Table 1.
Characteristics and selected outcomes of enrolled patients
| Derivation (n=21 743) | Validation (n=5922) | |
| Age in years, median (IQR) | 57 (38–73) | 56 (37–73) |
| Female (%) | 10 992 (50.5) | 3085 (52.1) |
| Arrival from, n (%) | ||
| Home | 19 879 (91.4) | 5429 (91.7) |
| Long-term care/rehabilitation facility/corrections facility | 1000 (4.6) | 262 (4.4) |
| No fixed address/shelter/single room occupancy | 574 (2.6) | 201 (3.4) |
| Interhospital transfer | 290 (1.3) | 30 (0.5) |
| Risk for infection, n (%) | ||
| Healthcare worker | 505 (2.3) | 567 (9.6) |
| Household/caregiver contact | 566 (2.6) | 161 (2.7) |
| Institutional exposure (eg, LTC, prison) | 1354 (6.2) | 213 (3.6) |
| Microbiology lab | 4 (0.0) | 8 (0.1) |
| Travel | 924 (4.2) | 344 (5.8) |
| Other | 1320 (6.1) | 449 (7.6) |
| Unknown | 5415 (24.9) | 1856 (31.3) |
| No documented risk for infection | 10 028 (46.1) | 1075 (18.1) |
| Arrival vital signs, median (IQR) | ||
| Body temperature | 36.7 (36.3–37.1) | 36.8 (36.5–37.1) |
| Heart rate | 91 (79–107) | 90 (78–105) |
| Oxygen saturation | 97 (95–98) | 97 (95–99) |
| Respiratory rate | 18 (18–20) | 18 (16–20) |
| Systolic blood pressure | 133 (118–150) | 136 (120–149) |
| Common comorbid conditions, n (%) | ||
| Active malignant neoplasm (cancer) | 1678 (7.7) | 333 (5.6) |
| Asthma | 1699 (7.8) | 468 (7.9) |
| Atrial fibrillation | 1598 (7.3) | 402 (6.8) |
| Chronic kidney disease | 1214 (5.6) | 321 (5.4) |
| Chronic lung disease (not asthma/pulmonary fibrosis) | 1729 (8) | 583 (9.8) |
| Chronic neurological disorder (not dementia; eg, stroke/TIA, seizure disorder) | 1310 (6) | 400 (6.8) |
| Congestive heart failure | 1450 (6.7) | 368 (6.2) |
| Coronary artery disease | 1591 (7.3) | 449 (7.6) |
| Dementia | 734 (3.4) | 188 (3.2) |
| Diabetes | 2583 (11.9) | 916 (15.5) |
| Dialysis | 198 (0.9) | 28 (0.5) |
| Dyslipidaemia | 2375 (10.9) | 543 (9.2) |
| Hypertension | 6320 (29.1) | 1697 (28.6) |
| Hypothyroidism | 1344 (6.2) | 397 (6.7) |
| Mild liver disease | 280 (1.3) | 90 (1.5) |
| Moderate/severe liver disease | 245 (1.1) | 88 (1.5) |
| Obesity (clinical impression) | 284 (1.3) | 108 (1.8) |
| Organ transplant | 128 (0.6) | 19 (0.3) |
| Rheumatological disorder | 1122 (5.2) | 258 (4.4) |
| Other | 10 075 (46.3) | 2174 (36.7) |
| Past malignant neoplasm (cancer) | 936 (4.3) | 256 (4.3) |
| Psychiatric condition/mental health diagnosis | 2967 (13.6) | 831 (14) |
| Pulmonary fibrosis | 80 (0.4) | 26 (0.4) |
| Symptoms reported, n (%) | ||
| Abdominal pain | 2725 (12.5) | 540 (9.1) |
| Altered consciousness/confusion | 1456 (6.7) | 322 (5.4) |
| Bleeding (haemorrhage) | 330 (1.5) | 22 (0.4) |
| Chest pain (includes discomfort or tightness) | 4242 (19.5) | 974 (16.4) |
| Chills | 2045 (9.4) | 594 (10) |
| Conjunctivitis | 49 (0.2) | 26 (0.4) |
| Cough | 7724 (35.5) | 2663 (44.9) |
| Diarrhoea | 2140 (9.8) | 526 (8.9) |
| Dizziness/vertigo | 1521 (7) | 300 (5.1) |
| Dysgeusia/anosmia | 140 (0.6) | 33 (0.6) |
| Ear pain | 144 (0.7) | 30 (0.5) |
| Fatigue/malaise | 3361 (15.5) | 924 (15.6) |
| Fever | 5055 (23.2) | 1580 (26.7) |
| Headache | 2144 (9.9) | 624 (10.5) |
| Hemoptysis (bloody sputum) | 298 (1.4) | 66 (1.1) |
| Joint pain (arthralgia) | 296 (1.4) | 82 (1.4) |
| Lower chest wall indrawing | 10 (0) | 7 (0.1) |
| Lymphadenopathy | 67 (0.3) | 21 (0.4) |
| Muscle aches (myalgia) | 1575 (7.2) | 517 (8.7) |
| Nausea/vomiting | 4219 (19.4) | 935 (15.8) |
| No recorded symptoms | 2113 (9.7) | 431 (7.3) |
| Runny nose (rhinorrhoea) | 1061 (4.9) | 501 (8.5) |
| Seizures | 205 (0.9) | 42 (0.7) |
| Shortness of breath (dyspnoea) | 8537 (39.3) | 2383 (40.2) |
| Skin rash | 241 (1.1) | 38 (0.6) |
| Skin ulcers | 27 (0.1) | <5 |
| Sore throat | 3024 (13.9) | 985 (16.6) |
| Sputum production | 1507 (6.9) | 401 (6.8) |
| Wheezing | 582 (2.7) | 130 (2.2) |
| Tobacco use, n (%) | 1852 (8.5) | 616 (10.4) |
| Illicit substance use, n (%) | 1219 (5.6) | 353 (6.0) |
| Oxygen required in ED, n (%) | 1919 (8.8) | 627 (10.6) |
| Hospital admission, n (%) | 9913 (45.6) | 2446 (41.3) |
| In-hospital death, n (%) | 753 (3.5) | 213 (3.6) |
| 7-day average incident COVID-19 cases, median (IQR) | 1.3 (0.73.2) | 0.96 (0.5–1.3) |
| SARS-CoV-2 positive, n (%) | 940 (4.3) | 227 (3.8) |
ED, emergency department; LTC, long-term care; TIA, transient ischaemic attack.