False negatives compared with true positives
| Population characteristic | Level | False negatives (no ambulance dispatch and primary outcome 30 days) n=70 | True positives (ambulance dispatch and primary outcome 30 days) n=1335 |
| Age (years) | Median (IQR) Mean | 61.5 (51–80) 64 | 80 (68–87) 76.7 |
| Sex (N, %) | Male | 35 (51.4%) | 760 (56.8%) |
| Comorbidity (N, %) | Cardiovascular disease | * | 115 (8.8%) |
| Chronic resp. disease | 15 (20%) | 400 (29.9%) | |
| Diabetes | 20 (25.7%) | 305 (23%) | |
| Hypertension | 25 (34.3%) | 685 (51.2%) | |
| Immunosuppression (including steroid use) | 10 (17.1%) | 350 (26.3%) | |
| Active malignancy | * | 160 (11.9%) | |
| Obesity | 10 (12.9%) | 95 (7%) | |
| Pregnant | * | * | |
| Renal impairment | * | 55 (4.2%) | |
| Stroke | * | 40 (3.2%) | |
| Social (N, %) | Smoker | 25 (32.9%) | 530 (39.6%) |
| Number of drugs used (N, %) | 0 | 20 (25.7%) | 155 (11.7%) |
| 1–5 | 30 (42.9%) | 670 (50.2%) | |
| 6–10 | 20 (28.6%) | 445 (33.3%) | |
| 11 or more | * | 65 (4.8%) | |
| Clinical Frailty Scale (N, %) | Unknown | 60 (84.3%) | 665 (49.8%) |
| Aged<65 | * | 260 (19.7%) | |
| 1–3 | * | 15 (1%) | |
| 3–6 | * | 80 (6.2%) | |
| 6–9 | * | 310 (23.4%) | |
| Ethnicity (N, %) | Asian or Asian British | * | 45 (3.5%) |
| Black or Black British | * | 15 (1%) | |
| Mixed | * | * | |
| Other Ethnic Groups | * | 10 (0.7%) | |
| White | 45 (61.4%) | 910 (68.1%) | |
| Unknown | 20 (28.6%) | 355 (26.5%) | |
| Deprivation Index (N, %) | Unknown | * | 185 (13.7%) |
| 1–2 | 30 (46%) | 410 (35.8%) | |
| 3–4 | 10 (17.4%) | 205 (17.9%) | |
| 5–6 | * | 210 (18.4%) | |
| 7–8 | 10 (17.4%) | 200 (17.2%) | |
| 9–10 | * | 120 (10.6%) | |
| Outcome (N, %) | Death | 45 (65.7%) | 1110 (83.3%) |
| Deaths due to COVID-19 (including after 30 days) | 20 (27.2%) | 520 (39%) | |
| Organ support (within 30 days) | 35 (47.1%) | 300 (22.6%) | |
| Hospitalisation (N, %) | ED attendance | 45 (65.7%) | 925 (69.2%) |
| Inpatient admission | 50 (72.9%) | 1035 (77.6%) | |
| Confirmed hospital diagnosis of COVID-19 (N, %)† | In ED or as inpatient at 30 days | 25 (34.3%) | 570 (42.7%) |
| Time to primary outcome from index contact- up to and including (N, %) | 72 hours | 25 (37.1%) | 445 (33.5%) |
| 7 days | 45 (62.8%) | 730 (54.9%) |
*Value suppressed due to small numbers.
†Unrestricted community testing for suspected COVID-19 infection was only available from 18 May 2020. Confirmed diagnosis is based on inpatient PCR testing or clinical diagnosis in hospital.
ED, emergency department.