Prevalence of Shift Work Disorder: A Systematic Review and Meta-Analysis

Comparison of Tailored Versus Standard Group Cognitive Behavioral Therapy for Shift Worker Insomnia: A Randomized Controlled Trial

Shift workers are at increased risk of insomnia. The standard treatment (cognitive behavioral therapy for insomnia) poses significant challenges for this demographic due to irregular work and sleep schedules. New approaches are still considered insufficient due to high attrition or insufficient effectiveness. Our preliminary study identified sleep-relevant state and trait factors (see secondary outcomes) for incorporation into an innovative manual that addresses sleep in an implicit manner. The objective was to reduce the focus on insomnia and to replace regularity-based interventions. With a sample of 55 insomniacs (67.74% male, mean age 41.62 years), standard and customized treatments were compared using pre-treatment, post-treatment, and three-month follow-up measurements (RCT, self-assessment data). Our linear mixed models revealed the main significant effects of the measurement point for the primary (insomnia severity, sleep quality, sleep onset latency, total sleep time, daytime sleepiness) and the secondary outcomes (selection: anxiety/depression, dysfunctional beliefs, arousal, emotional stability, concern). No main effects of the condition or interaction effects were identified. Non-inferiority and equivalence tests demonstrated that the customized treatment is equivalent to standard therapy, which is a favorable outcome in light of the implicit approach. Consequently, this innovative approach warrants further exploration, incorporating the present results.

Effectiveness of digital cognitive behavioral therapy for insomnia in nurses with shift work sleep disorder: Results of a randomized controlled trial

BACKGROUND

Shift work is associated with many adverse effects on health and, in particular, affects sleep. In nurses, one of the most common forms of insomnia is shift work sleep disorder. Traditional face-to-face cognitive behavioral therapy for insomnia is often impractical for shift-working nurses due to irregular work schedules. Digital therapy presents a promising alternative to provide nurses with access to cognitive behavioral therapy for insomnia.

OBJECTIVE

To investigate the effectiveness of the digital SleepCare intervention for reducing insomnia in nurses being affected by shift work sleep disorder.

DESIGN

Randomized controlled trial.

PARTICIPANTS

74 nurses affected by shift work sleep disorder.

METHODS

In a two-armed randomized controlled trial, SleepCare was compared to shift work-specific psychoeducation published digitally by the German Sleep Society. The diagnosis of shift work sleep disorder was established through a clinical interview. The primary outcome was insomnia severity as measured by the Insomnia Severity Index at baseline before randomization, at 8 weeks, and 3 months after randomization. Further indicators of mental health and long-term hair cortisol concentration were evaluated as secondary endpoints.

RESULTS

Intention-to-treat analysis of covariance showed a greater reduction in insomnia severity in the intervention group versus psychoeducation, at both post-intervention (d = 1.11[0.7-1.6]) and follow-up (d = 0.97 [0.5-1.4]), corresponding to between-group differences of 5.0 and 5.3 points on the Insomnia Severity Index, respectively. 56 % completed at least five of the six sessions and results indicated larger effects for these intervention completers with d = 1.49 and d = 1.28, respectively. Statistically significant effects were observed for sleep-related, but not other mental health indicators, for example, stress and depression. Reduced hair cortisol levels were observed post-intervention in the SleepCare group (V = 82, p = .008; Δ = -1.8 pg/mg, 44 % reduction from baseline).

CONCLUSIONS

SleepCare was effective in reducing insomnia symptoms to a clinically meaningful extent and is one of the first digitally delivered programs to adapt cognitive behavioral therapy for insomnia with specific exercises to address nurses' needs for shift work. The development of effective strategies to promote treatment adherence seems necessary, as substantially larger effects were observed for intervention completers.

REGISTRATION

German Clinical Trials Register - DRKS; DRKS00027411 (https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00027411). Registration date: March 9, 2022. Start of recruitment: May 13, 2022.

Sleep disorders among Tunisian night-shift workers: a cross-sectional study

PURPOSE

Night shift work is common today and disrupts circadian rhythms, leading to health concerns. This study examines the impact of night shifts on sleep quality among Tunisian workers, determines the prevalence of sleep disorders, and identifies factors associated with poor sleep quality.

METHODOLOGY

This cross-sectional study employed an online questionnaire to assess sleep disorders among night workers aged 18 and older. Key measures included sleep quality, daytime alertness, mood, and subjective well-being, assessed with validated Arabic versions of the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Patient Health Questionnaire-9 (PHQ-9), and WHO-Five Well-Being Index (WHO-5).

RESULTS

A study of 503 Tunisian night shift workers aged 25 to 64 revealed significant sleep disturbances. Poor sleep quality (PSQI score > 5) was found in 59.4%, while 13.7% reported insomnia (ISI score > 15). Severe insomnia, excessive daytime sleepiness, severe depression, and poor well-being were present in 2%, 32.6%, 4%, and 58.3%, respectively. Factors linked to poor sleep quality included BMI, active smoking, fatty meals, hypnotic use, nasal obstruction, sinusitis, gastrointestinal disorders, and well-being scores.

CONCLUSION

The findings of this study highlight the significant impact of night shift work on sleep quality and overall well-being among Tunisian workers. To mitigate these effects, practical interventions are essential, including promoting shift work schedules, improving workplace wellness programs, encouraging healthier lifestyle choices, and providing access to mental health support. Future research should investigate the relationship between shift work, sleep, and mental health while finding ways to mitigate these effects.

Orexinergic modulation of chronic jet lag-induced deficits in mouse cognitive flexibility

Cognitive flexibility and working memory are important executive functions mediated by the prefrontal cortex and can be impaired by circadian rhythm disturbances such as chronic jet lag (CJL) or shift work. In the present study, we used mice to investigate whether (1) simulated CJL impairs cognitive flexibility, (2) the orexin system is involved in such impairment, and (3) nasal administration of orexin A is able to reverse CJL-induced deficits in cognitive flexibility and working memory. Mice were exposed to either standard light-dark conditions or simulated CJL consisting of series of advance time shifts. Experiment (1) investigated the effects of a mild CJL protocol on cognitive flexibility using the attentional set shifting task. Experiment (2) used a stronger CJL protocol and examined CJL effects on the orexin system utilizing c-Fos and orexin immunohistochemistry. Experiment (3) tested whether nasal orexin application can rescue CJL-induced deficits in cognitive flexibility and working memory, the latter by measuring spontaneous alternation in the Y-maze. The present data show that CJL (1) impairs cognitive flexibility and (2) reduces the activity of orexin neurons in the lateral hypothalamus. (3) Nasal administration of orexin A rescued CJL-induced deficits in working memory and cognitive flexibility. These findings suggest that executive function impairments by circadian rhythm disturbances such as CJL are caused by dysregulation of orexinergic input to the prefrontal cortex. Compensation of decreased orexinergic input by nasal administration of orexin A could be a potential therapy for CJL- or shift work-induced human deficits in executive functions.

Night and shift work and incidence of physician-diagnosed sleep disorders in nursing staff: A prospective cohort study

BACKGROUND

Epidemiological studies provide evidence for an association between shift work and sleep problems but often lack precise exposure and outcome data.

OBJECTIVE

To investigate the risk of first-time physician-diagnosed sleep disorder in nursing staff using register-based data of shift work and health outcomes.

DESIGN

A prospective cohort study with a 4.5-year follow-up.

PARTICIPANTS

25,639 healthcare employees (nurses including midwives, nursing assistants, and related care professions) employed for at least six months between 2012 and 2016 by Region Stockholm were included.

METHODS

Information on hour-by-hour and day-by-day working hours was obtained from a computerised employee register. Physician-diagnosed sleep disorders (N = 326) were obtained from an outpatient register from January 2013 to June 2017. Discrete time proportional hazards models were used to estimate hazard ratios (HR) adjusting for age, sex, country of birth and profession.

RESULTS

An increased risk of physician-diagnosed sleep disorder was seen among those who, during the preceding six months, only or frequently (>66 times) worked night shifts compared to those who did not work nights (HR 1.70, 95 % CI 1.17-2.43 and HR 1.77, 95 % CI 1.21-2.50 respectively). The associations were supported by a dose-response pattern (p = 0.0006). Among those who work night shifts, the risk associated with 9-12 times of three or more consecutive nights was of borderline statistical significance (HR 1.66, 95 % CI 0.98-2.81). Frequently (>39 times the last six months) having quick returns from night shifts (<28 h) showed an almost 2-fold increased risk of physician-diagnosed sleep disorder compared to those who had few (<8 times in the last six months) quick returns from night shifts (HR 1.89, 95 % CI 1.05-3.52). Quick returns from afternoon shifts in non-night workers (<11 h) did not significantly increase the risk of physician-diagnosed sleep disorder.

