Perceived job stress and incidence of coronary events: 3-year follow-up of the Belgian Job Stress Project cohort

Work-Related Stress and Occurrence of Cardiovascular Disease: A 13-Year Prospective Study

OBJECTIVE

The aim of the study is to investigate the influence of work-related psychological and physical stresses on risk of cardiovascular disease (CVD).

METHODS

A total of 5651 CVD-free participants older than 50 years from the Survey of Health, Ageing and Retirement in Europe were followed up for 13 years to detect incident CVD. Work-related stress was assessed using job strain and job reward questionnaire. Cox regression model was used to estimate the association.

RESULTS

High physical demands (hazard ratio [HR], 1.30) and low reward (HR, 1.19) compared with their counterparts, as well as active physical jobs (HR, 1.41) and high physical strain (HR, 1.45) in comparison with low physical strain were associated with higher risk of incident CVD after adjusting for confounders. However, combining physically stressful jobs with low reward did not further increase the CVD risk.

CONCLUSIONS

Avoiding physically stressful jobs or providing appropriate reward may reduce the occurrence of CVD.

Chronic Stress A Potential Suspect Zero of Atherosclerosis: A Systematic Review

Atherosclerosis (AS) is a chronic vascular inflammatory disease, in which the lipid accumulation in the intima of the arteries shows yellow atheromatous appearance, which is the pathological basis of many diseases, such as coronary artery disease, peripheral artery disease and cerebrovascular disease. In recent years, it has become the main cause of death in the global aging society, which seriously endangers human health. As a result, research on AS is increasing. Lesions of atherosclerosis contain macrophages, T cells and other cells of the immune response, together with cholesterol that infiltrates from the blood. Recent studies have shown that chronic stress plays an important role in the occurrence and development of AS. From the etiology of disease, social, environmental and genetic factors jointly determine the occurrence of disease. Atherosclerotic cardio-cerebrovascular disease (ASCVD) is often caused by chronic stress (CS). If it cannot be effectively prevented, there will be biological changes in the body environment successively, and then the morphological changes of the corresponding organs. If the patient has a genetic predisposition and a combination of environmental factors triggers the pathogenesis, then chronic stress can eventually lead to AS. Therefore, this paper discusses the influence of chronic stress on AS in the aspects of inflammation, lipid metabolism, endothelial dysfunction, hemodynamics and blood pressure, plaque stability, autophagy, ferroptosis, and cholesterol efflux.

OUP accepted manuscript

Introduction

Cardiovascular diseases (CVDs) are the number one cause of death, and there is evidence that work exposures could be associated with their development. This study aimed to systematically review observational studies of adults exposed to job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise, and assess the association of those work exposures with CVDs.

Methods

The Navigation Guide framework was applied. The population were adults of working age (18–65), and cohort and case–control studies were included. The work exposures were job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise. The outcomes were cerebrovascular diseases, ischaemic heart disease, and hypertensive diseases. The selection, data extraction, risk of bias assessment, and quality assessment were carried out by two reviewers independently and disagreements were solved by a third reviewer or by consensus. The synthesis of the results was done by applying the ‘vote counting based on direction’ method, and the results were summarized in an effect direction plot. The strength of the evidence for every risk factor and CVD was defined by consensus.

Results

A total of 17 643 papers were initially identified in the literature search, but after applying the filters by title and abstract, and full text, 86 studies were finally included. From the included studies, sufficient evidence was found of the harmfulness of job strain for cerebrovascular disease and ischemic heart disease. Furthermore, there was sufficient evidence of the harmfulness of shift work for ischemic heart disease. Evidence of no relationship was found between long working hours and shift work with ischaemic heart disease and hypertensive disease, respectively. The other associations of work exposures and CVDs had limited or inadequate evidence of harmfulness.

Conclusions

In this comprehensive review, there was sufficient evidence of a harmful relationship between job strain, shift work, and CVDs. For the other work exposures, more high-quality studies are needed. In order to improve current prevention strategies for CVDs, the findings of this review imply that job strain and shift work are work exposures that constitute additional risk factors that could be approached as targets for worksite interventions.

Systematic review registration

PROSPERO CRD42020179972.

Job Dissatisfaction Mediated the Associations Between Work Stress and Mental Health Problems

Objective: This study aimed to explore the relationships and the underlying mechanisms between work stress and mental health problems, and potential mediation effects through job dissatisfaction in a working population. Methods: A large population-based study among workers in China was conducted. The self-reported scales of assessing job dissatisfaction and work stress were included in the questionnaire. Generalized Anxiety Disorder-2 and Patient Health Questionnaire-2 were used for assessment of mental health. Univariate logistic regression was conducted to test the associations between work stress and mental health. Path analysis was conducted to test the proposed mediation model. Results: Of the 6,190 included employees, 27.72% reported that they perceived work stress, 14.84% of them reported that they were not satisfied with their work, 5.01% of the employees reported depressive symptoms, and 3.75% of the employees reported anxiety symptoms. The results of univariate logistic regression showed that employees who perceived work stress were more likely to report anxiety symptoms (adjusted odds ratio (AOR) = 2.78; 95% CI: 2.03-3.79) or depressive symptoms (AOR = 1.61; 95% CI: 1.22-2.12). The path analysis showed that work stress was positively associated with job dissatisfaction. Job dissatisfaction mediated the relationship between work stress and mental health problems among Chinese working adults. Conclusion: This study suggests the importance of psychosocial work environment for mental health among Chinese working adults. Work dissatisfaction is a stressor that may induce negative consequences on the mental health among Chinese workers. Interventions to help workers with stress management may be beneficial for their mental health.

The effect of exposure to long working hours on alcohol consumption, risky drinking and alcohol use disorder: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing Joint Estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large network of experts. Evidence from mechanistic data suggests that exposure to long working hours may increase alcohol consumption and cause alcohol use disorder. In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from alcohol consumption and alcohol use disorder that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates.

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on alcohol consumption, risky drinking (three outcomes: prevalence, incidence and mortality) and alcohol use disorder (three outcomes: prevalence, incidence and mortality).

DATA SOURCES

We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic bibliographic databases for potentially relevant records from published and unpublished studies, including the WHO International Clinical Trials Register, Ovid MEDLINE, PubMed, Embase, and CISDOC on 30 June 2018. Searches on PubMed were updated on 18 April 2020. We also searched electronic grey literature databases, Internet search engines and organizational websites; hand-searched reference list of previous systematic reviews and included study records; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (<15 years) and unpaid domestic workers. We considered for inclusion randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on alcohol consumption (in g/week), risky drinking, and alcohol use disorder (prevalence, incidence or mortality).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from publications related to qualifying studies. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project.

RESULTS

Fourteen cohort studies met the inclusion criteria, comprising a total of 104,599 participants (52,107 females) in six countries of three WHO regions (Americas, South-East Asia, and Europe). The exposure and outcome were assessed with self-reported measures in most studies. Across included studies, risk of bias was generally probably high, with risk judged high or probably high for detection bias and missing data for alcohol consumption and risky drinking. Compared to working 35-40 h/week, exposure to working 41-48 h/week increased alcohol consumption by 10.4 g/week (95% confidence interval (CI) 5.59-15.20; seven studies; 25,904 participants, I2 71%, low quality evidence). Exposure to working 49-54 h/week increased alcohol consumption by 17.69 g/week (95% confidence interval (CI) 9.16-26.22; seven studies, 19,158 participants, I2 82%, low quality evidence). Exposure to working ≥55 h/week increased alcohol consumption by 16.29 g/week (95% confidence interval (CI) 7.93-24.65; seven studies; 19,692 participants; I2 82%, low quality evidence). We are uncertain about the effect of exposure to working 41-48 h/week, compared with working 35-40 h/week on developing risky drinking (relative risk 1.08; 95% CI 0.86-1.36; 12 studies; I2 52%, low certainty evidence). Working 49-54 h/week did not increase the risk of developing risky drinking (relative risk 1.12; 95% CI 0.90-1.39; 12 studies; 3832 participants; I2 24%, moderate certainty evidence), nor working ≥55 h/week (relative risk 1.11; 95% CI 0.95-1.30; 12 studies; 4525 participants; I2 0%, moderate certainty evidence). Subgroup analyses indicated that age may influence the association between long working hours and both alcohol consumption and risky drinking. We did not identify studies for which we had access to results on alcohol use disorder.

