Effects of a work schedule with abated quick returns on insomnia, sleepiness and work-related fatigue: Results from a large-scale cluster randomized controlled trial.

STUDY OBJECTIVES: To investigate the effect of a work schedule with abated quick returns (i.e., >11 hours between two shifts) on insomnia, daytime sleepiness, and work-related fatigue compared to a shift schedule maintaining the usual number of quick returns. METHODS: A two-armed cluster randomized controlled trial including 66 units was conducted at a university hospital in Norway. Units with healthcare workers on rotating shift schedules were randomly assigned to a shift schedule with abated quick returns (intervention) or to continue with a schedule including quick returns as usual (control) for six months. Questionnaires assessed symptoms of insomnia (Bergen Insomnia Scale), daytime sleepiness (Epworth Sleepiness Scale), and work-related fatigue (Revised Swedish Occupational Fatigue Inventory) at baseline and towards the end of the intervention. Data was analyzed using multilevel linear mixed-effects models, and Cohen's d was used to calculate the effect size between groups. RESULTS: Overall, 1314 healthcare workers (85.2% female) completed the baseline questionnaire (response rate 49.1%), and 552 completed the follow-up questionnaire. The intervention reduced quick returns from an average of 13.2 (SD=8.7) to 6.7 (SD=6.0), while the control group's average remained relatively unchanged from 13.2 (SD=8.7) to 12.0 (SD=9.3). Results showed a small improvement in symptoms of insomnia (BIS; d=-0.13, p=0.022) and daytime sleepiness (ESS; d=-0.14, p=0.013) in favor of the intervention. No effects were observed on work-related fatigue. CONCLUSIONS: Reducing the number of quick returns resulted in improvements in insomnia and daytime sleepiness. The findings highlight the importance of sufficient rest time in the work schedule of healthcare workers.

Simulated quick returns in a laboratory context and effects on sleep and pre-sleep arousal between shifts: a crossover controlled trial.

This trial presents a laboratory model investigating the effect of quick returns (QRs, <11 h time off between shifts) on sleep and pre-sleep arousal. Using a crossover design, 63 participants worked a simulated QR condition (8 h time off between consecutive evening- and day shifts) and a day-day (DD) condition (16 h time off between consecutive day shifts). Participants slept at home and sleep was measured using a sleep diary and sleep radar. Compared to the DD condition, the QR condition reduced subjective and objective total sleep time by approximately one hour (both p < .001), reduced time in light- (p < .001), deep- (p = .004), rapid eye movement (REM, p < .001), percentage of REM sleep (p = .023), and subjective sleep quality (p < .001). Remaining sleep parameters and subjective pre-sleep arousal showed no differences between conditions. Results corroborate previous field studies, validating the QR model and indicating causal effects of short rest between shifts on common sleep parameters and sleep architecture.

This trial proposes a laboratory model to investigate the consequences of quick returns (QRs, <11h time off between shifts) on subjective/objective sleep and pre-sleep arousal. QRs reduced total sleep time, light-, deep-, REM sleep, whereas pre-sleep arousal was unaffected. Results emphasise the importance of ensuring sufficient rest time between shifts.Abbreviation: QR: Quick return; DD: Day-day; NREM: Non-rapid eye movement; REM: Rapid eye movement; PSG: Polysomnography; TIB: Time in bed; SOL: Sleep onset latency; WASO: Wake after sleep onset; TST: Total sleep time; EMA: Early morning awakening; PSAS: Pre-Sleep Arousal Scale; MEQ: Morning-Evening Questionnaire; LMM: Linear mixed model; EMM: Estimated marginal mean; SD: Standard deviation; SE: Standard error; d: Cohens' d; h: hours; m: minutes.

Changes in work schedule affect headache frequency among Norwegian nurses: a 3-year-follow-up study.

