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Age and sleep both affect emotional functioning. Since sleep patterns change over the lifespan, we investigated the effects of short sleep and age on empathic responses. In a randomized cross-over experimental design, healthy young and older volunteers (n = 47 aged 20–30 years and n = 39 aged 65–75 years) underwent functional magnetic resonance imaging (fMRI) after normal sleep or night sleep restricted to 3 hours. During fMRI, participants viewed pictures of needles pricking a hand (pain) or Q-tips touching a hand (control), a well-established paradigm to investigate empathy for pain. There was no main effect of sleep restriction on empathy. However, age and sleep interacted so that sleep restriction caused increased unpleasantness in older but not in young participants. Irrespective of sleep condition, older participants showed increased activity in angular gyrus, superior temporal sulcus and temporo-parietal junction compared to young. Speculatively, this could indicate that the older individuals adopted a more cognitive approach in response to others’ pain. Our findings suggest that caution in generalizability across age groups is needed in further studies of sleep on social cognition and emotion., This work was funded by Stockholm Stress Center, Riksbankens Jubileumsfond, Karolinska Institutet, Stockholm County Council, Isabella and Henrik Berg and the Heumanska stiftelsen/Hjärnfonden, Fredrik and Ingrid Thuring’s Foundation.

Introduction: Sleep deprivation has been reported to affect intrinsic brain connectivity, notably in the default mode network, but studies to date have shown inconsistent effects and have largely included young participants. We therefore aimed to investigate effects of partial sleep deprivation on intrinsic brain connectivity in young and older participants. Methods: Participants aged 20-30 (n = 30) and 65-75 (n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Participants were monitored with eye-tracking to ensure they did not fall asleep during scanning. Results: Sleep deprivation caused increased global signal variability, defined as log-transformed standard deviation of average gray matter signal (0.16 [0.07, 0.24], p = 0.0004). In contrast to previous studies, sleep deprivation did not cause major changes in investigated resting state networks, nor did it cause changes in regional homogeneity. Younger participants had higher functional connectivity in most examined resting state networks, as well as higher regional homogeneity in brain areas including anterior and posterior cingulate cortex. Conclusions: We show for the first time that partial sleep deprivation caused increased global signal variability. This outcome should be examined as a potential biomarker for sleepiness using independent data. Unlike a few earlier studies, we did not find less default mode connectivity in the sleep deprived state, possibly because of stricter monitoring of participants' wakefulness.

Introduction: Mind wandering, the drift of attention from the current task at hand to self-generated thought is commonly associated with poorer performance, and could be a potential pathway through which sleep deprivation affects performance. Little is known about this, however. Therefore, the aim of the present study was to address the effect of sleep deprivation on mind wandering and performance in a sustained attention task. In addition, we studied age as moderating factor, since older individuals are generally less prone to mind wandering. Materials and methods: Healthy young (18-30years) and older (60-72years) subjects participated in either a normal night sleep (NSD) or a total sleep deprivation (SD) condition, i.e. 4 conditions: NSD (n=31), SD (n=30), NSDold (n = 24), SDold (n= 24). Performance was measured using the Sustained Attention to Response Task, during which 10 thought probes were included that prompted the subjects to answer a question on what they were you just thinking about, using predefined answer alternatives. Mind wandering was quantified as occurrence of task-unrelated thoughts. Results: Applying a 2 (age) X 2 (sleep deprivation) ANOVA, significant main effects for sleep deprivation and age were observed for omissions, indicating worse performance after sleep deprivation and in young participants (p's < .05). These main effects were dominated by an age*sleep deprivation interaction (p = .04), which was due to sleep deprivation causing significantly more omission errors in young subjects (Mean ±SEM; NSD: 2.3 ±0.9; SD: 13.1 ±4.1) but not in older subjects (NSDold: 1.9 ±0.4; SDold: 2.8 ±0.9). Likewise, main and interaction effects for age and sleep deprivation were significant for task-unrelated thoughts (p's < 0.01). Task unrelated thoughts were significantly more frequent after sleep loss in young (NSD: 1.5 ±0.2; SD: 4.3 ±0.6), but not older subjects (NSDold: 0.3 ±0.2; SDold: 0.5 ±0.2) (interaction age*sleep deprivation p < .01). Youn, This study was funded by the Bank of Sweden Tercentenary Foundation.

