Assessing the cumulative effects of stress: The association between job stress and allostatic load in a large sample of Chinese employees

Abstract

Job stress can lead to various system dysfunctions, but until now no reliable biomarkers for its assessment have been identified. Allostatic load (AL) is an index that enables the cumulative effect on the body of chronic stress to be assessed, and is derived from a set of relevant biological measures. In this study, a 13-parameter index (building on the original 10-item index) was used to examine the relationship between job strain and AL. Participants were 1219 healthy Chinese employees. Job strain was measured using the Job Content Questionnaire, and AL was assessed by various possible stress responses, including blood pressure, cholesterol, indicators of glucose metabolism, and hormone and inflammation markers. AL in the high job strain group differed sharply from that in the low job strain group. The AL score was positively associated with age and educational level. Several individual parameters also differed between the two groups. Men scored significantly higher on AL and cardiovascular and metabolic health outcomes, whereas for women the associations appeared in the biological indicators. Analyses indicated that decision latitude (DL) and job demands were significantly related to AL. Job demands correlated significantly with the primary biological indicators and DL with the secondary health outcomes. In conclusion, this study provides evidence of the value of measuring allostatic load in assessing the chronic effects of job stress.     

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 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.     

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 Job Demand-Control (-Support) Model and psychological well-being: A review of 20 years of empirical research

The Job Demand-Control (JDC) model (Karasek, 1979) and the Job Demand-Control-Support (JDCS) model (Johnson, and Hall, 1988) have dominated research on occupational stress in the last 20 years. This detailed narrative review focuses on the JDC(S) model in relation to psychological well-being. It covers research from 63 samples, published in the period 1979-1997. In the review a distinction is drawn between two different hypotheses prevailing in research on the models. According to the strain hypothesis of the JDC model, employees working in a high-strain job (high demands-low control) experience the lowest well-being. The buffer hypothesis states that control can moderate the negative effects of high demands on well-being. Translating these hypotheses to the expanded JDCS model, the iso-strain hypothesis predicts the most negative outcomes among workers in an iso-strain job (high demands-low control-low social support/isolation), whereas the buffer hypothesis states that social support can moderate the negative impact of high strain on well-being. Although the literature gives considerable support for the strain and iso-strain hypotheses, support for the moderating influence of job control and social support is less consistent. The conceptualization of demands and control is a key factor in discriminating supportive from nonsupportive studies. Only aspects of job control that correspond to the specific demands of a given job moderate the impact of high demands on well-being. Furthermore, certain subpopulations appear to be more vulnerable to high (iso)strain, whereas others benefit more from high control. On the basis of the results of this review, suggestions for future research and theoretical development are formulated.     

The Job Demand-Control (-Support) Model and psychological well-being: a review of 20 years of empirical research

The Job Demand-Control (JDC) model (Karasek, 1979) and the Job Demand-Control-Support (JDCS) model (Johnson, and Hall, 1988) have dominated research on occupational stress in the last 20 years. This detailed narrative review focuses on the JDC(S) model in relation to psychological well-being. It covers research from 63 samples, published in the period 1979-1997. In the review a distinction is drawn between two different hypotheses prevailing in research on the models. According to the strain hypothesis of the JDC model, employees working in a high-strain job (high demands-low control) experience the lowest well-being. The buffer hypothesis states that control can moderate the negative effects of high demands on well-being. Translating these hypotheses to the expanded JDCS model, the iso-strain hypothesis predicts the most negative outcomes among workers in an iso-strain job (high demands-low control-low social support/isolation), whereas the buffer hypothesis states that social support can moderate the negative impact of high strain on well-being. Although the literature gives considerable support for the strain and iso-strain hypotheses, support for the moderating influence of job control and social support is less consistent. The conceptualization of demands and control is a key factor in discriminating supportive from nonsupportive studies. Only aspects of job control that correspond to the specific demands of a given job moderate the impact of high demands on well-being. Furthermore, certain subpopulations appear to be more vulnerable to high (iso)strain, whereas others benefit more from high control. On the basis of the results of this review, suggestions for future research and theoretical development are formulated.     

