Formulations of Job Strain and Psychological Distress: A Four-year Longitudinal Study in Japan

Background

Different job strain formulations based on the Job Demand-Control model have been developed. This study evaluated longitudinal associations between job strain and psychological distress and whether associations were influenced by six formulations of job strain, including quadrant (original and simplified), subtraction, quotient, logarithm quotient, and quartile based on quotient, in randomly selected Japanese workers.

Methods

Data were from waves I and II of the Survey of Midlife in Japan (MIDJA), with a 4-year follow-up period. The study sample consisted of 412 participants working at baseline and had complete data on variables of interest. Associations between job strain at baseline and psychological distress at follow-up were assessed via multivariable linear regression, and results were expressed as β coefficients and 95% confidence intervals including R2 and Akaike information criterion (AIC) evaluation.

Results

Crude models revealed that job strain formulations explained 6.93-10.30% of variance. The AIC ranged from 1475.87 to 1489.12. After accounting for sociodemographic and behavioral factors and psychological distress at baseline, fully-adjusted models indicated significant associations between all job strain formulations at baseline and psychological distress at follow-up: original quadrant (β: 1.16, 95% CI: 0.12, 2.21), simplified quadrant (β: 1.01, 95% CI: 0.18, 1.85), subtraction (β: 0.39, 95% CI: 0.09, 0.70), quotient (β: 0.37, 95% CI: 0.08, 0.67), logarithm quotient (β: 0.42, 95% CI: 0.12, 0.72), and quartile based on quotient (β: 1.22, 95% CI: 0.36, 2.08).

Conclusion

Six job strain formulations showed robust predictive power regarding psychological distress over 4 years among Japanese workers.

Depression symptoms mediate the association between workplace stress and interleukin 6 in women, but not men: The Whitehall II study

Workplace stress and depression are positively related with inflammation, and each other. Low-grade inflammation and concurrent high levels of workplace stress or depression has been related with future morbidity. The potential pathway between constructs however, remains elusive. For the first time, this study explored the concurrent relationship between workplace stress, depressive symptomology and low-grade inflammation, and considered the role of gender in these relationships. Data from the Whitehall II cohort study (N ​= ​2528, M_age ​= ​57.01, 23.7% females) provided measures of workplace stress (job demand-control; JDC), depressive symptomology (Centre for Epidemiological Studies Depression scale; CES-D) and circulating inflammatory markers, interleukin-6 (IL-6) and C-reactive protein (CRP) collected on the same day from a single time point. Females had higher workplace stress, depressive symptoms and lower serum IL-6 concentrations. For males, higher workplace stress was associated with higher depressive symptoms. For females, higher depressive symptoms were related with elevated IL-6 levels, and both higher workplace stress and IL-6 levels were associated with higher depressive symptoms. Higher depressive symptoms were related with higher CRP levels in men only. Higher depressive symptoms statistically mediated the relationship between higher workplace stress and IL-6 levels in females only, b ​= ​0.016, CI [0.002, 0.039]. Females in this large cohort had higher levels of job strain, depression and lower IL-6 concentrations than males. In females, higher depressive symptoms were associated with higher serum IL-6 levels and workplace stress was not. Considered together, these findings suggest that low job control may be more apparent in females than males, but it is primarily negative affect that drives the positive relationship between work stress and serum IL-6 concentrations in females. Replicating the current design with a suitably proximal follow-up is required to determine if the associations identified are causal.

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Females had higher workplace stress, depressive symptoms and lower IL-6.

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Association between stress, depression and inflammation was stronger in women.

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Among females, depressive symptoms and not stress associated with serum IL-6. .

[Psychosocial stress at work and disease risks : Scientific evidence and implications for practice]

The modern working world makes a significant contribution to the development of diseases, which goes far beyond the field of traditional occupational diseases. Despite technological progress and successful medical healthcare, distinct widely disseminated psychosocial working conditions contribute to a remarkable burden of work-related diseases. By inducing chronic activation of psychobiological stress reactions, they promote the development of various physical and mental disorders. To identify "toxic" constellations within the complexity and variability of modern work environments, a theoretical model is required. It aims at delineating core critical elements at a level of generalization that enables their identification in a wide range of occupations. This article describes the leading theoretical work stress models in the international research and it demonstrates their contribution towards explaining elevated disease risks among employees. Research based on prospective epidemiologic cohort studies focused specifically on depressive disorders and coronary heart diseases. Two theoretical concepts received particular attention, the demand-control and the effort-reward imbalance models. Results derived from meta-analyses indicate increased relative risks of these disorders in the range of 35-80% among those exposed to these stressors compared to nonexposed groups. Finally, practical implications of this scientific evidence for worksite screening and health promoting activities are discussed.

Trajectories of job demands and control: risk for subsequent symptoms of major depression in the nationally representative Swedish Longitudinal Occupational Survey of Health (SLOSH)

Purpose

Depression is a global health concern. High job demands, low job control, and the combination (high strain) are associated with depression. However, few longitudinal studies have investigated changed or repeated exposure to demands and control related to depression. We investigated how trajectories of exposure to job demands and control jointly influence subsequent depression.

Methods

We included 7949 subjects from the Swedish Longitudinal Occupational Survey of Health, who completed questionnaires of perceived job demands and control, and depressive symptoms from 2006 to 2014. None of them were depressed between 2006 and 2012. Univariate and joint group-based trajectory models identified groups with similar development of demands and control across 2006–2012. Logistic regression estimated the risk for symptoms of major depression in 2014 according to joint trajectory groups.

Results

The joint trajectory model included seven groups, all with fairly stable levels of demands and control over time. Subjects in the high strain and active (high demands and high control) trajectories were significantly more likely to have subsequent major depressive symptoms compared to those having low strain, controlling for demographic covariates (OR 2.15; 95% Cl 1.24–3.74 and OR 2.04; 95% CI 1.23–3.40, respectively). The associations did not remain statistically significant after adjusting for previous depressive symptoms in addition to demographic covariates.

Conclusions

The results indicate that the levels of job demands and control were relatively unchanged across 6 years and suggest that long-term exposure to a high strain or active job may be associated with increased risk for subsequent depression.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-017-1277-0) contains supplementary material, which is available to authorized users.

Stressors, Appraisal of Stressors, Experienced Stress and Cardiac Response: A Real-Time, Real-Life Investigation of Work Stress in Nurses

BACKGROUND

Stress in health care professionals may reflect both the work and appraisal of work and impacts on the individuals, their patients, colleagues and managers.

PURPOSE

The purpose of the present study is to examine physiological and psychological effects of stressors (tasks) and theory-based perceptions of work stressors within and between nurses in real time.

METHODS

During two work shifts, 100 nurses rated experienced stress, affect, fatigue, theory-based measures of work stress and nursing tasks on electronic diaries every 90 min, whereas heart rate and activity were measured continuously.

RESULTS

Heart rate was associated with both demand and effort. Experienced stress was related to demand, control, effort and reward. Effort and reward interacted as predicted (but only within people). Results were unchanged when allowance was made for work tasks.

CONCLUSIONS

Real-time appraisals were more important than actual tasks in predicting both psychological and physiological correlates of stress. At times when effort was high, perceived reward reduced stress.