Table 1.
Participant characteristics
| Variable | Healthcare workers | Community members | Total |
| Total population in Wuhan (1000) | 127.4 | 10 765.5 | 10 892.9 |
| COVID-19 cases in Wuhan | 2900 | 47 105 | 50 005 |
| Attack rate (per 1000) | 22.76 | 4.38 | 4.59 |
| Sample ratio, n (%) | 1138 (39.24) | 12 882 (27.35) | 14 020 (28.04) |
| By severity, n (%) | |||
| Asymptotic and mild | 513 (45.08) | 5876 (45.62) | 6389 (45.57) |
| Moderate | 455 (39.98) | 4603 (35.73) | 5058 (36.08) |
| Severe | 170 (14.94) | 2403 (18.65) | 2573 (18.35) |
| By district, n (%) | |||
| District 1 | 88 (7.73) | 1013 (7.86) | 1101 (7.85) |
| District 2 | 177 (15.55) | 2078 (16.13) | 2255 (16.08) |
| District 3 | 214 (18.80) | 3000 (23.29) | 3214 (22.92) |
| District 4 | 115 (10.11) | 1348 (10.46) | 1463 (10.44) |
| District 5 | 442 (38.84) | 3851 (29.89) | 4293 (30.62) |
| District 6 | 102 (8.96) | 1592 (12.36) | 1694 (12.08) |
| By sex, n (%) | |||
| Male | 380 (33.39) | 5994 (46.53) | 6374 (45.46) |
| Female | 758 (66.61) | 6888 (53.47) | 7646 (54.54) |
| By age, n (%) | |||
| <35 | 341 (29.96) | 1540 (11.96) | 1881 (13.42) |
| 35–49 | 443 (38.93) | 2963 (23.00) | 3406 (24.29) |
| >50 | 354 (31.10) | 8379 (65.04) | 8733 (62.29) |
| Mean (SD) | 39.60 (12.12) | 55.22 (15.71) | 53.96 (16.49) |
| Days, symptom to diagnosis | |||
| Median (IQR) | 9 (5–16) | 10 (5–16) | 10 (5–16) |
| Mean (SD) | 11.52 (8.69) | 12.50 (8.31) | 12.43 (8.34) |