The Nighttime Nap Strategies for Improving Night Shift Work in Workplace

Nagoya City University, Nagoya, Aichi, Japan
Industrial Health (Impact Factor: 1.12). 02/2005; 43(1):24-9. DOI: 10.2486/indhealth.43.24
Source: PubMed


Nighttime napping is an effective measure to prevent adverse effects due to night shift work. A characteristic of nighttime nap is that it can result in considerably deeper sleep. Several studies have shown that taking nighttime naps suppressed increasing sleepiness, decreasing alertness during the period following awaking from a nap, and prevented disturbance of circadian rhythm ("anchor sleep"). The length of daytime sleep after night shift, when combined with a nighttime nap, is shorter than that without nap. This finding might be interpreted as a beneficial effect rather than a negative feature because workers can then spend time engaged in other activities rather than sleeping. Nevertheless, the introduction of nighttime sleep break in the workplace has not been widely accepted. To promote nighttime napping strategy in the workplace, consensus building while acting on conflicting interest is essential. Recently, participatory method for improvement of working condition has expanded worldwide. A characteristic of the activity is using action checklist and group work, and heightening motivation to improvement working condition between worker and manager. Through the activities, nighttime napping strategy would be spread more in the workplaces and play a role as one of the effective tools for improving working conditions, work performance and safety in the future.

