[1] University of Duisburg-Essen,Department of Internal and Integrative Medicine
[2] Saarland University Hospital,Department of Anaesthesiology, Intensive Care and Pain Therapy
[3] Klinikum Saarbrücken,Department of Internal Medicine I
[4] Technische Universität München,Department of Psychosomatic Medicine and Psychotherapy
[5] Department of Pain Management,undefined
[6] BG University Hospital Bergmannsheil GmbH,undefined
[7] Ruhr University Bochum,undefined