Did a brief nap break have positive benefits on information processing among nurses working on the first 8-h night shift?

Effects of short naps during simulated night shifts on alertness and cognitive performance in young adults

While short daytime naps have been found to provide alertness and performance benefits without inducing sleep inertia, the effects of a similar napping strategy during nights shifts are largely unknown. This study examined the effects of a 20-min nap (scheduled at 2:00 a.m.) during night shifts among 16 participants (mean [SD] age 22.0 [1.08] years) who worked in a simulated night shift from midnight (12:00 a.m.) to morning (ending at 6:00 or 8:00 a.m.). The participants underwent both a 'nap condition' and a 'no-nap condition' by engaging in repeated 10-min tasks (four-choice reaction time tasks and vigilance tasks) and 10-min rest. The results showed that compared to the no-nap condition, sleepiness was significantly lower in the nap condition between 3:20 and 5:20 a.m. (p < 0.05). The nap condition also yielded significantly better performance in the vigilance tasks between 2:40 and 5:40 a.m., except at 4:40 am (p < 0.05). However, no significant difference was found in sleepiness and performance in the vigilance task at 5:40 a.m. or immediately after the nap between the two conditions. The results showed that a 20-min nap at 2:00 a.m. did not induce sleep inertia upon waking. Furthermore, it mitigated sleepiness and sustained work performance for 3 h after the nap. However, the effect of napping was no longer observed near the end of the night shift. Considering risks of falling asleep while driving home from work that may cause a traffic accident, further research should examine ways to mitigate sleepiness after a night shift.

Effects of 90 Min Napping on Fatigue and Associated Environmental Factors among Nurses Working Long Night Shifts: A Longitudinal Observational Study

For nurses working long night shifts, it is imperative that they have the ability to take naps to reduce fatigue, and that an appropriate environment is prepared where such naps can be taken. We verified the effects of 90 min napping on fatigue and the associated factors among nurses working 16-h night shifts. We investigated 196-night shifts among 49 nurses for one month. Wearable devices, data logging devices, and questionnaires were used to assess nap parameters, fatigue, and environmental factors such as the napping environment, ways of spending breaks, and working environment. Nurses who nap at least 90 min on most night shifts had more nursing experience. Multivariable logistic regression analysis showed that the environmental factors significantly associated with total nap duration (TND) ≥ 90 min were noise, time spent on electronic devices such as cellphones and tablets during breaks, and nap break duration. The night shifts with TND ≥ 90 min showed lower drowsiness after nap breaks and less fatigue at the end of night shift compared to those with TND < 90 min. Nurses and nursing managers should recognize the importance of napping and make adjustments to nap for at least 90 min during long night shifts.

A quasi-experimental study into the effects of naps and therapy glasses on fatigue and well-being

Aim

To investigate the effects of a napping facility and therapy glasses on fatigue and well‐being at the end of the night shift.

Background

Night shift work has adverse effects on fatigue and well‐being.

Methods

A quasi‐experimental study was conducted, and data were collected on 243 night shifts of 95 nurses who had either access to a napping facility, therapy glasses, both facilities or no facilities. Multilevel analyses were conducted to predict fatigue and well‐being.

Results

Night shifts of nurses having access to both facilities were associated with less fatigue and more well‐being. The use of therapy glasses related negatively to fatigue and positively to well‐being. The use of the napping facility was not associated with fatigue and well‐being. However, having slept while napping and sleeping time during napping were negatively associated with fatigue and positively associated with well‐being.

Conclusion

Therapy glasses and sleeping in a napping facility can be effective interventions in reducing the adverse effects of night shift work.

Implications for Nursing Management

Therapy glasses seem an effective investment to facilitate the well‐being of nurses. To enhance sleeping during napping, it is worthwhile to let nurses get accustomed to the napping facility and customize settings to personal preferences.

Improving fatigue risk management in healthcare: A scoping review of sleep-related/ fatigue-management interventions for nurses and midwives (reprint)

BACKGROUND

Nurses and midwives make up almost 50% of the global healthcare shift working workforce. Shift work interferes with sleep and causes fatigue with adverse effects for nurses' and midwives' health, as well as on patient safety and care. Where other safety-critical sectors have developed Fatigue Risk Management Systems, healthcare is behind the curve; with published literature only focussing on the evaluation of discreet sleep-related/fatigue-management interventions. Little is known, however, about which interventions have been evaluated for nurses and midwives. Our review is a critical first step to building the evidence-base for healthcare organisations seeking to address this important operational issue.

