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Zhang Y, Murphy A, Lammers-van der Holst HM, Barger LK, Duffy JF. Night Shift Work and Sleep Experiences in Older Night Shift Nurses. West J Nurs Res 2024:1939459241299779. [PMID: 39535119 DOI: 10.1177/01939459241299779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2024]
Abstract
BACKGROUND Working at night leads to misalignment between the biological clock and the work/sleep schedule, resulting in sleepiness and impaired performance during the night shift and poor quality, shortened sleep during the day; this is greatly impaired in older individuals. OBJECTIVE To describe night work and sleep experiences from the perspective of older (aged 50-65) nurses. METHODS Seven virtual focus groups were formed comprising 19 older nurses who worked regular 8-hour night shifts (at least 6 consecutive hours between midnight and 6 am) to learn about their shift work and sleep experiences. Two facilitators and 2 research assistants independently reviewed and coded the transcripts using qualitative content analysis. RESULTS Nine themes were identified in 3 domains: (a) night shift challenges and difficulties, including first night shift is most difficult; never feel rested working nights; and personal health concerns and benefits from working nights; (b) sleep challenges and difficulties, including inconsistent sleep timing when switching between nights and days; extended (24+ hours) time awake before and after consecutive nights; difficulty maintaining long and sound daytime sleep; and napping before night shifts for better performance; and (c) family and social challenges and support, including childcare, family, personal obligations, and social activities affect sleep; aging of self and children influences sleep and prioritization of sleep. CONCLUSIONS The findings help understand challenges and struggles to obtain adequate sleep and safe work performance in older night shift nurses. These insignts are critical for designing and implementing feasible and acceptable interventions to improve sleep in this high-risk occupational group.
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Affiliation(s)
- Yuan Zhang
- Zuckerberg College of Health Sciences, Solomont School of Nursing, University of Massachusetts Lowell, Lowell, MA, USA
| | - Audra Murphy
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Laura K Barger
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Jeanne F Duffy
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
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Harris R, Drummond SPA, Meadley B, Rajaratnam SMW, Williams B, Smith K, Bowles KA, Nguyen E, Dobbie ML, Wolkow AP. Adaptive sleep behaviours and shift work tolerance during the transition to shift work. Sleep Med 2024; 124:483-493. [PMID: 39432982 DOI: 10.1016/j.sleep.2024.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 09/18/2024] [Accepted: 10/03/2024] [Indexed: 10/23/2024]
Abstract
OBJECTIVE To evaluate whether recruit paramedics adapt their sleep behaviour during the first 12-months of shift work and to identify sleep behaviours that are associated with better shift work tolerance (SWT) after 12-months of shift work. METHODS Recruit paramedics (n = 105; Mage = 25.81 years; 51.38% female) were evaluated before (baseline), and after six- and 12-months of shift work. At each timepoint, participants completed questionnaires evaluating their mental health and sleep. Participants also underwent 14 days of sleep and shift monitoring (sleep/work diaries and actigraphy) at each timepoint to examine sleep behaviours, including sleep opportunity (SO), sleep regularity and number of sleep episodes. RESULTS Linear mixed models found SO increased (on day shifts and rest days), and sleep regularity decreased between baseline and follow-up timepoints. There were no changes in SO (on day shifts, nightshifts, and rest days) or sleep regularity between six- and 12-months of shift work. Latent profile analysis at 12-months follow-up identified high (n = 52), medium (n = 27), and low (n = 9) SWT levels (measured via depression, anxiety, insomnia, sleep quality and sleep efficiency) in paramedics. Reduced sleep regularity (i.e., more irregular sleep) between six- and 12-months of work and prioritising major sleep (rather than naps) at six-months predicted high SWT. CONCLUSIONS These findings suggest clear SWT levels exist early in paramedics' careers whereby symptoms of depression, anxiety, and insomnia were the strongest contributors to SWT. New paramedics' sleep behaviours, including sleep regularity and prioritisation of longer sleep between nightshifts, may play an important role in influencing how paramedics tolerate shift work.
