OBJECTIVE: To test whether psychosocial factors at work are predictors of rates of sickness absence.
METHODS: The study population consisted of middle aged men and women employed by the French national electricity and gas company (EDF-GDF) in various occupations and followed up since 1989 by annual self administered questionnaires and independent data obtained from the medical and personnel departments of EDF-GDF. The 1995 questionnaire provided information about three psychosocial work factors: psychological demands, decision latitude, and social support at work. Sick-ness absence data were provided by the company's social security department. The occurrence of spells and days of absence in the 12 months after completion of the 1995 questionnaire was studied. Potential confounding variables were age, smoking, alcohol, and marital status, assessed in the 1995 questionnaire, and educational level and occupation, assessed from data provided by the personnel department. This study was restricted to the 12,555 subjects of the initial cohort who were still working and answered the self administered questionnaire in 1995.
RESULTS: Low levels of decision latitude were associated with more frequent and longer sickness absences among men and women. Low levels of social support at work increased the numbers of spells and days of absence among men only. These associations weakened after adjustment for potential confounding factors, but remained significant.
CONCLUSION: The study indicates that psychosocial factors at work, especially decision latitude, are predictive of sickness absence.
OBJECTIVE: This study attempted to establish whether psychosocial factors at work are predictors of depressive symptoms in a prospective cohort of men and women employed in a wide variety of occupations by the French national company Electricité De France - Gaz De France (EDF-GDF).
METHODS: This prospective cohort study followed the Gazel cohort by means of annual self-administered questionnaires and independent data obtained from the medical and personnel departments of the company. The self-administered questionnaire, in 1995, provided information about the psychosocial work environment characteristics, psychological job demands, decision latitude, and social support at work. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression (CES-D) Scale in the 1996 questionnaire. Potential confounding variables were age, marital status, and number of children, assessed in the 1995 questionnaire, stressful personal and occupational events during the previous 12 months, assessed in the 1996 questionnaire, and educational level, occupation and previous absenteeism for mental disorders, assessed from the independent data provided by EDF-GDF. The subjects were 11 552 workers (8422 men aged 46-56 years in 1995 and 3130 women aged 41-56 years) who answered the 1995 and 1996 questionnaires and were working during this period.
RESULTS: High levels of psychological demands, low levels of decision latitude, and low levels of social support at work were significant predictors of subsequent depressive symptoms in both the men and the women. These results were unchanged after adjustment for potential confounding variables.
CONCLUSIONS: The results strongly support the possibility that psychosocial factors at work are predictive of depressive symptoms.
The objectives of this prospective study were to identify predictive factors for sick leave of 8 days or more due to low back pain (LBSL) and to compare them with predictive factors for low back pain with no or shorter sick leave (LB) in a cohort of French workers. The predictive factors for LBSL were a past history of low back pain (odds ratio [OR], 7.2; 95% confidence interval [CI], 4.1 to 13), a low employment grade (OR, 4.3; 95% CI, 1.7 to 11), heavy smoking (OR, 5.5; 95% CI, 2.3 to 13), a pain score different from zero (OR, 4.9; 95% CI, 2.5 to 9.7), required bending backward or forward at work every day repetitively (OR, 7.4; 95% CI, 2.3 to 23), overall social integration (OR, 2.0; 95% CI, 1.3 to 3.3), and low social support at work (OR, 3.4; 95% CI, 1.6 to 7.3). Low social support at work and bending backward or forward at work were more strongly associated with LBSL than with LB (P = 0.02 and P < 0.01, respectively). The implications of the results of this prospective study are that both the level of biomechanical exposure and the psychosocial work environment, especially social support, represents important dimensions to consider in the reduction of work absenteeism.
The GAZEL Cohort Study was set up in 1989 among Électricité de France-Gaz de France (EDF-GDF) workers. It is an open epidemiologic laboratory characterized by a broad coverage of health problems and determinants and accessible to the community of researchers. At inception in 1989, the GAZEL Cohort Study included 20625 volunteers working at EDF-GDF then aged from 35 to 50 years (15011 men and 5614 women). The cohort is broadly diverse in terms of social, economic, and occupational status, health, and health-related behavior. The data collected routinely cover diverse dimensions and come from different sources: annual self-administered questionnaire (morbidity, lifestyles, life events, etc.); personnel department of EDF-GDF for social, demographic, and occupational characteristics; EDF-GDF Special Social Insurance fund (for sickness absences and cancer and ischemic heart disease registries), occupational medicine (occupational exposure and working conditions), Social Action Fund (healthcare utilization), Health Screening Centers for standardized health examination and the constitution of a biobank, and the National Death Register (causes of death). Follow-up has been excellent, and the number of subjects lost to follow-up was exceptionally low; active participation by the self-administered questionnaire is also elevated. Today, more than 40 projects on diversified themes have been set up in the GAZEL Cohort Study by some 30 French and foreign teams. Different health problems taking into account behavioral, social, psychological and medical occupational risk factors have been the object of research projects in the cohort. A substantial proportion of the research work has focused on social inequalities in health. Here, we present a brief panorama of the main fields covered by research in the GAZEL Cohort Study that have already been published over the years.
