| Group | Number of cases | Occurrence time of thrombosis | Incidence rate of thrombosis | ||||
| 3 d | 3 - 7 d | 7 - 15 d | 15 - 30 d | >30 d | |||
| Experimental group | 120 | 0 | 1 | 1 | 1 | 0 | 2.5% |
| Control group | 120 | 0 | 4 | 3 | 3 | 2 | 10% |
| χ2 |
|
|
|
|
|
| 5.760 |
| P |
|
|
|
|
|
| 0.016 |