Table 1.
Clinical characteristics between the two groups.
| Baseline Characteristics | Total (n = 81) |
Maximum FiO2 ≥ 0.4 | p-Value | |
|---|---|---|---|---|
| Yes (n = 16) | No (n = 65) | |||
| Mean age, y (±SD) | 62.0 ± 16.3 | 68.1 ± 13.9 | 60.6 ± 16.5 | 0.090 |
| Male sex, n (%) | 50 (61.7%) | 12 (75.0%) | 38 (58.5%) | 0.260 |
| Mean BMI, kg/m2 (±SD) | 25.0 ± 4.5 | 25.7 ± 4.4 | 24.9 ± 4.5 | 0.500 |
| Any comorbidities, n (%) | 52 (64.2%) | 15 (93.8%) | 37 (56.9%) | 0.007 |
| Hypertension, n (%) | 35 (43.2%) | 10 (62.5%) | 25 (38.5%) | 0.100 |
| Coronary artery disease, n (%) | 8 (9.9%) | 2 (12.5%) | 6 (9.2%) | 0.650 |
| Diabetes mellitus, n (%) | 18 (22.2%) | 5 (31.2%) | 13 (20.0%) | 0.330 |
| Chronic obstructive pulmonary disease, n (%) | 7 (8.6%) | 2 (12.5%) | 5 (7.7%) | 0.620 |
| Bronchial asthma, n (%) | 6 (7.4%) | 0 (0%) | 6 (9.2%) | 0.590 |
| Sleep apnea syndrome, n (%) | 8 (9.9%) | 2 (12.5%) | 6 (9.2%) | 0.650 |
| Chronic kidney disease, n (%) | 6 (7.4%) | 3 (18.8%) | 3 (4.6%) | 0.088 |
| Bacterial superinfection, n (%) | 2 (2.5%) | 1 (6.2%) | 1 (1.5%) | 0.360 |
| Laboratory parameters | ||||
| Median IL-6 level, pg/mL (IQR) | 24.5 (13.3–51.9) | 93.8 (52.4–121.5) | 18.0 (9.6–37.3) | <0.001 |
| Median CRP level, mg/dL (IQR) | 3.0 (1.1–7.9) | 8.7 (7.0–12.1) | 2.3 (0.9–5.7) | <0.001 |
| Median LDH level, IU/L (IQR) | 249 (203–329) | 335 (285–484) | 236 (193–300) | <0.001 |
| Median WBC count, ×103/mm3 (IQR) | 5.6 (4.2–7.8) | 8.3 (5.3–11.2) | 5.1 (3.9–7.3) | 0.003 |
| Median D-dimer level, μg/mL (IQR) | 0.7 (0.2–1.4) | 0.9 (0.8–2.0) | 0.5 (0.2–1.4) | 0.048 |
| Median Cr level, mg/dL (IQR) | 0.8 (0.7–1.1) | 1.1 (0.9–1.1) | 0.8 (0.7–1.1) | 0.027 |
| Treatments | ||||
| Invasive mechanical ventilation, n (%) | 14 (17.3%) | 13 (81.2%) | 1 (1.5%) | <0.001 |
| Supplemental oxygen, n (%) | 25 (30.9%) | 3 (18.8%) | 22 (33.8%) | 0.370 |
| Dexamethasone, n (%) | 63 (77.8%) | 16 (100%) | 47 (72.3%) | 0.017 |
| Favipiravir, n (%) | 53 (65.4%) | 9 (56.2%) | 44 (67.7%) | 0.400 |
| Median time from symptom onset to admission, days (IQR) | 4 (2–7) | 7 (5–7) | 4 (2–6) | 0.020 |
| Median time from symptom onset to the first measurement of blood samples, days (IQR) | 6 (4–9) | 7 (6–10) | 5 (3–9) | 0.030 |
| Prognosis | ||||
| Survivors, n (%) | 76 (93.8%) | 13 (81.2%) | 63 (96.9%) | 0.050 |
| Non-survivors, n (%) | 5 (6.2%) | 3 (18.8%) | 2 (3.1%) | |
FiO2, fraction of inspiratory oxygen; BMI, body mass index; SD, standard deviation; IQR, interquartile range; IL-6, interleukin-6; CRP, C-reactive protein; LDH, lactate dehydrogenase; WBC, white blood cell; Cr, creatinine.