Healthcare workers such as nurses provide continuous services around the clock; as a result, they are at a high risk for decreased sleep quantity and quality, continuous sleep deprivation, and cumulative sleep debt (Caruso, 2014; Geiger-Brown et al., 2012). Fatigue resulting from short and poor sleep as experienced by nurses tends to reduce their ability to concentrate and make correct decisions, leading to the possibility of errors and injuries (Scott, Arslanian-Engoren, & Engoren, 2014). Sleep deprivation, sleepiness, and fatigue were consistently associated with nurse performance and patient safety, which are important public concerns (Caruso & Hitchcock, 2010; Lockley et al., 2007).

Shift work has been consistently identified as a contributor to short and poor sleep of nurses. Working at night or on a rotating schedule can lead to misalignment between the timing of the biological clock and the work/sleep schedule, resulting in poor and shortened sleep during the day (Roach, Fletcher, & Dawson, 2004). Perkins claimed that nurses who sleep during the day(night shift nurses)obtained 4 hours less sleep than night sleepers (day shift nurses), and night shift nurses may accumulate a significant number of hours of sleep debt, leading to long-term exhaustion (Perkins, 2001). One study estimated that accident rates increased by 50%–100% for employees working long or irregular shifts (Wagstaff & Sigstad Lie, 2011).

Besides shift work, many other work factors may cause poor sleep of nurses, such as physical and psychosocial work strain (Geiger-Brown & Lipscomb, 2010; Zhang, Punnett, McEnany, & Gore, 2016). Previous studies have reported that workers with higher perceived stress had a significantly shorter sleep duration and worse sleep quality than workers with lower perceived stress (Charles et al., 2011; Kashani, Eliasson, & Vernalis, 2012). The work stress may also conflict with family responsibilities, such as childcare and eldercare, further contributing to poor sleep of nurses (Jacobsen et al., 2014; Zhang et al., 2016).

In addition to work factors, other identified risk factors for reduced sleep quantity and/or quality in other occupational groups or the general population include sociodemo-graphics such as older age (Green, Espie, Hunt, & Benzeval, 2012; Marquiae, Folkard, Ansiau, & Tucker, 2012), female gender (Green et al., 2012), African American racial group (Tomfohr, Pung, Edwards, & Dimsdale, 2012), unmarried status (Troxel et al., 2010), low income and low educational level (Paparrigopoulos et al., 2010), and having dependent family members (K. C. Lee, Yiin, Lin, & Lu, 2015). Disturbed/reduced sleep has also been linked to lifestyle factors such as smoking (Paterson, Dorrian, Clarkson, Darwent, & Ferguson, 2012), lack of physical activity (Farnsworth, Kim, & Kang, 2015), and poor health outcomes such as obesity (Buscemi, Kumar, Nugent, & Nugent, 2007), chronic diseases (Foley, Ancoli-Israel, Britz, & Walsh, 2004), and musculoskeletal pain (Takahashi, Matsudaira, & Shimazu, 2015).

Although there has been much research on shift scheduling, work stress, and its impacts on nurses’ sleep, the quantity and quality of sleep and their correlates in this specialty practice group of nurses are underexplored. The correctional environment exposes nurses to unique physical and psychosocial work stressors, especially workplace violence, which has not been examined for its impact on nurses’ sleep health. Therefore, the objective of this study was to examine a wide range of potential work and health correlates of sleep quantity and quality in correctional nurses.

In this study of 89 correctional nurses, over half (56.2%) reported short sleep duration (≤ 6 hours/day). This is a higher prevalence than in all U.S. workers (30%) in the National Health Interview Survey (Luckhaupt et al., 2010), than in U.S. nurses in the National Nurses’ Health Study (30%; Patel et al., 2004) and also than in nursing assistants (46%) from a large study of 18 nursing homes (Zhang et al., 2016). About a third (31.8%)of these correctional nurses reported poor sleep quality, which is a higher prevalence than in nursing assistants (23%) from the large study of 18 nursing homes (Zhang et al., 2016). These findings are of significant concern because short and poor sleep of correctional nurses could represent a threat to the safety and health of both patients and nurses themselves. The study found that night shift work was significantly associated with short sleep duration of correctional nurses, which is consistent with previous findings in the nursing workforce and the general worker population. Night shift requires work to occur during the biological night, whereas sleep would occur during the biological day; the resulting misalignment between internal circadian time and required work–rest schedules leads to shortened sleep. Night and rotating shift work have been continuously reported to cause reduced sleep quantity and quality (Lim, Hoe, Darus, & Bhoo-Pathy, 2018; Zverev & Misiri, 2009). Perkins claimed that nurses who sleep during the day normally obtain 4 hours less sleep than night sleepers (Perkins, 2001). On the basis of a national sample, Luckhaupt et al. reported that workers who usually worked the night shift were significantly more likely to report short sleep duration (44.0%)than those who worked the day shift (28.8%) or some other shifts (31.6%; Luckhaupt et al., 2010). Contrary to our expectation, night shift was not significantly associated with poor sleep quality in the multivariate Possion regression model with adjustment of covariates. A possible explanation for the nonassociation between night shift work and poor sleep quality may be related to the voluntary selection of night shifts (Moradi etal., 2014) and personal adaptation to night shifts (Boudreau, Dumont, & Boivin, 2013).