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Affiliation(s)
- Rachael Harris
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, 3800, Australia
| | - Sean P A Drummond
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, 3800, Australia
| | - Ben Meadley
- Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia; Department of Paramedicine, Monash University, Frankston, Victoria, 3199, Australia; Ambulance Victoria, Doncaster, Victoria, 3108, Australia
| | - Shantha M W Rajaratnam
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, 3800, Australia; Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia
| | - Brett Williams
- Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia; Department of Paramedicine, Monash University, Frankston, Victoria, 3199, Australia; Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Jordan
| | - Karen Smith
- Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia; Department of Paramedicine, Monash University, Frankston, Victoria, 3199, Australia; Department of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, 3000, Australia; Research and Innovation, Silverchain Group, Melbourne, Victoria, Australia
| | - Kelly-Ann Bowles
- Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia; Department of Paramedicine, Monash University, Frankston, Victoria, 3199, Australia
| | - Elle Nguyen
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, 3800, Australia
| | - Megan L Dobbie
- Ambulance Victoria, Doncaster, Victoria, 3108, Australia
| | - Alexander P Wolkow
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, 3800, Australia; Paramedic Health and Wellbeing Research Unit, Monash University, Frankston, Victoria, 3199, Australia.
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Elliott J, Hodges C, Boots M, Pattinson R, Gillen E, Whybrow D, Bundy C. Mixed shift rotations, sleep, burnout and well-being in professions similar to radiographers: A systematic review. Radiography (Lond) 2024; 30:1194-1200. [PMID: 38901073 DOI: 10.1016/j.radi.2024.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/23/2024] [Accepted: 05/30/2024] [Indexed: 06/22/2024]
Abstract
INTRODUCTION Delivering 24 h healthcare requires rotational shift work from doctors and the medical imaging team, while contributing to safe and timely care of patients. Additional service pressure and staff shortfall leads to workload pressures, adjusted shift patterns and risk of burnout. Evidence should be sought to the effects of this work on staff. METHODS This systematic review followed PRISMA reporting guidelines, using a convergent mixed methods approach according to Guidance from Joanna Briggs International. Quantitative trends and results were qualified in order to thematically analyse in conjunction with qualitative data and discussed together in context. Following initial searching, returned articles were screened by title and abstract. A team of 3 reviewers undertook blinded critical appraisal of those suitable, with quality assurance from a 4th team member. Papers passing a threshold of 75% on JBI appraisal tools were accepted for synthesis. Data extraction of appropriate articles retrieved was undertaken in parallel. RESULTS Following screening and critical appraisal, 13 studies were returned focusing exclusively on Non Consultant Doctors. No studies investigated diagnostic radiographers. 85% (n = 11) reported negative association between shift work and the three themes of sleep/fatigue, burnout and wellbeing: including after the introduction of shift pattern control or adjusted shift patterns. The remainder showed no change, or any improvement nullified by countermeasures to maintain service delivery. CONCLUSION Current working practices and shift plans in the target population showed detrimental effects on the participants - this can be suggested that Diagnostic Radiographers may suffer fatigue, burnout and poor mental health from stretched shift working patterns. IMPLICATIONS FOR PRACTICE Further study into the effects of shift work on Diagnostic Radiographers and other allied health professionals is indicated - relating to the above themes in the context of errors and patient safety. Additional research into Non Consultant Doctors, shift work effects and the context of wider service delivery required; with suitable interventions and education to maximise understanding of legal working practices, monitoring and self-management of symptoms.
