Table 1.
Baseline characteristics of COVID-19 patients and matched controls in Hong Kong.
| Baseline characteristics | Controls (N = 3,168,467) | COVID-19 patients (N = 1,028,721) | SMD | Controls (N = 3,168,467) | COVID-19 patients (N = 3,168,131) | SMD |
|---|---|---|---|---|---|---|
| Age, years | 54.09 (18.08) | 52.68 (18.12) | 0.077 | 54.09 (18.08) | 54.25 (18.33) | 0.009 |
| Sex | 0.014 | 0.003 | ||||
| Male | 1,391,897 (43.9) | 458,872 (44.6) | 1,391,897 (43.9) | 1,395,733 (44.1) | ||
| Female | 1,776,570 (56.1) | 569,849 (55.4) | 1,776,570 (56.1) | 1,772,398 (55.9) | ||
| Charlson Comorbidity Index | 0.31 (0.84) | 0.34 (0.93) | 0.040 | 0.31 (0.84) | 0.32 (0.84) | 0.015 |
| Pre-existing comorbidities | ||||||
| Myocardial infarction | 20,735 (0.7) | 7938 (0.8) | 0.014 | 20,735 (0.7) | 24,840 (0.8) | 0.015 |
| Congestive Heart Failure | 27,066 (0.9) | 11,959 (1.2) | 0.031 | 27,066 (0.9) | 39,530 (1.2) | 0.039 |
| Peripheral vascular disease | 7702 (0.2) | 2804 (0.3) | 0.006 | 7702 (0.2) | 8777 (0.3) | 0.007 |
| Cerebrovascular disease | 107,212 (3.4) | 37,577 (3.7) | 0.015 | 107,212 (3.4) | 121,227 (3.8) | 0.024 |
| Chronic obstructive pulmonary disease | 56,414 (1.8) | 22,388 (2.2) | 0.028 | 56,414 (1.8) | 69,173 (2.2) | 0.029 |
| Dementia | 8719 (0.3) | 4983 (0.5) | 0.034 | 8719 (0.3) | 17,918 (0.6) | 0.045 |
| Paralysis | 6257 (0.2) | 2336 (0.2) | 0.006 | 6257 (0.2) | 7217 (0.2) | 0.007 |
| Chronic renal failure | 33,670 (1.1) | 13,672 (1.3) | 0.025 | 33,670 (1.1) | 39,118 (1.2) | 0.016 |
| Mild liver disease | 4049 (0.1) | 1531 (0.1) | 0.006 | 4049 (0.1) | 4271 (0.1) | 0.002 |
| Moderate-severe liver disease | 2644 (0.1) | 1073 (0.1) | 0.007 | 2644 (0.1) | 2674 (0.1) | <0.001 |
| Ulcers | 29,593 (0.9) | 10,640 (1.0) | 0.010 | 29,593 (0.9) | 31,796 (1.0) | 0.007 |
| Inflammatory polyarthropathies other than rheumatoid arthritis | 276 (0.0) | 99 (0.0) | 0.001 | 276 (0.0) | 305 (0.0) | 0.001 |
| Acquired Immune Deficiency Syndrome | 4 (0.0) | 0 (0.0) | 0.002 | 4.0 (0.0) | 0.0 (0.0) | 0.002 |
| Malignancy | 87,658 (2.8) | 31,196 (3.0) | 0.016 | 87,658 (2.8) | 82,897 (2.6) | 0.009 |
| Metastatic solid tumour | 13,071 (0.4) | 5284 (0.5) | 0.015 | 13,071 (0.4) | 9483.4 (0.3) | 0.019 |
| Diabetes without chronic complication | 345,420 (10.9) | 114,733 (11.2) | 0.008 | 345,420 (10.9) | 348,693 (11.0) | 0.003 |
| Diabetes with chronic complication | 22,405 (0.7) | 8213 (0.8) | 0.011 | 22,405 (0.7) | 22,979 (0.7) | 0.002 |
| Doses of COVID-19 vaccines received | 0.154 | 0.002 | ||||
| 0 | 478,424 (15.1) | 105,195 (10.2) | 478,424 (15.1) | 480,183 (15.2) | ||
| 1 | 209,584 (6.6) | 81,059 (7.9) | 209,584 (6.6) | 209,879 (6.6) | ||
| 2 | 1,028,818 (32.5) | 363,420 (35.3) | 1,028,818 (32.5) | 1,028,472 (32.5) | ||
| 3/4 | 1,451,641 (45.8) | 479,047 (46.6) | 1,451,641 (45.8) | 1,449,597 (45.8) |
SMD: Standard mean difference.