The aim of this study was to describe the effects of sleep loss on behavioural and subjective indicators of sleepiness on a road containing a milled rumble strip in the centre of the lane. Particular attention was paid to behavioural and subjective indicators of sleepiness when using the centre lane rumble strip, and to possible erratic driving behaviour when hitting a rumble strip. In total 9 regular shift workers drove during the morning hours after a full night shift and after a full night sleep. The order was balanced. The experiment was conducted in a moving base driving simulator on rural roads with a road width of 6.5 and 9 meters. Out of the 1,636 rumble strip hits that occurred during the study, no indications of erratic driving behaviour associated with the jolt caused by making contact with the centre lane rumble strip could be found. Comparing the alert condition with the sleep deprived condition, both the standard deviation of lateral position (SDLP) and the Karolinska Sleepiness Scale (KSS) increased for sleepy drivers. For the two road widths, the drivers drove closer to the centre line on the 6.5-meter road. The KSS and the SDLP increased with time on task. This simulator study indicates that rumble strips in the centre of the lane may be an alternative to centreline and edgeline rumble strips on narrow roads.
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.
The study objective was to investigate the impact of different kinds of organizational changes, as well as anticipation of such changes, on work-related stress, sleep, recovery and health. It was hypothesized that impaired sleep and recovery increase the adverse health consequences of organizational changes. The data consisted of cross sectional questionnaire data from a random sample of 1,523 employees in the Swedish police force. It could be shown that extensive organizational changes including downsizing or a change in job tasks were associated with a small increase in work stress, disturbed sleep, incomplete recovery and health complaints. However, less extensive organizational changes like relocation did not affect these outcome variables. Anticipation of extensive organizational changes had almost the same effect as actual changes. Furthermore a moderating effect of sleep and work stress on gastrointestinal complaints and depressive symptoms was found. Thus, like former studies already suggested, extensive organizational changes resulted in increased stress levels, poorer health and impaired sleep and recovery. Furthermore, organizational instability due to anticipation of changes was as negative as actual changes. There was also some evidence that disturbed sleep increased these adverse health effects, in particular with respect to anticipation of organizational changes.
Interventions and strategies to improve health through the management of circadian (re) adaptation have been explored in the field, and in both human and animal laboratory manipulations of shiftwork. As part of an initiative by the Working Time Society (WTS) and International Committee on Occupational Health (ICOH), this review summarises the literature on the management of circadian (re) adaption using bright light treatment. Recommendations to maximise circadian adaptation are summarised for practitioners based on a variety of shiftwork schedules. In slowly rotating night shift schedules bright light appears most suitable when used in connection with the first three night shifts. These interventions are improved when combined with orange glasses (to block blue-green light exposure) for the commute home. Non-shifting strategies involve a lower dosage of light at night and promoting natural daylight exposure during the day (also recommended for day shifts) in acordance with the phase and amplitude response curves to light in humans.
Potential effects of shift work on health are probably related to the misalignment between the light-dark cycle and the human activity-rest cycle. Light exposure at night mediates these ef- fects, including social misalignment and leads to an inversion of activity and rest, which, in turn, is linked to changes in behaviours. This article reviews the epidemiological evidence on the association between shift work and health, and possible mechanisms underlying this association. First, evidence from findings of the meta-analyses and systematic reviews published in the last 10 yr is presented. In addition, it reports the larger single-occupation studies and recent large population- based studies of the general workforce. Koch’s postulates were used to evaluate the evidence related to the development of disease as a result of exposure to shift work. Finally, we discussed limitations of the multiple pathways that link shift work with specific disorders and the methodological challenges facing shift work research. We concluded that the clearest indications of shift work being the cause of a disease are given when there is a substantial body of evidence from high quality field studies showing an association and there is good evidence from laboratory studies supporting a causal explanation of the link.
Improved work organisation could be of importance for decreased bullying in workplaces. Participants in the Swedish Longitudinal Occupational Survey of Health (SLOSH) responded to questions about work and workplace and whether they had been bullied during the past year in 2006. Those in worksites with at least five employees who did not report that they had been bullied in 2006 and without workplace change between 2006 and 2008 constituted the final sample (n=1,021 men and 1,182 women). Work characteristics and workplace factors in 2006 were used in multiple logistic regression as predictors of bullying in 2008. Separate analyses were performed for work characteristics and workplace factors respectively. Adjustments for demographic factors were made in all analyses. The question used for bullying was: Are you exposed to personal persecution by means of vicious words or actions from your superiors or your workmates? Such persecution any time during the past year was defined as bullying. For both genders organisational change and conflicting demands were identified as risk factors, and good decision authority as a protective factor. Dictatorial leadership, lack of procedural justice and attitude of expendability were male and lack of humanity a female risk factor for bullying.
