The demographic characteristics distribution of the study participants
| Gender | Total n (%) | ||
|---|---|---|---|
| Male n (%) | Female n (%) | ||
| Age (year)* | |||
| ≤19 | 12 (1.1) | 43 (3.0) | 55 (2.2) |
| 20–39 | 887 (80.2) | 1259 (88.2) | 2146 (84.7) |
| ≥40 | 163 (14.7) | 102 (7.1) | 265 (10.5) |
| Missing | 44 (4.0) | 24 (1.7) | 68 (2.6) |
| Census register* | |||
| Shenzhen | 308 (27.9) | 270 (18.9) | 578 (22.8) |
| Outside Shenzhen | 781 (70.6) | 1142 (80.0) | 1923 (75.9) |
| Missing | 17 (1.5) | 16 (1.1) | 33 (1.3) |
| Education* | |||
| Primary school and below | 37 (3.3) | 99 (7.0) | 136 (5.4) |
| Middle school | 666 (60.2) | 1035 (72.4) | 1701 (67.1) |
| Bachelor degree or above | 362 (32.8) | 270 (18.9) | 632 (24.9) |
| Missing | 41 (3.7) | 24 (1.7) | 65 (2.6) |
| Monthly salary (¥)* | |||
| <2000 | 332 (30.0) | 803 (56.2) | 1135 (44.8) |
| 2000–4000 | 360 (32.5) | 363 (25.4) | 723 (28.5) |
| 4000–6000 | 206 (18.6) | 107 (7.5) | 313 (12.4) |
| >6000 | 172 (15.6) | 54 (3.8) | 226 (8.9) |
| Missing | 36 (3.3) | 101 (7.1) | 137 (5.4) |
| Marriage | |||
| Unmarried | 349 (31.6) | 427 (30.0) | 776 (30.7) |
| Married | 755 (68.3) | 987 (69.2) | 1742 (68.7) |
| Divorced or widowed | 2 (0.1) | 11 (0.6) | 13 (0.5) |
| Missing | 0 | 3 (0.2) | 3 (0.1) |
*The difference was statistically significant (p<0.05).