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.     

Job design and levels of physical and mental strain among Australian prison officers

Over the past 15 years much has been made of the moderating influence of job discretion and support in occupations that are perceived to be high in demands. Such an effect seems to be most prevalent when subject populations are large and heterogeneous. One aim of this study was to examine the influence of subjective perceptions of these variables on strain reactions among a group of relatively homogeneous workers such as, in the present study, prison officers (n = 274). A second aim was to extend previous research and examine the joint influence of negative affectivity and perceptions of demands, discretion, and support on mental and physical well-being. It was hypothesized that those high in negative affect would be particularly strained by jobs perceived as being demanding. The hypothesized relationship between job demands, discretion and support were found to be weak and at times inconsistent. Social support, in particular, was found to have both positive and negative consequences for different aspects of well-being. Those high in negative affect were in general found to suffer lower mental well-being. More importantly, the interactive effect of negative affectivity and job demands was found to significantly predict the majority of the dependent variables used in this study. The valences of these relationships were inconsistent and are interpreted in light of Warr's (1987) vitamin model of stress.

There are several conclusions that can be drawn from the present study. Negative affectivity appears to have a truly interactive effect with job components, job demands in particular, to influence a range of variables relating to physical and mental health as well a job-related attitudes. The nature of these effects, however, suggests a dissociation in the ways that different independent variables influence a range of indices of well-being and affect. This result requires further investigation since there are important theoretical implications which will follow if the data are replicable.

In order to examine such complex effects, in addition to the need for more longitudinal studies, it is also important that standardized measures of job components are developed so that levels of stress exposure can be equated and their impact assessed across organizational settings.

Finally, the data reported in this study suggest that some effective stress management may be undertaken by adopting selection strategies which take into consideration individual characteristics. In view of the fact that individual stress management programmes are of unproven benefit (Murphy 1986, 1988) such an approach is recommended especially for those organizations which are highly constrained in the services that must be performed.     

Is there support for curvilinear relationships between psychosocial work characteristics and mental well-being? Cross-sectional and long-term data from the Whitehall II study

This study aimed to test whether curvilinearity would add explanatory power to the long-term relationships between job characteristics and mental well-being. The study was based on cross-sectional and longitudinal data from phases 3 and 5 of the Whitehall II sample (N=4154 for job satisfaction and 6000 for context-free mental well-being, mean follow-up 5.8 years). The curvilinear components of the job characteristics were introduced after controlling for the baseline outcome measure, demographic factors, and the linear measures of the job characteristics. The cross-sectional analyses showed only a curvilinear association with the expected U-shape between job demands and context-free mental well-being. The longitudinal analyses showed no curvilinear relationships between the job characteristics and context-free mental well-being. While small non-linear relationships were found between social support and decision latitude and job-related mental well-being, the shape of these relationships was the reverse of that expected. Post hoc analyses revealed that only the positive segment of the relationship between decision latitude and job satisfaction was significant, while both segments of the relationship between social support and job satisfaction were significant. The findings from this study, based on a large sample with high variety in working conditions, provide little support for the assumption of curvilinearity in the long-term relationship between psychosocial working conditions and mental well-being. This has practical implications, as if associations are linear this would indicate that it would be reasonable to take a population (rather than individually targeted) approach to stress management interventions.     

Work-related stress,coping resources,and heavy drinking in the restaurant business

Abstract

This study aimed to test whether curvilinearity would add explanatory power to the long-term relationships between job characteristics and mental well-being. The study was based on cross-sectional and longitudinal data from phases 3 and 5 of the Whitehall II sample (N=4154 for job satisfaction and 6000 for context-free mental well-being, mean follow-up 5.8 years). The curvilinear components of the job characteristics were introduced after controlling for the baseline outcome measure, demographic factors, and the linear measures of the job characteristics. The cross-sectional analyses showed only a curvilinear association with the expected U-shape between job demands and context-free mental well-being. The longitudinal analyses showed no curvilinear relationships between the job characteristics and context-free mental well-being. While small non-linear relationships were found between social support and decision latitude and job-related mental well-being, the shape of these relationships was the reverse of that expected. Post hoc analyses revealed that only the positive segment of the relationship between decision latitude and job satisfaction was significant, while both segments of the relationship between social support and job satisfaction were significant. The findings from this study, based on a large sample with high variety in working conditions, provide little support for the assumption of curvilinearity in the long-term relationship between psychosocial working conditions and mental well-being. This has practical implications, as if associations are linear this would indicate that it would be reasonable to take a population (rather than individually targeted) approach to stress management interventions.     

