TABLE 1.
Baseline characteristics of COVID-19 patients on admission to the general ward
| Age decade | p-value | ||||
| <50 years (n=89) | ≥50– <60 years (n=111) | ≥60– <70 years (n=135) | ≥70 years (n=129) | ||
| Demographics | |||||
| Age, years | 44 (37–47) | 55 (53–57) | 64 (62–67) | 76 (72–82) | <0.001 |
| Male | 49 (55.1) | 68 (61.3) | 83 (61.5) | 78 (60.5) | 0.784 |
| BMI, kg·m−2 | 30.0 (27.4–33.2) | 27.8 (25.2–32.1) | 28.7 (25.6–32.8) | 27.5 (24.3–30.1) | 0.002 |
| Duration of symptoms#, days | 8 (7–10) | 9 (7–11) | 8 (6–11) | 8 (5–10) | 0.109 |
| Smoking status | 0.009 | ||||
| Current smoker | 4 (4.5) | 4 (3.6) | 8 (5.9) | 8 (6.2) | |
| Ex-smoker | 17 (19.1) | 27 (24.3) | 48 (35.6) | 53 (41.1) | |
| Never-smoker | 60 (67.4) | 70 (63.1) | 73 (54.1) | 55 (42.6) | |
| Unknown | 8 (9.0) | 10 (9.0) | 6 (4.4) | 13 (10.1) | |
| COVID-19 vaccination status | 0.262 | ||||
| Yes | 2 (2.2) | 2 (1.8) | 8 (5.9) | 7 (5.4) | |
| No | 86 (96.6) | 106 (95.5) | 120 (88.9) | 119 (92.2) | |
| Unknown | 1 (1.1) | 3 (2.7) | 7 (5.2) | 3 (2.3) | |
| Comorbidities and (selected) chronic medication | |||||
| Charlson score¶ | 0.0 (0–1.0) | 1.0 (1.0–2.0) | 3.0 (2.0–4.0) | 4.0 (4.0–6.0) | <0.001 |
| Hypertension | 17 (19.1) | 32 (28.8) | 64 (47.4) | 68 (52.7) | <0.001 |
| Cardiac disease | 13 (14.6) | 16 (14.4) | 44 (32.6) | 51 (39.5) | <0.001 |
| Respiratory disease | 14 (15.7) | 20 (18.0) | 25 (18.5) | 33 (25.6) | 0.261 |
| Diabetes | 19 (21.3) | 13 (11.7) | 35 (25.9) | 41 (31.8) | 0.003 |
| Kidney disease | 5 (5.6) | 4 (3.6) | 8 (5.9) | 19 (14.7) | 0.005 |
| Neurological disease | 5 (5.6) | 3 (2.7) | 9 (6.7) | 21 (16.3) | 0.001 |
| Prior malignancy | 3 (3.4) | 1 (0.9) | 13 (9.6) | 14 (10.9) | 0.005 |
| Immunosuppression+ | 10 (11.2) | 4 (3.6) | 16 (11.9) | 5 (3.9) | 0.016 |
| Antiplatelet drugs | 1 (1.1) | 5 (4.5) | 28 (20.7) | 19 (14.7) | <0.001 |
| Anticoagulant drugs | 5 (5.6) | 4 (3.6) | 7 (5.2) | 24 (18.6) | <0.001 |
| Disease severity on admission | |||||
| 4C Mortality§ | 4 (3–5) | 3 (2–5) | 4 (3–6) | 6 (4–7) | <0.001 |
| qSOFA | 1 (0–1) | 1 (0–1) | 1 (0–1) | 1 (0–1) | 0.002 |
| MEWS | 3 (2–4) | 3 (2–4) | 3 (2–4) | 3 (2–4) | 0.102 |
| CURBƒ | 0 (0–1) | 0 (0–1) | 0 (0–1) | 1 (0–1) | <0.001 |
| Treatment at day of admission | |||||
| Supplementary oxygen therapy | 80 (89.9) | 103 (92.8) | 121 (89.6) | 115 (89.1) | 0.784 |
| High-flow nasal cannula | 0 (0.0) | 0 (0.0) | 2 (1.5) | 2 (1.6) | 0.382 |
| Noninvasive ventilation | 1 (1.1) | 0 (0.0) | 2 (1.5) | 1 (0.8) | 0.647 |
| Routine laboratory markers | |||||
| Leukocyte count, ×109 L−1 | 6.1 (4.6–8.3) | 6.0 (4.8–8.6) | 6.4 (4.9–7.9) | 6.9 (5.2–8.6) | 0.306 |
| Neutrophil count, ×109 L−1 | 4.8 (3.3–5.9) | 4.4 (3.2–6.6) | 5.0 (3.4–6.3) | 5.2 (3.9–6.9) | 0.074 |
| Lymphocyte count, ×109 L−1 | 1.00 (0.70–1.20) | 0.97 (0.70–1.20) | 0.93 (0.70–1.20) | 0.75 (0.50–1.05) | 0.001 |
| Neutrophil/lymphocyte ratio | 4.8 (2.8–7.2) | 4.5 (2.9–8.6) | 4.8 (3.3–7.5) | 6.4 (4.1–10.5) | 0.002 |
| C-reactive protein, mg·L−1 | 98 (49–126) | 76 (43–136) | 83 (51–141) | 100 (57–147) | 0.369 |
| Platelet count, ×109 L−1 | 220 (184–255) | 225 (181–276) | 215 (149–281) | 207 (151–266) | 0.434 |
| Creatinine, µmol·L−1 | 74 (63–92) | 79 (65–90) | 82 (67–101) | 87 (70–113) | 0.001 |
Data are presented as median (interquartile range) or n (%), unless otherwise stated. BMI: body mass index; qSOFA: quick Sequential Organ Failure Assessment; MEWS: Modified Early Warning Score; CURB: confusion, urea >7 mmol·L−1, respiratory rate ≥30 breaths·min−1, blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic). #: prior to admission; ¶: Charlson score was calculated without the age component; +: defined as a history of an organ transplant, immune deficiency or chronic use of immunosuppressants (see supplementary table S7 for details); §: 4C Mortality, a validated COVID-19 score [26], was calculated without the age and obesity component; ƒ: CURB score was calculated without the age component.