CONCLUSIONS

Overall, for alcohol consumption in g/week and for risky drinking, we judged this body of evidence to be of low certainty. Exposure to long working hours may have increased alcohol consumption, but we are uncertain about the effect on risky drinking. We found no eligible studies on the effect on alcohol use disorder. Producing estimates for the burden of alcohol use disorder attributable to exposure to long working hours appears to not be evidence-based at this time. PROTOCOL IDENTIFIER: https://doi.org/10.1016/j.envint.2018.07.025.

PROSPERO REGISTRATION NUMBER

CRD42018084077.

Job strain and the incidence of heart diseases: A prospective community study in Quebec, Canada

OBJECTIVE

Job strain (high psychological demands and low decision control) is associated with cardiovascular diseases, however it remains unclear if the associations are explained by depressive symptoms, and whether there are sex differences. The objective of the present study was to evaluate the association between job strain and heart diseases in a middle-aged population-based cohort.

METHODS

Baseline data were from CARTaGENE, a community survey of adults aged 40-60 years in Quebec, Canada. Incidence of heart diseases was examined in 8073 individuals by linking survey data with administrative data. Cox regression models were used to examine the association between job strain and heart disease, adjusting for sociodemographic characteristics, behavioral and clinical factors, and depressive symptoms.

RESULTS

In total, 557 (6.9%) participants developed heart diseases over an average follow-up of 6.6 years. Job strain was associated with an increased risk of heart diseases in women (adjusted HR = 1.63, 95% CI 1.02-2.64) after controlling for depressive symptoms, behavioral and clinical factors. There was no overall association between job strain and heart diseases in men (adjusted HR = 0.96, 95% CI 0.62-1.49); an association was observed only in men aged 50 years and older. Incidence of heart diseases and high job strain was highest in those with labour jobs, and lowest in those with professional jobs.

CONCLUSION

Job strain was associated with an increased risk of heart diseases in middle-aged women and in men aged 50 years and older. This association was not accounted for by depressive symptoms or sociodemographic, clinical, and behavioral factors.

The WHO/ILO report on long working hours and ischaemic heart disease - Conclusions are not supported by the evidence

Working hours is a ubiquitous exposure given that most adults are employed, and one that is modifiable via legislative change if not always through individual-level choice. According to a recent report from the World Health Organization (WHO) and International Labour Organization (ILO), there is currently sufficient evidence to conclude that long working hours (i.e., ≥55 h per week) elevate the risk of fatal and non-fatal ischaemic heart disease to a clinically meaningful extent. After assessing the data used by the ILO/WHO, we feel that the expert group has not correctly applied their own framework for assessing the strength of the evidence. In the meta-analysis of observational studies in the report, the association between long working hours and incident heart disease appeared stronger in lower quality cohort studies with a high risk of bias (minimally-adjusted hazard ratio 1.20, 95% CI 1.01-1.41, compared to standard 35-40 weekly hours) than in the superior-quality studies with a lower risk of bias for which the estimate was not significantly different from the null (1.08, 95% CI 0.93-1.25). There was also marked effect modification, such that there was no increase in ischaemic heart disease for those working long hours in high socioeconomic status occupations, a finding also reported in analyses of a recent census-based cohort study which was not included in the report. Our meta-analysis of all these studies confirm that the findings are not consistent but differ between subgroups and that the summary age- and sex-adjusted hazard ratio for long working hours in high socioeconomic status occupations does not support excess risk: 0.85, 95% CI 0.63-1.13 (P_interaction = 0.005, total N = 451,982). For these and other reasons detailed in this commentary, we advance a more cautious interpretation of the existing evidence. The conclusions should be restricted to low socioeconomic status occupations only and more research is still needed to confirm or refute harmfulness and determine clinical relevance.

The Impact of a Change in Employment on Three Work-Related Diseases: A Retrospective Longitudinal Study of 10,530 Belgian Employees

BACKGROUND

The literature that has investigated to what extent a change in employment contributes to good health is contradictory or shows inconsistent results. The aim of this study was to investigate whether an association exists between a change in employment and cardiovascular, musculoskeletal and neuropsychological diseases in a sample of 10,530 Belgian workers in a seven-year follow-up study period.

METHODS

The following factors were analysed: Demographic variables, a change in employment and the work-related risks. Individuals being on medication for cardiovascular, musculoskeletal, and neuropsychological diseases were used as proxies for the three health issues. Logistic regression models for autocorrelated data with repeated measures were used to examine each medication type.

RESULTS

A change in employment and psychosocial load can have an important effect on the health of cardiovascular employees. Demographic variables, such as BMI and age, are risk factors for all three medications. Repetitive, manual tasks, handling static, exposure to noise levels of 87 dB, mechanical and/or manual handling with loads, and shift work were found to be positively associated with medications taken for musculoskeletal diseases. Exposure to noise 80 dB(A), managing physical loads and night work were found to be associated with being on medication for neuropsychological diseases. Physical activity and skill levels were considered to be protective factors for being on medication for neuropsychological diseases.

CONCLUSIONS

Change in employment and psychosocial load were found as two important risk factors for being on medication for cardiovascular (CVD). Dealing with loads, doing shift work and being daily exposed to the noise of 87 dB correlated with being on medication for musculoskeletal (MSD). Dealing with physical loads, doing night work and being exposed to the noise of 80 dB were risk factors for being on medication for neuropsychological (NPD). While doing physical activity and reporting higher skill levels were found to be protective factors for NPD.

Long working hours and change in body weight: analysis of individual-participant data from 19 cohort studies

OBJECTIVE

To examine the relation between long working hours and change in body mass index (BMI).

METHODS

We performed random effects meta-analyses using individual-participant data from 19 cohort studies from Europe, US and Australia (n = 122,078), with a mean of 4.4-year follow-up. Working hours were measured at baseline and categorised as part time (<35 h/week), standard weekly hours (35-40 h, reference), 41-48 h, 49-54 h and ≥55 h/week (long working hours). There were four outcomes at follow-up: (1) overweight/obesity (BMI ≥ 25 kg/m2) or (2) overweight (BMI 25-29.9 kg/m2) among participants without overweight/obesity at baseline; (3) obesity (BMI ≥ 30 kg/m2) among participants with overweight at baseline, and (4) weight loss among participants with obesity at baseline.

RESULTS

Of the 61,143 participants without overweight/obesity at baseline, 20.2% had overweight/obesity at follow-up. Compared with standard weekly working hours, the age-, sex- and socioeconomic status-adjusted relative risk (RR) of overweight/obesity was 0.95 (95% CI 0.90-1.00) for part-time work, 1.07 (1.02-1.12) for 41-48 weekly working hours, 1.09 (1.03-1.16) for 49-54 h and 1.17 (1.08-1.27) for long working hours (P for trend <0.0001). The findings were similar after multivariable adjustment and in subgroup analyses. Long working hours were associated with an excess risk of shift from normal weight to overweight rather than from overweight to obesity. Long working hours were not associated with weight loss among participants with obesity.

CONCLUSIONS

This analysis of large individual-participant data suggests a small excess risk of overweight among the healthy-weight people who work long hours.

Gender assessment of job stress in healthcare workers. Implications for practice

Background:

Work-related stress (WRS) in the healthcare sector is a major issue for both workers and organizations. To date, no consensus exists regarding differences in gender susceptibility to WRS in healthcare workers (HCWs).

Objectives:

The purpose of this study was to analyze how male and female HCWs employed in emergency departments experienced WRS.

Methods:

A cross-sectional study was conducted regarding the perception of WRS in registered nurses employed in emergency departments. The Italian version of the Job Content Questionnaire and the Rapid Stress Assessment scale were administrated to 710 registered nurses.

