Table 4.
Association of covariates with RT-PCR status for SARS-CoV-2, following propensity score matching and binomial logistic regression
| SARS-CoV-2 RT-PCR | |||||||
| Negative | Positive | OR (univariable) | OR (multivariable) | ||||
| n | 312 | 548 | |||||
| Chest X-ray report | Alternative pathology (%) | 3 (0.8) | 3 (0.5) | – | – | ||
| No abnormalities (%) | 123 (39.6) | 104 (19.1) | 0.76 | (0.08–6.82, p=0.801) | 0.48 | (0.03–8.82, p=0.620) | |
| Indeterminate/atypical findings (%) |
61 (19.5) | 136 (4.8) | 1.99 | (0.22–17.81, p=0.535) | 0.92 | (0.05–16.88, p=0.952) | |
| Classic COVID-19 (%) | 125 (40.1) | 305 (55.6) | 2.17 | (0.24–19.19, p=0.484) | 1.14 | (0.06–20.98, p=0.927) | |
| Age | Mean (SD) | 61.8 (17.9) | 67.0 (17.7) | 1.02 | (1.01–1.02, p<0.001)** | 1.02 | (1.00–1.03, p=0.028)* |
| Sex | Female (%) | 138 (44.3) | 212 (38.7) | – | – | ||
| Male (%) | 174 (55.7) | 336 (61.3) | 1.26 | (0.93–1.70, p=0.137) | 1.19 | (0.83–1.71, p=0.340) | |
| Ethnicity | Other Asian (%) | 31 (9.9) | 66 (12.0) | – | |||
| White (%) | 164 (52.7) | 270 (49.2) | 0.76 | (0.44–1.31, p=0.326) | 0.73 | (0.38–1.40, p=0.339) | |
| Black (%) | 39 (12.4) | 84 (15.3) | 1.01 | (0.52–1.98, p=0.974) | 0.92 | (0.43–1.97, p=0.827) | |
| Mixed (%) | 6 (1.8) | 4 (0.8) | 0.36 | (0.08–1.62, p=0.184) | 0.74 | (0.11–4.94, p=0.754) | |
| South Asian (%) | 22 (7.0) | 36 (6.6) | 0.77 | (0.34–1.76, p=0.531) | 0.68 | (0.28–1.65, p=0.390) | |
| Other (%) | 51 (16.2) | 89 (16.2) | 0.82 | (0.43–1.55, p=0.535) | 0.88 | (0.45–1.74, p=0.716) | |
| Comorbidity | No (%) | 65 (20.8) | 95 (17.4) | – | – | ||
| Yes (%) | 247 (79.2) | 453 (82.6) | 1.25 | (0.82–1.89, p=0.296) | 1 | (0.53–1.88, p=0.993) | |
| Dyspnoea on attendance | No (%) | 90 (28.8) | 139 (25.4) | – | – | ||
| Yes (%) | 222 (71.2) | 409 (74.6) | 1.19 | (0.82–1.73, p=0.356) | 0.84 | (0.53–1.32, p=0.447) | |
| Oxygen saturation | Median (IQR) | 96 (6) | 93 (8) | 0.94 | (0.91–0.97, p<0.001** | 0.97 | (0.93–1.00, p=0.072) |
| Respiratory rate | Median (IQR) | 23 (8) | 25 (8) | 1.04 | (1.01–1.07, p=0.002)* | 1.01 | (0.98–1.05, p=0.462) |
| Glasgow Coma Scale | Median (IQR) | 15 (0) | 15 (0) | 1.02 | (0.89–1.17, p=0.819) | 1.21 | (0.98–1.48, p=0.073) |
| Temperature | Mean (SD) | 37.2 (1.4) | 37.7 (1.1) | 1.48 | (1.26–1.73, p<0.001)** | 1.44 | (1.20–1.74, p<0.001)** |
| Heart rate | Mean (SD) | 96.7 (20.5) | 94.9 (21.5) | 1 | (0.99–1.00, p=0.305) | 1 | (0.99–1.01, p=0.702) |
| Systolic blood pressure | Mean (SD) | 136.2 (25.8) | 132.6 (24.5) | 0.99 | (0.99–1.00, p=0.086) | 0.99 | (0.98–1.00, p=0.097) |
| Neutrophils | Median (IQR) | 6.26 (4.52) | 5.05 (3.93) | 0.92 | (0.89–0.96, p<0.001)** | 0.87 | (0.82–0.91, p<0.001)** |
| D-dimer | Median (IQR) | 1220 (2343) | 1061 (1814) | 1 | (1.00–1.00, p=0.403) | 1 | (1.00–1.00, p=0.419) |
| C reactive protein | Median (IQR) | 45 (100) | 77 (107) | 1 | (1.00–1.01, p<0.001)** | 1 | (1.00–1.01, p=0.021)* |
| Troponin | Median (IQR) | 20 (55) | 21 (46) | 1 | (1.00–1.00, p=0.890) | 1 | (1.00–1.00, p=0.667) |
| Albumin | Median (IQR) | 39 (7) | 37 (6) | 0.97 | (0.94–1.00, p=0.071) | 1.02 | (0.98–1.06, p=0.432) |
| Creatine kinase | Median (IQR) | 94 (131) | 145 (263) | 1 | (1.00–1.00, p=0.119) | 1 | (1.00–1.00, p=0.152) |
| Admitted from ED | Admitted (%) | 235 (75.2) | 453 (82.7) | – | – | ||
| Discharged (%) | 77 (24.8) | 95 (17.3) | 1.56 | (1.06–2.33, p=0.022)** | 1.35 | (0.79–2.30, p=0.272) | |
| Admitted to ITU from ED | No (%) | 307 (98.5) | 532 (97.1) | – | – | ||
| Yes (%) | 5 (1.5) | 16 (2.9) | 1.92 | (0.60–6.18, p=0.274) | 1.06 | (0.25–4.40, p=0.940) | |
| 30-day follow-up status | Discharged (%) | 259 (83.0) | 368 (67.1) | – | – | ||
| Admitted (%) | 22 (6.9) | 47 (8.5) | 1.53 | (0.82–2.87, p=0.181) | 1.64 | (0.77–3.51, p=0.198) | |
| Dead (%) | 31 (10.1) | 133 (24.4) | 3 | (1.86–4.84, p<0.001)** | 2.81 | (1.22–6.50, p=0.017)* | |
*p<0.05; **p<0.001.
ED, emergency department; ITU, intensive treatment unit; RT-PCR, reverse transcriptase PCR.