Baselines characteristics of people with COVID-19 within the CHIA database cohort, stratified by incidence of the study outcomes (hospitalisation or all-cause mortality)
| Characteristics | Hospitalisation or all-cause mortality | |
| Yes | No | |
| N | 2750 | 4171 |
| Received seasonal influenza vaccination, n (%) | 1166 (42.4) | 1447 (34.7) |
| Age baseline; mean (SD) | 62.7 (22.8) | 45.5 (23.1) |
| Female, n (%) | 1540 (56.0) | 2580 (61.9) |
| Ethnicity, n (%) | ||
| Asian | 106 (3.9) | 222 (5.3) |
| Black | 17 (0.6) | 37 (0.9) |
| Missing data | 1174 (42.7) | 1099 (26.3) |
| Mixed or other | 23 (0.8) | 78 (1.9) |
| White | 1430 (52.0) | 2735 (65.6) |
| Socioeconomic status (IMD), n (%) | ||
| 1 (most deprived) | 280 (10.2) | 337 (8.1) |
| 2 | 479 (17.4) | 576 (13.8) |
| 3 | 539 (19.6) | 668 (16.0) |
| 4 | 611 (22.2) | 975 (23.4) |
| 5 (least deprived) | 789 (28.7) | 1479 (35.5) |
| Missing | 52 (1.9) | 136 (3.3) |
| Frailty score, mean (SD) | 0.2 (0.2) | 0.1 (0.2) |
| Frailty score, median (IQR) | 0.2 (0.1–0.3) | 0.1 (0.0–0.2) |
| Comorbidities, n (%) | ||
| Hypertension | 586 (21.3) | 810 (19.4) |
| Stroke | 154 (5.6) | 142 (3.4) |
| Asthma | 306 (11.1) | 660 (15.8) |
| Chronic obstructive pulmonary disease | 157 (5.7) | 177 (4.2) |
| Coronary heart disease | 176 (6.4) | 192 (4.6) |
| Heart failure | 115 (4.2) | 81 (1.9) |
| Type 1 diabetes | 15 (0.5) | 27 (0.6) |
| Type 2 diabetes | 256 (9.3) | 303 (7.3) |
| CKD stage 3–5 | 173 (6.3) | 178 (4.3) |
| Smoking status, n (%) | ||
| Current smoker | 291 (10.6) | 493 (11.8) |
| Ex-smoker | 1027 (37.3) | 1144 (27.4) |
| Never smoked | 1292 (47.0) | 1987 (47.6) |
| Missing data | 140 (5.1) | 547 (13.1) |
| Body mass index | 28.0 (7.0) | 27.8 (6.8) |
| Medication, n (%) | ||
| Antiplatelets | 561 (20.4) | 332 (8.0) |
| Oral anticoagulants | 437 (15.9) | 214 (5.1) |
| ACE inhibitors | 539 (19.6) | 438 (10.5) |
| ARB | 236 (8.6) | 237 (5.7) |
| Diuretics | 681 (24.8) | 370 (8.9) |
| Calcium channel blockers | 547 (19.9) | 410 (9.8) |
| Beta blockers | 656 (23.9) | 461 (11.1) |
| Alpha blockers | 87 (3.2) | 54 (1.3) |
| Insulin | 179 (6.5) | 91 (2.2) |
| Diabetic oral agents | 363 (13.2) | 248 (5.9) |
| Lipid-lowering drugs including statins | 894 (32.5) | 656 (15.7) |
CHIA, Care and Health Information Analytics; CKD, chronic kidney disease; IMD, Index of Multiple Deprivation.