Table 1. Patient characteristics in the discovery and internal validation cohorts.

Characteristics	COVID-19 (n = 8)	Influenza (n = 8)	CAP (n = 34)	P value
Age (years)	25.1 (24.2 - 62.5)	29.5 (25.6 - 54.3)	31 (23.1 - 56.4)	0.93
Male, n(%)	4 (50%)	4 (50%)	22 (64.5%)	0.36
Fever, n (%)	2 (25%)	4 (50%)	15 (44.1%)	0.43
Cough, n (%)	2 (25%)	1 (12.5%)	12 (35.3%)	0.37
Sore throat, n (%)	2 (25%)	1 (12.5%)	3 (8.8%)	0.22
Fatigue, n (%)	2 (25%)	2 (25%)	4 (11.7%)	0.27
WBC (109/L)	5.3 (3.6 - 6)	4.9 (3.2 - 6.2)	5.5 (4.1 - 6.5)	0.65
Lymphocyte count (109/L)	0.93 (0.76 - 1.35)	1.4 (0.9 - 1.9)	1.5 (1.3 - 2.1)	0.08
Lymphocyte percentage (%)	14.2 ± 6.3	36.4 ± 7.1	33.9 ± 10.1	<0.001

The data are presented as the median and interquartile range (IQR), n (%) or mean and standard deviation (SD) For categorical data, chi-square test was used, and for continuous variables, Kruskal-Wallis was applied. WBC: white blood cell count.