Baseline characteristics of dataset stratified by overall SARS-CoV-2 RT-PCR status, including subsequent swabs during the study period
| SARS-CoV-2 RT-PCR | P value | Missing (%) | ||
| Negative | Positive | |||
| n (%) | 435 (36.3) | 763 (63.7) | ||
| No of swabs (%) | 810 (48.3) | 868 (51.7) | ||
| Age (mean (SD)) | 62.74 (17.72) | 66.18 (17.58) | 0.001* | 0 |
| Ethnicity | 0.097 | 19 | ||
| Other Asian (%) | 29 (8.0) | 72 (11.8) | ||
| South Asian (%) | 27 (7.5) | 38 (6.2) | ||
| Black (%) | 41 (11.4) | 91 (14.9) | ||
| Mixed (%) | 6 (1.7) | 6 (1.0) | ||
| Other (%) | 56 (15.5) | 105 (17.2) | ||
| White (%) | 202 (56.0) | 297 (48.8) | ||
| Sex—Male (%) | 233 (53.6) | 480 (62.9) | 0.002* | 0 |
| Oxygen saturation (median (IQR)) | 95 (6) | 93 (8) | <0.001** | 6.3 |
| Respiratory rate (median (IQR)) | 22 (8) | 26 (12) | <0.001** | 6.3 |
| Glasgow Coma Scale (median (IQR)) | 15 (0) | 15 (0) | 0.043* | 6.6 |
| Systolic BP (median (IQR)) | 134 (32) | 130 (30) | 0.009* | 15.8 |
| Heart rate (median (IQR)) | 96 (27) | 94 (27) | 0.092 | 6.4 |
| Temperature (median (IQR)) | 37.1 (1.4) | 37.7 (1.4) | <0.001** | 6.7 |
| Chest X-ray report | <0.001** | 0 | ||
| Alternative pathology (%) | 4 (0.9) | 3 (0.4) | ||
| No abnormalities (%) | 178 (4.9) | 136 (17.8) | ||
| Indeterminate (%) | 83 (19.1) | 169 (22.1) | ||
| Classic COVID-19 (%) | 170 (39.1) | 455 (59.6) | ||
| Presence of comorbidities (%) | 297 (79.0) | 482 (80.3) | 0.669 | 18.5 |
| Dyspnoea (%) | 274 (69.4) | 497 (75.5) | 0.034 | 12.1 |
| Neutrophils (median (IQR)) | 6.42 (4.56) | 5.25 (3.92) | <0.001** | 2.3 |
| D-dimer (median (IQR)) | 1250 (2440) | 1105 (1803) | 0.204 | 23.2 |
| Albumin (median (IQR)) | 39 (7) | 37 (6) | <0.001** | 10 |
| C reactive protein (median (IQR)) | 91.0 (115) | 146.5 (264.8) | <0.001** | 3 |
| Creatine kinase (median (IQR)) | 51 (104) | 145 (260) | <0.001** | 23.3 |
| Troponin (median (IQR)) | 19 (46) | 20 (44) | 0.278 | 19.1 |
| Admitted (%) | 331 (76.0) | 635 (83.2) | 0.003* | 0.1 |
| Admitted to ITU (%) | 5 (1.3) | 32 (4.8) | 0.005* | 12.4 |
| 30-day follow-up status | <0.001** | 24 | ||
| Discharged (%) | 219 (78.2) | 367 (58.3) | ||
| On ambulatory follow-up (%) | 14 (5.0) | 49 (7.8) | ||
| Admitted (%) | 18 (6.4) | 60 (9.5) | ||
| Died (%) | 29 (10.4) | 154 (24.4) | ||
| CT report | <0.001** | 0 | ||
| No pathology identified (%) | 23 (22.1) | 6 (3.3) | ||
| Classic COVID-19 findings (%) | 52 (50.0) | 157 (85.8) | ||
| Indeterminate for COVID-19 (%) | 14 (13.5) | 14 (7.7) | ||
| Alternative pathology identified (%) | 15 (14.4) | 6 (3.3) | ||
| Day of symptoms (mean (SD)) | 9.84 (9.63) | 8.56 (15.80) | 0.368 | 69.2 |
There were 480 additional swabs on 399 unique patients with a median of 2 and mean of 3.5 per patient.
*Significant at p<0.05; **significant at p<0.001.
BP, blood pressure; RT-PCR, reverse transcriptase PCR.