Table 4 Knowledge, attitude, Self-Efficacy, and practice of nail biting among study and control groups at pre- and post-intervention

Children’s Knowledge About Nail-Biting

Pretest

4.58 ± 1.84

4.75 ± 1.48

U=-1.07, P = 0.287

Posttest

8.57 ± 2.24

7.00 ± 1.56

U=-5.92, P = 0.006*

Significance

Z^Wil=6.496, P < 0.001**

Z^Wil= -5.622, P < 0.001**

Children’s Nail-Biting Practice/Habits

Pretest

50.60 ± 4.01

51.79 ± 3.98

U=-1.627, P = 0.104

Posttest

22.42 ± 5.69

42.76 ± 6.75

U = 0.104, P < 0.001**

Significance

Z^Wil=-7.119, P < 0.001*

Z^Wil=-6.54, P = 0.034*

Children’s Attitude Towards Nail-biting

Pretest

28.96 ± 3.29

28.69 ± 4.19

U=-0.102, P = 0.919

Posttest

16.84 ± 5.11

27.63 ± 4.57

U=-8.73, P < 0.001**

Significance

Z^Wil= -7.018, P < 0.001**

Z^Wil=-1.109, P = 0.267

Children’s Self-efficacy of Nail-biting

Pretest

7.82 ± 1.71

7.79 ± 1.59

U=-0.161, P = 0.872

Posttest

4.51 ± 1.43

7.13 ± 2.09

U=-6.94, P < 0.001**

Significance

Z^Wil= -6.533, P < 0.001**

Z^Wil=-1.82, P = 0.068