Ethics approval and consent to participate
48147
DER
All participants gave their written informed consent to study participation and ethical standards were in accordance with the declaration of Helsinki. The requirement for ethical approval was waived by the Ethics Committee Münster (Ethikkommission der Ärztekammer Westfalen-Lippe und der Westfälischen Wilhelms-Universität Münster, Gartenstraße 210–214, 48147 Münster) because of the retrospective nature of the study.