Pre-intervention | Post-intervention | ||||||||
Group | Number of cases | Class I | Class II | Class III | Grade IV | Class I | Class II | Class III | Grade IV |
Control group | 30 | 4 (13) | 14 (47) | 8 (27) | 4 (13) | 11 (37) | 12 (40) | 5 (17) | 2 (6) |
Observation group | 30 | 3 (10) | 15 (50) | 9 (30) | 3 (10) | 17 (57) | 13 (43) | 0 (0) | 0 (0) |
Z value | 0.382 | 2.218 | |||||||
P value | 0.612 | 0.028 |