Job design and levels of physical and mental strain among Australian prison officers

Abstract

Over the past 15 years much has been made of the moderating influence of job discretion and support in occupations that are perceived to be high in demands. Such an effect seems to be most prevalent when subject populations are large and heterogeneous. One aim of this study was to examine the influence of subjective perceptions of these variables on strain reactions among a group of relatively homogeneous workers such as, in the present study, prison officers (n = 274). A second aim was to extend previous research and examine the joint influence of negative affectivity and perceptions of demands, discretion, and support on mental and physical well-being. It was hypothesized that those high in negative affect would be particularly strained by jobs perceived as being demanding. The hypothesized relationship between job demands, discretion and support were found to be weak and at times inconsistent. Social support, in particular, was found to have both positive and negative consequences for different aspects of well-being. Those high in negative affect were in general found to suffer lower mental well-being. More importantly, the interactive effect of negative affectivity and job demands was found to significantly predict the majority of the dependent variables used in this study. The valences of these relationships were inconsistent and are interpreted in light of Warr's (1987) vitamin model of stress.

There are several conclusions that can be drawn from the present study. Negative affectivity appears to have a truly interactive effect with job components, job demands in particular, to influence a range of variables relating to physical and mental health as well a job-related attitudes. The nature of these effects, however, suggests a dissociation in the ways that different independent variables influence a range of indices of well-being and affect. This result requires further investigation since there are important theoretical implications which will follow if the data are replicable.

In order to examine such complex effects, in addition to the need for more longitudinal studies, it is also important that standardized measures of job components are developed so that levels of stress exposure can be equated and their impact assessed across organizational settings.

Finally, the data reported in this study suggest that some effective stress management may be undertaken by adopting selection strategies which take into consideration individual characteristics. In view of the fact that individual stress management programmes are of unproven benefit (Murphy 1986, 1988) such an approach is recommended especially for those organizations which are highly constrained in the services that must be performed.     

Testing the demand-control-support model among health-care professionals: A structural equation model

This paper reports a further empirical validation of the Demand-Control-Support Model (DCS model), which was developed by Johnson and colleagues (1988, 1989). Data were collected from a heterogeneous group of health-care professionals (nurses and nurses' aides; n = 249). Three major refinements were made to the validation of the DCS Model. First, all relationships in the model were estimated simultaneously by means of covariance structure modelling (LISREL 8). Second, the control dimension was refined substantially, using a psychometrically more sound assessment of the workers' autonomy. Third, the model was applied to the work of health-care professionals. The data did not confirm the assumption that both job strain and motivation are multiplicative functions of job demands, autonomy and social support. First, the results suggested that high levels of autonomy attenuate the increase of emotional exhaustion due to job demands. These results partially supported Karasek's Job Demand-Control Model (Karasek 1979). Second, high levels of social support proved to attenuate the increase of emotional exhaustion due to autonomy. Finally, the main effect of autonomy on job challenge implied that an increase in autonomy is accompanied by an increase in job challenge (and, consequently, job involvement). In addition, low job demands and a high amount of work-related support seem to reduce feelings of exhaustion and, consequently, health complaints.     

Testing the demand-control-support model among health-care professionals: A structural equation model

Abstract

This paper reports a further empirical validation of the Demand-Control-Support Model (DCS model), which was developed by Johnson and colleagues (1988, 1989). Data were collected from a heterogeneous group of health-care professionals (nurses and nurses' aides; n = 249). Three major refinements were made to the validation of the DCS Model. First, all relationships in the model were estimated simultaneously by means of covariance structure modelling (LISREL 8). Second, the control dimension was refined substantially, using a psychometrically more sound assessment of the workers' autonomy. Third, the model was applied to the work of health-care professionals. The data did not confirm the assumption that both job strain and motivation are multiplicative functions of job demands, autonomy and social support. First, the results suggested that high levels of autonomy attenuate the increase of emotional exhaustion due to job demands. These results partially supported Karasek's Job Demand-Control Model (Karasek 1979). Second, high levels of social support proved to attenuate the increase of emotional exhaustion due to autonomy. Finally, the main effect of autonomy on job challenge implied that an increase in autonomy is accompanied by an increase in job challenge (and, consequently, job involvement). In addition, low job demands and a high amount of work-related support seem to reduce feelings of exhaustion and, consequently, health complaints.     

