Received: 16 January 2019
Accepted: 9 July 2019
First Online: 18 July 2019
Ethics approval and consent to participate
: The study was approved by Swissethics Zurich (Swissethics, CitationRef removed.; Kantonale Ethikkommission Zürich, CitationRef removed). EC-No.: 2015–0152.
: Written informed consent was obtained from all individual participants included in the study.
: The authors declare that they have no competing interests.