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Lammers-van der Holst HM, Qadri S, Murphy A, Ronda JM, Zhang Y, Barger LK, Duffy JF. Evaluation of sleep strategies between night shifts in actual shift workers. Sleep Health 2024; 10:S108-S111. [PMID: 37940478 PMCID: PMC11031311 DOI: 10.1016/j.sleh.2023.08.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/31/2023] [Accepted: 08/31/2023] [Indexed: 11/10/2023]
Abstract
OBJECTIVES The aim of this observational study was to examine sleep obtained between consecutive night shifts from shift workers in their natural environment. The goal was to identify the various sleep strategies and the timing, duration, regularity, and quality of sleep associated with the strategies. METHODS Participants (N = 33, 23 women, aged 40 ± 15years) reported their sleep information in daily diaries over 2weeks while working at least one series of consecutive night shifts. Sleep timing, duration, quality, and regularity were calculated for each sleep episode between consecutive night shifts. RESULTS Based on the reported sleep behavior, shift workers were categorized as either morning, delayed, split- or mixed sleepers. We found significant differences between the groups in timing of sleep, feeling refreshed, and regularity of sleep between consecutive night shifts, whereas duration and subjective soundness of sleep did not show significant differences. CONCLUSIONS In this sample, four sleep strategies were observed between consecutive night shifts in actual shift workers. These observations may help design future interventions to improve sleep that are individualized to the worker.
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Affiliation(s)
| | - Salim Qadri
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Audra Murphy
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Joseph M Ronda
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Yuan Zhang
- Solomont School of Nursing, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Laura K Barger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeanne F Duffy
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
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Bessman SC, Harrison EM, Easterling AP, Snider MN, Preilipper SMM, Glickman GL. Hybrid effectiveness-implementation study of two novel spectrally engineered lighting interventions for shiftworkers on a high-security watchfloor. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2023; 4:zpad051. [PMID: 38084298 PMCID: PMC10710545 DOI: 10.1093/sleepadvances/zpad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/13/2023] [Indexed: 06/26/2024]
Abstract
Shiftwork leads to myriad negative health and safety outcomes. Lighting countermeasures can benefit shiftworkers via physiological effects of light (e.g. alerting, circadian adjustment), and short-wavelength light is the most potent for eliciting those responses; however, limited work indicates it may not be required for alerting. We developed similar-appearing light boxes (correlated color temperature: 3000-3375 K; photopic illuminance: 260-296 lux), enriched (SW+, melanopic EDI: 294 lux) or attenuated (SW-, melanopic EDI: 103 lux) in short-wavelength energy, and implemented them on a high-security watchfloor. Efficacy and feasibility of these two novel lighting interventions were assessed in personnel working 12-hour night shifts (n = 47) in this within-participants, crossover study. For each intervention condition, light boxes were arranged across the front of the watchfloor and illuminated the entire shift; blue-blocking glasses were worn post-shift and before sleep; and sleep masks were used while sleeping. Comparisons between baseline and intervention conditions included alertness, sleep, mood, quality of life (QOL), and implementation measures. On-shift alertness (Karolinska Sleepiness Scale) increased in SW- compared to baseline, while changes in SW+ were more limited. Under SW+, both mood and sleep improved. Psychomotor vigilance task performance did not vary by condition; however, perceived performance and QOL were higher, and reported caffeine consumption and sleep onset latency were lower, under SW-. For both interventions, satisfaction and comfort were high, and fewer symptoms and negative feelings were reported. The addition of spectrally engineered lights to this unique work environment improved sleep, alertness, and mood without compromising visual comfort and satisfaction. This paper is part of the Sleep and Circadian Rhythms: Management of Fatigue in Occupational Settings Collection.
