Received: 17 June 2019
Accepted: 23 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: The study was reviewed and approved by the Ethics Committee of the Hannover Medical School (No. 7830_BO_K_018). A written consent for audio-video -recording was obtained.
: Not applicable.
: Authors declare that they have no competing interests.