Baseline demographic and clinical characteristics
| Treated group n=86 | Control group n=86 | P value* | |
| Age (years) | 67 (12) | 67 (11) | 0.8250 |
| Male gender | 68/86 (79%) | 68/86 (79%) | |
| BMI (kg/m2) | 28.0 (4.9) | 29.7 (5.6) | 0.0418 |
| Number of days sick | 10.7 (5.5) | 9.3 (5.7) | 0.0948 |
| Smoking | |||
| Never smoker | 35/83 (42%) | 46/80 (58%) | 0.1460 |
| Ex-smoker | 40/83 (48%) | 28/80 (35%) | |
| Current smoker | 8/83 (10%) | 6/80 (8%) | |
| Positive COVID-19 PCR | 76/85 (89%) | 84/86 (98%) | 0.0280 |
| CO-RADS | 4.7 (0.4) | 4.8 (0.4) | 0.7752 |
| 4 | 22/85 (26%) | 15/63 (24%) | 0.7730 |
| 5 | 63/85 (74%) | 48/63 (76%) | |
| Hypertension | 19/86 (22%) | 27/86 (31%) | 0.1680 |
| Diabetes | 9/86 (11%) | 23/86 (27%) | 0.0060 |
| COPD | 10/86 (12%) | 7/86 (8%) | 0.4430 |
| Asthma | 7/86 (8%) | 5/86 (6%) | 0.5490 |
| Malignancy | 4/86 (5%) | 5/86 (6%) | 0.7320 |
| Cardiovascular disease | 17/86 (20%) | 11/86 (13%) | 0.2150 |
| Heart failure | 2 (2%) | 3/86 (3%) | 0.6500 |
| Arrhythmia | 14/86 (16%) | 5/86 (6%) | 0.0290 |
| Chronic kidney disease | 4/86 (5%) | 7/86 (8%) | 0.3500 |
| Cerebrovascular disease | 4/86 (5%) | 6/86 (7%) | 0.5150 |
| Peripheral vascular disease | 5/86 (6%) | 5/86 (6%) | 1.0000 |
| Autoimmune disease | 9/86 (10%) | 12/86 (14%) | 0.4850 |
| Peptic ulcer | 1/86 (1%) | 0/86 (0%) | 0.3160 |
| Moderate or severe liver disease | 0/86 (0%) | 1/86 (1%) | 0.3160 |
| Charlson Comorbidity Index (0–34) | 0.90 (1.14) | 1.16 (1.39) | 0.1688 |
| WHO score | 4.3 (0.5) | 4.4 (0.7) | 0.1761 |
| 4: hospitalisation, requiring oxygen | 65/86 (76%) | 66/86 (77%) | <0.0001 |
| 5: hospitalisation requiring high-flow nasal oxygen therapy or non-invasive ventilation | 20/86 (23%) | 7/86 (8%) | |
| 6: hospitalisation requiring ECMO, invasive mechanical ventilation or both | 1/86 (1%) | 13/86 (15%) | |
| Oxygen support at baseline | |||
| Nasal oxygen | 41/86 (48%) | 41/86 (48%) | 0.0010 |
| OxyMask/NRM | 24/86 (28%) | 25/86 (29%) | |
| High-flow oxygen | 20/86 (23%) | 7/86 (8%) | |
| Mechanical ventilation | 1/86 (1%) | 13/86 (15%) | |
| Oxygen saturation | 92 (10) | 92 (6) | 0.7432 |
| CRP (mg/L) | 160 (73) | 167 (98) | 0.5497 |
| Ferritin (μg/L) | 1493 (926) | 1849 (1281) | 0.0562 |
| D-dimers (μg/L) | 3935 (7350) | 5633 (9408) | 0.3470 |
Data are mean (SD) or n/N (%).
*Calculated with t-test or χ2, as appropriate.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; CO-RADS, COVID-19 CT Classification; CRP, C-reactive protein; ECMO, extracorporeal membrane oxygenation; NRM, non-rebreathing mask.