OBJECTIVES: To explore whether changes in work schedule, number of night shifts and number of quick returns were related to changes in headache frequencies. METHODS: A longitudinal study with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule (day only, shift work without nights and shift work with nights), number of night shifts, number of quick returns (less than 11 hours in-between shifts) and validated headache diagnoses among 1104 Norwegian nurses. Associations were explored by adjusted multivariate regression analyses. RESULTS: The median age at baseline was 37 years (IQR 31-43) and 90.5% were women. In the adjusted logistic regression analysis of changed work schedule between baseline and follow-up, changing from night work was associated with increased odds for reversion from headache >1 days/month to no headache at all last year (OR 2.77 (1.29; 5.95)). Changes towards less night shifts (>10) or quick returns (>10) during the last year were associated with increased odds of reversion of headache to no headache (OR 2.23 (1.20; 4.17) and OR 1.90 (1.04; 3.49)). Only decrease in number of night shifts (>10) during the last year reduced risk of onset of any new headache between baseline and follow-up (OR of 0.39 (0.18; 0.84)). CONCLUSION: Changing from night work and reducing the number of night shifts and quick returns were associated with less headache in this 3-year-follow-up of Norwegian nurses. This adds to the growing body of evidence that night work may have direct negative health consequences.

The associations between different types of infections and circadian preference and shift work.

Disturbed sleep and circadian disruption are reported to increase the risk of infections. People with an evening circadian preference and night workers typically report insufficient sleep, and the aims of the present study were to investigate possible associations between various types of infections and circadian preference and shift work status. Data were collected from an online cross-sectional survey of 1023 participants recruited from the Norwegian practice-based research network in general practice - PraksisNett. The participants completed questions about circadian preference (morning type, intermediate type, evening type), work schedule (day work, shift work without nights, shift work with night shifts), and whether they had experienced infections during the last three months (common cold, throat infection, ear infection, sinusitis, pneumonia/bronchitis, COVID-19, influenza-like illness, skin infection, gastrointestinal infection, urinary infection, venereal disease, eye infection). Data were analyzed with chi-square tests and logistic regression analyses with adjustment for relevant confounders (gender, age, marital status, country of birth, children living at home, and educational level). Results showed that evening types more often reported venereal disease compared to morning types (OR = 4.01, confidence interval (CI) = 1.08-14.84). None of the other infections were significantly associated with circadian preference. Shift work including nights was associated with higher odds of influenza-like illness (OR = 1.97, CI = 1.10-3.55), but none of the other infections. In conclusion, neither circadian preference nor shift work seemed to be strongly associated with risk of infections, except for venereal disease (more common in evening types) and influenza-like illness (more common in night workers). Longitudinal studies are needed for causal inferences.

The long-term effect of work schedule, shift work disorder, insomnia and restless legs syndrome on headache among nurses: A prospective longitudinal cohort study.

BACKGROUND: The preset study aimed to explore whether work schedules and sleep disorders predict the onset of headache. METHODS: A longitudinal study was conducted with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule, number of night shifts, number of quick returns, insomnia, shift work disorder (SWD), restless legs syndrome (RLS) and validated headache diagnoses among 1560 Norwegian nurses. Associations were explored by multivariate regression analyses. RESULTS: Work related factors at baseline did not predict onset of headache three years later. In the adjusted logistic regressions, insomnia at baseline predicted increased risk of new onset of migraine (odds ratio (OR) = 1.58; 95% confidence interval (CI) = 1.08-2.33), chronic headache (OR = 2.02; 95% CI = 1.04-4.66) and medication-overuse headache (OR = 3.79; 95% CI = 1.26-11.42) at follow-up. SWD at baseline predicted new onset of migraine (OR = 1.64; 95% CI = 1.07-2.50) and RLS at baseline predicted new onset of headache ≥1 day per month (OR = 1.55; 95% CI = 1.01-2.36) and migraine (OR = 1.55; 95% CI = 1.03-2.32) at follow-up. No factors predicted tension-type headache. CONCLUSIONS: Overall, work related factors did not predict the onset of headache three years later, whereas insomnia, SWD and RLS at baseline all increased the risk of future headaches.

The association between different sleep health dimensions and sex, age, education, circadian preference, and chronic insomnia: a representative population-based study.

