Job strain and clinical depression - authors' reply

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Associations between combinations of job demands and job control among 6,16,818 people aged 55-64 in paid work with their labour market status 11 years later: a prospective cohort study.

BACKGROUND: Given current discussions about extending working lives, more knowledge is needed on working conditions associated with labour market status in older age. OBJECTIVE: To explore associations between combinations of job demands and job control among workers aged 55-64 years and their labour market status 11 years later. METHODS: A population-based prospective cohort study using nationwide register data. The 616,818 individuals in Sweden aged 55-64 who in 2001 were in paid work were categorised using a job exposure matrix based on tertiles (reference = medium control/medium demands). Participants were followed up in 2012 regarding their main labour market status (paid work, old-age pension, no income/social assistance, sickness absence/disability pension, emigrated, dead; reference = old-age pension) using multinomial logistic regression for odds ratios (OR) and 95% confidence intervals (CI). The fully adjusted analyses included adjustment for sociodemographic factors and unemployment or sickness absence/disability pension for more than half the year in 2001. RESULTS: Those in occupations with low job control at baseline were less likely to be in paid work at follow-up (OR low demands/low control 0.74, CI 0.71-0.78; high demands/low control 0.81, CI 0.75-0.87). Those in occupations with baseline high demands were less likely to have no income/social assistance at follow-up (OR high demands/low control 0.71, CI 0.52-0.96; high demands/high control 0.59, CI 0.47-0.75). CONCLUSION: Job demands and control when aged 55-64 were associated with labour market status 11 years later: high control was associated with greater chance of being in paid work, and high demands were associated with lower risk of no income/social assistance

Searching for observational studies: what does citation tracking add to PubMed? A case study in depression and coronary heart disease

BACKGROUND: PubMed is the most widely used method for searches of the medical literature, but fails to identify many relevant articles. Electronic citation tracking offers an alternative search method. METHODS: Articles investigating the role of depression in the aetiology and prognosis of coronary heart disease were sought through two methods: a) PubMed, and b) citation tracking where Science Citation Index was searched for all articles which cited ("forward citation tracking") or were cited by ("backward citation tracking") any of the articles in an index review. The number and quality of eligible articles identified by the two methods were compared. RESULTS: 50 articles that were not already included in the index review met our inclusion criteria; 11 were identified through Science Citation Index alone, 8 through PubMed alone, and 31 through both methods. Articles identified by Science Citation Index alone were published in higher impact factor journals, were larger and were less likely to show a positive association. CONCLUSION: Science Citation Index identified more eligible articles than PubMed, and these differed qualitatively. Failing to use citation tracking in a systematic review of observational studies may result in bias

Inter-rater reliability of direct observations of the physical and psychosocial working conditions in eldercare: An evaluation in the DOSES project

The aim of the study was to develop and evaluate the reliability of the “Danish observational study of eldercare work and musculoskeletal disorders” (DOSES) observation instrument to assess physical and psychosocial risk factors for musculoskeletal disorders (MSD) in eldercare work. During 1.5 years, sixteen raters conducted 117 inter-rater observations from 11 nursing homes. Reliability was evaluated using percent agreement and Gwet's AC1 coefficient. Of the 18 examined items, inter-rater reliability was excellent for 7 items (AC1>0.75) fair to good for 7 items (AC1 0.40–0.75) and poor for 2 items (AC1 0–0.40). For 2 items there was no agreement between the raters (AC1 <0). The reliability did not differ between the first and second half of the data collection period and the inter-rater observations were representative regarding occurrence of events in eldercare work. The instrument is appropriate for assessing physical and psychosocial risk factors for MSD among eldercare workers

Workplace psychosocial resources and risk of cardiovascular disease among employees: a multi-cohort study of 135 669 participants

Objective In terms of prevention, it is important to determine effects on cardiovascular disease (CVD) when some workplace psychosocial resources are high while others are low. The aim of the study was to assess the prospective relationship between clustering of workplace psychosocial resources and risk of CVD among employees. Methods We pooled data from three cohort studies of 135 669 employees (65% women, age 18–65 years and free of CVD) from Denmark, Finland and Sweden. Baseline horizontal resources (culture of collaboration and support from colleagues) and vertical resources (leadership quality and procedural justice) were measured using standard questionnaire items. Incident CVD, including coronary heart and cerebrovascular disease, was ascertained using linked electronic health records. We used latent class analysis to assess clustering (latent classes) of workplace psychosocial resources. Cox proportional hazard models were used to examine the association between these clusters and risk of CVD, adjusting for demographic and employment-related factors and pre-existing physical and mental disorders. Results We identified five clusters of workplace psychosocial resources from low on both vertical and horizontal resources (13%) to generally high resources (28%). High horizontal resources were combined with either inter-mediate [hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.74–0.95] or high (HR 0.88, 95% CI 0.78–1.00) vertical resources were associated with lower risks of CVD compared to those with generally low resources. The association was most prominent for cerebrovascular disease (eg, general high resources: HR 0.80, 95% CI 0.67–0.96). Conclusions Individuals with high levels of workplace psychosocial resources across horizontal and vertical dimensions have a lower risk of CVD, particularly cerebrovascular disease

