Longitudinal plasmode algorithms to evaluate statistical methods in realistic scenarios: an illustration applied to occupational epidemiology.

INTRODUCTION: Plasmode simulations are a type of simulations that use real data to determine the synthetic data-generating equations. Such simulations thus allow evaluating statistical methods under realistic conditions. As far as we know, no plasmode algorithm has been proposed for simulating longitudinal data. In this paper, we propose a longitudinal plasmode framework to generate realistic data with both a time-varying exposure and time-varying covariates. This work was motivated by the objective of comparing different methods for estimating the causal effect of a cumulative exposure to psychosocial stressors at work over time. METHODS: We developed two longitudinal plasmode algorithms: a parametric and a nonparametric algorithms. Data from the PROspective Québec (PROQ) Study on Work and Health were used as an input to generate data with the proposed plasmode algorithms. We evaluated the performance of multiple estimators of the parameters of marginal structural models (MSMs): inverse probability of treatment weighting, g-computation and targeted maximum likelihood estimation. These estimators were also compared to standard regression approaches with either adjustment for baseline covariates only or with adjustment for both baseline and time-varying covariates. RESULTS: Standard regression methods were susceptible to yield biased estimates with confidence intervals having coverage probability lower than their nominal level. The bias was much lower and coverage of confidence intervals was much closer to the nominal level when considering MSMs. Among MSM estimators, g-computation overall produced the best results relative to bias, root mean squared error and coverage of confidence intervals. No method produced unbiased estimates with adequate coverage for all parameters in the more realistic nonparametric plasmode simulation. CONCLUSION: The proposed longitudinal plasmode algorithms can be important methodological tools for evaluating and comparing analytical methods in realistic simulation scenarios. To facilitate the use of these algorithms, we provide R functions on GitHub. We also recommend using MSMs when estimating the effect of cumulative exposure to psychosocial stressors at work.

Job Strain, Overweight, and Diabetes: A 13-Year Prospective Study Among 12,896 Men and Women in Ontario.

OBJECTIVE: The American Diabetes Association recently called for research on social and environmental determinants of diabetes to intensify primary prevention. Recent epidemiological evidence suggests that frequent and modifiable psychosocial stressors at work might contribute to the development of diabetes, but more prospective studies are needed. We evaluated the relationship between job strain and diabetes incidence in 12,896 workers followed up over a 13-year period in Ontario, Canada. We also examined the modifying effect of body mass index in this relationship. METHODS: Data from Ontario respondents (35-74 years of age) to the 2000-2001, 2002, and 2003 cycles of the Canadian Community Health Survey were prospectively linked to the Ontario Health Insurance Plan database for physician services and the Canadian Institute for Health Information Discharge Abstract Database for hospital admissions. The sample consisted of actively employed participants with no previous diagnosis for diabetes. Cox proportional hazard regression models were performed to evaluate the relationship between job strain, obesity, and the incidence of diabetes. RESULTS: Overall, job strain was not associated with the incidence of diabetes (hazard ratio [HR] = 1.05; 95% confidence interval [CI] = 0.83-1.34). Among women, job strain was associated with an elevated risk of diabetes, although this finding did not reach statistical significance (HR = 1.36; 95% CI = 0.94-1.96). Among men, no association was observed (HR = 0.89; 95% CI = 0.65-1.22). Also, job strain increased the risk of diabetes among women with obesity (HR = 1.88; 95% CI = 1.14-3.08), whereas these stressors reduced the risk among men with obesity (HR = 0.58; 95% CI = 0.36-0.95). CONCLUSIONS: The current study suggests that lowering job strain might be an effective strategy for preventing diabetes among women, especially the high-risk group comprising women with obesity.

Effectiveness of a workplace intervention reducing psychosocial stressors at work on blood pressure and hypertension.

