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Sunde E, Harris A, Olsen OK, Pallesen S. Moral decision-making at night and the impact of night work with blue-enriched white light or warm white light: a counterbalanced crossover study. Ann Med 2024; 56:2331054. [PMID: 38635448 PMCID: PMC11028009 DOI: 10.1080/07853890.2024.2331054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 02/24/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND Cognitive function, including moral decision-making abilities, can be impaired by sleep loss. Blue-enriched light interventions have been shown to ameliorate cognitive impairment during night work. This study investigated whether the quality of moral decision-making during simulated night work differed for night work in blue-enriched white light, compared to warm white light. METHODS Using a counterbalanced crossover design, three consecutive night shifts were performed in blue-enriched white light (7000 K) and warm white light (2500 K) provided by ceiling-mounted LED luminaires (photopic illuminance: ∼200 lx). At 03:30 h on the second shift (i.e. twice) and at daytime (rested), the Defining Issues Test-2, assessing the activation of cognitive schemas depicting different levels of cognitive moral development, was administered. Data from 30 (10 males, average age 23.3 ± 2.9 years) participants were analysed using linear mixed-effects models. RESULTS Activation of the post-conventional schema (P-score), that is, the most mature moral level, was significantly lower for night work in warm white light (EMM; estimated marginal mean = 44.3, 95% CI = 38.9-49.6; pholm=.007), but not blue-enriched white light (EMM = 47.5, 95% CI = 42.2-52.8), compared to daytime (EMM = 51.2, 95% CI = 45.9-56.5). Also, the P-score was reduced for night work overall (EMM = 45.9, 95% CI = 41.1-50.8; p=.008), that is, irrespective of light condition, compared to daytime. Neither activation of the maintaining norms schema (MN-score), that is, moderately developed moral level, nor activation of the personal interest schema (i.e. the lowest moral level) differed significantly between light conditions. The MN-score was however increased for night work overall (EMM = 26.8, 95% CI = 23.1-30.5; p=.033) compared to daytime (EMM = 23.1, 95% CI = 18.9-27.2). CONCLUSION The results indicate that moral decisions during simulated night work in warm white light, but not blue-enriched white light, become less mature and principle-oriented, and more rule-based compared to daytime, hence blue-enriched white light may function as a moderator. Further studies are needed, and the findings should be tentatively considered.Trial registration: ClinicalTrials.gov (ID: NCT03203538) Registered: 26/06/2017; https://clinicaltrials.gov/study/NCT03203538.
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Affiliation(s)
- Erlend Sunde
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Anette Harris
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Olav Kjellevold Olsen
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
- Department of Leadership and Organizational Behaviour, BI Norwegian Business School, Bergen, Norway
| | - Ståle Pallesen
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway
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Varma P, Postnova S, Knock S, Howard ME, Aidman E, Rajaratnam SWM, Sletten TL. SleepSync: Early Testing of a Personalised Sleep-Wake Management Smartphone Application for Improving Sleep and Cognitive Fitness in Defence Shift Workers. Clocks Sleep 2024; 6:267-280. [PMID: 38920420 PMCID: PMC11203003 DOI: 10.3390/clockssleep6020019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/27/2024] Open
Abstract
Shift work, long work hours, and operational tasks contribute to sleep and circadian disruption in defence personnel, with profound impacts on cognition. To address this, a digital technology, the SleepSync app, was designed for use in defence. A pre-post design study was undertaken to examine whether four weeks app use improved sleep and cognitive fitness (high performance neurocognition) in a cohort of shift workers from the Royal Australian Air Force. In total, 13 of approximately 20 shift-working personnel from one base volunteered for the study. Sleep outcomes were assessed using the Insomnia Severity Index (ISI), the Patient-Reported Outcomes Measurement Information System (PROMIS), Sleep Disturbance and Sleep-Related Impairment Scales, the Glasgow Sleep Effort Scale, the Sleep Hygiene Index, and mental health was assessed using the Depression, Anxiety, and Stress Scale-21. Sustained attention was measured using the 3-min Psychomotor Vigilance Task (PVT) and controlled response using the NBack. Results showed significant improvements in insomnia (ISI scores 10.31 at baseline and 7.50 after app use), sleep-related impairments (SRI T-scores 53.03 at baseline to 46.75 post-app use), and healthy sleep practices (SHI scores 21.61 at baseline to 18.83 post-app use; all p < 0.001). Trends for improvement were recorded for depression. NBack incorrect responses reduced significantly (9.36 at baseline; reduced by -3.87 at last week of app use, p < 0.001), but no other objective measures improved. These findings suggest that SleepSync may improve sleep and positively enhance cognitive fitness but warrants further investigation in large samples. Randomised control trials with other cohorts of defence personnel are needed to confirm the utility of this intervention in defence settings.
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Affiliation(s)
- Prerna Varma
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, VIC 3168, Australia
| | - Svetlana Postnova
- School of Physics, The University of Sydney, Camperdown, NSW 2050, Australia
| | - Stuart Knock
- School of Physics, The University of Sydney, Camperdown, NSW 2050, Australia
| | - Mark E. Howard
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, VIC 3168, Australia
- Institute for Breathing and Sleep, Austin Health, Heidelberg, VIC 3084, Australia
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Eugene Aidman
- Defence, Science and Technology Group, Department of Defence, Edinburgh, SA 5111, Australia;
- School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Shantha W. M. Rajaratnam
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, VIC 3168, Australia
- School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Tracey L. Sletten
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, VIC 3168, Australia
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Yook S, Choi SJ, Zang C, Joo EY, Kim H. Are there effects of light exposure on daytime sleep for rotating shift nurses after night shift?: an EEG power analysis. Front Neurosci 2024; 18:1306070. [PMID: 38601092 PMCID: PMC11004303 DOI: 10.3389/fnins.2024.1306070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/11/2024] [Indexed: 04/12/2024] Open
Abstract
Introduction Night-shift workers often face various health issues stemming from circadian rhythm shift and the consequent poor sleep quality. We aimed to study nurses working night shifts, evaluate the electroencephalogram (EEG) pattern of daytime sleep, and explore possible pattern changes due to ambient light exposure (30 lux) compared to dim conditions (<5 lux) during daytime sleep. Moethods The study involved 31 participants who worked night shifts and 24 healthy adults who had never worked night shifts. The sleep macro and microstructures were analyzed, and electrophysiological activity was compared (1) between nighttime sleep and daytime sleep with dim light and (2) between daytime sleep with dim and 30 lux light conditions. Results The daytime sleep group showed lower slow or delta wave power during non-rapid eye movement (NREM) sleep than the nighttime sleep group. During daytime sleep, lower sigma wave power in N2 sleep was observed under light exposure compared to no light exposure. Moreover, during daytime sleep, lower slow wave power in N3 sleep in the last cycle was observed under light exposure compared to no light exposure. Discussion Our study demonstrated that night shift work and subsequent circadian misalignment strongly affect sleep quality and decrease slow and delta wave activities in NREM sleep. We also observed that light exposure during daytime sleep could additionally decrease N2 sleep spindle activity and N3 waves in the last sleep cycle.
