Ludovic G. P. M. van Amelsvoort

Need for recovery from work: evaluating short-term effects of working hours, patterns and schedules

In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week generally went together with more need for recovery from work. Overtime work was particularly associated with higher need for recovery from work in both genders. Both male and female three-shift or irregular shift workers had higher odds of elevated need for recovery compared to day workers. When additionally controlling for work-related factors, need for recovery levels among shift workers substantially lowered. This study clearly showed that working hours and schedules are associated with need for recovery from work, with different associations for men and women. Especially the associations between work schedules and need for recovery from work were very interrelated with other work-related factors. Future studies could further investigate the possibility that shift work might function as a proxy of other work-related factors that explain the different levels in need for recovery from work, or that job demands are perceived higher among shift workers and may therefore lead to more need for recovery from work.

DEPRESSED MOOD IN THE WORKING POPULATION: ASSOCIATIONS WITH WORK SCHEDULES AND WORKING HOURS

The impact of working time arrangements (WTA) on health has been studied extensively. Still, little is known about the interrelation between work schedules, working hours, and depressed mood. For work schedules, the underlying assumptions regarding depressed mood refer to a disturbance of social and biological rhythms, whereas for working hours, the assumptions relate to workload and work capacity. Conversely, depressed mood may urge an employee to adjust his/her work schedule and/or number of working hours/week (h/wk). The aim of this study was to assess the association between work schedule and working hours with depressed mood. Using baseline data from the Maastricht Cohort Study, depressed mood in day work was compared with depressed mood in different shiftwork schedules (n = 8843). Within day work, several categories of working h/wk were studied in association with depressed mood (n = 7217). The association between depressed mood and several aspects of overtime was assessed separately. Depressed mood was measured with a dichotomous item: “Did you feel down every day over the last two weeks?” Separate logistic regression analyses were conducted for men and women, with adjustments for potential confounders. The odds ratio (OR) for depressed mood was greater for men involved in shiftwork than for men only involved in day work (three-shift OR = 2.05 [95% confidence interval, CI 1.52–2.77]; five-shift OR = 1.34 [95% CI 1.00–1.80]; irregular-shift OR = 1.79 [95% CI 1.27–2.53]). In female employees, five-shift work was associated with a higher prevalence of depressed mood (OR = 5.96 [95% CI 2.83–12.56]). Regarding the number of working h/wk, men working <26 h/wk had a higher prevalence of depressed mood than men working 36–40 h/wk (OR = 2.73 [95% CI 1.35–5.52]). After conducting trend analyses, a significant decreasing trend was found in men, whereas an increasing trend was found in women working a high number of hours. Furthermore, a dose-response relationship was present in men regarding the number of overtime h/wk. This study showed that different work schedules and working hours are associated with depressed mood. Shiftwork was related to a higher prevalence of depressed mood than day work. The association was more pronounced for male employees. Regarding the number of working h/wk, male and female employees showed an opposite trend in depressed mood. Because of the possibility of a healthy worker effect and the possibility of a reciprocal relationship between WTA and depressed mood, the reported relation might be underestimated. This study has illustrated that occupational physicians, who deal with depressed mood among workers, should carefully consider the impact of WTA. (Author coorespondence: Karolien.Driesen@epid.unimaas.nl)

Differences in fatigue and psychological distress across occupations: results from the Maastricht Cohort study of fatigue at work

Differences in fatigue and psychological distress across occupations were examined among 8521 employees participating in the Maastricht Cohort Study of “Fatigue at Work.” Additional information on the perceived psychosocial work environment was incorporated. A total of 131 occupations, classified according to the Netherlands Standard Classification of Occupations 1992, were studied. Results showed that occupation as a proxy index of the “objective” work environment adds little explanatory information beyond perceived measures of the work environment. Although “occupation” seems to be an easy entree for intervention, focusing on occupation exclusively to prevent, or at least reduce, fatigue and psychological distress may be inadequate. Supplementary information about the perceived work environment of the job occupant is needed to develop preventive measures on the individual level. Further research, including a longitudinal analysis, is required to elucidate the complex relation between occupation, psychosocial risk factors, and fatigue and psychological distress.

