Labour market affiliation among non-bullied colleagues at work units with reported bullying.

AIM: This study investigates if non-bullied employees in Work units (WUs) where bullying occur, are more prone to leave the WUs than employees in WUs with no bullying, and if the prevalence of workplace bullying had an impact on leaving the WUs. Leaving the workplace was defined by unemployment or change of workplace at follow-up. METHODS: We had data from 8326 Danish public health invited employees from 302 WUs. Of these 3036 responded to a questionnaire on working conditions and health in 2007. WUs were classified into three categories of WUs: (1) no bullying (0% bullied), (2) moderate prevalence of bullying (< 10% bullied), and (3) high prevalence of bullying (≥ 10% bullied). Bullied respondents were used to classify the WUs and excluded in the analyses. RESULTS: We found odds ratios (ORs) for unemployment 1 year later of 1.27 [95% CI 0.69-2.37] in WUs with moderate prevalence of bullying and 1.38 [95% CI 0.85-2.23] among employed in WUs with high prevalence of bullying, adjusted for size of WUs, age, sex, and job category. For turnover 1 year later the ORs were 1.27 [95% CI 0.78-2.15] and 1.46 [95% CI 0.99-2.15] in WUs with moderate and high prevalence of bullying, respectively. CONCLUSION: We did not find that non-bullied employees leave the WUs with moderate and high prevalence of bullying more than employees in WUs with no bullying behaviour 1 year later. Leaving the workplace tended to be higher among employees in WUs with high prevalence of bullying compared to no and moderate bullying.

Physical and psychosocial work factors as explanations for social inequalities in self-rated health.

OBJECTIVE: We investigated the contribution of physical and psychosocial work factors to social inequalities in self-rated health (SRH) in a sample of Danish 40 and 50 years old occupationally active women and men. METHODS: In this longitudinal study, the study population consisted of 3338 Danish women and men. Data were collected by postal questionnaires in 2000 (baseline) and 2006 (follow-up). The independent variable, socioeconomic position (SEP), was assessed by the highest achieved educational level at baseline. We conducted gender-stratified parallel multiple mediation analyses. In the mediation analyses, SEP was categorised as SEP I, II, III, VI and V among men. Among women, SEP was dichotomised into SEP I-IV and V. The outcome, SRH, was assessed at baseline and follow-up. A wide range of physical and psychosocial work factors were included as potential mediators. RESULTS: We found a social gradient in SRH across all levels of SEP among men. Among women, we only found a poorer SRH among those with the lowest SEP. Mediation analyses showed that work factors together accounted for 56% of the social inequalities in SRH among men and 44% among women. In both genders, ergonomic exposures and job insecurity seemed to play the major role for social inequalities in SRH. For women only, we also found noise to contribute to the social inequalities in SRH. CONCLUSION: Physical and psychosocial work factors partially explained social inequalities in SRH among both genders. Improvement of the working environment can potentially contribute to the reduction of social inequalities in health.

The longitudinal association between shift work and headache: results from the Danish PRISME cohort.

PURPOSE: We investigated the effect of shift work on headache. Furthermore, we investigated whether the association between shift work and headache was explained by potential mediators in terms of perceived stress, poor sleep and health behaviors. METHODS: In this longitudinal study, we used questionnaire data (collected in 2007 and 2009) from civil servants and hospital employees from the PRISME study. 2952 individuals were available for the analyses of shift work and headache and 2272 individuals were available for the analyses of shift work and migraine. Headache was operationalized as the participants' experience of "being bothered by headache during the past 4 weeks". Migraine was operationalized as "ever being diagnosed with migraine by a medical doctor". We used binary logistic regression to compare shift workers with permanent day workers and adjusted for socio-demographic factors. In a subsequent step, we adjusted for potential mediators. RESULTS: We found higher odds of unspecific headache (OR = 1.25; 95% CI 1.02-1.54) and migraine (OR = 1.72; 95% CI 1.04-2.86) among shift workers compared with day workers. Our results suggest that the effect of shift work on headache and migraine differ between men and women. Inclusion of potential mediators in the analyses did not attenuate the associations. CONCLUSION: Shift workers have higher risk of reporting being bothered by headache as well as reporting being diagnosed with migraine. Future research is needed to disentangle the underlying mechanisms with the aim of reducing headache related to occupational exposures.

