Estimation of Benchmark Dose as the Threshold Amount of Alcohol Consumption for Blood Pressure in Japanese Workers

In order to determine the threshold amount of alcohol consumption for blood pressure, we calculated the benchmark dose (BMD) of alcohol consumption and its 95% lower confidence interval (BMDL) in Japanese workers. The subjects consisted of 4,383 males and 387 females in a Japanese steel company. The target variables were systolic, diastolic, and mean arterial pressures. The effects of other potential covariates such as age and body mass index were adjusted by including these covariates in the multiple linear regression models. In male workers, BMD/BMDL for alcohol consumption (g/week) at which the probability of an adverse response was estimated to increase by 5% relative to no alcohol consumption, were 396/315 (systolic blood pressure), 321/265 (diastolic blood pressure), and 326/269 (mean arterial pressures). These values were based on significant regression coefficients of alcohol consumption. In female workers, BMD/BMDL for alcohol consumption based on insignificant regression coefficients were 693/134 (systolic blood pressure), 199/90 (diastolic blood pressure), and 267/77 (mean arterial pressure). Therefore, BMDs/BMDLs in males were more informative than those in females as there was no significant relationship between alcohol and blood pressure in females. The threshold amount of alcohol consumption determined in this study provides valuable information for preventing alcohol-induced hypertension.     

Associations between overtime and psychological health in high and low reward jobs

This study focused on the relationship between overtime and psychological health in high and low reward jobs, and in jobs with high and low external pressure to work overtime. Data were collected for 535 full-time employees of the Dutch Postal Service. In general, overtime was associated with negative work-home interference and negative home-work interference. Split-sample logistic regression analyses showed that employees reporting low rewards had elevated risks of burnout, negative work-home interference and slow recovery. In addition, the combination of overtime and low rewards was associated with negative home-work interference. A second analysis was conducted separately for employees who reported overtime in order to study the effects of external pressure to work overtime. In this subgroup, low rewards were associated with elevated risks of health complaints, emotional exhaustion and negative home-work interference. Moreover, employees who reported overtime and a high pressure to work overtime in combination with low rewards had elevated risks of poor recovery, cynicism, and negative work-home interference. The results suggest that even a limited number of hours of involuntary overtime is associated with adverse mental health, but only in low reward situations.     

Associations between overtime and psychological health in high and low reward jobs

This study focused on the relationship between overtime and psychological health in high and low reward jobs, and in jobs with high and low external pressure to work overtime. Data were collected for 535 full-time employees of the Dutch Postal Service. In general, overtime was associated with negative work-home interference and negative home-work interference. Split-sample logistic regression analyses showed that employees reporting low rewards had elevated risks of burnout, negative work-home interference and slow recovery. In addition, the combination of overtime and low rewards was associated with negative home-work interference. A second analysis was conducted separately for employees who reported overtime in order to study the effects of external pressure to work overtime. In this subgroup, low rewards were associated with elevated risks of health complaints, emotional exhaustion and negative home-work interference. Moreover, employees who reported overtime and a high pressure to work overtime in combination with low rewards had elevated risks of poor recovery, cynicism, and negative work-home interference. The results suggest that even a limited number of hours of involuntary overtime is associated with adverse mental health, but only in low reward situations.     

Sleep disturbances in shift-workers: A marker for maladaptation syndrome

Abstract

This study aims to examine whether the relationship between overtime and well-being is influenced by the voluntary vs. involuntary (i.e., compulsory) nature of overtime work and by the presence or absence of rewards for overtime. We also explored the prevalence of these types of overtime and how they were related to work and personal characteristics. A survey was conducted among a representative sample of Dutch full-time employees (N=1612). AN(C)OVA was used to compare rewarded and unrewarded, voluntary and involuntary overtime workers on personal and work characteristics, fatigue, and work satisfaction. Most overtime workers were rewarded (62%). About half of the sample (n=814) could be classified as either voluntary or involuntary overtime workers, or as having “mixed reasons” to work overtime. Voluntary and unrewarded overtime workers had a relatively high income and favourable job characteristics. Involuntary overtime work was associated with relatively high fatigue and low satisfaction, especially for involuntary overtime workers without rewards who can be considered a burnout risk group. Voluntary overtime workers were non-fatigued and satisfied, even without rewards. It can be concluded that control over overtime and rewards for overtime are important for well-being. Moderate overtime work may not be a problem if it is done voluntarily. Moreover, the negative effects of compulsory overtime work may be partly offset by fair compensation for the extra work.     

