Received: 27 February 2018
Accepted: 8 May 2018
First Online: 25 May 2018
Ethics approval and consent to participate
: The local Ethics Committees of Heidelberg and Luebeck approved the study (reference number S-200/2013, and AZ: 16-192). Participants provided written informed consent.
: SB developed the K-BILD. All other authors declare no competing interests.
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