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Affiliation(s)
- Soonhyun Yook
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Su Jung Choi
- Graduate School of Clinical Nursing Science, Sungkyunkwan University, Seoul, Republic of Korea
| | - Cong Zang
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Eun Yeon Joo
- Department of Neurology, Neuroscience Center, Samsung Medical Center, Samsung Biomedical Research Institute, School of Medicine, Sungkyunkwan University, Seoul, Republic of Korea
| | - Hosung Kim
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
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Zimberg IZ, Ftouni S, Magee M, Ferguson SA, Lockley SW, Rajaratnam SMW, Sletten TL. Circadian adaptation to night shift work is associated with higher REM sleep duration. Sleep Health 2024; 10:S112-S120. [PMID: 37914630 DOI: 10.1016/j.sleh.2023.08.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 11/03/2023]
Abstract
OBJECTIVE To investigate the influence of the degree of circadian adaptation to night work on sleep architecture following night shift. METHODS Thirty four night workers (11 females; 33.8 ± 10.1years) completed a simulated night shift following 2-7 typical night shifts. Participants completed a laboratory-based simulated night shift (21:00-07:00 hours), followed by a recovery sleep opportunity (∼09:00-17:00 hours), recorded using polysomnography. Urinary 6-sulphatoxymelatonin (aMT6s) rhythm acrophase was used as a marker of circadian phase. Sleep duration and architecture were compared between individuals with aMT6s acrophase before (unadapted group, n = 22) or after (partially adapted group, n = 12) bedtime. RESULTS Bedtime occurred on average 2.16 hours before aMT6s acrophase in the partially adapted group and 3.91 hours after acrophase in the unadapted group. The partially adapted group had more sleep during the week before the simulated night than the unadapted group (6.47 ± 1.02 vs. 5.26 ± 1.48 hours, p = .02). After the simulated night shift, both groups had similar total sleep time (partially adapted: 6.68 ± 0.80 hours, unadapted: 6.63 ± 0.88 hours, p > .05). The partially adapted group had longer total rapid eye movement sleep duration than the unadapted group (106.79 ± 32.05 minutes vs. 77.90 ± 28.86 minutes, p = .01). After 5-hours, rapid eye movement sleep accumulation was higher in the partially adapted compared to the unadapted group (p = .02). Sleep latency and other stages were not affected by circadian adaptation. DISCUSSION Partial circadian adaptation to night shift was associated with longer rapid eye movement sleep duration during daytime sleep, highlighting the influence of entrainment between the sleep-wake cycle and the circadian pacemaker in night workers. The findings have important implications for sleep and subsequent alertness associated with shift work.
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Affiliation(s)
- Iona Z Zimberg
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Suzanne Ftouni
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michelle Magee
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, Goodwood, South Australia, Australia
| | - Steven W Lockley
- 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
| | - Shantha M W Rajaratnam
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia; 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
| | - Tracey L Sletten
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.
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Huang CH, Yu S, Yu HS, Tu HP, Yeh YT, Yu HS. Chronic blue light-emitting diode exposure harvests gut dysbiosis related to cholesterol dysregulation. Front Cell Infect Microbiol 2024; 13:1320713. [PMID: 38259967 PMCID: PMC10800827 DOI: 10.3389/fcimb.2023.1320713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
Night shift workers have been associated with circadian dysregulation and metabolic disorders, which are tightly coevolved with gut microbiota. The chronic impacts of light-emitting diode (LED) lighting at night on gut microbiota and serum lipids were investigated. Male C57BL/6 mice were exposed to blue or white LED lighting at Zeitgeber time 13.5-14 (ZT; ZT0 is the onset of "lights on" and ZT12 is the "lights off" onset under 12-hour light, 12-hour dark schedule). After 33 weeks, only the high irradiance (7.2 J/cm2) of blue LED light reduced the alpha diversity of gut microbiota. The high irradiance of white LED light and the low irradiance (3.6 J/cm2) of both lights did not change microbial alpha diversity. However, the low irradiance, but not the high one, of both blue and white LED illuminations significantly increased serum total cholesterol (TCHO), but not triglyceride (TG). There was no significant difference of microbial abundance between two lights. The ratio of beneficial to harmful bacteria decreased at a low irradiance but increased at a high irradiance of blue light. Notably, this ratio was negatively correlated with serum TCHO but positively correlated with bile acid biosynthesis pathway. Therefore, chronic blue LED lighting at a high irradiance may harvest gut dysbiosis in association with decreased alpha diversity and the ratio of beneficial to harmful bacteria to specifically dysregulates TCHO metabolism in mice. Night shift workers are recommended to be avoid of blue LED lighting for a long and lasting time.
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Affiliation(s)
- Cheng-Hsieh Huang
- Ph. D. Program in Environmental and Occupational Medicine, College of Medicine, Kaohsiung Medical University and National Health Research Institutes, Kaohsiung, Taiwan
- Aging and Disease Prevention Research Center, Fooyin University, Kaohsiung, Taiwan
| | - Sebastian Yu
- Department of Dermatology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsu-Sheng Yu
- Department of Food Science, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Hung-Pin Tu
- Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yao-Tsung Yeh
- Aging and Disease Prevention Research Center, Fooyin University, Kaohsiung, Taiwan
- Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan
| | - Hsin-Su Yu
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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6
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Hébert M, Lavigne AA, Auclair J, Martin JS, Francis K, Gagnon JD, Dubois MA, Laberge L. A Blue-Enriched Light Intervention Counteracts the Alertness Decrement Among Mine Workers on Extended 12-Hour Night Shift Periods. J Occup Environ Med 2023; 65:584-589. [PMID: 36962091 DOI: 10.1097/jom.0000000000002849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
OBJECTIVE The aim of the study is to assess whether a blue-enriched light intervention improves nocturnal alertness and daytime sleep of night workers. METHODS Thirteen miners performing 12-hour night shifts for 12 consecutive nights were exposed to a baseline and a blue-enriched light condition. All subjects wore an actigraph and completed a Psychomotor Vigilance Task at the beginning and at the end of each shift. Data were analyzed with linear mixed models. RESULTS In the blue-enriched light condition, the daily increase in median reaction time (RT), mean RT, slowest 10% of RT, and fastest 10% of RT was lower than that observed in the baseline condition between day 1 and 12 ( P ≤ 0.05). CONCLUSIONS The addition of blue-enriched light during a long period of extended night shifts counteracts most of the daily decline in nocturnal alertness observed in the standard lighting condition, irrespectively of sleep duration and sleep efficiency.
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Affiliation(s)
- Marc Hébert
- From the Centre de recherche CERVO, Centre Intégré Universitaire de Santé et des Services Sociaux de la Capitale Nationale, Québec, Canada (M.H., A.-A.L., J.-S.M., K.F., J.D.G., M.-A.D.); Département d'Ophtalmologie et d'Oto-Rhino-Laryngologie-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada (M.H., L.L.); ÉCOBES-Recherche et transfert, Cégep de Jonquière, Saguenay, Canada (J.A., L.L.); and Département de la santé, Université du Québec à Chicoutimi, Chicoutimi, Canada (L.L.)
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Murray JM, Magee M, Giliberto ES, Booker LA, Tucker AJ, Galaska B, Sibenaller SM, Baer SA, Postnova S, Sondag TA, Phillips AJ, Sletten TL, Howard ME, Rajaratnam SM. Mobile app for personalized sleep–wake management for shift workers: A user testing trial. Digit Health 2023; 9:20552076231165972. [PMID: 37009306 PMCID: PMC10064476 DOI: 10.1177/20552076231165972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 03/10/2023] [Indexed: 04/01/2023] Open
Abstract
Objective Development of personalized sleep–wake management tools is critical to improving sleep and functional outcomes for shift workers. The objective of the current study was to test the performance, engagement and usability of a mobile app ( SleepSync) for personalized sleep–wake management in shift workers that aid behavioural change and provide practical advice by providing personalized sleep scheduling recommendations and education. Methods Shift workers ( n = 27; 20 healthcare and 7 from other industries) trialled the mobile app for two weeks to determine performance, engagement and usability. Primary outcomes were self-reported total sleep time, ability to fall asleep, sleep quality and perception of overall recovery on days off. Secondary performance outcomes included sleep disturbances (insomnia and sleep hygiene symptoms, and sleep-related impairments) and mood (anxiety, stress and depression) pre- and post-app use. Satisfaction with schedule management, integration into daily routine and influence on behaviour were used to determine engagement, while the usability was assessed for functionality and ease of use of features. Results Total sleep time ( P = .04), ability to fall asleep ( P < .001), quality of sleep ( P = .001), insomnia ( P = .02), sleep hygiene ( P = .01), sleep-related impairments ( P = .001), anxiety ( P = .001), and stress ( P = .006) were all improved, with non-significant improvements in recovery on days off ( P = .19) and depression ( P = .07). All measures of engagement and usability were scored positively by the majority of users. Conclusions This pilot trial provides preliminary evidence of the positive impact of the SleepSync app in improving sleep and mood outcomes in shift workers, and warrants confirmation in a larger controlled trial.