Perceived stress and dementia: Results from the Copenhagen city heart study.

Objectives: We investigated if perceived stress in midlife increased the risk of dementia. Furthermore, we explored differences between subgroups related to sex, age and employment status when reporting stress.Methods: In this longitudinal study, we used information on perceived stress from 10,814 participants (mean age 56.7 years). Participants were followed through Danish national registers for development of dementia. Participants were considered at risk of dementia from the date they turned 60 years. Perceived stress was assessed as a combination of self-reported intensity and frequency of stress, and categorized into low (score 0-1), medium (score 2-4), and high stress (score 5-6). We used Poisson regression to estimate incidence rate ratios (IRR) and their 95% confidence intervals (CI) and adjusted for sociodemographic factors and psychiatric morbidity at baseline (main model) as well as cardio/cerebrovascular diseases and health behaviors at baseline (additional model).Results: The mean follow-up time was 13.8 years, and 1,519 participants were registered with dementia. Dementia risk was higher in participants reporting medium stress (IRR = 1.11, 95% CI: 0.99-1.24) and high stress (IRR = 1.36, 95% CI: 1.13-1.65). Adjustment for cardio/cerebrovascular diseases and health behaviors did not alter the results. We did not find strong support for differences between subgroups, although the association between stress and dementia was stronger for those who were employed at the time of reporting high stress.Conclusion: Our results provide empirical support for an effect of perceived stress on the risk of dementia in old age.

Emotional demands and exhaustion: cross-sectional and longitudinal associations in a cohort of Danish public sector employees.

PURPOSE: To examine cross-sectional and longitudinal associations between content-related emotional demands at work and exhaustion, and to investigate if these associations were modified by other psychosocial work characteristics. METHODS: In 2007, 4489 Danish public service employees participated in the PRISME study by completing postal questionnaires, and 3224 participated in the follow-up in 2009. Content-related emotional demands were measured by a scale (scored 1 to 5) based on five work-content-related items, and exhaustion was measured with the general exhaustion scale from the Copenhagen Burnout Inventory (CBI) (scored 1 to 5). The cross-sectional and longitudinal associations with exhaustion were analysed in the same model and adjusted for effects of potential confounders. Effect modifications were examined separately for self-reported emotional enrichment, meaningful work, job control, social support at work and quantitative demands. RESULTS: Exhaustion increased with increasing emotional demands, both cross-sectionally and longitudinally. However, although statistically significant, the effect was small. In the longitudinal analysis, a one unit increase in emotional demands was associated with a 0.03 unit (95% CI: 0.01-0.06) increase in exhaustion. We found statistically significant effect modification for three of six potentially modifying work characteristics. The effect of emotional demands on exhaustion was lower for participants with high levels of emotional enrichment (cross-sectionally and longitudinally), high levels of meaningful work (longitudinally), and higher for high levels of quantitative demands (cross-sectionally). CONCLUSIONS: Increasing content-related emotional demands were associated with increasing levels of exhaustion, cross-sectionally and longitudinally. This effect was reduced if the work was experienced as emotionally enriching and meaningful.

A cohort study on self-reported role stressors at work and poor sleep: does sense of coherence moderate or mediate the associations?

