Work stress and loss of years lived without chronic disease: an 18-year follow-up of 1.5 million employees in Denmark.

We aimed to examine the association between exposure to work stress and chronic disease incidence and loss of chronic disease-free life years in the Danish workforce. The study population included 1,592,491 employees, aged 30-59 in 2000 and without prevalent chronic diseases. We assessed work stress as the combination of job strain and effort-reward imbalance using job exposure matrices. We used Cox regressions to estimate risk of incident hospital-diagnoses or death of chronic diseases (i.e., type 2 diabetes, coronary heart disease, stroke, cancer, asthma, chronic obstructive pulmonary disease, heart failure, and dementia) during 18 years of follow-up and calculated corresponding chronic disease-free life expectancy from age 30 to age 75. Individuals working in occupations with high prevalence of work stress had a higher risk of incident chronic disease compared to those in occupations with low prevalence of work stress (women: HR 1.04 (95% CI 1.02-1.05), men: HR 1.12 (95% CI 1.11-1.14)). The corresponding loss in chronic disease-free life expectancy was 0.25 (95% CI - 0.10 to 0.60) and 0.84 (95% CI 0.56-1.11) years in women and men, respectively. Additional adjustment for health behaviours attenuated these associations among men. We conclude that men working in high-stress occupations have a small loss of years lived without chronic disease compared to men working in low-stress occupations. This finding appeared to be partially attributable to harmful health behaviours. In women, high work stress indicated a very small and statistically non-significant loss of years lived without chronic disease.

Commuting distance and behavior-related health: A longitudinal study.

Health benefits of active commuting and short commuting time are well-documented; however, limited evidence exists on the effects of commuting distance. We examined longitudinal associations between commuting distance and behavior-related health. Participants were from four survey waves of the Swedish Longitudinal Occupational Survey of Health (2012, 2014, 2016, and 2018). Analytical sample included 11,023 individuals and 21,769 observations. Random effects method used binomial logistic regression with generalized estimating equations. The outcomes were self-reported physical inactivity, overweight, smoking, problem drinking, and disturbed sleep. Models were adjusted for age, sex, occupational position, civil status, chronic disease, work strain, number of children under 12, and home/workplace neighborhood socioeconomic status. Using continuous measure, long commuting distance was associated with a higher odds of physical inactivity (OR 1.06; 95% CI, 1.04-1.09 per doubling of distance), overweight (OR 1.02; 95% CI, 1.00-1.04), and disturbed sleep (OR 1.03; 95% CI, 1.00-1.05) in fully adjusted models. Using categorized measure, individuals who commuted longer distance had a higher odds of physical inactivity compared to those with the shortest commute (3.1 km - <7.9 km vs. <3.1 km: OR 1.15; 95% CI, 1.04-1.28 and 7.9 km - <20 km vs. <3.1 km: OR 1.18; 95% CI, 1.06-1.32, fully adjusted model). Such dose-response associations were not observed for overweight or disturbed sleep. Our results suggest short commuting distance may be beneficial for behavior-related health.

Home and Workplace Neighborhood Socioeconomic Status and Behavior-related Health: A Within-individual Analysis.

BACKGROUND: The influence of individual and home neighborhood socioeconomic status (SES) on health-related behaviors have been widely studied, but the majority of these studies have neglected the possible impact of the workplace neighborhood SES. OBJECTIVE: To examine within-individual associations between home and work place neighborhood SES and health-related behaviors in employed individuals. METHODS: We used participants from the Swedish Longitudinal Occupational Survey of Health who responded to a minimum of two surveys between 2012 and 2018. Data included 12,932 individuals with a total of 35,332 observations. We used fixed-effects analysis with conditional logistic regression to examine within-individual associations of home, workplace, as well as time-weighted home and workplace neighborhood SES index, with self-reported obesity, physical activity, smoking, excessive alcohol consumption, sedentary lifestyle, and disturbed sleep. RESULTS: After adjustment for covariates, participants were more likely to engage in risky alcohol consumption when they worked in a workplace that was located in the highest SES area compared to time when they worked in a workplace that was located in the lowest SES area (adjusted odds ratios 1.98; 95% confidence interval: 1.12 to 3.49). There was an indication of an increased risk of obesity when individuals worked in the highest compared to the time when they worked in the lowest neighborhood SES area (1.71; 1.02-2.87). No associations were observed for the other outcomes. CONCLUSION: These within-individual comparisons suggest that workplace neighborhood SES might have a role in health-related behaviors, particularly alcohol consumption.

Psychosocial job strain and polypharmacy: a national cohort study.

