Received: 30 September 2019
Accepted: 20 May 2020
First Online: 8 June 2020
Ethics approval and consent to participate
: Central ethical approval has been confirmed by Albert Ludwig of University of Freiburg (DRKS00014814), and we will not begin recruiting at other centers in the trial until local ethical approval has been obtained. All participants give their written consent to participate on a voluntary basis and can withdraw from the study at any time without giving reasons and without their decision affecting their medical care.
: Not applicable, because the study does not contain individual data.
: The authors declare that they have no competing interests.