AIM: The aim of the present study was to examine the bidirectional associations between subjective role ambiguity and role conflicts at work, respectively, and self-reported sleep 2 years later. In addition, we also examine whether sense of coherence (SOC) moderate or mediate the association between role stressors and poor sleep and between poor sleep and role stressors. METHODS: We used questionnaire data collected in 2006 and 2008 from the Workplace Bullying and Harassment cohort. In 2006, 3363 responded to the questionnaire and in 2008 1671 responded. In total, 1569 participants responded in both 2006 and 2008 to the questions on role stressors (in terms of role ambiguity and role conflicts at work) and sleep problems in both 2006 and 2008. Sleep problems were assessed with the awakening index (AWI) and the disturbed sleep index (DSI). Moderation and mediation analyses of the association were estimated using structural equation modelling. RESULTS: We found a prospective association between role stressors and sleep problems [beta values were 0.07 (95% CI 0.03-0.11) and 0.05 (CI 0.01-0.10) for DSI and AWI, respectively] when adjusting for sleep problems at baseline, age, sex, and life style factors (i.e. alcohol, smoking, and leisure time physical activity). SOC moderated the association showing that participants with lower SOC scores who reported higher role ambiguity reported sleep problems to a higher extent than participants with high SOC scores. SOC also mediated the association between role stressors and sleep problems. We also found support for sleep problems at baseline and role stressors 2 years later [DSI 0.04 (CI 0.00-0.08) and 0.15 (CI 0.09-0.21)] for role ambiguity and role conflicts, respectively. Similar results were observed for AWI. CONCLUSION: Subjective role stressors were prospectively associated with sleep problems. Yet, sleep problems could also prospectively predict subjective role stressors (i.e. reverse causation). The analyses also showed that SOC may be regarded as both a mediating and a moderating factor of the association between subjective role conflicts and poor sleep. We found that SOC moderated the prospective association so participants with low SOC report more sleep problems with subjective role conflicts compared to participants with high SOC. Finally, we also found SOC mediated the prospective association between subjective role stressors and sleep problems and the reverse association.

Prolonged perceived stress and saliva cortisol in a large cohort of Danish public service employees: cross-sectional and longitudinal associations.

PURPOSE: It is well known that acute stress can lead to a transient increase in cortisol secretion, but the effects of prolonged stress on cortisol secretion are uncertain. This study examines the cross-sectional and longitudinal associations between prolonged perceived stress and salivary cortisol. METHODS: In 2007, 4467 Danish public service employees participated in a study of stress and mental health, and 3217 participated in a follow-up in 2009. Perceived stress during the past 4 weeks was assessed by Cohen's four item perceived stress scale. Participants were asked to collect saliva 30 min after awakening and at approximately 20:00 in the evening. The cortisol dependence on perceived stress was examined in regression analyses adjusted for effects of potential confounders. We adjusted for a large variation in saliva sampling times by modelling the time trajectory of cortisol concentrations in the morning and in the evening and examined if they were influenced by perceived stress. RESULTS: Perceived stress had no statistically significant effects on the level or time trajectory of morning or evening cortisol, neither cross-sectionally nor longitudinally. The 1 month prevalence of frequently perceived stress was low, approximately 2.5%. CONCLUSION: Our results did not support the hypothesis that prolonged perceived stress is associated with the level or time trajectory of morning or evening salivary cortisol.

Occupational noise exposure, psychosocial working conditions and the risk of tinnitus.

PURPOSE: The purpose of this study was to evaluate the influence of occupational noise (current and cumulative doses) and psychosocial work factors (psychological demands and decision latitude) on tinnitus occurrence among workers, using objective and non-self-reported exposure measures to prevent reporting bias. METHODS: In a cross-sectional study, we analyzed data from a Danish survey from 2009 to 2010 that included 534 workers from children day care units and 10 manufacturing trades. Associations between risk factors (current noise exposure, cumulative noise exposure and psychosocial working conditions) and tinnitus were analyzed with logistic regression. RESULTS: We found no statistically significant associations between either current [OR 0.95 (95% CI 0.89; 1.01)] or cumulative [OR 0.93 (95% CI 0.81; 1.06)] occupational noise exposure and tinnitus. Likewise, results for psychosocial working conditions showed no statistically significant association between work place decision latitude [OR 1.06 (95% CI 0.94; 1.13)] or psychological demands [OR 1.07 (95% CI 0.90; 1.26)] and tinnitus. CONCLUSIONS: Our results suggest that current Danish occupational noise levels (in combination with relevant noise protection) are not associated with tinnitus. Also, results indicated that the psychosocial working conditions we observed in this cohort of mainly industrial workers were not associated with tinnitus. Therefore, psychosocial working conditions comparable to those observed in this study are probably not relevant to take into account in the evaluation of workers presenting with tinnitus.

The associations between workplace bullying, salivary cortisol, and long-term sickness absence: a longitudinal study.