Objectives: The aims were to explore multidimensional sleep health and the different dimensions of sleep health in the adult Norwegian population in relation to sex, age, education, circadian preference, and chronic insomnia. Methods: A representative sample of 1028 Norwegians, aged 18 + years completed a cross-sectional web-based survey. Sleep health was measured with the multidimensional RU_SATED scale, which assesses the dimensions of regularity, satisfaction, alertness, timing, efficiency, and duration. Insomnia was assessed with the Bergen Insomnia Scale. Data were analyzed with chi-square tests, t-tests, one-way ANOVAs, and regression analyses, as appropriate. Response rate was 33.5%. Results: Sleep health was better in males, with increasing age, and with higher educational level, and was poorer in participants with evening preference and chronic insomnia, compared to their respective counterparts. When investigating the different sleep health dimensions, males scored better than females on satisfaction (adjusted odds ratio [aOR] = 0.69, 95% CI = 0.51 to 0.93), timing (aOR = 0.66, 95% CI = 0.49 to 0.88), and efficiency (aOR = 0.68, 95% CI = 0.52 to 0.89). Older age was associated with better scores on regularity and satisfaction, whereas young age was associated with better scores on alertness and duration. High educational level was associated with better scores on alertness, timing, and duration. Evening types scored worse than morning types on regularity (aOR = 0.27, 95% CI = 0.18 to 0.41), satisfaction (aOR = 0.37, 95% CI = 0.26 to 0.53), and timing (aOR = 0.36, 95% CI = 0.26 to 0.51). Participants with chronic insomnia scored worse than participants without insomnia on all six sleep health dimensions. Conclusions: Sleep health differed significantly in relation to sex, age, education, circadian preference, and chronic insomnia. However, specific group differences were not equally evident in all sleep health dimensions.

Self-reported short and long sleep duration, sleep debt and insomnia are associated with several types of infections: Results from the Norwegian practice-based research network in general practice - PraksisNett.

Objective: The objective was to assess the association between self-reported infections and sleep duration, sleep debt, chronic insomnia, and insomnia severity. Methods: In total, 1023 participants were recruited from the Norwegian practice-based research network in general practice to a cross-sectional online survey with validated questions about sleep habits and insomnia symptoms (Bergen Insomnia Scale (BIS) and Insomnia Severity Index (ISI)), and whether they had experienced various infections during the last three months. Data were analyzed with chi-square tests and logistic regressions with adjustment for relevant confounders. Results: Self-reported short sleep duration (<6 h) was significantly associated with increased odds of throat infection (OR = 1.60), ear infection (OR = 2.92), influenzalike illness (OR = 1.81) and gastrointestinal infection (OR = 1.91) whereas long sleep duration (>9 h) was associated with increased odds of throat (OR = 3.33) and ear infections (OR = 5.82), compared to sleep duration of 6-9 h, respectively. Sleep debt of >2 h was associated with increased odds of the common cold (OR = 1.67), throat infection (OR = 2.58), ear infection (OR = 2.84), sinusitis (OR = 2.15), pneumonia/bronchitis (OR = 3.97), influenzalike illness (OR = 2.66), skin infection (OR = 2.15), and gastrointestinal infection (OR = 2.80), compared to no sleep debt. Insomnia (based on BIS and ISI) was associated with throat infection (OR = 2.06, 2.55), ear infection (OR = 2.43, 2.45), sinusitis (OR = 1.82, 1.80), pneumonia/bronchitis (OR = 2.23, 3.59), influenzalike illness (OR = 1.77, 1.90), skin infection (OR = 1.64, 2.06), gastrointestinal infection (OR = 1.94, 3.23), and eye infection (OR = 1.99, 2.95). Conclusions: These novel findings support the notion that people who have insufficient sleep or sleep problems are at increased risk of infections.

Associations between excessive fatigue and pain, sleep, mental-health and work factors in Norwegian nurses.

AIM: To investigate whether pain, sleep duration, insomnia, sleepiness, work-related factors, anxiety, and depression associate with excessive fatigue in nurses. BACKGROUND: Fatigue among nurses is a problem in the context of ongoing nursing shortages. While myriad factors are associated with fatigue not all relationships are understood. Prior studies have not examined excessive fatigue in the context of pain, sleep, mental health, and work factors in a working population to determine if associations between excessive fatigue and each of these factors remain when adjusting for each other. METHODS: A cross-sectional questionnaire study among 1,335 Norwegian nurses. The questionnaire included measures for fatigue (Chalder Fatigue Questionnaire, score ≥4 categorized as excessive fatigue), pain, sleep duration, insomnia (Bergen Insomnia Scale), daytime sleepiness (Epworth Sleepiness Scale), anxiety and depression (Hospital Anxiety and Depression Scale), and work-related factors. Associations between the exposure variables and excessive fatigue were analyzed using chi-square tests and logistic regression analyses. RESULTS: In the fully adjusted model, significant associations were found between excessive fatigue and pain severity scores for arms/wrists/hands (adjusted OR (aOR) = 1.09, CI = 1.02-1.17), hips/legs/knees/feet (aOR = 1.11, CI = 1.05-1.18), and headaches/migraines (aOR = 1.16, CI = 1.07-1.27), sleep duration of <6 hours (aOR = 2.02, CI = 1.08-3.77), and total symptom scores for insomnia (aOR = 1.05, CI = 1.03-1.08), sleepiness (aOR = 1.11, CI = 1.06-1.17), anxiety (aOR = 1.09, CI = 1.03-1.16), and depression (aOR = 1.24, CI = 1.16-1.33). The musculoskeletal complaint-severity index score (aOR = 1.27, CI = 1.13-1.42) was associated with excessive fatigue in a separate model adjusted for all variables and demographics. Excessive fatigue was also associated with shift work disorder (OR = 2.25, CI = 1.76-2.89) in a model adjusted for demographics. We found no associations with shift work, number of night shifts and number of quick returns (<11 hours between shifts) in the fully adjusted model. CONCLUSION: Excessive fatigue was associated with pain, sleep- and mental health-factors in a fully adjusted model.

