Table I.

Baseline demographic and clinical characteristics

Characteristic	Control group (n = 65)	Early AIT group (n = 63)	SMD	P value
Age (y), mean (SD) Median, range	67.3 (16.0) 68 (27-89)	60.7 (15.7) 59 (23-88)	0.42	.020
Sex (M/F), no. (%)	45/20 (69.2/30.8)	42/21 (66.7-33.3)	0.055	.85
Comorbidities (no.), mean (SD) Median (range)	1.5 (1.5) 1 (0-5)	1.0 (1.1) 1 (0-4)	0.34	.13
Time of first symptom/admission (d), median (IQR)	5 (2-7)	7 (4-9)	0.30	.004
Ferritin level (ng/mL), mean (SD) Median (IQR)	645 (707) 470 (202-810)	1174 (810) 951 (595-1543)	0.70	<.001
CRP level (mg/dL), mean (SD) Median (IQR)	7.5 (7.5) 4.1 (1.9-11.0)	9.8 (6.3) 8.7 (4.4-13.5)	0.33	.007
d-Dimer level (ng/mL), mean (SD) Median (IQR)	1870 (2215) 1142 (785-2267)	2226 (5499) 813 (535-1570)	0.085	.15
LDH level (U/L), mean (SD) Median (IQR)	306 (146) 278 (198-398)	378 (137) 349 (272-453)	0.51	.002
Lymphocyte count (per mm3), mean (SD) Median (IQR)	1.33 (1.34) 1.05 (0.8-1.35)	0.98 (0.50) 0.85 (0.67-1.28)	0.34	.055
Pao2/Fio2 ratio (mm Hg), median (IQR)	301 (217-374)	223 (147-300)	0.69	<.001
Pao2/Fio2 ratio < 300 mm Hg, no. (%)	33 (50)	48 (76.2)	0.56	.006
Diabetes, no. (%)	17 (26.2)	11 (17.5)	0.21	.29
Hypertension, no. (%)	27 (41.5)	22 (34.9)	0.14	.47
Cardiovascular disease, no. (%)	19 (29.2)	8 (12.7)	0.41	.03
COPD, no. (%)	10 (15.4)	5 (7.9)	0.23	.27
Malignancy, no. (%)	9 (13.9)	13 (20.6)	0.18	.35
Smoker, no. (%)	8 (12.3)	5 (7.9)	0.14	.56
Anticoagulant therapy, no. (%)	50 (76.9)	60 (95.2)	0.54	.004
Antiviral therapy, no. (%)	42 (64.6)	24 (38.1)	0.55	.004
Treated with CPAP at admission, no. (%)	9 (13.9)	22 (34.9)	0.50	.007
Mechanical ventilation at admission, no. (%)	5 (7.7)	7 (11.1)	0.12	.56

COPD, Chronic obstructive pulmonary disease; CPAP, continuous positive airway pressure; IQR, interquartile range.