BACKGROUND: Workplace stressors, such as bullying, are strongly related to subsequent long-term sickness absence, but little is known of the possible physiological mechanisms linking workplace stressors and sickness absence. The primary aim of this study was to investigate to what extent cortisol levels were associated with subsequent sickness absence and if cortisol mediated the association between workplace bullying and sickness absence. We additionally investigated possible bidirectional associations between bullying, cortisol, and long-term sickness absence. METHODS: Participants came from two Danish cohort studies, the "Psychosocial RIsk factors for Stress and MEntal disease" (PRISME) cohort and the "Workplace Bullying and Harassment" (WBH) cohort (n = 5418). Information about exposure to workplace bullying and morning and evening salivary cortisol was collected at three time points with approximately two years in between. After each data collection, all participants were followed for two years in registers, and cases with long-term sickness absence lasting 30 or more consecutive days were identified. The association between cortisol levels and subsequent sickness absence was assessed by logistic regression, while the extent to which the association between bullying and sickness absence was mediated by cortisol was quantified through natural direct and indirect effects. RESULTS: High evening cortisol was associated with a decreased risk of sickness absence (OR = 0.82, 95% CI = 0.68-0.99), but we did not find that high morning cortisol levels (OR = 0.98, 95% CI = 0.81-1.18) or high morning-to-evening slope (OR = 0.99, 95% CI = 0.82-1.18) were associated with subsequent sickness absence. We also tested for reverse causation and found that long-term sickness absence, but not salivary cortisol, was a strong risk factor for subsequent workplace bullying. There was no indication that cortisol mediated the association between workplace bullying and sickness absence. CONCLUSION: We found no straightforward and simple association between cortisol and long-term sickness absence. Furthermore, the association between workplace bullying and long-term sickness absence was not mediated by cortisol.

The association between workplace bullying and depressive symptoms: the role of the perpetrator.

BACKGROUND: The aim of the present study was to investigate whether the depressive symptoms of the bullied respondents differed according to who the perpetrator was. METHODS: We used cross-sectional questionnaire data from two representative cohorts: the Danish Working Environment Cohort Study (DWECS 2010) and the Work and Health Study (WH 2012). After excluding respondents not having a leader, or being self-employed, assisting spouses, and those reporting multiple perpetrators in WH 2012, the statistical analysis included 2478 bullied individuals. We compared respondents reporting being bullied by their (1) leader, (2) subordinates, (3) clients / customers / patients / students, or (4) colleagues, respectively. The occurrence of depressive symptoms was measured by the Major Depression Inventory (MDI). RESULTS: The most frequent perpetrator of bullying was clients (41.5 %) in DWECS 2010 and colleagues (60.3 %) in WH 2012. In DWECS 2010, the MDI score of those being bullied by clients were significantly lower than the MDI scores of the other groups. In WH 2012, respondents who reported bullying from leaders had a significantly higher mean MDI score than participants being bullied by colleagues. Also in WH 2012, our results indicated that those who were bullied by leaders had a higher MDI score than those bullied by clients, although this difference was not statistically significant at conventional levels. CONCLUSION: Our findings indicated a similar pattern in the two cohorts, with a tendency of more severe depressive symptoms among employees who are exposed to bullying by their leaders, and the least severe symptoms among those who are bullied by clients.

The role of poor sleep in the relation between workplace bullying/unwanted sexual attention and long-term sickness absence.

PURPOSE: While exposure to bullying and unwanted sexual attention was previously found to increase the risk of sickness absence, the underlying mechanisms are largely unknown. Poor sleep can be a consequence of stressful exposures and a cause of poor health, and poor sleep is also a determinant of insufficient recovery. Therefore, the present study investigated whether poor sleep mediates and/or moderates the association between bullying and unwanted sexual attention, on the one hand, and long-term sickness absence (LTSA), on the other hand. METHODS: We used questionnaire data from 7650 individuals contributing with 15,040 2-year observation periods. Workplace bullying, unwanted sexual attention, disturbed sleep, and difficulties awakening were measured at three time points, and participants were followed in registers to measure the occurrence of LTSA, defined as ≥30 consecutive days of sickness absence during the subsequent 2 years. RESULTS: The odds of LTSA were significantly increased by workplace bullying (OR 1.77; 95 % CI 1.50-2.12) and unwanted sexual attention (OR 1.55; 95 % CI 1.06-2.29). Together, disturbed sleep and difficulties awakening mediated 12.8 % (95 % CI 8.1-19.8) of the association between bullying and long-term sickness absence, and 8.5 % (95 % CI -0.45 to 37.1) of the association between unwanted sexual attention and long-term sickness absence in the fully adjusted model. Neither disturbed sleep nor difficulties awakening moderated these associations. CONCLUSION: As expected, bullying and unwanted sexual attention were prospectively associated with long-term sickness absence. Only a small part of this association was mediated by poor sleep.