OBJECTIVES: To assess the effectiveness of a workplace intervention reducing psychosocial stressors at work in lowering blood pressure and hypertension prevalence. METHODS: The study design was a quasi-experimental pre-post study with an intervention group and a control group. Post-intervention measurements were collected 6 and 36 months after the midpoint of the intervention. Participants were all white-collar workers employed in three public organisations. At baseline, the intervention and the control groups were composed of 1088 and 1068 workers, respectively. The intervention was designed to reduce psychosocial stressors at work by implementing organisational changes. Adjusted changes in ambulatory blood pressure and hypertension prevalence were examined. RESULTS: Blood pressure and hypertension significantly decreased in the intervention group while no change was observed in the control group. The differential decrease in systolic blood pressure between the intervention and the control group was 2.0 mm Hg (95% CI: -3.0 to -1.0). The prevalence of hypertension decreased in the intervention group, when compared with the control group (prevalence ratio: 0.85 (95% CI: 0.74 to 0.98)). CONCLUSIONS: Findings suggest that psychosocial stressors at work are relevant targets for the primary prevention of hypertension. At the population level, systolic blood pressure reductions such as those observed in the present study could prevent a significant number of premature deaths and disabling strokes.

Cumulative exposure to psychosocial stressors at work and global cognitive function: the PROspective Quebec Study on Work and Health.

OBJECTIVES: Psychosocial stressors at work have been proposed as modifiable risk factors for mild cognitive impairment (MCI). This study aimed to evaluate the effect of cumulative exposure to psychosocial stressors at work on cognitive function. METHODS: This study was conducted among 9188 white-collar workers recruited in 1991-1993 (T1), with follow-ups 8 (T2) and 24 years later (T3). After excluding death, losses to follow-up and retirees at T2, 5728 participants were included. Psychosocial stressors at work were measured according to the Karasek's questionnaire. Global cognitive function was measured with the Montreal Cognitive Assessment. Cumulative exposures to low psychological demand, low job control, passive job and high strain job were evaluated using marginal structural models including multiple imputation and inverse probability of censoring weighting. RESULTS: In men, cumulative exposures (T1 and T2) to low psychological demand, low job control or passive job were associated with higher prevalences of more severe presentation of MCI (MSMCI) at T3 (Prevalence ratios (PRs) and 95% CIs of 1.50 (1.16 to 1.94); 1.38 (1.07 to 1.79) and 1.55 (1.20 to 2.00), respectively), but not with milder presentation of MCI. In women, only exposure to low psychological demand or passive job at T2 was associated with higher prevalences of MSMCI at T3 (PRs and 95% CI of 1.39 (0.97 to 1.99) and 1.29 (0.94 to 1.76), respectively). CONCLUSIONS: These results support the deleterious effect of a low stimulating job on cognitive function and the cognitive reserve theory. Psychosocial stressors at work could be part of the effort for the primary prevention of cognitive decline.

Validation of case definitions of depression derived from administrative data against the CIDI-SF as reference standard: results from the PROspective Québec (PROQ) study.

BACKGROUND: Administrative data have several advantages over questionnaire and interview data to identify cases of depression: they are usually inexpensive, available for a long period of time and are less subject to recall bias and differential classification errors. However, the validity of administrative data in the correct identification of depression has not yet been studied in general populations. The present study aimed to 1) evaluate the sensitivity and specificity of administrative cases of depression using the validated Composite International Diagnostic Interview - Short Form (CIDI-SF) as reference standard and 2) compare the known-groups validity between administrative and CIDI-SF cases of depression. METHODS: The 5487 participants seen at the last wave (2015-2018) of the PROQ cohort had CIDI-SF questionnaire data linked to hospitalization and medical reimbursement data provided by the provincial universal healthcare provider and coded using the International Classification of Disease. We analyzed the sensitivity and specificity of several case definitions of depression from this administrative data. Their association with known predictors of depression was estimated using robust Poisson regression models. RESULTS: Administrative cases of depression showed high specificity (≥ 96%), low sensitivity (19-32%), and rather low agreement (Cohen's kappa of 0.21-0.25) compared with the CIDI-SF. These results were consistent over strata of sex, age and education level and with varying case definitions. In known-groups analysis, the administrative cases of depression were comparable to that of CIDI-SF cases (RR for sex: 1.80 vs 2.03 respectively, age: 1.53 vs 1.40, education: 1.52 vs 1.28, psychological distress: 2.21 vs 2.65). CONCLUSION: The results obtained in this large sample of a general population suggest that the dimensions of depression captured by administrative data and by the CIDI-SF are partially distinct. However, their known-groups validity in relation to risk factors for depression was similar to that of CIDI-SF cases. We suggest that neither of these data sources is superior to the other in the context of large epidemiological studies aiming to identify and quantify risk factors for depression.