The moderating role of personality characteristics on the relationship between job insecurity and strain

The experience of job insecurity has been linked to several different outcomes, such as negative attitudes towards work and the organization, turnover intention, as well as health complaints. However, since the strength of these effects have been found to vary across studies, it is vital to identify factors that could influence the relationships. The present study examines the moderating role of three personality characteristics (negative affectivity, positive affectivity, and external locus of control) on the relation between job insecurity and outcomes (mental health complaints, job dissatisfaction, and job-induced tension). Data from 400 nurses at a Swedish acute care hospital (response rate 71%; 91% women, aged 20-68 years) showed that both job insecurity and personality were related to strain. Also, the data indicated some buffering effect of personality. Despite the gender bias of the sample, the study provides additional support for the notion that job insecurity affects strain even after controlling for individual characteristics. The study also expands the literature on job insecurity by pointing out the influence of personality characteristics on the relationship between stressors and strain.     

Warr's scale of job-related affective well-being: A longitudinal examination of its structure and relationships with work characteristics

The aims of this 3-year follow-up study among Finnish managers (n=615) were first, to test the theoretically-based structure of the job-related affective well-being scale (Warr, 1990b), and second, to examine the linear and curvilinear longitudinal associations between work characteristics and job-related affective well-being. Confirmatory factor analysis showed that the hypothesized four-factor model best described the structure of the job-related affective well-being scale; that is, the scale included four interrelated factors of job-related anxiety, comfort, depression, and enthusiasm at both measurement times. Structural equation modelling showed that high feelings of comfort at work were longitudinally associated with a positive perception of the supportiveness of the organizational climate, after controlling for sense of coherence. Conversely, the work characteristics included in this study (job control and supportive organizational climate) did not serve as antecedents of job-related affective well-being during the follow-up. In addition, there were no cross-sectional or longitudinal curvilinear associations between work characteristics and job-related affective well-being: associations were found to be linear. We conclude that (a) Warr's scale of job-related affective well-being is best conceptualized as consisting of four interrelated dimensions whose factor structure is (b) highly stable across a 3-year time interval.     

The relationships between work characteristics and mental health: examining normal,reversed and reciprocal relationships in a 4-wave study

This longitudinal study examined the causal relationships between job demands, job control and supervisor support on the one hand and mental health on the other. Whereas we assumed that work characteristics affect mental health, we also examined reversed causal relationships (mental health influences work characteristics). Further, the topic of the appropriate time lag for testing causal relationships was addressed. Our hypotheses were tested in a 4-wave study among a heterogeneous sample of 668 Dutch employees using structural equation modelling. The results provide evidence for reciprocal causal relationships between the work characteristics and mental health, although the effects of work characteristics on well-being were causally predominant. The best model fit was found for a 1-year time lag. Compared to earlier—predominantly cross-sectional—results, the present study presents a stronger case for the effects of work characteristics on the development of strain. The results also emphasize the need for a dynamic view of the relationship between work and health; the one-directional viewpoint in many work stress models does not seem to fully capture the relations between work characteristics and well-being.     

Exploring work- and organization-based resources as moderators between work-family conflict, well-being, and job attitudes

In modern Western life it is difficult to avoid work-family conflict. Therefore the resources that might reduce its negative outcomes on well-being and job attitudes come into focus. Our study contributes to the work-family conflict literature by exploring the indirect (moderator) and direct role of three work- and organization-related resources, i.e., job control, family supportive climate, organization-based self-esteem (OBSE), in the work-to-family conflict and well-being/job attitude relationship. Theoretically, the study tested the recently developed Job Demands-Resources (JD-R) model in the Scandinavian context. Data for the study were gathered from three differing Finnish organizations (health care district, ICT company, Cardboard mill; n=1252). In line with the predictions of the JD-R model, job demands (time- and strain-based work-to-family conflict) were more robustly associated with strain-based outcomes (physical symptoms), whereas job resources (job control, family supportive climate, OBSE) were more strongly linked to motivational-based outcomes (job satisfaction, organizational commitment). Both job control and family supportive climate moderated the relationships studied; high job control and family supportive climate buffered against the aversive effects of work-to-family conflict on well-being and job attitudes. These indirect effects also varied in relation to the independent, moderator, and dependent variables. However, OBSE did not operate as a buffering factor, although it showed significant direct effects. From a practical viewpoint, our findings suggest that job control and family supportive climate are resources that help employees to reduce the negative effects related to work-family conflict.     

