Table 2 Multivariate analysis for severe adverse events in the derivation cohort

Intercept

− 3.82

Chronic lung diseases

No

166

717

0

1 (Ref)

Yes

111

340

0.31

1.36 (0.97–1.93)

1

Altered mental status

No

158

910

0

1 (Ref)

Yes

119

147

0.76

2.14 (1.48–3.08)

2

Systolic blood pressure, mmHg

 ≥ 90

247

1013

0

1 (Ref)

 < 90

30

44

0.61

1.85 (1.02–3.35)

2

Respiratory rate, /min

 < 30

169

854

0

1 (Ref)

 ≥ 30

108

203

0.30

1.35 (0.95–1.92)

1

Albumin, g/dL

 ≥ 3.0

134

749

0

1 (Ref)

2.0–3.0

128

288

0.44

1.55 (1.11–2.19)

1

 < 2.0

15

20

0.74

2.09 (0.90–4.86)

2

Potassium, mEq/L

 < 5.0

226

986

0

1 (Ref)

 ≥ 5.0

51

71

0.80

2.22 (1.39–3.56)

2

White blood cell count, cells/μL

 ≥ 4000

254

1036

0

1 (Ref)

 < 4000

23

21

1.24

3.45 (1.68–7.11)

3

PaO₂/F_IO₂ ratio, mmHg

 > 300

47

485

0

1 (Ref)

200–300

85

397

0.52

1.68 (1.10–2.55)

1

100–200

82

127

1.02

2.76 (1.71–4.45)

3

 ≤ 100

63

48

1.40

4.07 (2.28–7.26)

3

Arterial pH

 ≥ 7.35

193

993

0

1 (Ref)

 < 7.35

84

64

0.82

2.27 (1.41–3.66)

2

PaCO₂, mmHg

 ≤ 45

182

940

0

1 (Ref)

 > 45

95

117

0.91

2.47 (1.60–3.82)

2

HCO₃⁻, mmol/L

 ≥ 20

218

946

0

1 (Ref)

 < 20

59

111

0.59

1.80 (1.14–2.83)

1

Pleural effusion

No

178

832

0

1 (Ref)

Yes

99

225

0.52

1.68 (1.18–2.39)

1

Extent of total infiltration

 < 1/3 of unilateral lung

71

580

0

1 (Ref)

1/3–2/3 of unilateral lung

100

315

0.48

1.62 (1.09–2.39)

1

 > 2/3 of unilateral lung

106

162

0.74

2.10 (1.36–3.24)

2