Table 4 Effect of Zinc on children’s behavior problems (N = 1897)

  > 60 min

3.43 (1.33)

0.70–6.16

0.024

2.63 (0.31)

−0.71–5.97

0.180

4.04 (0.28)

1.17–6.91

0.016

 Male

–

–

–

–

–

–

–

–

–

 Female

−3.07 (1.21)

−8.26–2.12

0.035

−0.87 (0.54)

−2.32–0.58

0.894

−4.43 (0.38)

−6.07−− 2.78

0.017

 Yes

–

–

–

–

–

–

–

–

–

 No

−4.54 (1.47)

−6.04−−2.04

0.029

−3.63 (0.32)

−4.87−− 2.39

0.015

−1.63 (0.91)

−2.78−−0.58

0.175

 Rural

–

–

–

–

–

–

–

–

–

 Urban

−3.96 (0.61)

−6.58−−1.34

0.041

−2.55 (0.83)

−3.03−− 2.07

0.576

−4.05 (2.05)

−7.86−−0.24

0.046

 High school or higher

–

–

–

–

–

–

–

–

–

 Secondary

1.21 (1.83)

0.45–1.97

0.249

0.72 (0.53)

0.07–1.35

0.594

1.45 (0.37)

−0.05–2.95

0.160

 Primary school or lower

2.58 (0.95)

0.71–4.45

0.042

0.74 (0.54)

0.06–1.42

0.301

2.79 (0.59)

1.34–4.24

0.042

 Married

–

–

–

–

–

–

–

–

–

 Divorced

3.83 (1.08)

1.36–6.30

0.045

5.17 (2.13)

2.63–7.71

0.022

4.50 (1.26)

−1.63–10.63

0.025

 Widowed

3.09 (0.91)

−5.01–11.19

0.044

4.07 (1.14)

0.69–7.45

0.037

2.90 (0.46)

−0.99–6.79

0.091

  < 3000RMB

–

–

–

–

–

–

–

–

–

 3000-5000RMB

−3.49 (1.18)

−8.35−−1.37

0.046

0.33 (0.04)

−2.28−− 1.62

0.098

−0.66 (0.24)

−1.96–0.70

0.150

  > 5000RMB

− 2.61 (1.57)

−3.84−−1.38

0.032

−0.69 (0.47)

−1.18−− 0.20

0.346

− 1.22 (0.96)

−2.91–0.47

0.079

 Parents

–

–

–

–

–

–

–

–

–

 Grandparents

2.05 (1.37)

1.77–2.33

0.052

1.67 (0.85)

1.17–2.27

0.619

1.42 (0.34)

−2.90–4.32

0.054

 Nanny or others

4.41 (0.58)

2.37–6.05

0.021

3.27 (0.32)

1.89–4.66

0.019

2.66 (0.54)

0.40–5.08

0.037