Socioeconomic inequalities, psychosocial stressors at work and physician-diagnosed depression: Time-to-event mediation analysis in the presence of time-varying confounders.

OBJECTIVES: There is evidence that both low socioeconomic status (SES) and psychosocial stressors at work (PSW) increase risk of depression, but prospective studies on the contribution of PSW to the socioeconomic gradient of depression are still limited. METHODS: Using a prospective cohort of Quebec white-collar workers (n = 9188 participants, 50% women), we estimated randomized interventional analogues of the natural direct effect of SES indicators at baseline (education level, household income, occupation type and a combined measure) and of their natural indirect effects mediated through PSW (job strain and effort-reward imbalance (ERI) measured at the follow-up in 1999-2001) on incident physician-diagnosed depression. RESULTS: During 3 years of follow-up, we identified 469 new cases (women: 33.1 per 1000 person-years; men: 16.8). Mainly in men, low SES was a risk factor for depression [education: hazard ratio 1.72 (1.08-2.73); family income: 1.67 (1.04-2.67); occupational type: 2.13 (1.08-4.19)]. In the entire population, exposure to psychosocial stressors at work was associated with increased risk of depression [job strain: 1.42 (1.14-1.78); effort-reward imbalance (ERI) 1.73 (1.41-2.12)]. The estimated indirect effects of socioeconomic indicators on depression mediated through job strain ranged from 1.01 (0.99-1.03) to 1.04 (0.98-1.10), 4-15% of total effects, and for low reward from 1.02 (1.00-1.03) to 1.06 (1.01-1.11), 10-15% of total effects. DISCUSSION: Our study suggests that PSW only slightly mediate the socioeconomic gradient of depression, but that socioeconomic inequalities, especially among men, and PSW both increase the incidence of depression.

Psychosocial Stressors at Work and Coronary Heart Disease Risk in Men and Women: 18-Year Prospective Cohort Study of Combined Exposures.

BACKGROUND: Psychosocial stressors at work, like job strain and effort-reward imbalance (ERI), can increase coronary heart disease (CHD) risk. ERI indicates an imbalance between the effort and received rewards. Evidence about the adverse effect of combined exposure to these work stressors on CHD risk is scarce. This study examines the separate and combined effect of job strain and ERI exposure on CHD incidence in a prospective cohort of white-collar workers in Quebec, Canada. METHODS: Six thousand four hundred sixty-five white-collar workers without cardiovascular disease (mean age, 45.3±6.7) were followed for 18 years (from 2000 to 2018). Job strain and ERI were measured with validated questionnaires. CHD events were retrieved from medico-administrative databases using validated algorithms. Marginal Cox models were used to calculate hazard ratios (HR) stratified by sex. Multiple imputation and inverse probability weights were applied to minimize potential threats to internal validity. RESULTS: Among 3118 men, 571 had a first CHD event. Exposure to either job strain or ERI was associated with an adjusted 49% CHD risk increase (HR, 1.49 [95% CI, 1.07-2.09]). Combined exposure to job strain and ERI was associated with an adjusted 103% CHD risk increase (HR, 2.03 [95% CI, 1.38-2.97]). Exclusion of early CHD cases and censoring at retirement did not alter these associations. Among 3347 women, 265 had a first CHD event. Findings were inconclusive (passive job HR, 1.24 [95% CI, 0.80-1.91]; active job HR, 1.16 [95% CI, 0.70-1.94]; job strain HR, 1.08 [95% CI, 0.66-1.77]; ERI HR, 1.02 [95% CI, 0.72-1.45]). CONCLUSIONS: In this prospective cohort study, men exposed to job strain or ERI, separately and in combination, were at increased risk of CHD. Early interventions on these psychosocial stressors at work in men may be effective prevention strategies to reduce CHD burden. Among women, further investigation is required.

Job strain and effort-reward imbalance as risk factors for type 2 diabetes mellitus: A systematic review and meta-analysis of prospective studies.

OBJECTIVES: This systematic review and meta-analysis aimed to synthesize the available data on prospective associations between work-related stressors and the risk of type 2 diabetes mellitus (T2DM) among adult workers, according to the demand-control-support (DCS) and the effort-reward imbalance (ERI) models. METHOD: We searched for prospective studies in PubMed, EMBASE, Web of Science, Scopus, CINHAL and PsychInfo. After screening and extraction, quality of evidence was assessed using the ROBINS-I tool adapted for observational studies. The effect estimates extracted for each cohort were synthesized using random effect models. RESULTS: We included 18 studies (reporting data on 25 cohorts) in meta-analyses for job strain, job demands, job control, social support at work and ERI. Workers exposed to job strain had a higher risk of developing T2DM when compared to unexposed workers [pooled rate ratio (RR) 1.16, 95% confidence interval (CI) 1.07-1.26]. This association was robust in several supplementary analyses. For exposed women relative to unexposed women, the RR was 1.35 (95% CI 1.12-1.64). The RR of workers exposed to ERI was 1.24 (95% CI 1.08-1.42) compared to unexposed workers. CONCLUSIONS: This is the first meta-analysis to find an effect of ERI on the onset of T2DM incidence. It also confirms that job strain increases the incidence of T2DM, especially among women.

