The Demands-Control-Support model, locus of control and job dissatisfaction: a longitudinal study

The Job-Demands-Control model (Karasek, 1979) has been widely studied in the job stress field, but the results obtained are frequently contradictory. Therefore, some investigations have expanded the model by including social support and personality characteristics such as locus of control. However, results obtained with these elaborated models have not been conclusive either. The present study sets out to integrate both types of expansions by simultaneously including social support at work and the employee's locus of control in a longitudinal multi-national study among 542 administrative personnel from Belgium, England, Spain, Italy and Israel. Hierarchical moderated multiple regression showed a significant 4-way interaction term (Demands ×Control ×Social support ×Locus of control) on the change in job dissatisfaction. This effect is qualified by the interaction between job demands and control only for an internal locus of control with high social support. Contrary to the prediction of the JDC model, which posits that high control has a buffering effect on job dissatisfaction, the study result indicates a damaging effect of excess control (perceived job control and high internal locus of control), specifically in high social support situations.     

ENOP: Organizational issues in hospitals

Abstract

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

Abstract

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.     

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.     

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.     

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 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 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 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 association between job skill discretion,decision authority and burnout

This paper reports on the relationship between dimensions of control (skill discretion and decision authority) and burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) among 164 human service workers. It examines the differential influence of job demands, control (skill discretion and decision authority) and social support (supervisor, co-workers, others) on each burnout dimension. Then it examines the moderating effects of higher skill discretion, higher decision authority, and higher social support on burnout. Low skill discretion was found to be associated with high emotional exhaustion and depersonalization and low personal accomplishment. The effects of decision authority were not statistically significant. High job demands were associated with high emotional exhaustion only. Social support (supervisor, co-worker, and others) was not associated with burnout when demographic variables and job characteristics were controlled for. Neither dimension of control moderated the impact of high job demands on burnout. Social support did not moderate the impact of high demands, low skill discretion, or low decision authority on any burnout dimension. The full model explained 44% of the variance in emotional exhaustion, 25% in depersonalization, and 42% in personal accomplishment. Despite its limitations, the study suggests that the Job Demand-Control model may provide a useful theoretical foundation for the study of burnout, but that the control dimensions need to be evaluated independently since they appear to be differentially related to the burnout dimensions.     

Stress demands on school administrators in Singapore

Abstract

This study investigated the use of the Occupational Stress Indicator (OSI) on school administrators in Singapore. The sample of 223 school administrators consisted of the top management group of principals and vice-principals and the middle management group of heads of department. The school administrators reported pressure at work, and consequently, higher levels of mental and physical ill health. They had high locus of control scores, indicating low internal control over their environment. However, they also reported greater use of coping strategies and higher job satisfaction. Psychometrically, the sub-scales of sources of pressure, job satisfaction, and mental and physical ill health were found to be reliable. The items of the scales of type A, locus of control and coping skills had to be re-factor analysed for the Singaporean sample. The new factors were found to have higher reliability. When the stress and job satisfaction levels of the principals/vice-principals and heads of department were compared, the heads of department reported significantly less job satisfaction and higher levels of mental and physical ill health. They perceived less internal control in their work situation.     

The effect of objective job demands on registered sickness absence spells; do personal,social and job-related resources act as moderators?

Abstract

This study applied Karaseks demand-control model, using sense of coherence (SOC), social support and job control as moderators of effects of job demands on ensuing sickness absence spells in a 3-year follow-up of 856 municipal employees. Among men the results supported the active learning hypothesis. Passive jobs predicted a high number of sickness absence spells and active jobs predicted a low number of spells. for short spells (1-3 days), the demand-control interaction, however, depended on SOC. In active jobs SOC was negatively associated with sickness absence spells; in passive jobs no such association was found. For long spells (3 days), the demand-control interaction depended on occupational level; active jobs were predictive of low absence spells among blue collar men. Among women, the results supported the strain hypothesis. The demand-control interaction, however, depended on household size. In small households, high-strain jobs predicted a high number of spells, while no increase in spells was found in active versus low-strain jobs. In larger households, the number of spells correlated positively with increasing demands even when control was good. The demand-control interaction, however, depended on SOC and spouse support. With strong SOC or spouse support, absence spells in active jobs remained on a relatively low level, otherwise active jobs led to a high number of spells. This suggests that SOC and spouse support may act as protective factors against female role conflicts associated with active jobs     

