He was Director of the Biostatistics Laboratory at the University of Paris 7 (1974-1981), the Inserm Research Unit 263 "Biomathematics and Biostatistics" (1981-1995), the Cooperative Data Centre on the Epidemiology of Human Immunodeficiency (1988-1991), the Inserm Research Unit 444 "Epidemiology and Information Sciences" from 1995 to 2004.