Psychological and physiological stress responses during repetitive work at an assembly line

The association between psychological and physiological stress responses was examined in 20 male workers at an assembly line. Each worker was studied during a 2 h period on two consecutive days in their normal job and, in order to obtain physiological baseline values, during a corresponding paid 2 h period off the job on the third day. Self-reports of work demands, mood, etc., measurements of catecholamine and cortisol excretion and of systolic and diastolic blood pressure and heart rate were obtained at the end of each of the three 2 h periods. Work induced a significant elevation in almost all psychological and physiological measurements. Levels were consistently lower in workers reporting a 'good' workday compared to those reporting a 'normal' or a 'bad' day. Correlations between self-reports and physiological values showed that catecholamine and cortisol responses, respectively, tended to be associated selectively with different psychological conditions, catecholamine values being associated with feelings of time pressure and pressure by demands, cortisol values with irritation, tenseness and tiredness. The results show that perceived stress at an assembly line is consistently reflected in cardiovascular and neuroendocrine functions of the workers.     

Rationalization in garages in the Netherlands and its effects on occupational health

In this study, various hypotheses were tested in relation to car mechanics working in a sample of domestic car garages in South Limburg, The Netherlands. These concerned the negative relationships between the degree of control over the work process, and occupational strain, blood pressure, skin disorders and problems in the locomotor system. The relevant intermediate variables used were task latitude, social support from supervisor and colleagues, and positive appreciation (which were expected to weaken the major hypothesized relationships), and time pressure, mental load, and involuntary task interruption (which were expected to strengthen the major hypothesized relationships). The analysis also included the possible effects of age and seniority. Controls based on craft methods, blood pressure and skin disorders were measured through observation. The effect of controls based on craft methods, and occupational strain were demonstrated. Effects were also shown of occupational strain on diastolic blood pressure and on problems in the locomotor system, and of positive appreciation on non-contact skin disorder.     

Investigating Unpaid Overtime Working among the Part‐time Workforce

This paper considers whether unpaid overtime working relates to contracted working hours (i.e. whether an employee works part‐time or full‐time) in Britain. It uses the authoritative 2004 British data set Workplace Employment Relations Survey to derive a sample of 4,530 workers, from 735 workplace establishments, who worked unpaid overtime. It tests hypotheses linking contracted working hours to unpaid overtime, and whether this link is moderated by gender, occupational group and the availability of flexible working arrangements. Part‐time workers were found to work significantly more unpaid overtime hours compared with their full‐time counterparts. Gender, occupation and flexible working practices moderated this relationship, where the extent to which part‐timers work more unpaid overtime than their full‐time counterparts was greater for men than for women, was greater for professional/managerial part‐time workers compared with other occupations, and was more evident in establishments less likely to offer flexible working arrangements. The findings raise concerns about the exploitation of part‐time workers.     

Psychophysiological stress reactions, trapezius muscle activity, and neck and shoulder pain among female cashiers before and after introduction of job rotation

The aim of this study was to evaluate the effects of the introduction of a job rotation model on supermarket cashiers, with respect to psychophysiological stress reactions, muscle activity of the trapezius muscle (which covers the upper back, the neck and the shoulder), and musculoskeletal symptoms in the neck and shoulders. Thirty-one female cashiers were investigated before and after job rotation was introduced. Before the reorganization the participants were only performing cash register work at the checkout counters. After the reorganization they shifted between cash register work and work in different departments in the supermarket. At follow-up the participants, all right-handed, had a significantly lower diastolic blood pressure, and surface electromyography (EMG) showed a significantly decreased muscle activity in the trapezius muscle on the left side. Musculoskeletal symptoms of the neck and shoulders were only partly changed, and there was no change in prevalence of musculoskeletal pain, which was around 70%. From questionnaires, but not from self-ratings during work, it was found that the introduction of job rotation had been experienced as positive in several regards, although the perceptions of stress and hurry were the same at follow-up.     