Validity of participants' self-reported diagnosis for a work absence due to a mental health problem compared with physician-certified diagnosis for the same work absence among 709 Canadian workers.

OBJECTIVES: This study assesses the validity of a self-reported mental health problem (MHP) diagnosis as the reason for a work absence of 5 days or more compared with a physician-certified MHP diagnosis related to the same work absence. The potential modifying effect of absence duration on validity is also examined. METHODS: A total of 709 participants (1031 sickness absence episodes) were selected and interviewed. Total per cent agreement, Cohen's kappa, sensitivity and specificity values were calculated using the physician-certified MHP diagnosis related to a given work absence as the reference standard. Stratified analyses of total agreement, sensitivity and specificity values were also examined by duration of work absence (5-20 workdays,>20 workdays). RESULTS: Total agreement value for self-reported MHP was 90%. Cohen's kappa value was substantial (0.74). Sensitivity was 77% and specificity was 95%. Absences of more than 20 workdays had a better sensitivity than absences of shorter duration. A high specificity was observed for both short and longer absence episodes. CONCLUSION: This study showed high specificity and good sensitivity of self-reported MHP diagnosis compared with physician-certified MHP diagnosis for the same work absence. Absences of longer durations had a better sensitivity.

Differences between women and men in the relationship between psychosocial stressors at work and work absence due to mental health problem.

OBJECTIVES: Women have a higher incidence of mental health problems compared with men. Psychosocial stressors at work are associated with mental health problems. However, few prospective studies have examined the association between these stressors and objectively measured outcomes of mental health. Moreover, evidence regarding potential differences between women and men in this association is scarce and inconsistent. This study investigates whether psychosocial stressors at work are associated with the 7.5-year incidence of medically certified work absence due to a mental health problem, separately for women and men. METHODS: Data from a prospective cohort of white-collar workers in Canada (n=7138; 47.3% women) were used. We performed Cox regression models to examine the prospective association between self-reported psychosocial stressors at work (job strain model) at baseline and the 7.5-year HR of medically certified work absence of ≥5 days due to a mental health problem. RESULTS: During follow-up, 11.9% of participants had a certified work absence, with a twofold higher incidence among women. Women (HR 1.40, 95% CI 1.01 to 1.93) and men (HR 1.41, 95% CI 0.97 to 2.05) exposed to high strain (high demands and low control) had a higher incidence of work absence compared with those unexposed. Among women only, those exposed to an active job situation (high demands and high control) also had a higher risk (HR 1.82, 95% CI 1.29 to 2.56). CONCLUSIONS: Prevention efforts aimed at reducing psychosocial stressors at work could help lower the risk of work absence for both women and men. However, important differences between women and men need to be further studied in order to orient these efforts.

Psychosocial work stressors, high family responsibilities, and psychological distress among women: A 5-year prospective study.

BACKGROUND: Psychological distress is a strong and independent predictor of major depression. Assuming multiple roles (such as being both a mother and an employee) under stressful conditions may lead to psychological distress. This study evaluated, for the first time, the longitudinal effect of the simultaneous exposure to psychosocial work stressors and high family responsibilities on women's psychological distress. METHODS: Women were assessed at baseline (N = 1307) and at 3- and 5-year follow-ups. Psychosocial work stressors of the demand-control and effort-reward imbalance models were measured with validated questionnaires. Family responsibilities were also self-reported and referred to the number of children and their age(s) as well as housework and childcare. Psychological distress was measured with the validated Psychiatric Symptoms Index questionnaire. Prevalence ratios (PR) of psychological distress were modeled with log-binomial regressions. RESULTS: Having high family responsibilities did not increase women's prevalence of psychological distress. However, being exposed to either job strain or effort-reward imbalance led to a higher prevalence of psychological distress at the 3- and 5-year follow-ups (PR of 1.25-1.62). Being simultaneous exposed to these psychosocial work stressors and high family responsibilities also increased the prevalence of psychological distress (PR of 1.44-1.87), but no interactions were observed between stressors and responsibilities. CONCLUSIONS: In this 5-year prospective study, simultaneous exposure to psychosocial work stressors and high family responsibilities increased the prevalence of psychological distress among women. Work stressors were, however, driving most of the effect, which reinforces their importance as modifiable risk factors of women's mental health problems.