Helping people to sort it out: The role of social support in the Job Strain Model

This paper reports three studies of occupational stress investigating the role of social support as an intervening variable in the Job Strain Model (Karasek, 1979). A computer simulated mail-sorting work environment was used to assess the effect of demands, control and social support on measures of strain, satisfaction, and perceived and actual task performance. The first experiment ( N =60) tests the basic Job Strain Model by manipulating levels of task demand and control. The second experiment ( N =120) compares high and low levels of two types of social support (informational support and emotional support) to determine whether and how they interact with extreme conditions of the Job Strain Model (high strain and low strain). The final experiment ( N =90) investigates positive and negative forms of social support (praise and criticism) in relation to extreme job strain conditions. Results show that the job strain model is consistent with the stress and performance data, although stress showed no Demand ×Control interaction. Social supports increased arousal, satisfaction and perceived performance, but did not affect stress or task performance. Moreover, contrary to buffer theories, social supports did not interact with the job strain variables. Congruence between preferred and experienced emotional support levels also predicted performance.     

Helping people to sort it out: The role of social support in the Job Strain Model

This paper reports three studies of occupational stress investigating the role of social support as an intervening variable in the Job Strain Model (Karasek, 1979). A computer simulated mail-sorting work environment was used to assess the effect of demands, control and social support on measures of strain, satisfaction, and perceived and actual task performance. The first experiment ( N =60) tests the basic Job Strain Model by manipulating levels of task demand and control. The second experiment ( N =120) compares high and low levels of two types of social support (informational support and emotional support) to determine whether and how they interact with extreme conditions of the Job Strain Model (high strain and low strain). The final experiment ( N =90) investigates positive and negative forms of social support (praise and criticism) in relation to extreme job strain conditions. Results show that the job strain model is consistent with the stress and performance data, although stress showed no Demand 2 Control interaction. Social supports increased arousal, satisfaction and perceived performance, but did not affect stress or task performance. Moreover, contrary to buffer theories, social supports did not interact with the job strain variables. Congruence between preferred and experienced emotional support levels also predicted performance.     

Role stress among Canadian white-collar workers

The incidence of various stressors at work and outside work was examined in a group of public service workers with a large Canadian federal government department. Workers were either in clerical, technical and supervisory ('officers'), or management positions. Measures of work stress included role stressors (load, insufficiency, conflict ambiguity and responsibility), as well as stress due to the physical environment. Both life events and daily hassles were included as measures of non-work stress. The consequences of stress were considered in terms of vocational, psychological, interpersonal, and physical strain, as well as in terms of job satisfaction and organizational commitment. Potential moderators of stress included social support and self-esteem. Among work stressors conflict, ambiguity and insufficiency were the more closely associated with vocational outcomes. MANCOVA followed by discriminant function analysis showed that clerical workers were distinguished by higher levels of insufficiency, officers by higher levels of conflict and the lowest levels of job satisfaction and organizational commitment, and managers by higher levels of perceived responsibility for others. The results are discussed in terms of social role theory.     

Job stress, social support, job satisfaction and absenteeism among offshore oil personnel

The major aim of this study was to examine how job stress in the offshore working environment may affect workers experience of strain. This study also analyses both the main and moderator effect of social support on the association between job stress and strain. The association between strain and absenteeism is also analysed. The analyses are based on a self-completion questionnaire survey among employees on offshore oil installations in the Norwegian part of the North Sea (n = 1137). The data collection was carried out in 1994. A similar study was conducted in 1990. Job stress was found to be associated with job dissatisfaction, as well as experience of strain. Social support from a supervisor had a main effect on strain. Some evidence of the moderating effects of social support were found. The employees who had been absent from work experienced most strain. It is concluded that job stress predicted job dissatisfaction and strain. In turn, strain and absenteeism were associated with each other. These results suggest that improving organizational and social factors should be the focal area in health promotion in the offshore oil industry.     

The New Zealand government approach to stress and fatigue

Abstract

Self-control involves inhibiting undesired behaviours and emotions, and it can be particularly relevant in the service sectors. Recent theoretical developments in cognitive and social psychology suggest that the demands on an individual of exercising self-control have an effect as a source of stress at work. In turn, burnout could be associated with being unable to meet those demands. It was expected that cognitive control deficits, as assessed by a questionnaire measure of self-reported failures in perception, memory, and action, would function as a vulnerability factor in the relationship between self-control demands and indicators of job strain. Data from 630 staff members of a German municipal administration revealed significant main effects of both self-control demands and cognitive control deficits on the burnout dimensions of emotional exhaustion and depersonalization. Both predictors were positively related to burnout. In addition, the results provided clear evidence of the vulnerability hypothesis of cognitive control deficits. By way of contrast, musculoskeletal complaints did not reflect similar main and interactive effects of self-control demands and cognitive control deficits. The requirements for self control in the service sector are expected to increase as the sector expands, and the practical implications for this are discussed.     

