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Introduction Shift work has been associated with sleepiness. Sleepiness from shift work may increase the risk of occupational injuries, but could also continue outside of work and increase risk of injury during commuting and leisure time. In this study, we assessed the associations between evening shifts, night shifts and quick returns, and risk of occupational, transport and leisure-time injuries. Material and method We used a case-crossover design to compare characteristics of the shift right before an injury with shifts in previous control periods (i.e. without an injury) within the same individual. Shift information was derived from the Danish Working Hour Database (DWHD) and linked to information on injuries from The National Patient Register. The study populations included a total of 13 337 occupational injuries, 2722 transport injuries and 9768 leisure-time injuries. Data were analysed by conditional logistic regression. Results In the adjusted analyses, the odds of an occupational injury were higher during evening compared with day shifts (OR 1.54, 95%CI 1.43–1.66) and quick returns compared with regular returns (OR 1.26, 95%CI 1.10–1.44). No higher odds of a leisure-time injury or leisure time transport injury were observed after evening shift or night shifts vs. day shifts, or quick returns vs. regular returns. Conclusion Our findings support the evidence of a higher risk of occupational injuries during evening shifts and after quick returns. Findings on leisure-time transport and commuting injuries were inconclusive, while we found no support for a higher risk of injury during leisure-time after evening shifts, night shifts or quick returns.

Background: The World Health Organization (WHO) and the International Labour Organization (ILO) are developing a joint methodology for estimating the national and global work-related burden of disease and injury (WHO/ILO joint methodology), with contributions from a large network of experts. In this paper, we present the protocol for two systematic reviews of parameters for estimating the number of deaths and disability-adjusted life years from depression attributable to exposure to long working hours, to inform the development of the WHO/ILO joint methodology. Objectives: We aim to systematically review studies on occupational exposure to long working hours (Systematic Review 1) and systematically review and meta-analyse estimates of the effect of long working hours on depression (Systematic Review 2), applying the Navigation Guide systematic review methodology as an organizing framework, conducting both systematic reviews in tandem and in a harmonized way. Data sources: Separately for Systematic Reviews 1 and 2, we will search electronic academic databases for potentially relevant records from published and unpublished studies, including Medline, EMBASE, Web of Science, CISDOC and PsycINFO. We will also search electronic grey literature databases, Internet search engines and organizational websites; hand search reference list of previous systematic reviews and included study records; and consult additional experts. Study eligibility and criteria: We will include working-age (≥15 years) participants in the formal and informal economy in any WHO and/or ILO Member State, but exclude child workers (, The publication was prepared with financial support from the World Health Organization cooperative agreement with the Centres for Disease Control and Prevention National Institute for Occupational Safety and Health of the United States of America on implementing Resolution WHA 60.26 “Workers' Health: Global Plan of Action” (Grant 1 E11 OH0010676-02).

Background: Workplace bullying may severely affect mental health, but its association with suicidal behaviour is unknown. We analysed whether individuals reporting exposure to workplace bullying had higher risk of suicidal behaviour than those not reporting such exposure. Methods: Using a prospective cohort study design, we linked data from nine Danish questionnaire-based surveys (2004-2014) to national register data until December 31st, 2016. Exposure to workplace bullying was measured by a single item. Suicide attempts were identified in hospital registers and death by suicide in the Cause of Death Register. Among participants with no previous suicide attempts, we estimated Hazard Ratios (HR) and 95% Confidence Intervals (CI), adjusting for sex, age, marital status, socio-economic status, and history of psychiatric morbidity. Outcomes: The sample consisted of 98 330 participants (713 809 person-years); 63·6% women, mean age 44·5 years. Workplace bullying was reported by 10 259 participants (10·4%). During a mean follow-up of 7·3 years, we observed 186 cases of suicidal behaviour, including 145 suicide attempts, 36 deaths by suicide and 5 cases that died by suicide after surviving a suicide attempt. The fully-adjusted HR for the association between workplace bullying and suicidal behaviour was 1·70 (95% CI 1·10–2·61). The HRs for suicide attempts and death by suicide were 1·72 (1·14–2·58) and 2·29 (1·00–5·53), respectively. A multiplicative interaction with sex (2·78, CI 1·59–4·88) indicated that workplace bullying was associated with suicidal behaviour among men. Interpretation: The results suggested an elevated risk of suicidal behaviour among men reporting workplace bullying. Funding Information: Region of Southern Denmark (grant number A1763); Danish Working Environment Research Fund (grant number 20130023294); Danish Working Environment Research Fund (grant number 10-2019-03). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The project has been approved by the Danish Data Protection Agency (Capital Region of Denmark; j.nr.: 2012-58-0004).