BACKGROUND: The objectives of this prospective study were to investigate personal and occupational predictors of sciatica and to compare the risk factors for sciatica and those for low back pain without sciatica.
METHODS: The study analysed data from 841 men, initially free from low back pain, who were followed for 2 years. Subjects were participants in the French GAZEL cohort of employees of the national electricity and gas company. The predictive factors for sciatica and low back pain without sciatica were compared with a polytomous model.
RESULTS: Height and driving were predictors only for sciatica, and bending forward and backward at work was a predictor only for low back pain without sciatica. The odds ratio (OR) for sciatica associated with 'height >180 cm' was 3, with a 95% confidence interval (CI) of 1.4-6.5; for driving >2 h daily it was 2 (CI = 0.94-4.10) and for driving >2 h several days a week 2.7 (CI = 1.20-6.10).
CONCLUSION: This study confirmed that height and driving are risk factors for sciatica and that sciatica has specific predictors different from those for other types of low back pain. Future studies should consider sciatica separately from these.
OBJECTIVES: To estimate the contribution of stress-related and physical work factors to occupational class disparities in sickness absence from work.
METHODS: Our sample consisted of 8847 men and 2886 women participating in the French GAZEL cohort study. Occupational class and medically certified sickness absence data (1995-2001) were obtained from the participants' employer. Work characteristics (physical and stress-related) were self-reported. We calculated rate ratios with Poisson regression models; fractions of sickness absence attributable to work factors were estimated with the Miettinen formula.
RESULTS: Sickness absence was distributed along an occupational gradient. Work characteristics accounted for 19% (women) and 21% (men) of all absences. Physical work conditions accounted for 42% and 13% of absences for musculoskeletal reasons, and work stress accounted for 48% and 40% of psychiatric absences. Overall, about 20% of the occupational class gradient in sickness absence could have been associated with deleterious work conditions.
CONCLUSION: Work conditions contribute to sickness absence, particularly among manual workers and clerks. Policies that decrease ergonomic constraints and work stress also could reduce the burden of ill health and sickness absence among the lowest strata of working populations.
OBJECTIVE: To estimate obstetric risk factors of fecal incontinence among middle-aged women. METHODS: We conducted a mail survey of the Gazel cohort of volunteers for epidemiologic research. In 2000, a questionnaire on anal incontinence was mailed to 3,114 women who were then between the ages of 50 and 61 years; 2,640 (85%) women returned the completed questionnaire. Fecal incontinence was defined by involuntary loss of stool. Logistic regression was used to estimate the effect of obstetric and general risk factors. RESULTS: Prevalence of fecal incontinence in the past 12 months was 9.5% (250). Significant risk factors for fecal incontinence were completion of high school (adjusted odds ratio [OR] 1.5, 95% confidence interval [CI] 1.1-2.0), self-reported depression (OR 2.1, 95% CI 1.6-2.7), overweight or obesity measured by body mass index (BMI) (OR 1.5 for BMI of 25-30, 95% CI 1.1-2.0; OR 1.6 for BMI more than 30, 95% CI 1.1-2.5), surgery for urinary incontinence (OR 3.5, 95% CI 2.0-6.1), and anal surgery (OR 1.7, 95% CI 1.1-2.9). No obstetric variable (parity, mode of delivery, birth weight, episiotomy, or third-degree perineal tear) was significant. Prevalence of fecal incontinence was similar for nulliparous, primiparous, secundiparous, and multiparous women (11.3%, 9.0%, 9.0%, and 10.4%, respectively), and among parous women, it was similar for women with spontaneous vaginal, instrumental (at least one), or only cesarean deliveries (9.3%, 10.0%, and 6.6%, respectively). CONCLUSION: In our population of women in their 50s, fecal incontinence was not associated with either parity or mode of delivery.
OBJECTIVE: To assess the effects of duration of exposure to biomechanical strains on various types of low back pain (LBP).
METHODS: The population study was a random sample from the GAZEL cohort. Durations of exposure to selected biomechanical strains during subjects' working lifetime and potential confounders were assessed in 1996 by self-administered questionnaires. Data on LBP in the previous 12 months were collected in 2001. Relations between various dimensions of LBP and durations of exposure to the biomechanical strains were analysed with multivariate regression models. Polytomous models were built to determine whether some biomechanical strains were specifically associated with some types of LBP.
