Funding for this research was provided by:
Royal Society of Edinburgh (none existent)
Landeszentrum Gesundheit Nordrhein-Westfalen (none existent)
Text and Data Mining valid from 2020-03-31
Received: 18 December 2019
Accepted: 12 March 2020
First Online: 31 March 2020
Ethics approval and consent to participate
: This study received ethical approval from the Ethics Committee of the Medical Faculty of the University of Cologne. Written informed consent was obtained from all study participants.
: Not applicable, since no individual data of the participants is being published.
: Holger Pfaff is a member of the editorial board of BMC Health Services Research.