Received: 28 February 2017
Accepted: 29 January 2018
First Online: 7 February 2018
: The authors have the necessary regulatory agreements to use the patient data from the National Commission on Informatics and Liberty (CNIL), aimed at ensuring the application of data privacy laws. (CNIL authorisation number DR-2012-038).
: Not applicable
: The authors declare that they have no competing interests.
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