| 组别 | n | 优 | 良 | 可 | 差 | 优良率(%) |
| PFNA组 | 53 | 28 (52.83) | 19 (35.85) | 4 (7.55) | 2 (3.77) | 36 (88.68) |
| DHS组 | 45 | 17 (42.22) | 12 (31.11) | 12 (17.78) | 4 (8.89) | 28 (73.33) |
| x2 |
|
|
|
|
| 8.339 |
| P |
|
|
|
|
| 0.040 |