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    • "When the main sleep period is restricted or absent, adding supplementary naps improves alertness and performance (Bonnet, 1991; Dinges et al., 1987; Ficca et al., 2010; Sallinen et al., 1998; Takeyama et al., 2005). The term ''split sleep'' means two or more sleep opportunities in a 24-h period, ranging from a main sleep and a supplemental nap (e.g. 6 and 2 h), through a main sleep and several naps, to multiple naps with no clear main sleep (Belenky et al., 2008, 2011; Bonnet & Arand, 2003; Takeyama et al., 2005). Spilt sleep schedules are common practice in a number of industries including healthcare, maritime and transport. "
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    ABSTRACT: Shift work is common in today's society, and is associated with negative health outcomes, and accidents and incidents. These detrimental effects can be primarily attributed to sleeping and working at an adverse circadian time. The aim of this study was to examine whether a split sleep schedule is as effective as a consolidated day shift or night shift schedule for maintaining performance and sustaining sleep. Fifty-three healthy male volunteers (mean ± SD age ¼ 26.51 ± 4.07 years) underwent a randomized three condition study design. A split sleep condition involving two 5-h sleeping opportunities in 24 h [time in bed (TIB) 0300 h–0800 h and 1500 h–2000 h] was compared to a 10-h consolidated nighttime sleep (TIB 2200 h–0800 h) and 10-h consolidated daytime sleep (TIB 1000 h–2000 h). All participants underwent a baseline period of 10 h of nocturnal time in bed (TIB) followed by a 5-d simulated workweek spent in one of the three conditions. Polysomnography, psychomotor vigilance task, digit-symbol substitution task and subjective state were assessed. During the 5-d simulated workweek, participants in the nighttime sleep condition slept the most (total sleep time per day (TST) 8.4 h ± 13.4 min), followed by the split sleep condition (TST 7.16 h ± 14.2 min) and the daytime sleep condition (TST 6.4 h ± 15.3 min). Subjective sleepiness was highest in the daytime sleep condition and lowest in the nighttime sleep condition. No significant differences in performance were observed between the conditions. Compared to a nighttime consolidated sleep opportunity or split sleep, placement of a consolidated sleep opportunity during the day yielded truncated sleep and increased sleepiness. Further research in real-world situations is warranted to fully assess the efficacy of alternative split sleep schedules for improving safety and productivity.
    Chronobiology International 07/2014; in press(10). DOI:10.3109/07420528.2014.957305 · 3.34 Impact Factor
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    • "Because data for both shiftworkers and day workers were used in their analysis, they clearly showed the risk factors of SWD across the nurses with different work schedules. However, their study could not explore the association between SWD and the work-related factors specific to shiftworkers , such as the existence or absence of nighttime nap opportunities, which have been reported to be associated with shiftworkers' sleepiness during night work, wellbeing , and sleep-related problems such as excessive sleepiness (Purnell et al., 2002; Sallinen et al., 1998; Smith et al., 2007; Takeyama et al., 2005). "
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    ABSTRACT: Workers who meet the criteria for shift work disorder (SWD) have elevated levels of risk for various health and behavioral problems. However, the impact of having SWD on shiftworkers engaged in rapid-rotation schedules is unknown. Moreover, the risk factors for the occurrence of SWD remain unclear. To clarify these issues, we conducted a questionnaire-based, cross-sectional survey on a sample of shiftworking nurses. Responses were obtained from 1202 nurses working at university hospitals in Tokyo, Japan, including 727 two-shift workers and 315 three-shift workers. The questionnaire included items relevant to age, gender, family structure, work environment, health-related quality of life (QOL), diurnal type, depressive symptoms, and SWD. Participants who reported insomnia and/or excessive sleepiness for at least 1 mo that was subjectively relevant to their shiftwork schedules were categorized as having SWD. The prevalence of SWD in the sampled shiftworking nurses was 24.4%; shiftworking nurses with SWD showed lower health-related QOL and more severe depressive symptoms, with greater rates of both actual accidents/errors and near misses, than those without SWD. The results of logistic regression analyses showed that more time spent working at night, frequent missing of nap opportunities during night work, and having an eveningness-oriented chronotype were significantly associated with SWD. The present study indicated that SWD might be associated with reduced health-related QOL and decreased work performance in shiftworking nurses on rapid-rotation schedules. The results also suggested that missing napping opportunities during night work, long nighttime working hours, and the delay of circadian rhythms are associated with the occurrence of SWD among shiftworking nurses on rapid-rotation schedules. (Author correspondence: ).
    Chronobiology International 02/2013; 30(4). DOI:10.3109/07420528.2012.762010 · 3.34 Impact Factor
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    • "This peculiarity favours the holding of more than one job, which contributes to increasing the time spent working (Portela et al. 2005), with repercussions for workers' sleep and health (Fischer et al. 2006). As stated by Takeyama et al. (2005), there can be no doubt that the possibility of taking a nap is an effective tool for improving working conditions during night shifts. Concerning our data on recovery, not only the presence of sleep but also the amount of sleep has to be considered as sleeping for up to 2 hours was not related to a good recovery from work. "
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    ABSTRACT: This paper is a report of a study on the association between sleep patterns during work nights and recovery from work among nursing workers, considering domestic work hours. Several hospitals allow nursing workers to sleep during the night shift, but this is rarely evaluated from the workers' health perspective. The need for recovery from work concept can be useful for testing the impact of night work on sleep. Recovery is not a problem if workers have enough time to recover between periods of work. Therefore, domestic work would be likely to interfere in the recovery process. This cross-sectional study was carried out at three hospitals in 2005-2006, through a comprehensive questionnaire. All nursing teams engaged in assistance to patients were invited to participate. Analyses included female night workers with no incidence of insomnia. Participants (n = 396) were classified into those who did not sleep during night shifts, those who slept for up to 2 hours and those who slept for 2-3 hours. Binomial logistic regression analysis showed that sleeping on the job for 2-3 hours during night shifts is related to a better recovery from work provided the workers do not undergo long domestic work hours. Being allowed to sleep at work during night shifts seemed to contribute to, but was not enough to guarantee, a good recovery from work in the studied population. Recommendations to deal with sleep-deprivation among night workers should consider the complexity of gender roles on the recovery process.
    Journal of Advanced Nursing 05/2011; 67(5):972-81. DOI:10.1111/j.1365-2648.2010.05552.x · 1.74 Impact Factor
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