1. Institute of Primary and Community Care, Lucerne, Switzerland.
2. Swiss Paraplegic Research, Nottwil, Switzerland.
3. Department of Psychosomatic Medicine, Division of Internal Medicine, University Hospital Basel, Basel, Switzerland.
4. Division of Oncology/Hematology, University Children's Hospital, Basel, Switzerland.
5. Department of Pediatrics II, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.