Text and Data Mining valid from 2019-06-07
Received: 15 February 2019
Accepted: 22 May 2019
First Online: 7 June 2019
Ethics approval and consent to participate
: This study was approved by the Medical Ethical Committee of the University Medical Center Groningen (METc 2015/115). All participants gave written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.