Results:

The WRS assessment showed that significantly more females than males were in a situation of isostrain (18.5% vs 9.8% p<0,05). In females, low social support was associated with high levels of job strain (18,5% vs 4,4% p<0,05).

Conclusion:

This study reflects the need for a gender-specific approach in the evaluation of WRS in the healthcare sector, and is consistent with literature that evidenced gender differences in the perception of WRS. Lack of social support proved to be a determinant of WRS in female HCWs. Organizational interventions aimed at providing a more suitable workgroup design are required in order to minimize WRS in female HCWs.

Unique associations of the Job Demand-Control-Support model subscales with leisure-time physical activity and dietary energy intake

Leisure-time physical activity (LTPA) and dietary energy intake are two important health behaviours, which at too low or high levels respectively, are associated with overweight and obesity. This study explores associations between subscales of the Job Demand-Control-Support (JDCS) model, LTPA and dietary energy intake. A cross-sectional design sampled current employees (N=433) from a South Australian cohort using a computer-assisted telephone interview and a self-completed food frequency questionnaire. In analyses adjusted for sex, age, and sociodemographic variables, higher levels of skill discretion were associated with increased odds for attaining sufficient physical activity (OR=2.45; 95% CI=1.10-5.47). Higher levels of decision authority were associated with reduced odds (OR=0.43; 95% CI=0.20-0.93) for being in the highest tertile of daily energy intake. Higher scores for coworker support were associated with increased odds (OR=2.20; 95% CI=1.15-4.23) for being in the highest tertile of daily energy intake. These findings support the consideration of the individual JDCS subscales, since this practice may reveal novel associations with health behaviour outcomes, thereby presenting new opportunities to improve employee health and wellbeing.

Psychosocial stress impairs health behavior in patients with mental disorders

BACKGROUND

It has been shown, that in the general population psychosocial stress affects health behaviors. However similar studies of high risk populations are sparse. Therefore, the aim of this cross-sectional study is to analyze the association between common psychosocial stressors and health behavior in a sample of patients with mental disorders.

METHODS

We analyzed data of n = 2326 outpatients from a mental health care department. Severity of psychosocial stress was assessed by the PHQ-stress module of the Patient Health Questionnaire (PHQ). Health behaviors included obesity, uncontrolled eating, smoking and physical inactivity. Multiple binary regression models were conducted for the PHQ-stress score and for each of the ten PHQ-stress items as independent variables.

RESULTS

'Financial stress' and 'having no one to turn to with problems' were mainly associated with adverse health behaviors after adjustment for multivariate effects. The most affected health behaviors were uncontrolled eating in both sexes and obesity in women.

CONCLUSION

Our findings indicate specific influences of psychosocial stressors on unhealthy behaviors in a clinical sample. Patients with financial strain and lack of social support might need specific support for improving their health behavior.

Company size, work-home interference, and well-being of self-employed entrepreneurs

Background

The impact of working conditions on the health and well-being of workers of large enterprises has been widely described. This influence has not been studied as extensively in very small and medium-sized enterprises mainly due to methodological difficulties. Smaller organisations nevertheless constitute a reality that needs to be better understood.

Methodology

The aim of this article is to better understand the working conditions of entrepreneurs in small and medium-sized enterprises, to describe the impact of these conditions on their health and well-being, and to learn how their work affects their private lives.

This is why a study was conducted in 2015–2016 on a selected sample of entrepreneurs in the Brussels-Capital Region (n = 140). The survey form included questions pertaining to the work environment, motivations underlying the choice of activities, robustness of the business, work-home interference, work-related stress, work satisfaction, self-reported health indicators, and socio-demographic status. The results were compared with those from another survey on workers in small shops conducted between 2012 and 2015 within the same Region (n = 104).

Results

The number of entrepreneurs who participated in the survey added up to 140, with an even distribution between men and women. Two results are highlighted. The first concerns the difficulties faced by entrepreneurs working with a small team (1 to 4 employees): they are more stressed, report having heavy workloads, describe their health more negatively, consume more sedatives, and claim to suffer from loneliness more often than those working with larger teams or alone. Comparatively, in the study on shopkeepers, business owners working alone found themselves in a worse situation regarding their health and well-being.

The second finding involves the difficulties entrepreneurs face when it comes to combining work and family life, and for which gender inequalities were noted. This phenomenon remains insufficiently explored amongst small business owners.

Conclusion

In spite of the difficulties encountered at work, commitment to their chosen profession remains strong amongst entrepreneurs. Our results enable us underscore the aspects of entrepreneurial activity that should be taken into account whilst setting up support mechanisms or promoting entrepreneurship, especially amongst and for women.

Chronic Stress and Endothelial Dysfunction: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Endothelial dysfunction may represent an important link between chronic stress and cardiovascular disease (CVD) risk. However, few studies have examined the impact of chronic stress on endothelial dysfunction. The purpose of this study was to examine whether chronic stress was associated with flow-mediated dilation (FMD) and 2 biomarkers of endothelial dysfunction (intercellular adhesion molecule-1 (ICAM-1) and E-selectin) in a multiethnic sample of adults (ages 45-84 years).

METHODS

Data come from the baseline examination of Multi-Ethnic Study of Atherosclerosis participants. Chronic stress was assessed based on self-report of the presence and severity of ongoing problems in 5 domains. FMD was obtained using high-resolution ultrasound; biomarkers were assayed in different subsets of participants.

RESULTS

Higher chronic stress was associated with lower absolute FMD (mm FMD) in models adjusted for demographic and socioeconomic characteristics (0.169mm in high-stress participants vs. 0.178 and 0.179mm in medium and low-stress participants; P for trend = 0.04). This association remained unchanged with further adjustment for behavioral and biological CVD risk factors. Higher stress was related to higher ICAM-1 in models adjusted for sociodemographic characteristics and biological risk factors (P for trend = 0.005), but this association attenuated with adjustment for cigarette smoking (P for trend = 0.07). Chronic stress was not associated with E-selectin.

CONCLUSIONS

Our findings suggest chronic stress is related to endothelial dysfunction, possibly in part through other stress-associated CVD risk factors such as cigarette smoking.

Concealing Emotions at Work Is Associated with Allergic Rhinitis in Korea

Concealing emotions at work can cause considerable psychological stress. While there is extensive research on the adverse health effects of concealing emotions and the association between allergic diseases and stress, research has not yet investigated whether concealing emotions at work is associated with allergic rhinitis. Allergic rhinitis is a common disease in many industrialized countries, and its prevalence is increasing. Thus, our aim was to determine the strength of this association using data from three years (2007-2009) of the 4th Korean National Health and Nutrition Examination Survey. Participants (aged 20-64) were 8,345 individuals who were economically active and who had completed the questionnaire items on concealing emotions at work. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated for allergic rhinitis using logistic regression models. Among all participants, 3,140 subjects (37.6%) reported concealing their emotions at work: 1,661 men and 1,479 women. The OR (95% CIs) for allergic rhinitis among those who concealed emotions at work versus those who did not was 1.318 (1.148-1.512). Stratified by sex, the OR (95% CIs) was 1.307 (1.078-1.585) among men and 1.346 (1.105-1.639) among women. Thus, individuals who concealed their emotions at work were significantly more likely to have a diagnosis of AR in comparison to those who did not. Because concealing emotions at work has adverse health effects, labor policies that aim to reduce this practice are needed.

Reliability and Validity of Job Content Questionnaire in Chinese Petrochemical Employees

To evaluate psychometric properties the Chinese (mainland) version of the 30-item Job Content Questionnaire was administered to 889 employees in 4 industries of PetroChina. A retest at 3 months with 296 randomly chosen employees showed reliabilities ranged from .76 to .93. Cronbach coefficients alpha for the 8 dimensions ranged from .43 to .88, indicating that the Job Insecurity subscale had low internal consistency. Exploratory factor analysis showed 8 meaningful factors corresponding to the 8 theoretical dimensions of this questionnaire. This version has variable a but suitable retest to be a reliable and valid measure of job strain, applicable to the Chinese industrial working population of PetroChina.