CONCLUSION

The results indicate that intensive night shift work, especially frequent and consecutive night shifts, is associated with an increased risk of physician-diagnosed sleep disorder in nursing staff. This study raises awareness of the need to acknowledge objective in addition to subjective health outcomes in relation to shift work.

The relationship between shift work, sleep, and work hours on wellbeing

We investigated the role of sleep and work hours on wellbeing among day- and shift workers. We tested a mediation-moderation hypothesis proposing that; 1) sleep would mediate the association between the work schedule and the impact of sleep/sleepiness on wellbeing; 2) work hours would moderate the link between work schedule and sleep. We made random phone calls to 1,162 participants and identified 172-d and 130 shift workers that worked ≥35 h/week. The work schedule had a positive indirect effect on the impact of sleep/sleepiness via sleep duration (β=0.0511, SE=0.0309, [0.0008, 0.3219]. The relationship between shift work and sleep duration was negative (β=-0.35, SE=0.14, p<0.01), and sleep duration was negatively associated with a greater impact of sleep/sleepiness on wellbeing (β=-0.15, SE=0.06, p<0.02). The path between the work schedule and sleep duration was moderated by work hours; fewer work hours resulted in shift workers reporting a greater impact of sleep/sleepiness on wellbeing. The results support the mediation-moderation hypothesis. Work hours and sleep duration are key characteristics in work schedule design.

Association Between Shift Work and Vitamin D Levels in Brazilian Female Workers

Objectives: Vitamin D plays a crucial role in maintaining bone and muscle health and is associated with various health conditions. Risk factors for reduced vitamin D levels include occupation. The aim of this study was to explore the association between shift work and vitamin D levels among female workers. Methods: This cross-sectional study was conducted among 304 women from an industrial group located in southern Brazil. Vitamin D deficiency was defined as serum 25(OH)D levels < 20 ng/mL, and deficiency/insufficiency was defined as serum levels < 30 ng/mL. Work shift data were collected through interviews using the start and end times of work shifts, classified as "day shift" (6:00 AM ≤ hh:hh < 10:00 PM) and "night shift" (10:00 PM ≤ hh:hh < 6:00 AM), respectively. The association between vitamin D deficiency and shift work was expressed as prevalence ratio (PR), using Poisson regression adjusted for confounding variables. Results: The prevalence of vitamin D deficiency was 36.5% (95% CI: 31.1-41.9), while the prevalence of insufficiency was 75.7% (95% CI: 70.8-80.5). After adjustment, a significant association was found, with 65% and 17% higher probabilities of having vitamin D deficiency (PR = 1.65; 95% CI: 1.23-2.22; p = 0.001) and vitamin D deficiency/insufficiency (PR = 1.17; 95% CI: 1.02-1.35; p = 0.030) among nightshift workers compared with dayshift workers. Conclusions: The findings of this study indicate a high prevalence of hypovitaminosis D among Brazilian female fixed-shift workers as well as a higher probability of vitamin D deficiency and deficiency/insufficiency among nightshift workers compared with dayshift workers.

Identifying Risk and Protective Factors for Shift Work Sleep Disorder: Insights from UK Biobank Night Shift Workers

Shift Work Sleep Disorder (SWSD) is a significant and highly prevalent condition affecting up to 48% of individuals with irregular work schedules. The diagnostic criteria for SWSD include persistent insomnia or sleepiness in relation to shift work, not attributable to other disorders or external factors. To explore risk factors of SWSD, we conducted a cross-sectional analysis among 10,787 night shift workers in the UK Biobank. To determine correlates of SWSD using multivariable-adjusted logistic regression models, a preselection of potential risk factors was made on the basis of previous literature. Self-identifying as 'Asian or Asian British' or 'Black or Black British' (compared to being 'White'), male sex, and high scores on sociability, warmth and diligence were associated with lower odds for SWSD. We did not find significant associations of chronotype, frequency of alcohol intake, smoking, and time employed in current job with SWSD. These findings underscore the need for targeted interventions and workplace policies to mitigate the adverse effects of SWSD. Future research should aim to explore the mechanisms behind these associations and develop strategies to enhance shift work tolerance among night shift workers.

Global prevalence of excessive daytime sleepiness among nurses: A systematic review and meta-analysis

BACKGROUND

Nurses face significant risks of excessive daytime sleepiness (EDS), which adversely affects workplace safety and productivity. Yet, the extent of EDS in this workforce remains inadequately characterized.

AIM

The aims of this systematic review were to assess the pooled prevalence of EDS among nurses.

METHODOLOGY

We systematically searched PubMed, Embase, Scopus, and ISI Web of Science for observational studies reporting the prevalence of EDS, as measured by the Epworth Sleepiness Scale (ESS), from database inception to May 1, 2024, with no language restrictions. Study quality was evaluated using JBI's critical appraisal tool. Pooled estimates were calculated through random-effects meta-analysis, with subgroup and meta-regression analyses assessing associations between EDS prevalence and study-level factors. Linear regression modeling was used to assess time trends. This study was registered with PROSPERO (CRD42024535109).

RESULTS

We included 36 unique studies encompassing 2677 nurses from 20 countries. EDS occurred in 14.0%-55.6% of nurses. The results of the meta-analysis showed a pooled prevalence of EDS of 32.2% (95% confidence interval [CI]: 28.5-36.1; I2 = 92.6). Prevalence estimate did not vary substantially in terms of study-level data (i.e., region, country income, pre/post covid era, hospital type, proportion of female nurse, average nursing experience, or proportion of married nurses). The prevalence of EDS in nurses has remained unchanged over time.

CONCLUSIONS

This meta-analysis identifies a high global prevalence of EDS among nurses, affecting nearly one-third of this workforce. The findings underscore the urgent need for targeted interventions to mitigate EDS across diverse geographic and economic contexts.

IMPLICATION FOR NURSING AND NURSING POLICY

This study highlights the pervasive issue of EDS among nurses worldwide, necessitating comprehensive strategies to address this challenge across all regions, income levels, hospital settings, and demographic groups.

Factors Associated with Workplace Injuries Among Shift Work Nurses: A Cross-Sectional Study in an Ecuadorian Sample

Background/Objectives: Shift work schedules and mental and physical workloads affect the sleep homeostasis of nurses, increasing the risk of occupational injuries. This study aimed to investigate the relationship between sleep disturbances caused by shift schedules and the occurrence of needlestick and sharps injuries (NSIs) among nurses, considering significant worker and occupational factors. Methods: A total of 348 nurses from five hospitals of Santiago de Guayaquil, Ecuador, participated in this cross-sectional survey. Data on sociodemographic and occupational characteristics, work schedules, and NSI incidents during the previous six months were collected. Emotional status, sleepiness, and insomnia symptoms were assessed using validated questionnaires. Additionally, nurses with night shifts (fixed or rotating) were specifically assessed to estimate the relationship between NSIs and insomnia or sleepiness symptoms related to these types of shift work using logistic regression analyses. Results: Nurses whose schedule included night shifts showed a higher prevalence of NSIs than those with other shifts (33.2% vs. 29.0%; p < 0.05). High levels of depression, anxiety, and stress were associated with having had an NSI in the previous six months. Logistic regression showed that female sex (adjusted odds ratio, aOR 4.62, 95% CI: 1.65-12.97), less experience in the current clinical setting (aOR 3.12, 95% CI: 1.46-6.57), the use of psychotropic drugs (aOR 4.46, 95% CI: 1.51-13.17), and insomnia and sleepiness symptoms due to shift work (aOR 2.61, 95% CI: 1.15-5.91) increased NSI risk among nurses with night shifts. Conclusions: There is an acute need to explore the complex relationship between sleep troubles linked to shift work schedules, occupational factors, and the risk of occupational injuries and propose preventive strategies for enhancing nurses' sleep health and workplace safety.