Introduction: Even though the occurrence of sleep problems increases with age, few studies have focused on the cognitive effects of acute sleep deprivation in elderly. Most previous research indicate that, compared to young, older adults show less impairment in e.g. attention after sleep deprivation. However, little is known of whether the same pattern holds for higher cognitive functions. In addition, while old age is usually related to a general decrease in working memory abilities, performance on working memory tasks may differ depending on the emotional valence of the stimuli, where positive stimuli seem to be beneficial for working memory performance in older adults. The aim of the present study was to investigate the effect of sleep deprivation on emotional working memory in older adults using two levels of working memory load. Materials and methods: A healthy sample of 48 old adults (MAge=66.69 years, SDAge=3.44 years) was randomized into a total sleep deprivation group (TSD; n=24) or a sleep control group (SC; n=24). They performed a working memory task (n-back) containing positive, negative and neutral pictures in a low (1-back) and a high (3-back) working memory load condition. Performance was measured as Accuracy (d'), Omissions and Reaction Time (RT). Results: For the d' and Omissions we performed two separate 2x2x3 (sleep, working memory load, valence) repeated measures analyses of variance (rmANOVA). For the RTs, we applied a mixed-effects model. For both d' and RT we found no effect of sleep deprivation (Ps > .05). For valence, we found main effects on both d' (F1,46 = 5.56, P=.005) and RT (F1,95.7 = 4.84, P=.01). d' did not differ for positive and neutral pictures, but was in both cases significantly better than for negative pictures. RTs were significantly faster for positive pictures. However, a working memory load∗valence interaction (F1,95.7 = 4.50, P=.01) further revealed an effect of valence in the low, but not in the high load condition. In, This study was funded by the Bank of Sweden Tercentenary Foundation.

Purpose: This systematic meta-review uses the job demands-resources (JD-R) model as a starting point for reporting on how various psychosocial factors at work relate to different outcomes. Specifically, the review investigated how job demands and resources associate with job attitudes and behaviours and whether these linkages vary between genders and occupations. Design/Methodology: This meta-review includes meta-analyses and systematic literature reviews published during the past 10 years. The secondary studies were retrieved from combined searches in different international databases. Search terms were chosen to target a range of psychosocial factors and to retrieve published journal articles, and systematic reports linking such factors to job attitudes and behaviours. Results: In total, 14 job demands and 7 job resources were identified. These were linked to outcomes resulting in 147 associations being identified. Overall, the findings summarize what is known from previous systematic reviews, namely that job demands are associated with poorer attitudes and behaviours while resources typically relate to attitudes and behaviours that are beneficial both for employers and individual employees. However, for gender and occupation, considerably less is known. Importantly, however, reports of gender specific associations suggest that, overall, linkages between psychosocial factors and job attitudes and behaviours hold for both women and men. Limitations: The restriction to the past 10 years. Research/Practical Implications: The meta-review adds to understanding consequences of psychosocial factors at work and points up future research needs. Originality/Value: The broad approach using a meta-review allows for integrating research on several outcomes., This contribution draws on a report commissioned by the Swedish Work Environment Authority. This research was carried out within Stockholm Stress Center, a center for excellence supported by FORTE.

This report includes a research overview commissioned by the Swedish Work Environment Authority with the aim of detailing relationships between organizational and psychosocial factors at work, and various work-related and health-related outcomes among working women and men. A second aim involved reporting on the prevalence of the different work environment factors among women and men. To fulfil the first aim, systematic research reviews, including meta-analyses and literature reviews, were retrieved from combined searches in different international and national databases. Search terms were chosen to target the broad array of organizational and psychosocial factors, and to retrieve published journal articles and systematic reports of Swedish government agencies linking such factors to various outcomes. The time period was restricted to the past ten years.

