Relationship between psychosocial factors at work and incidence of perceived health problems in the GERICOTS cohort

Alternative Formulations of Job Strain and Sleep Disturbances: A Longitudinal Study in the United States

BACKGROUND

Sleep disturbances are a major public health concern in the United States, leading to adverse health outcomes. In the working population, job strain has been identified as an important risk factor for sleep disturbances, but evidence from the United States remained limited. This study aimed to examine longitudinal associations between job strain and sleep disturbances in the United States, with a focus on the alternative formulations of job strain.

METHODS

A total of 1721 participants were drawn from two waves of the Midlife in the United States (MIDUS) study, with an average 9-year follow-up period. Job strain was measured using Karasek's Job-Demand-Control model and operationalized in six formulations: standard quadrant, simplified quadrant, linear, quotient, logarithm quotient, and quartile based on quotient. Generalized Estimating Equations were used to estimate longitudinal associations of alternative formulations of job strain at baseline with sleep disturbances across follow-up. Corrected Quasi-likelihood Information Criterion (QICu) was used to assess the goodness of fit.

RESULTS

All approaches showed that higher job strain at baseline was significantly associated with an increase in sleep disturbances across follow-up. QICu scores indicated that continuous Demand-Control formulations (linear, quotient, logarithm quotient) had better model performance of 4602.66, 4604.28, and 4601.99, respectively. The logarithm quotient showed the best fit.

CONCLUSIONS

Our findings imply the importance of early workplace interventions in reducing job strain to improve sleep hygiene. They further show that the continuous formulations quantifying job strain were more consistent and robust, which provides suggestions for future workplace health research in the United States.

Workplace Psychosocial Resources and Risk of Sleep Disturbances Among Employees

Importance

Workplace psychosocial resources naturally tend to cluster in some work teams. To inform work-related sleep health promotion interventions, it is important to determine the associations between clustering of workplace resources and sleep disturbances when some resources are high while others are low and to mimic an actual intervention using observational data.

Objective

To examine whether clustering of and changes in workplace psychosocial resources are associated with sleep disturbances among workers.

Design, Setting, and Participants

This population-based cohort study used data from the Swedish Longitudinal Occupational Survey of Health (2012-2018), the Work Environment and Health in Denmark study (2012-2018), and the Finnish Public Sector Study (2008-2014), collected biennially. Statistical analysis was conducted from November 2020 to June 2022.

Exposure

Questionnaires were distributed measuring leadership quality and procedural justice (ie, vertical resources) as well as collaboration culture and coworker support (ie, horizontal resources). Resources were divided into clusters of general low, intermediate vertical and low horizontal, low vertical and high horizontal, intermediate vertical and high horizontal, and general high.

Main Outcomes and Measures

Odds ratios (ORs) and 95% CIs were reported from logistic regression models for the associations between the clustering of resources and concurrent and long-term sleep disturbances. Sleep disturbances were measured by self-administered questionnaires.

Results

The study identified 114 971 participants with 219 982 participant-observations (151 021 [69%] women; mean [SD] age, 48 [10] years). Compared with participants with general low resources, other groups showed a lower prevalence of sleep disturbances, with the lowest observed in the general high group concurrently (OR, 0.38; 95% CI, 0.37-0.40) and longitudinally after 6 years (OR, 0.52; 95% CI, 0.48-0.57). Approximately half of the participants (27 167 participants [53%]) experienced changes in resource clusters within 2 years. Improvements in vertical or horizontal dimensions were associated with reduced odds of persistent sleep disturbances, and the lowest odds of sleep disturbances was found in the group with improvements in both vertical and horizontal dimensions (OR, 0.53; 95% CI, 0.46-0.62). A corresponding dose-response association with sleep disturbances was observed for decline in resources (eg, decline in both dimensions: OR, 1.74; 95% CI, 1.54-1.97).

Conclusions and Relevance

In this cohort study of workplace psychosocial resources and sleep disturbances, clustering of favorable resources was associated with a lower risk of sleep disturbances.

