1. Department of Internal Medicine, Faculty of Medicine, University of Patras, University Hospital of Patras, 265 04 Patras, Greece
2. Department of Internal Medicine, General Hospital of Lamia, 351 00 Lamia, Greece
3. 1st Department of Internal Medicine, General Hospital of Athens “G. Gennimatas”, 115 27 Athens, Greece
4. 2nd Department of Internal Medicine, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
5. 3rd Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, General Hospital of Thessaloniki “Papageorgiou”, 564 29 Thessaloniki, Greece
6. Department of Internal Medicine, General Hospital of Athens “Elpis”, 115 22 Athens, Greece
7. 1st Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, 11527 Athens, Greece
8. General Hospital of Eleusis “Thriasio”, 196 00 Athens, Greece
9. Intensive Care Unit, General Hospital for Thoracic Diseases “Sotiria”, 115 27 Athens, Greece
10. 1st University Pulmonology Clinic and ICU, Medical School, National and Kapodistrian University of Athens, General Hospital for Thoracic Diseases “Sotiria”, 115 27 Athens, Greece
11. Department of Medicine and 1st Department of Infectious Diseases, General Hospital for Thoracic Diseases “Sotiria”, 115 27 Athens, Greece
12. Department of Internal Medicine, “Pammakaristos” Hospital, 111 44 Athens, Greece