Do psychosocial job resources buffer the relation between physical work demands and coronary heart disease? A prospective study among men

PURPOSE

Increasing evidence shows the detrimental impact of high physical work demands for cardiovascular health and mortality. The aim of this study was to investigate the buffering effects of social support at work and job control in the relation between physical work demands and incidence of coronary events.

METHODS

The study included 14,337 middle-aged men free from coronary heart disease (CHD) at baseline. The sample consisted of a mixed occupational group recruited within 18 organizations from the manufacturing, service, and public sector. Data were collected through standardized questionnaires and clinical examinations. The incidence of clinical coronary events was monitored during a mean follow-up time of 3.15 years. Multilevel Cox proportional hazard regression modeling was used, adjusting for socio-demographic and classical coronary risk factors.

RESULTS

Social support at work buffered the impact of physical work demands on CHD risk: Only among workers with low social support at work did physical work demands significantly increase the risk for CHD incidence (fully adjusted HR 2.50: 95 % CI 1.13-5.50), while this harmful effect completely disappeared in case of high level of workplace social support (fully adjusted HR 0.40; 95 % CI 0.09-1.70). No interaction or buffering effect with job control was observed.

CONCLUSIONS

The results of our study suggest that supportive relationships at work may be a useful resource for reducing the cardiovascular risk associated with physical work demands in men. Future studies are needed to confirm this moderating role of workplace social support and to unravel the underlying mechanisms.

The Boehringer Ingelheim employee study (Part 2): 10-year cardiovascular diseases risk estimation

BACKGROUND

Cardiovascular disease (CVD) may cause an economic burden to companies, but CVD risk estimations specific to working populations are lacking.

AIMS

To estimate the 10-year CVD risk in the Boehringer Ingelheim (BI) employee cohort and analyse the potential effect of hypothetical risk reduction interventions.

METHODS

We estimated CVD risk using the Framingham (FRS), PROCAM (PRS) and Reynolds (RRS) risk scores, using cross-sectional baseline data on BI Pharma employees collected from 2005 to 2011. Results were compared using Fisher's exact and Wilcoxon tests. The predictive ability of the score estimates was assessed using receiver-operating characteristics analyses.

RESULTS

Among the 4005 study subjects, we estimated 10-year CVD risks of 35% (FRS), 9% (PRS) and 6% (RRS) for men and 10% (FRS), 4% (PRS) and 1% (RRS) for women. One hundred and thirty-four (6%) men and 111 (6%) women employees had current CVD. The best predictors of prevalent CVD were the FRS and the RRS for men [area-under-the-curve 0.62 (0.57-0.67) for both]. A hypothetical intervention that would improve systolic blood pressure, HbA1c (for diabetes), C-reactive protein, triglycerides and total and high-density lipoprotein cholesterol by 10% each would potentially reduce expected CVD cases by 36-41% in men and 30-45% in women, and if smoking cessation is incorporated, by 39-45% and 30-55%, respectively, depending on the pre-intervention risk score.

CONCLUSIONS

There was a substantial risk of developing CVD in this working cohort. Occupational health programmes with lifestyle interventions for high-risk individuals may be an effective risk reduction measure.

Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603,838 individuals

BACKGROUND

Long working hours might increase the risk of cardiovascular disease, but prospective evidence is scarce, imprecise, and mostly limited to coronary heart disease. We aimed to assess long working hours as a risk factor for incident coronary heart disease and stroke.

METHODS

We identified published studies through a systematic review of PubMed and Embase from inception to Aug 20, 2014. We obtained unpublished data for 20 cohort studies from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium and open-access data archives. We used cumulative random-effects meta-analysis to combine effect estimates from published and unpublished data.

FINDINGS

We included 25 studies from 24 cohorts in Europe, the USA, and Australia. The meta-analysis of coronary heart disease comprised data for 603,838 men and women who were free from coronary heart disease at baseline; the meta-analysis of stroke comprised data for 528,908 men and women who were free from stroke at baseline. Follow-up for coronary heart disease was 5·1 million person-years (mean 8·5 years), in which 4768 events were recorded, and for stroke was 3·8 million person-years (mean 7·2 years), in which 1722 events were recorded. In cumulative meta-analysis adjusted for age, sex, and socioeconomic status, compared with standard hours (35-40 h per week), working long hours (≥55 h per week) was associated with an increase in risk of incident coronary heart disease (relative risk [RR] 1·13, 95% CI 1·02-1·26; p=0·02) and incident stroke (1·33, 1·11-1·61; p=0·002). The excess risk of stroke remained unchanged in analyses that addressed reverse causation, multivariable adjustments for other risk factors, and different methods of stroke ascertainment (range of RR estimates 1·30-1·42). We recorded a dose-response association for stroke, with RR estimates of 1·10 (95% CI 0·94-1·28; p=0·24) for 41-48 working hours, 1·27 (1·03-1·56; p=0·03) for 49-54 working hours, and 1·33 (1·11-1·61; p=0·002) for 55 working hours or more per week compared with standard working hours (ptrend<0·0001).

INTERPRETATION

Employees who work long hours have a higher risk of stroke than those working standard hours; the association with coronary heart disease is weaker. These findings suggest that more attention should be paid to the management of vascular risk factors in individuals who work long hours.

FUNDING

Medical Research Council, Economic and Social Research Council, European Union New and Emerging Risks in Occupational Safety and Health research programme, Finnish Work Environment Fund, Swedish Research Council for Working Life and Social Research, German Social Accident Insurance, Danish National Research Centre for the Working Environment, Academy of Finland, Ministry of Social Affairs and Employment (Netherlands), US National Institutes of Health, British Heart Foundation.

Association between job strain and risk of incident stroke: A meta-analysis

OBJECTIVE

Prospective cohort studies regarding job strain and the risk of stroke are controversial. This meta-analysis aimed to evaluate the association between job strain and the risk of stroke.

METHODS

The PubMed, Embase, and PsycINFO databases were searched for prospective cohort studies with data on job strain and the risk of stroke. Studies were included if they reported adjusted relative risks (RRs) with 95% confidence intervals (CIs) of stroke from job strain. Subgroup analyses were conducted according to sex and stroke type.

RESULTS

Six prospective cohort studies comprising 138,782 participants were included. High strain jobs were associated with increased risk of stroke (RR 1.22, 95% CI 1.01-1.47) compared with low strain jobs. The result was more pronounced for ischemic stroke (RR 1.58, 95% CI 1.12-2.23). The risk of stroke was significant in women (RR 1.33, 95% CI 1.04-1.69) and nonsignificant in men (RR 1.26, 95% CI 0.69-2.27), but the difference in RRs in sex subgroups was not significant. Neither active (RR 1.07, 95% CI 0.90-1.28) nor passive (RR 1.01, 95% CI 0.86-1.18) job characteristics were associated with an increased risk of stroke compared with low strain jobs.

CONCLUSIONS

Exposure to high strain jobs was associated with an increased risk of stroke, especially in women. Further studies are needed to confirm whether interventions to reduce work stress decrease the risk of stroke.

Long working hours and alcohol use: systematic review and meta-analysis of published studies and unpublished individual participant data

OBJECTIVE

To quantify the association between long working hours and alcohol use.

DESIGN

Systematic review and meta-analysis of published studies and unpublished individual participant data.

DATA SOURCES

A systematic search of PubMed and Embase databases in April 2014 for published studies, supplemented with manual searches. Unpublished individual participant data were obtained from 27 additional studies.

REVIEW METHODS

The search strategy was designed to retrieve cross sectional and prospective studies of the association between long working hours and alcohol use. Summary estimates were obtained with random effects meta-analysis. Sources of heterogeneity were examined with meta-regression.

