False positive compared with true negatives
| Population characteristic | Level | False positive (ambulance dispatched, not conveyed to hospital and no primary outcome 30 days) n=4230 | True negative (no ambulance dispatched and no primary outcome 30 days) n=1930 |
| Age (years) | Median (IQR) Mean | 66 (46–81) 62.9 | 37 (28–53) 41.6 |
| Sex (N, %) | Male | 1920 (45.4%) | 1000 (51.7%) |
| Comorbidity (N, %) | Cardiovascular disease | 235 (5.5%) | 30 (1.6%) |
| Chronic resp. disease | 1280 (30.3%) | 380 (19.5%) | |
| Diabetes | 600 (14.2%) | 155 (7.8% | |
| Hypertension | 1480 (35%) | 255 (13.1%) | |
| Immunosuppression (including steroid use) | 825 (19.5%) | 180 (9.4%) | |
| Active malignancy | 140 (3.3%) | 20 (0.9%) | |
| Obesity | 700 (16.5%) | 260 (13.4%) | |
| Pregnant | 50 (1.2%) | 40 (2.2%) | |
| Renal impairment | 110 (2.6%) | 15 (0.8%) | |
| Stroke | 90 (2.1%) | 15 (0.7%) | |
| Smoking status (N, %) | Smoker | 1570 (37.1%) | 640 (33.2%) |
| Number of drugs used (N, %) | 0 | 1040 (24.6%) | 955 (49.3%) |
| 1–5 | 2075 (49%) | 805 (41.7%) | |
| 6–10 | 970 (22.9%) | 150 (7.6%) | |
| 11 or more | 150 (3.5%) | 25 (1.4%) | |
| Clinical Frailty Scale (N, %) | Unknown | 1520 (35.9%) | 150 (7.6%) |
| Aged<65 | 2030 (48%) | 1735 (89.8%) | |
| 1–3 | 55 (1.3%) | * | |
| 3–6 | 245 (5.7%) | 25 (1.2%) | |
| 6–9 | 385 (9.1%) | 25 (1.2%) | |
| Ethnicity (N, %) | Asian or Asian British | 250 (5.9%) | 180 (9.2%) |
| Black or Black British | 60 (1.4%) | 50 (2.5%) | |
| Mixed | 35 (0.9%) | 30 (1.4%) | |
| Other Ethnic Groups | 50 (1.2%) | 65 (3.3%) | |
| White | 3080 (72.7%) | 1210 (62.7%) | |
| Unknown | 760 (17.9%) | 405 (20.9%) | |
| Deprivation Index (N, %) | Unknown | 420 (10%) | 130 (6.6%) |
| 1–2 | 1470 (38.6%) | 925 (51.3%) | |
| 3–4 | 720 (18.9%) | 320 (17.7%) | |
| 5–6 | 655 (17.2%) | 245 (13.5%) | |
| 7–8 | 560 (14.7%) | 190 (10.5%) | |
| 9–10 | 405 (10.6%) | 125 (6.9%) |
*Value suppressed due to small numbers.