Text and Data Mining valid from 2020-03-23
Received: 11 January 2020
Accepted: 7 March 2020
First Online: 23 March 2020
Ethics approval and consent to participate
: All participants gave their informed consent, and this study was performed in compliance with the Helsinki Declaration, and was approved by the local Ethics Committee.
: Not applicable.
: The authors declare that they have no competing interests.