Changes in effort-reward imbalance at work and risk of onset of sleep disturbances in a population-based cohort of workers in Denmark

Objective/background

Associations between exposure to effort-reward imbalance at work (eg, high time pressure/low appreciation) and risk of sleep disturbances have been reported, but the direction of the effect is unclear. The present study investigated changes in effort-reward imbalance and risk of concomitant and subsequent onset of sleep disturbances.

Methods

Participants with sleep disturbances at baseline were excluded. We included participants from a population-based cohort in Denmark (n = 8,464, 53.6% women, mean age = 46.6 years), with three repeated measurements (2012 (T₀); 2014 (T₁); 2016 (T₂)). Changes in effort-reward imbalance (T₀-T₁) were categorized into 'increase', 'decrease' and 'no change'. Self-reported sleep disturbances (difficulties initiating or maintaining sleep, non-restorative sleep, daytime tiredness) were dichotomized (presence versus absence). We regressed concomitant (T₁) and subsequent (T₂) sleep disturbances on changes in effort-reward imbalance (T₀-T₁) and calculated odds ratios (OR) and 95% confidence intervals, adjusted for sex, age, education and cohabitation.

Results

At follow-up, 8.4% (T₁) and 12.5% (T₂) reported onset of sleep disturbances. Increased effort-reward imbalance was associated with concomitant sleep disturbances (T₁) (OR = 3.16, 2.56-3.81), whereas decreased effort-reward imbalance was not (OR = 1.22, 0.91-1.63). There was no association between increased effort-reward imbalance and subsequent sleep disturbances (T₂) (OR = 1.00, 0.74-1.37). Results were similar for men and women.

Conclusions

Increased effort-reward imbalance was associated with a three-fold higher risk of concomitant onset of sleep disturbances at two-year follow-up, but not subsequent onset of sleep disturbances at four-year follow-up, indicating that changes in effort-reward imbalance have immediate rather than delayed effects on sleep impairment. It is possible that the results from the two-year follow-up were to some extent affected by reverse causality.

Are Insomnia Type Sleep Problems Associated With a Less Physically Active Lifestyle? A Cross-Sectional Study Among 7,700 Adults From the General Working Population

Background: Sleep problems are common in the general population and negatively affect both private and work life. A vicious circle may exist between poor sleep and an unhealthy lifestyle. For example, poor sleep may drain the energy to do health-promoting physical activity during leisure-time after work. The aim of the present study was to investigate the association between sleep problems and the duration of low- and high-intensity leisure-time physical activity in sedentary and physical workers. Methods: This cross-sectional study employ data from the Danish Work Environment Cohort Study in 2010, where currently employed wage-earners in Denmark on daytime schedule (N = 7,706) replied to questions about sleep quality (cf. the Bergen Insomnia Scale) and participation in low- and high-intensity leisure-time physical activity. Associations were modeled using general linear models controlling for various confounders. Results: Workers with high levels of sleep problems reported less high-intensity leisure-time physical activity. Specifically, the weekly duration of high-intensity leisure-time physical activity was 139 (95%CI 111-168), 129 (95%CI 101-158), and 122 (95%CI 92-151) min in sedentary workers with sleep problems < 1, 1-3, and ≥3 days per week, respectively. The same pattern was observed among physical workers. In sedentary workers ≥50 years, the fully adjusted model showed a weekly duration in high-intensity physical activity during leisure of 122 (95%CI 83-161), 102 (95%CI 64-141), and 90 (95%CI 51-130) among those with sleep problems < 1, 1-3, and ≥3 days per week, respectively. Conclusions: Workers, particularly sedentary older workers, having sleep problems report less high-intensity leisure-time physical activity. These data suggest that a vicious circle may indeed exist between poor sleep and reduced leisure-time physical activity.

Association between insomnia and job stress: a meta-analysis

PURPOSE

Insomnia has become one of the foremost health concerns among workers. Despite a significant number of epidemiological studies have reported on the correlation between insomnia and job stress, comprehensive evidence remains insufficient. Therefore, this research seeks to provide evidence with greater reliability, through summarizing relevant contemporary literature via a meta-analysis.