Self-reported workplace bullying and subsequent risk of diagnosed mental disorders and psychotropic drug prescriptions: A register-based prospective cohort study of 75,252 participants.

BACKGROUND: Evidence concerning workplace bullying as a risk factor for mental disorders is currently limited to depressive disorders and mainly based on non-clinical assessments. This study aims to examine the prospective association of self-reported workplace bullying with different types of register-based hospital-diagnosed mental disorders and redeemed psychotropic drug prescriptions. METHODS: Using a cohort study design, we examined a pooled dataset of 75,252 participants from 14 questionnaire-based surveys conducted between 2004 and 2014. In the questionnaires, workplace bullying was measured by a single item. The questionnaires were linked to Danish registers on hospital-diagnosed mental disorders and redeemed psychotropic drug prescriptions up to 2016. Data were analysed by multivariate Cox proportional hazard models, including only participants without a history of mental disorders or prescriptions since 1995. RESULTS: After adjustment for sex, age, marital and socio-economic status, workplace bullying was associated with an excess risk of any mental disorder (HR 1.37; 95 % CI: 1.17-1.59) as well as mood disorders and neurotic, stress-related, and somatoform disorders. In stratified analyses, this association were statistically significant only among women. Workplace bullying was also associated with any psychotropic drug prescription (fully-adjusted HR 1.43; 95 % CI: 1.35-1.53). This association was observed in both sexes and for all prescriptions, including anxiolytics, hypnotics and sedatives, antidepressants, and nootropics. LIMITATIONS: Firm conclusions about sex-related differences cannot be drawn. Residual confounding by unmeasured factors such as personality cannot be ruled out. CONCLUSIONS: Workplace bullying was associated with higher risks of diagnosed mental disorders among women and psychotropic drug prescriptions in both sexes.

Work-unit measures of organisational justice and risk of depression--a 2-year cohort study.

OBJECTIVES: The aim of this study is to analyse if low justice at work, analysed as aggregated workplace means, increases the risk of depression. METHODS: A total of 4237 non-depressed Danish public employees within 378 different work units were enrolled in 2007. Mean levels of procedural and relational justice were computed for each work unit to obtain exposure measures that were robust to reporting bias related to depression. Two years later in 2009, 3047 (72%) participated at follow-up. Those reporting high levels of depressive, burn-out or stress symptoms were assigned to a psychiatric diagnostic interview. In the interview 58 cases of new onset depression were identified. Depression ORs by work unit level of procedural and relational justice were estimated by multivariable logistic regression accounting for established risk factors for depression. RESULTS: Working in a work unit with low procedural justice (adjusted ORs of 2.50, 95% CI 1.06 to 5.88) and low relational justice (3.14, 95% CI 1.37 to 7.19) predicted onset of depression. CONCLUSIONS: Our results indicate that a work environment characterised by low levels of justice is a risk factor for depression.

Workplace bullying and risk of suicide and suicide attempts: A register-based prospective cohort study of 98 330 participants in Denmark.

OBJECTIVES: The aim of this study was to analyze whether individuals reporting exposure to workplace bullying had a higher risk of suicidal behavior, including both suicide attempt and death by suicide, 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 registers up to 31 December 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, socioeconomic status, and history of psychiatric morbidity. RESULTS: The sample consisted of 98 330 participants (713 798 person-years), 63.6% were women, and the mean age was 44.5 years. Of these participants, 10 259 (10.4%) reported workplace bullying. During a mean follow-up of 7.3 years, we observed 184 cases of suicidal behavior, including 145 suicide attempts, 35 deaths by suicide and 4 cases that died by suicide after surviving a suicide attempt. The fully-adjusted HR for the association between workplace bullying and suicidal behavior was 1.65 (95% CI 1.06-2.58). The HR for suicide attempts and death by suicide were 1.65 (1.09-2.50) and 2.08 (0.82-5.27), respectively. Analyses stratified by sex showed a statistically significant association between workplace bullying and suicidal behavior among men but not women. CONCLUSIONS: The results suggest that exposure to workplace bullying is associated with an elevated risk of suicidal behavior among men.

