Funding for this research was provided by:
German Federal Ministry of Family Affairs, Senior Citizens, Women and Youths (none)
LEO Stiftung (none)
Received: 7 March 2019
Accepted: 24 July 2019
First Online: 22 August 2019
Ethics approval and consent to participate
: The review board of the Charité – Universitätsmedizin Berlin (Ethical Committee II at Campus Virchow Klinikum) approved the study on August 15th, 2012 (reference number EA2/088/12).
: None of the authors declared a competing interest in relation to this manuscript.