A test for the correct specification of marginal structural models.

Marginal structural models (MSMs) allow estimating the causal effect of a time-varying exposure on an outcome in the presence of time-dependent confounding. The parameters of MSMs can be estimated utilizing an inverse probability of treatment weight estimator under certain assumptions. One of these assumptions is that the proposed causal model relating the outcome to exposure history is correctly specified. However, in practice, the true model is unknown. We propose a test that employs the observed data to attempt validating the assumption that the model is correctly specified. The performance of the proposed test is investigated with a simulation study. We illustrate our approach by estimating the effect of repeated exposure to psychosocial stressors at work on ambulatory blood pressure in a large cohort of white-collar workers in Québec City, Canada. Code examples in SAS and R are provided to facilitate the implementation of the test.

Assessment of the healthy worker survivor effect in the relationship between psychosocial work-related factors and hypertension.

OBJECTIVES: The healthy worker survivor effect (HWSE) usually leads to underestimation of the effects of harmful occupational exposures. HWSE is characterised by the concomitance of three associations: (1) job status-subsequent exposure, (2) job status-disease and (3) previous exposure-job status. No study has reported the coexistence of these associations in the relationship between psychosocial work-related factors and health. We assessed if HWSE is present when measuring the effects of cumulative exposure to psychosocial work-related factors on the prevalence of hypertension in white-collar workers. METHODS: Data were obtained from two timepoints (1991-1993 at baseline and 1999-2001 at follow-up) of a prospective cohort study. At baseline, the population was composed of 9188 white-collar employees (women: 49.9%) in Quebec City. Job strain as psychosocial work-related factor and blood pressure were measured using validated methods. Job status (retirees vs employees) at follow-up was self-reported. Multiple multilevel robust Poisson regressions were used to estimate prevalence ratios of hypertension and risk ratios of retirement separately by gender. We performed multiple imputations to control selection bias due to missing values. RESULTS: Retirement eliminated the subsequent exposure to job strain de facto and was associated with the reduction in the prevalence of hypertension in younger (-33%) and older (-11%) men and in older women (-39%). Job strain was associated with job status in younger men and in women of any age. CONCLUSION: Data showed the presence of HWSE in younger men and older women given the coexistence of the three structural associations.

Psychosocial Stressors at Work and Ambulatory Blood Pressure.

PURPOSE OF REVIEW: Psychosocial stressors at work from the demand-latitude and effort-reward imbalance models are adverse exposures affecting about 20-25% of workers in industrialized countries. This review aims to summarize evidence on the effect of these stressors on blood pressure (BP). RECENT FINDINGS: Three systematic reviews have recently documented the effect of these psychosocial stressors at work on BP. Among exposed workers, statistically significant BP increases ranging from 1.5 to 11 mmHg have been observed in prospective studies using ambulatory BP (ABP). Recent studies using ABP have shown a deleterious effect of these psychosocial stressors at work on masked hypertension as well as on blood pressure control in pharmacologically treated patients. Evidence on the effect of these psychosocial stressors on BP supports the relevance to tackle these upstream factors for primary prevention and to reduce the burden of poor BP control. There is a need for increased public health and clinical awareness of the occupational etiology of high BP, hypertension, and poor BP control.

Effort-Reward Imbalance at Work and the Prevalence of Unsuccessfully Treated Hypertension Among White-Collar Workers.