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Affiliation(s)
- Jade M. Murray
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Michelle Magee
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Emma S. Giliberto
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Lauren A. Booker
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
- Institute for Breathing and Sleep, Austin Health, Heidelberg, Australia
| | - Andrew J. Tucker
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Beth Galaska
- Philips RS North America LLC f/k/a Respironics Inc, Murrysville, USA
| | | | - Sharon A. Baer
- Philips RS North America LLC f/k/a Respironics Inc, Murrysville, USA
| | - Svetlana Postnova
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
- School of Physics, University of Sydney, Sydney, Australia
| | | | - Andrew J.K. Phillips
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Tracey L. Sletten
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
| | - Mark E. Howard
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
- Institute for Breathing and Sleep, Austin Health, Heidelberg, Australia
| | - Shantha M.W. Rajaratnam
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, Australia
- Cooperative Research Centre for Alertness, Safety and Productivity, Clayton, Australia
- Shantha M.W. Rajaratnam, Turner Institute for Brain and Mental Health, School of Psychological Sciences, 18 Innovation Walk, Monash University, Clayton, Victoria 3800, Australia.
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Rahman SA, Kent BA, Grant LK, Clark T, Hanifin JP, Barger LK, Czeisler CA, Brainard GC, St Hilaire MA, Lockley SW. Effects of dynamic lighting on circadian phase, self-reported sleep and performance during a 45-day space analog mission with chronic variable sleep deficiency. J Pineal Res 2022; 73:e12826. [PMID: 35996978 DOI: 10.1111/jpi.12826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/29/2022] [Accepted: 08/20/2022] [Indexed: 10/15/2022]
Abstract
Spaceflight exposes crewmembers to circadian misalignment and sleep loss, which impair cognition and increase the risk of errors and accidents. We compared the effects of an experimental dynamic lighting schedule (DLS) with a standard static lighting schedule (SLS) on circadian phase, self-reported sleep and cognition during a 45-day simulated space mission. Sixteen participants (mean age [±SD] 37.4 ± 6.7 years; 5 F; n = 8/lighting condition) were studied in four-person teams at the NASA Human Exploration Research Analog. Participants were scheduled to sleep 8 h/night on two weekend nights, 5 h/night on five weekday nights, repeated for six 7-day cycles, with scheduled waketime fixed at 7:00 a.m. Compared to the SLS where illuminance and spectrum remained constant during wake (~4000K), DLS increased the illuminance and short-wavelength (blue) content of white light (~6000K) approximately threefold in the main workspace (Level 1), until 3 h before bedtime when illuminance was reduced by ~96% and the blue content also reduced throughout (~4000K × 2 h, ~3000K × 1 h) until bedtime. The average (±SE) urinary 6-sulphatoxymelatonin (aMT6s) acrophase time was significantly later in the SLS (6.22 ± 0.34 h) compared to the DLS (4.76 ± 0.53 h) and more variable in SLS compared to DLS (37.2 ± 3.6 min vs. 28.2 ± 2.4 min, respectively, p = .04). Compared to DLS, self-reported sleep was more frequently misaligned relative to circadian phase in SLS RR: 6.75, 95% CI 1.55-29.36, p = .01), but neither self-reported sleep duration nor latency to sleep was different between lighting conditions. Accuracy in the abstract matching and matrix reasoning tests were significantly better in DLS compared to SLS (false discovery rate-adjusted p ≤ .04). Overall, DLS alleviated the drift in circadian phase typically observed in space analog studies and reduced the prevalence of self-reported sleep episodes occurring at an adverse circadian phase. Our results support incorporating DLS in future missions, which may facilitate appropriate circadian alignment and reduce the risk of sleep disruption.
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Affiliation(s)
- Shadab A Rahman
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Brianne A Kent
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Leilah K Grant
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | | | - John P Hanifin
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Laura K Barger
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Charles A Czeisler
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - George C Brainard
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Melissa A St Hilaire
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven W Lockley
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
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Effects of Lighting Interventions to Improve Sleepiness in Night-Shift Workers: A Systematic Review and Meta-Analysis. Healthcare (Basel) 2022; 10:healthcare10081390. [PMID: 35893212 PMCID: PMC9332364 DOI: 10.3390/healthcare10081390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/28/2022] Open
Abstract
Shift work disrupts an otherwise normal circadian rhythm, which may result in sleepiness among night-shift workers. Artificial light has been shown to alter the light–dark cycle of shift workers and reset or phase shift the biological clock, improving nighttime alertness in workers. However, the effect of light therapy on improving sleepiness in nighttime workers has not been effectively confirmed in nursing clinical studies, and it is worth using relevant studies to provide the best evidence in any clinical setting. Systematic review and meta-analysis were used. The study was performed using PRISMA. Academic Search Complete, Embase, MEDLINE, the Cochrane Library, and CINAHL were searched, from the inception of each database to 27 December 2021. The Cochrane risk of bias tool was used to assess the methodological quality of each study. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were synthesized using a random-effects model to assess the efficacy of lighting intervention to improve sleepiness in night-shift workers. Sensitivity analysis followed by subgroup analysis was employed to examine heterogeneity. The meta-analysis was performed using Review Manager 5.4.1 software. A total of 14 studies from 7 countries were included. The overall result shows that lighting interventions significantly improved sleepiness. Further, the blue-enriched white light with a color temperature greater than 5000 Kelvin was effective in improving sleepiness of night-shift workers. This study unveils the emergent knowledge that light interventions with blue-enriched white were effective in improving sleepiness for night-shift workers, including nurses. This finding can be applied to ensure patient safety, reduce accidents, and improve work efficiency and job satisfaction. Nurses constitute the largest health professional workforce. We suggest that hospitals can insert blue-enriched white light equipment for night-shift healthcare providers. Several evidence-based suggestions are made for further consideration.
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Zahed K, Smith A, McDonald AD, Sasangohar F. The Effects of Drowsiness Detection Technology and Education on Nurses' Beliefs and Attitudes Towards Drowsy Driving. IISE Trans Occup Ergon Hum Factors 2022; 10:104-115. [PMID: 35746825 DOI: 10.1080/24725838.2022.2094502] [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] [Indexed: 10/17/2022]
Abstract
Background: Drowsy driving is prevalent among night-shift nurses, yet there is a gap in understanding nurses' beliefs and attitudes that may affect their intention to avoid drowsy driving.Objectives: The objectives of the study were twofold: 1) investigate how behavioral constructs such as beliefs and attitudes may affect nurses' intention to avoid drowsy driving; and 2) assess changes in such beliefs and attitudes during a study that evaluated the effectiveness of educational and technological interventions.Methods: Three-hundred night-shift nurses were recruited from a large hospital in Texas to participate in a randomized control trial. Participants were randomly assigned to three groups: 1) control; 2) educational intervention; and 3) combined educational and technological intervention. The study utilized an integrated model drawing from the constructs of the Theory of Planned Behavior and the Health Belief Model to elicit attitudes, beliefs, and intentions to use in-vehicle drowsiness detection technologies. Each group was surveyed pre- intervention and at post-intervention around 3 months later to assess changes in beliefs and attitudes. Structural equation models and path analysis were used to analyze changes in beliefs.Results: Seventy-nine participants completed the pre-intervention questionnaire, and 44 nurses completed the pre- and post-intervention surveys. Intention was predicted primarily by attitude and perceived health threat. Perceived health threat also mediated the relationship between behavioral intention and the influence of subjective norms as well as perceived behavioral control. Participants who received education about drowsy driving had positive changes in beliefs.Conclusions: Nurses' perceived health threat from driving drowsy and their attitude towards our intervention were important motivators to avoid drowsy driving. Interventions aiming at raising awareness of the risks associated with drowsy driving may be effective at motivating nurses to avoid drowsy driving.
