Received: 22 January 2019
Accepted: 25 March 2019
First Online: 13 May 2019
Ethics approval and consent to participate
: Data collection was declared to the French National Committee for the Protection of Data Privacy (CNIL, Comission Nationale de l’Informatique et des Libertés), with restriction to publish aggregated data. As a retrospective observational study design, no authorization from an ethic committee was needed according to French law.
: Not applicable.
: ET, BS, MB, BC, CGJ and LRS report no competing interest.
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