1. Université Bordeaux Segalen, ISPED; Inserm Research Center U897, F33076 Bordeaux, France
2. INSERM, ISPED; Centre INSERM U897-Epidémiologie-Biostatistique, F-33000 Bordeaux, France
3. Department of Biostatistics; University of Copenhagen, DK-1014 Copenhagen K, Denmark
4. INSERM, Centre INSERM U1061; Université Montpellier 1, Montpellier, France