Table 1.
Comparison of baseline characteristics of unmatched and matched patients according to the survival status
| Variables | Original cohort | Matched cohort | ||||
|---|---|---|---|---|---|---|
| Survivors (n=183) | Non-survivors (n=85) | P value | Survivors (n=56) | Non-survivors (n=56) | P value | |
| Age (years) | 67 (59–72) | 67 (63–73) | 0.165 | 67 (60.25–73) | 67 (62–73) | 0.730 |
| Male, n (%) | 133 (72.7) | 59 (69.4) | 0.581 | 39 (69.6) | 39 (69.6) | 1.000 |
| Smoking, n (%) | 60 (32.8) | 25 (29.4) | 0.581 | 14 (25) | 18 (32.1) | 0.557 |
| Alcohol abuse, n (%) | 45 (24.6) | 18 (21.2) | 0.540 | 10 (17.9) | 12 (21.4) | 0.815 |
| Hypertension, n (%) | 85 (46.4) | 31 (36.5) | 0.125 | 22 (39.3) | 24 (42.9) | 0.851 |
| Diabetes mellitus, n (%) | 52 (28.4) | 22 (25.9) | 0.666 | 21 (37.5) | 17 (30.4) | 0.572 |
| Coronary artery disease, n (%) | 36 (19.7) | 18 (21.2) | 0.775 | 12 (21.4) | 13 (23.2) | 1.000 |
| Risk factor, n (%) | 0.531 | 0.912 | ||||
| Pneumonia | 167 (91.3) | 79 (92.9) | 51 (91.1) | 51 (91.1) | ||
| Aspiration | 8 (4.4) | 2 (2.4) | 2 (3.6) | 1 (1.7) | ||
| Sepsis | 3 (1.6) | 3 (3.5) | 2 (3.6) | 3 (5.5) | ||
| Others | 5 (2.7) | 1 (1.2) | 1 (1.7) | 1 (1.7) | ||
| Types of infection, n (%) | 0.941 | 0.931 | ||||
| Bacteria | 139 (76%) | 64 (75.3%) | 49 (87.6) | 49 (87.6) | ||
| Virus | 6 (3.3%) | 2 (2.4%) | 1 (1.7) | 1 (1.7) | ||
| Fungus | 24 (13.1) | 13 (15.3%) | 1 (1.7) | 2 (3.6) | ||
| Unknown | 14 (7.6%) | 6 (7 %) | 5 (9) | 4 (7.1) | ||
| PaO2/FiO2 (mmHg) | 145 (106–208.18) | 131 (85.6–177.03) | 0.032 | 144.64±62.79 | 145.40 ±58.73 | 0.948 |
| Categories of ARDS, n (%) | 0.015 | 0.770 | ||||
| Mild | 47 (25.7) | 10 (11.8) | 12 (21.4) | 9 (16.1) | ||
| Moderate | 95 (51.9) | 46 (54.1) | 27 (48.2) | 32 (57.1) | ||
| Severe | 41 (22.4) | 29 (34.1) | 17 (30.4) | 15 (26.8) | ||
| WBC, 109/L | 9.8 (7.02–11.84) | 9.22 (6–11.46) | 0.249 | 10.44 (8.55–12.15) | 9.62 (7.73–11.44) | 0.153 |
| Hemoglobin, g/L | 111 (96–127) | 111 (94.5–126) | 0.460 | 106 (94–126.75) | 112 (99–126.75) | 0.884 |
| RDW, % | 14 (13–15.3) | 13.6 (12.85–14.6) | 0.175 | 13.9 (12.75–15.28) | 13.45 (12.8–14.55) | 0.964 |
| Lactate, mmol/L | 2.2 (1.4–3.7) | 2.6 (1.55–4.3) | 0.082 | 2.1 (1.3–3.33) | 2.6 (1.5–3.73) | 0.152 |
| Albumin, g/L | 32.9 (28.9–37.7) | 32.30 (28.6–37.5) | 0.417 | 32.89±6.98 | 32.86±5.86 | 0.979 |
