Table 1 Demographic characteristics and chi-square test results for 2,816 participant students

Sex

12.702

<0.001

 Boys

1382

178 (216)

12.9 (15.6)

 Girls

1434

125 (149)

8.7 (10.4)

Grade

12.617

0.006

 1–3

737

61 (67)

8.3 (9.1)

 4–6

723

81 (100)

11.2 (13.8)

 7–9

691

96 (117)

13.9 (16.9)

 10–12

665

65 (81)

9.8 (12.2)

Residence

8.854

0.012

 Urban

939

78 (90)

8.3 (9.6)

 Suburban

918

109 (138)

11.9 (15.0)

 Exurban

959

116 (137)

12.1 (14.3)

BMI

0.005

0.942

 <24

2448

263 (316)

10.7 (12.9)

 ≥24

368

40 (49)

10.9 (13.3)

Personality

14.314

0.001

 Introversive

282

17 (18)

6.0(6.4)

 Intermediate

1543

154 (153)

10.0(9.9)

 Extroversive

991

132 (194)

13.3(19.6)

Number of sibling

7.011

0.008

 0

1631

154 (182)

9.4(11.2)

 ≥1

1185

149(183)

12.6(15.4)

Health Status

13.453

0.001

 Good

2144

211(253)

9.8(11.8)

 Fair

637

83(100)

13.0(15.7)

 Poor

35

17(12)

25.7(34.3)

Number of people living together

9.772

0.008

 ≤3

1142

117(143)

10.2(12.5)

 4–6

1613

172(204)

10.7(12.6)

 ≥7

61

14(18)

23.0(29.5)

Father’s educational level

6.110

0.047

 ≤ grade 6

402

51 (61)

12.7(15.2)

 grade 7–12

1563

179(219)

11.5(14.0)

 > grade 12

831

72 (84)

8.7(10.1)

 Missing

20

1 (1)

---

Mather’s educational level

8.404

0.015

 ≤ grade 6

824

109(140)

13.2(17.0)

 grade 7–12

1402

144(153)

10.3(10.9)

 > grade 12

582

50(72)

8.6(12.4)

 Missing

8

0

---

Father’s Occupation

10.839

0.028

 Farmer

175

16(21)

9.1(12.0)

 Manual labor

592

83(101)

14.0(17.6)

 White collar

999

94(110)

9.4(11.0)

 Individual merchant

636

74(89)

11.6(14.0)

 Others

394

35(43)

8.9(10.9)

 Missing

20

1(1)

---

Mother’s Occupation

10.581

0.032

 Farmer

138

12(16)

8.7(11.6)

 Manual labor

561

76(87)

13.5(15.5)

 White collar

876

77(92)

8.8(10.5)

 Individual merchant

440

56(63)

12.7(14.3)

 Others

793

82(107)

10.3(13.5)

 Missing

8

0

Parents’ marital status

9.499

0.002

 Married

2697

280(341)

10.4(12.6)

 Non-married

119

23(24)

19.3(20.2)

Household income*

4.390

0.111

 <2000

855

91 (107)

10.6(12.5)

 2000–3999

920

91 (106)

9.9(11.5)

 ≥4000

719

94 (117)

13.1(16.3)

 Missing

322

27 (35)

---

Total

2861

303 (365)

10.6(12.8)