Purpose: This systematic meta-review uses the job demands-resources (JD-R) model to investigate the associations between various psychosocial factors at work and a range of health-related outcomes. Specifically, this study investigated how job demands and resources are linked to health-related outcomes such as depressive symptoms, cardiovascular disease and musculoskeletal complaints and whether the linkages varied between genders and occupations. Design/Methodology: This meta-review focuses on meta-analyses and systematic literature reviews published during the past 10 years. These secondary studies were identified through combined searches in different international databases. Search terms were selected to identify a range of psychosocial factors and to retrieve published journal articles, and systematic reports linking such factors to health-related outcomes. Results: In total, 14 job demands and 7 job resources were identified. Lining these to outcomes resulted in the identification of 273 potential associations. Taken together, the findings show what is known from previous research, namely that job demands are related to poorer health. As expected resources typically relate to better health outcomes that are beneficial for organizations and individual employees. Separating findings for women and men suggest that the overall linkages between psychosocial factors and health-related outcomes hold for both women and men. However, less is know regarding occupational variations. Limitations: A meta-review restricts specificity and detail. Research/Practical Implications: Adds to the systematic knowledge of health-related consequences of psychosocial factors at work, for research as well as practice. Originality/Value: The use of a meta-approach that discusses issues relating to gender and occupation., This contribution draws on a report commissioned by the Swedish Work Environment Authority. This research was carried out within Stockholm Stress Center, a center for excellence supported by FORTE.

Human fatigue continues to threaten safe transport. There are claims that employers of operators should do more to mitigate the risks, and several regulators are promoting fatigue-risk management in the context of safety management systems (SMS). The current paper reviews fatigue-related risk and exposure factors and control measures for operators of land- and sea-based transport forms. Our review identifies 13 types of measures for the monitoring or control of fatigue risks: optimal staffing; optimal schedule design; optimisation of breaks/naps; monitoring of actual hours worked; optimisation of work content; monitoring and feedback of actual sleep; health screening and treatment; promotion of recovery from work; fitness-for-duty testing; monitoring of fatigue symptoms while operating; control of fatigue while operating; performance monitoring and assistance; and fatigue-proofing. We also identify two systemic measures needed to anchor risk mitigation in SMS: organisational learning and training/other. By structuring monitoring and control measures along Dawson and McCulloch's fatigue-risk trajectory, a framework is obtained that acts as a guide for fatigue-risk management by transport employers. To inform transport managers further, evaluations are needed of the effectiveness of individual control measures as well as whole fatigue-risk management interventions.

Objectives Prostate cancer is the most common cancer and the second leading cause of cancer-related deaths among men, but the contributing factors are unclear. One such may be night work because of the day/night alternation of work and the resulting disturbance of the circadian system. The purpose of the present study was to investigate the prospective relation between number of years with night work and prostate cancer in men. Design Cohort study comparing night and day working twins with respect to incident prostate cancer in 12 322 men. Setting Individuals in the Swedish Twin Registry. Participants 12 322 male twins. Outcome measures Prostate cancer diagnoses obtained from the Swedish Cancer Registry with a follow-up time of 12 years, with a total number of cases=454. Results Multiple Cox proportional hazard regression analysis, adjusted for a number of covariates, showed no association between ever night work and prostate cancer, nor for duration of night work and prostate cancer. Analysis of twin pairs discordant for prostate cancer (n=332) showed no significant association between night work and prostate cancer. Conclusions The results, together with previous studies, suggest that night work does not seem to constitute a risk factor for prostate cancer.

The Stockholm Sleepy Brain Study I is a functional brain imaging study of 48 younger (20-30 years) and 36 older (65-75 years) healthy participants, with magnetic resonance imaging after normal sleep and partial sleep deprivation in a crossover design. We performed experiments investigating emotional mimicry, empathy for pain, and cognitive reappraisal, as well as resting state functional magnetic resonance imaging (fMRI). We also acquired T1- and T2-weighted structural images and diffusion tensor images (DTI). On the night before imaging, participants were monitored with ambulatory polysomnography and were instructed to sleep either as usual or only three hours. Participants came to the scanner the following evening. Besides MRI scanning, participants underwent behavioral tests and contributed blood samples, which have been stored in a biobank and used for DNA analyses. Participants also completed a variety of self-report measures. The resulting multimodal dataset may be useful for hypothesis generation or independent validation of effects of sleep deprivation and aging, as well as investigation of cross-sectional associations between the different outcomes. V. 2 of this manuscript published 2017-10-12. Changes: new co-author (Claus Lamm), changed affiliations for Kristoffer Månsson, minor changes in the abstract, and revisions of the main text and figures.

