Table 4 Characteristics of the study population
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 |