Funding for this research was provided by:
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (182815)
Received: 29 May 2019
Accepted: 18 July 2019
First Online: 30 July 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Northwestern and Central Switzerland (EKNZ 2017–01451) and complied with the declaration of Helsinki. Written informed consent was obtained from all study participants.
: not applicable.
: The authors declare that they have no competing interests.