Funding for this research was provided by:
SNCF Medical Department
Text and Data Mining valid from 2018-04-16
Received: 24 August 2017
Accepted: 27 March 2018
First Online: 16 April 2018
Ethics approval and consent to participate
: Written informed consent was obtained from participants. The study protocol and data collection were approved by the Data Protection Officer of the French National Railways Company (Correspondant Informatique et Libertés de la Société Nationale des Chemins de Fer Français) under the reference number: D14.022.V.M00.
: Not applicable.
: The authors declare that they have no competing interests.
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