Shift and Night Work and All-Cause and Cause-Specific Mortality: Prospective Results From the STRESSJEM Study.

The literature remains sparse and inconclusive about the impact of shift and night work on mortality, and still more on specific causes of death. The objectives were to explore the prospective associations between exposure to shift and night work and all-cause and cause-specific mortality. The study was based on a large national representative French prospective cohort of 1,511,456 employees followed up from 1976 to 2002. Exposure to shift and night work relied on a job-exposure matrix, and 3 time-varying measures (current, cumulative, and recency-weighted cumulative exposure) were constructed. Mortality and causes of death were provided by the national registry, and all-cause, cardiovascular, cancer and preventable mortality, and suicide were studied. Cox proportional hazards models were performed to study the associations between shift and night work and mortality. During follow-up, 22,105 deaths occurred for all-cause mortality. In the study of mortality until the end of last job during follow-up, shift and/or night work were associated with all-cause, cardiovascular, cancer and preventable mortality, and suicide (except night without shift work with cancer mortality and suicide) among men. Shift work (especially shift without night work) was associated with all-cause, cancer and preventable mortality among women. The results were similar for current, cumulative, and recency-weighted cumulative exposure. Associations were found for more detailed causes of death: cerebrovascular diseases for both genders, ischemic heart diseases, respiratory cancers, smoking-related mortality, and external causes of death among men, and breast cancer among women. In the study of mortality until the end of follow-up, some additional associations were found among women between night work and all-cause and preventable mortality, and suicide, suggesting long-term or delayed exposure effects. The study may, however, be underpowered to detect all the exposure-outcome associations, especially among women. More research and prevention are needed to reduce mortality among shift and night workers.

Psychosocial factors at work from the job strain model and preventable mortality in France: The STRESSJEM prospective study.

The study aimed to explore the prospective associations between psychosocial factors at work from the job strain model and preventable mortality, including smoking- and alcohol-related mortality as well as external causes of death. The study was based on prospective data and relied on a sample of 1,511,456 individuals for which data on job history, mortality and causes of death were linked over the 1976-2002 period. Exposures were the factors from the job strain model imputed through a job-exposure matrix. Various time-varying measures of exposure were used including current exposure and two measures of cumulative exposure. Preventable mortality was defined using the OECD/Eurostat list of preventable causes of death. The associations between exposures and outcomes were studied using Cox proportional hazards models. Effect modification by gender was also assessed. Over the study period, 57,264 preventable deaths occurred before the age of 75 years. Low decision latitude, low social support, job strain, iso-strain, passive job, and high strain were associated with preventable mortality, and associations of stronger magnitude were found for job strain and isostrain among men. Stronger associations were observed for alcohol-related mortality than for smoking-related mortality and external causes of death. The fractions of preventable mortality attributable to current exposure to job strain and isostrain were significant among men only (5.1% and 3.3%). Psychosocial factors at work from the job strain model may play a role on preventable mortality. Intensifying research and prevention towards the psychosocial work environment may be helpful to reduce risky health-related behaviours and related mortality.

Psychosocial Work Factors of the Job Strain Model and All-Cause Mortality: The STRESSJEM Prospective Cohort Study.

OBJECTIVE: The objectives were to examine the prospective associations between psychosocial work factors of the job strain model and all-cause mortality in a national representative cohort of French employees using various measures of time-varying exposure. METHODS: The study was based on a sample of 798,547 men and 697,785 women for which data on job history from 1976 to 2002 were linked to mortality data from the national death registry. Psychosocial work factors from the validated job strain model questionnaire were imputed using a job-exposure matrix. Three time-varying measures of exposure were explored: current, cumulative, and recency-weighted cumulative exposure. Cox proportional hazards models were performed to study the associations between psychosocial work factors and mortality. RESULTS: Within the 1976-2002 period, 88,521 deaths occurred among men and 28,921 among women. Low decision latitude, low social support, job strain, isostrain, high strain, and passive job were found to be risk factors for mortality. The model using current exposure was the best relative-quality model. The associations of current exposure to job strain and mortality were found to have hazard ratios of 1.30 (95% confidence interval [CI] = 1.24-1.36) among men and 1.15 (95% CI = 1.06-1.25) among women. The population fractions of mortality attributable to job strain were 5.64% (95% CI = 4.56%-6.71%) among men and 4.13% (95% CI = 1.69%-6.71%) among women. CONCLUSIONS: This study supports the role of the psychosocial work factors of the job strain model on all-cause mortality. Preventive intervention to improve the psychosocial work environment may help to prevent mortality in working populations.

Psychosocial work exposures of the job strain model and cardiovascular mortality in France: results from the STRESSJEM prospective study.