RESULTS

Cross sectional analysis was based on 61 studies representing 333,693 participants from 14 countries. Prospective analysis was based on 20 studies representing 100,602 participants from nine countries. The pooled maximum adjusted odds ratio for the association between long working hours and alcohol use was 1.11 (95% confidence interval 1.05 to 1.18) in the cross sectional analysis of published and unpublished data. Odds ratio of new onset risky alcohol use was 1.12 (1.04 to 1.20) in the analysis of prospective published and unpublished data. In the 18 studies with individual participant data it was possible to assess the European Union Working Time Directive, which recommends an upper limit of 48 hours a week. Odds ratios of new onset risky alcohol use for those working 49-54 hours and ≥ 55 hours a week were 1.13 (1.02 to 1.26; adjusted difference in incidence 0.8 percentage points) and 1.12 (1.01 to 1.25; adjusted difference in incidence 0.7 percentage points), respectively, compared with working standard 35-40 hours (incidence of new onset risky alcohol use 6.2%). There was no difference in these associations between men and women or by age or socioeconomic groups, geographical regions, sample type (population based v occupational cohort), prevalence of risky alcohol use in the cohort, or sample attrition rate.

CONCLUSIONS

Individuals whose working hours exceed standard recommendations are more likely to increase their alcohol use to levels that pose a health risk.

The association between job strain and coronary heart disease: a meta-analysis of prospective cohort studies

BACKGROUND

Studies about work stress and the risk of coronary heart disease (CHD) have yielded inconsistent results. This meta-analysis aimed to investigate the association between job strain and the risk of CHD.

METHODS

We searched PubMed and Embase databases for studies reporting data on job strain and the risk of CHD. Studies were included if they reported multiple-adjusted relative risk (RR) with 95% confidence interval (CI) with respect to CHD from job strain.

RESULTS

Fourteen prospective cohort studies comprising 232,767 participants were included. The risk of CHD was increased in high-strain (RR 1.26; 95% CI 1.12-1.41) and passive jobs (RR 1.14; 95% CI 1.02-1.29) but not in active jobs (RR 1.09; 95% CI 0.97-1.22), when compared with low-strain group. The increased risk of CHD in high-strain and passive jobs was mainly driven by studies with a follow-up duration of ≥ 10 years. Neither the low-control (RR 1.06; 95% CI 0.93-1.19) nor high-demand (RR 1.13; 95% CI 0.97-1.32) dimension was independently associated with the risk of CHD.

CONCLUSIONS

Individuals with high-strain and passive jobs were more likely to experience a CHD event. Intervention programs incorporating individual and organizational levels are crucial for reducing job strain and the risk of CHD.

The association between concealing emotions at work and medical utilization in Korea

OBJECTIVES

We aimed to investigate the association between concealing emotions at work and medical utilization.

METHODS

Data from the 2007-2009 4th Korea National Health and Nutrition Examination Survey (KNHANES IV) was used, 7,094 participants (3,837 males, 3,257 females) aged between 20 and 54 who were economically active and completed all necessary questionnaire items were included. Odds ratios (ORs) and 95% confidence intervals (95% CI) for differences in hospitalization, outpatient visits, and pharmaceutical drug use between those who concealed their emotions and those who did not were investigated using logistic regression models with and without gender stratification.

RESULTS

Among those who concealed their emotions (n = 2,763), 47.4% were females, and 50.1% had chronic disease. In addition, 9.7% of the concealing emotions group had been hospitalized within the last year, 24.8% had been outpatients in the last two weeks, and 28.3% had used pharmaceutical drugs in the last two weeks. All ORs represent the odds of belonging to the concealing emotions group over the non-concealing emotions group. After adjustment for individual, occupational, socioeconomic and disease factors, the adjusted ORs (95% CI) in hospitalization are 1.29 (1.08 ~ 1.53) in the total population, 1.25 (0.98 ~ 1.60) in males and 1.30 (1.02 ~ 1.66) in females, in outpatient visits are 1.15 (1.02 ~ 1.29) in the total population, 1.05 (0.88 ~ 1.24) in males and 1.25 (1.06 ~ 1.47) in females and in pharmaceutical drug use are 1.12 (1.01 ~ 1.25) in the total population, 1.08 (0.92 ~ 1.27) in males and 1.14 (0.98 ~ 1.33) in females.

CONCLUSIONS

Those who concealed their emotions at work were more likely to use medical services. Moreover, the health effects of concealing emotions at work might be more detrimental in women than in men.

The annual costs of cardiovascular diseases and mental disorders attributable to job strain in France

BACKGROUND

Work stress has become a major occupational risk factor in industrialized countries and an important economic issue. The objective was to estimate the annual costs of coronary heart diseases (CHD) and mental disorders (MD) attributable to job strain exposure according to Karasek's model in France for the year 2003 from a societal perspective.

METHODS

We produced attributable fraction estimates which were applied to the number of cases (morbidity and mortality) and the costs of CHD and MD. Relative risk estimates came from a systematic literature review of prospective studies. We conducted meta-analyses based on this selection of studies. Prevalence of exposure to job strain came from the national SUMER survey conducted in France in 2003. Costs included direct medical costs and indirect costs: production losses due to sick leaves and premature deaths.

RESULTS

Between 8.8 and 10.2% of CHD morbidity was attributable to job strain, and between 9.4 and 11.2% of CHD mortality was attributable to this exposure for men. Between 15.2 and 19.8% of MD was attributable to job strain for men, and between 14.3 and 27.1% for women. As a whole, between 450 000 and 590 000 cases of diseases and 910-1130 deaths were attributable to job strain for men. From 730 000 to 1 380 000 cases of diseases and from 150 to 280 deaths were attributable to job strain for women. The total number of sick leave days amounted from 5 to 6.6 million days for men, and from 8.5 to 16 million days for women. The total costs of CHD and MD attributable to job strain exposure ranged from 1.8 to 3 billion euros for the year 2003 (0.12-0.19% GDP). Medical costs accounted for 11% of the total costs, value of life costs accounted for 13-15% and sick leave costs for 74-77%. The cost of CHD was estimated at 113-133 million euros and the cost of MD was between 1.7 - 2.8 billion euros in 2003.

CONCLUSION

This study on the economic burden of diseases attributable to job strain in France provides relevant insights for policy-makers when defining public health priorities for prevention policies.

Perceived job insecurity as a risk factor for incident coronary heart disease: systematic review and meta-analysis

OBJECTIVE

To determine the association between self reported job insecurity and incident coronary heart disease.

DESIGN

A meta-analysis combining individual level data from a collaborative consortium and published studies identified by a systematic review.

DATA SOURCES

We obtained individual level data from 13 cohort studies participating in the Individual-Participant-Data Meta-analysis in Working Populations Consortium. Four published prospective cohort studies were identified by searches of Medline (to August 2012) and Embase databases (to October 2012), supplemented by manual searches.

REVIEW METHODS

Prospective cohort studies that reported risk estimates for clinically verified incident coronary heart disease by the level of self reported job insecurity. Two independent reviewers extracted published data. Summary estimates of association were obtained using random effects models.

RESULTS

The literature search yielded four cohort studies. Together with 13 cohort studies with individual participant data, the meta-analysis comprised up to 174,438 participants with a mean follow-up of 9.7 years and 1892 incident cases of coronary heart disease. Age adjusted relative risk of high versus low job insecurity was 1.32 (95% confidence interval 1.09 to 1.59). The relative risk of job insecurity adjusted for sociodemographic and risk factors was 1.19 (1.00 to 1.42). There was no evidence of significant differences in this association by sex, age (<50 v ≥ 50 years), national unemployment rate, welfare regime, or job insecurity measure.

CONCLUSIONS

The modest association between perceived job insecurity and incident coronary heart disease is partly attributable to poorer socioeconomic circumstances and less favourable risk factor profiles among people with job insecurity.

Analysis of job stress in workers employed by three public organizations in Serbia

OBJECTIVES

The present study analyzes job stress in terms of education, age and the presence of cardiovascular and endocrine/metabolic diseases.