The change in estimate method for selecting confounders: A simulation study.

BACKGROUND: The change in estimate is a popular approach for selecting confounders in epidemiology. It is recommended in epidemiologic textbooks and articles over significance test of coefficients, but concerns have been raised concerning its validity. Few simulation studies have been conducted to investigate its performance. METHODS: An extensive simulation study was realized to compare different implementations of the change in estimate method. The implementations were also compared when estimating the association of body mass index with diastolic blood pressure in the PROspective Québec Study on Work and Health. RESULTS: All methods were susceptible to introduce important bias and to produce confidence intervals that included the true effect much less often than expected in at least some scenarios. Overall mixed results were obtained regarding the accuracy of estimators, as measured by the mean squared error. No implementation adequately differentiated confounders from non-confounders. In the real data analysis, none of the implementation decreased the estimated standard error. CONCLUSION: Based on these results, it is questionable whether change in estimate methods are beneficial in general, considering their low ability to improve the precision of estimates without introducing bias and inability to yield valid confidence intervals or to identify true confounders.

Job strain and incident cardiovascular disease: the confounding and mediating effects of lifestyle habits. An overview of systematic reviews.

This overview of systematic reviews (SR) aims to determine how the potential confounding and/or mediating effects of lifestyle habits were taken into consideration in SR examining the job strain effect on cardiovascular disease (CVD) incidence. Thirteen SR were identified. Lifestyle habits were often considered as confounders (n = 8). Authors reported that the job strain and CVD association remained after adjusting for lifestyle habits (n = 6); discussed lifestyle habits as potential mediators (n = 8) and postulated a total effect underestimation due to over-adjustment (n = 4). None investigated the magnitude of this bias.The effect of job strain on CVD is independent of lifestyle habits, supporting its causal effect on CVD. Lifestyle habits are also potential mediators. The current practice of adjusting for lifestyle habits can therefore lead to an underestimation of the total effect. Research using meditation methods is needed.

Psychosocial Stressors at Work and the Risk of Sickness Absence Due to a Diagnosed Mental Disorder: A Systematic Review and Meta-analysis.

Importance: Mental health problems are associated with considerable occupational, medical, social, and economic burdens. Psychosocial stressors at work have been associated with a higher risk of mental disorders, but the risk of sickness absence due to a diagnosed mental disorder, indicating a more severe condition, has never been investigated in a systematic review and meta-analysis. Objective: To synthesize the evidence of the association of psychosocial stressors at work with sickness absence due to a diagnosed mental disorder among adult workers. Data Sources: Seven electronic databases (MEDLINE, Embase, PsycInfo, Web of Science, CINAHL, Sociological Abstracts, and International Bibliography of the Social Sciences), 3 gray literature databases (Grey Literature Report, WHO-IRIS and Open Grey), and the reference lists of all eligible studies and reviews were searched in January 2017 and updated in February 2019. Study Selection: Only original prospective studies evaluating the association of at least 1 psychosocial stressor at work from the 3 most recognized theoretical models were eligible: the job demand-control-support model, including exposure to job strain (high psychological demands with low job control); effort-reward imbalance model; and organizational justice model. Study selection was performed in duplicate by blinded independent reviewers. Among the 28 467 citations screened, 23 studies were eligible for systematic review. Data Extraction and Synthesis: This meta-analysis followed the PRISMA and MOOSE guidelines. Data extraction and risk of bias evaluation, using the Risk of Bias in Nonrandomized Studies-Interventions tool, were performed in duplicate by blinded independent reviewers. Data were pooled using random-effect models. Main Outcomes and Measures: Sickness absence due to a mental disorder with a diagnosis obtained objectively. Results: A total of 13 studies representing 130 056 participants were included in the 6 meta-analyses. Workers exposed to low reward were associated with a higher risk of sickness absence due to a diagnosed mental disorder compared with nonexposed workers (pooled risk ratio [RR], 1.76 [95% CI, 1.49-2.08]), as were those exposed to effort-reward imbalance (pooled RR, 1.66 [95% CI, 1.37-2.00]), job strain (pooled RR, 1.47 [95% CI, 1.24-1.74]), low job control (pooled RR, 1.25 [95% CI, 1.02-1.53]), and high psychological demands (pooled RR, 1.23 [95% CI, 1.04-1.45]). Conclusions and Relevance: This meta-analysis found that workers exposed to psychosocial stressors at work were associated with a higher risk of sickness absence due to a mental disorder. A better understanding of the importance of these stressors could help physicians when evaluating their patients' mental health and work capacity.