Exploring work- and organization-based resources as moderators between work–family conflict,well-being,and job attitudes

Abstract

In modern Western life it is difficult to avoid work–family conflict. Therefore the resources that might reduce its negative outcomes on well-being and job attitudes come into focus. Our study contributes to the work–family conflict literature by exploring the indirect (moderator) and direct role of three work- and organization-related resources, i.e., job control, family supportive climate, organization-based self-esteem (OBSE), in the work-to-family conflict and well-being/job attitude relationship. Theoretically, the study tested the recently developed Job Demands–Resources (JD-R) model in the Scandinavian context. Data for the study were gathered from three differing Finnish organizations (health care district, ICT company, Cardboard mill; n=1252). In line with the predictions of the JD-R model, job demands (time- and strain-based work-to-family conflict) were more robustly associated with strain-based outcomes (physical symptoms), whereas job resources (job control, family supportive climate, OBSE) were more strongly linked to motivational-based outcomes (job satisfaction, organizational commitment). Both job control and family supportive climate moderated the relationships studied; high job control and family supportive climate buffered against the aversive effects of work-to-family conflict on well-being and job attitudes. These indirect effects also varied in relation to the independent, moderator, and dependent variables. However, OBSE did not operate as a buffering factor, although it showed significant direct effects. From a practical viewpoint, our findings suggest that job control and family supportive climate are resources that help employees to reduce the negative effects related to work–family conflict.     

Longitudinal influences of managerial support on employee well-being

A three-wave longitudinal survey of managers working for a food retailer (n = 148) assessed both job characteristics and individual well-being during a period of organizational restructuring. Repeated measures analysis of variance revealed significant changes in both job characteristics and well-being across the three surveys. In addition, longitudinal structural equation models were developed to model the relationships between job characteristics and two indices of strain (job satisfaction and mental health) over time, including the assessment of the relative fit of competing causal process models. After controlling for the temporal stability of all variables, both types of strain were predicted by a combination of prior strain, prior job characteristics and current job characteristics. More specifically, managerial support was found to influence job satisfaction both directly and through perceptions of role ambiguity and control. Mental health was consistently predicted by low current and prior work demands, and in addition was associated with high managerial support. These results suggest that interventions to enhance employee well-being might usefully focus on increasing managerial support. Recommendations for research intending to examine the direction of causal associations between job characteristics and strain are made.     

The relationships between work characteristics and mental health: examining normal, reversed and reciprocal relationships in a 4-wave study

This longitudinal study examined the causal relationships between job demands, job control and supervisor support on the one hand and mental health on the other. Whereas we assumed that work characteristics affect mental health, we also examined reversed causal relationships (mental health influences work characteristics). Further, the topic of the appropriate time lag for testing causal relationships was addressed. Our hypotheses were tested in a 4-wave study among a heterogeneous sample of 668 Dutch employees using structural equation modelling. The results provide evidence for reciprocal causal relationships between the work characteristics and mental health, although the effects of work characteristics on well-being were causally predominant. The best model fit was found for a 1-year time lag. Compared to earlier—predominantly cross-sectional—results, the present study presents a stronger case for the effects of work characteristics on the development of strain. The results also emphasize the need for a dynamic view of the relationship between work and health; the one-directional viewpoint in many work stress models does not seem to fully capture the relations between work characteristics and well-being.     

The effects of new dimensions of psychological job demands and job control on active learning and occupational health

Recent changes in job content may have led to changes in job demands and control, and earlier operationalizations of the demand concept may be too general (MT). The aim of this paper is to show how new dimensions of psychological job demands are related to two sets of outcome variables, employee health and active learning, and how these relationships are modified or interact with social support and types of job control. The study was carried out as a survey among employees of 13 electric companies in Norway, N=2435. Lisrel was used to assess the fit of the proposed models. Compared to the traditional demands control model, an extended version used in this study increased the explained variance on an average by 4% on various occupational health variables. It was found that various dimensions of demands were differentially related to the outcome variables. Skill discretion uniformly reduced the effect of the demands: for groups low in skill discretion there was a stronger relationship between demands and outcomes than for groups high in skill discretion. The interaction pattern for the remaining control and support variables was however more complicated and warrants further study. The practical implications are that employers should carefully consider the quality of work. Special attention should be given to the quantitative demands of the jobs, since there seems to be few moderators for the relationship between those demands and job stress and subjective health complaints.     

The effects of new dimensions of psychological job demands and job control on active learning and occupational health

Abstract

Recent changes in job content may have led to changes in job demands and control, and earlier operationalizations of the demand concept may be too general (MT). The aim of this paper is to show how new dimensions of psychological job demands are related to two sets of outcome variables, employee health and active learning, and how these relationships are modified or interact with social support and types of job control. The study was carried out as a survey among employees of 13 electric companies in Norway, N=2435. Lisrel was used to assess the fit of the proposed models. Compared to the traditional demands control model, an extended version used in this study increased the explained variance on an average by 4% on various occupational health variables. It was found that various dimensions of demands were differentially related to the outcome variables. Skill discretion uniformly reduced the effect of the demands: for groups low in skill discretion there was a stronger relationship between demands and outcomes than for groups high in skill discretion. The interaction pattern for the remaining control and support variables was however more complicated and warrants further study. The practical implications are that employers should carefully consider the quality of work. Special attention should be given to the quantitative demands of the jobs, since there seems to be few moderators for the relationship between those demands and job stress and subjective health complaints.     

