P.M. Bongers

The Very Best of the Millennium: Longitudinal Research and the Demand-Control-(Support) Model

This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorells (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time lags, quality of measures, method of analysis, and nonresponse analysis. These criteria were applied to 45 longitudinal studies, of which 19 (42%) obtained acceptable scores on all criteria. These high-quality studies provided only modest support for the hypothesis that especially the combination of high demands and low control results in high job strain. However, good evidence was found for lagged causal effects of work characteristics, especially for self-reported health or well-being outcomes.

A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

This prospective four‐wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand–control history on the development of sleep quality and fatigue. Based on results of a four‐wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1‐year time lag, supporting the strain hypothesis (Demand–Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high‐strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep‐related complaints. Cumulative exposure to a low‐strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non‐high‐strain towards a high‐strain job was associated with a significant increase in sleep‐related complaints; conversely, a transition towards a non‐high‐strain job was not related to an improvement in sleep‐related problems.

Mindful "vitality in practice": an intervention to improve the work engagement and energy balance among workers; the development and design of the randomised controlled trial

BackgroundModern working life has become more mental and less physical in nature, contributing to impaired mental health and a disturbed energy balance. This may result in mental health problems and overweight. Both are significant threats to the health of workers and thus also a financial burden for society, including employers. Targeting work engagement and energy balance could prevent impaired mental health and overweight, respectively.Methods/DesignThe study population consists of highly educated workers in two Dutch research institutes. The intervention was systematically developed, based on the Intervention Mapping (IM) protocol, involving workers and management in the process. The workers needs were assessed by combining the results of interviews, focus group discussions and a questionnaire with available literature. Suitable methods and strategies were selected resulting in an intervention including: eight weeks of customized mindfulness training, followed by eight sessions of e-coaching and supporting elements, such as providing fruit and snack vegetables at the workplace, lunch walking routes, and a buddy system. The effects of the intervention will be evaluated in a RCT, with measurements at baseline, six months (T1) and 12 months (T2). In addition, cost-effectiveness and process of the intervention will also be evaluated.DiscussionAt baseline the level of work engagement of the sample was average. Of the study population, 60.1% did not engage in vigorous physical activity at all. An average working day consists of eight sedentary hours. For the Phase II RCT, there were no significant differences between the intervention and the control group at baseline, except for vigorous physical activity. The baseline characteristics of the study population were congruent with the results of the needs assessment. The IM protocol used for the systematic development of the intervention produced an appropriate intervention to test in the planned RCT.Trial registration numberNetherlands Trial Register (NTR): NTR2199

Internal consistency, test–retest reliability and concurrent validity of a questionnaire on work-related exposure related to arm, shoulder and neck symptoms in computer workers

The aim of this study was to determine the internal consistency, test–retest reliability and concurrent validity of the RSI QuickScan, a newly developed questionnaire that aims to identify the presumed risk factors for neck, shoulder and arm symptoms in a population of computer workers. The internal consistency was calculated using item analysis. The test–retest reliability and concurrent validity were analysed by calculating the percentage of agreement, Cohens Kappa and the Ppositive and Pnegative. The concurrent validity was also tested by comparing the results from the new questionnaire with those from the original questionnaires that the current questionnaire was based on, on-site expert observations and direct measurements. The results indicate that the RSI QuickScan is a measurement tool with acceptable internal consistency, reliability and concurrent validity. The questionnaire can be used as a means to rapidly collect data on a large population of office workers and at low cost.

Effects of a feedback signal in a computer mouse on movement behaviour, muscle load, productivity, comfort and user friendliness

To study the effects of a tactile feedback signal in a computer mouse on reduction of hovering behaviour and consequently on changes in muscle load, productivity, comfort and user friendliness, a comparative, experimental study with repeated measures was conducted. Fifteen subjects performed five trials with different mouse actions and a standardised task, once with a mouse with the feedback signal and once with a mouse without the feedback signal. Holding the hand just above the mouse caused higher muscle loading than clicking and scrolling. Holding the hand on the mouse caused higher muscle loading than resting the hand on the desk. The feedback signal effectively decreased hovering behaviour. It also led to a more dynamic activation pattern of the extensor muscles of the forearm. The overall opinion of the feedback signal for future use was rated as somewhat variable. No effects on discomfort or productivity were found. The use of a mouse with a tactile vibrating feedback signal seems promising for preventing arm complaints, although more research is needed to establish the clinical relevance.

