The French GAZEL Cohort Study: 20 years of epidemiologic research

Abstract

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. KEY WORDSEpidemiology, Cohort study, Follow-up, Open Epidemiologic Laboratory THE CONTRIBUTION OF EPIDEMIOLOGIC COHORTS TO KNOWLEDGE ABOUT HEALTHEpidemiology is the scientific discipline that studies the health of populations. Only by epidemiologic methods can we determine the frequency of health problems, their distribution according to diverse criteria (age, sex, occupational and social status, region, etc.), and their course over time. Epidemiology also allows to understand the determinants of health status and of diseases: it is the science that showed the role in numerous health problems of what are now known risk factors  physical and chemical factors such as smoking or asbestos, as well as psychological or socioeconomic factors. Finally epidemiology makes it possible to assess the efficacy of health activities  screening, prevention, and health care utilization.Epidemiology permits a comprehensive approach to health, in all its dimensions, both individual and collective. It is therefore an essential tool for determining health policies, planning health prevention, and assessing health actions.Epidemiology uses different methods; among these, diverse characteristics make cohorts a tool of choice. An epidemiologic cohort is a type of survey based on the principle of longitudinal follow-up of a group of subjects on an individual scale. From the methodological point of view, the principal advantage of cohorts is that they optimize the consideration of different factors related to living conditions (e.g., diet, housing, access to care, and social network), the en...

Influence of retirement and work stress on headache prevalence: A longitudinal modelling study from the GAZEL Cohort Study

“…[24] At baseline, 20,625 employees (73% men), aged 35–50, agreed to participate. EDF-GDF employees hold a civil servant-like status that guarantees job security and opportunities for occupational mobility.…”

“…Because of these characteristics, study follow-up is very thorough and losses to follow-up small. [24]…”

Effects of job strain on fatigue: cross-sectional and prospective views of the job content questionnaire and effort–reward imbalance in the GAZEL cohort

“…The GAZEL cohort has been described extensively elsewhere 29 31. In brief, the study was established in 1989 and surveyed employees of the French National Electricity and Gas Company with 20 625 initial respondents 29.…”

Social engagement across the retirement transition among “young-old” adults in the French GAZEL cohort

“…It remains to be seen whether the experience of this cohort is generalizable to other French men and women in the work force or in other countries. It is important to note; however, that in most other respects, social and economic conditions have been related to health outcomes in the GAZEL cohort in a way consistent with most other occupational cohorts in other industrialized countries (Zins et al 2009). …”