Table 1 Baseline characteristics of included patients classified by cluster
From: Unsupervised machine learning clustering approach for hospitalized COVID-19 pneumonia patients
Variables | All (N = 538) | Cluster 1 (N = 27) | Cluster 2 (N = 370) | Cluster 3 (N = 141) | P-value |
|---|---|---|---|---|---|
Age, years | 56.3 ± 18.7 | 53.4 ± 15 | 52.1 ± 18.7 | 67.7 ± 14.2 | < 0.001 |
Male, N (%) | 250 (46.5) | 19 (70.4) | 156 (42.2) | 75 (53.2) | 0.003 |
Ever smoking, N (%) | 72 (13.4) | 3 (11.1) | 49 (13.2) | 20 (14.2) | 0.90 |
BMI, kg/m2 | 27.0 ± 6.5 | 26.9 ± 5.4 | 27.7 ± 6.9 | 25.1 ± 5.1 | < 0.001 |
Vital signs | |||||
Body temperature, °C | 36.8 ± 0.5 | 36.8 ± 0.4 | 36.7 ± 0.4 | 37.0 ± 0.7 | < 0.001 |
Respiratory rate, times/min | 22.4 ± 3.8 | 22.1 ± 2.5 | 21.4 ± 2.7 | 24.8 ± 5.3 | < 0.001 |
Heart rate, beats/min | 88.4 ± 15.4 | 90.5 ± 16.4 | 88.4 ± 15.1 | 88.0 ± 15.8 | 0.75 |
Mean arterial pressure, mm Hg | 100.7 ± 14.0 | 103.2 ± 15.0 | 102.5 ± 12.6 | 95.6 ± 16.0 | < 0.001 |
SpO2% at ambient air | 96.4 ± 2.9 | 95.9 ± 2.6 | 97.3 ± 1.3 | 94.1 ± 4.3 | < 0.001 |
Number of vaccinations, N (%) | 0.16 | ||||
No vaccination | 334 (62.1) | 20 (74.1) | 227 (61.4) | 87 (61.7) | |
1 dose of vaccination | 141 (26.2) | 3 (11.1) | 95 (25.7) | 43 (30.5) | |
2 dose of vaccination | 63 (11.7) | 4 (13.8) | 48 (13.0) | 11 (7.8) | |
Comorbid disease, N (%) | |||||
Diabetes mellitus | 159 (29.6) | 4 (14.8) | 82 (22.2) | 73 (51.8) | < 0.001 |
Ischemic heart disease | 34 (6.3) | 0 (0) | 18 (4.9) | 16 (11.3) | 0.01 |
Chronic lung diseases | 35 (6.5) | 1 (3.7) | 22 (5.9) | 12 (8.5) | 0.48 |
Cerebrovascular diseases | 26 (4.8) | 3 (11.1) | 13 (3.5) | 10 (7.1) | 0.07 |
Immunocompromised patients | 29 (5.4) | 2 (7.4) | 17 (4.6) | 10 (7.1) | 0.48 |
Cancer | 28 (5.2) | 2 (7.4) | 15 (4.1) | 11 (7.8) | 0.20 |
Chronic renal failure | 53 (9.9) | 1 (3.7) | 16 (4.3) | 36 (25.5) | < 0.001 |
Symptoms | |||||
Fever | 309 (57.4) | 14 (51.9) | 213 (57.6) | 82 (58.2) | 0.83 |
Chest pain | 25 (4.6) | 2 (7.4) | 18 (4.9) | 5 (3.5) | 0.64 |
Dyspnea | 82 (15.2) | 6 (22.2) | 50 (13.6) | 26 (18.4) | 0.22 |
Cough | 409 (76.0) | 18 (66.7) | 275 (74.3) | 116 (82.3) | 0.09 |
Headache | 88 (16.4) | 2 (7.4) | 73 (19.7) | 13 (9.2) | 0.007 |
Sputum | 179 (33.3) | 8 (29.6) | 117 (31.6) | 54 (38.3) | 0.33 |
