In November 2022, the Constances cohort celebrated its tenth anniversary. The opportunity to review the great scientific advances that it has allowed but also to recall the interest of this type of infrastructure for biomedical research and more broadly for society.
An article to be found in the magazine ofInserm n°56
“A cohort is a survey that individually follows a group of people “Explains from the outset Marie Zins, director of the population epidemiological cohorts service unit, in Villejuif. If the cohorts of patients are centered on a pathology, those in population, like Constances, are interested in health in general. Although generalist, the Constances cohort is unique in its size. ” From the start, we targeted the very exclusive club of megacohorts “recalls Marie Zins. With its 220,000 volunteers, sick or not, aged 18 to 69 on inclusion, Constances represents the largest epidemiology and public health research project in France. This sample, aimed at being representative of the adult population in mainland France, constitutes an extremely detailed source of information.
Indeed, all the volunteers undergo, during their inclusion and then every four years, a complete health examination: physical, auditory, visual, pulmonary, biological but also cognitive measurements from the age of 45… “ For more than a quarter of the participants, we were able to collect blood and urine, adds the cohort leader. That is a total biobank of 1,400,000 samples. These objective data are supplemented each year by questionnaires: pathologies, diet, physical activity, consumption of alcohol and tobacco, etc. Recurring items to which are added other, occasional themes, depending on the projects in progress: asthma and rhinitis, exposure to pesticides, molds and household products… The list is long! commented Marie Zins. Last significant source of information: the administrative bases. From the outset, Constances has been linked to the National Health Data System (SNDS), which includes healthcare reimbursements, long-term illnesses, hospitalizations, accidents at work and causes of death. ” It is also the only cohort in France coupled with the basics of old-age insurance, which trace the entire social and professional trajectory of volunteers. », Rejoices the epidemiologist.
The quantity, quality and variety of pseudonymised data collected make it possible to study the role – even weak – of biological, genetic or environmental agents in certain pathologies. ” The value of a cohort increases with time and the occurrence of health “incidents”explains Marie Zins. Constances is only at the very beginning of what she can teach us. »
Informing public policies
Thanks to the projects completed or in progress (to date 130, including a large number submitted by Inserm), we now know that:
- SARS-CoV-2 was circulating in France from the first week of November 2019 (F. Carrat et al. Eur J Epidemiol., February 6, 2021 ) ,
- alcohol addiction is about 2.5 times more common among inactive people than among active people (Mildeca, March 2021),
- obstructive ventilatory disorders are under-diagnosed (M.-C. Delmas et al. BMC Pulm Med.October 14, 2021),
- air pollution would increase the risk of cognitive deficit (MJZ Sakhvidi et al. Lancet Planet Health., mars 2022),
- or that one in four French people suffers from a hearing impairment but few of them have hearing aids (Q. Lisan et al. JAMA Network Open.1is June 2022).
« Public authorities are eager to know if the better reimbursement of hearing aids will increase the rate of fitting “says the researcher. The various published results could also lead to the generalization of respiratory tests in city medicine, or to the launch of prevention campaigns targeting addictions, chronic bronchitis, etc.
The data collected – several terabytes – is also accessible: “ The scientific community can take over and, under certain conditions, submit new questions or examinations to the volunteers », explains Marie Zins. The activity of the cohort is therefore constantly enriched, with more than 190 researchers from all walks of life (Europe, Canada, United States, etc.).
Since January, Olivier Laurent, researcher at the Institute for Radiation Protection and Nuclear Safety (IRSN), has been leading the Corale project on ionizing, carcinogenic radiation. Via a questionnaire and various administrative databases, it lists the environmental, medical and professional exposure, since birth, of 80,600 volunteers who declared their residential history. Data that he will complete with radon measurements on 1,000 of them. Objective ? Assess the effects, often delayed, of low radioactivity on non-cancerous pathologies and the interactions with other risk factors.
In 2023, 2,000 saliva samples will also be sequenced under the leadership of Emmanuelle Génin, winner of the 2017 Inserm Research Prize and Director of the Genetics Unit, genomics functional and biotechnologies in Brest. The genetic variations detected in the DNA will make it possible to improve the diagnosis of certain diseases. Another novelty: Alban Redheuil, head of cardiovascular imaging at the Pitié-Salpêtrière hospital in Paris, is launching the Iconic project with the MSD Avenir foundation with 2,400 volunteers in the Ile-de-France region. ” Constances will thus become the first French population imaging cohort in multimodality (ultrasound and MRI) studying the heart, vessels, liver and fat tissue with the latest technologies and including the under 40s to visualize the processes of aging », Details Marie Zins. A world first! Other innovations are being prepared with private partners, for example digital twins of patients in order to choose ” for each individual the right treatment at the right time “. In this ecosystem, respect for health data takes precedence. The association of volunteers Constances, created in June 2020 – an unprecedented initiative in the world – has thus worked to ensure that SNDS data remains in Europe. Sensitive data from Constances is managed in France at the Secure Data Access Center (CASD).
Voluntary and proud of it
The primary mission of the association is, however, to make the link between the work of the cohort and the volunteers, scattered throughout France, so that they understand the usefulness of their civic participation, enlightens its president, Frédérique Anne. We are not an association of patients who have an immediate interest in the results of research. Apart from medical examinations, the contribution of Constances for each individual only appears through the evolution of public health policies. »
To further improve the quantity and quality of data, and in fine research and funding opportunities, it is essential to mobilize the 220,000 individuals included for the entire legal period of use of the data, ie 30 years or more! In addition to its communication actions to promote the participants, the Constances association is therefore thinking about the questionnaires in order to increase the response rates: ” 80% have already answered at least one questionnaire, but “only” 57% have completed them all “, illustrates the president. The association has also recently embarked on a participatory approach: members prepare a summary of publications in health and environment backed by Constances to identify new research questions. Thanks to their regular exchanges with researchers, they contribute to advancing science, together.
Marie Zins is director of the Population epidemiological cohorts service unit (mixed service unit 11 Inserm/Paris Cité University, Paris Saclay University, University of Versailles-Saint-Quentin-en-Yvelines) in Villejuif.