Characteristics of the respondents (n=2617)
| Characteristic | N | % |
| Age (years) | ||
| 20–30 | 587 | 22.4 |
| 31–40 | 1224 | 46.8 |
| 41–50 | 658 | 25.1 |
| 51+ | 119 | 4.5 |
| Missing value | 29 | 1.1 |
| Service years | ||
| 0–10 | 1088 | 41.6 |
| 11–20 | 720 | 27.5 |
| 30+ | 376 | 14.4 |
| Missing value | 433 | 16.5 |
| Hospital level | ||
| Tertiary hospitals | 1740 | 66.6 |
| Secondary hospital | 733 | 28.1 |
| Primary hospital | 139 | 5.3 |
| Missing value | 5 | 0.2 |
| Gender | ||
| Male | 1240 | 47.4 |
| Female | 1369 | 52.3 |
| Missing value | 8 | 0.3 |
| Education | ||
| College degree or below | 291 | 11.1 |
| Bachelor | 1350 | 51.7 |
| Master | 692 | 26.5 |
| Doctor | 277 | 10.6 |
| Missing value | 7 | 0.3 |
| Marital status | ||
| Unmarried | 397 | 15.2 |
| Married | 2148 | 82.1 |
| Divorced or loss of spouse | 70 | 2.7 |
| Missing value | 2 | 0.1 |
| Professional categories | ||
| Without professional title | 306 | 11.7 |
| Resident doctor | 564 | 21.6 |
| Attending physician | 898 | 34.3 |
| Associate chief physician | 569 | 21.7 |
| Chief physician | 270 | 10.3 |
| Missing value | 10 | 0.4 |
| Shift work | ||
| Often work during the day | 503 | 19.2 |
| Occasional work at night | 500 | 19.1 |
| Often work at night | 1613 | 61.6 |
| Missing value | 1 | 0.1 |
| Working time (hour) | ||
| 0–8 | 528 | 20.2 |
| 9–10 | 1297 | 49.6 |
| 11–12 | 504 | 19.2 |
| 13+ | 285 | 10.9 |
| Missing value | 3 | 0.1 |