Control at work: a generalized resource factor for the prevention of musculoskeletal symptoms?

During the last two decades two potent groups of predictors for work-related musculoskeletal problems have been identified: physical work load and poor psychosocial working conditions. However, little is known about their combined effects. In this study the buffering effect of control at work with respect to the negative effects of psychological demands and physical work load on musculoskeletal problems is examined. All study variables were sampled from 431 people working in geriatric nursing homes in Germany by means of questionnaires. Main effects and interactions were tested with multiple regression analysis. The results showed that control buffered the effects of high psychological demands, but not of high physical work load; the buffering effect of control was observed only when physical work load was low. The combined effects of demands and physical work load were over-additive. Thus, the power of different predictors for musculoskeletal symptoms depended on the level of other predictors. This suggests that the efficiency of certain strategies for the prevention of musculoskeletal problems is likely to depend on the level of risk factors, with different strategies being appropriate for different levels of risk.     

Editorial: Cognitive science,occupational stress and organizational health

A number of studies have shown that musculoskeletal symptoms are related to the physical and psychosocial work environments. Workers with musculoskeletal symptoms are often advised to cope by such measures as changing working technique, using lifting equipment and discussing health and environmental problems with supervisors and colleagues. Intervention studies at the individual level, however, have shown that such advice has limited effects in reducing the prevalence of musculoskeletal symptoms. The hypothesis for this study was that negative social and organizational factors may prevent workers from implementing such coping strategies. All 103 motor vehicle mechanics surveyed in 12 different garages responded to a questionnaire on coping with musculoskeletal symptoms and the psychosocial work environment. Positive and significant relationships were shown between how mechanics coped with their musculoskeletal symptoms and such psychosocial factors as work demands, social support, control, manager's involvement in health and safety work, and whether the garages had regular meetings between management and workers. Achieving positive results from preventive work through back schools and other ergonomic interventions seems to require that an organization with positive attitudes towards health and safety work be created before such interventions are implemented.     

The validity of the occupational stress indicator

This paper investigates the validity of four subscales of the Occupational Stress Inventory (OSI). Data derived from a sample of British managers are used to generate a multitrait-multimethod matrix. The results obtained suggest that three of the four OSI sales (job satisfaction, mental health, type A behaviour) show acceptable validity. The fourth scale (locus of control) needs further development. Further analysis, using multiple regression procedures, was conducted to explore the validity of the theoretical ideas underlying the OSI. The results reveal that both sources of pressure at work and type A behaviour are linked to mental health and job satisfaction.     

A re-analysis of the occupational stress indicator

Abstract

This paper investigates the reliability of the Occupational Stress Indicator (OSI). Data from a sample of university staff, drawn from all areas of an urban university, are used to reassess the apparently low reliabilities of many of the OSI subscales reported by Cooper et al. (1988). In addition, factor analysis results are reported for the first time for the sources of pressure data. The reliability data reported here, while higher reliabilities than originally obtained, remain unacceptably low. A lack of stability in the device as it is currently formulated seems apparent. The paper also presents for the first time a detailed analysis of the sources of pressure scale, indicating a solution different from that proposed by Cooper et al. (1988). Certain areas of the OSI clearly need refinement; the inclusion of locus of control and type A behaviour as personality variables in particular is called into question. Observations regarding the particular strengths and weaknesses of this device, and suggestions for future refinements, are offered.     

A re-analysis of the occupational stress indicator

This paper investigates the reliability of the Occupational Stress Indicator (OSI). Data from a sample of university staff, drawn from all areas of an urban university, are used to reassess the apparently low reliabilities of many of the OSI subscales reported by Cooper et al. (1988). In addition, factor analysis results are reported for the first time for the sources of pressure data. The reliability data reported here, while higher reliabilities than originally obtained, remain unacceptably low. A lack of stability in the device as it is currently formulated seems apparent. The paper also presents for the first time a detailed analysis of the sources of pressure scale, indicating a solution different from that proposed by Cooper et al. (1988). Certain areas of the OSI clearly need refinement; the inclusion of locus of control and type A behaviour as personality variables in particular is called into question. Observations regarding the particular strengths and weaknesses of this device, and suggestions for future refinements, are offered.     