An exploratory study of associations of physical activity with mental health and work engagement

BackgroundPrevious studies have found moderate to vigorous physical activity (MVPA) to be associated with a decreased risk of mental disorders. Although the focus in the field of psychology has shifted towards human strengths and optimal functioning, studies examining associations between MVPA and mental health in general (MH) and between MVPA and well-being are scarce. An indicator of work-related well-being is work engagement (WE). The aim of this study was to explore the associations between MVPA and MH, and between MVPA and WE.MethodsIn this study, a total of 257 employees from two research institutes, self-reported their MVPA, MH and level of WE. In addition, a randomly chosen subgroup (n=100) wore an Actigraph accelerometer for a 1-week period to measure their MVPA objectively. Crude and adjusted associations between MVPA and both WE and MH were analyzed using linear regression analyses.ResultsThere was no statistically significant association between self-reported MVPA and mental health, resulting from both the crude (b=0.058, 95% CI -0.118 - 0.235) and adjusted analyses (b=0.026; 95% CI -0.158- 0.210), nor between objectively measured MVPA and mental health for both crude and adjusted analyses (b=-0.144; 95% CI -1.315- 1.027; b=-0.199; 95% CI 1.417- 1.018 respectively). There was also no significant association between self-reported MVPA and work engagement (crude: b=0.005; 95% CI -0.005-0.016, adjusted: b= 0.002; 95% CI -0.010- 0.013), nor between objectively measured MVPA and work engagement (crude: b= 0.012; 95% CI -0.084- 0.060, adjusted: b=0.007; 95% CI -0.083-0.069).ConclusionsAlthough the beneficial effects of MVPA on the negative side of MH (i.e. mental disorders) have been established in previous studies, this study found no evidence for the beneficial effects of MVPA on positive side of MH (i.e. well-being). The possible difference in how the physical activity-mental health relationship works for negative and positive sides of MH should be considered in future studies.

The longitudinal association between multiple job holding and long-term sickness absence among Danish employees: an explorative study using register-based data

Background Multiple job holding (MJH) is common in many countries, but little is known about its (health) consequences. Our aim is to explore the longitudinal association between MJH and long-term sickness absence (LTSA) among Danish employees. Methods We included employees (n=8,968) who participated in the Danish Work Environment Cohort Study (DWECS), based on a representative sample of the Danish working population. Three dichotomous independent variables were created: MJH in general, combination MJH (i.e. second job as employee) and hybrid MJH (i.e. self-employed in second job). LTSA (≥5 weeks) was measured using the Danish Register for Evaluation of Marginalisation (DREAM) during 78 weeks of follow-up. Potential confounders included demographics, health, and work characteristics. Logistic regression analyses were performed to study whether LTSA was associated with MJH in general, combination MJH, and hybrid MJH. Interaction effects for gender, age, total working hours per week (≤37u2009or>37u2009hours a week) and shift work were tested. Results In total, 11.7% (n=1,048) of the respondents reported having multiple jobs and 7.6% (n=678) experienced LTSA during follow-up. After adjustment for confounders, no significant association between LTSA and MJH in general (OR=0.82), combination MJH (OR=0.81), or hybrid MJH (OR=0.83) was found. Among employees working more than 37u2009hours per week, combination MJH was associated with a higher likelihood of LTSA (OR=1.50). Conclusions We did not find evidence for an increased likelihood of LTSA among multiple job holders. Future research should study the likelihood of LTSA among subgroups of multiple job holders, e.g. those working long hours.