Patterns in the Occurrence and Duration of Musculoskeletal Pain and Interference with Work among Eldercare Workers-A One-Year Longitudinal Study with Measurements Every Four Weeks

The objective of this study was to examine patterns of musculoskeletal pain episodes over time. We conducted a one-year follow-up study among 275 eldercare workers with measurements of musculoskeletal pain (low back pain (LBP) and neck/shoulder pain (NSP)) and pain-related work interferenc

Contribution of income and job strain to the association between education and cardiovascular disease in 1.6 million Danish employees

AIMS: We examined the extent to which associations between education and cardiovascular disease (CVD) morbidity and mortality are attributable to income and work stress. METHODS AND RESULTS: We included all employed Danish residents aged 30-59 years in 2000. Cardiovascular disease morbidity analyses included 1 638 270 individuals, free of cardiometabolic disease (CVD or diabetes). Mortality analyses included 41 944 individuals with cardiometabolic disease. We assessed education and income annually from population registers and work stress, defined as job strain, with a job-exposure matrix. Outcomes were ascertained until 2014 from health registers and risk was estimated using Cox regression. During 10 957 399 (men) and 10 776 516 person-years (women), we identified 51 585 and 24 075 incident CVD cases, respectively. For men with low education, risk of CVD was 1.62 [95% confidence interval (CI) 1.58-1.66] before and 1.46 (95% CI 1.42-1.50) after adjustment for income and job strain (25% reduction). In women, estimates were 1.66 (95% CI 1.61-1.72) and 1.53 (95% CI 1.47-1.58) (21% reduction). Of individuals with cardiometabolic disease, 1736 men (362 234 person-years) and 341 women (179 402 person-years) died from CVD. Education predicted CVD mortality in both sexes. Estimates were reduced with 54% (men) and 33% (women) after adjustment for income and job strain. CONCLUSION: Low education predicted incident CVD in initially healthy individuals and CVD mortality in individuals with prevalent cardiometabolic disease. In men with cardiometabolic disease, income and job strain explained half of the higher CVD mortality in the low education group. In healthy men and in women regardless of cardiometabolic disease, these factors explained 21-33% of the higher CVD morbidity and mortality

Effort-reward imbalance at work and risk of type 2 diabetes in a national sample of 50,552 workers in Denmark : A prospective study linking survey and register data

Objective: To examine the prospective relation between effort-reward imbalance at work and risk of type 2 diabetes. Methods: We included 50,552 individuals from a national survey of the working population in Denmark, aged 30-64 years and diabetes-free at baseline. Effort-reward imbalance was defined, in accordance with the literature, as a mismatch between high efforts at work (e.g. high work pace, time pressure), and low rewards received in return (e.g. low recognition, job insecurity) and assessed as a continuous and a categorical variable. Incident type 2 diabetes was identified in national health registers. Using Cox regression we calculated hazard ratios (HR) and 95% confidence intervals (95% CI) for estimating the association between effort-reward imbalance at baseline and risk of onset of type 2 diabetes during follow-up, adjusted for sex, age, socioeconomic status, cohabitation, children at home, migration background, survey year and sample method. Results: During 136,239 person-years of follow-up (mean = 2.7 years) we identified 347 type 2 diabetes cases (25.5 cases per 10,000 person-years). For each one standard deviation increase of the effort-reward imbalance score at baseline, the fully adjusted risk of type 2 diabetes during follow-up increased by 9% (HR: 1.09, 95% CI: 0.98-1.21). When we used effort-reward imbalance as a dichotomous variable, exposure to effort-reward imbalance was associated with an increased risk of type 2 diabetes with a HR of 1.27 (95% CI: 1.02-1.58). Conclusion The results of this nationwide study of the Danish workforce suggest that effort-reward imbalance at work may be a risk factor for type 2 diabetes.Peer reviewe

Onset of Workplace Bullying and Risk of Weight Gain: A Multicohort Longitudinal Study

OBJECTIVE: This study aimed to examine the onset of workplace bullying as a risk factor for BMI increase. METHODS: Repeated biennial survey data from three Nordic cohort studies were used, totaling 46,148 participants (67,337 participant observations) aged between 18 and 65 who did not have obesity and who were not bullied at the baseline. Multinomial logistic regression was applied for the analysis under the framework of generalized estimating equations. RESULTS: Five percent reported onset of workplace bullying within 2 years from the baseline. In confounder-adjusted models, onset of workplace bullying was associated with a higher risk of weight gain of ≥ 1 BMI unit (odds ratio = 1.09; 95% CI: 1.01-1.19) and of ≥ 2.5 BMI units (odds ratio = 1.24; 95% CI: 1.06-1.45). A dose-response pattern was observed, and those exposed to workplace bullying more frequently showed a higher risk (Ptrend  = 0.04). The association was robust to adjustments, restrictions, stratifications, and use of relative/absolute scales for BMI change. CONCLUSIONS: Participants with exposure to the onset of workplace bullying were more likely to gain weight, a possible pathway linking workplace bullying to increased long-term risk of type 2 diabetes