress levels and greater fatigue. Greater social support from supervisors or colleagues decreased stress and fatigue. Longer shifts were associated with a tired current state; personnel on rotating shifts had lower stress and better current state, whereas those on night shifts had greater sleep and energy difficulties. Jung and Lee, 2015 All variables except for three (number of children, body mass index, and working hours) were related to at least one of the symptoms associated with shift-work tolerance. Juniartha et al., 2020 There was a significant difference in the effects of the shift-work schemes on nurses' work-related fatigue. There was a significant difference in the influence of the work distribution system on work- The reviewed studies provided mixed results regarding the associations between work schedule characteristics and nurse fatigue. Ruggiero, 2003 Variables contributing to chronic fatigue are global sleep quality and depression. Day and night nurses had similar levels of chronic fatigue. Querstret et al., 2020 Longer shifts, shift patterns including nights, increased sleepiness, and levels of fatigue. The literature related to sleep-related/fatigue-management interventions for nurses and midwives is fragmented and lacks cohesion. Sagherian et al., 2017 Work schedules that include overtime and more workdays can result in fatigue.

Yuan et al., 2011
Differing work schedules result in differing levels of fatigue, with shift work attributed to higher levels than day work. Nurses who worked in shifts were more fatigued than nurses who worked during the day.
recovery time, and high work/job demands. [39][40][41]49 Managers should consider many characteristics of schedules (shift rotations, night shifts, quick returns, roster changes, overtime, length of shift, differing work schedules, work arrangements, roster patterns) that can disrupt employees' circadian rhythms. 24,28,[31][32][33]36,[39][40][41] Working in shifts is almost inevitable for nurses; the real dilemma is what schedule characteristics a manager should be most concerned about when trying to minimize nurse fatigue. The law prescribes the minimum time between shifts, the minimum days off per week, and the maximum work hours per week. Other schedule characteristics are mostly in the hands of, and a challenge for, the manager. Therefore, the nurse manager's awareness can be a factor that influences the schedule properties and consequently impacts fatigue in employees.
Nurses who work shifts are exposed to a great number of adverse reactions at the same time. Shift work affects bodily functions, most notably sleep, autonomic vegetative processes, and work ability. 50 Although difficult, it shouldn't be impossible to make a worker-friendly schedule, providing known recovery facilitators (at minimum) such as control over shift scheduling, breaks, and choice over shiftwork schedules. 32,39,41,46,51 Choice over shift-work schedules is maybe the most challenging. It could be a statement of workplace autonomy, but on the other hand, it can lead to frequent changes in schedule plans.
This review has a number of limitations. The most obvious is that shift work also includes night work, which is a known factor influencing fatigue. In some studies, shift work was used as a synonym for night work, and many studies concentrated on sleep quantity and quality. It was also difficult to compare the findings from studies because different measures were used, and researchers focused on different aspects of shift work. Although the impact of schedule characteristics on fatigue is unclear in the literature, it should be addressed in more detail in future research. We recommend case-control and longitudinal studies with standardized instruments, as well as research addressing additional variables (such as work-life balance and quality of life).

Conclusion
The reviewed studies provided mixed results on the associations of work schedule with nurse fatigue, although in most of the literature, varied work schedules contributed to nursing fatigue. This implies that a possible association between shift work and fatigue might depend on schedule characteristics. Amid a very disrupted workforce and global nursing shortage, staffing is an issue for most, if not all, nurse managers, and they should consider schedule characteristics that minimize fatigue. Increasing nurse leaders' awareness of work design and schedule characteristics that might impose fatigue, early screening of fatigue, and promotion of a healthy lifestyle could prevent and reduce the possible negative effects of working shifts and should be integrated in nursing staff management. NM