Habitual Sleep Patterns and Chronic Sleep Problems in Relation to Sex, Age, and Circadian Preference in a Population-Based Sample of Norwegian Adults.

Sleep patterns and problems vary in relation to internal (e.g., sex, age, circadian preference) and external (e.g., social structures) factors. The main aim of the present study was to describe habitual sleep patterns and chronic sleep problems in a population-based sample of Norwegian adults. During spring 2022, a sample of 1028 adults completed an online survey on sleep habits and problems. Response rate was 33.5%. The survey included the Munich ChronoType Questionnaire and items on circadian preference and chronic sleep problems. Mean workday sleep duration was 7:19 h (±199 min), and shorter in males (p = 0.035) and evening persons (p = 0.003). Short workday sleep duration (<6 h) was reported by 3.1% and was associated with evening preference (p = 0.001). Mean social jetlag was 0:51 h (±75 min), and longer in males (p = 0.036), younger adults (p < 0.001) and evening persons (p < 0.001). Long social jetlag (≥2 h) was reported by 11.2% and associated with younger age (p < 0.001) and evening preference (p < 0.001). Chronic sleep problems (≥3 months) were reported by 44.1%, and associated with female sex (p < 0.001) and evening preference (p = 0.002). Results underscore the importance of considering evening circadian preference as a risk factor for short workday sleep duration, long social jetlag and self-reported chronic sleep problems.

Do people use methods or tricks to fall asleep? A comparison between people with and without chronic insomnia.

The present study estimated the frequency of using methods or tricks to fall asleep in the general Norwegian population. Further, people with chronic insomnia were compared with people without chronic insomnia. A representative sample of 1028 participants aged 18 years or older completed a web-based survey. The response rate was 33.5%. Insomnia symptoms were assessed with the validated Bergen Insomnia Scale, and chronic insomnia based on ICSD-3/DSM-5 criteria. Data were analysed with chi-square tests and logistic regression with adjustment for sex, age, education, and circadian preference. The results showed that 34.3% reported using a method or a trick to fall asleep, with relaxation exercises/breathing exercises being the most common. More females (39.5%) compared with males (29.1%) reported the use of a method/trick to fall asleep with an adjusted odds ratio (aOR) of 1.44. Chronic insomnia was reported by 24.9%, and clearly associated with higher use of such methods/tricks (53.7%; aOR = 3.49). Among the participants without chronic insomnia, 28.1% reported using methods/tricks to fall asleep. In conclusion, most people do not use methods or tricks to fall asleep, but chronic insomnia was associated with a higher frequency of such use. Still, since methods/tricks were also used by some participants without chronic insomnia, this may suggest that, for some people, this strategy may be effective or at least does not seem to disrupt the sleep onset process.

Changes in the Work Schedule of Nurses Related to the COVID-19 Pandemic and Its Relationship with Sleep and Turnover Intention.