OBJECTIVES

We address two questions: (1) what sleep-related/fatigue-management interventions have been assessed in nurses and midwives and what is their evidence-base? and (2) what measures are used by researchers to assess intervention effectiveness?

DESIGN AND DATA SOURCES

The following databases were searched in November, 2018 with no limit on publication dates: MEDLINE, PsychINFO and CINAHL.

REVIEW METHODS

We included: (1) studies conducted in adult samples of nurses and/or midwives that had evaluated a sleep-related/fatigue-management intervention; and (2) studies that reported intervention effects on fatigue, sleep, or performance at work, and on measures of attention or cognitive performance (as they relate to the impact of shift working on patient safety/care).

RESULTS

The search identified 798 potentially relevant articles, out of which 32 met our inclusion criteria. There were 8619 participants across the included studies and all were nurses (88.6% female). We did not find any studies conducted in midwives nor any studies conducted in the UK, with most studies conducted in the US, Italy and Taiwan. There was heterogeneity both in terms of the interventions evaluated and the measures used to assess effectiveness. Napping could be beneficial but there was wide variation regarding nap duration and timing, and we need to understand more about barriers to implementation. Longer shifts, shift patterns including nights, and inadequate recovery time between shifts (quick returns) were associated with poorer sleep, increased sleepiness and increased levels of fatigue. Light exposure and/or light attenuation interventions showed promise but the literature was dominated by small, potentially unrepresentative samples.

CONCLUSIONS

The literature related to sleep-related/fatigue-management interventions for nurses and midwives is fragmented and lacks cohesion. Further empirical work is warranted with a view to developing comprehensive Fatigue Risk Management Systems to protect against fatigue in nurses, midwives, and other shift working healthcare staff.

Napping and cognitive performance during night shifts: a systematic review and meta-analysis

Study Objectives

To examine the benefits of napping during night shifts on cognitive performance.

Methods

Medline, Cochrane Library, Science direct, and Embase databases were searched up to July 1, 2019. Cognitive performance during night shifts, both before and following napping or under control conditions (no nap), in working-aged adults, were analyzed by time and by type of cognitive function (executive function, attention, instrumental function, and memory). Estimates were pooled using random-effects meta-analysis.

Results

A total of 18 articles (6 in real-work and 12 in laboratory) with a total of 494 participants were included. The mean nap duration was 41.6 ± 28.3 min, occurring between 12.00 am and 4.10 am, with a mean time set at 2.12 am. Cognitive performance did not differ at baseline between the groups (effect size 0.02, 95% CI −0.09 to 0.13). There was an overall improvement in performance following a nap compared to the control condition without a nap (0.25, 0.10 to 0.41). Positioning naps early in the night and activity (simulated work tasks) tended to improve cognitive performance (−0.57, −1.16 to 0.002, and 0.082, −0.04 to 0.33, respectively). The improvements were primarily seen 30 min after awakening. Only memory deteriorated immediately after awakening without an overall change in global cognitive performance.

Conclusion

Napping during night shifts seems to improve cognitive performance. Napping early in the night and activity may benefit cognitive performance over time. Considering lack of data in real work environments, further studies are warranted before preconizing napping during night shifts as a preventive strategy (safety, health, and economic outcomes).

Improving fatigue risk management in healthcare: A systematic scoping review of sleep-related/fatigue-management interventions for nurses and midwives

BACKGROUND

Nurses and midwives make up almost 50% of the global healthcare shift working workforce. Shift work interferes with sleep and causes fatigue with adverse effects for nurses' and midwives' health, as well as on patient safety and care. Where other safety-critical sectors have developed Fatigue Risk Management Systems, healthcare is behind the curve; with published literature only focussing on the evaluation of discreet sleep-related/fatigue-management interventions. Little is known, however, about which interventions have been evaluated for nurses and midwives. Our review is a critical first step to building the evidence-base for healthcare organisations seeking to address this important operational issue.

OBJECTIVES

We address two questions: (1) what sleep-related/fatigue-management interventions have been assessed in nurses and midwives and what is their evidence-base? and (2) what measures are used by researchers to assess intervention effectiveness?