Psychophysiological stress reactions,trapezius muscle activity,and neck and shoulder pain among female cashiers before and after introduction of job rotation

The aim of this study was to evaluate the effects of the introduction of a job rotation model on supermarket cashiers, with respect to psychophysiological stress reactions, muscle activity of the trapezius muscle (which covers the upper back, the neck and the shoulder), and musculoskeletal symptoms in the neck and shoulders. Thirty-one female cashiers were investigated before and after job rotation was introduced. Before the reorganization the participants were only performing cash register work at the checkout counters. After the reorganization they shifted between cash register work and work in different departments in the supermarket. At follow-up the participants, all right-handed, had a significantly lower diastolic blood pressure, and surface electromyography (EMG) showed a significantly decreased muscle activity in the trapezius muscle on the left side. Musculoskeletal symptoms of the neck and shoulders were only partly changed, and there was no change in prevalence of musculoskeletal pain, which was around 70%. From questionnaires, but not from self-ratings during work, it was found that the introduction of job rotation had been experienced as positive in several regards, although the perceptions of stress and hurry were the same at follow-up.     

Relationship between job control, work pressure and strain: studies in the USA and in The Netherlands

The purpose of this study was to test a model of job control, work pressure and strain in two samples in the USA and in The Netherlands. According to the proposed model, work pressure has a mediating role between job control and worker strain. The present model specifies three types of job control: task or instrumental control, conceptual or resource control, and decision organization control. Task and resource control are assumed to reduce the stressor of work pressure which, in turn, is related to high strain. Organization control is assumed to be positively related to work pressure. The model was tested in two samples : one US sample of 273office employees and one Dutch sample of 958 employees in a variety of jobs. The same measure of job control was used in both samples. Resultspartially confirm the proposed model. As predicted by the proposed model, high task control was related to low work pressure, whereas high organization control was related to high work pressure. The effects of task control and organization control on strain were mediated by work pressure for the measure of anxiety in the US sample and for the measure of stress in the Dutch sample. However, the mediating effect of work pressure was not found for job satisfaction in both samples, for the measure of mood disturbances in the US sample and for the measure of sick days in the Dutch sample. The proposed model is only partially confirmed by the results. These results confirm the importance of differentiating between different dimensions of job control.     

Relationship between job control,work pressure and strain: Studies in the USA and in The Netherlands

The purpose of this study was to test a model of job control, work pressure and strain in two samples in the USA and in The Netherlands. According to the proposed model, work pressure has a mediating role between job control and worker strain. The present model specifies three types of job control: task or instrumental control, conceptual or resource control, and decision organization control. Task and resource control are assumed to reduce the stressor of work pressure which, in turn, is related to high strain. Organization control is assumed to be positively related to work pressure. The model was tested in two samples : one US sample of 273office employees and one Dutch sample of 958 employees in a variety of jobs. The same measure of job control was used in both samples. Resultspartially confirm the proposed model. As predicted by the proposed model, high task control was related to low work pressure, whereas high organization control was related to high work pressure. The effects of task control and organization control on strain were mediated by work pressure for the measure of anxiety in the US sample and for the measure of stress in the Dutch sample. However, the mediating effect of work pressure was not found for job satisfaction in both samples, for the measure of mood disturbances in the US sample and for the measure of sick days in the Dutch sample. The proposed model is only partially confirmed by the results. These results confirm the importance of differentiating between different dimensions of job control.     

Overtime usage in a job shop environment

Problems are encountered in a job shop which has a fixed capacity if the total work content of the jobs passing through the shop increases sufficiently. Even the use of effective priority dispatching rules and/or expediting does not adequately shorten the queues which develop if the total work content continually exceeds shop capacity. To avoid losing job orders because the orders are unduly delayed, the job shop might resort to overtime usage. This study examines the efficient and economic use of overtime to relieve the backlog problem and uses overtime as the basic criterion for evaluation of overtime usage. The study employs GPSS V programming language to simulate a hypothetical job shop. The shop is loaded to various proportions of its normal capacity and various levels of overtime are tested. Findings show that overtime should not be assigned indiscriminately but rather should be based on a shop's unique conditions of overtime cost, the priority rule being employed, and the level of capacity utilization. Marginal benefit-cost ratio curves are developed to determine whether overtime usage is economically reasonable. These curves may also be used to determine the maximum or limiting amount of overtime to use under specific shop conditions.     

