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Table 1 Demographics among the derivation, internal-validation, and external-validation cohorts

From: Early prediction of noninvasive ventilation failure in COPD patients: derivation, internal validation, and external validation of a simple risk score

 

Derivation cohort

N = 500

Internal-validation cohort

N = 323

External-validation cohort

N = 395

p

Age, years

71.9 ± 10.1

72.2 ± 10.1

73.1 ± 9.7

0.16

Male

371 (74.2%)

255 (78.9%)

266 (67.3%)

< 0.01*

APACHE II score

17.1 ± 4.9

17.2 ± 5.0

13.5 ± 5.2

< 0.01*

Underlying disease

 Diabetes mellitus

92 (18.4%)

53 (16.4%)

26 (6.6%)

< 0.01*

 Hypertension

190 (38.0%)

126 (39.0%)

119 (30.1%)

0.02*

 Chronic heart disease

139 (27.8%)

84 (26.0%)

131 (33.2%)

0.08

 Chronic kidney disease

47 (9.4%)

22 (6.8%)

13 (3.4%)

< 0.01*

 Chronic liver disease

35 (7.0%)

31 (9.6%)

1 (0.3%)

< 0.01*

Data collected before NIV

 Respiratory rate, breaths/min

28 ± 6

29 ± 6

24 ± 4

< 0.01*

 Heart rate, beats/min

109 ± 21

110 ± 21

103 ± 22

< 0.01*

 Systolic blood pressure, mmHg

139 ± 27

141 ± 25

134 ± 24

< 0.01*

 Diastolic blood pressure, mmHg

81 ± 16

83 ± 17

77 ± 15

< 0.01*

 pH

7.26 ± 0.07

7.27 ± 0.06

7.25 ± 0.08

0.02*

 PaCO2, mmHg

82 ± 18

81 ± 17

79 ± 19

0.14

 PaO2/FiO2, mmHg

197 ± 94

208 ± 108

217 ± 112

0.02*

 GCS

14.4 ± 1.5

14.4 ± 1.5

14.0 ± 2.4

< 0.01*

Data collected at 1–2 h of NIV

 Respiratory rate, breaths/min

23 ± 5

24 ± 5

22 ± 4

< 0.01*

 Heart rate, beats/min

100 ± 21

100 ± 20

96 ± 21

0.01*

 Systolic blood pressure, mmHg

126 ± 23

128 ± 20

125 ± 20

0.26

 Diastolic blood pressure, mmHg

73 ± 14

74 ± 13

72 ± 12

0.47

 Minute ventilation, L/min

7.9 ± 3.2

8.0 ± 3.4

8.4 ± 2.9

0.03*

 IPAP, cmH2O

17 ± 4

17 ± 4

17 ± 4

0.44

 EPAP, cmH2O

6 ± 2

6 ± 2

5 ± 1

< 0.01*

 pH

7.33 ± 0.08

7.33 ± 0.08

7.31 ± 0.08

0.01*

 PaCO2, mmHg

72 ± 18

72 ± 18

72 ± 19

0.81

 PaO2/FiO2, mmHg

220 ± 89

222 ± 84

201 ± 81

< 0.01*

 GCS

14.5 ± 1.5

14.5 ± 1.4

14.2 ± 2.1

0.04*

Outcomes

 NIV failure

94 (18.8%)

61 (18.9%)

35 (8.9%)

< 0.01*

 Early NIV failure

64 (12.8%)

33 (10.2%)

18 (4.6%)

< 0.01*

 Late NIV failure

30 (6.0%)

28 (8.7%)

17 (4.3%)

0.05

 ICU mortality

57 (11.4%)

39 (12.1%)

15 (3.8%)

< 0.01*

 Hospital mortality

66 (13.2%)

47 (14.6%)

23 (5.8%)

< 0.01*

  1. GCS Glasgow coma scale, NIV noninvasive ventilation, IPAP inspiratory positive airway pressure, EPAP expiratory positive airway pressure, ICU intensive care unit
  2. *p < 0.05 between three groups