Table 1 Characteristics of adolescent school children at baseline

Mean age (SD)

9.6(0.9)

9.55(0.8)

9.7(1.0)

 < 0.001

Age categories

 8–9 years old

395(40.2)

254(50.5)

141(29.6)

 9–10 years old

534(54.4)

243(48.3)

291(61.1)

 10–11 years old

50(5.1)

6(1.2)

44(9.2)

 < 0.001

Gender

 Boys

496(50.5)

258(51.1)

238(49.9)

 Girls

486(49.5)

247(48.9)

239(50.1)

0.7

Class

 Class II

416(42.4)

257(50.9)

159(33.3)

 Class III

415(42.3)

248(49.1)

167(35)

 Class IV

151(15.4)

-

151(32)

-

Parents employment status^a

 Only father

733(74.6)

390(77)

343(72.1)

 Both mother and father

226(23)

100(19.9)

126(26.5)

 Only mother

16(1.6)

11(2.2)

5(1.1)

 None of the parent

3(0.3)

1(0.2)

2(0.4)

-