The original GAZEL cohort was composed of 20,625 employees of the French national gas and electricity companies (15,011 male employees then aged 40 to 50 years and 5,614 women between 35 and 50 years old) at its inception in 1989.

Follow-up is continuous and includes data collection on health status, lifestyle, and socioeconomic and occupational factors from various sources. A postal questionnaire is sent to the participants each year, and data are extracted regularly from the files of the personnel and medical departments of EDF-GDF and from national registers. Participants were invited in 1999-2000, 2008 and 2011 to a health clinic where medical and biological data were collected.

The main focus of research in the past decade was devoted to the study of the persistent, long-term effects of occupational exposures after retirement; of the transition between professionally active life and retirement; and on determinants of early ageing. Accordingly, in addition to the health, behavioural and social data collected yearly since the beginning of the follow-up, new data were thus collected on cognitive complaints, cognitive and physical functioning, limitations in daily activities, time use and social relationships of retirees.

Last update – 20/06/2017

The CONSTANCES general-purpose cohort is intended to serve as an epidemiological research infrastructure accessible to the epidemiologic research community with a focus on chronic diseases and aging. CONSTANCES is designed as a randomly selected representative sample of French adults aged 18-69 years at inception; 200,000 subjects will be included over a five-year period. At inclusion, the selected subjects are invited to complete questionnaires and to attend a Health Screening Clinic (HSC) for a comprehensive health examination. A biobank will be set up. The follow-up includes a yearly self-administered questionnaire, and a periodic visit to an HSC. Social and health data are collected from the French national databases. Data collected for participants include social and demographic characteristics, socioeconomic status, life events, behaviors, and occupational factors. The health data cover a wide spectrum: self-reported health scales, reported prevalent and incident diseases, long-term chronic diseases and hospitalizations, sick-leaves, handicaps, limitations, disabilities and injuries, healthcare utilization and services provided, and causes of death. To take into account non-participation at inclusion and attrition throughout the longitudinal follow-up, a cohort of non-participants was set up and will be followed through the same national databases as participants.

Last update – 20/06/2017