Chronic bronchitis, cigarette smoking, and the subsequent onset of depression and anxiety: results from a prospective population-based cohort study.

Objective: The authors used data from a prospective, population-based cohort study to examine: (a) whether the presence of chronic bronchitis predicts the subsequent onset of depression or anxiety, and (b) if the incidence of depressed or anxious cases was different for smokers compared with nonsmokers. Materials and Methods: For studying the relation between chronic bronchitis and anxiety or depression, we used data from respectively 4468 and 4520 respondents. Results: The number of incident anxious (19.1%, n = 17) and depressed (14.0%, n = 13) cases was highest in employees with chronic bronchitis compared with employees without respiratory complaints (4.3%, n = 189 and 3.3%, n = 145, respectively). The presence of chronic bronchitis was associated with a significant increase in anxious and depressed cases (odds ratio (OR) for anxiety = 5.09, 95% confidence interval (CI) 2.91, 8.89; OR for depression = 4.38, 95% CI 2.35, 8.16). The incidence of anxiety as well as depression was strongest in the smokers group (OR for anxiety = 8.94, 95% CI 4.08, 19.59; OR for depression = 7.56, 95% CI 3.37, 16.96). Conclusions: This prospective study shows significantly higher levels of anxiety as well as depression in employees with chronic bronchitis. Results also seem to indicate that smoking cigarettes modifies this association, resulting in an increased risk of depression and anxiety in employees with chronic bronchitis who smoke. COPD = chronic obstructive pulmonary disease; HADS = Hospital Anxiety and Depression Scale; HADS-A = HADS anxiety subscale; HADS-D = HADS depression subscale.

The association between chronic diseases and fatigue in the working population

OBJECTIVE The aims of this study were to examine (a) whether employees with a chronic disease report more fatigue than employees without a chronic disease, (b) whether number or type of chronic disease is related to fatigue, and (c) whether differences in fatigue level in various types of chronic diseases are related to psychological distress. METHODS Data were taken from 12,137 employees. Fatigue was measured with the Checklist Individual Strength (CIS). RESULTS Employees with a chronic disease reported more fatigue (OR=2.9, 95% CI=2.7-3.2). Small differences were observed in the level of fatigue in various types of diseases. A strong linear association between the number of chronic diseases and fatigue was found. Psychological distress explained the higher level of fatigue in some chronic diseases (gastrointestinal diseases and migraine). CONCLUSIONS Fatigue is more common in employees with a chronic disease. A strong association between number of chronic diseases and fatigue exists. Fatigue in employees with a chronic disease can partly be explained by psychological distress. Some chronic diseases show a stronger association between psychological distress and fatigue.

A weight of evidence approach to causal inference

OBJECTIVE The Bradford Hill criteria are the best available criteria for causal inference. However, there is no information on how the criteria should be weighed and they cannot be combined into one probability estimate for causality. Our objective is to provide an empirical basis for weighing the Bradford Hill criteria and to develop a transparent method to estimate the probability for causality. STUDY DESIGN AND SETTING All 159 agents classified by International Agency for Research of Cancer as category 1 or 2A carcinogens were evaluated by applying the nine Bradford Hill criteria. Discriminant analysis was used to estimate the weights for each of the nine Bradford Hill criteria. RESULTS The discriminant analysis yielded weights for the nine causality criteria. These weights were used to combine the nine criteria into one overall assessment of the probability that an association is causal. The criteria strength, consistency of the association and experimental evidence were the three criteria with the largest impact. The model correctly predicted 130 of the 159 (81.8%) agents. CONCLUSION The proposed approach enables using the Bradford Hill criteria in a quantitative manner resulting in a probability estimate of the probability that an association is causal.

