Ethics approval and consent to participate
This study was conducted in compliance with the principles of the Declaration of Helsinki. The institutional ethical review board (IRB) of Charité Universitätsmedizin Berlin (processing number EA1/093/16) granted its approval for this trial at June 2, 2016. The IRB granted a waiver of written informed consent as the study fulfilled all criteria of a cluster-randomised controlled trial (cRCT).