Received: 10 September 2018
Accepted: 29 April 2019
First Online: 17 May 2019
Ethics approval and consent to participate
: Approval for this study was granted by the Human Research Ethics Committee of the Canton Vaud (protocol #2016-00768). Written informed consent was obtained from all participants and all methods were carried out in accordance with the recommendations of the Human Research Ethics Committee of the Canton Vaud and the Declaration of Helsinki.
: Not applicable
: The authors declare that they have no competing interests.