La construction d'une cohorte : l'expérience du projet français Elfe

The project to construct a multidisciplinary study cohort of 20,000 children to be monitored from birth to adulthood was launched in France in 2005. It was designed to address the concerns of various public bodies, especially those concerned with the environment, and researchers from a variety of disciplines. The result was the formation of the Elfe (Étude longitudinale française depuis l?enfance) longitudinal cohort of children, scheduled to commence in March/April 2011. The authors describe the origins of the project. The approach was deliberately intended to be multidisciplinary, and a large number of research teams were associated in designing the project, suggesting research questions in three major fields: social sciences, health and the links between health and the environment. To make the most of the life course approach, observations will be frequent (annually during the early years). A major place is given to fathers, who play an increasing role in children?s upbringing and socialization. The sample will be representative of births in 2011 throughout metropolitan France. The vast quantity of information to be collected and its highly personal nature require particular caution in the creation and management of data files, for which an innovative procedure will be used. The results of a pilot cohort study launched in 2007 are also presented. They cover several hundred families, whose children are now three years old.