BACKGROUND: Sickness presence (SP) is a complex phenomenon that has been shown to predict sickness absence, poor work performance, and suboptimal self-rated health. However, more research is needed to increase the understanding of how SP relates to occupational factors, demographic variables, and self-rated health. OBJECTIVE: The aims of this study were to investigate (1) the prevalence of SP among the Police employees in Sweden in 2007 and in 2010; (2) the association between demographics, seniority, occupational group (police officer vs civil servant), and self-reported health on the one hand and SP on the other hand for both years separately. METHODS: Survey data from Swedish Police employees from 2007 (n = 17,512) and 2010 (n = 18,415) were analyzed using logistic regression to assess odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The prevalence of SP was stable between the years, but the proportion who stated that they had not been ill at all decreased from 2007 to 2010 (28.0% vs. 23.6%), while the proportion stating always having stayed at home when ill did not differ; 45.0% in 2007 to 45.8% in 2010. The ORs of SP were higher among those with suboptimal self-rated health compared to those with optimal self-rated health (4.38 (95% CI 4.02- 4.78) and 4.31 (3.96- 4.70) in 2007 and 2010, respectively) and among police officers compared with civilians (1.26 (1.17-1.36) and 1.19 (1.10-1.28)), whereas no clear patterns were found for age, gender, and seniority. CONCLUSIONS: The prevalences of SP were about the same in 2007 and 2010 and were slightly lower compared to in previous studies. The strong association between SP and suboptimal self-rated health suggests that high levels of SP may be an early marker of future illness and sickness absence. In future studies of SP it is important to account for having been ill, that is, at risk of SP.

Objectives: Higher age is associated with poorer sleep and women report more sleep problems than men, despite indications of better physiological sleep. The purpose of the present study was to investigate whether a common daily life sleep problem, late night curtailed sleep, would have different effects depending on gender and age. Methods: 60 healthy individuals (equal groups of gender and age (20–30 and 65–75 years)) participated in an experiment with a full night’s sleep and one night with reduced sleep between 0400 h and 0700 h, in a balanced design. Sleep was recorded through standard polysomnography (PSG) at home. Results: The results showed the expected main effect of sleep loss. Older participants had a lower TST, N3%, sleep efficiency, but more N1%, longer N3 latency, and fewer awakenings. Women had more N3%, more REM%, more N3%, and shorter N3 latency compared with men. The curtailed late night sleep caused a stronger increase in N3%, and more pronounced reductions in REM%, a stronger reduction in N1%, and N3 latency in women than men. In the higher age group the N3% response in men was strongly attenuated compared to that of women. Conclusions: The results show that women, apart form getting more N3% and less N1% even in the normal sleep condition, have a stronger response to late night sleep, particularly in higher age groups., The Tercentenary Fund of Bank of Sweden.

Aims: Past research has often neglected the sub-dimensions of work time control (WTC). Moreover, differences in levels of WTC with respect to work and demographic characteristics have not yet been examined in a representative sample. We investigated these matters in a recent sample of the Swedish working population. Methods: The study was based on the 2014 data collection of the Swedish Longitudinal Occupational Survey of Health. We assessed the structure of the WTC measure using exploratory and confirmatory factor analysis. Differences in WTC by work and demographic characteristics were examined with independent sample t-tests, one-way ANOVAs and gender-stratified logistic regressions. Results: Best model fit was found for a two-factor structure that distinguished between control over daily hours and control over time off (root mean square error of approximation = 0.06; 95% CI 0.04 to 0.09; Comparative Fit Index (CFI) = 0.99). Women, shift and public-sector workers reported lower control in relation to both factors. Age showed small associations with WTC, while a stronger link was suggested for civil status and family situation. Night, roster and rotating shift work seemed to be the most influential factors on reporting low control over daily hours and time off. Conclusions: Our data confirm the two-dimensional structure underlying WTC, namely the components 'control over daily hours' and 'control over time off'. Women, public-sector and shift workers reported lower levels of control. Future research should examine the public health implications of WTC, in particular whether increased control over daily hours and time off can reduce health problems associated with difficult working-time arrangements.