The Effect of Psychosocial Work Factors on Headache: Results From the PRISME Cohort Study.

OBJECTIVE: To investigate the cross-sectional and longitudinal association between psychosocial work factors, assessed as work-unit averages, and headache. For comparison, we also applied individual exposure measures. METHODS: We used questionnaire-data on headache and psychosocial work factors (PWF). In total, 2247 employees were included in the cross-sectional analyses and 553 in the longitudinal analyses using work-unit averages. The corresponding numbers for the analyses using individual exposure measures were 4261 and 942 employees. RESULTS: Low skill discretion and low decision authority were most consistently associated with higher odds of headache across all analyses. Role conflicts, bullying, and effort-reward imbalance were associated with headache in some analyses. All PWF were associated with headache in cross-sectional analyses with individual exposure measures. CONCLUSION: This study partly supports the hypothesis of an effect of PWF, as a source of psychological stress, on the risk of headache.

Does Midlife Forgetfulness Influence Positive and Negative Aspects of Social Relations at Work?: Results From the Danish Working Environment Cohort Study.

OBJECTIVES: We investigated whether midlife forgetfulness was prospectively associated with changes in social relations at work (SRW) among occupationally active individuals in Denmark. METHODS: We analyzed data of 2339 men and women participating in the first (1990) and second (1995) survey of the Danish Work Environment Cohort Study, responding to questions on working environment, SRW, and forgetfulness. We used multiple linear regression analysis while adjusting for potential confounders. RESULTS: At baseline (1990), 517 (22.1%) study participants were categorized as forgetful. Forgetfulness was prospectively associated with a decline in one of the investigated items reflecting a negative aspect of SRW (experiencing teasing, regression coefficient = 0.07, 95% CI: 0.03 to 0.11), while no association was observed with positive aspects of SRW. CONCLUSIONS: Our findings did not support the hypothesis that memory problems such as midlife forgetfulness negatively affect SRW.

Vital Exhaustion and Incidence of Dementia: Results from the Copenhagen City Heart Study.

BACKGROUND: Psychological distress is potentially linked to the risk of dementia through neurologic and cardiovascular mechanisms. Vital exhaustion (VE) is a mental state of psychological distress, which could be a risk factor for dementia. OBJECTIVE: To investigate whether VE is a risk factor for dementia in later life. METHODS: We used data from 6,807 participants attending the third survey of the Copenhagen City Heart Study in 1991-1994. VE was assessed by 17 symptoms (score: 0-17) from the Maastricht Questionnaire. Information on dementia was obtained from national registers. Risk time for dementia was counted from five years after VE assessment for participants > 55 years at the time of VE assessment. For younger participants, risk time for dementia was counted from the year they turned 60 years and onwards. Participants were followed until 2016. We used Poisson regression to calculate incidence rate ratios (IRR) and their 95% confidence intervals (CI). RESULTS: During an average follow-up of 10 years, 872 participants were registered with dementia. We found a dose-response relation between the number of VE symptoms and the incidence of dementia. For every additional VE symptom, the dementia incidence increased by 2% (IRR = 1.024; 95% CI: 1.004-1.043). Adjustment for socio-demographic and health-related factors did not change the results substantially. Neither did stratification by age, sex, educational level, and marital status. CONCLUSION: We found evidence that VE is a risk factor for dementia. Our sensitivity analyses supported that this association was not only due to VE being a potential prodromal sign of dementia.

Night shift work, long working hours and dementia: a longitudinal study of the Danish Work Environment Cohort Study.