DESIGN AND DATA SOURCES

The following databases were searched in November, 2018 with no limit on publication dates: MEDLINE, PsychINFO and CINAHL.

REVIEW METHODS

We included: (1) studies conducted in adult samples of nurses and/or midwives that had evaluated a sleep-related/fatigue-management intervention; and (2) studies that reported intervention effects on fatigue, sleep, or performance at work, and on measures of attention or cognitive performance (as they relate to the impact of shift working on patient safety/care).

RESULTS

The search identified 798 potentially relevant articles, out of which 32 met our inclusion criteria. There were 8619 participants across the included studies and all were nurses (88.6% female). We did not find any studies conducted in midwives nor any studies conducted in the UK, with most studies conducted in the US, Italy and Taiwan. There was heterogeneity both in terms of the interventions evaluated and the measures used to assess effectiveness. Napping could be beneficial but there was wide variation regarding nap duration and timing, and we need to understand more about barriers to implementation. Longer shifts, shift patterns including nights, and inadequate recovery time between shifts (quick returns) were associated with poorer sleep, increased sleepiness and increased levels of fatigue. Light exposure and/or light attenuation interventions showed promise but the literature was dominated by small, potentially unrepresentative samples.

CONCLUSIONS

The literature related to sleep-related/fatigue-management interventions for nurses and midwives is fragmented and lacks cohesion. Further empirical work is warranted with a view to developing comprehensive Fatigue Risk Management Systems to protect against fatigue in nurses, midwives, and other shift working healthcare staff.

Sleep problems in shift nurses: A brief review and recommendations at both individual and institutional levels

AIMS

The purposes of this article are (a) to review briefly the current literature on shift nurses' sleep patterns, sleep quality, and the existing interventions implemented in nursing settings; and (b) to propose solutions that target individual nurses, nurse managers, and health care organisations to improve sleep health in shift nurses.

BACKGROUND

Sleep problems among shift nurses have been recognized increasingly as a significant issue at both the individual and organisational levels. However, the solutions are not well known.

DESIGN

Narrative review.

METHODS

A literature search was conducted using the following databases: CINAHL, PubMed, Embase, and Google Scholar from 1986 to 2016, to include original papers that reported studies on shift nurses' sleep problems and interventions.

RESULTS

Thirteen papers were included in this review, which all indicated associations between shift nurses' sleep problems and current intervention practices. Despite the higher prevalence of sleep problems in shift nurses compared to the general population, current interventional practices only focus on bright-light exposure, nap breaks, shift schedule rearrangement, and behavioural interventions.

CONCLUSIONS

To address shift nurses' poor sleep quality, we proposed two levels of approach for consideration-the individual level and the management/institutional level. The recommendations include: improving sleep hygiene; providing a low-stimulation sleep environment; conducting rigorous intervention studies to evaluate the effectiveness of a variety of therapies to deal with shift nurses' sleep disturbances; increasing awareness of sleep health of shift nurses; establishing a flexible rotating work schedule; and putting in place policies such as a 15-30 min nap break, social support, and a suitable working environment.

IMPLICATIONS FOR NURSING MANAGEMENT

With better awareness and understanding of shift nurses' sleep behaviours, effective interventions can be employed to improve shift nurses' sleep patterns and sleep quality to promote better emotional and health outcomes.

Effects of Napping During Shift Work on Sleepiness and Performance in Emergency Medical Services Personnel and Similar Shift Workers: A Systematic Review and Meta-Analysis

BACKGROUND

Scheduled napping during work shifts may be an effective way to mitigate fatigue-related risk. This study aimed to critically review and synthesize existing literature on the impact of scheduled naps on fatigue-related outcomes for EMS personnel and similar shift worker groups.

METHODS

A systematic literature review was performed of the impact of a scheduled nap during shift work on EMS personnel or similar shift workers. The primary (critical) outcome of interest was EMS personnel safety. Secondary (important) outcomes were patient safety; personnel performance; acute states of fatigue, alertness, and sleepiness; indicators of sleep duration and/or quality; employee retention/turnover; indicators of long-term health; and cost to the system. Meta-analyses were performed to evaluate the impact of napping on a measure of personnel performance (the psychomotor vigilance test [PVT]) and measures of acute fatigue.

