Received: 18 May 2018
Accepted: 23 June 2019
First Online: 23 July 2019
Ethics approval and consent to participate
: The study was approved by the ethics committee of Hannover Medical School (file no. 6775) and conducted in accordance with national law and the Helsinki Declaration (in its current revised form: 64th WMA General Assembly, Fortaleza, Brazil, October 2013). Written informed consent was obtained from all study participants before study assessments were begun. The study was registered on ClinicalTrials.gov (no. NCT02362919) prior to starting.
: Not applicable.
: The authors declare that they have no competing interests.