Workload and morning salivary cortisol in women

Previous studies have shown a link between work-related stress and the morning level of the stress hormone cortisol. The level of cortisol in the circulation is regulated by the hypothalamic-pituitary-adrenocortical (HPA) axis, dysregulation of which plays an important role in a number of disorders including hypertension, immune deficiency and being overweight (the 'metabolic syndrome'). The aim of this study was to investigate the association between workload and morning cortisol in women. Saliva samples were obtained four times during the first 45 min after awakening (0, 15, 30 and 45 min) in the morning on a work-free day from more than 200 women in full-time work who were born in 1955 and representing a normal population of a small city in Sweden. The amount of paid and unpaid work was reported in a questionnaire. Significant positive correlations were found between the amount of overtime at work and each of the four measurements of morning salivary cortisol (varying from r = .29 to r = .38, p < .01). In addition, participants with excessive overtime (more than 10 h/week) had on average about twice as high ( p < .01) morning cortisol levels as women with moderate overtime (< 10 h/week) or normal working hours (35-40 h/week). The results are consistent with earlier findings and suggest that morning cortisol is a sensitive indicator of work overload in women. However, additional research is necessary in order to reveal the specific pathways linking work-related stress to elevated morning cortisol.     

Changes in mental well-being,blood pressure and total cholesterol levels during workplace reorganization: The impact of uncertainty

The aim of this study was to investigate the effects of uncertainty caused by large-scale workplace reorganization, on psychological well-being, blood pressure and total cholesterol levels. Employees (98 women and 86 men) were assessed four times, at approximately 6-monthly intervals, twice before and twice after reorganization. Self-reported psychological well-being was at its lowest level shortly prior to reorganization, as predicted. Greater self-reported uncertainty about one's own future occupational situation was associated with a bigger reduction in mental well-being before reorganization, as was role ambiguity after reorganization. Systolic blood pressure was elevated over initial levels just prior to reorganization, and shortly after reorganization, but at the final assessment was not significantly different from initial levels. A bigger increase in systolic blood pressure was seen in those reporting greater future job uncertainty before reorganization, and in those who started a new job or who reported greater role ambiguity after reorganization. Diastolic blood pressure was also significantly elevated over initial levels just before reorganization, but this effect became nonsignificant once changes in body mass index were statistically controlled. Total cholesterol also reached its highest level just prior to reorganization, but this effect was not significant. It is concluded that workplace reorganization caused significant increases in distress and in systolic blood pressure and that uncertainty contributed to these effects.     

Flexible Work and Turnover: an Empirical Investigation across Cultures

We explored the relationship between three bundles of flexible work arrangements (FWAs) and turnover for two of GLOBE's societal clusters, namely Anglo and Nordic. We collected data through a large‐scale international survey and found significant differences in the FWA–turnover relationship between the two clusters. Specifically, as unsocial hours (overtime, shift work, weekend work) and part‐time arrangements (part‐time and job‐sharing) increase in the Anglo cluster, so does turnover. Further, as schedule flexibility (telework, work from home and flexi‐time) increases in the Nordic cluster, turnover decreases. The results raise issues about the universal applicability of FWA policies and practices among nationally and internationally operating organizations.     

Determining overtime policies for a repair shop

Problems arise when a repair shop with a fixed capacity has to cope with fluctuations in the arrivals of failed assemblies. The effective use of priority scheduling rules and labor assignment rules will enable the repair shop to work efficiently but only to the extent of the repair capacity of the shop. Increasing the number of spares in stock to accommodate these short-term fluctuations would be costly in the long run. In order to maintain a certain level of service, the repair shop often needs to resort to overtime. This paper examines various overtime policies, namely, proactive and reactive overtime policies, under various failure distributions and budget constraints for spares. The findings show that reactive overtime policies generally perform better than proactive overtime policies under the conditions tested. Benefit-cost ratio curves are developed for these overtime policies which illustrate the stochastic interaction effects of the priority scheduling rule, spares budget, and failure arrival distribution.     

Work-home interference: How does it manifest itself from day to day?

