Table 1.
Demographic and clinical characteristics of the 175 subjects enrolled in this study
| Characteristic | Discovery cohort (n = 102) | Validation cohort (n = 73) | ||||||
|---|---|---|---|---|---|---|---|---|
| NSCAP (n = 38) | SCAP (n = 30) | Controls (n = 34) | p value | NSCAP (n = 32) | SCAP (n = 19) | Controls (n = 22) | p value | |
| Age (years) | 56.5 (45.8–64.5) | 58 (43–82.3) | 57 (46.3–62.5) | 0.647 | 28 (23.3–43) | 64 (54–74) | 40.5 (30.8–49.3) | < 0.001 |
| Sex, male | 23 (60.5) | 23 (76.7) | 21 (61.8) | 0.319 | 16 (50.0) | 15 (78.9) | 12 (54.5) | 0.112 |
| Smoking history | 7 (18.4) | 2 (6.7) | 8 (23.5) | 0.209 | 2 (6.3) | 3 (15.8) | 4 (18.2) | 0.354 |
| Underlying diseases | ||||||||
| Respiratory diseases | 1 (2.6) | 0 (0) | 1 (2.9) | 1.000 | 0 (0) | 4 (21.1) | 0 (0) | 0.004 |
| Cardiovascular diseases | 3 (7.9) | 6 (20.0) | 9 (26.5) | 0.122 | 0 (0) | 5 (26.3) | 1 (4.5) | 0.002 |
| Liver diseases | 1 (2.6) | 2 (6.7) | 1 (2.9) | 0.681 | 0 (0) | 0 (0) | 0 (0) | NA |
| Neurological diseases | 3 (7.9) | 4 (13.3) | 2 (5.9) | 0.621 | 0 (0) | 3 (15.8) | 0 (0) | 0.016 |
| Hyperlipidaemia | 1 (2.6) | 1 (3.3) | 4 (11.8) | 0.315 | 0 (0) | 1 (5.3) | 0 (0) | 0.260 |
| Infected pathogens | ||||||||
| Bacterial | 6 (15.8) | 10 (33.3) | NA | 0.090 | 9 (28.1) | 7 (36.8) | NA | 0.547 |
| Viral | 3 (7.9) | 7 (23.3) | NA | 0.094 | 2 (6.3) | 3 (15.8) | NA | 0.348 |
| Atypical pathogens | 6 (15.8) | 2 (6.7) | NA | 0.288 | 11 (34.4) | 2 (10.5) | NA | 0.096 |
| WBC (×109/L) | 7.4 (5.6–10.8) | 7.7 (5.1–10.6) | NA | 0.946 | 5.6 (4.4–7.5) | 10.7 (7.1–15.6) | NA | 0.001 |
| NE% | 66.4 (56.0–81.3) | 83.5 (78.3–90.4) | NA | < 0.001 | 67.1 (63.7–77.3) | 84.1 (78.8–91.6) | NA | 0.002 |
| ESR (mm/h) | 47.0 (41.5–51.5) | 60.0 (43.0–66.3) | NA | 0.082 | 27.0 (17.5–45.0) | 65.0 (35.0–79.0) | NA | 0.009 |
| CRP (mg/l) | 51.5 (49.0–121.8) | 123.0 (83.4–141.0) | NA | 0.013 | 55.3 (22.3–82.0) | 111.0 (60.6–196.5) | NA | 0.008 |
| PCT (μg/L) | 0.2 (0.1–1.3) | 0.5 (0.2–3.7) | NA | 0.086 | 0.1 (0.1–0.2) | 0.9 (0.4–3.1) | NA | 0.009 |
| PaO2/FiO2 | 379.5 (306.3–403.5) |
197.5 (172.8–252.3) |
NA | < 0.001 | 378.0 (358.0–390.8) |
187.0 (153.0–219.0) |
NA | < 0.001 |
| CURB-65 score | 0 (0-1) | 1 (0-2) | NA | < 0.001 | 0 (0-0) | 1 (1–2) | NA | < 0.001 |
| PSI score | 59.5 (46.8–76.0) | 86.5 (59.3–120.8) | NA | 0.001 | 35.5 (25.0–54.5) | 87.0 (60.0–118.0) | NA | < 0.001 |
| APACHE II score | 4 (3-6) | 11.5 (7-16) | NA | < 0.001 | 3 (2-5) | 10 (6–15) | NA | < 0.001 |
| Drug treatment | ||||||||
| Antibiotics | 37 (97.4) | 30 (100) | NA | 1.000 | 32 (100) | 19 (100) | NA | NA |
| Antiviral drugs | 2 (5.3) | 12 (40.0) | NA | 0.001 | 2 (6.3) | 4 (21.1) | NA | 0.179 |
| Corticosteroids | 2 (5.3) | 7 (23.3) | NA | 0.037 | 1 (3.1) | 4 (21.1) | NA | 0.058 |
| Vasopressors | 0 (0) | 8 (26.7) | NA | 0.001 | 0 (0) | 5 (26.3) | NA | 0.005 |
| Non-invasive ventilation | 0 (0) | 16 (53.3) | NA | < 0.001 | 2 (6.3) | 9 (47.4) | NA | < 0.001 |
| Invasive ventilation | 0 (0) | 11 (36.7) | NA | < 0.001 | 0 (0) | 5 (26.3) | NA | < 0.001 |
| ECMO | 0 (0) | 1 (3.3) | NA | 0.441 | 0 (0) | 0 (0) | NA | NA |
| Sepsis | 0 (0) | 11 (36.7) | NA | < 0.001 | 0 (0) | 9 (47.4) | NA | < 0.001 |
| Hospital LOS (days) | 11.0 (7.8–14.0) | 17.5 (12.8–22.0) | NA | < 0.001 | 11.5 (8.0–13.8) | 15.0 (11.0–24.0) | NA | 0.005 |
| ICU admission | 0 (0) | 15 (50) | NA | < 0.001 | 0 (0) | 6 (31.6) | NA | 0.002 |
| In-hospital mortality | 0 (0) | 7 (23.3) | NA | 0.002 | 0 (0) | 3 (15.8) | NA | < 0.001 |
| 30-day mortality | 0 (0) | 7 (23.3) | NA | 0.002 | 0 (0) | 2 (10.5) | NA | < 0.001 |
Data presented as number (percentage) or median (interquartile range)
CAP community-acquired pneumonia, NSCAP non-severe CAP, SCAP severe CAP, WBC white blood cell, NE% percentage of neutrophils, ESR erythrocyte sedimentation rate, CRP C-reactive protein, PCT procalcitonin, PaO2/FiO2 ratio of arterial oxygen tension to inspired oxygen fraction, CURB-65 confusion, urea level, respiratory rate, blood pressure, and age > 65 years, PSI pneumonia severity index, APACHE II Acute Physiology and Chronic Health Evaluation II, ECMO extracorporeal membrane oxygenation, LOS length of stay, ICU intensive care unit, NA not applicable