RESULTS

Of 4,660 unique records identified, 13 experimental studies were determined relevant and summarized. The effect of napping on reaction time measured at the end of shift was small and non-significant (SMD 0.12, 95% CI -0.13 to 0.36; p = 0.34). Napping during work did not change reaction time from the beginning to the end of the shift (SMD -0.01, 95% CI -25.0 to 0.24; p = 0.96). Naps had a moderate, significant effect on sleepiness measured at the end of shift (SMD 0.40, 95% CI 0.09 to 0.72; p = 0.01). The difference in sleepiness from the start to the end of shift was moderate and statistically significant (SMD 0.41, 95% CI 0.09 to 0.72; p = 0.01).

CONCLUSIONS

Reviewed literature indicated that scheduled naps at work improved performance and decreased fatigue in shift workers. Further research is required to identify the optimal timing and duration of scheduled naps to maximize the beneficial outcomes.

Four Night Shifts Have a Degree of Performance Adaptation

OBJECTIVE

In this case control study, we investigated the process of adaptation to night shift (NS) work and recovery back to a day schedule among nurses working a fast-rotation three-shift schedule.

BACKGROUND

There is limited knowledge of how specific patterns of a fast-rotation shift affect nurses' performance.

METHOD

The cognitive performance of off-duty nurses (OD; n = 21), those working the first night of an NS (1NS; n = 21) and the last night of two ( n = 21), three ( n = 20), and four (4NS; n = 21) successive NSs were compared. Changes in sleep propensity, cognitive function, and anxiety were compared in the daytime after working four successive NSs followed by 24 hr off (4NS-off; n = 18) and in those off duty.

RESULTS

The visual attention task (VAT) of cognitive function was significantly worse in the 1NS group and significantly better on the last night in the 4NS group than in the other NS groups. The nurses in the 4NS-off group were less alert and had poorer VAT performance than the OD group during the daytime.

CONCLUSION

The nurses working on NS experienced a decrease in VAT performance due to acute changes in circadian rhythm but also significant performance adaptation after four consecutive NSs. One off-duty day was insufficient to recover back to a daytime shift after four consecutive NSs.

APPLICATION

In a fast-rotation three-shift schedule, performance adaptation occurred in the nurses who worked four consecutive NSs, and more than one off-duty day are needed to recover back to daytime shift after those NSs.

Antecedents and outcomes of nurses' rest break organization: A scoping review

OBJECTIVES

To prevent an accumulation of strain during work and to reduce error risk, many countries have made rest breaks mandatory. In the nursing literature, insufficient rest break organization is often reported. However, the outcomes of nurses' rest break organization and its anteceding factors are less clear.

DATA SOURCES

We searched for academic literature on nurses' rest break organization in electronic databases (PubMed, Medline, PsycArticles, PsycINFO, CINAHL).

REVIEW METHODS

Our search yielded 93 potentially relevant articles published between 01/1990 and 04/2016. The final sample in our scoping review consisted of 36 publications and included data from 35 independent and international study samples and two reviews.

RESULTS

Several studies reported a high prevalence of missed, interrupted, or delayed rest breaks in nursing. Nurses' rest breaks often related to better physical and mental well-being but did not affect motivational outcomes and performance systematically. Results on the effects of napping breaks were inconsistent. Rest break activities and high quality rest break areas are further factors that relieve nurses from job demands and can be helpful in coping with them. Several study results indicated that temporal and quantitative work demands, job resources, and individual characteristics influence rest break organization. However, most of these findings stem from studies that do not allow causal conclusions to be drawn.

CONCLUSIONS

Well-designed rest breaks influence nurses' occupational well-being and behavior positively. However, the mechanisms and moderating break-, work-, and person-related factors involved in producing these effects are not well understood today. Thus, further theory building and stronger empirical data are needed.