Although work-home interference (WHI) refers to a process of negative interaction between the work and home domains, little attention has been paid to the actual processes involved in the within-person, day-to-day management of work and home. Therefore, this study investigated if, and how, a global report for the individual, of WHI (i.e., a general indicator of experienced WHI) is reflected in daily reports of WHI, in employees' daily activity patterns in the work and home domain, and in their daily health and well-being. Effort-Recovery theory (Meijman & Mulder, 1998) provided the theoretical basis for this study. Data were collected among 120 academic staff members (62% male) who completed a general questionnaire, addressing global WHI as well as demographical information, and who also participated in a 5-day daily diary study. WHI was measured using the 8-item WHI subscale of the Survey Work-home Interaction Nijmegen (SWING), with an adapted version being used for the diary studies. Results showed that global WHI: (1) was positively related to daily WHI; (2) was positively related to the time spent daily on overtime work in the evening; (3) was negatively related to the time spent daily on low-effort activities; and (4) was positively related to daily fatigue and sleep complaints. We conclude that Effort-Recovery theory seems promising for the study of WHI, and that diary studies are valuable, as these provide detailed insight into what global reports of WHI actually signify from day to day.     

Nutrient intake in day workers and shift workers

The 24-h dietary intake, nutritional status parameters and psychosomatic factors of two-shift, three-shift and day workers were compared. Estimations of the dietary intake (across a work cycle) were made by use of a nutrient database. No significant differences were found between the groups for a large number of nutritional variables: intake of energy; intake and percentage of energy from protein, fat, total carbohydrates and sucrose; intake of coffee; and intake and density of vitamins and minerals. Only minor differences were found between the groups with regard to the quantitative intake of alcohol and calcium, and with regard to the quality of the diet (percentage of energy from alcohol, density of calcium). The groups differed significantly with respect to attitude towards work hours (three-shift workers being most negative in their attitude) and sleep disturbances (shift workers being most negative). The three-shift workers were more evening-oriented and they had higher concentrations of glucose in their blood. It was concluded that work hours not related to nutritional intake—at least not when total amounts across time are considered. It was also concluded that work hours were not related to Body Mass Index or blood lipids: triglycerides, total cholesterol, LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol.     

Changes in mental well-being, blood pressure and total cholesterol levels during workplace reorganization: the impact of uncertainty

The aim of this study was to investigate the effects of uncertainty caused by large-scale workplace reorganization, on psychological well-being, blood pressure and total cholesterol levels. Employees (98 women and 86 men) were assessed four times, at approximately 6-monthly intervals, twice before and twice after reorganization. Self-reported psychological well-being was at its lowest level shortly prior to reorganization, as predicted. Greater self-reported uncertainty about one's own future occupational situation was associated with a bigger reduction in mental well-being before reorganization, as was role ambiguity after reorganization. Systolic blood pressure was elevated over initial levels just prior to reorganization, and shortly after reorganization, but at the final assessment was not significantly different from initial levels. A bigger increase in systolic blood pressure was seen in those reporting greater future job uncertainty before reorganization, and in those who started a new job or who reported greater role ambiguity after reorganization. Diastolic blood pressure was also significantly elevated over initial levels just before reorganization, but this effect became nonsignificant once changes in body mass index were statistically controlled. Total cholesterol also reached its highest level just prior to reorganization, but this effect was not significant. It is concluded that workplace reorganization caused significant increases in distress and in systolic blood pressure and that uncertainty contributed to these effects.     

Effort-reward imbalance,overcommitment and sleep in a working population

The relationship between workplace characteristics and nocturnal sleep in a working population was investigated. Data from 709 employees (mean age=39 years; 87% men) from two German companies were analysed at the entry of the longitudinal cohort study (overall accrual 73%). We investigated the association between the effort-reward imbalance model at work (Siegrist, ) and self-reported sleep quality and sleep disturbances, as assessed by the Jenkins Sleep Quality Index. Effort and overcommitment were found to be higher, and reward was lower in participants with lower (N=328) vs. higher sleep quality (N=381), as well as in participants with (N=217) vs. without (N=492) disturbed sleep (all ps<.001). In regression analyses, lower sleep quality (R ²=.33) and sleep disturbances (R ² _Nagelkerke=.33) were predicted by older age, female gender (only significant for sleep disturbances), shift-work, lower physical and mental health functioning, and higher overcommitment. Individuals were 1.7 times more likely to report disturbed sleep per standard deviation increase in overcommitment. Gender-stratified analyses revealed that higher overcommitment was associated with unfavourable sleep in men, while in women poor sleep was related to lower reward. The findings suggest that overcommitment at work interferes with restful sleep in men, while in women disturbed sleep may be associated with the amount of overcommitment and perceived job reward and sleep quality associated with the perceived reward.