Background: This study aimed to investigate whether different types of changes in the work schedule of nurses working rotating shifts during the COVID-19 pandemic were associated with sleep duration, sleep quality, and turnover intention. Methods: Cross-sectional questionnaire data from 694 nurses participating in the SUrvey of Shift work, Sleep and Health (SUSSH) were collected between the first and the second wave of the COVID-19 pandemic in Norway. A total of 89.9% were female, and mean age was 44.6 years (SD = 8.6 years). Changes in the shift work schedule related to the pandemic comprised reports of more long workdays (>8 h), less days off between work periods, more night shifts, more quick returns (i.e., 11 h or less between two consecutive shifts), more day shifts, and more evening shifts compared to no change in the respective shift characteristics. Change in sleep duration, sleep quality, and turnover intention as well as demographics were also assessed. Logistic regression analyses were performed to investigate whether changes in the specific work schedules were associated with sleep duration, sleep quality, and turnover intention, controlling for sex, age, cohabitation, children living in household, percentage of full time equivalent and other changes in the work schedule. Results: A total of 17% reported experiencing one or more changes in their work schedule during the pandemic. Experiencing any change in the work schedule predicted worse sleep quality (OR = 2.68, p < 0.001), reduced sleep duration (OR = 4.56, p < 0.001), and higher turnover intention (OR = 1.96, p = 0.006) compared to experiencing no change in work schedule. Among the specific changes in work schedules, experiencing an increase in quick returns had the highest odds ratio for worse sleep quality (OR = 10.34, p = 0.007) and higher turnover intention (OR = 8.49, p = 0.014) compared to those who reported no change in quick returns. Nurses experiencing an increase in long workdays were more likely to report higher turnover intention (OR = 4.37, p = 0.003) compared to those experiencing no change in long workdays. Conclusions: Change in work schedule related to the pandemic was associated with worse sleep quality, reduced sleep duration, and higher turnover intention. Increase in quick returns emerged as especially problematic in terms of sleep quality and turnover intention, along with long workdays, which were associated with higher turnover intention.

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.

A shift to something better? A longitudinal study of work schedule and prescribed sleep medication use in nurses.

OBJECTIVES: To explore whether a change in work schedule was associated with a change in the probability of prescribed sleep medication use. METHODS: A longitudinal study with annual questionnaire data (2008/2009-2021, except 2019) on work schedule (day work only, shift work without nights and shift work with nights) and prescribed sleep medication use from 2028 Norwegian nurses (mean age 31.7 years, 90.5% women at baseline) who participated in the ongoing Survey of Shift work, Sleep and Health (SUSSH). Associations were estimated using a random effects model, and a fixed effects regression model in which nurses were included as their own control to account for potential unobserved confounding. RESULTS: In both models, day work was associated with a more than 50% lower probability of sleep medication use compared with shift work with nights (adjusted OR (aOR) 0.50, 95% CI 0.27 to 0.93 in the random effects model, and an aOR 0.32, 95% CI 0.14 to 0.70 in the fixed effects regression model). Shift work without nights was associated with a non-statistically significant reduction in sleep medication use within nurses in the fixed effects regression model when compared with shift work with nights (aOR 0.66, 95% CI 0.37 to 1.20). CONCLUSIONS: Day work was associated with a significant reduced probability of prescribed sleep medication use compared with shift work with nights. This indicates that quitting night work will improve sleep and thereby reduce hypnotic use.

The association between shift work disorder and turnover intention among nurses.

BACKGROUND: Shift work disorder (SWD) is highly prevalent among shift-working nurses and has multiple negative health-related effects. There is a dearth of insight into career-related decisions made by nurses suffering from SWD, for instance in terms of their intention to quit work (turnover intention). In this study, we aimed to investigate the association between SWD and turnover intention among nurses, and the individual and work-related correlates of turnover intention. METHOD: Data were derived from the ongoing longitudinal cohort study "SUrvey of Shift work, Sleep and Health (SUSSH)" among Norwegian nurses. An annual survey was initiated in 2008/2009 (N = 2965). The present study used data collected in year 2015 (wave 7) and 2016 (wave 8). Nurses were included if: 1) they were working as nurses in both 2015 and 2016, and 2) had completed a three-item scale adapted from the Michigan Organizational Assessment Questionnaire assessing turnover intention (in wave 8), and 3) did not only work day-shifts. SWD was measured in wave 7 with three questions based on the minimal criteria from the third edition of the International Classification of Sleep Disorders. Job demands, decision latitude, and social support at the workplace were measured with subscales of the Swedish Demand-Control-Support Questionnaire. RESULTS: Eight Hundred eighty-nine nurses were included. The results from the hierarchical linear regression showed that SWD predicted turnover intention one year later, i.e. from 2015 to 2016 (F1,835 = 6.00, p < 0.05; ß = 0.084, p = 0.015). The findings remained significant when controlling for age, sex, organizational tenure, number of nights worked, shift work schedule and workplace social support, job demands and decision latitude. CONCLUSION: This study showed that SWD is associated with turnover intention, even when controlling for individual and work-related variables.