Participant Evaluation of a Prediabetes Intervention Program Designed for Rural Adults.

The type 2 diabetes epidemic is a global crisis threatening the health and economies of many nations. This study aimed to evaluate a prediabetes intervention program designed for rural adults in southwestern Ontario based on the feedback of participants. Rural adults with prediabetes were referred by physicians to an intervention program developed to assist with unique barriers rural adults face related to the built environment and socioeconomic status when adopting a healthy lifestyle. After 6 monthly education sessions offered by a dietitian and a nurse, participants completed a questionnaire to share their program experience. In addition, 6 focus groups consisting of 5-9 participants were conducted to assess program acceptability, feasibility, and practicality. Of 49 enrolled, 35 participants aged 60.8 ± 7.1 (mean ± SD) evaluated the program. Participants reported finding the program to be acceptable, feasible, and practical due to the interactive nature of the sessions, the group setting and the availability of health professionals. This prediabetes lifestyle intervention program was perceived as successfully addressing rural adults' needs in terms of adopting a healthy lifestyle. Feedback received through program evaluation, which included a participant experience survey and focus groups has helped improve this program and may benefit other prediabetes education intervention programs.

Job strain and the prevalence of uncontrolled hypertension among white-collar workers.

To determine whether white-collar workers treated for hypertension who are exposed to psychosocial stressors at work have a higher prevalence of uncontrolled hypertension than unexposed workers, this study conducted three waves of data collection over a 5-year period (repeated cross-sectional design). The study sample was composed of 464 white-collar workers treated for hypertension. At each collection time, ambulatory blood pressure (ABP) was measured every 15 min during the workday. Uncontrolled hypertension was defined as a mean daytime systolic ABP ≥135 mmHg and/or diastolic ABP ≥85 mmHg for non-diabetic participants and systolic ABP ≥125 mmHg and/or diastolic ABP ≥75 mmHg for diabetic participants. Job strain was evaluated with Karasek's demand-latitude model using validated scales for psychological demands and decision latitude. Prevalence ratios (PR) and 95% confidence intervals (CI) were estimated using generalized estimating equations, adjusting for sociodemographic and lifestyle-related risk factors. Men with job strain (high demands and low latitude) and active jobs (high demands and high latitude) had a higher prevalence of uncontrolled hypertension (PR job strain = 1.46, 95% CI: 1.07-1.98 and PR active = 1.47, 95% CI: 1.12-1.94). When considered separately, high demands were associated with a higher prevalence of uncontrolled hypertension in both men (PR highest tertile = 1.60, 95% CI: 1.25-2.06) and women (PR highest tertile = 1.60, 95% CI: 1.03-2.47). Workers exposed to psychosocial stressors at work according to the demand-latitude model had a higher prevalence of uncontrolled hypertension. Reducing these frequent exposures could help to reduce the burden of uncontrolled hypertension.

Diet quality indices in relation to metabolic syndrome in an Indigenous Cree (Eeyouch) population in northern Québec, Canada.

OBJECTIVE: To assess associations between three diet quality indices and metabolic syndrome (MetS) in the Cree (Eeyouch) of northern Québec, Canada, as well as to evaluate their pertinence in this Indigenous context. DESIGN: The alternative-Healthy Eating Index 2010 (aHEI-2010), the Food Quality Score (FQS) and the contribution of ultra-processed products (UPP) to total daily dietary energy intake using the NOVA classification were calculated from 24 h food recalls. MetS was determined with the latest harmonized definition. Logistic regressions assessed the relationship between quintiles of dietary quality scores with MetS and its components. SETTING: Study sample from the 2005-2009 cross-sectional Nituuchischaayihititaau Aschii Environment-and-Health Study. SUBJECTS: Eeyouch (n 811) from seven James Bay communities (≥18 years old). RESULTS: MetS prevalence was 56·6 % with 95·4 % abdominal adiposity, 50·1 % elevated fasting plasma glucose, 43·4 % hypertension, 38·6 % elevated TAG and 44·5 % reduced HDL cholesterol. Comparing highest and lowest quintiles of scores, adjusted OR (95 % CI) of MetS was 0·70 (0·39, 1·08; P-trend=0·05) for aHEI-2010, 1·06 (0·63, 1·76; P-trend=0·87) for FQS and 1·90 (1·14, 3·17; P-trend=0·04) for the contribution of UPP to total daily dietary energy intake. CONCLUSIONS: Although diet quality indices have been associated with cardiometabolic risk, only the dietary intake of UPP was significantly associated with MetS in the Eeyouch. Indices tailored to the food environment of northern communities are essential to further understand the impact of diet quality in this context.