We examined the association between effort-reward imbalance (ERI) exposure at work and unsuccessfully treated hypertension among white-collar workers from a large cohort in Quebec City, Canada. The study used a repeated cross-sectional design involving 3 waves of data collection (2000-2009). The study sample was composed of 474 workers treated for hypertension, accounting for 739 observations. At each observation, ERI was measured using validated scales, and ambulatory blood pressure (BP) was measured every 15 minutes during the working day. Unsuccessfully treated hypertension was defined as daytime ambulatory BP of at least 135/85 mm Hg and was further divided into masked and sustained hypertension. Adjusted prevalence ratios and 95% confidence intervals were estimated. Participants in the highest tertile of ERI exposure had a higher prevalence of unsuccessfully treated hypertension (prevalence ratio = 1.45, 95% confidence interval: 1.16, 1.81) after adjustment for gender, age, education, family history of cardiovascular diseases, body mass index, diabetes, smoking, sedentary behaviors, and alcohol intake. The present study supports the effect of adverse psychosocial work factors from the ERI model on BP control in treated workers. Reducing these frequent exposures at work might lead to substantial benefits on BP control at the population level.

Double Exposure to Adverse Psychosocial Work Factors and High Family Responsibilities as Related to Ambulatory Blood Pressure at Work: A 5-Year Prospective Study in Women With White-Collar Jobs.

OBJECTIVE: Accumulating evidence shows that psychosocial work factors of the demand-control and effort-reward imbalance models may contribute to increase blood pressure (BP). Women are more likely to be exposed to these psychosocial factors than men. Moreover, women spend twice as much time per week performing family responsibilities than men. This study aimed to evaluate the longitudinal association of the double exposure to psychosocial work factors and high family responsibilities in women with BP for a 5-year follow-up. METHODS: At baseline, the study sample was composed of 1215 working women. Psychosocial work factors were measured using validated scales. Family responsibilities were measured using items related to "the number of children and their age" and "housework and children care." Ambulatory BP measures were taken every 15 minutes during a working day. Associations between psychosocial measures and BP were examined using analyses of covariance. RESULTS: Women with a double exposure to effort-reward imbalance and high family responsibilities had significantly higher BP means than women not exposed to these factors at baseline (diastolic: +2.75 mm Hg), at 3-year follow-up (systolic: +2.22 mm Hg and diastolic: +2.55 mm Hg), and at 5-year follow-up (systolic: +2.94 mm Hg and diastolic: + 3.10 mm Hg). No adverse effect on BP was observed for the double exposure to the psychosocial work factors of the demand-control model and high family responsibilities. CONCLUSIONS: A double exposure to effort-reward imbalance at work and high family responsibilities might contribute to elevated ambulatory BP at work among women. BP elevations related to this double exposure may persist for several years.

Psychosocial work factors and social inequalities in psychological distress: a population-based study.

BACKGROUND: Mental health problems (MHP) are the leading cause of disability worldwide. The inverse association between socioeconomic position (SEP) and MHP has been well documented. There is prospective evidence that factors from the work environment, including adverse psychosocial work factors, could contribute to the development of MHP including psychological distress. However, the contribution of psychosocial work factors to social inequalities in MHP remains unclear. This study evaluates the contribution of psychosocial work factors from two highly supported models, the Demand-Control-Support (DCS) and the Effort-Reward Imbalance (ERI) models to SEP inequalities of psychological distress in men and women from a population-based sample of Quebec workers. METHODS: Data were collected during a survey on working conditions, health and safety at work. SEP was evaluated using education, occupation and household income. Psychosocial work factors and psychological distress were assessed using validated instruments. Mean differences (MD) in the score of psychological distress were estimated separately for men and women. RESULTS: Low education level and low household income were associated with psychological distress among men (MD, 0.56 (95% CI 0.06; 1.05) and 1.26 (95% CI 0.79; 1.73) respectively). In men, the contribution of psychosocial work factors from the DCS and the ERI models to the association between household income and psychological distress ranged from 9% to 24%. No clear inequalities were observed among women. CONCLUSIONS: These results suggest that psychosocial work factors from the DCS and the ERI models contribute to explain a part of social inequalities in psychological distress among men. Psychosocial factors at work are frequent and modifiable. The present study supports the relevance of targeting these factors for the primary prevention of MHP and for health policies aiming to reduce social inequalities in mental health.