Objectives Psychosocial job strain has been associated with a range of adverse health outcomes. The aim of this study was to examine the association between psychosocial job strain and prospective risk of polypharmacy (the prescription of ≥5 medications) and to evaluate whether coping strategies can modify this risk. Methods Cohort study of 9703 working adults [mean age 47.5 (SD 10.8) years; 54% female] who participated in the Swedish Longitudinal Occupational Survey of Health (SLOSH) at baseline in 2006 or 2008. Psychosocial job strain was represented by job demands and control, and measured by the Swedish version of the demand-control questionnaire. The outcome was incidence of polypharmacy over an eight-year follow-up period. Information on dispensed drugs were extracted from the Swedish Prescribed Drug Register. Logistic regression was used to estimate the association of job strain status with polypharmacy, adjusted for a range of confounders. Results During the follow-up, 1409 people developed polypharmacy (incident rate: 20.6/1000 person-years). In comparison to workers with low-strain jobs (high control/low demands), those with high-strain jobs (low control/high demands) had a significantly higher risk of incident polypharmacy (OR 1.40, 95% CI 1.04-1.89). The impact of high-strain jobs on developing polypharmacy remained among those with covert coping strategies (ie, directed inwards or towards others) but not among those with open coping strategies (ie, primarily directed toward the stressor). Conclusions Workers in high-strain jobs may be at an increased risk of polypharmacy. Open coping strategies may reduce the negative impact of psychosocial job strain on risk of polypharmacy.

Job insecurity and risk of coronary heart disease: Mediation analyses of health behaviors, sleep problems, physiological and psychological factors.

Job insecurity has been linked to increased risk of coronary heart disease (CHD), but underlying mechanisms remain uncertain. Our aim was to assess the extent to which this association is mediated through life style, physiological, or psychological factors. A total of 3917 men and women free from CHD provided data on job insecurity in the Whitehall II cohort study in 1997-1999. The association between job insecurity and CHD was decomposed into a direct and indirect effect mediated through unhealthy behaviors (smoking, high alcohol consumption, physical inactivity), sleep disturbances, 'allostatic load', or psychological distress. The counterfactual analyses on psychological distress indicated a marginally significant association between job insecurity and incident CHD (hazard ratio (HR) 1.32; 95 % confidence interval (CI) 1.00-1.75). This association was decomposed into a direct (HR 1.22, 95 %CI 0.92-1.63) and indirect association (1.08, 95 %CI 1.01-1.15), suggesting that about 30 % of the total relationship was mediated by psychological distress. No mediation was indicated via health behaviors, sleep disturbances, or allostatic load, although job insecurity was related to disturbed sleep and C-reactive protein, which, in turn were associated with CHD. In conclusion, our results suggest that psychological distress may play a role in the relation between job insecurity and CHD.

Job Strain as a Risk Factor for Peripheral Artery Disease: A Multi-Cohort Study.

Background Job strain is implicated in many atherosclerotic diseases, but its role in peripheral artery disease (PAD) is unclear. We investigated the association of job strain with hospital records of PAD, using individual-level data from 11 prospective cohort studies from Finland, Sweden, Denmark, and the United Kingdom. Methods and Results Job strain (high demands and low control at work) was self-reported at baseline (1985-2008). PAD records were ascertained from national hospitalization data. We used Cox regression to examine the associations of job strain with PAD in each study, and combined the study-specific estimates in random effects meta-analyses. We used τ2, I2, and subgroup analyses to examine heterogeneity. Of the 139 132 participants with no previous hospitalization with PAD, 32 489 (23.4%) reported job strain at baseline. During 1 718 132 person-years at risk (mean follow-up 12.8 years), 667 individuals had a hospital record of PAD (3.88 per 10 000 person-years). Job strain was associated with a 1.41-fold (95% CI, 1.11-1.80) increased average risk of hospitalization with PAD. The study-specific estimates were moderately heterogeneous (τ2=0.0427, I2: 26.9%). Despite variation in their magnitude, the estimates were consistent in both sexes, across the socioeconomic hierarchy and by baseline smoking status. Additional adjustment for baseline diabetes mellitus did not change the direction or magnitude of the observed associations. Conclusions Job strain was associated with small but consistent increase in the risk of hospitalization with PAD, with the relative risks on par with those for coronary heart disease and ischemic stroke.

Risk and Prognostic Factors of Low Back Pain: Repeated Population-based Cohort Study in Sweden.

