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* |