The study also reported a significant association between single marital status and short sleep duration. This is consistent with previous findings. The association between single marital status and short sleep duration has been reported in a large population study with Finnish adults (Lallukka et al., 2012). Another large population study of adults from Korea reported that being unmarried, including single and widowed/divorced status, was associated with abnormal sleep duration (Yoon et al., 2015).

On the other hand, the study found that MSDs, higher weight, and childcare responsibilities were associated with short sleep duration in the bivariate analyses, although these associations disappeared after adjusting for covariates. There may be a bidirectional relationship between sleep and MSDs (Koffel et al., 2016). Compromised or disrupted sleep is a known consequence of chronic pain (Kelly, Blake, Power, O’Keeffe, & Fullen, 2011), and individuals with MSDs that interfere with sleep are reported to perceive pain as more intense and have worse musculoskeletal outcomes (Schrimpf et al., 2015; Takahashi et al., 2015). Previous studies have reported associations between overweight/obesity and short sleep duration (Cappuccio et al., 2008; Wu, Zhai, & Zhang, 2014). Nurses, as informal caregivers of their own families, often sacrifice their sleep hours voluntarily to take care of their children and dependents, which explains the possible association between childcare responsibilities and short sleep duration.

Besides, in this study, we found that stress, depression, lower education, and younger age were associated with poor sleep quality in the bivariate analyses, although these associations disappeared after adjusting for covariates. Previous studies have reported that work stress was significantly associated with both short sleep duration and poor sleep quality (Charles et al., 2011; Kashani et al., 2012). Geiger-Brown and Lipscomb (2010) conducted a systematic review and reported a number of hazardous working conditions experienced by nurses and their associations with adverse health and safety consequences including poor sleep quality. Zhang et al. (2016) reported that, with each increase in beneficial work conditions, nursing assistants were less likely to experience short sleep duration and poor sleep quality. (Zhang et al., 2016). Quality sleep is essential to daily functioning. Both sleep quantity and quality have been closely associated with self-rated physical and mental health (Chasens, Twerski, Yang, & Umlauf, 2010; Faubel et al., 2009), and sleep problems were reported to have a significant impact on the mental health of nurses (Perry, Lamont, Brunero, Gallagher, & Duffield, 2015). In addition, low educational level was previously reported to be associated with both short sleep duration and poor sleep quality (Lallukka et al., 2012; Paparrigopoulos et al., 2010). Although the quality of sleep usually decreases with increasing age (Marquiae et al., 2012), one study found that age was a significant covariate of sleep quality among 760 nurses, with younger nurses reporting poorer sleep quality (K. Lee, 1992). Younger nurses could have more work and family responsibilities that may interfere with their sleep, causing poor sleep quality.

In addition, the study found that sleep quantity and quality shared different correlates, suggesting differentiating these two concepts in future research. Contrary to our expectations, the wide range of working conditions and work and health outcomes measured in this study, such as work-place violence and bullying, burnout, and others, were not significantly and directly associated with poor sleep outcomes. It is possible that individual physical and psychosocial work stressors assessed in this study were not strong enough by themselves to cause poor sleep outcomes; however, their collective effect may have had a significant impact on sleep outcomes of correctional nurses. This may also be attributed to the small sample size of the study and the use of selected items from standard instruments in measuring these variables, given the challenges of access to this study population and the collection of a wide range of data on work and health outcomes.

Considering the potential negative influences of nurses’ sleep on patient safety and nurses’ personal health and safety, correctional nurses are maintaining a high level of vigilance because of their safety and security concerns at work; as such, sleep becomes even more important for this specialty practice group of nurses. The study findings deserve particular attention in clinical forensic nursing practice. On the one hand, sleep is an important self-care domain (Dugan & Barnes-Farrell, 2018). Correctional nurses need to identify their own sleep problems and look for specific training in recognizing risk factors for sleep deficiency and how to cope with the impact of work on sleep. On the other hand, to examine the best practices to improve sleep of this specialty group of nurses at risk, future research should focus on the development of interventions targeting work schedule remodeling and shift work coping. Because night shift is not avoidable in this population of nurses, organizations and correctional nurses themselves could consider reducing the number of consecutive night shifts (Costa, 2010; Magee et al., 2016) and reducing the total number of monthly night shifts (Costa, 2010;Raminetal.,2015)to have better sleep, health, and recovery from work. Overtime has been a recognized risk in this State Correctional Healthcare System, and it may worsen the negative effect of night shift work on sleep and health (Buden et al., 2017); therefore, limiting overtime especially on night shifts, no matter whether it is voluntary or mandatory, should be implemented in the system.

Other organizational strategies that may improve sleep of correctional nurses include structuring work schedules to allow sufficient time for sleep and recovery between shifts, providing routine educational seminars on coping with shift work and healthy sleep hygiene practices, and establishing Employee Assistance Programs to support nurses who experience sleep deficiency, high psychological strain, or mental health problems. Previous studies also suggested that the health effect of nonstandard shift work is less severe if it is chosen by employees (Buessing, 1996); therefore, advocating for correctional nurses’ control over their work shifts may reduce the negative health and safety consequences resulting from irregular work schedules. In addition, management training on supporting staff in self-scheduling and decision making may indirectly reduce nurses’ work and family stress and mitigate the negative influences of shift work (Gillet, Fouquereau, Bonnaud-Antignac, Mokounkolo, & Colombat, 2013).