MATERIAL AND METHODS

A total of 411 workers employed by three public organizations completed the Job Content Questionnaire to classify their jobs based on the job strain model. Data about health condition, education and habits was obtained by the use of medical examinations and an interview.

RESULTS

The analysis of the completed Job Content Questionnaires indicates that workers with high education have significantly higher decision latitude (DL) than low-educated workers (one-way ANOVA, p < 0.0001). DL was also different between age groups (one-way ANOVA, p < 0.0001) - the highest DL values were observed in the oldest group, while the lowest DL mean was found in the youngest group. Psychological job demands (PJD) and social support (SS) were not significantly different between educational and age groups. The frequency of job stress categories was significantly different between low and highly-educated workers (χ(2) test, df = 3, p < 0.0001) and also between different age groups (χ(2) test, df = 6, p < 0.0001). The majority of highly-educated men were exposed to "active" jobs (high PJD and high DL). Most frequently, men older than 45 years experienced jobs with high DL ("active" and "low strain"), men aged 35 to 45 years were exposed to jobs with high PJD ("high strain" and "active") while the majority of men younger than 35 years were exposed to jobs with low DL ("high strain" and "passive"). No association between cardiovascular and endocrine/metabolic disorders and different job stress categories was observed.

CONCLUSION

"High strain" and "passive" jobs were most frequently identified among low-educated and young men. Despite the absence of association between job stress and cardiovascular and endocrine/metabolic diseases, we recommend prevention of work stress, particularly in the case of low-educated workers and workers younger than 45 years exposed to unfavorable job stress categories.

Job strain and cardiovascular disease risk factors: meta-analysis of individual-participant data from 47,000 men and women

BACKGROUND

Job strain is associated with an increased coronary heart disease risk, but few large-scale studies have examined the relationship of this psychosocial characteristic with the biological risk factors that potentially mediate the job strain - heart disease association.

METHODOLOGY AND PRINCIPAL FINDINGS

We pooled cross-sectional, individual-level data from eight studies comprising 47,045 participants to investigate the association between job strain and the following cardiovascular disease risk factors: diabetes, blood pressure, pulse pressure, lipid fractions, smoking, alcohol consumption, physical inactivity, obesity, and overall cardiovascular disease risk as indexed by the Framingham Risk Score. In age-, sex-, and socioeconomic status-adjusted analyses, compared to those without job strain, people with job strain were more likely to have diabetes (odds ratio 1.29; 95% CI: 1.11-1.51), to smoke (1.14; 1.08-1.20), to be physically inactive (1.34; 1.26-1.41), and to be obese (1.12; 1.04-1.20). The association between job strain and elevated Framingham risk score (1.13; 1.03-1.25) was attributable to the higher prevalence of diabetes, smoking and physical inactivity among those reporting job strain.

CONCLUSIONS

In this meta-analysis of work-related stress and cardiovascular disease risk factors, job strain was linked to adverse lifestyle and diabetes. No association was observed between job strain, clinic blood pressure or blood lipids.

Job strain and health-related lifestyle: findings from an individual-participant meta-analysis of 118,000 working adults

OBJECTIVES

We examined the associations of job strain, an indicator of work-related stress, with overall unhealthy and healthy lifestyles.

METHODS

We conducted a meta-analysis of individual-level data from 11 European studies (cross-sectional data: n = 118,701; longitudinal data: n = 43,971). We analyzed job strain as a set of binary (job strain vs no job strain) and categorical (high job strain, active job, passive job, and low job strain) variables. Factors used to define healthy and unhealthy lifestyles were body mass index, smoking, alcohol intake, and leisure-time physical activity.

RESULTS

Individuals with job strain were more likely than those with no job strain to have 4 unhealthy lifestyle factors (odds ratio [OR] = 1.25; 95% confidence interval [CI] = 1.12, 1.39) and less likely to have 4 healthy lifestyle factors (OR = 0.89; 95% CI = 0.80, 0.99). The odds of adopting a healthy lifestyle during study follow-up were lower among individuals with high job strain than among those with low job strain (OR = 0.88; 95% CI = 0.81, 0.96).

CONCLUSIONS

Work-related stress is associated with unhealthy lifestyles and the absence of stress is associated with healthy lifestyles, but longitudinal analyses suggest no straightforward cause-effect relationship between work-related stress and lifestyle.

Associations of job strain and lifestyle risk factors with risk of coronary artery disease: a meta-analysis of individual participant data

BACKGROUND

It is unclear whether a healthy lifestyle mitigates the adverse effects of job strain on coronary artery disease. We examined the associations of job strain and lifestyle risk factors with the risk of coronary artery disease.

METHODS

We pooled individual-level data from 7 cohort studies comprising 102 128 men and women who were free of existing coronary artery disease at baseline (1985-2000). Questionnaires were used to measure job strain (yes v. no) and 4 lifestyle risk factors: current smoking, physical inactivity, heavy drinking and obesity. We grouped participants into 3 lifestyle categories: healthy (no lifestyle risk factors), moderately unhealthy (1 risk factor) and unhealthy (2-4 risk factors). The primary outcome was incident coronary artery disease (defined as first nonfatal myocardial infarction or cardiac-related death).

RESULTS

There were 1086 incident events in 743,948 person-years at risk during a mean follow-up of 7.3 years. The risk of coronary artery disease among people who had an unhealthy lifestyle compared with those who had a healthy lifestyle (hazard ratio [HR] 2.55, 95% confidence interval [CI] 2.18-2.98; population attributable risk 26.4%) was higher than the risk among participants who had job strain compared with those who had no job strain (HR 1.25, 95% CI 1.06-1.47; population attributable risk 3.8%). The 10-year incidence of coronary artery disease among participants with job strain and a healthy lifestyle (14.7 per 1000) was 53% lower than the incidence among those with job strain and an unhealthy lifestyle (31.2 per 1000).

INTERPRETATION

The risk of coronary artery disease was highest among participants who reported job strain and an unhealthy lifestyle; those with job strain and a healthy lifestyle had half the rate of disease. A healthy lifestyle may substantially reduce disease risk among people with job strain.

The prospective relationship between work stressors and cardiovascular disease, using a comprehensive work stressor measure for exposure assessment

PURPOSE

The currently used instruments which measure the psychosocial work environment have been criticized. We analyzed the association between work stressors and cardiovascular disease, using the Maastricht Cohort Study Work Stressor Score (MCS-WSS), a comprehensive measure which has been associated with work strain.

METHODS

At baseline 11,489 employees of the Maastricht Cohort Study were participating. This prospective cohort study started in 1998 in the Netherlands and includes a heterogeneous population of employees. The psychosocial work environment, cardiovascular risk factors and the occurrence of cardiovascular disease were measured with questionnaires at various time points during follow-up, the last follow-up was in 2008. For a subsample of employees, CVD extracted from medical records was available. The MCS-WSS consists of items from emotional demands, psychological demands, role clarity, career possibilities, working overtime, job insecurity, cognitive demands, skills discretion and decision authority. Each item has its own contribution in inducing work strain, represented by its own weighting factor. The association between a high exposure to work stressors at baseline and cardiovascular morbidity was assessed with Cox regression analyses. Analyses were adjusted for age, gender, educational level, smoking, body mass index, alcohol consumption and leisure physical activity.

RESULTS

During a median follow-up of 49 months, 309 employees developed incident cardiovascular disease. Overall, no significant associations were found between a high exposure to work stressors at baseline and cardiovascular morbidity.

CONCLUSIONS

The results of this study indicate that high exposure to work stressors has no considerable impact on cardiovascular disease.

