1. INSERM U 1198, Montpellier, France; University of Montpellier, Montpellier, France; and École Pratique Des Hautes Études, Paris, France
2. Department of Epidemiology and Public Health, University College London, London, U.K.
3. 1st Department of Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary
4. Department of Medical Information, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
5. INSERM U 1018, Paris, France
6. School of Social and Community Medicine, University of Bristol, Bristol, U.K.