The impact of learning opportunities and decision authority on occupational health

In an investigation of 418 employees in the Norwegian Postal Service, employees with high learning opportunities and high decision authority were found to be better off on psychological functioning, health and organizational outcome variables than employees with low scores on these variables. Decision authority and learning opportunities had specific and independent impact on subjective health, psychological functioning, coping style and organizational outcome variables. There were, however, also interaction effects between demands, learning opportunities, and decision authority on subjective health. Learning opportunities and decision authority were operationalized with a questionnaire, supplemented with questions on the opportunities to learn skills beyond the present job situation. It is suggested that this is a particularly important dimension for coping with the present day rapid changes in working life, where the objective for many workers will be to broaden their repertoire and competence to increase their flexibility in the labour market.     

The impact of learning opportunities and decision authority on occupational health

In an investigation of 418 employees in the Norwegian Postal Service, employees with high learning opportunities and high decision authority were found to be better off on psychological functioning, health and organizational outcome variables than employees with low scores on these variables. Decision authority and learning opportunities had specific and independent impact on subjective health, psychological functioning, coping style and organizational outcome variables. There were, however, also interaction effects between demands, learning opportunities, and decision authority on subjective health. Learning opportunities and decision authority were operationalized with a questionnaire, supplemented with questions on the opportunities to learn skills beyond the present job situation. It is suggested that this is a particularly important dimension for coping with the present day rapid changes in working life, where the objective for many workers will be to broaden their repertoire and competence to increase their flexibility in the labour market.     

Cortisol on Sunday as indicator of recovery from work: Prediction by observer ratings of job demands and control

Several considerations guided the research reported in this paper. First, recovery is pivotal for preventing stressful experiences from inducing long-term consequences. Second, cortisol levels under relaxed conditions constitute a good baseline measure. Third, there are many calls to avoid common method problems. Therefore, the Job Demands–Control (JDS) model, one of the most prominent models in occupational stress, should be tested by a combination of observation, self-report, and physiological data in terms of predicting recovery-related variables. In a sample of 53 Swiss employees, we assessed the JDS variables, demands and control, by systematic observation, fatigue at the end of work as an indicator of short-term recovery by questionnaire, and delayed recovery by baseline levels of cortisol on a Sunday under relaxing conditions. In line with expectations, regression analyses showed an impact of job demands and control on Sunday cortisol levels, and this effect was fully mediated by after work fatigue. Contrary to expectations, there was no significant interaction between job demands and control. Demonstrating that job demands and control predict after-work fatigue as well as a delayed physiological marker of recovery, these findings suggest that high after-work fatigue may entail costs to the individual’s physiological systems.     

How the psychosocial work environment of motor vehicle mechanics may influence coping with musculoskeletal symptoms

A number of studies have shown that musculoskeletal symptoms are related to the physical and psychosocial work environments. Workers with musculoskeletal symptoms are often advised to cope by such measures as changing working technique, using lifting equipment and discussing health and environmental problems with supervisors and colleagues. Intervention studies at the individual level, however, have shown that such advice has limited effects in reducing the prevalence of musculoskeletal symptoms. The hypothesis for this study was that negative social and organizational factors may prevent workers from implementing such coping strategies. All 103 motor vehicle mechanics surveyed in 12 different garages responded to a questionnaire on coping with musculoskeletal symptoms and the psychosocial work environment. Positive and significant relationships were shown between how mechanics coped with their musculoskeletal symptoms and such psychosocial factors as work demands, social support, control, manager's involvement in health and safety work, and whether the garages had regular meetings between management and workers. Achieving positive results from preventive work through back schools and other ergonomic interventions seems to require that an organization with positive attitudes towards health and safety work be created before such interventions are implemented.     