STUDY DESIGN: Prospective longitudinal cohort study. OBJECTIVE: To determine the associations for workload and health-related factors with incident and recurrent low back pain (LBP), and to determine the mediating role of health-related factors in associations between physical workload factors and incident LBP. SUMMARY OF BACKGROUND DATA: It is not known whether the risk factors for the development of LBP are also prognostic factors for recurrence of LBP and whether the associations between physical workload and incident LBP are mediated by health-related factors. We used data from the Swedish Longitudinal Occupational Survey of Health study. Those responding to any two subsequent surveys in 2010 to 2016 were included for the main analyses (N = 17,962). Information on occupational lifting, working in twisted positions, weight/height, smoking, physical activity, depressive symptoms, and sleep problems were self-reported. Incident LBP was defined as pain limiting daily activities in the preceding three months in participants free from LBP at baseline. Recurrent LBP was defined as having LBP both at baseline and follow-up. For the mediation analyses, those responding to three subsequent surveys were included (N = 3516). METHODS: Main associations were determined using generalized estimating equation models for repeated measures data. Mediation was examined with counterfactual mediation analysis. RESULTS: All risk factors at baseline but smoking and physical activity were associated with incident LBP after adjustment for confounders. The strongest associations were observed for working in twisted positions (risk ratio  = 1.52, 95% CI 1.37, 1.70) and occupational lifting (risk ratio  = 1.52, 95% CI 1.32, 1.74). These associations were not mediated by health-related factors. The studied factors did not have meaningful effects on recurrent LBP. CONCLUSION: The findings suggest that workload and health-related factors have stronger effects on the development than on the recurrence or progression of LBP, and that health-related factors do not mediate associations between workload factors and incident LBP. LEVEL OF EVIDENCE: 3.

Does inflammation provide a link between psychosocial work characteristics and diabetes? Analysis of the role of interleukin-6 and C-reactive protein in the Whitehall II cohort study.

OBJECTIVE: Inflammation may underlie the association between psychological stress and cardiometabolic diseases, but this proposition has not been tested longitudinally. We investigated whether the circulating inflammatory markers interleukin-6 (IL-6) and C-reactive protein (CRP) mediate the relationship between psychosocial work characteristics and diabetes. METHODS: We used three phases of data at 5 years intervals from the Whitehall II cohort study, originally recruiting 10,308 civil service employees aged 35-55 years. The data included repeat self-reports of job demands, control and social support, IL-6 from plasma samples, CRP from serum samples, and diabetes, ascertained through oral glucose tolerance test, medications, and self-reports of doctor-diagnosed diabetes. RESULTS: Structural equation models with age, sex and occupational position considering men and women combined, showed that low social support at work, but not high job demands or low job control, was prospectively associated with diabetes (standardized ß  =  0.05, 95% confidence interval (CI) 0.01-0.09) and higher levels of IL-6 (ß  =  0.03, CI 0.00-0.06). The inflammatory markers and diabetes were bidirectionally associated over time. A mediation model including workplace social support, IL-6 and diabetes further showed that 10% of the association between social support and diabetes over the three repeat examinations (total effect ß  =  0.08, CI 0.01-0.15) was attributable to a weak indirect effect through IL-6 (ß  =  0.01, CI 0.00-0.02). A similar indirect effect was observed for CRP in men only, while job control was prospectively associated with IL-6 among women. CONCLUSIONS: This study indicates an association between poor workplace support and diabetes that is partially ascribed to an inflammatory response.

Obesity and loss of disease-free years owing to major non-communicable diseases: a multicohort study.