The association between leisure time physical activity and coronary heart disease among men with different physical work demands: a prospective cohort study

The interplay of occupational and leisure time physical activity (LTPA) in affecting cardiovascular health is subject to debate. This study aimed to examine the independent and interacting associations of leisure time and occupational physical activity (OPA) with the incidence of coronary events within the BELSTRESS cohort. The study included 14,337 middle-aged men free from coronary heart disease at baseline. Standardized questionnaires and clinical examinations were used to assess socio-demographic factors, level of physical activity, job strain and classical coronary risk factors. The incidence of clinical coronary events was monitored during a mean follow-up time of 3.15 years. Results demonstrated overall a beneficial relation of LTPA and an adverse relation of physical work demands with cardiovascular health. However, an interaction effect between both physical activity types was observed, showing that men with high physical job demands who also engaged in physical activity during leisure time had an almost four times increased incidence of coronary events after adjusting for socio-demographic and classical coronary risk factors (HR 3.82; 95% CI 1.41-10.36). Stratified analyses revealed that moderate to high physical activity during leisure time was associated with a 60% reduced incidence rate of coronary events in men with low OPA (age adjusted HR 0.40; 95% CI 0.21-0.76), while this protective association was not observed in workers being exposed to high physical work demands (age adjusted HR 1.67; 95% CI 0.63-4.48). These findings suggest that recommendations regarding LTPA should be tailored according to the level of occupational physical activity.

Job strain as a risk factor for coronary heart disease: a collaborative meta-analysis of individual participant data

BACKGROUND

Published work assessing psychosocial stress (job strain) as a risk factor for coronary heart disease is inconsistent and subject to publication bias and reverse causation bias. We analysed the relation between job strain and coronary heart disease with a meta-analysis of published and unpublished studies.

METHODS

We used individual records from 13 European cohort studies (1985-2006) of men and women without coronary heart disease who were employed at time of baseline assessment. We measured job strain with questions from validated job-content and demand-control questionnaires. We extracted data in two stages such that acquisition and harmonisation of job strain measure and covariables occurred before linkage to records for coronary heart disease. We defined incident coronary heart disease as the first non-fatal myocardial infarction or coronary death.

FINDINGS

30,214 (15%) of 197,473 participants reported job strain. In 1·49 million person-years at risk (mean follow-up 7·5 years [SD 1·7]), we recorded 2358 events of incident coronary heart disease. After adjustment for sex and age, the hazard ratio for job strain versus no job strain was 1·23 (95% CI 1·10-1·37). This effect estimate was higher in published (1·43, 1·15-1·77) than unpublished (1·16, 1·02-1·32) studies. Hazard ratios were likewise raised in analyses addressing reverse causality by exclusion of events of coronary heart disease that occurred in the first 3 years (1·31, 1·15-1·48) and 5 years (1·30, 1·13-1·50) of follow-up. We noted an association between job strain and coronary heart disease for sex, age groups, socioeconomic strata, and region, and after adjustments for socioeconomic status, and lifestyle and conventional risk factors. The population attributable risk for job strain was 3·4%.

INTERPRETATION

Our findings suggest that prevention of workplace stress might decrease disease incidence; however, this strategy would have a much smaller effect than would tackling of standard risk factors, such as smoking.

FUNDING

Finnish Work Environment Fund, the Academy of Finland, the Swedish Research Council for Working Life and Social Research, the German Social Accident Insurance, the Danish National Research Centre for the Working Environment, the BUPA Foundation, the Ministry of Social Affairs and Employment, the Medical Research Council, the Wellcome Trust, and the US National Institutes of Health.

Job strain, job insecurity, and incident cardiovascular disease in the Women's Health Study: results from a 10-year prospective study

OBJECTIVES

Research about work-related stressors and cardiovascular disease (CVD) has produced mixed findings. Moreover, a paucity of data exists regarding the long-term associations between job strain and job insecurity and CVD among women.

METHODS

We used Cox proportional hazard models to examine the relationship between job strain, job insecurity, and incident CVD over 10 years of follow-up among 22,086 participants in the Women's Health Study (mean age 57±5 years).

RESULTS

During 10 years of follow-up there were 170 myocardial infarctions (MI), 163 ischemic strokes, 440 coronary revascularizations, and 52 CVD deaths. In models adjusted for age, race, education, and income, women with high job strain (high demand, low control) were 38% more likely to experience a CVD event than their counterparts who reported low job strain (low demand, high control; Rate Ratio (RR) = 1.38, 95% Confidence Interval (CI) = 1.08-1.77), and women with active jobs (high demand, high control) were 38% more likely to experience a CVD event relative to women who reported low job strain (95% CI = 1.07-1.77). Outcome-specific analyses revealed that high job strain predicted non-fatal myocardial infarction (RR = 1.67, CI = 1.04-2.70), and coronary revascularization (RR = 1.41, CI = 1.05-1.90). No evidence of an association between job insecurity and long-term CVD risk was observed.

CONCLUSION

High strain and active jobs, but not job insecurity, were related to increased CVD risk among women. Both job strain and job insecurity were significantly related to CVD risk factors. With the increase of women in the workforce, these data emphasize the importance of addressing job strain in CVD prevention efforts among working women.

The effects of shift work on physical and mental health

Occupational engagement is a pre-requisite for continuous income opportunities. Among the changing social circumstances work-related conditions play an increasingly eminent role in psychological and mental well-being. The public discusses the question of a possible association between the demands of modern work life and the increases of psychological, psychosomatic and cardiovascular disorders. Given the socioeconomic implications of psychiatric and psychosomatic suffering in the general population, there is a need to further elucidate the causes of their increasing incidence. From a medical point of view, any organization of work disrupting the phased circadian rhythms for bio-psycho-social processes and functioning of the individual are interesting against the background of clock genes and certain biological functions that are organized in a circadian fashion. The authors review the influence of shift work as a form of systematic desynchronization of inner clock systems on the endocrine, the physical, and the mental level. The significance of the findings in the field is discussed along with future directions of conclusive research.

Stress and cardiovascular disease

The physiological reaction to psychological stress, involving the hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullary axes, is well characterized, but its link to cardiovascular disease risk is not well understood. Epidemiological data show that chronic stress predicts the occurrence of coronary heart disease (CHD). Employees who experience work-related stress and individuals who are socially isolated or lonely have an increased risk of a first CHD event. In addition, short-term emotional stress can act as a trigger of cardiac events among individuals with advanced atherosclerosis. A stress-specific coronary syndrome, known as transient left ventricular apical ballooning cardiomyopathy or stress (Takotsubo) cardiomyopathy, also exists. Among patients with CHD, acute psychological stress has been shown to induce transient myocardial ischemia and long-term stress can increase the risk of recurrent CHD events and mortality. Applications of the 'stress concept' (the understanding of stress as a risk factor and the use of stress management) in the clinical settings have been relatively limited, although the importance of stress management is highlighted in European guidelines for cardiovascular disease prevention.

Differential associations of job control components with mortality: a cohort study, 1986-2005

Inconsistent evidence of the hypothesized favorable effects of high job control on health may have resulted from a failure to treat job control as a multifactor concept. The authors studied whether the 2 components of job control, decision authority and skill discretion, were differentially associated with cause-specific mortality in 13,510 Finnish forest company employees with no history of severe illness. Surveys on work characteristics were carried out in 1986 and 1996, and the respondents were followed up until the end of 2005 by use of the Statistics Finland National Death Registry. During a mean follow-up of 15.5 years, 981 participants died. In the analyses adjusted for confounders, employees with high and intermediate levels of skill discretion had a lower all-cause mortality risk than those with low skill discretion, with hazard ratios of 0.84 (95% confidence interval (CI): 0.69, 1.02) and 0.81 (95% CI: 0.69, 0.96), respectively. In contrast, high decision authority was associated with elevated risks of all-cause, cardiovascular, and alcohol-related mortality, with hazard ratios of 1.28 (95% CI: 1.06, 1.54), 1.49 (95% CI: 1.11, 2.02), and 2.03 (95% CI: 1.03, 4.00), respectively. The results suggest that job control is not an unequivocal concept in relation to mortality; decision authority and skill discretion show different and to some extent opposite associations.

Frequency and related factors of masked hypertension at a worksite in Korea

Objectives

Masked hypertension is associated with metabolic risks and increased risk of cardiovascular disease. The purpose of this study was to identify the frequency of and risk factors of masked hypertension in Korean workers.