Better sleep hygiene is associated with better sleep health in mining shift workers in Australia

Australia's mine sites are largely situated in remote locations and operate around the clock. Many shift workers fly to site, where they work 12-hr shifts and sleep in camp accommodation before they return home for the period rostered off work. Mining shift workers experience poor sleep, yet limited research is available on contributing factors. This study investigated, for the first time, the relationship between the sleep health and sleep hygiene in this population. A survey was disseminated to shift workers in the mining industry, utilising a cross-sectional study design. The Sleep Health Index and Sleep Hygiene Index questionnaires were used to evaluate their sleep health and sleep hygiene, respectively. In total, 470 shift workers (mean age [years]: 39 ± 12, mean body mass index [kg m-2]: 28 ± 5) were included, which involved 132 females. Average scores for the Sleep Health Index and Sleep Hygiene Index were 76 ± 15 and 30 ± 7, respectively. Better sleep health was observed in shift workers with better sleep hygiene (β = -0.52, SE = 0.09 [-0.71, -0.34], p < 0.001). Differences in Sleep Health Index scores were found for individual Sleep Hygiene Index items related to "sleep regularity", "sleep environment", "mental health" and "time in bed extension". However, no differences in Sleep Health Index scores were found for items related to "caffeine, alcohol or nicotine consumption" or "exercise" close to bedtime and "bedtime activities" (p > 0.05 for all). These findings demonstrate a relationship between sleep hygiene and sleep health; therefore, it may be possible to improve the sleep of shift workers by improving their sleep hygiene.

Behavioural therapy for shift work disorder improves shift workers' sleep, sleepiness and mental health: A pilot randomised control trial

The present study evaluates the efficacy of behavioural therapy adapted for shift work disorder with a randomised control design in a healthcare population. Forty-three night shift workers (m. age: 34 years; 77% women) experiencing shift work disorder were randomised to either the behavioural therapy for shift work disorder (BT-SWD) or a waiting-list control group offered after the waiting period. Participants completed questionnaires on insomnia, sleepiness and mental health pre- and post-treatment, pre- and post-waiting, and at follow-up, and a sleep diary. As night shift workers alternate between sleeping during the day after their night shifts and transitioning to nighttime sleep on days off, insomnia severity and sleep variables were analysed for daytime and nighttime sleep. The BT-SWD involved sleep restriction therapy, stimulus control and fixed sleep periods in the dark. Statistical analyses were performed under intent-to-treat and per-protocol approaches. Repeated-measures two-way ANCOVA analysis, controlling for age, sex and pre-treatment daytime total sleep time, was performed with Bonferroni corrections, and between-group effect sizes computed. Fourteen participants dropped out after randomisation. Under the intent-to-treat analysis, BT-SWD participants had a significant greater decrease in daytime insomnia severity and an increase in daytime total sleep time at post-treatment than the control group, with large between-group effect sizes (-1.25 and 0.89). These corresponding results were also significant with large effect sizes under the per-protocol analysis. Sleepiness, anxiety and depression levels improved at post-treatment and maintained at follow-up when the BT-SWD treated controls were added to the BT-SWD group. The behavioural therapy for shift work disorder can be used to improve the sleep and mental health of healthcare night workers.

Digital cognitive behavioural therapy for insomnia reduces insomnia in nurses suffering from shift work disorder: A randomised-controlled pilot trial

Insomnia is a primary symptom of shift work disorder, yet it remains undertreated. This randomised-controlled pilot trial examined the efficacy of a digital, guided cognitive behavioural therapy for insomnia adapted to shift work (SleepCare) in nurses with shift work disorder. The hypothesis was that SleepCare reduces insomnia severity compared with a waitlist control condition. A total of 46 unmedicated nurses suffering from shift work disorder with insomnia (age: 39.7 ± 12.1 years; 80.4% female) were randomised to the SleepCare group or the waitlist control group. The primary outcome measure was the Insomnia Severity Index. Other questionnaires on sleep, mental health and occupational functioning, sleep diary data and actigraphy data were analysed as secondary outcomes. Assessments were conducted before (T0), after the intervention/waitlist period (T1), and 6 months after treatment completion (T2). The SleepCare group showed a significant reduction in insomnia severity from T0 to T1 compared with the control condition (β = -4.73, SE = 1.12, p < 0.001). Significant improvements were observed in sleepiness, dysfunctional beliefs about sleep, pre-sleep arousal, sleep effort, self-reported sleep efficiency and sleep onset latency. No significant effect was found in actigraphy data. Depressive and anxiety symptoms, cognitive irritation and work ability improved significantly. Overall, satisfaction and engagement with the intervention was high. SleepCare improved insomnia severity, sleep, mental health and occupational functioning. This is the first randomised-controlled trial investigating the efficacy of digital cognitive behavioural therapy for insomnia in a population suffering from shift work disorder with insomnia. Future research should further explore these effects with larger sample sizes and active control conditions.

Exposing 24-hour cycles in bile acids of male humans

Bile acids are trans-genomic molecules arising from the concerted metabolism of the human host and the intestinal microbiota and are important for digestion, energy homeostasis and metabolic regulation. While diurnal variation has been demonstrated in the enterohepatic circulation and the gut microbiota, existing human data are poorly resolved, and the influence of the host circadian system has not been determined. Using entrained laboratory protocols, we demonstrate robust daily rhythms in the circulating bile acid pool in healthy male participants. We identify temporal relationships between bile acids and plasma lipids and show that these relationships are lost following sleep deprivation. We also highlight that bile acid rhythmicity is predominantly lost when environmental timing cues are held constant. Here we show that the environment is a stronger determinant of these temporal dynamics than the intrinsic circadian system of the host. This has significance for the intimate relationship between circadian timing and metabolism.

Night Shift Work and Sleep Experiences in Older Night Shift Nurses

BACKGROUND

Working at night leads to misalignment between the biological clock and the work/sleep schedule, resulting in sleepiness and impaired performance during the night shift and poor quality, shortened sleep during the day; this is greatly impaired in older individuals.

OBJECTIVE

To describe night work and sleep experiences from the perspective of older (aged 50-65) nurses.

METHODS

Seven virtual focus groups were formed comprising 19 older nurses who worked regular 8-hour night shifts (at least 6 consecutive hours between midnight and 6 am) to learn about their shift work and sleep experiences. Two facilitators and 2 research assistants independently reviewed and coded the transcripts using qualitative content analysis.

RESULTS

Nine themes were identified in 3 domains: (a) night shift challenges and difficulties, including first night shift is most difficult; never feel rested working nights; and personal health concerns and benefits from working nights; (b) sleep challenges and difficulties, including inconsistent sleep timing when switching between nights and days; extended (24+ hours) time awake before and after consecutive nights; difficulty maintaining long and sound daytime sleep; and napping before night shifts for better performance; and (c) family and social challenges and support, including childcare, family, personal obligations, and social activities affect sleep; aging of self and children influences sleep and prioritization of sleep.

CONCLUSIONS

The findings help understand challenges and struggles to obtain adequate sleep and safe work performance in older night shift nurses. These insignts are critical for designing and implementing feasible and acceptable interventions to improve sleep in this high-risk occupational group.

Association of night-shift work with gambling and problem gambling among workers in Japan: A nationwide cross-sectional study

BACKGROUND AND AIMS

Night-shift work disturbs sleep and is associated with poor health conditions among workers. We aimed to investigate the association between night-shift work and gambling among workers and the association between night-shift work and problem gambling in working and gambling participants.

METHODS

This cross-sectional study used data from an online survey conducted between February 6 and 27, 2023 in Japan. A total of 21,134 workers participated in this study, including 9,739 respondents who had gambled in the past year. We estimated the association between night-shift work and gambling among workers and the association between night-shift work and problem gambling among those who gambled at the survey. We defined problem gambling as a score ≥ 8 on the Problem Gambling Severity Index. All estimates were weighted using a nationally representative survey in Japan. We fitted multivariable weighted logistic regression models after adjusting for 14 confounders.

RESULTS

The weighted prevalence of gambling among non-night and night-shift workers was 42.1 % and 55.4 %, respectively. When focusing on workers gambling in the survey, the prevalence of problem gambling among non-night and night-shift workers was 8.8 % and 24.2 %, respectively. The weighted multivariable logistic regression analyses showed that night-shift work was associated with gambling participation among workers (adjusted odds ratio [aOR], 1.39, 95 % confidence interval [CI] 1.25-1.53, p < 0.001). In addition, night-shift work was associated with problem gambling among those who gambled (aOR 1.94, 95 % CI 1.57-2.40, p < 0.001).

CONCLUSIONS

Night-shift work was associated with gambling among workers and with problem gambling among those who gambled.