The incidence of anxiety and depression among employees - the role of psychosocial work characteristics

Background: Anxiety and depression are prevalent among employees and are associated with functional disability and work impairment. To date, little is known about the incidence and possible risk factors for developing anxiety and depression in the working population. Study aims were to (a) determine the incidence of subclinical anxiety and depression in a general working population and (b) identify the psychosocial work characteristics associated with the onset of subclinical anxiety and depression. Methods: This prospective study is based on 3,707 employees participating in the Maastricht Cohort Study on Fatigue at Work. Psychosocial work characteristics were measured in May 2000; anxiety and depression were measured with the Hospital Anxiety and Depression Scale in April 2002. Results: The cumulative 23‐month incidence for subclinical anxiety and depression was 4.6 and 3.3%, respectively. High psychological job demands increased the risk for both subsequent anxiety and depression. Moreover, low social support was predictive for the onset of anxiety, whereas job insecurity increased the risk for the onset of depression. These prospective associations were independent of potential confounding variables and the other psychosocial work characteristics. Conclusions: Adverse psychosocial work characteristics are significant predictors for the onset of subclinical anxiety and depression in the general working population. These findings encourage intervention studies testing whether modifying the psychosocial work environment reduces both anxiety and depressive symptoms among employees. Depression and Anxiety 26:1040–1048, 2009.

Association between n-3 fatty acid status in blood and electrocardiographic predictors of arrhythmia risk in healthy volunteers ☆

pattern of the inferior-posterior wall. This abnormality likely occurs because of external compression of the inferoposterior wall by an elevated diaphragm, which in turn is caused by high intra-abdominal pressures from organomegaly and/or ascites. Paradoxical inferior-posterior wall motion should not be confused with ischemia or intrinsic abnormality of the myocardium on echocardiography. Furthermore, it should alert the echocardiographer of the possible presence of elevated intra-abdominal pressures and advanced liver disease.

Psychological distress and depressed mood in employees with asthma, chronic bronchitis or emphysema: A population-based observational study on prevalence and the relationship with smoking cigarettes

Objectives: To evaluate if employees with asthma, chronic bronchitis or emphysema can be characterized as a population of patients with a high prevalence of psychological distress and/or depressed mood. Above all, we wanted to examine the influence of smoking status on the relationship between chronic disease and psychological distress/depressed mood. Methods: A postal survey was conducted among 12,103 employees participating in the Maastricht Cohort Study. Results: Smoking employees, who reported having asthma, chronic bronchitis or emphysema were more likely to report suffering from depressed mood compared to smokers with no long-lasting disease (prevalence rate, PR: 29.3 and 9.0%, respectively; OR for depressed mood = 4.04; 95% CI: 2.56–6.39) and when compared to smoking employees with a history of heart disease, hypertension or myocardial infarction (PR: 18.1%; OR: 1.99; 95% CI: 1.07–3.68), or rheumatoid arthritis (PR: 20.1%; OR: 1.73; 95% CI: 0.96–3.11). Conclusion: These findings provide health care professionals with additional evidence regarding the importance for including the assessment of psychological distress and depressed mood in the routine evaluation of the patient with asthma, chronic bronchitis or emphysema, especially with regard to smoking cessation.

Effects of job insecurity from a workplace closure threat on fatigue and psychological distress.

The aim of this study was to prospectively investigate the effect of potential workplace closure, an externally attributed form of job insecurity, on fatigue and psychological distress. In April 1999, the minister responsible announced that a governmental agency would close down one of its two locations. Baseline data from the employees were available before the closure announcement (n = 574) because they were enrolled in the Maastricht Cohort Study on “Fatigue at Work.” In the closure group, the relative risk for becoming a psychological distress case was 1.61 (95% confidence interval [CI] = 1.27–2.05) during 13 months after the closure threat. Within the closure group, a difference in relative risk for psychological distress was observed between employees who self reported an increase in job insecurity (relative risk = 1.85; 95% CI = 1.41–2.42) and employees who did not report an increase in job insecurity (relative risk 1.14; 95% CI = 0.58–2.24)