Objectives The study aims to explore the prospective associations of the psychosocial work exposures of the job strain model with cardiovascular mortality, including mortality for ischemic heart diseases (IHD) and stroke, using various time-varying exposure measures in the French working population of employees. Methods The study was based on a cohort of 798 547 men and 697 785 women for which job history data from 1976 to 2002 were linked to mortality data and causes of death from the national death registry. Psychosocial work exposures from the validated job strain model questionnaire were assessed using a job-exposure matrix (JEM). Three time-varying measures of exposure were studied: current, cumulative, and recency-weighted cumulative exposure. Cox proportional hazards models were used to examine the associations between psychosocial work exposures and cardiovascular mortality. Results Within the 1976-2002 period, there were 19 264 cardiovascular deaths among men and 6181 among women. Low decision latitude, low social support, job strain, iso-strain, passive job, and high strain were associated with cardiovascular mortality. Most of these associations were also observed for IHD and stroke mortality. The comparison between the different exposure measures suggested that current exposure may be more important than cumulative (or past) exposure. The population fractions of cardiovascular mortality attributable to job strain were 5.64% for men and 6.44% for women. Conclusions Psychosocial work exposures of the job strain model may play a role in cardiovascular mortality. The estimated burden of cardiovascular mortality associated with these exposures underlines the need for preventive policies oriented toward the psychosocial work environment.

Prospective associations of psychosocial work exposures with mortality in France: STRESSJEM study protocol.

INTRODUCTION: Although evidence has been provided on the associations between psychosocial work exposures and morbidity outcomes in the literature, knowledge appears much more sparse on mortality outcomes. The objective of STRESSJEM is to explore the prospective associations between psychosocial work exposures and mortality outcomes among the national French working population. In this paper, we describe the study protocol, study population, data sources, method for exposure assessment, data analysis and future plans. METHODS AND ANALYSIS: Data sources will include: the data from the national SUMER survey from DARES on the evaluation of psychosocial work exposures and the data from the COSMOP programme from Santé publique France linking job history (DADS data from INSEE) and mortality according to causes of death (data from the national death registry, INSERM-CépiDc). A sample of 1 511 456 individuals will form the studied prospective cohort for which data are available on both job history and mortality over the period 1976-2002. Psychosocial work exposures will be imputed via a job-exposure matrix using three job title variables that are available in both the SUMER and COSMOP data sets. Our objectives will be to study the associations between various psychosocial work exposures and mortality outcomes. Psychosocial work exposures will include the job strain model factors as well as other psychosocial work factors. Various measures of exposure over time will be used. All-cause and cause-specific mortality will be studied. ETHICS AND DISSEMINATION: Both the SUMER survey and the COSMOP programme have been approved by French ethics committees. Dissemination of the study results will include a series of international peer-reviewed papers and at least one paper in French. The results will be presented in national and international conferences. This project will offer a unique opportunity to explore mortality outcomes in association with psychosocial work exposures in a large national representative sample of the working population.

Contribution of working conditions to occupational inequalities in depressive symptoms: results from the national French SUMER survey.

OBJECTIVES: Social inequalities in mental health have been observed, but explanations are still lacking. The objectives were to evaluate the contribution of a large set of psychosocial work factors and other occupational exposures to social inequalities in mental health in a national representative sample of employees. METHODS: The sample from the cross-sectional national French survey SUMER 2010 included 46,962 employees: 26,883 men and 20,079 women. Anxiety and depression symptoms were measured using the Hospital Anxiety and Depression scale. Occupation was used as a marker of social position. Psychosocial work factors included various variables related to the classical job strain model, psychological demands, decision latitude, social support, and other understudied variables related to reward, job insecurity, job promotion, esteem, working time/hours, and workplace violence. Other occupational exposures of chemical, biological, physical, and biomechanical nature were also studied. Weighted age-adjusted linear regression analyses were performed. RESULTS: Occupational gradients were found in the exposure to most psychosocial work factors and other occupational exposures. Occupational inequalities were observed for depressive symptoms, but not for anxiety symptoms. The factors related to decision latitude (and its sub-dimensions, skill discretion, and decision authority), social support, and reward (and its sub-dimensions, job promotion, job insecurity, and esteem) contributed to explain occupational inequalities in depressive symptoms. Decision latitude played a major role in the explanation. Workplace violence variables contributed among men only. Other exposures of physical and biomechanical nature also displayed significant contributions. CONCLUSIONS: Comprehensive prevention policies at the workplace may help to reduce social inequalities in mental health in the working population.

What the French working conditions surveys tell us.

Since 1978, France's Ministry of Labour and the National Statistical Institute (INSEE) have carried out four large-scale sample surveys on working conditions among approximately 20,000 workers, questioned by survey-takers at home, that provide invaluable descriptive information on how work is changing. The last survey published was from 1998, and the 2005 survey is being processed at the time of writing. Taking a lead from this example among others, the European Commission tasked the European Foundation for the Improvement of Living and Working Conditions to carry out similar surveys in EU countries in 1990, 1995, 2000, and now 2005. Between them, these surveys portray an alarming situation where workers are seeing their working conditions getting worse. Another survey using a different methodology, carried out by occupational doctors during health checks on 50,000 workers--the Sumer survey, from the French acronym for the health risk screening program--done for the Ministry of Labour in 1994 and 2003, points to the same general trends. In both France and the broader European Union (EU), physical demands and risks are not lessening, mental workload is growing, working hours are more diverse and less regular, work paces more demanding, compressed deadlines reduce job predictability and task discretion. . . . But at the same time, workers report having more leeway in discharging responsibilities that have expanded due to the rise in skill levels and new forms of work organization.