A latent profile analysis of shift work tolerance among Chinese male sailors during a prolonged non-24-h rotating shift schedule at sea

Shift work tolerance (SWT) refers to the ability to adapt to shift work without significant adverse consequences. The present study aimed to examine the individual differences in SWT and their predictors and outcomes. Latent profile analyses were conducted using cross-sectional data collected form 448 Chinese male sailors who experienced a prolonged (>30 d) non-24-h rotating shift schedule at sea. Depression, anxiety, sleep disturbance, fatigue, domestic disruption, job satisfaction, work engagement, digestive and cardiovascular symptoms were included as indicators of SWT. The results showed that there existed 2 latent profiles of SWT named as High SWT group and Low SWT group. High SWT group was characterized by low levels on all negative bio-psycho-social outcomes but high levels of work engagement and job satisfaction, while Low SWT group exhibited completely opposite characteristics compared to High SWT group. The level of hardiness could predict profile membership that those with higher level of hardiness were more likely to belong to High SWT group. However, there were no significant differences observed in job performance between two groups. In conclusion, hardiness can serve as a predictor of personnel selection for shift work and hardiness-based intervention programs should be encouraged among the shift workers.

Significance of Melatonin in the Regulation of Circadian Rhythms and Disease Management

Melatonin, the 'hormone of darkness' is a neuronal hormone secreted by the pineal gland and other extra pineal sites. Responsible for the circadian rhythm and seasonal behaviour of vertebrates and mammals, melatonin is responsible for regulating various physiological conditions and the maintenance of sleep, body weight and the neuronal activities of the ocular sites. With its unique amphiphilic structure, melatonin can cross the cellular barriers and elucidate its activities in the subcellular components, including mitochondria. Melatonin is a potential scavenger of oxygen and nitrogen-reactive species and can directly obliterate the ROS and RNS by a receptor-independent mechanism. It can also regulate the pro- and anti-inflammatory cytokines in various pathological conditions and exhibit therapeutic activities against neurodegenerative, psychiatric disorders and cancer. Melatonin is also found to show its effects on major organs, particularly the brain, liver and heart, and also imparts a role in the modulation of the immune system. Thus, melatonin is a multifaceted candidate with immense therapeutic potential and is still considered an effective supplement on various therapies. This is primarily due to rectification of aberrant circadian rhythm by improvement of sleep quality associated with risk development of neurodegenerative, cognitive, cardiovascular and other metabolic disorders, thereby enhancing the quality of life.

Mixed shift rotations, sleep, burnout and well-being in professions similar to radiographers: A systematic review

INTRODUCTION

Delivering 24 h healthcare requires rotational shift work from doctors and the medical imaging team, while contributing to safe and timely care of patients. Additional service pressure and staff shortfall leads to workload pressures, adjusted shift patterns and risk of burnout. Evidence should be sought to the effects of this work on staff.

METHODS

This systematic review followed PRISMA reporting guidelines, using a convergent mixed methods approach according to Guidance from Joanna Briggs International. Quantitative trends and results were qualified in order to thematically analyse in conjunction with qualitative data and discussed together in context. Following initial searching, returned articles were screened by title and abstract. A team of 3 reviewers undertook blinded critical appraisal of those suitable, with quality assurance from a 4th team member. Papers passing a threshold of 75% on JBI appraisal tools were accepted for synthesis. Data extraction of appropriate articles retrieved was undertaken in parallel.

RESULTS

Following screening and critical appraisal, 13 studies were returned focusing exclusively on Non Consultant Doctors. No studies investigated diagnostic radiographers. 85% (n = 11) reported negative association between shift work and the three themes of sleep/fatigue, burnout and wellbeing: including after the introduction of shift pattern control or adjusted shift patterns. The remainder showed no change, or any improvement nullified by countermeasures to maintain service delivery.

CONCLUSION

Current working practices and shift plans in the target population showed detrimental effects on the participants - this can be suggested that Diagnostic Radiographers may suffer fatigue, burnout and poor mental health from stretched shift working patterns.

IMPLICATIONS FOR PRACTICE

Further study into the effects of shift work on Diagnostic Radiographers and other allied health professionals is indicated - relating to the above themes in the context of errors and patient safety. Additional research into Non Consultant Doctors, shift work effects and the context of wider service delivery required; with suitable interventions and education to maximise understanding of legal working practices, monitoring and self-management of symptoms.

Environmental circadian disruption re-writes liver circadian proteomes

Circadian gene expression is fundamental to the establishment and functions of the circadian clock, a cell-autonomous and evolutionary-conserved timing system. Yet, how it is affected by environmental-circadian disruption (ECD) such as shiftwork and jetlag are ill-defined. Here, we provided a comprehensive and comparative description of male liver circadian gene expression, encompassing transcriptomes, whole-cell proteomes and nuclear proteomes, under normal and after ECD conditions. Under both conditions, post-translation, rather than transcription, is the dominant contributor to circadian functional outputs. After ECD, post-transcriptional and post-translational processes are the major contributors to whole-cell or nuclear circadian proteome, respectively. Furthermore, ECD re-writes the rhythmicity of 64% transcriptome, 98% whole-cell proteome and 95% nuclear proteome. The re-writing, which is associated with changes of circadian regulatory cis-elements, RNA-processing and protein localization, diminishes circadian regulation of fat and carbohydrate metabolism and persists after one week of ECD-recovery.

Online Games and Cognitive Distortions: A Comparative Analysis in Students with and without Disabilities

Online games have experienced significant growth in recent years, with gaming becoming a popular form of entertainment for people of all ages. However, their impact on cognition, especially among vulnerable groups such as students with disabilities, is a topic that requires deeper exploration. The objectives of this study are twofold: firstly, to understand the typology of risk players (non-risk players, players with problems, and pathological players); and secondly, to compare cognitive distortions among students with problematic profiles. Both objectives will be analyzed based on the presence or absence of disability. A total of 704 students from various Spanish universities (135 with disabilities and 569 without disabilities), aged between 18 and 38, participated in the study by completing the Gamblers Belief Questionnaire (GBQ), aimed at measuring cognitive distortions related to gambling problems, as well as the Massachusetts Gambling Screen questionnaire, aimed at measuring gambling addiction. The results indicate a higher percentage of students with disabilities showing a greater risk profile for addiction. Additionally, this group of students exhibits more cognitive distortions. These findings underscore the need for a comprehensive approach to addressing online gaming addiction and cognitive distortions among university students, with and without disabilities. Preventive measures are necessary, such as education on responsible technology use and the promotion of alternative activities. Moreover, specific intervention strategies need to be developed, including access to psychological health services for this student population.

The influence of shift work: A bibliometric analysis of research progress and frontiers on health effects

Shift work has been found to disrupt the circadian system, leading to negative health effects. The objective of this study was to assess the progress and frontiers in research on the health-related influence of shift work. The study analyzed 3,696 data points from Web of Science, using the bibliometric software CiteSpace to visualize and analyze the field. The results showed a steady increase in annual publications, particularly in the last 5 years, with a rapid increase in publications from China. The United States contributed the most to the number of publications and worldwide collaborations. The most prolific institution and author were the Brigham and Women's Hospital and Professor Bjorn Bjorvatn, respectively. The Journal of Chronobiology International ranked at the top and focused primarily on shift worker research. In the first decade of study, the primary focus was on the associations between shift work and cardiovascular disease and metabolic disorders. Over time, research on the health effects of shift work has expanded to include cancer and mental health, with subsequent studies investigating molecular mechanisms. This study provides a comprehensive and intuitive analysis of the negative health impacts of shift work. It highlights existing research hotspots and provides a roadmap for future studies. Further research is needed to explore the adverse health consequences and related mechanisms of shift work exposure, as well as interventions to mitigate its health effects.

Link between circadian rhythm and benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS)

BACKGROUND

Benign prostatic hyperplasia (BPH) is the most common urologic disease in aging males, affecting 50% of men over 50 and up to 80% of men over 80 years old. Its negative impact on health-related quality of life implores further investigation into its risk factors and strategies for effective management. Although the exact molecular mechanisms underlying pathophysiological onset of BPH are poorly defined, the current hypothesized contributors to BPH and lower urinary tract symptoms (LUTS) include aging, inflammation, metabolic syndrome, and hormonal changes. These processes are indirectly influenced by circadian rhythm disruption. In this article, we review the recent evidence on the potential association of light changes/circadian rhythm disruption and the onset of BPH and impact on treatment.

METHODS

A narrative literature review was conducted using PubMed and Google Scholar to identify supporting evidence. The articles referenced ranged from 1975 to 2023.