The effectiveness of input control based on aggregate versus bottleneck work loads

This study compares input control based on aggregate shop loads with that based on bottleneck resource loads. Two appropriate release mechanisms are developed and compared in flow and job shops that have various levels of a bottleneck constraint. Simulation results show that both the level of bottleneck and the flow pattern influence the effectiveness of the strategies. Release based on aggregate loads works well when shop loads are balanced or when there is a bottleneck but the flow is highly structured, as in a flow shop. Release based on bottleneck loads works best when flow patterns are less structured, as in a job shop.     

The impact of VDU use and psychosocial factors at work on musculoskeletal shoulder symptoms among white-collar workers

This investigation of white-collar workers ( n = 201) in Swedish industrial environments focused on an empirical examination of the relationships between work with visual display units (VDUs), psychosocial factors (skill discretion, appraised work load, job satisfaction), physical work load and musculoskeletal shoulder symptoms. This cross-sectional study was based upon questionnaire surveys carried out at industrial companies. The prevalence of shoulder symptoms during the previous year was 39%. Nearly one-half of the participants reported that they used a VDU for at least 4 h/day ('high VDU use'). High VDU use was related to increased Prevalence Odds Ratio (POR) for shoulder symptoms. After adjustment for physical work load, significant PORs were found in groups with high VDU use in combination with low job satisfaction (POR = 4.8) or high appraised work load (POR = 3.5), compared to groups with low VDU use in combination with high job satisfaction or low work load (reference groups).     

Testing the Vitamin Model of job stress in Dutch health care workers

Three central hypotheses of Warr's Vitamin Model concerning the relationship between job characteristics and well-being and health outcomes were tested: (1) differential effects of job characteristics on the various well-being and health outcomes; (2) predominance of curvilinear associations; and (3) moderate influence of negative and positive affectivity on these relationships. The study participants were 162 employees from a health care organization (aged 19–54 years, 95% women) who completed questionnaires on job demands and job autonomy, as well as on the outcome variables depression, anxiety, job satisfaction, and health complaints. In addition, data on short-term sickness absence were collected. A higher level of job demands was significantly associated with a lower level of well-being and self-reported health. Job autonomy showed weaker relationships with the outcome variables. The effects of job demands were still large after controlling for negative and positive affectivity, while the effects of job autonomy in most cases became non-significant. The predicted curvilinear relationship between job characteristics and outcome variables did not have an additional value over a linear model in predicting the data. It is concluded that the present data from a homogeneous sample of mostly female nurses support Warr's Vitamin Model to a limited extent.     

Testing the Vitamin Model of job stress in Dutch health care workers

Three central hypotheses of Warr's Vitamin Model concerning the relationship between job characteristics and well-being and health outcomes were tested: (1) differential effects of job characteristics on the various well-being and health outcomes; (2) predominance of curvilinear associations; and (3) moderate influence of negative and positive affectivity on these relationships. The study participants were 162 employees from a health care organization (aged 19-54 years, 95% women) who completed questionnaires on job demands and job autonomy, as well as on the outcome variables depression, anxiety, job satisfaction, and health complaints. In addition, data on short-term sickness absence were collected. A higher level of job demands was significantly associated with a lower level of well-being and self-reported health. Job autonomy showed weaker relationships with the outcome variables. The effects of job demands were still large after controlling for negative and positive affectivity, while the effects of job autonomy in most cases became non-significant. The predicted curvilinear relationship between job characteristics and outcome variables did not have an additional value over a linear model in predicting the data. It is concluded that the present data from a homogeneous sample of mostly female nurses support Warr's Vitamin Model to a limited extent.     

