Demographic and clinical characteristics of the analysed cohort
| Variable | Patients | P value | ||
| All (n=107) | Normal NfL (n=46) | Increased NfL (n=61) | ||
| Sex, female, n (%) | 25 (23.4) | 15 (32.6) | 10 (16.4) | 0.05 |
| Age (years), mean (SD) | 65.8 (11.9) | 65.2 (12.6) | 66.4 (11.6) | 0.60 |
| ICU stay, n (%) | 46 (43) | 10 (21.7) | 36 (59) | <0.001 |
| Illness onset (days), mean (SD) | 15.8 (7.9) | 11.3 (7.2) | 19.5 (6.4) | <0.001 |
| Comorbidity, n (%) | ||||
| Any | 91 (85) | 37 (80) | 54 (88.5) | 0.24 |
| Diabetes | 27 (25.2) | 11 (24) | 16 (26.2) | 0.78 |
| Hypertension | 74 (69.2) | 34 (73.9) | 40 (65.6) | 0.36 |
| Ischaemic cardiopathy | 25 (23.6) | 32 (23.9) | 50 (82) | 0.13 |
| Neoplasm | 13 (12.2) | 6 (13) | 7 (11.5) | 0.81 |
| Respiratory chronic diseases (COPD and asthma) | 12 (11.2) | 4 (8.7) | 8 (13.1) | 0.47 |
| BMI>30 | 12 (11.2) | 2 (4.3) | 10 (16.4) | 0.04 |
| Neurological symptoms, n (%)* | ||||
| Any | 59 (85.5) | 36 (94.7) | 23 (74.2) | 0.21 |
| Hyposmia | 15 (21.7) | 9 (23.7) | 6 (19.3) | 0.85 |
| Hypogeusia | 22 (31.9) | 14 (36.8) | 8 (25.8) | 0.51 |
| Vertigo | 6 (8.7) | 5 (13.2) | 1 (3.2) | 0.19 |
| Fatigue | 47 (68.1) | 25 (65.8) | 22 (71) | 0.24 |
| Headache | 12 (17.4) | 9 (23.7) | 3 (9.7) | 0.19 |
| Myalgia | 16 (23.2) | 11 (28.9) | 5 (16.1) | 0.32 |
| Altered consciousness | 13 (18.8) | 5 (13.1) | 8 (25.8) | 0.12 |
| Syncope | 6 (8.7) | 2 (5.3) | 4 (12.9) | 0.22 |
| Other symptoms/signs, n (%) | ||||
| Respiratory failure | 98 (91.6) | 38 (82.6) | 60 (98.4) | 0.003 |
| Diarrhoea | 25 (23.4) | 15 (32.6) | 10 (16.4) | 0.05 |
| Fever | 103 (96) | 43 (93.5) | 60 (98.4) | 0.19 |
| O2 support, n (%) | 82 (76.6) | 27 (58.7) | 55 (90.2) | <0.001 |
| Orotracheal intubation | 50 (46.7) | 9 (19.6) | 41 (67.2) | <0.001 |
*Questionnaire on neurological symptoms could not be administered in 38 patients.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; NfL, neurofilament light chain.