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Table 4 Characteristics of the study population

From: Development of machine learning models to predict RT-PCR results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with influenza-like symptoms using only basic clinical data

Demographic characteristics Overall
population (n = 199)
Positive
(n = 124)
Negative
(n = 75)
P
Age, years 65 [46–78] 65 [49–77] 66 [38–82] 0.94
Male ̶ no. (%) 127 (63.8) 78 (62.9) 49 (65.3) 0.85
Medical History ̶ no. (%)
 Asthma 13 (6.6) 9 (7.3) 4 (5.4) 0.83
 Atrial fibrillation 19 (9.6) 11 (8.9) 8 (10.7) 0.87
 Autoimmune/inflammatory disease 6 (3.0) 3 (2.4) 3 (4) 0.84
 Chronic Interstitial lung disease 1 (0.5) 1 (0.8) 0 (0.0) 0.80
 Chronic kidney disease 11 (5.5) 8 (6.5) 3 (4.0) 0.68
 Chronic liver disease 7 (3.5) 3 (2.4) 4 (5.3) 0.49
 Chronic obstructive pulmonary disease 15 (7.5) 5 (4.0) 10 (13.3) 0.03
 Diabetes mellitus 29 (14.6) 16 (12.9) 13 (17.3) 0.51
 Hematologic malignancy 6 (3.0) 4 (3.2) 2 (2.7) 0.84
 Human immunodeficiency virus 1 (0.5) 0 (0.0) 1 (1.3) 0.80
 Hypertension 85 (42.7) 55 (44.4) 30 (40) 0.65
 Ischemic cardiomyopathy 19 (9.6) 10 (8.1) 9 (12.0) 0.51
 Smoking (active) 12 (6.0) 4 (3.2) 8 (10.7) 0.07
 Solid organ tumour 16 (8.0) 7 (5.7) 9 (12.0) 0.18
Medication history ̶ no. (%)
 5-alpha-reductase inhibitors 12 (6.0) 9 (7.3) 3 (4.0) 0.53
 Angiotensin converting enzyme inhibitors 33 (16.6) 21 (16.9) 12 (16.0) 0.98
 Anti-arrhythmic drugs 11 (5.5) 6 (4.8) 5 (6.7) 0.82
 Antibiotics before Emergency Department 47 (23.6) 36 (29.0) 11 (14.7) 0.03
 Anticoagulant drugs 25 (12.6) 15 (12.1) 10 (13.3) 0.97
 Anti-epileptic drugs 10 (5.0) 1 (0.8) 9 (12.0) 0.002
 Antiplatelets drugs 33 (16.6) 20 (16.1) 13 (17.3) 0.98
 Beta blockers 40 (20.1) 24 (19.4) 16 (21.3) 0.88
 Calcium channel antagonists 27 (13.6) 18 (14.5) 9 (12.0) 0.77
 Diuretics 35 (17.6) 21 (16.9) 14 (18.7) 0.91
 Drugs for psychiatric disorders 7 (3.5) 1 (0.8) 6 (8.0) 0.02
 Hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors 28 (14.1) 18 (14.5) 10 (13.3) 0.98
 Immunosuppressant drugs 12 (6.0) 8 (6.5) 4 (5.3) 0.99
 Sartans 24 (12.1) 19 (15.3) 5 (6.7) 0.11
Reported Signs and Symptoms - no. (%)
 Arthralgia 7 (3.5) 6 (4.8) 1 (1.3) 0.37
 Asthenia 18 (9.1) 9 (7.3) 9 (12.0) 0.38
 Chest pain 7 (3.5) 7 (5.7) 0 (0.0) 0.09
 Cough 130 (65.3) 91 (73.4) 39 (52) 0.004
 Dyspnea 75 (37.7) 43 (34.7) 32 (42.7) 0.33
 Fever 174 (87.4) 119 (96.0) 55 (73.3) < 0.001
 Gastrointestinal symptoms 27 (13.6) 18 (14.5) 9 (12.0) 0.77
 Headache 12 (6.0) 8 (6.5) 4 (5.3) 0.99
 Sore throat 8 (4.0) 3 (2.4) 5 (6.7) 0.27
 Syncope 5 (2.5) 2 (1.6) 3 (4.0) 0.57
Vital signs, ECG and Chest X-ray findings
 Glasgow coma scale, score 15 [15–15] 15 [15–15] 15 [15–15] > 0.99
