Table 2 Socio-economic and demographic characteristics of study participants

Age (years, mean±SD)

17.17±0.72

17.20±0.74

17.14±0.70

1.81 ^a

Family income (%)

0.94 ^b

 Low (<1500)

15.9

15.2

16.4

 Medium (1500–2499)

33.3

33.2

33.6

 High (≥2500)

50.8

51.6

50.0

Family structure

7.73^b

 Single parent family

7.8

8.1

7.2

 Nuclear family

66.0

63.7

68.5

 Large family

26.2

28.1

24.2

Father’s education level (%)

10.83** ^b

 Middle school and below

7.6

8.5

6.9

 High school

45.6

42.4

48.7

 College and above

46.8

49.2

44.5

Mother’s education level (%)

7.08* ^b

 Middle school and below

9.4

9.3

9.6

 High school

50.8

48.4

53.1

 College and above

39.9

42.3

37.3