METHODS

Literature from across Europe and Asia that was of both a prospective and cross-sectional design was included, if well-controlled odds ratios were available. The meta-analysis was undertaken in accordance with the guidelines devised by PRISMA, including tests for publication bias and heterogeneity.

RESULTS

High job stress was associated with a greater risk of suffering from insomnia (random OR = 1.73, 95% CI 1.46-2.05), and the correlation between effort-reward imbalance and insomnia was statistically significant (random OR = 2.63, 95% CI 1.22-5.69). Higher demand was correlated to a relatively greater risk of insomnia (random OR = 1.35, 95% CI 1.20-1.51), while the pooled effect of low control was not found to be statistically significant. The summary random odds ratio of heavy workload was 2.76, and a pooled odds ratio of 1.67 (fixed, 95% CI 1.11-2.52) was calculated in low social support. With regard to the overall population, work-family conflict was correlated with insomnia (random OR = 2.32, 95% CI 1.53-3.51). The subgroup analysis provided comparable outcomes, for both males (fixed OR = 1.97, 95% CI 1.50-2.57) and females (random OR = 2.80, 95% CI 1.30-6.05). Egger's regression indicated that publication bias may be apparent in the syntheses of effort-reward imbalance, low social support, and work-family conflict (p < 0.05). Heterogeneity was caused by design, measuring the exposure or outcome, in addition to the region where the research was conducted.

CONCLUSIONS

The correlation between insomnia and higher levels of job stress, effort-reward imbalance, high demand, heavy workload, and low social support was determined. Publication bias and heterogeneity were partially observed. Furthermore, future studies with improved methodologies and a focus on mechanisms are anticipated.

Work and Sleep--A Prospective Study of Psychosocial Work Factors, Physical Work Factors, and Work Scheduling

STUDY OBJECTIVES

There is limited knowledge about the prospective relationship between major work characteristics (psychosocial, physical, scheduling) and disturbed sleep. The current study sought to provide such knowledge.

DESIGN

Prospective cohort, with measurements on two occasions (T1 and T2) separated by two years.

SETTING

Naturalistic study, Sweden.

PARTICIPANTS

There were 4,827 participants forming a representative sample of the working population.

MEASUREMENTS AND RESULTS

Questionnaire data on work factors obtained on two occasions were analyzed with structural equation modeling. Competing models were compared in order to investigate temporal relationships. A reciprocal model was found to fit the data best. Sleep disturbances at T2 were predicted by higher work demands at T1 and by lower perceived stress at T1. In addition, sleep disturbances at T1 predicted subsequent higher perception of stress, higher work demands, lower degree of control, and less social support at work at T2. A cross-sectional mediation analysis showed that (higher) perceived stress mediated the relationship between (higher) work demands and sleep disturbances; however, no such association was found longitudinally.

CONCLUSIONS

Higher work demands predicted disturbed sleep, whereas physical work characteristics, shift work, and overtime did not. In addition, disturbed sleep predicted subsequent higher work demands, perceived stress, less social support, and lower degree of control. The results suggest that remedial interventions against sleep disturbances should focus on psychosocial factors, and that such remedial interventions may improve the psychosocial work situation in the long run.

Income inequality as a moderator of the relationship between psychological job demands and sickness absence, in particular in men: an international comparison of 23 countries

OBJECTIVES

The aim of this study was to investigate whether more sickness absence is reported in countries with higher income inequality than elsewhere, and whether the level of income inequality moderates the association between psycho-social job demands and sickness absence.

METHODS

Our analysis is based on the Fifth European Working Conditions Survey that compared 23 European countries. We performed multi-level regression analysis. On the macro-level of analysis we included the Gini-Index as measure of inequality. On the micro-level of analysis we followed the Karasek-Theorell model and included three scales for psychological job demands, physical job demands, and decision latitude in the model. The model was stratified by sex.

RESULTS

We found that, in countries with high income inequality, workers report significantly more sickness absence than workers in countries with low income inequality. In addition we found that the level of income inequality moderates the relationship between psychological job demands and sickness absence. High psychological job demands are significantly more strongly related to more days of sickness absence in countries with low income inequality than in countries with high income inequality.

