Funding for this research was provided by:
Deutsche Rheuma-Liga Bundesverband e.V. (NA)
Received: 24 June 2019
Accepted: 16 August 2019
First Online: 29 August 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the Ethics Committee of the Charité University Medicine, Berlin.
: Not applicable.
: The authors declare that they have no competing interests.