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Affiliation(s)
- Sara C Bessman
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Elizabeth M Harrison
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Alexandra P Easterling
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Michelle N Snider
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Sebastian M M Preilipper
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Gena L Glickman
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
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Circadian, light, and sleep skills program: Efficacy of a brief educational intervention for improving sleep and psychological health at sea. Sleep Health 2022; 8:542-550. [PMID: 35872149 DOI: 10.1016/j.sleh.2022.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/24/2022] [Accepted: 05/29/2022] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Military service poses unique threats to sleep and circadian health, and the shipboard environment presents further challenges. Disrupted sleep and circadian rhythms are linked to myriad health and safety issues that compromise readiness, including negative psychological health outcomes. Thus, one advantage of mitigating sleep problems includes the possibility of also enhancing mental health. PROCEDURES We evaluated the efficacy of the Circadian, Light, and Sleep Skills program for shipboard military personnel for improving sleep, and examined the impact of sleep on mental health in participating sailors. Questionnaires were administered to US sailors (N = 150) assigned to three ships (one control, two intervention) before the program (T1), immediately afterward (T2), and 2-4 months later, after a period at sea (T3). Outcomes included motivation to improve sleep; sleep and circadian knowledge; frequency of sleep-promoting behaviors; sleep quality (Pittsburgh Sleep Quality Index); and mental health symptoms. Satisfaction with specific program elements and perceived relevance were also examined. MAIN FINDINGS Sleep and circadian knowledge, frequency of sleep-promoting behaviors, and sleep quality improved from T1 to T3 in the intervention versus control group. Sleep quality also mediated the effects of the underway (at sea) period on mental health. The intervention was well received, with high satisfaction and perceived relevance ratings. PRINCIPAL CONCLUSIONS A brief 30-min intervention before an underway period improved sleep, circadian, and psychological health outcomes in shipboard sailors, even months later. Broader dissemination of this program may provide significant positive impact with minimal investment of resources.
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The Development, Implementation, and Feasibility of a Circadian, Light, and Sleep Skills Program for Shipboard Military Personnel (CLASS-SM). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19053093. [PMID: 35270786 PMCID: PMC8910671 DOI: 10.3390/ijerph19053093] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/23/2022] [Accepted: 03/04/2022] [Indexed: 12/10/2022]
Abstract
Service members face unique barriers to sufficient and high quality sleep. In the present study, a circadian, light, and sleep skills program for shipboard military personnel (CLASS-SM) was designed to encourage and inform strategies that support optimal sleep and circadian health in the context of those barriers. Phase 1 included program development and refinement via an iterative formative evaluation, including structured interviews with service members and feedback from veterans and experts, resulting in further tailoring to the population. In Phase 2, the highly tailored program was administered to shipboard personnel (n = 55), and acceptability indicators were measured. Sleep- and circadian-related knowledge (pre- and post-program) and the perceived relevance of, and satisfaction with, program content (post-program) were assessed. Before the intervention, most individuals were unaware that 7−9 h of sleep is recommended (72%) and had little understanding of the physiological effects of light; however, knowledge scores increased significantly post-program, from 51% to 88% correct (p < 0.0001). Reception was positive, with high reported satisfaction and relevance. Most individuals reported that they learned something new (89%), planned to use one or more learned strategies (100%), and intended to share learned information with others (85%); the physiological effects of light and circadian rhythms were the content areas most frequently reported as new and useful. The results demonstrate the need for, and feasibility of, the delivery of this program in operational environments.
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Casjens S, Brenscheidt F, Tisch A, Beermann B, Brüning T, Behrens T, Rabstein S. Social jetlag and sleep debts are altered in different rosters of night shift work. PLoS One 2022; 17:e0262049. [PMID: 34995309 PMCID: PMC8740972 DOI: 10.1371/journal.pone.0262049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/15/2021] [Indexed: 12/17/2022] Open
Abstract
Background Night and shift work are suspected to cause various adverse effects on health and sleep. Sleep deprivation through shift work is assumed to be compensated on free days. So far it is not clear how different shift systems and shift lengths affect sleep structure on work and free days. Especially working night shifts disrupts the circadian rhythm but also extended working hours (12h) might affect sleep characteristics. Hitherto, the magnitude of sleep debt, social jetlag, and Locomotor Inactivity During Sleep (LIDS) in different shift systems is unknown. Methods Here, we investigated the impact of five different shift rosters on sleep in 129 industrial workers from Germany. Permanent night work with multiple shift systems with and without night shifts and with different shift lengths were compared. Wrist-activity was monitored over 28 days revealing sleep on- and offsets as well as LIDS as proxy for sleep quality. Overall, 3,865 sleep bouts comprising 22,310 hours of sleep were examined. Results The mean daily age-adjusted sleep duration (including naps) was 6:43h and did not differ between shift workers of different rosters. However, sleep duration on workdays was particularly low in rotational shift systems with 12h-shifts (5:00h), while overall sleep debt was highest. Shift workers showed a median absolute social jetlag of 3:03h, which differed considerably between shift types and rosters (p<0.0001). Permanent night workers had the highest social jetlag (5:08h) and latest mid-sleeps on workdays and free days. Sleep quality was reduced in permanent night shift workers compared with shift workers in other rosters and differed between daytime and nighttime sleep. Conclusions Shift work leads to partial sleep deprivation, which particularly affects workers in 12h-shifts and permanent night shifts. Working these shifts resulted in higher sleep debts and larger absolute social jetlag whereas sleep quality was especially reduced in permanent night shift workers compared with shift workers of other rosters.