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Affiliation(s)
- Karim Zahed
- Graduate Assistant Researcher - Texas A&M University
| | - Alec Smith
- Graduate Assistant Researcher - Texas A&M University
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11
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Abstract
SignificanceThe function of our biological clock is dependent on environmental light. Rodent studies have shown that there are multiple colors that affect the clock, but indirect measures in humans suggest blue light is key. We performed functional MRI studies in human subjects with unprecedented spatial resolution to investigate color sensitivity of our clock. Here, we show that narrowband blue, green, and orange light were all effective in changing neuronal activity of the clock. While the clock of nocturnal rodents is excited by light, the human clock responds with a decrease in neuronal activity as indicated by a negative BOLD response. The sensitivity of the clock to multiple colors should be integrated in light therapy aimed to strengthen our 24-h rhythms.
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12
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Brown TM, Brainard GC, Cajochen C, Czeisler CA, Hanifin JP, Lockley SW, Lucas RJ, Münch M, O’Hagan JB, Peirson SN, Price LLA, Roenneberg T, Schlangen LJM, Skene DJ, Spitschan M, Vetter C, Zee PC, Wright KP. Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults. PLoS Biol 2022; 20:e3001571. [PMID: 35298459 PMCID: PMC8929548 DOI: 10.1371/journal.pbio.3001571] [Citation(s) in RCA: 79] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ocular light exposure has important influences on human health and well-being through modulation of circadian rhythms and sleep, as well as neuroendocrine and cognitive functions. Prevailing patterns of light exposure do not optimally engage these actions for many individuals, but advances in our understanding of the underpinning mechanisms and emerging lighting technologies now present opportunities to adjust lighting to promote optimal physical and mental health and performance. A newly developed, international standard provides a SI-compliant way of quantifying the influence of light on the intrinsically photosensitive, melanopsin-expressing, retinal neurons that mediate these effects. The present report provides recommendations for lighting, based on an expert scientific consensus and expressed in an easily measured quantity (melanopic equivalent daylight illuminance (melaponic EDI)) defined within this standard. The recommendations are supported by detailed analysis of the sensitivity of human circadian, neuroendocrine, and alerting responses to ocular light and provide a straightforward framework to inform lighting design and practice.
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Affiliation(s)
- Timothy M. Brown
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (TMB); (KPW)
| | - George C. Brainard
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christian Cajochen
- Centre for Chronobiology, University Psychiatric Clinics Basel, Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Charles A. Czeisler
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - John P. Hanifin
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Steven W. Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Robert J. Lucas
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Mirjam Münch
- Centre for Chronobiology, University Psychiatric Clinics Basel, Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
- Research Centre for Hauora and Health, Massey University, Wellington, New Zealand
| | - John B. O’Hagan
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, United Kingdom
| | - Stuart N. Peirson
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Luke L. A. Price
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, United Kingdom
| | - Till Roenneberg
- Institutes for Medical Psychology and Occupational, Social and Environmental Medicine, Medical Faculty, Ludwig-Maximilians University (LMU), Munich, Germany
| | - Luc J. M. Schlangen
- Human Technology Interaction Group, Department of Industrial Engineering and Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
- Intelligent Lighting Institute, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Debra J. Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Manuel Spitschan
- Translational Sensory & Circadian Neuroscience, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- TUM Department of Sport and Health Sciences (TUM SG), Technical University of Munich, Munich, Germany
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Céline Vetter
- Circadian and Sleep Epidemiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Phyllis C. Zee
- Department of Neurology, Northwestern University, Chicago, Illinois, United States of America
- Center for Circadian and Sleep Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Kenneth P. Wright
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America
- * E-mail: (TMB); (KPW)
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13
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Van de Putte E, Kindt S, Bracke P, Stevens M, Vansteenkiste M, Vandevivere L, Ryckaert WR. The influence of integrative lighting on sleep and cognitive functioning of shift workers during the morning shift in an assembly plant. APPLIED ERGONOMICS 2022; 99:103618. [PMID: 34775135 DOI: 10.1016/j.apergo.2021.103618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
It is well known that exposure to light at the right time of the day is important to synchronise our circadian rhythm and enhance cognitive functioning. There is, however, a lack of field studies investigating which lighting characteristics are necessary to improve sleep and cognitive functioning. A controlled field study with 80 shift workers was set up, in which the impact of an integrative lighting (IL) scenario was investigated during the morning shift. Two groups were compared: a control group (no change in lighting settings) and a IL-group (exposed to a melanopic Equivalent Daylight Illuminance of 192 lux, i.e., bright light with a high fraction of short-wavelengths). Pre-post measurement of visual comfort, cognitive functioning (D2 task, go-nogo reaction time task) and sleep (MotionWatch8) were performed. The IL-settings ameliorated sleep efficiency and sleep latency during morning shift and enhanced alertness (not inhibition) compared to standard lighting conditions. Changing lighting settings in an industrial setting should be considered as it seems worthwhile for employees' sleep and cognitive performance.
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Affiliation(s)
- Eowyn Van de Putte
- KU Leuven, Department WaveCore/Light and Lighting Laboratory, Ghent, Belgium.
| | - Sara Kindt
- University of Applied Sciences (Howest), Applied Health and Lifestyle Sciences, Bruges, Belgium
| | - Peter Bracke
- KU Leuven, Department WaveCore/Light and Lighting Laboratory, Ghent, Belgium
| | | | - Maarten Vansteenkiste
- Ghent University, Department of Developmental, Personality and Social Psychology, Ghent, Belgium
| | - Lore Vandevivere
- University of Applied Sciences (Howest), Applied Health and Lifestyle Sciences, Bruges, Belgium
| | - Wouter R Ryckaert
- KU Leuven, Department WaveCore/Light and Lighting Laboratory, Ghent, Belgium
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14
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Doyle MM, Murphy TE, Miner B, Pisani MA, Lusczek ER, Knauert MP. Enhancing Cosinor Analysis of Circadian Phase Markers Using the Gamma Distribution. Sleep Med 2022; 92:1-3. [DOI: 10.1016/j.sleep.2022.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/18/2022] [Indexed: 11/24/2022]
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15
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Exposure to Short Wavelength-Enriched White Light and Exercise Improves Alertness and Performance in Operational NASA Flight Controllers Working Overnight Shifts. J Occup Environ Med 2021; 63:111-118. [PMID: 33065729 DOI: 10.1097/jom.0000000000002054] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE We evaluated the efficacy of a combined short-wavelength-enriched white light and exercise fatigue countermeasure during breaks for flight controllers working overnight shifts. METHODS Twenty NASA flight controllers were studied for two blocks of nightshifts in ISS mission control, randomized to either the control or countermeasure condition. The countermeasure constituted passive exposure to blue-enriched polychromatic lighting for three 20-minute intervals, which included 10 minutes of exercise and occurred before and twice during their shifts. Alertness, performance, and mood were evaluated. RESULTS Flight controllers reported being significantly more alert (P < 0.0001) and happy (P = 0.003) and had faster reaction times (10% slowest responses; P < 0.05) during the countermeasure condition compared to control. CONCLUSIONS The combined light and exercise countermeasure improved alertness, performance, and mood in shift workers overnight. Further research is necessary to determine their relative contribution.
