Table 2 Comparison of oxygenation indexes in surviving patients and non-surviving patients with acute respiratory distress syndrome (ARDS) in three cohorts

Data from the General Hospital of Tianjin Medical University

n = 258

n = 87

n = 250

n = 95

SpO₂/FiO₂ (median [IQR])

173.16 [145.13, 194.00]

144.26 [93.00, 172.73]

 < 0.001

174.55 [145.13, 194.00]

146.67 [93.50, 172.73]

 < 0.001

ROX

6.70 [4.82, 8.50]

5.00 [3.45, 7.25]

 < 0.001

6.70 [4.90, 8.50]

4.90 [3.45, 7.35]

 < 0.001

Berlin criteria ARDS

164 (63.6)

79 (90.8)

 < 0.001

156 (62.4)

87 (91.6)

 < 0.001

The severity of ARDS

 < 0.001

 < 0.001

 Mild

125 (48.4)

18 (20.7)

123 (49.2)

20 (21.1)

 Moderate

98 (38.0)

41 (47.1)

95 (38.0)

44 (46.3)

 Severe

35 (13.6)

28 (32.2)

32 (12.8)

31 (32.6)

APACHE II (median [IQR])

16.00 [13.00, 20.00]

23.00 [18.00, 28.00]

 < 0.001

18.00 [13.00, 22.00]

21.00 [16.00, 25.00]

0.001

SOFA (median [IQR])

6.00 [4.00, 9.00]

12.00 [8.00, 16.00]

 < 0.001

6.00 [4.00, 8.75]

12.00 [8.00, 16.00]

 < 0.001

Data from the EICU database

n = 2168

n = 516

n = 2149

n = 535

SpO₂/FiO₂ (median [IQR])

182.00 [140.00, 230.00]

153.33 [100.00, 190.00]

 < 0.001

182.00 [140.00, 230.00]

153.33 [100.00, 190.00]

 < 0.001

ROX

9.65 [7.10, 12.30]

8.00 [6.30, 11.00]

 < 0.001

9.70 [7.10, 12.30]

8.00 [6.30, 11.00]

 < 0.001

Berlin criteria ARDS

2131 (98.3)

507 (98.3)

1000

2112 (98.3)

526 (98.3)

1.000

The severity of ARDS (n (%))

 < 0.001

 < 0.001

 Mild

865 (39.9)

146 (28.3)

862 (40.1)

149 (27.9)

 Moderate

1075 (49.6)

247 (47.9)

1063 (49.5)

259 (48.4)

 Severe

228 (10.5)

123 (23.8)

224 (10.4)

127 (23.7)

SAPS II (median [IQR])

54.00 [33.00, 72.00]

48.00 [30.00, 73.00]

0.009

54.00 [33.00, 71.00]

49.00 [30.00, 73.00]

0.017

SOFA (median [IQR])

7.00 [5.00, 9.00]

11.00 [8.00, 14.00]

 < 0.001

7.00 [5.00, 9.00]

11.00 [8.00, 14.00]

 < 0.001

Data from the MIMIC IV database

n = 1648

n = 161

n = 1646

n = 163

SpO₂/FiO₂ (median [IQR])

168.00 [117.00, 222.50]

136.67 [97.00, 186.00]

 < 0.001

168.00 [117.00, 222.50]

136.00 [97.67, 183.00]

 < 0.001

ROX

6.45 [4.62, 8.54]

4.92 [3.18, 7.25]

 < 0.001

6.46 [4.63, 8.54]

4.88 [3.18, 7.10]

 < 0.001

Berlin criteria ARDS

1279 (77.6)

119 (73.9)

0.332

1278 (77.6)

120 (73.6)

0.284

The severity of ARDS (n (%))

 < 0.001

 < 0.001

 Mild

528 (32.0)

30 (18.6)

528 (32.1)

30 (18.4)

 Moderate

990 (60.1)

87 (54.0)

989 (60.1)

88 (54.0)

 Severe

130 (7.9)

44 (27.3)

129 (7.8)

5 (27.6)

SAPS II (median [IQR])

31.00 [25.00, 39.00]

47.00 [37.00, 60.00]

 < 0.001

31.00 [25.00, 39.00]

47.00 [37.00, 59.50]

 < 0.001

SOFA (median [IQR])

4.00 [3.00, 6.00]

8.00 [5.00, 12.00]

 < 0.001

4.00 [3.00, 6.00]

8.00 [5.00, 12.00]

 < 0.001