Back to basics: Re-examination of Demand-Control Theory of occupational stress

The Demand-Control model of occupational stress posits an interaction between job demands and job control predicting psychological strain, but previous research has found such an interaction only rarely or inconsistently. Such research, however, has often failed to measure either demands or strain faithfully to the model's constructs, or has simply failed to test for a statistical interaction. The present study corrected these shortcomings by going back to basics. Using a sample of 115 employees in a manufacturing company, it operationalized the variables more consistently with their original conceptualizations. However, when the hypothesized Demand-Control interaction was then tested, it still failed. Outcomes other than psychological strain (e.g. job dissatisfaction) were related negatively rather than positively to demands. This highlights the difference between psychological strain and dissatisfaction and casts doubt on models positing dissatisfaction as an intervening variable between stressors and strains.     

Job stress, satisfaction and mental health of factory workers in Bangladesh

The present study examined the relationship between job stress, job satisfaction and mental health, and attempted to assess the effects of job stress on different parameters of satisfaction and mental health in the context of two groups of Bangladeshi factory workers. There were 26 subjects in a 'high stress' group and 33 in a 'low stress' group. Individual data were collected by using the Stress and Arousal Checklist, the Job Satisfaction Scale, the General Health Questionnaire, absenteeism by sick leave, a self-esteem at work scale and heart rate monitor. Chi-square and t-tests were applied in the analyses of these data by group. The results, quite expectedly, showed that a greater number of high stress subjects were dissatisfied and had poorer mental health than low stress subjects. The results also showed that low stress subjects were significantly more satisfied and possessed better mental health than the high stress subjects. It would appear that the experience of stress plays an important role in determining the quality of working life of Bangladeshi factory workers having similar consequences in terms of health and well-being to those observed in developed countries. The dynamics of absenteeism in Bangladesh are discussed.     

The Job Demands-Job Control Model and absence behaviour: results of a 3-year longitudinal study

Empirical results of earlier studies only marginally supported the relevance of Karasek's Job Demands-Job Control Model for absence behaviour. Since longitudinal studies with respect to these relations were largely lacking, a four-wave panel study was carried out using data from 1755 male employees of a technical maintenance firm in the public sector. Job demands, job control, physical working conditions, and the employee's age, education, and health were measured in one year and absenteeism in the same year and in the next 3 years. Data were analysed with linear regression and Poisson regression techniques. The Poisson regression technique was superior to the linear regression technique in explaining absence. Age, health and prior absence were the best predictors of later absence behaviour. With respect to the Job Demands-Job Control Model, the main findings of the study were (1) that job control was significantly associated with a low number of simultaneous and later absence days, and (2) that, contrary to expectations, job demands were also related to a low number of simultaneous and later absence days. These results hold when age, health, education, prior absence, and working conditions are controlled for. Job control and job demands did not predict later absence frequency. In the discussion it is suggested that a high level of job demands may not only be harmful for the well-being of employees but also work as 'a pressure to attend'.     

Back to basics: Re-examination of Demand-Control Theory of occupational stress

The Demand-Control model of occupational stress posits an interaction between job demands and job control predicting psychological strain, but previous research has found such an interaction only rarely or inconsistently. Such research, however, has often failed to measure either demands or strain faithfully to the model's constructs, or has simply failed to test for a statistical interaction. The present study corrected these shortcomings by going back to basics. Using a sample of 115 employees in a manufacturing company, it operationalized the variables more consistently with their original conceptualizations. However, when the hypothesized Demand-Control interaction was then tested, it still failed. Outcomes other than psychological strain (e.g. job dissatisfaction) were related negatively rather than positively to demands. This highlights the difference between psychological strain and dissatisfaction and casts doubt on models positing dissatisfaction as an intervening variable between stressors and strains.     

