Table 1 Differences in the characteristics between the Stable and Deteriorated groups in the original cohort of the study and external validation cohort

All

Stable group

Deteriorated group

All

Stable group

Deteriorated group

n = 1675

n = 1531

n = 144

n = 324

n = 283

n = 41

Age, year

41 (25–53)

39 (24–52)

51 (41.25–59.75)***

42 (29.3–52)

41 (27–51)

51 (39.5–60.5)^###

Male

919 (54.8%)

825 (53.9%)

94 (65.3%)***

181 (55.9%)

158 (55.8%)

23 (56.1%)^a

Mild / Moderate-1

947/728

900/631

47/97 ***

260/64

240/43

20/21 ^###

History of cigarette smoking

550 (38.0%)

479 (36.56%)

71 (52.59%)***

—

—

—

Temperature ≥ 37 °C

647 (40.4%)

549 (37.6%)

98 (68.5%)***

230 (71.0%)

195 (68.9%)

35 (85.4%)^#

Temperature ≥ 38 °C

291 (17.8%)

219 (14.7%)

72 (50.7%)***

96 (29.6%)

73 (25.8%)

23 (56.1%)^###

Diabetes or Obesity

175 (11.2%)

132 (9.26%)

43 (30.5%)***

53 (16.6%)

41 (14.7%)

12 (29.3%)^#

Hypertension

197 (12.6%)

155 (10.87%)

42 (29.8%)***

—

—

—

Chronic respiratory diseases

75 (4.8%)

67 (4.7%)

8 (5.7%)

—

—

—

Malignancies

37 (2.4%)

31 (2.2%)

6 (4.3%)

—

—

—

Dyslipidemia

80 (5.1%)

68 (4.74%)

12 (8.51%)

—

—

—

Cardiac diseases

40 (2.5%)

33 (2.30%)

7 (4.96%)

—

—

—

Pregnancy

13 (0.8%)

13 (0.8%)

0 (0%)

—

—

—

MV and/or ECMO

7 (0.4%)

0 (0%)

7 (0.4%)

—

—

—

Deceased due to COVID-19

1 (0.06%)

0 (0%)

1 (0.06%)

—

—

—

SpO₂, %

97 (97–98)

98 (97–98)

97 (96–97.75)***

97 (96–98)

97 (97–98)

97 (96–98)^b