Utilizing job resources: Qualitative evidence of the roles of job control and social support in problem solving

Abstract

In resource-based models of job design, job resources, such as control and social support, are thought to help workers to solve problems. Few studies have examined this assumption. We analyzed 80 qualitative diary entries (N=29) and interviews (N=37) concerned with the in-role requirements of medical technology designers in the UK for problem solving. Four themes linked to using the resources of job control and social support for problem solving emerged. These were: (1) eliciting social support to solve problems; (2) exercising job control to solve problems; (3) co-dependence between eliciting social support and exercising job control to solve problems; and (4) using job resources to regulate affect. The results were largely supportive of the assumptions underpinning resource-based models of job design. They also indicated that the explanatory power of resource-based models of job design may be enhanced by considering interdependencies between various factors: how different job resources are used, workers' motivation to use resources, workers' knowledge of how to use resources and the use of resources from across organizational boundaries. The study provides qualitative support for the assumption that social support and job control are used to cope with demands.     

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.     

Job demands,job control,and mental health in an 11-year follow-up study: Normal and reversed relationships

Abstract

Despite numerous studies of the demand-control model, there is a need for more longitudinal studies to test not only the normal, but also the reversed and reciprocal relationships between work characteristics and mental health. There is also a need for more studies of the multiplicative interaction between demands and control with respect to mental health, which is different from the simple additive effect of the two variables. This is a longitudinal study with an exceptionally long period of follow-up (11 years), with the focus on normal as well as reciprocal and reversed causality between work characteristics and mental health, as measured by reliable instruments close to the original definitions of Karasek. The study was based on a sample of 439 Norwegian employees of different occupations who had stayed in the same profession during the follow-up period. The results were in agreement with the hypothesis that low job control, and in particular low control in combination with high demands (“high strain jobs”), has a negative effect on mental health. There was a significant multiplicative interaction between demands and control, indicating a “buffering” effect of job control. Job demands alone were not significantly associated with mental health. The reversed relationship hypothesis was supported for job demands, but not for job control.     

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.     

Job tenure as a moderator of stressor–strain relations: A comparison of experienced and new-start teachers

Abstract

Few studies have investigated the extent to which the effects of work stressors on strain change over the duration of employees’ job incumbencies. Drawing on Karasek's (1979) job demands-control-support model, the current study examined the moderating influence of job tenure (experienced versus novice worker status) on stressor-strain relations. Using a sample of 422 experienced and 248 beginning schoolteachers in Australia, job factors and job strain were assessed on two occasions, 8 months apart. Analyses revealed that the three job factors were each correlated with strain as predicted, although the (elusive) demands×control interaction effect was evidenced amongst “new-start” teachers only. The findings provide mixed support for Karasek's model, and draw attention to the need to consider the role of job tenure and career stage in studies of work stress, as work stressor-strain effects may be routinely underestimated in research that ignores these factors.     

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.     

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.     

Testing the 3-factor model of occupational stress: the impact of demands, control and social support on a mail sorting task

This study tests a 3-factor model of occupational stress, which predicts that job demands, job control and social support influence levels of strain. In a laboratory simulation of mail sorting, task demands, control and social supports were manipulated systematically. Pre- and post-task measures of self reported stress and arousal were compared across groups. Performance was measured continuously during the computer task and all 120 participants reported their perceived performance afterwards. Stress was found to be higher and perceived performance was lower in conditions of high demand; this pattern was also observed in conditions of low social support. Contrary to the hypotheses put forward in this paper, task control did not affect stress and the manipulations did not interact to produce elevated stress. However, task performance was poorer in conditions of high demand and in conditions of low control, and there was a significant interaction between demand and control for performance. Work preference measures indicated that the level of fit between ideal and actual social support influenced stress and perceived performance.