RESULTS

A clear relationship between BPH/LUTS and circadian rhythm disruption is yet to be established. However, common mediators influence both diseases, including proinflammatory states, metabolic syndrome, and hormonal regulation that can be asserted to circadian disruption. Some studies have identified a possible relationship between general LUTS and sleep disturbance, but little research has been done on the medical management of these diseases and how circadian rhythm disruption further affects treatment outcomes.

CONCLUSIONS

There is evidence to implicate a relationship between BPH/LUTS and circadian rhythm disruptions. However, there is scarce literature on potential specific link in medical management of the disease and treatment outcomes with circadian rhythm disruption. Further study is warranted to provide BPH patients with insights into circadian rhythm directed appropriate interventions.

Chronodisruption and Gut Microbiota: Triggering Glycemic Imbalance in People with Type 2 Diabetes

The desynchronization of physiological and behavioral mechanisms influences the gut microbiota and eating behavior in mammals, as shown in both rodents and humans, leading to the development of pathologies such as Type 2 diabetes (T2D), obesity, and metabolic syndrome. Recent studies propose resynchronization as a key input controlling metabolic cycles and contributing to reducing the risk of suffering some chronic diseases such as diabetes, obesity, or metabolic syndrome. In this analytical review, we present an overview of how desynchronization and its implications for the gut microbiome make people vulnerable to intestinal dysbiosis and consequent chronic diseases. In particular, we explore the eubiosis-dysbiosis phenomenon and, finally, propose some topics aimed at addressing chronotherapy as a key strategy in the prevention of chronic diseases.

Diagnosis and management of sleep disorders in shift workers, with patient informed solutions to improve health services research and practice

BACKGROUND

The combination of shift work and an unmanaged sleep disorder carries health and safety risks. Yet, diagnosis rates for sleep disorders are low in shift workers. The aim of this study was to understand the experience of sleep disorder diagnosis and treatment in shift workers, and consider patient informed solutions to improve access to health services.

METHODS

Semi-structured interviews were conducted with 16 Australian shift workers with a diagnosed sleep disorder. Patient journey mapping and reflexive thematic analysis were used to understand diagnosis and management experiences.

RESULTS

There were highly variable experiences with diagnosis and management, often taking >5 years to seek help from a health care provider (HCP) after noticing symptoms of a sleep disorder. Three themes were constructed, including 'the cause of the problem', 'prioritising work', and '(dis)satisfaction and (dis)connection'. Extent of patient and HCP awareness of sleep disorders, and a prevailing attitude of shift work being 'the problem' impacted diagnosis, as did organisational needs (including rostering, which had both positive and negative influences on help seeking). Relationships with HCPs were important, and living on non-standard time was both a barrier and an enabler to sleep disorder care. Participants identified the need for education and awareness, prompts and easy access to screening and referral pathways, and tailored models of care.

CONCLUSION

Education and awareness initiatives for shift workers, their employers and HCPs, together with development of a model of care for shift workers with sleep disorders may address some of the unique barriers to diagnosis and management.

Shift work is associated with extensively disordered sleep, especially when working nights

Background

Shift work is generally associated with working and sleeping out of phase with the endogenous, circadian sleep-wake cycle. This exerts detrimental effects on sleep health. The present study aimed at evaluating the presence of short and long sleep as well as sleep disorders within a broad range of shift work schedules and elucidating the role of sociodemographic factors therein.

Methods

A large dataset containing information on sleep was collected through advertisement in a Belgium newspaper (De Standaard). Adult, working individuals were selected (n = 37,662) and categorized based on their work schedule (regular day, early morning, evening, night, and rotating shift). In this cross-sectional study, prevalence rates of short sleep (≤6 h), long sleep (≥9 h) and sleep disorders (screened with Holland Sleep Disorders Questionnaire), and associations between these sleep variables and sociodemographics (age, sex, education, living companion(s)) were analyzed using binominal logistic regression analyses.

Results

In the total sample all sociodemographic factors affected prevalences of short, long and disordered sleep, consistent with previous studies. Compared to day workers, shift workers more frequently reported short sleep, most prominently night workers (26 vs. 50%) (p < 0.001). Furthermore, all sleep disorders as well as sleep disorder comorbidity were more common in shift workers, again most pronounced in night workers (all p < 0.05). In night shift workers the level of education had the strongest associations with disturbed sleep with a two-fold higher prevalence of short and disordered sleep in low relative to academic educated groups (all p < 0.02).

Conclusion

Shift work is related not only to curtailed sleep and shift work disorder, but also to a plethora of sleep disorders, including insomnia, sleep-related breathing disorders and sleep-related movement disorders. Our findings imply that education on coping strategies may be especially important for young and/or lower educated shift workers.

Rotating Night Shift Work, Sleep, and Thyroid Cancer Risk in the Nurses' Health Study 2

Night shift work has been associated with breast, prostate, and colorectal cancer, but evidence on other types of cancer is limited. We prospectively evaluated the association of rotating night shift work, sleep duration, and sleep difficulty with thyroid cancer risk in the Nurses' Health Study 2 (NHS2). We assessed rotating night shift work duration (years) at baseline and throughout follow-up (1989-2015) and sleep characteristics in 2001. Cox proportional hazard models, adjusted for potential confounders, were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for (a) shift work duration, (b) sleep duration, and (c) difficulty falling or staying asleep. We stratified the analyses of night shift work by sleep duration and sleep difficulty. Over 26 years of follow-up, 588 incident cases were identified among 114,534 women in the NHS2 cohort. We observed no association between night shift work and the risk of thyroid cancer. Difficulty falling or staying asleep was suggestively associated with a higher incidence of thyroid cancer when reported sometimes (HR 1.26, 95% CI 0.95, 1.66) and all or most of the time (HR 1.35, 95% CI 1.00, 1.81). Night shift workers (10+ years) with sleep difficulty all or most of the time (HR 1.47; 0.58-3.73) or with >7 h of sleep duration (HR 2.17; 95% CI, 1.21-3.92) had a higher risk of thyroid cancer. We found modest evidence for an increased risk of thyroid cancer in relation to sleep difficulty, which was more pronounced among night shift workers.

The impact of meaning in life and professional happiness on the turnover intention of health care workers: a cross-sectional study from China

INTRODUCTION

The turnover and shortage of health care workers (HCWs) have been a worldwide problem for healthcare organizations. The primary aim of this study was to identify the factors influencing the intention of Chinese HCWs to leave their job, especially meaning in life and professional happiness.

METHODS

This observational cross-sectional study, conducted among 1125 full-time HCWs, assessed demographic variables, meaning in life, professional happiness, and turnover intention by a survey. The survey was distributed to HCWs in three tertiary hospitals. The data were analyzed by T-tests, ANOVA, Kruskal-Wallis tests and hierarchical linear regression model.

RESULTS

There were statistically significant differences in turnover intention of HCWs by gender, age, role, educational level, years in practice, and number of monthly night shifts. HCWs' meaning in life and professional happiness were negatively associated with the turnover intention. Furthermore, after controlling for other factors, meaning in life explained 3.7% of the turnover intention and professional happiness explained 13.4%.

CONCLUSION

In our study, positive psychological factors were related to turnover intentions. Professional happiness was the strongest predictor. Thus, health human resource managers should foster positive psychology among HCWs to reduce their turnover.

Sleep and circadian rhythm disturbance in kidney stone disease: a narrative review

The circadian rhythm generated by circadian clock genes functions as an internal timing system. Since the circadian rhythm controls abundant physiological processes, the circadian rhythm evolved in organisms is salient for adaptation to environmental change. A disturbed circadian rhythm is a trigger for numerous pathological events. Recently, accumulated data have indicated that kidney stone disease (KSD) is related to circadian rhythm disturbance. However, the mechanism between them has not been fully elucidated. In this narrative review, we summarized existing evidence to illustrate the possible association between circadian rhythm disturbance and KSD based on the epidemiological studies and risk factors that are linked to circadian rhythm disturbance and discuss some chronotherapies for KSD. In summary, KSD is associated with systemic disorders. Metabolic syndrome, inflammatory bowel disease, and microbiome dysbiosis are the major risk factors supported by sufficient data to cause KSD in patients with circadian rhythm disturbance, while others including hypertension, vitamin D deficiency, parathyroid gland dysfunction, and renal tubular damage/dysfunction need further investigation. Then, some chronotherapies for KSD were confirmed to be effective, but the molecular mechanism is still unclear.

