Table 1.
Summary statistics of patient demographics and clinical characteristics (by quartile of LOS).
| Total | ≤10 days (n = 26) | 11–18 days (n = 49) | ≥19 days (n = 22) | p value | |
|---|---|---|---|---|---|
| Demographic characteristics | |||||
| Age, years (IQR) | 51.5 (38–64) | 41.0 (31,62.5) | 49 (37–60) | 63 (57–74.8) | ≤0.001∗∗∗ |
| Male sex, n (%) | 41 (42.3) | 9 (34.6) | 18 (36.7) | 14 (63.6) | 0.069 |
| Clinical findings | |||||
| Pneumonia, n (%) | |||||
| Mild | 69 (71.1) | 23 (88.5) | 39 (79.6) | 7 (31.8) | ≤0.001∗∗∗ |
| Severe | 17 (17.5) | 3 (11.5) | 8 (16.3) | 6 (27.3) | |
| Critical | 11 (11.3) | 0 (0.0) | 2 (4.1) | 9 (40.9) | |
| Fever (°C), n (%) | |||||
| <37.3 | 24 (24.7) | 11 (42.3) | 11 (22.4) | 2 (9.1) | 0.045∗ |
| 37.3–38.5 | 50 (51.5) | 13 (50.0) | 24 (49.0) | 13 (59.1) | |
| >38.5 | 23 (23.7) | 2 (7.7) | 14 (28.6) | 7 (31.8) | |
| Cough | 58 (59.8%) | 13 (46.4%) | 31 (62%) | 15 (68.2%) | 0.423 |
| Sputum | 25 (25.8%) | 5 (19.2%) | 12 (24.5%) | 8 (36.4%) | 0.384 |
| Vomiting | 4 (4.1%) | 1 (3.8%) | 2 (4.1%) | 1 (4.5%) | 0.993 |
| Diarrhea | 2 (2.1%) | 1 (3.8%) | 0 (0%) | 1 (4.5%) | 0.238 |
| Lung CT(a) | 85 (87.6%) | 21 (80.8%) | 44 (91.8%) | 19 (86.4%) | 0.384 |
| Coexisting illnesses | |||||
| Kidney disease | 3 (3.1%) | 1 (3.80%) | 2 (4.1%) | 0 (0.0%) | 0.455 |
| Hypertension | 22 (22.7%) | 2 (15.4%) | 9 (18.4%) | 9 (40.9%) | 0.081 |
| Hyperlipidemia | 3 (3.1%) | 1 (3.8%) | 1 (2.0%) | 1 (4.5%) | 0.825 |
| Diabetes | 8 (8.2%) | 2 (7.7%) | 4 (8.2%) | 3 (13.6%) | 0.984 |
| Heart disease | 10 (10.3%) | 2 (7.7%) | 5 (10.2%) | 2 (10.5%) | 0.798 |
| Lung disease | 7 (7.2%) | 2 (7.7%) | 4 (8.2%) | 1 (4.5%) | 0.844 |
| Surgery | 22 (22.7%) | 4 (15.4%) | 12 (24.5%) | 6 (27.3%) | 0.564 |
| Laboratory indicators | |||||
| White blood cell count, ×109/L | 4.4 (3.5–5.9) | 4.1 (3.5–5.8) | 4.4 (3.5–5.7) | 5.0 (3.2–6.9) | 0.583 |
| <4 | 40 (41.2%) | 12 (46.2%) | 20 (40.8%) | 8 (36.4%) | 0.787 |
| ≥4 | 57 (58.8%) | 14 (53.8%) | 29 (59.2%) | 14 (63.6%) | |
| Hemoglobin, g/dL | 136 (125–144) | 131 (120.3–144.3) | 135 (126–143.5) | 139 (129–149) | 0.157 |
| Platelet count × 109/L | 194 (160–238) | 206 (161–298.3) | 193 (144.5–245) | 191 (147.5–226.3) | 0.257 |
| <100 | 5 (5.2%) | 0 (0.0%) | 2 (4.1%) | 5 (10.2%) | 0.071 |
| 100–300 | 80 (82.5%) | 20 (76.9%) | 42 (85.7%) | 6 (23.1%) | |
| >300 | 12 (12.4%) | 6 (23.1%) | 5 (10.2%) | 1 (4.5%) | |
| Lymphocyte count × 109/L | 1.1 (0.77–1.53) | 1.26 (0.93–1.61) | 1.18 (0.80–1.54) | 0.81 (0.70–1.21) | 0.026∗ |
| <0.8 | 26 (26.8%) | 5 (19.2%) | 11 (22.4%) | 10 (45.5%) | 0.90 |
| ≥0.8 | 71 (73.2%) | 21 (80.8%) | 38 (77.6%) | 12 (54.5%) | |