This study aimed to examine the extent to which allostatic load (AL), measured in midlife, mediates the association between educational attainment in young adulthood and self-rated health (SRH) in midlife among women and men. The study used data from the Copenhagen Aging and Midlife Biobank (CAMB; n = 5467 participants, aged 48-62 years, 31.5% women). Educational attainment was assessed as years of education. SRH was assessed with one item: 'In general, how would you say your health is?' with response options from "excellent" to "poor". AL mediated 31.7% and 19.7% of the association between educational attainment and SRH in women and men, respectively. We observed that higher educational attainment was associated with better SRH and lower AL in both women and men. Our study showed that AL partly mediates the association between educational attainment in young adulthood and SRH in adulthood among both men and women. This study indicates that educational attainment in young adulthood affects health throughout life. Such knowledge of a potential mediator may be important in breaking the social heritage.

This paper explores whether occupational safety and health (OSH) risk perceptions, behaviour and exposure differ among Emergency Department (ED) doctors, nurses and medical secretaries, and whether observed safe working conditions and behaviour in EDs vary across work shifts. Staff from four public hospital-based EDs completed a survey regarding safety climate, risk behavior, work pressure, exposure to and reporting of injuries, violence and threats. Furthermore, safety observations of working conditions (e.g. order and tidiness) and behavior (e.g. discarding hypodermic needles) were carried out during day, evening and night shifts. Rates of self-reported violence and threats in ED doctors and nurses were two to three times greater than rates seen for doctors and nurses at hospitals in general. However, ED respondents perceived a greater managerial focus on certain aspects of the safety climate. Work pressure and lack of time (among doctors and nurses) and social pressure (among medical secretaries) were the primary reasons given for taking OSH risks. If OSH incidents (e.g. injuries or violence) were not reported, it was often because the process was perceived as too laborious, and some incidents were considered ‘part of the job’. Observations of order and tidiness in the EDs showed a gradual lower score in safety conditions from the day to the evening and night shift. Multifaceted and integrated interventions for educating and training ED personnel need to take into account their varying risk exposures, perceptions and behaviors in creating and sustaining an efficient, safe and healthy working environment.

We aimed to test the hypotheses that night-shift work is associated with an increased incidence of (i) redeemed prescriptions for psychotropic medicine and (ii) psychiatric hospital treatment due to mood, anxiety or stress-related disease. Moreover, we aimed to assess whether (iii) the effect of night-shift work on the rates of antidepressants differs from the effects on the rates of anxiolytics and (iv) the association between night-shift work and psychotropic medicine is affected by long working hours.Full-time employees who participated in the Danish Labor Force Survey sometime in the period 2000-2013 (N=131 321) were followed for up to five years in national registers for redeemed prescriptions and psychiatric hospital treatment. The analyses were controlled for sex, age, weekly working hours, calendar time of the interview and socioeconomic status.We detected 15 826 cases of psychotropic drug use in 521 976 person-years at risk and 1480 cases of hospitalization in 636 673 person-years at risk. The rate ratio (RR) for psychotropic drugs was estimated to be 1.09 [99% confidence interval (CI) 1.02-1.16] for night-shift versus no night-shift work. The corresponding RR for psychiatric hospital treatment was 1.11 (95% CI 0.95-1.29). The odds of redeeming a prescription for antidepressants rather than anxiolytics was independent of night-shift work: 1.09 (95% CI 0.96-1.24), and we found no interaction effect between night-shift work and working hours (P=0.26).As it appears in the general working population in Denmark, night-shift work is not an important predictor of mental ill health.