Circadian misalignment alters resting-state functional connectivity of the salience network in rotating shift workers

STUDY OBJECTIVES

This study compared resting-state functional connectivity (rsFC) of the salience network (SN) between rotating shift workers (RSWs) and controls. Furthermore, we examined whether rsFC of the SN was correlated with sleep, emotion, cognition, and attention.

METHODS

The 60 RSWs and 57 controls enrolled in this study completed self-report questionnaires and sleep diaries to assess subjective sleep quality, and polysomnography and actigraphy to evaluate objective sleep and 24-hour rest-activity rhythm parameters. The participants also underwent resting-state functional magnetic resonance imaging and structural T1 scans. We performed a seed-based rsFC analysis of the SN using the anterior cingulate cortex (ACC) and anterior insula (AI) as seed regions. Furthermore, AI and ACC rsFC were compared in RSWs and controls, and we analyzed correlations between rsFC and variables of interest showing significant group differences.

RESULTS

Compared with controls, RSWs showed reduced rsFC between the ACC and right insula, and increased rsFC of the ACC with the left occipital lobe and right superior frontal gyrus extending to the supplementary motor area (SFG/SMA). Moreover, RSWs showed reduced rsFC between the right AI and right superior parietal lobule (SPL). Finally, rsFC between the ACC and right AI was correlated with 24-hour rest-activity rhythmicity.

CONCLUSIONS

Although RSWs did not show sleep disturbance, emotional distress, cognitive impairment, or attention deficits, alterations of right insula, left occipital lobe, right SFG/SMA, and right SPL rsFC in the SN indicate that impairments in salience detection and top-down attentional control may emerge in shift workers over time.

Recovery from shift work

One fifth of today's workforce is engaged in shift work and exposed to various mental and physical health risks including shift work disorder. Efficiently recovering from shift work through physical and mental interventions allows us to mitigate negative effects on health, enables a better work-life balance and enhances our overall wellbeing. The aim of this review is to provide a state-of-the-art overview of the available literature. The role of sleep timing and naps, light therapy and psychotherapy, diet and exercise in recovery from shift work is presented here. We further review the impact of shift schedules and social support on post-shift unwinding.

Association between shift work and the risk of hypothyroidism in adult male workers in Korea: a cohort study

Background

Shift work has been reported to have several harmful effects on the human body. However, a small number of studies have evaluated the association between shift work and adverse effects on the thyroid. In our longitudinal study, we examined the causal association between shift work and the risk of hypothyroidism.

Methods

A Kangbuk Samsung Cohort Study was conducted on 112,648 men without thyroid disease at baseline who were followed up at least once between 2012 and 2019. Shift work status and shift schedule types were categorized using standardized questionnaires. Hypothyroidism was defined using the reference ranges of serum thyroid-stimulating hormones and free thyroxine levels. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident hypothyroidism were estimated using Cox proportional hazards regression analyses with the daytime work group as the reference.

Results

During the 501,237 person-years of follow-up, there were 6,306 incident cases of hypothyroidism (incidence density, 1.26 per 100 person-years). The multivariable-adjusted HR of incident hypothyroidism for the shift work total group that included all shifts compared with the daytime work group was 1.27 (95% CI: 1.15-1.40). For the fixed evening, fixed night, rotating shift, and other shift workers, the multivariable-adjusted HRs (95% CI) were 1.11 (0.76-1.61), 2.18 (1.20-3.93), 1.39 (1.23-1.56), and 1.00 (0.82-1.22), respectively. In subgroup analyses by age, the association between shift work and hypothyroidism was more pronounced in younger participants (< 40 years; HR: 1.31; 95% CI: 1.16-1.47).

Conclusions

Our large-scale cohort study showed an association between shift work and the incidence of hypothyroidism, especially in younger workers with night shifts.

Interventions to improve the sleep of nurses: A systematic review

Nurses are at a high risk for short sleep duration and poor sleep quality due to irregular work schedules and high occupational stress. Considering the effect of nurses' sleep on the safety and health of themselves and their patients, it is important to promote healthy sleep for nurses. We sought to synthesize the published experimental and quasi-experimental studies that address interventions to improve sleep in nurses. A systematic search was conducted for studies published in English up until May 15, 2023, using the databases PubMed, CINAHL, Academic Search Ultimate, and PsycINFO. In total, 38 articles were included, covering 22 experimental and 16 quasi-experimental studies with sample sizes ranging from 9 to 207. Studies were assessed using the Cochrane Risk of Bias tool and considered as low to medium quality. Thirty-six of the 38 studies reported positive findings for at least one sleep outcome. Intervention types included aroma therapy, dietary supplements, cognitive behavioral therapy, light therapy, mind-body therapy, sleep education, exercise, napping, shift schedule modification, and multicomponent intervention, all of which showed moderate effectiveness in promoting sleep outcomes of nurses. Comparing and contrasting studies on specific interventions for improving sleep in nurses is sparse and often equivocal. With the variations of research methodology and outcome measures, it is difficult to make a conclusion about each intervention's effectiveness on specific sleep outcomes. Additional high-quality research, including randomized controlled trials, is needed to evaluate strategies for improving sleep in this unique, safety-sensitive occupational group.

Impact of Simulated Rotating Shift Work on Mammary Tumor Development in the p53R270H©/+WAPCre Mouse Model for Breast Cancer

Epidemiological studies associate night shift work with increased breast cancer risk. However, the underlying mechanisms are not clearly understood. To better understand these mechanisms, animal models that mimic the human situation of different aspects of shift work are needed. In this study, we used "timed sleep restriction" (TSR) cages to simulate clockwise and counterclockwise rotating shift work schedules and investigated predicted sleep patterns and mammary tumor development in breast tumor-prone female p53R270H©/+WAPCre mice. We show that TSR cages are effective in disturbing normal activity and estimated sleep patterns. Although circadian rhythms were not shifted, we observed effects of the rotating schedules on sleep timing and sleep duration. Sleep loss during a simulated shift was partly compensated after the shift and also partly during the free days. No effects were observed on body weight gain and latency time of breast cancer development. In summary, our study shows that the TSR cages can be used to model shift work in mice and affect patterns of activity and sleep. The effect of disturbing sleep patterns on carcinogenesis needs to be further investigated.

Novel Roles for the Transcriptional Repressor E4BP4 in Both Cardiac Physiology and Pathophysiology

Circadian clocks temporally orchestrate biological processes critical for cellular/organ function. For example, the cardiomyocyte circadian clock modulates cardiac metabolism, signaling, and electrophysiology over the course of the day, such that, disruption of the clock leads to age-onset cardiomyopathy (through unknown mechanisms). Here, we report that genetic disruption of the cardiomyocyte clock results in chronic induction of the transcriptional repressor E4BP4. Importantly, E4BP4 deletion prevents age-onset cardiomyopathy following clock disruption. These studies also indicate that E4BP4 regulates both cardiac metabolism (eg, fatty acid oxidation) and electrophysiology (eg, QT interval). Collectively, these studies reveal that E4BP4 is a novel regulator of both cardiac physiology and pathophysiology.

Sleep quality and sleep-related issues in industrial workers: a global meta-analysis

Objectives. Sleep-related issues are important health issues. This study aimed to investigate the global prevalence of sleep-related issues in industrial workers. Methods. A syntax of keywords was used to search the PubMed, Web of Science and Scopus databases. The search time was limited to articles published until September 2020, and the search range was in English. Events and samples were extracted for each study to calculate the prevalence. For all subgroups, events and samples were extracted to calculate the results of the subgroups. The random-effects method was used in the analysis. Heterogeneity was examined at the levels of all analyses. Results. Forty-eight articles were included in the analysis as eligible studies. Sleep-related issues have 30% prevalence in the 95% confidence interval (CI) [25, 35%]. The prevalence of sleep-related issues in men was 38%, 95% CI [31, 45%] and in women was 32%, 95% CI [14, 50%]. The prevalence of poor sleep quality, insomnia, sleep duration <7 h, snoring and sleepiness was 36, 22, 37, 29 and 10%, respectively. Conclusions. Sleep-related issues have a high prevalence in industrial workers, and the cause of these differences needs to be addressed and increasing insights provided to prevent and treat sleep disorders.

Investigating the effectiveness of employing clinical faculty members in the shift work system during the Covid-19 pandemic in Iran: A cross-sectional study

Introduction

Having an accurate attitude about shift work and choosing the right people to work in the shift work system increases organizational productivity and improves the employees' life quality. Consequently, the current research investigates the effectiveness of employing clinical faculty members in the shift work system during the Covid-19 pandemic.