Few studies have considered the work environment in relation to workplace conflicts and those who have been published have included relatively few psychosocial work environment factors. Little research has been published on the consequences of workplace conflicts in terms of employee health. In this study, the statistical relationships between work and workplace characteristics on one hand and conflicts on the other hand are examined. In addition, the relationship between conflicts at work and self-rated health are described. The study population was derived from the Swedish Longitudinal Occupational Survey of Health (SLOSH) 2006; n=5,141. Among employees at workplaces with more than 20 employees (n=3,341), 1,126 (33.7%) responded that they had been involved in some type of conflict during the two years preceding the survey. Among the work and workplace characteristics studied, the following factors were independently associated with increased likelihood of ongoing conflicts: Conflicting demands, emotional demands, risk of transfer or dismissal, poor promotion prospects, high level of employee influence and good freedom of expression. Factors that decreased the likelihood of ongoing conflicts were: Good resources, good relations with management, good confidence in management, good procedural justice (fairness of decisions) and good social support. After adjustment for socioeconomic conditions the odds ratio for low self-rated health associated with ongoing conflict at work was 2.09 (1.60-2.74). The results provide a good starting point for intervention and prevention work.
Given the well-known difficulties in defining and detecting fatigue, it is a real challenge to incorporate it into either traffic or criminal law. Finnish traffic law forbids fatigued driving "only" on a general level concerning the driver's fitness to drive. We present several comments from Finnish traffic and local police officers regarding their own experiences of driving while fatigued. The comments were extracted from a larger survey of traffic (N=129) and local (N=100) police officers, and prosecutors (N=96). Although the main topic of the survey was the application of the law that forbids fatigued driving, some police officers raised the issue of their own behavior in this respect. We argue that many shift workers, including police officers, break the law, especially when driving home after a night shift.
Professional heavy vehicle drivers can experience a traumatic event at work when suicidal drivers deliberately crash into their vehicles or a pedestrian jumps in front of them. This study adopts a qualitative approach, aiming to gain an understanding about the psychological and other consequences that these crashes have for this occupational group. We organized a semi-structured focus group meeting with six drivers who reported experiencing a deliberate crash into their vehicle. The meeting was moderated by two psychologists. The participants reported that avoiding the crash was difficult. These events can have long-lasting effects on drivers’ well-being although individual differences in the response to the event and coping strategies do exist. Participation in our meeting was regarded as a positive experience. This encourages us to believe that organizing similar meetings that allow drivers under the supervision of professionals to share their own experiences with those who experienced similar events, could perhaps be one way of providing support to such drivers who experienced a traumatic event at work.
Long-term sickness absence has doubled in Sweden, as has complaints of disturbed sleep. The present study sought to investigate the prospective link between long-term sickness absence and disturbed sleep or fatigue. Sleep and fatigue from a representative national sample was followed up 1.5-2 yr later in terms of return from long-term (>or=90 d) and intermediate term (14-89 d) sickness absence. 8,300 individuals participated in the survey, out of which 372 were on long-term and 1,423 were on intermediate term sick leave. The data was analyzed using logistic regression analysis with adjustment for background and work environment variables. Separate analyses were carried out for disturbed sleep and fatigue since they were correlated. The results showed that those with disturbed sleep at the start had an Odds Ratio (OR) of 0.56 (95% Confidence Interval (CI)=0.35-0.90) for returning from long-term sickness absence. For fatigue the results were OR=0.56 (CI=0.34-0.90). Intermediate term sickness absence showed similar, but slightly weaker, results. The results indicate that disturbed sleep and fatigue are predictors of lack of return from long term and intermediate term sickness absence.
Despite the common notion that stress impairs sleep there is little published data showing that sleep (polysomnography [PSG]) is impaired across several sleep episodes in individuals who complain of daily stress during the same period. The present paper aimed at investigating such a connection. 33 subjects had 3 sleeps recorded with PSG at home across 6 weeks and kept a sleep/wake diary each day, including 3-hourly ratings of stress (scale 1-9). The stress ratings and the conventional PSG parameters were averaged across time. A stepwise multiple regression analysis showed that the best predictors of stress were Stage 1 sleep (beta=0.49), latency to Stage 1 sleep (0.47) (adjusted for anxiety and age). Other sleep continuity variables had significant correlations with stress (reversed) but did not enter the multiple regression analysis. The correlation between stress before the start of the study and PSG data was not significant. It was concluded that moderately increased stress over a longer period of time is related to moderate signs of disturbed sleep during that period. This may be of importance when considering stress as a work environment problem.
Short rest (<11h) between evening and day shifts – known as quick returns (QRs) – impede recovery and may impair health. Nevertheless, QRs remain popular among some shift workers. This study explores nurses’ and nursing assistants’ perceptions of the merits and demerits of QRs from individual and organizational perspectives. Participants were recruited from eleven wards at two Swedish hospitals as part of a larger quasi-experimental intervention study. The majority (79%) had influence over their work schedules. Frequency distributions of responses are presented. Ninety six undertook a baseline survey regarding recovery, tolerance and work performance in relation to QRs. A majority experienced difficulties unwinding before bedtime (76%), insufficient sleep (80%), and daytime fatigue (72%). A third experienced an increased risk of errors and mistakes. However, QRs appeared to facilitate taking reports from patients and planning work, as this task was more often rated as ‘very easy’ following a QR compared to other shift combinations. Tolerance of QRs varied substantially. In conclusion, QRs seem to benefit continuity in work processes, but may do so at the expense of recovery and safety. Wards planning to reduce QRs –through participatory or fixed schedule models – should consider impacts on work processes.