We examined whether the beneficial impact of work time control (WTC) on sleep leads to lower accident risk, using data from a nationally representative survey conducted in Sweden. Logistic regressions examined WTC in 2010 and 2012 as predictors of accidents occurring in the subsequent 2 years (N = 4840 and 4337, respectively). Sleep disturbance and frequency of short sleeps in 2012 were examined as potential mediators of the associations between WTC in 2010 and subsequent accidents as reported in 2014 (N = 3636). All analyses adjusted for age, sex, education, occupational category, weekly work hours, shift work status, job control and perceived accident risk at work. In both waves, overall WTC was inversely associated with accidents (p = 0.048 and p = 0.038, respectively). Analyses of the sub-dimensions of WTC indicated that Control over Daily Hours (influence over start and finish times, and over length of shift) did not predict accidents in either wave, while Control over Time-off (CoT; influence over taking breaks, running private errands during work and taking paid leave) predicted fewer accidents in both waves (p = 0.013 and p = 0.010). Sleep disturbance in 2012 mediated associations between WTC/CoT in 2010 and accidents in 2014, although effects' sizes were small (effectWTC = -0.006, 95% confidence interval [CI] = -0.018 to -0.001; effectCoT = -0.009, 95%CI = -0.022 to -0.001; unstandardized coefficients), with the indirect effects of sleep disturbance accounting for less than 5% of the total direct and indirect effects. Frequency of short sleeps was not a significant mediator. WTC reduces the risk of subsequently being involved in an accident, although sleep may not be a strong component of the mechanism underlying this association.

Both sleep loss and social stress are risk factors for health and performance ability. It is assumed that sleep and stress are bidirectional linked, but most of the previous research has focused on studying sleep problems as consequence of stress. We believe that it is important to improve our understanding of the reverse connection, which is less studied. This presentation will cover recent experimental human studies that have investigated how sleep loss affects stress responses and whether it makes individuals more vulnerable to psychosocial stress. A study by Minkel et al. (Health Psychology, 2014) reported that the cortisol response to an acute stress situation was increased after sleep deprivation compared with a control condition indicating a more pronounced activation of the hypothalamic-pituitary-adrenal stress axis. I will also present recently collected data from young (18–30 years) and older (60–72 years) subjects that participated in four conditions (between subject design): (i) normal night sleep. (ii) normal night sleep & acute stress (Trier Social Stress Test). (iii) total sleep deprivation. (iv) total sleep deprivation & acute stress. The presentation thus provides state of the art knowledge of the link between sleep loss and vulnerability to stress., The authors work is supported by a grant from the Bank of Sweden Tercentenary Foundation (P13-0649:1).

This review summarises the literature on shift work and its relation to insufficient sleep, chronic diseases, and accidents. It is based on 38 meta-analyses and 24 systematic reviews, with additional narrative reviews and articles used for outlining possible mechanisms by which shift work may cause accidents and adverse health. Evidence shows that the effect of shift work on sleep mainly concerns acute sleep loss in connection with night shifts and early morning shifts. A link also exists between shift work and accidents, type 2 diabetes (relative risk range 1.09-1.40), weight gain, coronary heart disease (relative risk 1.23), stroke (relative risk 1.05), and cancer (relative risk range 1.01-1.32), although the original studies showed mixed results. The relations of shift work to cardiometabolic diseases and accidents mimic those with insufficient sleep. Laboratory studies indicate that cardiometabolic stress and cognitive impairments are increased by shift work, as well as by sleep loss. Given that the health and safety consequences of shift work and insufficient sleep are very similar, they are likely to share common mechanisms. However, additional research is needed to determine whether insufficient sleep is a causal pathway for the adverse health effects associated with shift work.

