Funding for this research was provided by:
Institut de Veille Sanitaire (not applicable)
Received: 20 September 2018
Accepted: 18 June 2019
First Online: 27 June 2019
Ethics approval and consent to participate
: We performed an observational study on anonymous data. Under French law, this does not require approval by a regulatory structure or an ethics committee (law decree). The protocol was conducted in agreement with the Helsinki Declaration and obtained authorization from the French Data Protection Agency (CNIL, registration 471393).
: Not applicable.
: The authors declare that they have no competing interests.