| Monocyte count×109/L | 0.31 (0.21–0.44) | 0.34 (0.22–0.42) | 0.25 (0.16–0.39) | 0.32 (0.19–0.51) | 0.928 |
| Neutrophil count × 109/L | 2.69 (1.84–4.09) | 2.37 (1.86–3.42) | 2.69 (1.84–3.83) | 3.71 (1.68–5.38) | 0.067 |
| <1.8 | 21 (21.6%) | 5 (19.2%) | 10 (20.4%) | 6 (27.3%) | 0.206 |
| 1.8–6.3 | 70 (72.2%) | 21 (80.8%) | 36 (73.5%) | 13 (59.1%) | |
| >6.3 | 6 (6.2%) | 0 (0%) | 3 (6.1%) | 3 (13.6%) | |
| Lymphocyte percentage | 26.1 (17.9–34.5) | 33 (21.7–37.8) | 26.1 (19.3–34.3) | 18.7 (19.3–34.5) | 0.002∗∗ |
| <20 | 29 (29.9%) | 3 (11.5%) | 14 (28.6%) | 12 (54.5%) | 0.007∗∗ |
| 20–40 | 58 (59.8%) | 19 (73.1%) | 29 (59.2%) | 10 (45.5%) | |
| >40 | 10 (10.3%) | 4 (15.4%) | 6 (12.2%) | 0 (0.0%) | |
| Neutrophil percentage | 64.0 (51.8–72.3) | 55.4 (49.2–69.1) | 64 (53.1–72.7) | 70.4 (60.4–79.6) | 0.002∗∗ |
| <75 | 78 (80.4%) | 25 (96.2%) | 39 (79.6%) | 14 (63.6%) | 0.018∗ |
| ≥75 | 19 (19.6%) | 1 (3.8%) | 10 (20.4%) | 8 (36.4%) | |
| NLR | 2.4 (1.4, 3.9) | 1.7 (1.3–3.1) | 2.3 (1.6–3.8) | 3.61 (1.8–6.3) | 0.004∗∗ |
| <2.75 | 56 (57.7%) | 18 (69.2%) | 31 (63.3%) | 7 (31.8%) | 0.018∗ |
| 2.75 | 41 (42.3%) | 8 (30.8%) | 18 (36.7%) | 15 (68.2%) | |
| LMR | 3.7 (2.8, 5.3) | 4.1 (2.9, 6.3) | 3.9 (2.8, 5.4) | 3.0 (2.3,4.8) | 0.268 |
| <2.63 | 20 (20.8%) | 5 (19.2%) | 7 (14.3%) | 8 (38.1%) | 0.096 |
| ≥2.63 | 76 (79.2%) | 21 (80.8%) | 42 (85.7%) | 8 (61.9%) | |
| PLR | 177.3 (124.8–246.2) | 132.7 (118.5–172.3) | 188.1 (124.8–156.6) | 221.5 (163.6–182.5) | 0.018∗ |
| <160 | 41 (42.3%) | 15 (57.7%) | 21 (42.9%) | 5 (22.7%) | 0.045 |
| ≥160 | 56 (57.7%) | 11 (42.3%) | 28 (57.1%) | 17 (77.3%) | |
| Prothrombin time, s | 12.6 (12.1–131.1) | 12.8 (12.2–13.4) | 12.4 (11.9–12.87) | 12.75 (12.1–13.42) | 0.417 |
| Prothrombin activity, percentage | 75 (71–80) | 73.5 (68.5–79.0) | 76.0 (73.0–82.0) | 74.0 (68.5–78.5) | 0.459 |
| <75 | 46 (48.4%) | 15 (57.7%) | 19 (39.6%) | 12 (57.1%) | 0.219 |
| ≥75 | 49 (51.6%) | 11 (43.3%) | 29 (60.4%) | 9 (42.9%) | |
| C-reactive protein, mg/L | 14.7 (3.4–37.4) | 12.7 (2.0–18.3) | 16.8 (3.3, 41.15) | 19.4 (10.0–54.13) | 0.314 |
| Procalcitonin, ug/L | 0.11 (0.10–0.14) | 0.10 (0.08–0.15) | 0.11 (0.06, 0.15) | 0.12 (0.10–0.14) | 0.256 |
| Fibrinogen, g/L | 3.2 (2.5–4.3) | 3.0 (2.5–4.3) | 3.2 (2.5–4.1) | 3.2 (2.5–4.4) | 0.549 |
| ALT, U/L | 28 (20–45) | 26.5 (20–39) | 26 (20–42) | 42 (19.7–52.7) | 0.126 |
| <40 | 65 (67.0%) | 21 (80.8%) | 35 (71.4%) | 9 (40.9%) | 0.009∗∗ |
| ≥40 | 32 (33.0%) | 5 (19.2%) | 14 (28.6%) | 13 (59.1%) | |
| AST, U/L | 30 (21.5–42) | 25.5 (20.5–34) | 28.0 (21–40) | 42.5 (22.75–64.5) | 0.004∗∗ |
| <40 | 70 (72.2%) | 24 (92.3%) | 38 (77.6%) | 3 (36.4%) | ≤0.001∗∗∗ |
| ≥40 | 27 (27.8%) | 2 (7.7%) | 11 (22.4%) | 14 (63.6%) | |
