Article History
Received: 11 March 2019
Accepted: 27 March 2019
First Online: 8 April 2019
Compliance with ethical standards
:
: Erik van Werkhoven declares that he has no conflict of interest. Parvin Tajik declares that she has no conflict of interest. Patrick M. Bossuyt declares that he has no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
Free to read: This content has been made available to all.