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16
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Sides MB, Johnston SL, Sirek A, Lee PH, Blue RS, Antonsen EL, Basner M, Douglas GL, Epstein A, Flynn-Evans EE, Gallagher MB, Hayes J, Lee SMC, Lockley SW, Monseur B, Nelson NG, Sargsyan A, Smith SM, Stenger MB, Stepanek J, Zwart SR. Bellagio II Report: Terrestrial Applications of Space Medicine Research. Aerosp Med Hum Perform 2021; 92:650-669. [PMID: 34503618 DOI: 10.3357/amhp.5843.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
AbstractINTRODUCTION: For over 50 yr, investigators have studied the physiological adaptations of the human system during short- and long-duration spaceflight exposures. Much of the knowledge gained in developing health countermeasures for astronauts onboard the International Space Station demonstrate terrestrial applications. To date, a systematic process for translating these space applications to terrestrial human health has yet to be defined.METHODS: In the summer of 2017, a team of 38 international scientists launched the Bellagio ll Summit Initiative. The goals of the Summit were: 1) To identify space medicine findings and countermeasures with highest probability for future terrestrial applications; and 2) To develop a roadmap for translation of these countermeasures to future terrestrial application. The team reviewed public domain literature, NASA databases, and evidence books within the framework of the five-stage National Institutes of Health (NIH) translation science model, and the NASA two-stage translation model. Teams then analyzed and discussed interdisciplinary findings to determine the most significant evidence-based countermeasures sufficiently developed for terrestrial application.RESULTS: Teams identified published human spaceflight research and applied translational science models to define mature products for terrestrial clinical practice.CONCLUSIONS: The Bellagio ll Summit identified a snapshot of space medicine research and mature science with the highest probability of translation and developed a Roadmap of terrestrial application from space medicine-derived countermeasures. These evidence-based findings can provide guidance regarding the terrestrial applications of best practices, countermeasures, and clinical protocols currently used in spaceflight.Sides MB, Johnston SL III, Sirek A, Lee PH, Blue RS, Antonsen EL, Basner M, Douglas GL, Epstein A, Flynn-Evans EE, Gallagher MB, Hayes J, Lee SMC, Lockley SW, Monseur B, Nelson NG, Sargsyan A, Smith SM, Stenger MB, Stepanek J, Zwart SR; Bellagio II Team. Bellagio II report: terrestrial applications of space medicine research. Aerosp Med Hum Perform. 2021; 92(8):650669.
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17
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Nie J, Zhou T, Chen Z, Dang W, Jiao F, Zhan J, Chen Y, Chen Y, Pan Z, Kang X, Wang Y, Wang Q, Tang Y, Dong W, Zhou S, Ma Y, Yu X, Zhang G, Shen B. The effects of dynamic daylight-like light on the rhythm, cognition, and mood of irregular shift workers in closed environment. Sci Rep 2021; 11:13059. [PMID: 34158564 PMCID: PMC8219698 DOI: 10.1038/s41598-021-92438-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/10/2021] [Indexed: 02/05/2023] Open
Abstract
Shift workers are mostly suffered from the disruption of circadian rhythm and health problems. In this study, we designed proper light environment to maintain stable circadian rhythm, cognitive performance, and mood status of shift workers. We used five-channel light-emitting diodes to build up the dynamic daylight-like light environment. The illuminance, correlated color temperature, and circadian action factor of light were tunable in the ranges of 226 to 678 lx, 2680 to 7314 K, and 0.32 to 0.96 throughout the day (5:30 to 19:40). During the nighttime, these parameters maintained about 200 lx, 2700 K, and 0.32, respectively. In this light environment, three subjects had engaged in shift work for 38 consecutive days. We measured plasma melatonin, activity counts, continuous performance tests, and visual analogue scale on mood to assess the rhythm, cognitive performance, and mood of subjects. After 38-day shift work, the subjects' peak melatonin concentration increased significantly. Their physiological and behavioral rhythms maintained stable. Their cognitive performance improved significantly after night work, compared with that before night work. Their mood status had no significant change during the 38-day shift work. These results indicated that the light environment was beneficial to maintain circadian rhythm, cognitive performance and mood status during long-term shift work in closed environment.
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Affiliation(s)
- Jingxin Nie
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Tianhang Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Zhizhong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China.
| | - Weimin Dang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China.
| | - Fei Jiao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China
| | - Jinglin Zhan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yifan Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yiyong Chen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Zuojian Pan
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Xiangning Kang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
| | - Yongzhi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Qi Wang
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Yan Tang
- Department of Physical Education, Peking University, Beijing, 100871, China
| | - Wentian Dong
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Shuzhe Zhou
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Yantao Ma
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Xin Yu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Haidian District, 51, Huayuan North Road, Beijing, 100191, China
| | - Guoyi Zhang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
- Dongguan Institute of Optoelectronics, Peking University, Dongguan, 523808, Guangdong, China
| | - Bo Shen
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, 209, Chengfu Road, Haidian District, Beijing, 100871, China
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18
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Cheng P, Walch O, Huang Y, Mayer C, Sagong C, Cuamatzi Castelan A, Burgess HJ, Roth T, Forger DB, Drake CL. Predicting circadian misalignment with wearable technology: validation of wrist-worn actigraphy and photometry in night shift workers. Sleep 2021; 44:5904454. [PMID: 32918087 DOI: 10.1093/sleep/zsaa180] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 07/24/2020] [Indexed: 12/17/2022] Open
Abstract
STUDY OBJECTIVES A critical barrier to successful treatment of circadian misalignment in shift workers is determining circadian phase in a clinical or field setting. Light and movement data collected passively from wrist actigraphy can generate predictions of circadian phase via mathematical models; however, these models have largely been tested in non-shift working adults. This study tested the feasibility and accuracy of actigraphy in predicting dim light melatonin onset (DLMO) in fixed night shift workers. METHODS A sample of 45 night shift workers wore wrist actigraphs before completing DLMO in the laboratory (17.0 days ± 10.3 SD). DLMO was assessed via 24 hourly saliva samples in dim light (<10 lux). Data from actigraphy were provided as input to a mathematical model to generate predictions of circadian phase. Agreement was assessed and compared to average sleep timing on non-workdays as a proxy of DLMO. Model code and an open-source prototype assessment tool are available (www.predictDLMO.com). RESULTS Model predictions of DLMO showed good concordance with in-lab DLMO, with Lin's concordance coefficient of 0.70, which was twice as high as agreement using average sleep timing as a proxy of DLMO. The absolute mean error of the predictions was 2.88 h, with 76% and 91% of the predictions falling with 2 and 4 h, respectively. CONCLUSION This study is the first to demonstrate the use of wrist actigraphy-based estimates of circadian phase as a clinically useful and valid alternative to in-lab measurement of DLMO in fixed night shift workers. Future research should explore how additional predictors may impact accuracy.
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Affiliation(s)
- Philip Cheng
- Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI
| | - Olivia Walch
- Department of Mathematics, University of Michigan, Ann Arbor, MI
| | - Yitong Huang
- Department of Mathematics, University of Michigan, Ann Arbor, MI
| | - Caleb Mayer
- Department of Mathematics, University of Michigan, Ann Arbor, MI
| | - Chaewon Sagong
- Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI
| | | | - Helen J Burgess
- Department of Mathematics, University of Michigan, Ann Arbor, MI
| | - Thomas Roth
- Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI
| | - Daniel B Forger
- Department of Mathematics, University of Michigan, Ann Arbor, MI
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19
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Ferreira FC, Costa RJD, Ruivo Marques D. The Bergen Shift Work Sleep Questionnaire (BSWSQ) – European Portuguese validation in a sample of shift workers from the paper industry. BIOL RHYTHM RES 2021. [DOI: 10.1080/09291016.2021.1913897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
| | | | - Daniel Ruivo Marques
- Department of Education and Psychology, University of Aveiro, Aveiro, Portugal
- University of Coimbra, Coimbra, Portugal
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20
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Alfonsi V, Scarpelli S, Gorgoni M, Pazzaglia M, Giannini AM, De Gennaro L. Sleep-Related Problems in Night Shift Nurses: Towards an Individualized Interventional Practice. Front Hum Neurosci 2021; 15:644570. [PMID: 33796014 PMCID: PMC8007770 DOI: 10.3389/fnhum.2021.644570] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/22/2021] [Indexed: 02/05/2023] Open
Abstract
Rotating shifts (mostly 8- or 12-h) are common among nurses to ensure continuity of care. This scheduling system encompasses several adverse health and performance consequences. One of the most injurious effects of night-time shift work is the deterioration of sleep patterns due to both circadian rhythm disruption and increased sleep homeostatic pressure. Sleep problems lead to secondary effects on other aspects of wellbeing and cognitive functioning, increasing the risk of errors and workplace accidents. A wide range of interventions has been proposed to improve the sleep quality of nurses and promote an increase in attention levels. In recent years, particular attention has been paid to individual and environmental factors mediating the subjective ability to cope with sleep deprivation during the night shift. Given the predictive role of these factors on the negative impact of a night shift, an individualized intervention could represent an effective countermeasure by ensuring suitable management of shift schedules. Therefore, the aims of this mini-review are to: (a) provide an updated overview of the literature on sleep problems in night shift nurses and their adverse consequences; and (b) critically analyze the psychosocial factors that mediate the negative impact of shift work with the ultimate goal of defining an effective countermeasure based on an individualized approach.