The importance of context specificity in work stress research: A test of the Demand-Control-Support model in academics

The Demand-Control (D-C) (Karasek, 1979) and the Demand-Control-Support (D-C-S) (Johnson & Hall, 1988; Johnson, Hall, & Theorell, 1989; Karasek & Theorell, 1990) models of work stress suggest that jobs with high demands and low control (and low support) are stressful. In line with the support in the literature for context-specificity in occupational stress research (Sparks & Cooper, 1999) and the limited and even contradictory support for interaction effects, the main aim of the present study was to examine how the D-C-S model applied in a well-defined occupational group. Using hierarchical regression analyses, and controlling for negative affect, the D-C-S model accounted for 26%, 6%, and 8% of the variance in job satisfaction, psychological distress and burnout, respectively, among 166 academics in a UK university. No two-way or three-way interactive effects were evident, but additive effects of job demands and control on psychological well-being and of job demands and support on both burnout and job satisfaction were shown, corroborating research showing that high job strain is linked to ill health and job dissatisfaction in this homogenous occupational sample. It is recommended that, in future, research includes more variables that are specific to a particular occupation.     

Specific relationships between psychosocial job conditions and job-related stress: A three-level analytic approach

This cross-sectional questionnaire study presents a multi-level analysis on 2565 workers in 188 departments in 36 organizations in the Netherlands. A three-level model is used in which individual workers are nested within departments, which in turn are nested within organizations. Research questions concern (1) the amount and distribution of variance in job-related stress explained for the three levels in the study (individuals, departments, organizations), and (2) the specificity of relationships between psychosocial job demands and job-related stress in the three-level model. Well-being showed slightly more raw variance to be explained at supra-individual levels than strain. The full regression model explained about 35% of the total variance in both work-related strain and well-being. Psychosocial job conditions did not exceed the expected amount of 10 to 15% contribution to this explained variance. These results do not differ from comparable studies that do not use multi-level analysis. The variance distribution in the full model, however, showed unexplained variance to be located at the individual level for both strain and well-being, and at the departmental level only for well-being. This last finding shows a direction for possible improvement of work stress models. Specificity of relationships was also shown: psychological job demands were more strongly related to strain, whereas job content variables (i.e. job variety, job control) were more strongly related to well-being. Results also suggested that social support was more strongly associated with well-being than with strain. Well-being appeared to have a more widely varying range of predictors than strain.     

Specific relationships between psychosocial job conditions and job-related stress: A three-level analytic approach

This cross-sectional questionnaire study presents a multi-level analysis on 2565 workers in 188 departments in 36 organizations in the Netherlands. A three-level model is used in which individual workers are nested within departments, which in turn are nested within organizations. Research questions concern (1) the amount and distribution of variance in job-related stress explained for the three levels in the study (individuals, departments, organizations), and (2) the specificity of relationships between psychosocial job demands and job-related stress in the three-level model. Well-being showed slightly more raw variance to be explained at supra-individual levels than strain. The full regression model explained about 35% of the total variance in both work-related strain and well-being. Psychosocial job conditions did not exceed the expected amount of 10 to 15% contribution to this explained variance. These results do not differ from comparable studies that do not use multi-level analysis. The variance distribution in the full model, however, showed unexplained variance to be located at the individual level for both strain and well-being, and at the departmental level only for well-being. This last finding shows a direction for possible improvement of work stress models. Specificity of relationships was also shown: psychological job demands were more strongly related to strain, whereas job content variables (i.e. job variety, job control) were more strongly related to well-being. Results also suggested that social support was more strongly associated with well-being than with strain. Well-being appeared to have a more widely varying range of predictors than strain.     

Job stress in two different care-giving contexts: A study of professional and semi-professional health personnel in Norway

The study examined the relationship between priorities in job tasks and stress-related experiences among health workers in long-term care (n = 322). Employees' priorities were measured in terms of role orientation, represented by two different 'profiles': expressive and instrumental role orientation. Job stress assessed included potential workload and emotional involvement. Stress-related experiences assessed were psychosomatic and interpersonal consequences. Sub-group analyses were used to test the nature of the relationship between stressors and the criterion variables in the study. The sub-group analyses indicated that role orientation only partially moderated the relationship between job stressors and employees' stress-related experiences. It was in relation to emotional involvement that role orientation was a relatively strong moderator.