The Job Demands-Resources Model in emergency service volunteers: Examining the mediating roles of exhaustion,work engagement and organizational connectedness

Using a sample of 887 volunteer emergency service workers in South Australia, we conducted a study based on the JD-R framework to examine the roles of three mediators in the relationship between job characteristics and volunteer well-being. These were (i) exhaustion as a mediator in the relationships between job demands and both poor mental health and turnover intentions; and (ii) work engagement and organizational connectedness as mediators in the relationships of job resources (training and organizational support) with happiness and turnover intentions. Organizational connectedness, a relatively new construct, is a positive state of well-being that involves an emotional connection with other workers, with service recipients and with aspects of the task and the organization's values. Results indicated that all three mediators were important in explaining volunteer well-being. Specifically, job demands were positively related to exhaustion, which, in turn, was linked to ill-health and turnover intentions. Job resources were positively related to work engagement and organizational connectedness, which were, in turn, negatively related to turnover intentions. However, while organizational connectedness mediated the relationship between job resources and happiness, this was not the case for work engagement. The roles of these variables in future research in paid and voluntary work are discussed.     

The physical activity-mediated Demand–Control (pamDC) model: Linking work characteristics,leisure time physical activity,and well-being

Only recently has research begun to investigate the interplay between work characteristics, leisure time physical activity (LTPA), health, and well-being. So far, however, this research lacks a theoretical foundation. In this article, we introduce the physical activity-mediated Demand–Control (pamDC) model as a new theoretical framework. The two key ideas of the pamDC model are (1) that job demands and job control affect LTPA and (2) that LTPA partially mediates the effects of job demands and job control on health and well-being. We present eight propositions explaining how work characteristics affect LTPA, health, and well-being. For each of these propositions, we discuss empirical evidence and theoretical foundations. We then sketch a research agenda on how to adopt the pamDC model as a new theoretical framework for future research linking work characteristics, LTPA, and health. Finally, we discuss the practical implications of our new model.     

Job characteristics as predictors of ill-health and sickness absenteeism in different occupational types--a multigroup structural equation modelling approach

The objective of the present study was to test for multigroup invariance in measurement models and structural models between job characteristics, psychosocial intervening variables, health outcomes and sickness absenteeism. Four types of occupation were represented in the study: blue-collar workers ( n = 241), white-collar workers ( n = 209), elderly-care workers ( n = 338) and child-care workers ( n = 336). A first-order, six-factor multigroup confirmatory factor analysis model (i.e. measurement model) composed of two perceived job characteristics ( job autonomy and skill discretion), appraised workload, job satisfaction, stress-related ill-health and sickness absenteeism provided a good model fit. Invariance tests showed that the six-factor model fits well for all occupations. A partially recursive mediated multigroup structural model showed both similarities and differences across occupations as regards the relationships between independent latent variables ( job autonomy, skill discretion), intervening latent variables (appraised workload, job satisfaction) and dependent latent variables (stressrelated ill-health, sickness absenteeism). By comparing a generic model with occupation-specific models across occupations, this study showed that occupation-specific models were more plausible. The results indicate that it is important to examine different occupational contexts in detail to better understand how certain psychosocial factors at work influence strain in different occupations. Since job characteristics can potentially be amended, the findings have important implications for the differentiation of prevention and intervention in different occupations.     

Testing Karasek's learning and strain hypotheses on young workers in their first job

This study tests the core hypotheses of Karasek's job demand-control model: high job demands (workload) in combination with low job control (autonomy) increase strains (job dissatisfaction; strain hypothesis), whereas high job demands in combination with high job control increase learning and development in the job (here: learning new skills in the first job; learning hypothesis). These hypotheses are tested in two ways: (a) the mere combination of both job characteristics is associated with the expected outcomes, and (b) a statistical interaction between both job characteristics in predicting the outcomes is expected. A large dataset (n=2,212) of young workers in their first job was used to test all hypotheses. As young workers are presumably still in the process of adjusting themselves to their work environment, we expected that the effects of work characteristics on work outcomes would be stronger for this group than for more experienced workers. The results confirm both the strain and the learning hypothesis. We found a combined effect of both job characteristics, as well as a statistical interaction between both variables. The lowest level of job satisfaction was found in the “high strain” job, whereas the highest increase in skills was found in the “active” job. The consequences of these findings for theory and practice are discussed.