BACKGROUND: Obesity increases the risk of several chronic diseases, but the extent to which the obesity-related loss of disease-free years varies by lifestyle category and across socioeconomic groups is unclear. We estimated the number of years free from major non-communicable diseases in adults who are overweight and obese, compared with those who are normal weight. METHODS: We pooled individual-level data on body-mass index (BMI) and non-communicable diseases from men and women with no initial evidence of these diseases in European cohort studies from the Individual-Participant-Data Meta-Analysis in Working Populations consortium. BMI was assessed at baseline (1991-2008) and non-communicable diseases (incident type 2 diabetes, coronary heart disease, stroke, cancer, asthma, and chronic obstructive pulmonary disease) were ascertained via linkage to records from national health registries, repeated medical examinations, or self-report. Disease-free years from age 40 years to 75 years associated with underweight (BMI <18·5 kg/m2), overweight (≥25 kg/m2 to <30 kg/m2), and obesity (class I [mild] ≥30 kg/m2 to <35 kg/m2; class II-III [severe] ≥35 kg/m2) compared with normal weight (≥18·5 kg/m2 to <25 kg/m2) were estimated. FINDINGS: Of 137 503 participants from ten studies, we excluded 6973 owing to missing data and 10 349 with prevalent disease at baseline, resulting in an analytic sample of 120 181 participants. Of 47 127 men, 211 (0·4%) were underweight, 21 468 (45·6%) normal weight, 20 738 (44·0%) overweight, 3982 (8·4%) class I obese, and 728 (1·5%) class II-III obese. The corresponding numbers among the 73 054 women were 1493 (2·0%), 44 760 (61·3%), 19 553 (26·8%), 5670 (7·8%), and 1578 (2·2%), respectively. During 1 328 873 person-years at risk (mean follow-up 11·5 years [range 6·3-18·6]), 8159 men and 8100 women developed at least one non-communicable disease. Between 40 years and 75 years, the estimated number of disease-free years was 29·3 (95% CI 28·8-29·8) in normal-weight men and 29·4 (28·7-30·0) in normal-weight women. Compared with normal weight, the loss of disease-free years in men was 1·8 (95% CI -1·3 to 4·9) for underweight, 1·1 (0·7 to 1·5) for overweight, 3·9 (2·9 to 4·9) for class I obese, and 8·5 (7·1 to 9·8) for class II-III obese. The corresponding estimates for women were 0·0 (-1·4 to 1·4) for underweight, 1·1 (0·6 to 1·5) for overweight, 2·7 (1·5 to 3·9) for class I obese, and 7·3 (6·1 to 8·6) for class II-III obese. The loss of disease-free years associated with class II-III obesity varied between 7·1 and 10·0 years in subgroups of participants of different socioeconomic level, physical activity level, and smoking habit. INTERPRETATION: Mild obesity was associated with the loss of one in ten, and severe obesity the loss of one in four potential disease-free years during middle and later adulthood. This increasing loss of disease-free years as obesity becomes more severe occurred in both sexes, among smokers and non-smokers, the physically active and inactive, and across the socioeconomic hierarchy. FUNDING: NordForsk, UK Medical Research Council, US National Institute on Aging, Academy of Finland, Helsinki Institute of Life Science, and Cancer Research UK.

Job strain and atrial fibrillation - Results from the Swedish Longitudinal Occupational Survey of Health and meta-analysis of three studies.

Background Knowledge about the impact of occupational exposures, such as work stress, on the risk of atrial fibrillation is limited. The present study aims to investigate the association between job strain, a measure of work stress, and atrial fibrillation. Design Prospective cohort study design and fixed-effect meta-analysis. Methods Data from the Swedish Longitudinal Occupational Survey of Health (SLOSH) was utilised for the main analysis, combining self-reported data on work stress at baseline with follow-up data on atrial fibrillation from nationwide registers. Cox proportional hazard regression analyses were used to estimate hazard ratios and 95% confidence intervals (CIs). A fixed-effect meta-analysis was conducted to pool the results from the present study with results from two similar previously published studies. Results Based on SLOSH data, job strain was associated with an almost 50% increased risk of atrial fibrillation (hazard ratio 1.48, 95% CI 1.00-2.18) after adjustment for age, sex and education. Further adjustment for smoking, physical activity, body mass index and hypertension did not alter the estimated risk. The meta-analysis of the present and two previously published studies showed a consistent pattern, with job strain being associated with increased risk of atrial fibrillation in all three studies. The estimated pooled hazard ratio was 1.37 (95% CI 1.13-1.67). Conclusion The results highlight that occupational exposures, such as work stress, may be important risk factors for incident atrial fibrillation.

Job strain and loss of healthy life years between ages 50 and 75 by sex and occupational position: analyses of 64 934 individuals from four prospective cohort studies.

OBJECTIVES: Poor psychosocial working conditions increase the likelihood of various types of morbidity and may substantially limit quality of life and possibilities to remain in paid work. To date, however, no studies to our knowledge have quantified the extent to which poor psychosocial working conditions reduce healthy or chronic disease-free life expectancy, which was the focus of this study. METHODS: Data were derived from four cohorts with repeat data: the Finnish Public Sector Study (Finland), GAZEL (France), the Swedish Longitudinal Occupational Survey of Health (Sweden) and Whitehall II (UK). Healthy (in good self-rated health) life expectancy (HLE) and chronic disease-free (free from cardiovascular disease, cancer, respiratory disease and diabetes) life expectancy (CDFLE) was calculated from age 50 to 75 based on 64 394 individuals with data on job strain (high demands in combination with low control) at baseline and health at baseline and follow-up. RESULTS: Multistate life table models showed that job strain was consistently related to shorter HLE (overall 1.7 years difference). The difference in HLE was more pronounced among men (2.0 years compared with 1.5 years for women) and participants in lower occupational positions (2.5 years among low-grade men compared with 1.7 years among high-grade men). Similar differences in HLE, although smaller, were observed among those in intermediate or high occupational positions. Job strain was additionally associated with shorter CDFLE, although this association was weaker and somewhat inconsistent. CONCLUSIONS: These findings suggest that individuals with job strain have a shorter health expectancy compared with those without job strain.