Materials and Methods

In this descriptive study, 71 Iranian clinical faculty members with a history of shift work (night shift) during the Covid-19 pandemic participated. Circadian Type Inventory (CTI) was used to collect data.

Results

Based on the results of this research (Flexible/Rigid = Mean ± SD = 2.47 ± 18.17) and (Languid/Vigorous = Mean ± SD = 2.89 ± 15.35) which revealed that although clinical faculty members in normal conditions can overcome the feeling of sleepiness due to lack of sleep, they are not flexible and cannot work in the shift work system with the ability to stay awake at unusual times of the day or night. Pearson's correlation coefficient test also showed that as the value of the Languid/Vigorous component increases, the value of the Flexible/Rigid component also increases (r = 0.410). Likewise, there was no significant relationship between the main research variables and demographic characteristics.

Discussion and Conclusion

Clinical faculty members who are simultaneously responsible for the duties of teaching students, research, and treating patients, if they are employed in a shift work system, especially during the pandemic, it may lead to a decrease in the quality of teaching, lack of motivation in research and indifference toward students' affairs, reducing flexibility, inability to update what they have learned in the professional world, increasing medical errors and also reducing their ability to manage the class. Consequently, it is suggested to avoid using them in the shift work systems as much as possible.

Alcohol Mixed with Energy Drinks (AmED) Use among University Students: A Systematic Review and Meta-Analysis

In the last decades, there has been a huge increase in the consumption of both Energy Drinks (EDs) and alcohol and, concurrently, these two trends generated the additional practice of mixing ED with alcohol, known as Alcohol mixed with Energy Drink (AmED). One of the most important group of AmED consumers is represented by young. Indeed, the study population of the researches in this field are mainly represented by college students and the results evidence a great range of negative consequences for health. The purpose of the systematic review was to explore the prevalence of AmED consumption among undergraduate students, together with motivations to their use, adverse effects and health-related behaviors associated to AmEDs use. The review was conducted according to the PRISMA Statement and PubMed, Scopus and Web of Science were interrogated. 42 articles, published from 2008 to 2021, were included in the review. An overall prevalence rate of 37% was estimated for AmEDs use in undergraduates, with geographical differences. Although a decrease in consumption was observed throughout the studied period, a continuous monitoring on this phenomenon is needed for identifying those risk groups that could develop risky behaviors related to AmEDs consumption and provide them targeted educational interventions.

Shift Work Disorder Index: initial validation and psychosocial associations in a sample of nurses

STUDY OBJECTIVES

Shift work is common yet does not always result in Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5)-defined shift work sleep disorder (SWD). This study reports on the reliability and validity of the DSM-5 informed Shift Work Disorder Index (SWDI), the presence of probable SWD in nurses, and demographic, sleep, and psychosocial correlates.

METHODS

Nurses (n = 454) completed the SWDI, psychosocial, and demographic questionnaires. Of the sample, n = 400 completed 14 days of sleep diaries, actigraphy, and additional questionnaires.

RESULTS

The global SWDI demonstrated excellent internal consistency (α = .94), as well as good convergent and divergent validity in the nurse sample. Thirty-one percent of nurses were past-month shift workers, with 14% (ie, 44% of shift workers) having probable SWD based on SWDI. Nurses who worked shift work and/or met SWD criteria were more likely to be younger and unmarried and less likely to have children than day workers and reported greater evening chronotype, insomnia, nightmares, and sleep-related impairment, greater depression, anxiety, posttraumatic stress, and perceived stress symptoms, as well as later and more variable sleep midpoint (actigraphy), shorter sleep duration (actigraphy, diaries), and lower sleep efficiency (diaries).

CONCLUSIONS

The SWDI is an efficient and valid self-report assessment of DSM-5-defined SWD. Shift work and/or SWD were prevalent and associated with worse sleep and psychosocial health, particularly among nurses with probable SWD.

CITATION

Taylor DJ, Dietch JR, Wardle-Pinkston S, et al. Shift Work Disorder Index: initial validation and psychosocial associations in a sample of nurses. J Clin Sleep Med. 2022;18(10):2339-2351.

Circadian rhythms and disorders of the timing of sleep

The daily alternation between sleep and wakefulness is one of the most dominant features of our lives and is a manifestation of the intrinsic 24 h rhythmicity underlying almost every aspect of our physiology. Circadian rhythms are generated by networks of molecular oscillators in the brain and peripheral tissues that interact with environmental and behavioural cycles to promote the occurrence of sleep during the environmental night. This alignment is often disturbed, however, by contemporary changes to our living environments, work or social schedules, patterns of light exposure, and biological factors, with consequences not only for sleep timing but also for our physical and mental health. Characterised by undesirable or irregular timing of sleep and wakefulness, in this Series paper we critically examine the existing categories of circadian rhythm sleep-wake disorders and the role of the circadian system in their development. We emphasise how not all disruption to daily rhythms is driven solely by an underlying circadian disturbance, and take a broader, dimensional approach to explore how circadian rhythms and sleep homoeostasis interact with behavioural and environmental factors. Very few high-quality epidemiological and intervention studies exist, and wider recognition and treatment of sleep timing disorders are currently hindered by a scarcity of accessible and objective tools for quantifying sleep and circadian physiology and environmental variables. We therefore assess emerging wearable technology, transcriptomics, and mathematical modelling approaches that promise to accelerate the integration of our knowledge in sleep and circadian science into improved human health.

SHIFTPLAN: a randomized controlled trial investigating the effects of a multimodal shift-work intervention on drivers' fatigue, sleep, health, and performance parameters

BACKGROUND

Shift work is commonly associated with health problems resulting from circadian misalignment and sleep restriction. About one in three shift workers is affected by insomnia and up to 90% report regular fatigue and/or sleepiness at the workplace. Epidemiological data shows that shift workers are at increased risk of cardiovascular disease, diabetes, obesity, breast cancer, mental-health problems, and shift-work disorder, which conditions typically lead to reduced work performance, processing errors, accidents at work, absenteeism, and reduced quality of life. Given these widespread and debilitating consequences, there is an urgent need for treatments that help improve the sleep, health, and functional performance of the shift-working population. The most common non-pharmacological recommendations are improved scheduling, bright-light exposure, napping, psychoeducation promoting sleep hygiene, and cognitive-behavioral techniques. The objectives of the present study are to investigate the effects of a multimodal shift-work intervention on perceived fatigue, sleepiness, physical and mental health, sleep parameters, and absenteeism.

METHODS

A randomized controlled interventional study comparing the two groups each comprising at least 80 drivers of a public transport company, using self-report questionnaires and health checks completed at intake and after 3 and 6 months following the start of the intervention or waiting-list period. The intervention consists of (a) healthy scheduling taking into account shift-rotation direction and speed, chronotype, resting time, and napping; (b) an education program specifically developed for shift workers; and (c) a dedicated information campaign for shift planners. The primary outcome is symptomatic burden in terms of sleepiness, and the key secondary outcome is symptomatic burden in terms of fatigue. Supplementary secondary outcomes are sleep parameters, absenteeism, general and clinical health, changes in mood, and anxiety.

DISCUSSION

Expected outcomes are significant improvements on all primary and secondary outcome parameters in the intervention group. To our knowledge, ours is the first randomized controlled study to systematically investigate the effects of a multimodal program on multiple health, sleep, and performance parameters in shift workers. Our research also aims at providing evidence-based practice guidelines for healthy scheduling in general and thus contribute to diminishing the serious health and economic burdens associated with shift work overall.

TRIAL REGISTRATION

EDGE registration number: 000339.

CLINICALTRIALS

gov NCT05452096.

Evidence of White Matter Integrity Changes in the Anterior Cingulum Among Shift Workers: A Cross-Sectional Study

Introduction

We investigated the white matter integrity in shift and non-shift workers and its associations with sleep and activity.

Methods

Diffusion tensor imaging (DTI) was performed on 61 shift workers and 31 non-shift workers. Their sleep and activity profiles were assessed using the Pittsburgh Sleep Quality Index (PSQI), sleep diaries, and actigraphy. Fractional anisotropy (FA) (a measure of white matter integrity) was calculated using DTI tractography.

Results

Shift workers exhibited higher FA values in the bilateral anterior cingulum than did non-shift workers. An increased FA in the right anterior cingulum was correlated with poor sleep quality (ie, a high PSQI score) in shift workers. An increased FA in the right anterior cingulum was also correlated with higher actigraphic activity indices (the mesor and M10 indices) in shift workers.

