Acknowledgements
We appreciate Elke Bandelin, Angelika Beyer, Christian Goeze, Katja Haberecht, Kornelia Sadewasser, Inga Schnuerer and Stefanie Tobschall for their valuable contributions to the project PECO. We are grateful for the support provided by the heads and staff of the participating departments at the University Medicine Hospital Greifswald. We are much obliged to the participants and their efforts to continue participation over two years.