The impact of sense of coherence and high-demand/low-control job environment on self-reported health,burnout and psychophysiological stress indicators

Sense of Coherence (SOC) is a new concept belonging to a salutogenic paradigm, proposing to explain health as contrasted to disease, a pathogenic paradigm. The Job Demand-Control (JDC) model of job stress suggests that the combination of high job demands and low job control, defined as job strain, is strongly associated with adverse health consequences. The aim of this study was to evaluate the relationship between SOC and the JDC model in assessment of negative job effects within three pathogenically defined contexts: self-reported health, burnout and psychophysiological stress indicators, assessing the explanatory value of SOC for such variables. The study was conducted with 103 employees of social-welfare and social-insurance agencies in Sweden. A questionnaire related to job conditions, health and burnout was administered, and blood samples were collected and analysed for serum concentrations of cortisol, prolactin and immunoglobulin G. Multiple-regression models were calculated including variables from all three contexts. In the analyses, a distinction was made between emotional job strain and quantitative job strain. The SOC interacted with emotional job strain, but the interaction also increased the independent effect of emotional job strain. The independent effect of SOC disappeared in most models when interaction was included. It is concluded that studies of job strain-effects according to the JDC model should include the SOC as an interaction factor.     

The impact of shiftwork on personnel at a nuclear power plant: An exploratory survey study

Shiftwork may constitute an additional risk factor in high-hazard industries where system failure could exact heavy human, environmental and economic costs. This exploratory survey study examined the impact of shiftwork upon nuclear power plant workers' perceived health, sleep, and social problem, as well as levels of alertness. Overall, the night shik proved to be the most problematic in ternis of decreases in alertness, sleep duration and quality, and disruptions to health, social and family life. The permanent shift preferences of the shiftworkers were also explored to establish the practicability of introducing a theoretically safer permanent mght shdt at such a facility. Importantly, the small proportion of the sample who showed a preference for a pemianent night shift was insufficient to provide operational cover. Although these shtftworkers reported experiencing less disruption on the night shift than those who would choose to work a permanent day shift, their preference appeared to be based upon a greater esprit de corps on this shift rather than on any predisposing individual characteristics. These results have practical implications for work scheduling in high-hazard industries.

The present study investigates the dimensional structure of the psychosocial work environment as assessed by Karasek's job characteristics scales and a set of factorial scales derived from the Dictionary of Occupational Titles (DOT) observers' ratings of occupational characteristics for census occupations. Scale scores on the Karasek and DOT were linked to information on occupation from the Epidemiologc Catchment Area (ECA) study sample. Scale intercorreladons and factor analysis were performed on those ECA subjects who reported ever having a full-time job (n=11,789). DOT'sS Substantive Complexity scale was positively correlated with Karasek's Skill Discretion and Decision Authority scales, and DOT's Physical Demands and Hazards scale was positively correlated with Karasek's Physical Demands scale. In addition, the DOT system compared to the Karasek system seems to assess psychosocial work domains less characteristic of traditional industrial jobs (interpersonal stress, expressive work). The content validity of the Karasek scales might be increased with the assessment of these domains. Giving support to Karasek's Demand/Control Model, the factor structure of the psychosocial work enviromnent in the probability sample of five US metropolitan populations yielded two major dimensions: Control, and Physical Demands.     

The Japanese version of the Effort-Reward Imbalance Questionnaire: A study in dental technicians

To test the psychometric properties and criterion validity of the Japanese version of the EffortReward Imbalance (ERI) Questionnaire (Siegrist, 1996), a survey was conducted among 105 male dental technicians. The Japanese version of the questionnaire was developed through a backtranslation process. Internal consistency and factorial structure were tested and the criterion validity with respect to musculoskeletal symptoms was estimated with the help of a correlation matrix and logistic regression analysis. In psychometric terms, the factorial structure of the scales measuring the components of the theoretical concept was replicated satisfactorily, and internal consistencies of the scales measuring the extrinsic and intrinsic components of the model were appropriate. Significant associations between components of the ERI and musculoskeletal symptoms were found. Logistic regression analysis revealed a significantly elevated risk of musculoskeletal symptoms in participants scoring high on the scale measuring the model's intrinsic component, 'overcommitment'. This study indicates that, at least for the occupational group under study, the Japanese version of the ERI Questionnaire is a feasible and psychometrically well justified new measure for assessing psychosocial stress at work with relevance to health.     

