Table 1.
Baseline characteristics of the study participants.
| Seronegative, n (%) | Seropositive, n (%) | OR (95% CI) | P-value | |
|---|---|---|---|---|
| Total | 7784 (97.8%) | 166 (2.1%) | ||
| Age (years), mean ± SD | 46.7 ± 11.9 | 48.9 ± 11.9 | 1.016 (1.002; 1.029) | 0.022 |
| Sex | ||||
| Female | 6803 (98.0%) | 142 (2.0%) | 1.00 (Ref.) | 0.477 |
| Male | 981 (97.6%) | 24 (2.4%) | 1.17 (0.76; 1.82) | |
| Body mass index (kg/m2) | ||||
| <25 | 4137 (98.2%) | 74 (1.8%) | 1.00 (Ref.) | 0.078 |
| 25–30 | 2290 (97.4%) | 61 (2.6%) | 1.49 (1.06; 2.10) | |
| ≥30 | 1255 (97.9%) | 27 (2.1%) | 1.20 (0.77; 1.88) | |
| PCR tested for SARS-CoV-2 | 1511 (95.2%) | 76 (4.8%) | 3.61 (2.64; 4.94) | <0.001 |
| ≥1 symptom of COVID-19 | 5419 (97.4%) | 143 (2.6%) | 2.71 (1.74; 4.23) | <0.001 |
| No symptoms | 2271 (99.1%) | 20 (0.9%) | 0.33 (0.21; 0.53) | <0.001 |
| Professional group | ||||
| Administrative staff | 1058 (97.9%) | 23 (2.1%) | 1.00 (Ref.) | |
| Assisting nurse | 435 (97.3%) | 12 (2.7%) | 1.27 (0.63; 2.57) | 0.509 |
| Laboratory technician | 516 (99.0%) | 5 (1.0%) | 0.45 (0.17; 1.18) | 0.104 |
| Logistics staff | 253 (96.6%) | 9 (3.4%) | 1.64 (0.75; 3.58) | 0.218 |
| Medical doctor | 950 (97.4%) | 25 (2.6%) | 1.21 (0.68; 2.15) | 0.513 |
| Medical student | 100 (100.0%) | 0 (0.0%) | - | - |
| Nurse | 2845 (97.6%) | 69 (2.4%) | 1.12 (0.69; 1.80) | 0.653 |
| Nursing student | 107 (100.0%) | 0 (0.0%) | - | - |
| Other staff with patient contact | 740 (98.7%) | 10 (1.3%) | 0.62 (0.29; 1.31) | 0.213 |
| Other staff without patient contact | 599 (98.2%) | 11 (1.8%) | 0.84 (0.41; 1.74) | 0.649 |
| PhD student | 31 (100.0%) | 0 (0.0%) | - | - |
| Prehospital staff | 70 (100.0%) | 0 (0.0%) | - | - |
OR, odds ratio; CI, confidence interval; SD, standard deviation.