Effort-reward imbalance at work and 5-year changes in blood pressure: the mediating effect of changes in body mass index among 1400 white-collar workers.

PURPOSE: A number of prospective studies have documented the effect of adverse psychosocial work factors (work stress) on high blood pressure (BP). Weight gain could be an important pathway by which work stress exerts its effect on BP. No previous prospective study has examined this mediating effect. The aim of the present study was to examine the mediating effect of body mass index (BMI) in the association between psychosocial work factors from Siegrist's effort-reward imbalance model (ERI) and ambulatory BP (ABP). METHODS: A prospective study was conducted among 1436 white-collar workers. Data were collected three times during a 5-year period. ERI was measured using validated scales, at each time. BMI was measured by a trained assistant. ABP was measured every 15 min during a working day. RESULTS: ERI exposure onset over 3 years was indirectly associated with ABP changes (0.49 mmHg; 95 % CI 0.05, 1.22), through BMI changes, in women with baseline BMI ≥25 kg/m2. An effect of similar magnitude and of borderline significance was observed for ERI chronic exposure. No mediating effect was observed among men, and using ERI exposure over 5 years. CONCLUSION: The mediating effect of BMI was of small magnitude and observed in certain subgroups and time frame only. Subgroup-specific mediating pathways might be involved to explain the effect of work stress on cardiovascular diseases risk.

Costs of presenteeism and absenteeism associated with psychological distress among male and female older workers: a cross-sectional study.

OBJECTIVE: We estimated, for women and men: 1) the associations between psychological distress and the prevalences of presenteeism and absenteeism, 2) average hours lost annually per person and 3) costs from the employers' economic perspective. METHODS: Participants were 1292 Canadian white-collar workers. Psychological distress, presenteeism and absenteeism were assessed with validated questionnaires. The average annual hours of productivity loss and related costs were estimated using generalized linear models with a negative binomial distribution and a log link. RESULTS: High psychological distress in women and men was associated with presenteeism costs ($6944 and $8432) and absenteeism costs ($2337 and $2796 per person). The association between psychological distress and annual hours lost to presenteeism was twice stronger for men than women. CONCLUSION: Productivity losses associated with psychological distress are high in women and men older workers.

Complete genome sequence of multidrug-resistant Enterobacter roggenkampii 0-E.

Here, we present the complete 4.77 Mb genome of Enterobacter roggenkampii 0-E assembled with Oxford Nanopore long reads. This genome harbors 19 antimicrobial resistance genes, including ramA and marA decreasing permeability to carbapenems. This genome adds novel knowledge on emerging multidrug resistance in the Enterobacter cloacae species complex.

Psychosocial work environment and ambulatory blood pressure: independent and combined effect of demand-control and effort-reward imbalance models.

BACKGROUND: Two main theoretical models have been used to assess the impact of psychosocial work factors on blood pressure (BP): the demand-control model (DC) and the effort-reward imbalance (ERI) model. Little is known about their independent and combined effect. OBJECTIVE: To examine the independent and combined effect of the DC and ERI models on ambulatory BP (ABP). METHOD: Data were collected three times over 7 years from 3395 white-collar women and men using a repeated cross-sectional design. On each occasion, psychosocial work factors were measured using validated scales. ABP was measured every 15 min during a working day. Systolic and diastolic ABP means were examined in relation to contemporaneous and past exposure. Both models were mutually adjusted. A combined exposure variable was computed. RESULTS: In men, high strain, and active, passive and ERI exposure were associated with ABP using contemporaneous exposure. However, the high strain/ABP association was not significant after adjustment for ERI. In women, no association was found with the DC model, while women exposed to ERI had higher ABP. Use of past exposure showed a stronger association between ABP and active exposure in men, while ERI associations were attenuated. Combined exposure to active jobs and to ERI was associated with ABP in both genders. CONCLUSIONS: In men, associations with the DC model were mixed. Associations between high job strain and ABP were not independent of ERI exposure while both DC intermediate groups were independently associated with ABP. In women, no association was found with the DC model. ERI exposure was independently associated with ABP using contemporaneous exposure, but not using past exposure. Combined active and ERI exposure was also associated with ABP.

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.

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.