Sore throat | 148 (27.5) | 3 (11.1) | 107 (28.9) | 38 (27.0) | 0.13 |
Muscle ache | 152 (28.3) | 9 (33.3) | 113 (30.5) | 30 (21.3) | 0.10 |
Rhinorrhea | 169 (11.4) | 5 (18.5) | 131 (35.4) | 33 (23.4) | 0.01 |
Gastrointestinal symptom | 102 (19.0) | 7 (25.9) | 66 (17.8) | 29 (20.6) | 0.50 |
Chest X-ray score | 2.6 ± 1.6 | 2.9 ± 1.3 | 2.0 ± 0.9 | 4.2 ± 2.0 | < 0.001 |
CT ratio of PCR for COVID − 19 | 20.38 ± 6.15 | 20.55 ± 5.70 | 19.76 ± 6.01 | 21.96 ± 6.33 | 0.001 |
CBC | |||||
Hemoglobin, g/dl | 13.1 ± 2.0 | 13.6 ± 2.1 | 13.5 ± 1.7 | 11.9 ± 2.2 | < 0.001 |
Hematocrit, % | 39.9 ± 5.9 | 41.0 ± 6.3 | 41.2 ± 5.1 | 36.1 ± 6.3 | < 0.001 |
White blood cell counts, cells/mm3 | 5823 ± 2807 | 5219 ± 2607 | 5633 ± 2374 | 6435 ± 3681 | 0.008 |
Lymphocyte counts, cells/mm3 | 1561 ± 931 | 1276 ± 743 | 1755 ± 977 | 1108 ± 617 | < 0.001 |
Platelets count, 103/mm3 | 246.7 ± 97.7 | 275.9 ± 141.2 | 250.3 ± 81.9 | 231.7 ± 121.8 | 0.04 |
Liver function test | |||||
AST, IU/L | 45.4 ± 36.8 | 142.8 ± 68.9 | 34.6 ± 18.0 | 54.8 ± 29.5 | < 0.001 |
ALT, IU/L | 41.0 ± 38.4 | 156.3 ± 76.7 | 33.7 ± 21.0 | 38.2 ± 26.0 | < 0.001 |
ALP, IU/L | 83.7 ± 43.5 | 172.8 ± 92.2 | 47.8 ± 25.6 | 90.0 ± 46.6 | < 0.001 |
GGT, IU/L† | 50.5 (28-100) | 441 (246-615) | 45 (27-80) | 57 (29-111) | < 0.001 |
Total bilirubin, mg/dL † | 0.4 (0.3–0.6) | 0.6(0.5–0.8) | 0.4(0.3–0.6) | 0.5(0.4–0.8) | < 0.001 |
Direct bilirubin, mg/dL † | 0.2 (0.2–0.3) | 0.3(0.3–0.4) | 0.2(0.2–0.3) | 0.3(0.2–0.4) | < 0.001 |
Albumin, g/dL | 4.2 ± 0.4 | 4.2 ± 0.5 | 4.3 ± 0.3 | 3.7 ± 0.4 | < 0.001 |
Total protein, g/dL | 7.1 ± 0.6 | 7.6 ± 0.6 | 7.7 ± 0.5 | 7.1 ± 0.6 | < 0.001 |
Renal function | |||||
Creatinine, mg/dL † | 0.87 (0.72-1.08) | 0.85 (0.70-1.16) | 0.83 (0.70-1.00) | 1.01 (0.81-1.48) | < 0.001 |
Blood urine nitrogen, mg/dL † | 12 (9–16) | 12 (9–15) | 11 (9–14) | 17 (12–29) | < 0.001 |
HbA1c, mg% | 6.25 ± 1.68 | 5.76 ± 0.76 | 6.14 ± 1.63 | 6.64 ± 1.87 | 0.003 |
D-dimers, ng/ml † | 527.5 (321–870) | 575 (340–1113) | 433 (281–672) | 850 (487–1519) | < 0.001 |
C-reactive protein, mg/dL † | 18.8 (5.9–45.3) | 23.9 (14.2–84) | 11.9 (3.8–26.5) | 61.2 (33.1–108) | < 0.001 |
Lactate dehydrogenase, U/L | 246.1 ± 96.9 | 340.7 ± 134.9 | 209.5 ± 57.9 | 324.1 ± 111.7 | < 0.001 |