Baseline characteristics of patients admitted to hospital during the Omicron wave with acute COVID-19, by SARS-CoV-2 vaccination status
| Variable | Vaccination status* | p value | ||
|---|---|---|---|---|
| No. (%)† of all patients n = 441 | No. (%)† of unvaccinated patients n = 130 | No. (%)† of patients with ≥ 2 doses n = 242 | ||
| Sex | 0.528 | |||
| Unknown, n | 1 | 1 | 0 | – |
| Male | 261 (59.3) | 74 (57.4) | 147 (60.7) | – |
| Female | 179 (40.7) | 55 (42.6) | 95 (39.3) | – |
| Age, mean ± SD | 70.1 ± 15.2 | 67.9 ± 15.0 | 71.2 ± 15.3 | 0.046 |
| Received any SARS-CoV-2 vaccine before admission | 261/391 (66.8) | – | – | – |
| Received at least 2 doses of SARS-CoV-2 vaccine before admission | 242/390 (62.1) | – | – | – |
| Admitted to ICU on hospital admission day | 64 (14.5) | 29 (22.5) | 25 (10.3) | 0.002 |
| Organ support on admission day | ||||
| Invasive mechanical ventilation | 20/441 (4.5) | 10/130 (7.7) | 7/242 (2.9) | 0.035 |
| RRT or dialysis | 8/439 (1.8) | 1/129 (0.8) | 6/241 (2.5) | 0.429 |
| Vasopressors | 18/440 (4.1) | 8/129 (6.2) | 6/242 (2.5) | 0.073 |
| Temperature (°C), mean ± SD | 37.1 ± 0.9 | 37.1 ± 1.0 | 37.1 ± 0.9 | 0.830 |
| Missing, n | 16 | 8 | 5 | – |
| Heart rate (beats/min), mean ± SD | 92.6 ± 21.5 | 93.3 ± 22.7 | 91.1 ± 20.3 | 0.352 |
| Missing, n | 2 | 1 | 1 | – |
| Respiratory rate (breaths/min), mean ± SD | 23.2 ± 7.7 | 24.0 ± 9.3 | 22.7 ± 6.6 | 0.118 |
| Missing, n | 12 | 5 | 4 | – |
| sBP, mean ± SD | 131.2 ± 26.9 | 127.7 ± 24.3 | 133.6 ± 29.0 | 0.054 |
| Missing, n | 7 | 5 | 0 | – |
| dBP, mean ± SD | 72.5 ± 13.9 | 72.3 ± 13.3 | 72.7 ± 14.0 | 0.776 |
| Missing, n | 10 | 6 | 1 | – |
| Oxygen saturation (Sao2; %), mean ± SD | 93.1 ± 6.7 | 91.7 ± 7.8 | 93.6 ± 6.5 | 0.014 |
| Missing, n | 5 | 2 | 0 | – |
| Required oxygen therapy | 147/426 (34.5) | 49/127 (38.6) | 79/234 (33.8) | 0.360 |
| Leukocyte count (× 103/μL), median IQR | 7.3 (5.1–9.9) | 6.8 (4.6–9.5) | 7.5 (5.2–10.0) | 0.064 |
| Missing, n | 3 | 2 | 1 | – |
| Hemoglobin (g/L), median IQR | 127 (111–141) | 136 (124–146) | 120 (107–138) | < 0.001 |
| Missing, n | 3 | 2 | 1 | – |
| Creatinine (μmol/L), median IQR | 95.0 (70.0–136.0) | 90.5 (66.5–112.0) | 104.0 (74.0–154.0) | 0.001 |
| Missing, n | 4 | 2 | 1 | – |
| ALT (U/L), median IQR | 23.0 (16.0–38.0) | 28.0 (17.0–45.5) | 21.0 (15.0–34.0) | 0.007 |
| Missing | 122 | 30 | 73 | – |
| AST (U/L), median IQR | 38.5 (23.0–59.0) | 50.0 (37.0–80.0) | 29.0 (22.0–59.0) | 0.006 |
| Missing | 343 | 99 | 191 | – |
Note: ALT = alanine aminotransferase, AST = aspartate transferase, dBP = diastolic blood pressure, ICU = intensive care unit, IQR = interquartile range, RRT = renal replacement therapy, sBP = systolic blood pressure, SD = standard deviation.
↵* Patients who received only a single dose of vaccine (n = 18) or with uncertain vaccination status (n = 51) were excluded from the stratified summary.
↵† Unless otherwise indicated.