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Affiliation(s)
- Valentina Alfonsi
- Body and Action Lab, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Psychology, Sapienza University of Rome, Rome, Italy
| | | | - Maurizio Gorgoni
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Mariella Pazzaglia
- Body and Action Lab, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Psychology, Sapienza University of Rome, Rome, Italy
| | | | - Luigi De Gennaro
- Body and Action Lab, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Psychology, Sapienza University of Rome, Rome, Italy
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21
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Houser KW, Esposito T. Human-Centric Lighting: Foundational Considerations and a Five-Step Design Process. Front Neurol 2021; 12:630553. [PMID: 33584531 PMCID: PMC7873560 DOI: 10.3389/fneur.2021.630553] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/06/2021] [Indexed: 12/22/2022] Open
Abstract
At its best, human-centric lighting considers the visual and non-visual effects of light in support of positive human outcomes. At its worst, it is a marketing phrase used to healthwash lighting products or lighting design solutions. There is no doubt that environmental lighting contributes to human health, but how might one practice human-centric lighting given both the credible potential and the implausible hype? Marketing literature is filled with promises. Technical lighting societies have summarized the science but have not yet offered design guidance. Meanwhile, designers are in the middle, attempting to distinguish credible knowledge from that which is dubious to make design decisions that affect people directly. This article is intended to: (1) empower the reader with fundamental understandings of ways in which light affects health; (2) provide a process for human-centric lighting design that can dovetail with the decision-making process that is already a part of a designer's workflow.
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Affiliation(s)
- Kevin W. Houser
- School of Civil and Construction Engineering, Oregon State University, Corvallis, OR, United States
- Advanced Lighting Team, Pacific Northwest National Laboratory, Portland, OR, United States
| | - Tony Esposito
- Lighting Research Solutions LLC, Cambridge, MA, United States
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22
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Sletten TL, Raman B, Magee M, Ferguson SA, Kennaway DJ, Grunstein RR, Lockley SW, Rajaratnam SMW. A Blue-Enriched, Increased Intensity Light Intervention to Improve Alertness and Performance in Rotating Night Shift Workers in an Operational Setting. Nat Sci Sleep 2021; 13:647-657. [PMID: 34079409 PMCID: PMC8163632 DOI: 10.2147/nss.s287097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022] Open
Abstract
PURPOSE This study examined the efficacy of a lighting intervention that increased both light intensity and short-wavelength (blue) light content to improve alertness, performance and mood in night shift workers in a chemical plant. PATIENTS AND METHODS During rostered night shifts, 28 workers (46.0±10.8 years; 27 male) were exposed to two light conditions each for two consecutive nights (~19:00-07:00 h) in a counterbalanced repeated measures design: traditional-spectrum lighting set at pre-study levels (43 lux, 4000 K) versus higher intensity, blue-enriched lighting (106 lux, 17,000 K), equating to a 4.5-fold increase in melanopic illuminance (24 to 108 melanopic illuminance). Participants completed the Karolinska Sleepiness Scale, subjective mood ratings, and the Psychomotor Vigilance Task (PVT) every 2-4 hours during the night shift. RESULTS A significant main effect of time indicated KSS, PVT mean reaction time, number of PVT lapses (reaction times > 500 ms) and subjective tension, misery and depression worsened over the course of the night shift (p<0.05). Percentage changes in KSS (p<0.05, partial η2=0.14) and PVT mean reaction time (p<0.05, partial η2=0.19) and lapses (p<0.05, partial η2=0.17) in the middle and end of night shift, expressed relative to start of shift, were significantly improved during the lighting intervention compared to the traditional lighting condition. Self-reported mood did not significantly differ between conditions (p>0.05). CONCLUSION Our findings, showing improvements in alertness and performance with exposure to blue-enriched, increased intensity light, provide support for light to be used as a countermeasure for impaired alertness in night shift work settings.
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Affiliation(s)
- Tracey L Sletten
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Bhairavi Raman
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michelle Magee
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, Goodwood, SA, Australia
| | - David J Kennaway
- Robinson Research Institute, School of Medicine, Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, SA, Australia
| | - Ronald R Grunstein
- Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia.,Department of Respiratory & Sleep Medicine, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Steven W Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Shantha M W Rajaratnam
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
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Sunde E, Pedersen T, Mrdalj J, Thun E, Grønli J, Harris A, Bjorvatn B, Waage S, Skene DJ, Pallesen S. Alerting and Circadian Effects of Short-Wavelength vs. Long-Wavelength Narrow-Bandwidth Light during a Simulated Night Shift. Clocks Sleep 2020; 2:502-522. [PMID: 33255613 PMCID: PMC7712639 DOI: 10.3390/clockssleep2040037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/12/2020] [Accepted: 11/23/2020] [Indexed: 11/18/2022] Open
Abstract
Light can be used to facilitate alertness, task performance and circadian adaptation during night work. Novel strategies for illumination of workplaces, using ceiling mounted LED-luminaires, allow the use of a range of different light conditions, altering intensity and spectral composition. This study (ClinicalTrials.gov Identifier NCT03203538) investigated the effects of short-wavelength narrow-bandwidth light (λmax = 455 nm) compared to long-wavelength narrow-bandwidth light (λmax = 625 nm), with similar photon density (~2.8 × 1014 photons/cm2/s) across light conditions, during a simulated night shift (23:00–06:45 h) when conducting cognitive performance tasks. Light conditions were administered by ceiling mounted LED-luminaires. Using a within-subjects repeated measurements study design, a total of 34 healthy young adults (27 females and 7 males; mean age = 21.6 years, SD = 2.0 years) participated. The results revealed significantly reduced sleepiness and improved task performance during the night shift with short-wavelength light compared to long-wavelength light. There was also a larger shift of the melatonin rhythm (phase delay) after working a night shift in short-wavelength light compared to long-wavelength light. Participants’ visual comfort was rated as better in the short-wavelength light than the long-wavelength light. Ceiling mounted LED-luminaires may be feasible to use in real workplaces, as these have the potential to provide light conditions that are favorable for alertness and performance among night workers.
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Affiliation(s)
- Erlend Sunde
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (A.H.); (S.P.)
- Correspondence: ; Tel.: +47-93638159
| | - Torhild Pedersen
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (T.P.); (J.M.); (J.G.)
| | - Jelena Mrdalj
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (T.P.); (J.M.); (J.G.)
| | - Eirunn Thun
- Department of Clinical Psychology, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway;
| | - Janne Grønli
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (T.P.); (J.M.); (J.G.)
| | - Anette Harris
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (A.H.); (S.P.)
| | - Bjørn Bjorvatn
- Department of Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, 5020 Bergen, Norway; (B.B.); (S.W.)
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, 5021 Bergen, Norway
| | - Siri Waage
- Department of Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, 5020 Bergen, Norway; (B.B.); (S.W.)
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, 5021 Bergen, Norway
| | - Debra J. Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK;
| | - Ståle Pallesen
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, 5020 Bergen, Norway; (A.H.); (S.P.)
