1. Department of Nephrology and Hypertension, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland
2. Centre for Investigation and Research in Sleep (CIRS), University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland
3. Hemodialysis Unit, Northern Vaud Hospital, 1400 Yverdon, Switzerland
4. Hemodialysis Unit, Broye Intercantonal Hospital, 1530 Payerne, Switzerland
5. Hemodialysis Unit, EHC Hospital, 1110 Morges, Switzerland
6. Hemodialysis Unit, Riviera Providence Hospital, 1800 Vevey, Switzerland
7. Hemodialysis Unit, Cecil Clinic, 1011 Lausanne, Switzerland