| MLR | 0.49 (0.27–0.8) | 1 (0.5–1.74) | <0.001 | 0.56 (0.34–0.77) | 0.83(0.47–1.68) | 0.001 |
| NLR | 10.61(4.75–19.42) | 14.28 (7.97–23.62) | 0.003 | 13.56 (5.98–25.12) | 12.96 (7.18–20.75) | 0.613 |
| RDW/albumin, %/g/L | 0.43 (0.37–0.51) | 0.43 (0.37–0.5) | 0.914 | 0.43 (0.36–0.52) | 0.43 (0.36–0.49) | 0.660 |
| AST | 52.2 (20.5–145.2) | 71 (28.7–138.3) | 0.317 | 42.35 (20.1–128.25) | 88.05 (36.98–147.9) | 0.011 |
| ALT | 62 (20–126) | 40.3 (21.1–133.3) | 0.485 | 44.6 (16.13–103.75) | 43.4 (23.03–139.15) | 0.324 |
| Cr, μmol/L | 100.7 (60.2–183) | 124.9 (62–198.15) | 0.357 | 107 (58.18–188.7) | 111.3(60.65-192) | 0.695 |
| BUN, mmol/L | 13.31 (7–18) | 13.55 (9.85–19.25) | 0.232 | 13.09±6.45 | 13.89±7.28 | 0.512 |
| APACHE II score | 12 (9–16) | 15 (10–18) | 0.004 | 14.09±4.50 | 13.66 ±4.57 | 0.628 |
| SOFA score | 7 (6–9) | 8 (7–9) | 0.009 | 8 (7–9) | 8 (6.25–9) | 0.340 |
| Interventions, n (%) | ||||||
| Steroida | 121 (66.1) | 63 (74.1) | 0.189 | 39 (69.6) | 42 (75) | 0.690 |
| Hypoglycemic | 56 (30.6) | 25 (29.4) | 0.844 | 25 (44.6) | 19 (33.9) | 0.362 |
| Alimentotherapy | 113 (61.7) | 66 (77.6) | 0.010 | 39 (69.6) | 42 (75) | 0.607 |
| Albumin infusion | 81 (44.3) | 56 (66.9) | 0.001 | 36 (64.3) | 30 (53.6) | 0.286 |
| Transfusion | 50 (27.3) | 33 (38.8%) | 0.037 | 19 (33.9) | 19(33.9) | 1.000 |
| CRRT | 22 (12) | 17 (20) | 0.085 | 8 (14.3) | 8 (14.3) | 1.000 |
| ECMO | 6 (3.3) | 5 (5.8) | 0.317 | 1 (1.7) | 1 (1.7) | 1.000 |
| Mechanical ventilation | 108 (59) | 51 (60) | 0.879 | 37 (66.1) | 35 (62.5) | 0.851 |
| Duration of ventilation | 7 (2–13) | 8 (3.5–13) | 0.479 | 8.95±7.03 | 9.05±6.43 | 0.933 |
| Hospital length of stay | 20 (12–26) | 17 (11–23) | 0.038 | 19.00±9.81 | 18.30±8.19 | 0.662 |
aSteroid therapy was defined as at least a dose (≥ 0.5mg/kg) of methylprednisolone during hospitalization
ARDS, acute respiratory distress syndrome; WBC, white blood cell; RDW, red cell distribution width; MLR, monocyte-to-lymphocyte ratio; NLR, neutrophil-to-lymphocyte ratio; AST, aspartate aminotransferase; ALT, alanine aminotransferase; Cr, creatinine; BUN, blood urea nitrogen; APACHE II, Acute Physiology and Chronic Health Evaluation II; SOFA, Sequential Organ Failure Assessment; CRRT, continuous renal replacement therapy; ECMO, extracorporeal membrane oxygenation