Discussion

The white matter integrity of the anterior cingulum was altered in shift workers, perhaps in association with sleep and activity disturbances.

Mobile phone sleep self-management applications for early start shift workers: A scoping review of the literature

Poor sleep has significant impacts on both mental and physical well-being. This is especially the case for shift workers who rely on good sleep practices to manage the disruption caused by their working conditions. In recent years there has been a proliferation of sleep-focused mobile phone applications, some of which may be suitable for use by shift workers. There is limited evidence however, on whether these applications are sufficient in managing the sleep needs of the early start shift working population (i.e., those whose work schedules begin pre-dawn). This scoping review aims to identify and discuss peer-reviewed literature on mobile sleep applications used by early start shift workers for sleep-self management. Four databases (Scopus, EBSCOhost, CINAHL and PsycInfo) were searched for relevant literature using a pre-determined search string. The initial search using the term early start shift work returned no papers, however a broadened search on shift work in general found 945 papers for title and abstract screening, of which 21 were deemed eligible for full text screening. Two of these papers met the inclusion criteria for this review. The results highlight, firstly, the paucity of research on the use of mobile phone applications for sleep self-management amongst early start shift workers, and secondly, the need for further research on the effectiveness of mobile applications for sleep self-management amongst shift workers in general. A working definition of early start shift work that can be used to stimulate research in this understudied population of shift workers is also proposed.

Sleep and work functioning in nurses undertaking inpatient shifts in a blue-depleted light environment

BACKGROUND

Blue-depleted light environments (BDLEs) may result in beneficial health outcomes for hospital inpatients in some cases. However, less is known about the effects on hospital staff working shifts. This study aimed to explore the effects of a BDLE compared with a standard hospital light environment (STLE) in a naturalistic setting on nurses' functioning during shifts and sleep patterns between shifts.

METHODS

Twenty-five nurses recruited from St. Olavs Hospital in Trondheim, Norway, completed 14 days of actigraphy recordings and self-reported assessments of sleep (e.g., total sleep time/sleep efficiency) and functioning while working shifts (e.g., mood, stress levels/caffeine use) in two different light environments. Additionally, participants were asked to complete several scales and questionnaires to assess the symptoms of medical conditions and mental health conditions and the side effects associated with each light environment.

RESULTS

A multilevel fixed-effects regression model showed a within-subject increase in subjective sleepiness (by 17%) during evening shifts in the BDLE compared with the STLE (p = .034; Cohen's d = 0.49) and an 0.2 increase in number of caffeinated beverages during nightshifts in the STLE compared with the BDLE (p = .027; Cohen's d = 0.37). There were no significant differences on any sleep measures (either based on sleep diary data or actigraphy recordings) nor on self-reported levels of stress or mood across the two conditions. Exploratory between-group analyses of questionnaire data showed that there were no significant differences except that nurses working in the BDLE reported perceiving the lighting as warmer (p = .009) and more relaxing (p = .023) than nurses working in the STLE.

CONCLUSIONS

Overall, there was little evidence that the change in the light environment had any negative impact on nurses' sleep and function, despite some indication of increased evening sleepiness in the BDLE. We recommend further investigations on this topic before BDLEs are implemented as standard solutions in healthcare institutions and propose specific suggestions for designing future large-scale trials and cohort studies.

TRIAL REGISTRATION

The study was registered before data collection was completed on the ISRCTN website ( ISRCTN21603406 ).

Protocol for a systematic review and meta-analysis on the associations between shift work and sickness absence

BACKGROUND

Shift work, i.e., non-standard work hours, has been associated with both short- and long-term sickness absence. However, findings are inconsistent and inconclusive. Thus far, no comprehensive meta-analytic synthesis on the relationship between shift work and sickness absence has been published. The aims of the planned systematic review and meta-analysis are (1) to establish whether shift work is associated with sickness absence, (2) to determine if specific shift work characteristics relate to sickness absence (e.g., length and frequency of spells), and (3) to identify moderating factors affecting the relationship between shift work and sickness absence.

METHODS

Eligible studies will be identified using a predefined search strategy in several electronic databases (MEDLINE, Web of Science, PsychInfo, EMBASE, and ProQuest) and comprise peer-reviewed papers reporting original empirical findings on the association between shift work and sickness absence. Mainly observational studies with cross-sectional, prospective, or retrospective research design and case-control studies will be included. Risk of bias will be assessed using an adapted checklist previously employed to evaluate studies on sickness absence. To carry out the meta-analytic synthesis, a random effects meta-analysis will be conducted using the Comprehensive Meta-Analysis software. The review and meta-analysis will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Heterogeneity will be evaluated by Cochran's Q test and the I² statistics.

DISCUSSION

The review and meta-analysis will be the first to conduct a meta-analytic synthesis of the evidence on the association between exposure to shift work and sickness absence, as well as identify relevant moderators affecting the relationship between shift work and sickness absence. Aggregation of the existing evidence will improve the knowledge on the association between shift work and sickness absence. Such knowledge can be used to guide scheduling of shift work to promote work schedules that are less detrimental to health and contribute to reduced sickness absence and higher work- and leisure-time productivity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022301200.

Shift-work sleep disorder among health care workers at public hospitals, the case of Sidama national regional state, Ethiopia: A multicenter cross-sectional study

Introduction

Shift-work disrupts circadian rhythm, resulting in disturbed sleep time and excessive sleepiness during the work shift. Little is known about shift-work sleep disorder among health care workers in Ethiopia. This study examined the magnitude and associated factors of shift-work sleep disorder among health care workers in Public Hospitals in Sidama National Regional State, Southern Ethiopia.

Methods

An institution-based cross-sectional study was carried out on 398 health care workers selected using a systematic random sampling technique. A self-administered structured questionnaire consisting of insomnia, sleepiness scales and international classification of sleep disorder criteria items was employed. Epi data version 4.6 and Stata 14 were used for data entry and statistical analysis respectively. Binary logistic regression was fitted to determine associated factors and decision for the statistical significance was made at p<0.05 in the multivariable binary logistic regression.

Results

Three hundred and ninety-eight health care workers (female = 53%) were included in the analysis with a response rate of 94.8%. The prevalence of shift-work sleep disorder was 33.67% (95% CI: 29.17%-38.45%). Being married (AOR = 1.88 (1.01–3.28)), three-shift (AOR = 1.078 (1.00–3.16)), ≥11 night shifts per month (AOR = 2.44 (1.36–4.38)), missing nap (AOR = 1.85 (1.04–3.30)), daily sleep time < 7hours (AOR = 1.88 (1.05–3.38)), khat chewing (AOR = 2.98 (1.27–8.09)), alcohol drinking (AOR = 2.6(1.45–4.92)), and cigarette smoking (AOR = 3.32 (1.35–8.14)) were significantly associated with shift-work sleep disorder.

Conclusion

This study showed a high prevalence of shift-work sleep disorder. Two shift schedule, napping, and reduction of substance use might reduce shift-work sleep disorder.

Shift work disorder and the prevalence of help seeking behaviors for sleep concerns in Australia: A descriptive study

Shift work disorder (SWD) is a circadian rhythm sleep-wake disorder, defined by symptoms of insomnia and excessive levels of sleepiness resulting from work that occurs during non-standard hours. Sleep problems are common in shift workers, yet our understanding of help seeking behaviours for sleep in shift workers is limited. The primary aim of this study was to examine the help seeking behaviours of Australian workers who meet criteria for SWD. Of the 448 (46% of sample, n = 964 total) Australian workers reporting non-standard work hours, 10.5% (n = 41) met the criteria for probable shift work disorder (pSWD). Non-standard workers with pSWD did not seek help for sleep problems at higher rates than workers without SWD. Of the small proportion of workers with pSWD who sought help, general practitioners were the most common healthcare professionals for sleep problems. Self-management was common in workers with pSWD, with a high self-reported prevalence of alcohol use (31.7%) as a sleep management strategy, and caffeine consumption (76.9%) as a sleepiness management strategy. The majority of individuals with pSWD reported the mentality of 'accept it and keep going' as a sleepiness management strategy, highlighting a potential barrier to help seeking behaviour in workers with pSWD. These findings provide novel insight into the help seeking behaviours of those with pSWD. There is a need for further research to understand why individuals at risk for SWD are not actively seeking help, and to develop health promotion and intervention strategies to improve help seeking when needed.