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, 5021 Bergen, Norway
- Optentia Research Focus Area, North-West University, Vanderbijlpark 1900, South Africa
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Chen Y, Broman AT, Priest G, Landrigan CP, Rahman SA, Lockley SW. The Effect of Blue-Enriched Lighting on Medical Error Rate in a University Hospital ICU. Jt Comm J Qual Patient Saf 2020; 47:165-175. [PMID: 33341396 DOI: 10.1016/j.jcjq.2020.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 12/28/2022]
Abstract
BACKGROUND Fatigue-related errors that occur during patient care impose a tremendous socioeconomic impact on the health care system. Blue-enriched light has been shown to promote alertness and attention. The present study tested whether blue-enriched light can help to reduce medical errors in a university hospital adult ICU. METHODS In this interventional study, a blue-enriched white light emitting diode was used to enhance traditional fluorescent light at the nurse workstation and common areas in the ICU. Medical errors were identified retrospectively using an established two-step surveillance process. Suspected incidents of potential errors detected on nurse chart review were subsequently reviewed by two physicians blinded to lighting conditions, who made final classifications. Error rates were compared between the preintervention fluorescent and postintervention blue-enriched lighting conditions using Poisson regression. RESULTS The study included a total of 1,073 ICU admissions, 522 under traditional and 551 under interventional lighting (age range 17-97 years, mean age ± standard deviation 58.5 ± 15.8). No difference was found in overall medical error rate (harmful and non-harmful) pre- vs. postintervention, 45.5 vs. 42.7 per 1,000 patient-days (rate ratio: 0.94, 95% confidence interval = 0.71-1.23, p = 0.64). CONCLUSION Interventional lighting did not have an effect on overall medical error rate. The study was likely underpowered to detect the 25% error reduction predicted. Future studies are required that are powered to assess more modest effects for lighting to reduce the risk of fatigue-related medical errors and errors of differing severity.
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Sunde E, Pedersen T, Mrdalj J, Thun E, Grønli J, Harris A, Bjorvatn B, Waage S, Skene DJ, Pallesen S. Blue-Enriched White Light Improves Performance but Not Subjective Alertness and Circadian Adaptation During Three Consecutive Simulated Night Shifts. Front Psychol 2020; 11:2172. [PMID: 33013558 PMCID: PMC7462016 DOI: 10.3389/fpsyg.2020.02172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/03/2020] [Indexed: 01/28/2023] Open
Abstract
Use of blue-enriched light has received increasing interest regarding its activating and performance sustaining effects. However, studies assessing effects of such light during night work are few, and novel strategies for lighting using light emitting diode (LED) technology need to be researched. In a counterbalanced crossover design, we investigated the effects of a standard polychromatic blue-enriched white light (7000 K; ∼200 lx) compared to a warm white light (2500 K), of similar photon density (∼1.6 × 1014 photons/cm2/s), during three consecutive simulated night shifts. A total of 30 healthy participants [10 males, mean age 23.3 (SD = 2.9) years] were included in the study. Dependent variables comprised subjective alertness using the Karolinska Sleepiness Scale, a psychomotor vigilance task (PVT) and a digit symbol substitution test (DSST), all administered at five time points throughout each night shift. We also assessed dim-light melatonin onset (DLMO) before and after the night shifts, as well as participants' opinion of the light conditions. Subjective alertness and performance on the PVT and DSST deteriorated during the night shifts, but 7000 K light was more beneficial for performance, mainly in terms of fewer errors on the PVT, at the end of the first- and second- night shift, compared to 2500 K light. Blue-enriched light only had a minor impact on PVT response times (RTs), as only the fastest 10% of the RTs were significantly improved in 7000 K compared to 2500 K light. In both 7000 and 2500 K light, the DLMO was delayed in those participants with valid assessment of this parameter [n = 20 (69.0%) in 7000 K light, n = 22 (78.6%) in 2500 K light], with a mean of 2:34 (SE = 0:14) and 2:12 (SE = 0:14) hours, respectively, which was not significantly different between the light conditions. Both light conditions were positively rated, although participants found 7000 K to be more suitable for work yet evaluated 2500 K light as more pleasant. The data indicate minor, but beneficial, effects of 7000 K light compared to 2500 K light on performance during night work. Circadian adaptation did not differ significantly between light conditions, though caution should be taken when interpreting these findings due to missing data. Field studies are needed to investigate similar light interventions in real-life settings, to develop recommendations regarding illumination for night workers. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03203538.
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Affiliation(s)
- Erlend Sunde
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Torhild Pedersen
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
| | - Jelena Mrdalj
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
| | - Eirunn Thun
- Department of Clinical Psychology, University of Bergen, Bergen, Norway
| | - Janne Grønli
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
| | - Anette Harris
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Bjørn Bjorvatn
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway
| | - Siri Waage
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway
| | - Debra J Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Ståle Pallesen
- Department of Psychosocial Science, University of Bergen, Bergen, Norway
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway
- Optentia, North-West University Vaal Triangle Campus, Vanderbijlpark, South Africa
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26
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Night-shift nurses and drowsy driving: A qualitative study. Int J Nurs Stud 2020; 112:103600. [PMID: 32703687 DOI: 10.1016/j.ijnurstu.2020.103600] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/23/2020] [Accepted: 03/27/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND Drowsy driving following the night shift is persistent among nurses resulting in elevated rates of vehicle crashes and crash-related injuries and deaths. While considerable effort has been dedicated to the development of countermeasures, implementation of these countermeasures in nursing has lagged behind other shift work oriented industries. Developing effective countermeasures for drowsy driving in nurses requires a thorough characterization of nurse's perceptions of drowsy driving and potential mitigations. OBJECTIVE The objective of this research was to elicit night shift nurses' perceptions of drowsy driving, countermeasures, and educational and technological interventions. DESIGN Perceptions were elicited through a semi-structured interview protocol. The protocol design was driven by previously identified research gaps. Questions focused on four topics: perceptions of drowsy driving, current practices and methods to mitigate drowsiness during the shift and commute, preferences and expectations for training on drowsiness management, and, preferences and expectations for technological mitigations. SETTING The data collection took place at a large urban hospital in Texas, USA. PARTICIPANTS Thirty night-shift nurses were recruited with voluntary sampling. No nurses declined to participate after initially consenting. The participants were male and female nurses who currently worked a 12 hour night shift. The nurses had between 1 and more than 20 years of experience and worked in a variety of units. METHOD The interview recordings were transcribed by the research team and entered into a qualitative data analysis software. Transcripts were analyzed by two independent coders with a grounded theory approach to identify common themes and subthemes across participants. FINDINGS Feelings of drowsiness typically manifested immediately following the shift or during the post work commute. Nurses responded to drowsiness by engaging in multiple ineffective countermeasures (e.g., listening to music) and effective countermeasures (e.g., naps) were used sparingly. Experiences and mitigation methods traversed through the nurses' social network although they did not always alter behavior. Nurses were uncertain but enthusiastic about educational and technological interventions preferring practical training and auditory interactive alerts. CONCLUSIONS The findings suggest a strong need for real time drowsiness interventions during or immediately prior to nurses' post work commutes. Nurses' enthusiasm for training and technology to prevent drowsy driving suggests high levels of readiness and acceptance for such interventions. Future work should focus on the development and implementation of practical training and technological interventions for drowsy driving in nurses.
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Good CH, Brager AJ, Capaldi VF, Mysliwiec V. Sleep in the United States Military. Neuropsychopharmacology 2020; 45:176-191. [PMID: 31185484 PMCID: PMC6879759 DOI: 10.1038/s41386-019-0431-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/23/2019] [Accepted: 05/31/2019] [Indexed: 02/07/2023]
Abstract
The military lifestyle often includes continuous operations whether in training or deployed environments. These stressful environments present unique challenges for service members attempting to achieve consolidated, restorative sleep. The significant mental and physical derangements caused by degraded metabolic, cardiovascular, skeletomuscular, and cognitive health often result from insufficient sleep and/or circadian misalignment. Insufficient sleep and resulting fatigue compromises personal safety, mission success, and even national security. In the long-term, chronic insufficient sleep and circadian rhythm disorders have been associated with other sleep disorders (e.g., insomnia, obstructive sleep apnea, and parasomnias). Other physiologic and psychologic diagnoses such as post-traumatic stress disorder, cardiovascular disease, and dementia have also been associated with chronic, insufficient sleep. Increased co-morbidity and mortality are compounded by traumatic brain injury resulting from blunt trauma, blast exposure, and highly physically demanding tasks under load. We present the current state of science in human and animal models specific to service members during- and post-military career. We focus on mission requirements of night shift work, sustained operations, and rapid re-entrainment to time zones. We then propose targeted pharmacological and non-pharmacological countermeasures to optimize performance that are mission- and symptom-specific. We recognize a critical gap in research involving service members, but provide tailored interventions for military health care providers based on the large body of research in health care and public service workers.
