Table 1.
Baseline and clinical characteristics of the study population
| Characteristics | All (n = 494) | Survivors (n = 417) | Non-survivors (n = 77) | P value |
|---|---|---|---|---|
| Age, years (mean ± SD) | 70.8 ± 10.4 | 69.9 ± 10.5 | 75.3 ± 8.6 | < 0.001a |
| Gender, n (%) | ||||
| Male | 248 (50.2) | 210 (50.4) | 38 (49.4) | 0.871b |
| Female | 246 (49.8) | 207 (49.6) | 39 (50.6) | 0.871b |
| Laboratory test, median (IQR) | ||||
| WBC count (103/μL) | 11.1 (8.0, 15.6) | 10.9 (8.0, 15.1) | 12.0 (9.1, 17.7) | 0.084c |
| Neutrophil count (103/μL) | 9.2 (6.2, 13.2) | 8.8 (6.1, 13.0) | 10.4 (7.2, 15.1) | 0.019c |
| Lymphocyte count (103/μL) | 0.9 (0.5, 1.6) | 0.9 (0.5, 1.6) | 0.8 (0.4, 1.2) | 0.015c |
| Platelet count (103/μL) | 236 (175, 308) | 239 (175, 307) | 224 (162, 309) | 0.434c |
| Hemoglobin (g/dL) | 10.8 (9.6, 12.3) | 10.9 (9.6, 12.4) | 10.6 (9.5, 11.5) | 0.145c |
| Serum albumin (g/dL) | 3.2 (2.7, 3.6) | 3.3 (2.8, 3.7) | 2.9 (2.6, 3.4) | < 0.001c |
| Serum sodium (mmol/L) | 138 (134, 141) | 137 (134, 141) | 137 (134, 140) | 0.592c |
| Serum potassium (mmol/L) | 4.2 (3.7, 4.7) | 4.2 (3.7, 4.7) | 4.1 (3.5, 4.6) | 0.080c |
| Serum calcium (mmol/L) | 1.13 (1.07, 1.19) | 1.13 (1.10, 1.19) | 1.13 (1.10, 1.16) | 0.982c |
| pH | 7.34 (7.25, 7.40) | 7.34 (7.26, 7.40) | 7.32 (7.25, 7.40) | 0.503c |
| pO2 (mmHg) | 103 (74, 187) | 107 (76, 192) | 88 (61, 167) | 0.018c |
| pCO2 (mmHg) | 67 (53, 72) | 53 (44, 72) | 52 (46, 71) | 0.810c |
| Bicarbonate (mmol/L) | 28 (25, 33) | 28 (25, 33) | 30 (25,34) | 0.574c |
| ALT (IU/L) | 23 (15, 40) | 23 (15, 40) | 21 (15, 40) | 0.975c |
| AST (IU/L) | 27 (18, 42) | 26 (18, 42) | 27 (17, 46) | 0.968c |
| Serum creatinine (mg/dL) | 1.0 (0.7, 1.4) | 1.0 (0.7, 1.4) | 1.0 (0.7, 1.3) | 0.787c |
| BUN (mmol/L) | 25 (18, 38) | 24 (18, 36) | 28 (21, 44) | 0.021c |
| Mean vital signs, median (IQR) | ||||
| Temperature (℃) | 36.7 (36.4, 37.1) | 36.7 (36.3, 37.1) | 36.7 (36.4, 37.1) | 0.738c |
| MAP (mmHg) | 77 (71, 85) | 77 (71, 84) | 75 (70, 83) | 0.176c |
| Heart rate (min−1) | 90 (80, 100) | 89 (80, 99) | 90 (81, 103) | 0.142c |
| Respiratory rate (min−1) | 20 (17, 23) | 20 (17, 23) | 20 (17, 23) | 0.587c |
| Comorbidities, n (%) | ||||
| Hypertension | 246 (49.8) | 216 (51.8) | 30 (39.0) | 0.038b |
| DM | 137 (27.7) | 124 (29.7) | 13 (16.9) | 0.021b |
| CHD | 112 (22.7) | 94 (22.5) | 18 (23.4) | 0.352b |
| CKD | 83 (16.8) | 75 (18.0) | 8 (10.4) | 0.101b |
| Maligancy | 131 (26.5) | 108 (25.9) | 23 (29.9) | 0.468b |
| Inflammatory indicators, median (IQR) | ||||
| NLR | 8.8 (5.0, 16.6) | 8.8 (5.0, 16.6) | 14.6 (6.6, 31.5) | < 0.001c |
| PLR | 246.3 (133.9, 467.7) | 237.5 (129.5, 436.9) | 295.9 (175.6,593.2) | 0.022c |
| PNI | 33.3 (28.6, 37.6) | 33.8 (29.2, 38.0) | 30.1 (26.2, 35.4) | < 0.001c |
| Scoring system, median (IQR) | ||||
| SAPSII | 39 (32, 47) | 38 (31, 45) | 44 (38, 51) | < 0.001c |
| SOFA | 4 (2, 6) | 4 (2, 6) | 5 (4, 7) | 0.007c |
| Treatment, n (%) | ||||
| IMV | 240 (48.6) | 193 (46.3) | 47 (61.0) | 0.002b |
| Vasopressor | 177 (35.8) | 135 (32.4) | 42 (54.5) | < 0.001b |
Normally distributed data are presented as the mean ± SD, non-normally distributed data are presented as median (IQR) and categorical variables are presented as n (%)
aThe analysis was performed by using independent samples Student's T test
bThe analysis was performed by using χ2-test
cThe analysis was performed by using Mann–Whitney U-test
ALT alanine transaminase, AST aspartate transaminase, BUN blood urea nitrogen, CHD coronary heart disease, CKD chronic kidney disease, DM diabetes mellitus, IMV invasive mechanical ventilation, MAP mean atrial pressure, NLR neutrophil-to-lymphocyte ratio, PLR platelet-to-lymphocyte ratio, PNI prognostic nutritional index, SAPSII simplified acute physiology score II, SOFA sequential organ failure assessment, WBC white blood cell