The Danish psychosocial work environment and symptoms of stress: The main,mediating and moderating role of sense of coherence

The aim of this cross-sectional study was to explore the main, mediating and moderating role of sense of coherence (SOC) on stress symptoms and on the association between perceived psychosocial work environment and stress symptoms. The sample includes 2053 Danish employees from 52 workplaces. Hierarchical regression models were applied for each measure of stress. The results strongly supported the presence of a main effect for SOC. People with high levels of SOC experienced fewer stress symptoms. A mediating effect of SOC was also supported. Thus, SOC in part explained the association between work environment and stress symptoms. In addition, some support for a moderating effect of SOC was found, suggesting that people with higher SOC coped more efficiently with work environmental strain that people with lower SOC. Taken together the regression models explained 11–32% of the variance in stress symptoms. The results suggest that measures of individual factors such as SOC should be included in analyses of the effects of work environmental factors on stress and well-being.     

The impact of sense of coherence and high-demand/low-control job environment on self-reported health, burnout and psychophysiological stress indicators

Sense of Coherence (SOC) is a new concept belonging to a salutogenic paradigm, proposing to explain health as contrasted to disease, a pathogenic paradigm. The Job Demand-Control (JDC) model of job stress suggests that the combination of high job demands and low job control, defined as job strain, is strongly associated with adverse health consequences. The aim of this study was to evaluate the relationship between SOC and the JDC model in assessment of negative job effects within three pathogenically defined contexts: self-reported health, burnout and psychophysiological stress indicators, assessing the explanatory value of SOC for such variables. The study was conducted with 103 employees of social-welfare and social-insurance agencies in Sweden. A questionnaire related to job conditions, health and burnout was administered, and blood samples were collected and analysed for serum concentrations of cortisol, prolactin and immunoglobulin G. Multiple-regression models were calculated including variables from all three contexts. In the analyses, a distinction was made between emotional job strain and quantitative job strain. The SOC interacted with emotional job strain, but the interaction also increased the independent effect of emotional job strain. The independent effect of SOC disappeared in most models when interaction was included. It is concluded that studies of job strain-effects according to the JDC model should include the SOC as an interaction factor.     

The Japanese version of the Effort-Reward Imbalance Questionnaire: a study in dental technicians

To test the psychometric properties and criterion validity of the Japanese version of the EffortReward Imbalance (ERI) Questionnaire (Siegrist, 1996), a survey was conducted among 105 male dental technicians. The Japanese version of the questionnaire was developed through a backtranslation process. Internal consistency and factorial structure were tested and the criterion validity with respect to musculoskeletal symptoms was estimated with the help of a correlation matrix and logistic regression analysis. In psychometric terms, the factorial structure of the scales measuring the components of the theoretical concept was replicated satisfactorily, and internal consistencies of the scales measuring the extrinsic and intrinsic components of the model were appropriate. Significant associations between components of the ERI and musculoskeletal symptoms were found. Logistic regression analysis revealed a significantly elevated risk of musculoskeletal symptoms in participants scoring high on the scale measuring the model's intrinsic component, 'overcommitment'. This study indicates that, at least for the occupational group under study, the Japanese version of the ERI Questionnaire is a feasible and psychometrically well justified new measure for assessing psychosocial stress at work with relevance to health.     

The Danish psychosocial work environment and symptoms of stress: the main, mediating and moderating role of sense of coherence

The aim of this cross-sectional study was to explore the main, mediating and moderating role of sense of coherence (SOC) on stress symptoms and on the association between perceived psychosocial work environment and stress symptoms. The sample includes 2053 Danish employees from 52 workplaces. Hierarchical regression models were applied for each measure of stress. The results strongly supported the presence of a main effect for SOC. People with high levels of SOC experienced fewer stress symptoms. A mediating effect of SOC was also supported. Thus, SOC in part explained the association between work environment and stress symptoms. In addition, some support for a moderating effect of SOC was found, suggesting that people with higher SOC coped more efficiently with work environmental strain that people with lower SOC. Taken together the regression models explained 11-32% of the variance in stress symptoms. The results suggest that measures of individual factors such as SOC should be included in analyses of the effects of work environmental factors on stress and well-being.