Napping: A public health issue. From epidemiological to laboratory studies

Sleep specialists have proposed measures to counteract the negative short- and long-term consequences of sleep debt, and some have suggested the nap as a potential and powerful "public health tool". Here, we address this countermeasure aspect of napping viewed as an action against sleep deprivation rather than an action associated with poor health. We review the physiological functions that have been associated positively with napping in both public health and clinical settings (sleep-related accidents, work and school, and cardiovascular risk) and in laboratory-based studies with potential public health issues (cognitive performance, stress, immune function and pain sensitivity). We also discuss the circumstances in which napping-depending on several factors, including nap duration, frequency, and age-could be a potential public health tool and a countermeasure for sleep loss in terms of reducing accidents and cardiovascular events and improving sleep-restriction-sensitive working performance. However, the impact of napping and the nature of the sleep stage(s) involved still need to be evaluated, especially from the perspective of coping strategies in populations with chronic sleep debt, such as night and shift workers.

Person-directed, non-pharmacological interventions for sleepiness at work and sleep disturbances caused by shift work

BACKGROUND

Shift work is often associated with sleepiness and sleep disorders. Person-directed, non-pharmacological interventions may positively influence the impact of shift work on sleep, thereby improving workers' well-being, safety, and health.

OBJECTIVES

To assess the effects of person-directed, non-pharmacological interventions for reducing sleepiness at work and improving the length and quality of sleep between shifts for shift workers.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid, Embase, Web of Knowledge, ProQuest, PsycINFO, OpenGrey, and OSH-UPDATE from inception to August 2015. We also screened reference lists and conference proceedings and searched the World Health Organization (WHO) Trial register. We contacted experts to obtain unpublished data.

SELECTION CRITERIA

Randomised controlled trials (RCTs) (including cross-over designs) that investigated the effect of any person-directed, non-pharmacological intervention on sleepiness on-shift or sleep length and sleep quality off-shift in shift workers who also work nights.

DATA COLLECTION AND ANALYSIS

At least two authors screened titles and abstracts for relevant studies, extracted data, and assessed risk of bias. We contacted authors to obtain missing information. We conducted meta-analyses when pooling of studies was possible.

MAIN RESULTS

We included 17 relevant trials (with 556 review-relevant participants) which we categorised into three types of interventions: (1) various exposures to bright light (n = 10); (2) various opportunities for napping (n = 4); and (3) other interventions, such as physical exercise or sleep education (n = 3). In most instances, the studies were too heterogeneous to pool. Most of the comparisons yielded low to very low quality evidence. Only one comparison provided moderate quality evidence. Overall, the included studies' results were inconclusive. We present the results regarding sleepiness below. Bright light Combining two comparable studies (with 184 participants altogether) that investigated the effect of bright light during the night on sleepiness during a shift, revealed a mean reduction 0.83 score points of sleepiness (measured via the Stanford Sleepiness Scale (SSS) (95% confidence interval (CI) -1.3 to -0.36, very low quality evidence). Another trial did not find a significant difference in overall sleepiness on another sleepiness scale (16 participants, low quality evidence).Bright light during the night plus sunglasses at dawn did not significantly influence sleepiness compared to normal light (1 study, 17 participants, assessment via reaction time, very low quality evidence).Bright light during the day shift did not significantly reduce sleepiness during the day compared to normal light (1 trial, 61 participants, subjective assessment, low quality evidence) or compared to normal light plus placebo capsule (1 trial, 12 participants, assessment via reaction time, very low quality evidence). Napping during the night shiftA meta-analysis on a single nap opportunity and the effect on the mean reaction time as a surrogate for sleepiness, resulted in a 11.87 ms reduction (95% CI 31.94 to -8.2, very low quality evidence). Two other studies also reported statistically non-significant decreases in reaction time (1 study seven participants; 1 study 49 participants, very low quality evidence).A two-nap opportunity resulted in a statistically non-significant increase of sleepiness (subjective assessment) in one study (mean difference (MD) 2.32, 95% CI -24.74 to 29.38, 1 study, 15 participants, low quality evidence). Other interventionsPhysical exercise and sleep education interventions showed promise, but sufficient data to draw conclusions are lacking.

AUTHORS' CONCLUSIONS

Given the methodological diversity of the included studies, in terms of interventions, settings, and assessment tools, their limited reporting and the very low to low quality of the evidence they present, it is not possible to determine whether shift workers' sleepiness can be reduced or if their sleep length or quality can be improved with these interventions.We need better and adequately powered RCTs of the effect of bright light, and naps, either on their own or together and other non-pharmacological interventions that also consider shift workers' chronobiology on the investigated sleep parameters.