This study aims at 1) examining the effect of self-rostering on emotional demands, quantitative demands, work pace, influence, social community at work, social support from leaders and colleagues, job satisfaction, and negative acts, 2) examining whether this effect was mediated through increased influence on the scheduling of working hours, and interpreting the results in light of the different implementation processes that emerged in the study and by including qualitative data. We conducted a 12 months follow-up, quasi-experimental study of self-rostering among 28 workplaces out of which 14 served as reference workplaces. We also interviewed 26 employees and 14 managers about their expectations of introducing self-rostering. In the present study implementation of self-rostering had a positive effect on job demands and the social environment of the workplace, especially if the intervention does not comprise drastic changes of the organisation of the employees' work and private life.

Is has long been established, that views to natural scenes can a have a dampening effect on physiological stress responses. However, as people in Europe, Canada and North America today spent 50-85% of their time indoors, attention might also be paid to how the artificial man-made indoor environment influences these mechanisms. The question that this study attempts to start addressing is therefore whether certain design, characteristics of indoor spaces can make a difference to the physiological stress response as well. Using a virtual version of the Trier Social Stress Test, in which the space is computer generated and properties of the space therefore can be systematically varied, we measured saliva cortisol and heart rate variability in participants in a closed room versus a room with openings. As shown by a significant linear contrast interaction between groups and TSST conditions, participants in the closed room responded with more pronounced cortisol reactivity to stress induction, and continued to show higher levels throughout recovery, compared to participants in the open room. No differences were found regarding any part of the autonomic nervous system.

Summary Background Work related fatigue has been suggested as a link in the assumed sequence of events between repeated adverse work demands and the development of work related stress, which may be associated with changes in concentrations of cortisol, psychological overload and, in the long run, health problems. Insufficient sleep is a contributing factor to lack of recovery, but previous studies on associations between subjective aspects of sleep and recovery, and cortisol, have been inconclusive. The aim with the present study was to examine possible associations between cortisol measures and (I) self-rated recovery, (II) occupational fatigue and (III) subjective sleep quality the night preceding cortisol sampling. Further, possible gender differences were tested. Methods Salivary cortisol was measured in 581 persons during a working day, at awakening, +30 min and in the evening. Various measures of subjective sleep and recovery were analyzed in relation to cortisol. Results Few correlations between cortisol and any sleep- or recovery parameters were found. However, some significant associations were found between cortisol and a few measures of more chronic aspects of sleep and recovery. Gender stratified analyses showed somewhat differing associations among men and women. This indicates that possible associations and pathways between lack of recovery/sleepiness and cortisol, and in the long run, unhealth, may not be similar for men and women.

The aim of the present intervention study was to examine if increased influence on working hours among shift workers led to better sleep quality. 391 employees were categorized into groups based on the performed activities: High (self-rostering), moderate (education and/or policy for working hours), and low intensity intervention (meetings and discussions) and reference. Sleep quality was assessed by Karolinska Sleep Questionnaire (KSQ) at baseline and follow-up (12 months). To elucidate the process of the intervention interviews were conducted. Influence on one's own working hours increased only in the high intensity group (p < 0.001). No effects of interventions on sleep quality were observed. Thus, sleep quality was not improved by increasing work time influence in the present group of Danish elder care workers. This was partly due to program failure (failed intervention), but may also be due to other factors such as few participants working night and few working full time.

Previous studies indicate that the effect of a given shift schedule may depend on individual factors. The aim of the present study was to investigate whether a misfit between individual preferences and actual working hours affected the association between working hours and self-reported indicators of health and well-being. The study population consisted of 173 female eldercare workers who mainly worked day or evening shifts. We combined self-reported questionnaire data on preferences with actual work schedules during a four-week period. The study showed that a misfit between preferences on one hand and "non-day work", "weekend work" or "only a few consecutive days off" on the other hand was associated with an increased dissatisfaction with working hours and/or an increase in the intention to leave the workplace due to one's working hours.