OBJECTIVE: Shift work and long working hours are potential risk factors for dementia, but previous studies on shift work, long working hours and dementia are sparse and their findings are conflicting. Therefore, we investigated the effect of night shift work and long working hours on dementia. DESIGN: A longitudinal study. SETTING: Denmark. PARTICIPANTS: 3435 occupationally active men and women from the general working population. METHODS: Work schedule covered day work (reference) and shift schedules without/with night work. Working hours covered <27, 28-36, 37 (reference), 38-44, and ≥45 hours/week. As the primary outcome, we used register-based information about dementia, and estimated incidence rate ratios (IRR) and 95% CI. Estimates were adjusted for gender, age, psychosocial work factors and cardiovascular risk factors. RESULTS: We identified 85 dementia cases during a mean of 9.8 years of follow-up. We found a positive, but statistically insignificant association between night shift work and dementia (IRR=2.01; 95% CI: 0.87-4.65). Post hoc analyses indicated that this was only due to a higher risk in permanent night workers (IRR=3.25; 95% CI: 1.35-7.83). The dementia risk was also significantly higher among participants working 38-44 hours/week (IRR=2.08; 95% CI: 1.11-3.90) compared with those working 37 hours/week. We found no indications of a higher risk of dementia in participants working <37 hours/week or ≥45 hours/week. CONCLUSION: We did not find arguments that night shift work or long working hours increased dementia risk in general. However, we found a higher risk of dementia in specific subgroups, that is, permanent night workers and employees with moderately longer weekly working hours than the standard.

Optimal Cut-Off Points for the Short-Negative Act Questionnaire and Their Association with Depressive Symptoms and Diagnosis of Depression.

Objectives: The behavioural experience method has been extensively used in the literature for the measurement of potential bullying behaviours at work. However, this approach presents limitations when used to classify respondents as targets or non-targets of workplace bullying. Therefore, the present study aimed to: (i) identify optimal cut-off points, reflecting a possible subjectively experienced exposure to occasional and frequent workplace bullying, for the 9-item Short Negative Act Questionnaire (S-NAQ), and (ii) examine the criterion validity of these cut-off points in relation to depressive symptoms and diagnosis of depression. Methods: The study was based on a sample of 4882 participants from the Danish MODENA cohort study (year 2011), which included both the S-NAQ (score range 9-45) and a one-item measure applying the self-labelling method with a definition to assess occasional and frequent workplace bullying. We employed receiver operating characteristic (ROC) curve analyses to derive the cut-off points for the S-NAQ. Based on these cut-off points, we created a new S-NAQ variable with three levels of exposure (i.e. 'not exposed', 'first threshold', and 'second threshold') and tested its criterion validity in relation to depressive symptoms (N = 4071) and diagnosis of depression (N = 4844). Results: The S-NAQ cut-off points obtained were ≥12 and ≥16 when using occasional and frequent bullying as reference standards, respectively. Both cut-off points showed high classification accuracy (area under the curve = 0.89 and 0.93) as well as good sensitivity (84.8% and 88.0%) and specificity (77.4% and 94.7%). In the adjusted linear regression analyses, both the first (B = 0.78, 95% confidence interval [CI] = 0.66-0.90) and the second threshold of exposure (B = 1.65, 95% CI = 1.44-1.86) were significantly associated with depressive symptoms. In the adjusted logistic regression analyses, both the first (odds ratio [OR] = 3.55, 95% CI = 1.98-6.38) and the second threshold of exposure (OR = 5.90, 95% CI = 2.93-11.88) were significantly associated with diagnosis of depression. Conclusions: The two cut-off points for the S-NAQ identified in this study showed a significant association with both depressive symptoms and diagnosis of depression. However, future prospective studies are needed to establish the predictive validity of the proposed cut-off points.

Does Workplace Bullying Affect Long-Term Sickness Absence Among Coworkers?

AIM: To examine if non-bullied employees at work units (WUs) with workplace bullying have more long-term sickness absence (LTSA) than employees in non-bullying WUs. METHODS: We included 7229 public health employees from 302 WUs and 3158 responders to a questionnaire on working conditions and health in 2007. WUs were classified into three categories of WUs; (1) no bullying (0% bullied); (2) moderate prevalence of bullying (less than 10% bullied); and (3) high prevalence of bullying (more than or equal to 10% bullied). LTSA (more than or equal to 30 consecutive days of sickness absence) during the following 2 years was obtained by linkage to the Danish register of sickness absence compensation benefits and social transfer payments. RESULTS: Non-bullied coworkers in WUs, where bullying was reported had 15% to 22% more LTSA compared with non-bullying WUs. CONCLUSION: Workplace bullying may be associated with LTSA in the entire WU.