Ethics approval and consent to participate
The ethics committee of the Charité – Universitätsmedizin Berlin approved this study (EA4/027/15). All procedures were carried out in compliance with the Helsinki Declaration. Before inclusion into the study by PrevOP-MMT medical personnel, written informed consent was obtained from each participant for participation in all study parts (PrevOP-MMT and PrevOP-PAP). Amongst other information, participants were informed: (1) that participation in the study is completely voluntary, (2) that they have the right to withdraw from the trial whenever they desire and that they do not have to state a reason for their decision, (3) that refusal to participate or discontinuation of participation will not have any consequences for the usual care they receive, (4) that their identifying information will be kept strictly confidential (and apart from the remainder of their data), their data being made anonymous by assignment of a pseudonym (i.e., a participant ID-number), (5) that their data will be stored, analyzed, and published in an anonymous form by collaborating study researchers.