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Affiliation(s)
- Cameron H. Good
- 0000 0001 2151 958Xgrid.420282.ePhysical Scientist, US Army Research Laboratory, Aberdeen Proving Ground, MD, 21005 USA
| | - Allison J. Brager
- 0000 0001 0036 4726grid.420210.5Sleep Research Center, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910 USA
| | - Vincent F. Capaldi
- 0000 0001 0036 4726grid.420210.5Department of Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Silver Spring, MD 20910 USA
| | - Vincent Mysliwiec
- 0000 0004 0467 8038grid.461685.8San Antonio Military Health System, Department of Sleep Medicine, JBSA, Lackland, TX 78234 USA
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28
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Savarese M, Di Perri MC. Excessive sleepiness in shift work disorder: a narrative review of the last 5 years. Sleep Breath 2019; 24:297-310. [PMID: 31471831 DOI: 10.1007/s11325-019-01925-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 07/26/2019] [Accepted: 08/16/2019] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Shift work sleep disorder (SWSD), also known as shift work disorder (SWD), is a circadian rhythm sleep disorder characterized by insomnia and/or excessive sleepiness, associated with a recurring work schedule that overlaps the usual time designated for sleeping. PURPOSE This article aims to provide a narrative review of the pharmacological trials conducted on SWD in the last 5 years, to better address safety and health issues inherent to this disorder. METHODS An electronic literature search was conducted using PubMed. All eligible randomized controlled trials (RCTs) and cross-over RCTs with employees undertaking shift work (including night shifts) were considered, yielding three articles. RESULTS All three studies showed the efficacy of armodafinil in improving subjective and objective sleepiness, clinical conditions, and global functioning regardless of shift duration. Both performance and driving simulator performance tests administered during the night shift bore better results following armodafinil administration than after placebo. However, armodafinil only reduced subjective disability in individuals working more than 9 h; furthermore, even after armodafinil, alertness was reduced but not normalized. CONCLUSION These studies underscore the importance of preventing and/or minimizing disturbances due to shift work. This may be achieved through various strategies, such as the employer's commitment to adopt ergonomic criteria in shift design and to implement work-environment interventions like controlled bright light. Health personnel is of pivotal importance to detect potential factors of intolerance to shift work or early symptoms of SWD. Additional and improved studies are needed to further evaluate the effectiveness and safety of both pharmacological and non-pharmacological interventions.
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Affiliation(s)
- Mariantonietta Savarese
- "FM Puca" Neurology Unit, University Hospital Consortium Corporation Polyclinic of Bari, 70124, Bari, Italy
| | - Maria Caterina Di Perri
- Center of Sleep Medicine, UOSD of Neurophysiopathology and Disorders of Movement, AOU G Martino, Department of Clinical and Experimental Medicine, University of Messina, 98121, Messina, Italy.
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Molzof HE, Prapanjaroensin A, Patel VH, Mokashi MV, Gamble KL, Patrician PA. Misaligned core body temperature rhythms impact cognitive performance of hospital shift work nurses. Neurobiol Learn Mem 2019; 160:151-159. [PMID: 30611883 DOI: 10.1016/j.nlm.2019.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 12/15/2018] [Accepted: 01/01/2019] [Indexed: 12/16/2022]
Abstract
Circadian rhythms greatly influence 24-h variation in cognition in nearly all organisms, including humans. Circadian clock impairment and sleep disruption are detrimental to hippocampus-dependent memory and negatively influence the acquisition and recall of learned behaviors. The circadian clock can become out of sync with the environment during circadian misalignment. Shift work represents a real-world model of circadian misalignment that can be studied for its physiological implications. The present study aimed to test the hypothesis that circadian misalignment disrupts vigilance and cognitive performance on occupationally relevant tasks using shift work as a model. As such, we sought to (1) explore the general effects of night- and day-shift worker schedules on sleep-wake parameters and core body temperature (CBT) phase, and (2) determine whether shift-type and CBT phase impact cognitive performance and vigilance at the end of a 12-h shift. We observed a sample of day-shift and night-shift hospital nurses over a 10-day period. At the end of three, consecutive, 12-h shifts (7 pm-7am or 7am-7 pm), participants completed a cognitive battery assessing vigilance, cognitive throughput, and medication calculation fluency (via an investigator developed and tested metric). Night-shift nurses exhibited significantly greater sleep fragmentation as well as a greater disparity between their wake-time and time of CBT minimum compared to day-shift nurses. Night-shift nurses exhibited significantly slower cognitive proficiency at the end of their shifts, even after adjustment for CBT phase. These results suggest that circadian disruption and reduced sleep quality both contribute to cognitive functioning and performance.
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Affiliation(s)
- Hylton E Molzof
- Department of Psychology, University of Alabama at Tuscaloosa, Tuscaloosa, AL, USA
| | | | - Vivek H Patel
- School of Medicine, Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mugdha V Mokashi
- School of Medicine, Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karen L Gamble
- School of Medicine, Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Patricia A Patrician
- UAB School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA.
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30
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Hanifin J, Lockley S, Cecil K, West K, Jablonski M, Warfield B, James M, Ayers M, Byrne B, Gerner E, Pineda C, Rollag M, Brainard G. Randomized trial of polychromatic blue-enriched light for circadian phase shifting, melatonin suppression, and alerting responses. Physiol Behav 2019; 198:57-66. [DOI: 10.1016/j.physbeh.2018.10.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/06/2018] [Accepted: 10/03/2018] [Indexed: 11/25/2022]
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Griepentrog JE, Labiner HE, Gunn SR, Rosengart MR. Bright environmental light improves the sleepiness of nightshift ICU nurses. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:295. [PMID: 30424793 PMCID: PMC6234544 DOI: 10.1186/s13054-018-2233-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/15/2018] [Indexed: 12/21/2022]
Abstract
Background Shift work can disturb circadian homeostasis and result in fatigue, excessive sleepiness, and reduced quality of life. Light therapy has been shown to impart positive effects in night shift workers. We sought to determine whether or not prolonged exposure to bright light during a night shift reduces sleepiness and enhances psychomotor performance among ICU nurses. Methods This is a single-center randomized, crossover clinical trial at a surgical trauma ICU. ICU nurses working a night shift were exposed to a 10-h period of high illuminance (1500–2000 lx) white light compared to standard ambient fluorescent lighting of the hospital. They then completed the Stanford Sleepiness Scale and the Psychomotor Vigilance Test. The primary and secondary endpoints were analyzed using the paired t test. A p value <0.05 was considered significant. Results A total of 43 matched pairs completed both lighting exposures and were analyzed. When exposed to high illuminance lighting subjects experienced reduced sleepiness scores on the Stanford Sleepiness Scale than when exposed to standard hospital lighting: mean (sem) 2.6 (0.2) vs. 3.0 (0.2), p = 0.03. However, they committed more psychomotor errors: 2.3 (0.2) vs. 1.7 (0.2), p = 0.03. Conclusions A bright lighting environment for ICU nurses working the night shift reduces sleepiness but increases the number of psychomotor errors. Trial registration ClinicalTrials.gov, NCT03331822. Retrospectively registered on 6 November 2017.
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Affiliation(s)
- John E Griepentrog
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street - Suite F1266.1, Pittsburgh, PA, 15213, USA
| | - Hanna E Labiner
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street - Suite F1266.1, Pittsburgh, PA, 15213, USA
| | - Scott R Gunn
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, 200 Lothrop Street - Suite F1266.1, Pittsburgh, PA, 15213, USA. .,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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33
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Mortazavi SMJ. Comment on 'Domestic light at night and breast cancer risk: a prospective analysis of 105 000 UK women in the Generations Study'. Br J Cancer 2018; 118:1536. [PMID: 29769746 PMCID: PMC5988714 DOI: 10.1038/s41416-018-0060-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/09/2018] [Accepted: 02/22/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
- S M J Mortazavi
- Department of Diagnostic Imaging, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA, 19111, USA. .,Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran.
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