Health-promoting work schedules: protocol for a large-scale cluster randomised controlled trial on the effects of a work schedule without quick returns on sickness absence among healthcare workers.

INTRODUCTION: In shift work, quick returns refer to transitions between two shifts with less than 11 hours available rest time. Twenty-three per cent of employees in European countries reported having quick returns. Quick returns are related to short sleep duration, fatigue, sleepiness, work-related accidents and sickness absence. The present study is the first randomised controlled trial (RCT) to investigate the effect of a work schedule without quick returns for 6 months, compared with a work schedule that maintains quick returns during the same time frame. METHODS AND ANALYSIS: A parallel-group cluster RCT in a target sample of more than 4000 healthcare workers at Haukeland University Hospital in Norway will be conducted. More than 70 hospital units will be assessed for eligibility and randomised to a work schedule without quick returns for 6 months or continue with a schedule that maintains quick returns. The primary outcome is objective records of sickness absence; secondary outcomes are questionnaire data (n≈4000 invited) on sleep and functioning, physical and psychological health, work-related accidents and turnover intention. For a subsample, sleep diaries and objective sleep registrations with radar technology (n≈ 50) will be collected. ETHICS AND DISSEMINATION: The study protocol was approved by the Regional Committee for Medical and Health Research Ethics in Western Norway (2020/200386). Findings from the trial will be disseminated in peer-reviewed journals and presented at national and international conferences. Exploratory analyses of potential mediators and moderators will be reported. User-friendly outputs will be disseminated to relevant stakeholders, unions and other relevant societal groups. TRIAL REGISTRATION NUMBER: NCT04693182.

Sleep and Sleepiness Measured by Diaries and Actigraphy among Norwegian and Austrian Helicopter Emergency Medical Service (HEMS) Pilots.

The study examined sleep and sleepiness among shift working Helicopter Emergency Medical Service pilots from Norway (Norwegian Air Ambulance; NAA) and Austria (Christophorus Flugrettungverein; CFV). Both pilot groups (N = 47) worked seven consecutive 24 h shifts. Sleep was assessed by diaries and actigraphy while sleepiness was assessed by the Karolinska Sleepiness Scale, all administered throughout the workweek. The results indicated that all pilots had later bedtime (p < 0.05) and wake-up time (p < 0.01) as they approached the workweek end, but no change during the workweek was evident regarding wake after sleep onset, time in bed, total sleep time, or sleep efficiency. The NAA pilots had later bedtime (p < 0.001) and wake-up time (p < 0.001), spent more time awake after sleep onset (p < 0.001), more time in bed (p < 0.001), slept longer (p < 0.01), and had lower sleep efficiency (p < 0.001) compared with the CFV pilots. The sleepiness levels of all pilots were slightly elevated on the first workday but lower on the following workdays (day 2p < 0.001, day 3p < 0.05). For both pilot groups, no major change in sleep or sleepiness parameters throughout the workweek was detected. The NAA pilots reported somewhat more disturbed sleep but obtained more sleep compared with the CFV pilots.

Bright light exposure during simulated night work improves cognitive flexibility.

Night work leads to sleepiness and reduced vigilant attention during work hours, and bright light interventions may reduce such effects. It is also known that total sleep deprivation impairs cognitive flexibility as measured by reversal learning tasks. Whether night work impairs reversal learning task performance or if bright light can mitigate reversal learning deficits during night work is unclear. In this counterbalanced crossover study (ClinicaTrials.gov Identifier NCT03203538), young healthy individuals completed a reversal learning task twice during each of three consecutive simulated night shifts (23:00-07:00 h). The night shifts were performed in a laboratory under a full-spectrum (4000 K) bright light (~900 lx) and a standard light (~90 lx) condition. Reversal learning task performance was reduced towards the end of the night shifts (04:50 h), compared to the first part of the night shifts (00:20 h) in both light conditions. However, with bright light, the reversal learning task performance improved towards the end of the night shifts, compared to standard light. The study shows that bright light may mitigate performance deficits on a reversal learning task during night work and implies that bright light interventions during night work may be beneficial not only for vigilant attention but also for cognitive flexibility.

Sleep medication and melatonin use among Norwegian nurses - A cross-sectional study.