Longitudinal Mediation Modeling of Unhealthy Behaviors as Mediators between Workplace Demands/Support and Depressive Symptoms.

Lifestyle has been regarded as a key pathway through which adverse psychosocial working characteristics can give rise to long-term health problems. The purpose of this study was to estimate the indirect/mediated effect of health behaviors in the longitudinal work characteristics-depression relationship. The analyses were based on the Swedish Longitudinal Occupational Survey of Health, including 3706 working participants with repeat survey measures on four occasions (2008, 2010, 2012 and 2014). Psychosocial work characteristics including demands and social support were analyzed in relation to depressive symptoms. Autoregressive longitudinal mediation models using structural equation modeling were used to estimate the intermediate effects of unhealthy behaviors including current smoking, excessive alcohol consumption, unhealthy diet and physical inactivity. Both workplace demands and social support were related to later depressive symptoms. In bivariate models we found no significant paths from workplace demands to health behaviors, but two out of three significant time-specific paths from workplace support to excessive drinking and from excessive drinking to depressive symptoms. Social support was also associated with subsequent unhealthy diet, and one path from unhealthy diet to depressive symptoms was found. However, despite indications of certain longitudinal relationships between psychosocial working conditions and health behaviors as well as between health behaviors and depressive symptoms, no significant intermediate effects were found (p>0.05). We conclude that changes in unhealthy behaviors over a period of two years are unlikely to act as strong intermediaries in the longitudinal relationship between job demands and depressive symptoms and between social support and depressive symptoms.

Work stress and risk of cancer: meta-analysis of 5700 incident cancer events in 116,000 European men and women.

OBJECTIVE: To investigate whether work related stress, measured and defined as job strain, is associated with the overall risk of cancer and the risk of colorectal, lung, breast, or prostate cancers. DESIGN: Meta-analysis of pooled prospective individual participant data from 12 European cohort studies including 116,056 men and women aged 17-70 who were free from cancer at study baseline and were followed-up for a median of 12 years. Work stress was measured and defined as job strain, which was self reported at baseline. Incident cancers (all n=5765, colorectal cancer n=522, lung cancer n=374, breast cancer n=1010, prostate cancer n=865) were ascertained from cancer, hospital admission, and death registers. Data were analysed in each study with Cox regression and the study specific estimates pooled in meta-analyses. Models were adjusted for age, sex, socioeconomic position, body mass index (BMI), smoking, and alcohol intake RESULTS: A harmonised measure of work stress, high job strain, was not associated with overall risk of cancer (hazard ratio 0.97, 95% confidence interval 0.90 to 1.04) in the multivariable adjusted analyses. Similarly, no association was observed between job strain and the risk of colorectal (1.16, 0.90 to 1.48), lung (1.17, 0.88 to 1.54), breast (0.97, 0.82 to 1.14), or prostate (0.86, 0.68 to 1.09) cancers. There was no clear evidence for an association between the categories of job strain and the risk of cancer. CONCLUSIONS: These findings suggest that work related stress, measured and defined as job strain, at baseline is unlikely to be an important risk factor for colorectal, lung, breast, or prostate cancers.

Job strain and tobacco smoking: an individual-participant data meta-analysis of 166,130 adults in 15 European studies.

BACKGROUND: Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job strain, is associated with tobacco smoking in working adults. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed cross-sectional data from 15 European studies comprising 166,130 participants. Longitudinal data from six studies were used. Job strain and smoking were self-reported. Smoking was harmonised into three categories never, ex- and current. We modelled the cross-sectional associations using logistic regression and the results pooled in random effects meta-analyses. Mixed effects logistic regression was used to examine longitudinal associations. Of the 166,130 participants, 17% reported job strain, 42% were never smokers, 33% ex-smokers and 25% current smokers. In the analyses of the cross-sectional data, current smokers had higher odds of job strain than never-smokers (age, sex and socioeconomic position-adjusted odds ratio: 1.11, 95% confidence interval: 1.03, 1.18). Current smokers with job strain smoked, on average, three cigarettes per week more than current smokers without job strain. In the analyses of longitudinal data (1 to 9 years of follow-up), there was no clear evidence for longitudinal associations between job strain and taking up or quitting smoking. CONCLUSIONS: Our findings show that smokers are slightly more likely than non-smokers to report work-related stress. In addition, smokers who reported work stress smoked, on average, slightly more cigarettes than stress-free smokers.