[1] CHU A Michallon, Serv Reanimat Med, F-38043 Grenoble, France
[2] INSERM, Dept Epidemiol, U578, F-38043 Grenoble, France
[3] Hop Robert Debre, CIC EC, Unite Epidemiol Clin, F-75019 Paris, France
[4] Hop St Louis, AP HP, Dept Biostat & Informat Med, INSERM,ERM 0321, Paris, France