Article History
Received: 28 February 2020
Revised: 27 September 2020
Accepted: 29 September 2020
First Online: 23 November 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: Ethical approval for Survey 2012 was granted by Kantonale Ethikkommission Luzern (internal application 11042, approved 28.06.2011, Commission Cantonale Valaisanne d’Ethique Médicale Sion (internal application CCVEM042/11, approved 06.12.2011), and Ethikkommission Basel (internal application 306/11, approved 06.09.2011). Ethical approval for Survey 2017 was granted by the Ethikkommission Nordwest-und Zentralschweiz (EKNZ, Project-ID = 11042 PB_2016-02608, approved Dec 2016). We certify that all applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research.