AIM: To estimate the prevalence of sleep medication and melatonin use among nurses and to assess if factors related to work, sleep or mental health, were associated with such use. DESIGN: A cross-sectional study. METHODS: A questionnaire survey including 2,798 Norwegian nurses. Associations were estimated using a modified Poisson regression model. RESULTS: In total, 7.5%, 4.6% and 2.0% of the nurses included in the present study reported prescribed sleep medication, over-the-counter sleep medication or melatonin use in the last year, respectively. Short sleep duration, sleep problems and psychological conditions were strongly associated with both prescribed and over-the-counter sleep medication use. Nurses who worked more than 60 night shifts in the last year were at increased risk of sleep medication use.

Restless legs syndrome - a study from general practice. / Rastløse bein ­ en studie fra allmennpraksis.

BACKGROUND: The prevalence of restless legs syndrome (RLS) among adults in the general population is around 5-10 %. Few studies have been conducted on the prevalence among patients who consult their general practitioner. There are also few studies on associations between RLS and other common complaints such as irritable bowel syndrome (IBS), chronic fatigue (CF) and chronic muscle and back pain (CMBP). MATERIAL AND METHOD: The study was conducted as a questionnaire survey at medical offices in Southern and Western Norway in the autumn of 2017 and spring of 2018, when patients waiting to see their general practitioner (GP) were invited to participate. A total of 2 634 people took part (62.2 % women, average age 49.6 years). The response rate was 86.8 %. Restless legs syndrome (RLS) was defined on the basis of international criteria. Associations between RLS and IBS, CF and CMBP were analysed by means of chi-squared tests and logistic regression. RESULTS AND INTERPRETATION: The proportion of patients with RLS was 14.3 %. Of the patients with RLS, 44.8 % reported that their symptoms were moderately to very distressing, and 85.8 % that they did not use medication for it. The proportion of patients with RLS was significantly higher among patients with IBS (21.8 % versus 13.6 %, p = 0.009), CF (18.2 % versus 13.1 %, p = 0.003) and CMBP (23.2 % versus 12.2 %, p < 0.0005). GPs should be aware that many patients have RLS and that the condition is associated with other common complaints.

Stability and Change of the Personality Traits Languidity and Flexibility in a Sample of Nurses: A 7-8 Years Follow-Up Study.

The traits languidity (tendency to become tired/sleepy upon losing sleep) and flexibility (ability to sleep and work at odd times) have been implicated in shift work tolerance. However, there is a dearth of knowledge about their temporal stability. The aim of the present study was to explore these traits during a long follow-up (FU) period and identify factors related to potential changes in trait scores over time. In all, 1,652 nurses completed the Circadian Type Inventory-revised (CTI-r), which measures languidity and flexibility, at both 2008/2009 (baseline, BL) and again in 2016 (FU). The latent scores of these two constructs at BL, in addition to age, sex, childcare responsibility, marital status, night work status, and insomnia status, were regressed on the corresponding latent scores at follow-up using a structural equation modeling (SEM) approach. Stability was found for both languidity (rho = 0.59) and flexibility (rho = 0.58). Both composite scores declined significantly from baseline (20.62 and 12.48) to follow-up (19.96 and 11.77). Languidity at baseline was positively associated with languidity at follow-up (ß = 0.89, p < 0.009). Undertaking childcare responsibility between baseline and follow-up was inversely related to languidity at follow-up (ß = -0.09, p < 0.05). Starting night work was positively related to languidity at follow-up (ß = 0.06, p < 0.05). Developing insomnia between baseline and follow-up (ß = 0.15, p < 0.05) was positively, whereas remitting from insomnia during the same period was negatively (ß = -0.11, p < 0.01) associated with languidity at follow-up. Flexibility at baseline was positively associated with flexibility at follow-up (ß = 0.64, p < 0.05). Having childcare responsibility at baseline, but not at follow-up was inversely related to flexibility at follow-up (ß = -0.05 p < 0.05). Becoming cohabitant with a partner between baseline and follow-up (ß = -0.07, p < 0.05) was negatively associated with flexibility at follow-up. Starting night work between baseline and follow-up (ß = 0.17, p < 0.01) and reporting night work at both baseline and follow-up (ß = 0.18, p < 0.01) were both positively associated with flexibility at follow-up, whereas stopping working nights was negatively (ß = -0.09, p < 0.05), associated with flexibility at follow-up. The personality traits languidity and flexibility show fairly high stability, albeit the mean scores were significantly reduced during the 7-8 years follow-up period. The results suggest that these personality traits are partly modifiable.