| AST/ALT | 1.04 (0.76–1.35) | 0.96 (0.60, 1.43) | 1.02 (0.73–1.30) | 1.30 (0.89, 1.71) | 0.108 |
| Total bilirubin, mmol/L | 9.60 (7.10–13.05) | 8.80 (6.13–12.10) | 9.20 (6.80–12.60) | 12.35 (9.38–14.75) | 0.046∗ |
| Albumin, g/L | 36.8 (33–39.8) | 37.60 (33.8–40) | 36.6 (33.4–39.9) | 36.2 (32.5–40) | 0.158 |
| <35 | 36 (37.1%) | 8 (30.8%) | 17 (34.7%) | 11 (50.0%) | 0.350 |
| ≥35 | 61 (62.9%) | 18 (69.2%) | 32 (65.3%) | 11 (50.0%) | |
| Glomerular filtration rate, (mL/min) | 99.5 (91–113.75) | 109.35 (94.8–119.7) | 105.3 (94.2–117.6) | 94.5 (80.3–97.4) | 0.001∗∗ |
| Carbon dioxide combining power, mmol/L | 26.8 (24.4–28.9) | 25.70 (24.4–28.3) | 27.2 (24.7–28.9) | 27 (23–28.9) | 0.428 |
| Creatine kinase, U/L | 72 (46–118) | 59 (42–100.3) | 72 (46–118) | 118 (59.3–353) | 0.203 |
| <185 | 83 (85.6%) | 25 (96.2%) | 43 (87.8%) | 15 (68.2%) | 0.022∗ |
| ≥185 | 14 (14.4%) | 1 (3.8%) | 6 (12.2%) | 7 (31.8%) | |
| Creatine kinase isoenzymes, CK-MB, ng/mL | 0.34 (0.16–0.73) | 0.29 (0.08–0.61) | 0.28 (0.13–0.69) | 0.57 (0.27–1.10) | 0.008∗∗ |
| <5 | 66 (68.0%) | 17 (65.4%) | 39 (79.6%) | 10 (45.5%) | 0.016∗∗ |
| ≥5 | 31 (32.0%) | 9 (34.6%) | 10 (20.4%) | 12 (54.5%) | |
| Myoglobin, μg/L | 45 (30–66) | 34 (27.5–50) | 38 (29–60.5) | 66 (49.5–187.5) | ≤0.001∗∗∗ |
| <100 | 84 (86.6%) | 24 (92.3%) | 46 (93.9%) | 14 (63.6%) | 0.004∗∗ |
| ≥100 | 13 (13.4%) | 2 (7.7%) | 3 (6.1%) | 8 (36.4%) | |
| Lactate, mmol/L | 1.2 (0.9–1.7) | 1.0 (0.9–1.2) | 1.24 (0.9–1.7) | 1.6 (1.2–1.9) | 0.004∗∗ |
| <1.7 | 69 (73.4%) | 22 (88.0%) | 37 (78.7%) | 10 (45.5%) | 0.02∗ |
| ≥1.7 | 25 (26.6%) | 3 (12.0%) | 10 (21.3%) | 12 (54.5%) | |
| PF ratio, mmHg | 433.5 (311.4–527.4) | 471.3 (293.5–530.8) | 446 (370.8–572.9) | 340 (223.4–447.4) | 0.02∗ |
| <300 | 20 | 7 | 4 | 9 | 0.003∗∗ |
| ≥300 | 77 | 19 | 45 | 13 | |
| Treatment | |||||
| Antibiotics | 30 (30.9%) | 11 (42.3%) | 13 (26.5%) | 6 (27.3%) | 0.340 |
| Antiviral treatment | 37 (38.1%) | 10 (38.5%) | 19 (38.8%) | 8 (36.4%) | 0.981 |
| Chinese medicine treatment | 74 (76.3%) | 22 (84.6%) | 36 (73.5%) | 16 (72.7%) | 0.505 |
| Corticosteroids | 19 (19.6%) | 0 (0.0%) | 8 (16.3%) | 11 (50.0%) | ≤0.001∗∗∗ |
| Oxygen therapy | 34 (35.1%) | 4 (15.4%) | 19 (38.8%) | 11 (50.0%) | 0.032∗ |
| Ventilator | 6 (6.2%) | 0 (0.0%) | 2 (4.1%) | 4 (18.2%) | 0.024∗ |
(a)Positive result: CT images showing multiple patchy ground-glass opacities along the peribronchial and subpleural lungs; NLR: neutrophil-to-lymphocyte ratio; LMR: lymphocyte-to-monocyte ratio; PLR: platelet-to-lymphocyte ratio; ALT: alanine aminotransferase; AST: aspartate aminotransferase; PF ratio: PaO2/FiO2 ratio. Significance codes: “∗∗∗”0.001, “∗∗”0.01, “∗”0.05.