This study aimed to examine the association between polysomnographic sleep and subjective habitual sleep quality and restoration from sleep. Thirty-one normal sleepers completed the Karolinska Sleep Questionnaire and multiple home polysomnography recordings (n = 2-5). Using linear regression, sleep quality and restoration were separately analyzed as functions of standard polysomnography parameters: sleep efficiency, total sleep time, sleep latency, stage 1 and 2 sleep, slow-wave sleep, rapid eye movement sleep, wake time after sleep onset, and awakenings (n), averaged across recordings. Stage 2 and slow-wave sleep predicted worse and better sleep quality, respectively. Also, slow-wave sleep predicted less subjective restoration, although adjustment for age attenuated this relation. Our findings lend some physiological validity to ratings of habitual sleep quality in normal sleepers. Data were less supportive of a physiological correlate of ratings of restoration from sleep.

Employees have gained increased flexibility in organizing their work in time and space, that is boundaryless work. Managing the boundaries between work and personal life would seem to be crucial if one is to psychologically detach from work during leisure in order to unwind and get sufficient sleep. Drawing from a sample of Swedish professional workers (N = 3,846), a theoretical model was proposed testing the inter-relationships between boundaryless work in time and space, weekly work hours, psychological detachment, sleeping problems and sleep duration using a structural equation modelling (SEM) analysis. Findings showed that working boundlessly in time, that is spread out during the working day and week, was directly associated with both long weekly work hours and lack of psychological detachment. In contrast, working boundlessly in space, that is at several different places, was inversely associated with weekly work hours and had no association with psychological detachment. Psychological detachment, in turn, was directly associated with sleeping problems and inversely associated with sleep duration. Sleeping problems were inversely associated with sleep duration. Employees with long weekly work hours had a low degree of sleeping problems. There was also no association between long weekly work hours and sleep duration. These findings contradict earlier research, however, we interpret these findings as that if one works a great deal but is able to mentally detach from work-related feelings and thoughts during free time, then sleep will not be hampered because perseverative cognitions associated with prolonged biological activation will have been interrupted. As such, psychological detachment can be regarded as the mechanism that mediates the relationships between working 'anytime' and long weekly work hours, and sleep. It was concluded working boundlessly in time increases the likelihood for long weekly work hours and lack of psychological detachment. Hence, emplo, The authors gratefully acknowledge AFA (120083) for financing this study.

Den här kunskapssammanställningen tar sin utgångspunkt i den (starka) könssegregeringen på svensk arbetsmarknad och vilken betydelse den har för skillnader i organisatoriska och psykosociala omständigheter för kvinnor och män. Den beskriver kunskapsläget vad gäller likheter och skillnader mellan kvinnor och män med fokus på organisatoriska faktorer (som arbetstid och anställningsvillkor) samt psykosociala arbetsmiljöfaktorer i form av upplevda krav och resurser. Dessa faktorers betydelse för kvinnors och mäns psykiska ohälsa, självrapporterade hälsa, arbetsrelaterade välbefinnande samt sjukskrivning beaktas i kunskapssammanställningen. Utgångspunkt tas i offentlig statistik om arbetsskador och sjuktal, med fokus på ”kvinnodominerade” branscher som vård, skola och omsorg. Rapporten beskriver forskningsläget utifrån internationell och nationell vetenskaplig litteratur från det senaste decenniet., Rapporten är resultat av ett uppdrag från Arbetsmiljöverket genomfört av forskare på Stockholms universitet, Psykologiska institutionen och Stressforskningsinstitutet. Arbetsmiljöverket finansierade rapporten.