 Body temperature, Celsius 37.6 ± 0.9 37.8 ± 0.8 37.2 ± 1 < 0.001
 Systolic blood pressure, mmHg 131 ± 22 133 ± 19 128 ± 25 0.09
 Diastolic blood pressure, mmHg 75 [65–80] 75 [70–80] 70 [65–80] 0.09
 Heart rate, beats per min 90 [80–105] 90 [83–105] 90 [80–105] 0.87
 Sinus rhythm ̶ no. (%) 185 (93) 117 (94.4) 68 (90.7) 0.48
 Normal ST segment ̶ no. (%) 198 (99.5) 123 (99.2) 75 (100.0) 0.80
 Respiratory rate, breaths per min 18 [16–22] 18 [16–22] 18 [16–24] 0.80
 Oxygen supplementation ̶ no. (%) 51 (25.6) 27 (21.8) 24 (32.0) 0.15
 Non-Invasive Ventilation ̶ no. (%) 8 (4.0) 4 (3.2) 4 (5.3) 0.72
 Chest X-rays opacity ̶ no. (%) 158 (79.4) 104 (83.9) 54 (72.0) 0.07
 Chest X-rays pleural effusion ̶ no. (%) 20 (10.1) 7 (5.7) 13 (17.3) 0.01
Laboratory findings
 Total white blood cell count, 103/μL 6.64 [4.65–9.65] 5.44 [4.21–7.23] 9.28 [6.87–13.64] < 0.001
 Neutrophils, % 72.5 [64.4–81.7] 70.4 [62.5–79.9] 76.7 [68.4–85.3] 0.001
 Lymphocytes, % 18.0 [10.5–25.1] 20.6 [12.9–27.7] 14.5 [7.4–19.8] < 0.001
 Monocytes, % 7.9 [5.6–10.2] 8.0 [6–10.9] 7.6 [5.4–9.7] 0.18
 Eosinophils, % 0 [0–0.3] 0 [0–0.2] 0.2 [0–1.2] < 0.001
 Basophils, % 0.3 [0.2–0.4] 0.2 [0.2–0.4] 0.3 [0.2–0.5] 0.03
 Total red blood cells count, 106/μL 4.80 [4.29–5.25] 4.88 [4.42–5.28] 4.52 [4.01–5.14] 0.01
 Haematocrit, % 41.6 ± 5.3 42.1 ± 4.5 40.8 ± 6.3 0.10
 Haemoglobin, g/dL 13.7 ± 1.9 14.0 ± 1.6 13.3 ± 2.2 0.01
Mean corpuscular haemoglobin concentration, g/dL 33.1 [32–33.9] 33.2 [32.5–34.1] 32.8 [31.6–33.8] 0.01
Mean corpuscular haemoglobin, pg 29.2 [28.1–30.5] 29.2 [27.9–30.5] 29.3 [28.6–30.2] 0.56
Mean red blood cell volume, μm3 88.3 [85.4–91.4] 87.7 [84.5–90.4] 89.7 [87–92.6] 0.002
Red blood cells distribution width,% 13.2 [12.4–14.4] 13.1 [12.3–13.9] 13.6 [12.5–15.5] 0.01
Platelets, 103/μL 193 [162–244] 183 [145–234] 221 [175–283] < 0.001
Glycaemia, mg/dL 120 [104–142] 120 [104–138] 117 [101–158] 0.80
Creatinine, mg/dL 1.0 [0.8–1.3] 0.98 [0.82–1.21] 1.09 [0.83–1.45] 0.19
Urea, mg/dL 35 [23–54.5] 34 [22–49] 41.5 [26–64.5] 0.07
Sodium, mEq/L 138 [135–140] 138 [134–140] 138 [136–141] 0.37
Total bilirubin, mg/dL 0.5 [0.4–0.7] 0.5 [0.3–0.6] 0.5 [0.4–0.7] 0.05
C-reactive protein, mg/dL 4.1 [1.2–9] 4.0 [1.3–8.9] 4.5 [0.9–9.3] 0.90
  1. Variables are ordered by categories. Continuous variables are expressed as median [interquartile range] or mean ± Standard Deviation, as appropriate. Medical and medication history, reported signs and symptoms were collected from physicians of the Emergency Department. Clinical findings (Vital signs, ECG – Electrocardiogram, Chest X-ray and Laboratory findings) refer to the first measurements performed in the Emergency department