Numbers of hospitals and effective questionnaires according to geographical region
| Region | No of hospitals | Hospital level | No of effective questionnaires | |
| 3A | Non-3A | |||
| Northeast China | 17 | 12 | 5 | 202 |
| East China | 54 | 35 | 19 | 647 |
| North China | 47 | 29 | 18 | 440 |
| Central China | 26 | 16 | 10 | 277 |
| South China | 30 | 18 | 12 | 269 |
| Southwest China | 26 | 17 | 9 | 231 |
| Northwest China | 20 | 12 | 8 | 188 |
| Total | 220 | 139 | 81 | 2254 |