RESULTS: Analyses were performed separately for men (n = 2218) and women (n = 383). Significant associations were observed (ORs reported are those for 20 years of exposure) between LBP and durations of driving and bending/twisting for men (OR 1.24 and 1.37 respectively); LBP for more than 30 days and duration of exposure to bending/twisting for men and women (OR 2.20 and 2.00 respectively) and duration of driving for women (OR 3.15); LBP radiating to the leg and duration of driving for men (OR 1.43) and bending/twisting for women (OR 1.95); LBP radiating below the knee and duration of exposure to pulling/pushing/carrying for men (OR 1.88). Bending/twisting in both men and women, and driving for women appeared to be stronger risk factors for LBP for more than 30 days. Pulling/pushing/carrying heavy loads appeared to be a risk factor specific for LBP radiating below the knee for men.
CONCLUSION: This study suggests that exposure to biomechanical strains has long-term effects and a dose-response relation with duration of exposure and specific effects for some types of LBP.
OBJECTIVE: To analyze the role that biomechanical strains and psychosocial work factors play in occupational class disparities in low-back pain in the GAZEL cohort.
METHODS: Recruited in 1989, the GAZEL cohort members were employees of the French national company in charge of energy who volunteered to enroll in an annual follow-up survey. The study population comprised 1487 men who completed questionnaires in 1996 (past occupational exposure to manual material handling, bending/twisting, and driving), 1997 (psychosocial work factors), and 2001 (low-back pain using a French version of the Nordic questionnaire for the assessment of low-back pain). Associations between low-back pain for >30 days in the preceding 12 months and social position at baseline (four categories) were described with a Cox model to determine prevalence ratios for each category. We compared adjusted and unadjusted ratios to quantify the contribution of occupational exposures.
RESULTS: The prevalence of low-back pain for >30 days was 13.6%. The prevalence of low-back pain adjusted for age was significantly higher for blue-collar workers and clerks than for managers. The number of socioeconomic disparities observed was significantly reduced when biomechanical strains were taken into account; adjusting for psychosocial factors had little impact.
CONCLUSION: In this population, occupational exposures--especially biomechanical strains--played an important role in occupational class disparities for persistent or recurrent low-back pain.
BACKGROUND: Data on the association between dietary patterns and depression are scarce. The objective of this study was to examine the longitudinal association between dietary patterns and depressive symptoms assessed repeatedly over 10 years in the French occupational GAZEL cohort.
METHODS: A total of 9,272 men and 3,132 women, aged 45-60 years in 1998, completed a 35-item Food Frequency Questionnaire (FFQ) at baseline. Dietary patterns were derived by Principal Component Analysis. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression scale (CES-D) in 1999, 2002, 2005 and 2008. The main outcome measure was the repeated measures of CES-D. Longitudinal analyses were performed with logistic regression based on generalized estimating equations.
PRINCIPAL FINDINGS: The highest quartile of low-fat, western, high snack and high fat-sweet diets in men and low-fat and high snack diets in women were associated with higher likelihood of depressive symptoms at the start of the follow-up compared to the lowest quartile (OR between 1.16 and 1.50). Conversely, the highest quartile of traditional diet (characterized by fish and fruit consumption) was associated with a lower likelihood of depressive symptoms in women compared to the lowest quartile, with OR = 0.63 [95%CI, 0.50 to 0.80], as the healthy pattern (characterized by vegetables consumption) with OR = 0.72 [95%CI, 0.63 to 0.83] and OR = 0.75 [95%CI, 0.61 to 0.93] in men and women, respectively. However, there was probably a reverse causality effect for the healthy pattern.
CONCLUSION: This longitudinal study shows that several dietary patterns are associated with depressive symptoms and these associations track over time.
To test whether psychosocial factors at work are predictors of rates of sickness absence.
METHODS:
The study population consisted of middle aged men and women employed by the French national electricity and gas company (EDF-GDF) in various occupations and followed up since 1989 by annual self administered questionnaires and independent data obtained from the medical and personnel departments of EDF-GDF. The 1995 questionnaire provided information about three psychosocial work factors: psychological demands, decision latitude, and social support at work. Sick-ness absence data were provided by the company's social security department. The occurrence of spells and days of absence in the 12 months after completion of the 1995 questionnaire was studied. Potential confounding variables were age, smoking, alcohol, and marital status, assessed in the 1995 questionnaire, and educational level and occupation, assessed from data provided by the personnel department. This study was restricted to the 12,555 subjects of the initial cohort who were still working and answered the self administered questionnaire in 1995.
RESULTS:
Low levels of decision latitude were associated with more frequent and longer sickness absences among men and women. Low levels of social support at work increased the numbers of spells and days of absence among men only. These associations weakened after adjustment for potential confounding factors, but remained significant.
CONCLUSION:
The study indicates that psychosocial factors at work, especially decision latitude, are predictive of sickness absence.
