Table 1.
Distribution of covariates of interest in the unadjusted and weighted populations
| Early intubation | Yes | No | P value | SMD | Yes | No | P value | SMD |
|---|---|---|---|---|---|---|---|---|
| Number of subjects | 137 | 598 | 78 | 78 | ||||
| Age | 66 (15) | 65 (14) | 0.442 | 0.074 | 67 (14) | 67 (13) | 0.844 | 0.032 |
| Body mass index | 28 (6) | 27 (7) | 0.070 | 0.164 | 28 (6) | 27 (7) | 0.536 | 0.099 |
| Neurological criteria for intubation, n (%) | 37 (27) | 6 (1) | < 0.001 | 0.26 | 3 (4) | 4 (5) | 1.000 | 0.062 |
| Number of respiratory criteria for intubation | < 0.001 | 0.467 | 0.199 | |||||
| 0–1 | 37 (27) | 481 (80) | 0.534 | 28 (36) | 34 (44) | |||
| 2–3 | 66 (48) | 107 (18) | 0.303 | 39 (50.0) | 37 (47) | |||
| 4–6 | 34 (25) | 10 (2) | 0.231 | 11 (14) | 7 (9.0) | |||
| Pulmonary sepsis, n (%) | 48 (35) | 137.0 (23) | 0.003 | 0.121 | 30 (39) | 24 (31) | 0.400 | 0.162 |
| Respiratory rate (rpm) | 31 (8) | 26 (7) | < 0.001 | 0.618 | 30 (7) | 30 (7) | 0.837 | 0.033 |
| PaO2/FiO2 | 138 [85, 232] | 275 [192, 381] | < 0.001 | 0.884 | 141 [89, 230] | 153 [102, 232] | 0.423 | 0.020 |
| PaCO2 (mmHg) | 37 (15) | 32 (8) | 0.001 | 0.388 | 34 (10) | 33 (11) | 0.765 | 0.048 |
| Accessory muscle use, n (%) | 89.0 (65.0) | 70.0 (11.7) | < 0.001 | 0.533 | 43 (0.55) | 36 (0.46) | 0.337 | 0.179 |
| Inability to clear secretions, n (%) | 41.0 (29.9) | 52.0 (8.7) | < 0.001 | 0.212 | 18 (0.23) | 17 (0.22) | 1.000 | 0.031 |
| pH | 7.25 (0.15) | 7.37 (0.08) | < 0.001 | 1.005 | 7.31 (0.10) | 7.31 (0.09) | 0.967 | 0.007 |
| Lactate (mmol/L) | 4.3 [2.6, 6.6] | 2.2 [1.6, 3.3] | < 0.001 | 0.811 | 3.5 [2, 4.5] | 3 [2, 5.5] | 0.487 | 0.071 |
| Non-respiratory SOFA | 9 [7–12] | 8 [6–9] | < 0.001 | 0.706 | 8 [7, 10] | 8 [7, 11] | 0.970 | 0.032 |
| Norepinephrine dose (mcg/kg/min) | 0.59 [0.33, 1.00] | 0.26 [0.15, 0.47] | < 0.001 | 0.790 | 0.50 [0.28, 0.77] | 0.51 [0.26, 0.88] | 0.762 | 0.120 |
| Glasgow Coma Scale | 14 [9, 15] | 15 [15] | < 0.001 | 0.949 | 15 [14, 15] | 15 [14, 15] | 0.785 | 0.020 |
| Platelet count, (1012/L) | 170 (130) | 170 (110) | 0.953 | 0.006 | 160 (119) | 151 (105) | 0.614 | 0.081 |
| Bilirubin, (mmol/L) | 16 [9, 36] | 15 [10, 27] | 0.326 | 0.197 | 16 [9, 27] | 15 [10, 25] | 0.869 | 0.171 |
| Creatinine, (mmol/L) | 220 (172) | 172 (153) | 0.003 | 0.294 | 206 (161) | 212 (184) | 0.813 | 0.038 |
| Renal replacement at T8 | 11 (8) | 26 (4) | 0.076 | 0.04 | 4 (5) | 3 (4) | 1.000 | 0.062 |
| Median days of MV by center | 6 [3, 7] | 6 [3, 7] | 0.666 | 0.004 | 5 [3, 7] | 6 [3, 6] | 0.727 | 0.139 |
| Intubation rate by center (%) | 0.22 [0.17, 0.33] | 0.22 [0.17, 0.33] | 0.514 | 0.038 | 0.21 [0.17, 0.32] | 0.23 [0.17, 0.33] | 0.600 | 0.072 |
| Mortality rate by center (%) | 0.23 [0.20, 0.29] | 0.23 [0.20, 0.29] | 0.726 | 0.039 | 0.23 [0.20, 0.29] | 0.23 [0.20, 0.29] | 0.801 | 0.007 |