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Affiliation(s)
- Swaantje Casjens
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bochum, Germany
- * E-mail:
| | - Frank Brenscheidt
- Federal Institute for Occupational Safety and Health (BAuA), Dortmund, Germany
| | - Anita Tisch
- Federal Institute for Occupational Safety and Health (BAuA), Dortmund, Germany
| | - Beate Beermann
- Federal Institute for Occupational Safety and Health (BAuA), Dortmund, Germany
| | - Thomas Brüning
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bochum, Germany
| | - Thomas Behrens
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bochum, Germany
| | - Sylvia Rabstein
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr University Bochum (IPA), Bochum, Germany
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Sargent C, Kosmadopoulos A, Zhou X, Roach GD. Timing of Sleep in the Break Between Two Consecutive Night-Shifts: The Effect of Different Strategies on Daytime Sleep and Night-Time Neurobehavioural Function. Nat Sci Sleep 2022; 14:231-242. [PMID: 35210890 PMCID: PMC8860456 DOI: 10.2147/nss.s336795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/17/2021] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE The aim of this study was to examine whether the timing of sleep in the break between consecutive night-shifts affects the quantity and quality of sleep obtained during the daytime and/or neurobehavioural function and self-perceived capacity during the night-time. METHODS Participants (n = 12, all male, aged 22.9±5.2 y) completed three randomised, counterbalanced conditions in a sleep laboratory, consisting of two consecutive 12-hour night-shifts (18:00-06:00) with 7 hours in bed in the break between shifts. The three conditions differed only in the timing of the sleep opportunities - immediate (07:00-14:00), delayed (10:00-17:00), split (07:00-10:30 and 13:30-17:00). Neurobehavioural function (attention, memory, throughput) and self-perceived capacity (sleepiness, alertness, fatigue, mood) were assessed at 2-hour intervals during the night-shifts. RESULTS Condition did not affect total sleep time (p = 0.465), but it did affect sleep onset latency (p < 0.001; W = 0.780; large effect), wake after sleep onset (p = 0.018; W = 0.333; moderate effect) and the amount of Stage N3 sleep (p < 0.001; η2=0.510; small effect). Compared to the immediate and delayed sleep conditions, the split sleep condition had less wake after sleep onset and more Stage N3 sleep; and compared to the delayed condition, the split sleep condition had longer latency to sleep onset. There was no effect of condition on measures of neurobehavioural function or self-perceived capacity during the second night-shift. CONCLUSION None of the three sleep strategies examined here - immediate, delayed or split - are clearly superior or inferior to the others in terms of the capacity to sleep during the daytime or to work at night. Therefore, those who work consecutive night-shifts should employ the strategy that best suits their personal preferences and/or circumstances.
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Affiliation(s)
- Charli Sargent
- Appleton Institute for Behavioural Science, Central Queensland University, Wayville, SA, Australia
| | - Anastasi Kosmadopoulos
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Xuan Zhou
- Centre for Quantitative Genetics and Genomics, Aarhus University, Aarhus, Denmark
| | - Gregory D Roach
- Appleton Institute for Behavioural Science, Central Queensland University, Wayville, SA, Australia
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