Ethics Statement
This study received approval from the local Ethics Committee (Comité de Protection des Personnes Est-II, Besançon) on November 4th, 2014 and from the French advisory committee on information processing research in the field of health (Comité Consultatif sur le Traitement de l’Information en Matière de Recherche dans le Domaine de la Santé, CCTIRS) (protocol number 15.022-bis) on March 5th, 2015. Approval from the National authority for the protection of privacy and personal data (Commission Nationale Informatique et Libertés, CNIL) was obtained on June 23rd, 2015. Authors had full access to all data in the study, reviewed this manuscript and accepted responsibility to submit for publication.