Airline pilots' sleep and on-duty alertness are important focus areas in commercial aviation. Until now, studies pertaining to this topic have mainly focused on specific characteristics of flights and thus a comprehensive picture of the matter is not well established. In addition, research knowledge of what airline pilots actually do to maintain their alertness while being on duty is scarce. To address these gaps in research knowledge, we conducted a field study on a representative sample of the airline pilots of a medium-sized airline. The sample consisted of 90 pilots, of whom 30 flew long-haul (LH) routes, 30 short-haul (SH) routes, and 30 flew both. A total of 86 pilots completed the measurements that lasted for almost two months per pilot. The measurements resulted in a total of 965 flight duty periods (FDPs) including SH flights and 627 FDPs including LH flights. During the measurement periods, sleep was measured by a diary and actigraphs, on-duty alertness by the Karolinska Sleepiness Scale (KSS) in all flight phases, and on-duty alertness management strategies by the diary. Results showed that SH and LH FDPs covering the whole domicile night (00:00-06:00 at home base) were most consistently associated with reduced sleep-wake ratio and subjective alertness. Approximately every 3rd FDP falling into this category involved a reduced sleep-wake ratio (1:3 or lower) and every 2nd a reduced level of subjective alertness (KSS rating 8-9 in at least one flight phase). The corresponding frequencies for the SH and LH FDPs that partly covered the domicile night were every 10th and every 5th FDP and for the pure non-night FDPs every 30th and every 36th FDP, respectively. The results also showed that the pilots tended to increase the use of effective on-duty alertness management strategies (consuming alertness-promoting products and taking strategic naps) in connection with the FDPs that overlapped the domicile night. Finally, the results showed that the frequency of flig

The Karolinska Sleepiness Scale (KSS) is frequently used to study sleepiness in various contexts. However, it exists in two versions, one with labels on every other step (version A), and one with labels on every step (version B) on the 9-point scale. To date, there are no studies examining whether these versions can be used interchangeably. The two versions were here compared in a 24 hr wakefulness study of 12 adults. KSS ratings were obtained every hour, alternating version A and B. Results indicated that the two versions are highly correlated, do not have different response distributions on labeled and unlabeled steps, and that the distributions across all steps have a high level of correspondence (Kappa = 0.73). It was concluded that the two versions are quite similar.

Driving while sleepy is associated with increased crash risk. Rumble strips are designed to alert a sleepy or inattentive driver when they deviate outside their driving lane. The current study sought to examine the effects of repeated rumble strip hits on levels of physiological and subjective sleepiness as well as simulated driving performance. In total, 36 regular shift workers drove a high-fidelity moving base simulator on a simulated road with rumble strips installed at the shoulder and centre line after a working a full night shift. The results show that, on average, the first rumble strip occurred after 20 min of driving, with subsequent hits occurring 10 min later, with the last three occurring approximately every 5 min thereafter. Specifically, it was found that the first rumble strip hit reduced physiological sleepiness; however, subsequent hits did not increase alertness. Moreover, the results also demonstrate that increased subjective sleepiness levels, via the Karolinska Sleepiness Scale, were associated with a greater probability of hitting a rumble strip. The present results suggest that sleepiness is very resilient to even strongly arousing stimuli, with physiological and subjective sleepiness increasing over the duration of the drive, despite the interference caused by rumble strips.

In this cross-sectional study associations were examined between eight shift schedule characteristics with shift-specific sleep complaints and need for recovery and generic health and performance measures. It was hypothesized that shift schedule characteristics meeting ergonomic recommendations are associated with better sleep, need for recovery, health and performance. Questionnaire data were collected from 491 shift workers of 18 companies with 9 regular (semi)-continuous shift schedules. The shift schedule characteristics were analyzed separately and combined using multilevel linear regression models. The hypothesis was largely not confirmed. Relatively few associations were found, of which the majority was in the direction as expected. In particular early starts of morning shifts and many consecutive shifts seem to be avoided. The healthy worker effect, limited variation between included schedules and the cross-sectional design might explain the paucity of significant results.

Driver fatigue has received increased attention during recent years and is now considered to be a major contributor to approximately 15-30% of all crashes. However, little is known about fatigue in city bus drivers. It is hypothesized that city bus drivers suffer from sleepiness, which is due to a combination of working conditions, lack of health and reduced sleep quantity and quality. The overall aim with the current study is to investigate if severe driver sleepiness, as indicated by subjective reports of having to fight sleep while driving, is a problem for city based bus drivers in Sweden and if so, to identify the determinants related to working conditions, health and sleep which contribute towards this. The results indicate that driver sleepiness is a problem for city bus drivers, with 19% having to fight to stay awake while driving the bus 2-3 times each week or more and nearly half experiencing this at least 2-4 times per month. In conclusion, severe sleepiness, as indicated by having to fight sleep during driving, was common among the city bus drivers. Severe sleepiness correlated with fatigue related safety risks, such as near crashes.