In occupational health studies, the study groups most often comprise healthy subjects performing their work. Sampling is often planned in the most practical way, e.g., sampling of blood in the morning at the work site just after the work starts. Optimal use of reference intervals requires that the population, on which the reference interval is based, is representative for the study group in question. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommends estimating reference interval on at least 120 subjects. It may be costly and difficult to gain group sizes of that order of magnitude for all topics in question. Therefore, new methods to estimate reference intervals for small sample sizes are needed. We present an alternative method based on variance component models. The models are based on data from 37 men and 84 women taking into account biological variation from various variables such as gender, age, BMI, alcohol, smoking, and menopause. The reference intervals were compared to reference intervals calculated using IFCC recommendations. Where comparable, the IFCC calculated reference intervals had a wider range compared to the variance component models presented in this study. The presented method enables occupational health researchers to calculate reference intervals for specific groups, i.e. smokers versus non-smokers, etc. In conclusion, the variance component models provide an appropriate tool to estimate reference intervals based on small sample sizes.

The relationships among bullying or witnessing bullying at work, self-reported health symptoms, and physiological stress reactivity were analysed in a sample of 437 employees (294 women and 143 men). Physiological stress reactivity was measured as cortisol in the saliva. Of the respondents, 5% of the women (n=15) and 5% of the men (n=7) reported bullying, whereas 9% of the women (n=25) and 11% of the men (n=15) had witnessed bullying at work. The results indicated that the bullied respondents had lower social support from coworkers and supervisors, and they reported more symptoms of somatisation, depression, anxiety, and negative affectivity (NA) than did the nonbullied respondents. Witnesses reported more symptoms of anxiety and lower support from supervisor than did the nonbullied employees. Concentrations of cortisol in the saliva were lower at awakening in bullied respondents compared with nonbullied respondents. Previous studies have reported lower diurnal concentration of cortisol for people with posttraumatic stress disorder (PTSD) and chronic fatigue. To our knowledge, this is the first full study on the associations among being subjected to bullying, health outcomes, and physiological stress response.

A competitive ELISA with an inhibition step for the determination of serum keratan sulphate (KS), was validated using bovine corneal KS as standard. The method was shown to be in statistical control. The recovery was 85% (S.D.=2.2%), hence the obtained results had to be corrected. The limit of detection (LOD) was 1.4 μg m l−1. Intra-assay CV was 3.0% (n=15) for samples used for method evaluation and 6.0% (n=18) for serum samples. Inter-assay CV was 7.0% for high KS level samples (CKS=31.2 μg m l−1) and 16.0% for low KS level samples (CKS=5.9 μg m l−1) based on the S.D.y/x from the method evaluation function and 10% (high KS level) and 16% (low KS level) based on serum samples. Validation of the method was performed using the serum samples from 102 healthy individuals. There was a statistical difference in serum KS levels between men and women, but no age related differences. Tentative biological reference intervals for men and women were established. It was also shown that due to the large between-subject variability in KS levels, the preferable monitoring strategy is to use individuals as their own controls where possible.

A radioimmunoassay (RIA) for total corticosterone (CORT) in rat plasma requiring a plasma volume of 2 μl was established. The importance of inactivating plasma corticosteroid-binding globulin (CBG), denatured by heat, before measuring CORT was shown. The method was evaluated and shown to be within analytical and statistical controls, with a recovery not significantly different from 100%. The limit of detection (LD) was 0.2 μg dl −1 . Intra-assay coefficients of variation (CVs) were 7.2% for plasma samples at 33.5 μg dl −1 CORT ( n =10) and 8.5% at 0.75 μg dl −1 CORT ( n =18). Inter-assay CVs were 6.8% at 23.1 μg dl −1 CORT ( n =8) and 5.4% at 8.9 μg dl −1 CORT ( n =8). Validation of the method was performed using a group of male rats (Mol:WIST Han; M & B A/S, Denmark; n =12), housed under conventional environmental conditions from the age of 4 weeks. The rats were 3 and 7/2 months old when they underwent the blood sampling procedure. The result showed that the method had a capacity to detect CORT concentrations comparable with previous reported basal concentrations. Finally, the possible stress inducing effect of the blood sampling procedure was examined using two groups of male rats housed under either conventional or enriched environmental conditions. The result indicated that conventional environment housing induces slightly stressed animals compared to enriched housing. Enriched housing may provide an environment that makes it possible for rats to compensate for a stressful situation, i.e., the blood sampling procedure.