Constances, the French nationwide population cohort: major accomplishments

The CONSTANCES cohort is an epidemiological research infrastructure accessible to the international epidemiologic research community (doi.org/10.13143/inserm_constances). CONSTANCES also provides public health authorities with data regarding prevalence of numerous health conditions and determinants among the French population. CONSTANCES comprises a representative sample of about 220,000 French adults aged 18-69 at enrolment (7.6% participation rate). Follow-up begins at enrolment and is intended to last for the lifetimes of study participants. At inclusion, the selected subjects completed questionnaires and underwent a comprehensive health examination. A biobank was established. The follow-up includes a yearly self-administered questionnaire, and a health examination every four years. Social and health data are collected continually from French national administrative databases. The data collected cover a wide spectrum of somatic and mental health disorders, social and demographic characteristics, socioeconomic status, life events, behaviors, environmental and occupational factors. In order to estimate prevalences that are unbiased by non-participation, weighting methods based on data from national administrative databases were developed. The CONSTANCES research infrastructure is open to legitimate researchers from any country, on any topic for which a sound research project is proposed, and for which certain ethical conditions are met. Up to 2025, over 200 projects have been conducted and more than 250 papers have been published; the numbers are expected to grow as the participants age. Highlighting the broad scope of CONSTANCES data collection, already published papers pertain to many health research fields, such as chronic diseases, aging, women’s health, environmental and occupational risks or research methods.