CONCLUSIONS

As the nature and causal pathways of cross-level interaction effects still cannot be fully explained, we argue that future research should aim to explore such causal pathways. In accordance with WHO recommendations we argue that inequalities should be reduced. In addition we state that, particularly in countries with low levels of income inequality, policies should aim to reduce psychological job demands.

The impact of the HDI on the association of psychosocial work demands with sickness absence and presenteeism

BACKGROUND

The purpose of this study was to determine whether psychosocial work demands have a different impact on sickness absence and presenteeism in countries with a high vs. countries with a low Human Development Index (HDI).

METHODS

This article is based on an analysis of the fifth European Working Conditions Survey. We investigated single items as well as complex constructs and indices. Sickness absence and presenteeism were measured as outcome variables. Following the model of Karasek and Theorell, we measured the HDI at the macro level and psychosocial job demands at the micro level as independent variables.

RESULTS

The multivariate multilevel analysis reveals a significant association between the HDI and the number of days recorded for sickness absence. In countries with a higher HDI, people report a lower number of days with sickness absence. Higher psychosocial job demands are associated with poorer health. There are significant cross-level interaction effects between psychosocial job demands and the HDI for these associations. Psychosocial job demands are stronger associated with sickness absence and presenteeism in high-HDI than in low-HDI countries.

CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH

We argue that Public Health Actions that are connected to work characteristics need to take into consideration the level of HDI of the countries. In low- and high-HDI countries, different actions could be necessary to reach the needs of the working population.

Psychosocial stress and multi-site musculoskeletal pain: a cross-sectional survey of patient care workers

The aim of this study was to assess the relationship between psychosocial factors at work and multi-site musculoskeletal pain among patient care workers. In a survey of 1,572 workers from two hospitals, occupational psychosocial factors and health outcomes of workers with single and multi-site pain were evaluated using items from the Job Content Questionnaire that was designed to measure psychological demands, decision latitude, and social support. An adapted Nordic Questionnaire provided data on the musculoskeletal pain outcome. Covariates included body mass index, age, gender, and occupation. The analyses revealed statistically significant associations between psychosocial demands and multi-site musculoskeletal pain among patient care associates, nurses, and administrative personnel, both men and women. Supervisor support played a significant role for nurses and women. These results remained statistically significant after adjusting for covariates. These results highlight the associations between workplace psychosocial strain and multi-site musculoskeletal pain, setting the stage for future longitudinal explorations.

Anti-clockwise rotating shift work and health: would you prefer 3-shift or 4-shift operation?

BACKGROUND

We explored the association between work schedules involving nightshifts and selected measures of health and whether these associations differed among those working in either 3- or 4-shift cycles.

METHODS

Employees at a German industrial company who worked on a fixed daytime schedule or on one involving nightshifts were invited to participate in this cross-sectional study. Work schedules involving a nightshift were organized into either 3 or 4 shifts rotated anti-clockwise on a weekly basis. Health characteristics included a range of clinical and physiological measures and self-reported data on stress and sleep quality. We assessed the independent association of work schedules involving any nightshift and these health characteristics in separate regression analyses, adjusting for age, gender, smoking, and alcohol consumption.

RESULTS

Nightshift work (N = 133) in general and 3-shift-work (N = 53) in particular was associated with decreased sleep quality (P < 0.001). Compared to those working daytime (N = 632), employees working on a 3-shift cycle had higher adjusted odds of meeting the definition of metabolic syndrome (OR = 2.56 [1.38, 4.75]). Employees working 4-shift cycles were somewhat less likely to have metabolic syndrome (OR = 1.22 [0.73, 2.05]) and had higher parasympathetic activity measured by heart rate variability (OR = 2.20 [1.04, 4.63]).

CONCLUSIONS

Our data suggest important relationships between shift schedule and a selected group of objective and subjective health measures. Additional research that further clarifies potential mechanisms underlying these relationships is needed.