Methods

The study was conducted among 121 employees at a hotel in Gyeongju, Korea, from December 2008 to February 2009. We measured blood pressure (BP) both in the clinic and using 24-hour ambulatory BP monitors for all subjects. Hypertension was defined independently by both methods, and subjects were classified into four groups: true normotension, masked hypertension, white coat hypertension, and sustained hypertension.

Results

The frequency of masked hypertension in our study group was 25.6%. Compared with true normotension, the factors related to masked hypertension were male gender (odds ratio [OR], 10.7; 95% confidence interval [CI], 1.41 to 81.09), aging one year (OR, 0.88; 95% CI, 0.78 to 0.99), clinic BP 120-129/80-84 mmHg (OR, 8.42; 95% CI, 1.51 to 46.82), clinic BP 130-139 / 85-89 mmHg (OR, 12.14; 95% CI, 1.80 to 81.85), smoking (OR, 5.51; 95% CI, 1.15 to 26.54), and increase of total cholesterol 1 mg / dL (OR, 1.05; 95% CI, 1.02 to 1.08). In males only, these factors were clinic BP 120-129 / 80-84 mmHg (OR, 15.07; 95% CI, 1.55 to 146.19), clinic BP 130-139 / 85-89 mmHg (OR, 17.16; 95% CI, 1.56 to 189.45), smoking (OR, 11.61; 95% CI, 1.52 to 88.62), and increase of total cholesterol 1 mg/dL (OR, 1.05; 95% CI, 1.01 to 1.09).

Conclusions

The frequency of masked hypertension was high in our study sample. Detection and management of masked hypertension, a known strong predictor of cardiovascular risk, could improve prognosis for at-risk populations.

A prospective cohort study of neighborhood stress and ischemic heart disease in Japan: a multilevel analysis using the JACC study data

BACKGROUND

A body of research has shown that neighborhood environment may have an effect on a variety of health outcomes, including cardiovascular disease. One explanation for the mechanism of the effect of neighborhood on cardiovascular disease is psychosocial pathways. Direct evidence for an effect of neighborhood on cardiovascular disease with adjustment for perceived stress at the individual level has not been obtained, however. The Japan Collaborative Cohort Study for the Evaluation of Cancer Risk provides a unique dataset which has aggregated area-based cohorts from 45 areas throughout Japan. The purpose of the present study was to examine the contextual effect of area-level stress on ischemic heart disease using data from a large prospective cohort in Japan.

METHODS

A baseline survey of 110,792 residents of 45 areas aged 40-79 years was conducted between 1988 and 1990. Analysis was restricted to subjects from the 33 of 45 areas providing information about self-rated stress (32183 men and 45896 women). Multilevel Poisson regression models were employed in a two-level structure of individuals nested within the 33 areas. Area-level stress was calculated by sex as the number of persons who rated their stress level as high divided by the total number of subjects in that area. Mortality rate ratios (MRRs) per 1 percentage point increase in area-level stress were estimated with adjustment for compositional individual factors.

RESULTS

During 15 years of follow-up (1,116,895 person-years), 936 deaths due to ischemic heart disease were recorded. Area-level stress varied from 6% to 22%. In the multivariable models, MRRs of area-level stress were 1.06 (95% confidence interval: 1.00-1.12, p = 0.043) in men and 1.07 (95% confidence interval: 1.00-1.14, p = 0.057) in women.

CONCLUSIONS

Area-level stress affects the likelihood of death due to ischemic heart disease of individuals in men. The present findings may suggest that stress should be considered not only within the individual but also within the neighborhood context.

The role of psychosocial stress at work for the development of cardiovascular diseases: a systematic review

PURPOSE

A systematic review was carried out to assess evidence for the association between different models of stress at work, and cardiovascular morbidity and mortality.

METHODS

A literature search was conducted using five databases (MEDLINE, Cochrane Library, EMBASE, PSYNDEX and PsycINFO). Inclusion criteria for studies were the following: self-reported stress for individual workplaces, prospective study design and incident disease (myocardial infarction, stroke, angina pectoris, high blood pressure). Evaluation, according to the criteria of the Scottish Intercollegiate Guidelines Network, was done by two readers. In case of disagreement, a third reader was involved.

RESULTS

Twenty-six publications were included, describing 40 analyses out of 20 cohorts. The risk estimates for work stress were associated with a statistically significant increased risk of cardiovascular disease in 13 out of the 20 cohorts. Associations were significant for 7 out of 13 cohorts applying the demand-control model, all three cohorts using the effort-reward model and 3 out of 6 cohorts investigating other models. Most significant results came from analyses considering only men. Results for the association between job stress and cardiovascular diseases in women were not clear. Associations were weaker in participants above the age of 55.

CONCLUSIONS

In accordance with other systematic reviews, this review stresses the importance of psychosocial factors at work in the aetiology of cardiovascular diseases. Besides individual measures to manage stress and to cope with demanding work situations, organisational changes at the workplace need to be considered to find options to reduce occupational risk factors for cardiovascular diseases.

Does adding information on job strain improve risk prediction for coronary heart disease beyond the standard Framingham risk score? The Whitehall II study

BACKGROUND

Guidelines for coronary heart disease (CHD) prevention recommend using multifactorial risk prediction algorithms, particularly the Framingham risk score. We sought to examine whether adding information on job strain to the Framingham model improves its predictive power in a low-risk working population.

METHODS

Our analyses are based on data from the prospective Whitehall II cohort study, UK. Job strain among 5533 adults (mean age 48.9 years, 1666 women) was ascertained in Phases 1 (1985-88), 2 (1989-90) and 3 (1991-93). Variables comprising the Framingham score (blood lipids, blood pressure, diabetes and smoking) were measured at Phase 3. In men and women who were CHD free at baseline, CHD mortality and non-fatal myocardial infarction (MI) were ascertained from 5-yearly screenings and linkage to mortality and hospital records until Phase 7 (2002-04).

RESULTS

A total of 160 coronary deaths and non-fatal MIs occurred during the mean follow-up period of 11.3 years. The addition of indicators of job strain to the Framingham score increased the C-statistics from 0.725 [95% confidence intervals (95% CIs): 0.575-0.854] to only 0.726 (0.577-0.855), corresponding to a net reclassification improvement of 0.7% (95% CIs: -4.2 to 5.6%). The findings were similar after inclusion of definite angina in the CHD outcome (352 total cases) and when using alternative operational definitions for job strain.

CONCLUSION

In this middle-aged low-risk working population, job strain was associated with an increased risk of CHD. However, when compared with the Framingham algorithm, adding job strain did not improve the model's predictive performance.

The Magnitude of Mortality from Ischemic Heart Disease Attributed to Occupational Factors in Korea - Attributable Fraction Estimation Using Meta-analysis

Objectives

Ischemic heart disease (IHD) is a major cause of death in Korea and known to result from several occupational factors. This study attempted to estimate the current magnitude of IHD mortality due to occupational factors in Korea.

Methods

After selecting occupational risk factors by literature investigation, we calculated attributable fractions (AFs) from relative risks and exposure data for each factor. Relative risks were estimated using meta-analysis based on published research. Exposure data were collected from the 2006 Survey of Korean Working Conditions. Finally, we estimated 2006 occupation-related IHD mortality.

Results

For the factors considered, we estimated the following relative risks: noise 1.06, environmental tobacco smoke 1.19 (men) and 1.22 (women), shift work 1.12, and low job control 1.15 (men) and 1.08 (women). Combined AFs of those factors in the IHD were estimated at 9.29% (0.3-18.51%) in men and 5.78% (-7.05-19.15%) in women. Based on these fractions, Korea's 2006 death toll from occupational IHD between the age of 15 and 69 was calculated at 353 in men (total 3,804) and 72 in women (total 1,246).

Conclusion

We estimated occupational IHD mortality of Korea with updated data and more relevant evidence. Despite the efforts to obtain reliable estimates, there were many assumptions and limitations that must be overcome. Future research based on more precise design and reliable evidence is required for more accurate estimates.