Table 2 Smoking prevalence among family members and prevalence of students who have no friend, as reported by students, and the odds ratio and population attributable risk of a student's current smoking with smoking by a family member

55.2 ± 0.3

52.6 ± 0.4

46.2 ± 0.4

1.30

1.19–1.42

1.39

1.27–1.52

1.54

1.33–1.74

14.2

17.0

20.0

13.5 ± 0.3

16.1 ± 0.3

16.9 ± 0.3

1.62

1.45–1.81

1.91

1.72–2.11

2.20

1.91–2.54

7.7

12.8

16.9

11.6 ± 0.2

10.8 ± 0.2

7.9 ± 0.1

2.72

2.45–3.02

2.80

2.52–3.11

2.90

2.47–3.40

16.6

16.3

13.1

4.5 ± 0.1

4.5 ± 0.1

3.8 ± 0.1

2.85

2.45–3.32

3.03

2.62–3.49

2.69

2.19–3.31

7.7

8.4

6.0

3.9 ± 0.1

4.1 ± 0.1

6.5 ± 0.1

0.89

0.71–1.11

0.79

0.63–1.00

0.88

0.68–1.14

−0.4

−0.9

−0.8

54.7 ± 0.4

53.1 ± 0.4

43.8 ± 0.3

1.33

1.27–1.40

1.38

1.31–1.46

1.70

1.60–1.80

15.3

16.8

23.5

14.6 ± 0.5

15.6 ± 0.4

14.5 ± 0.3

1.77

1.67–1.89

1.76

1.64–1.88

2.01

1.87–2.17

10.1

10.6

12.8

19.0 ± 0.4

17.3 ± 0.3

13.9 ± 0.2

2.16

2.05–2.28

2.11

1.98–2.25

2.36

2.20–2.53

18.1

16.1

15.9

7.7 ± 0.2

8.0 ± 0.2

6.3 ± 0.2

2.31

2.13–2.51

2.46

2.25–2.69

2.59

2.36–3.25

9.2

10.5

9.1

3.5 ± 0.1

3.5 ± 0.1

6.7 ± 0.1

0.43

0.37–0.49

0.31

0.26–0.38

0.36

0.31–0.43

−2.0

−2.5

−4.5

56.1 ± 0.3

55.4 ± 0.2

48.9 ± 0.3

1.17

1.02–1.34

1.30

1.14–1.47

1.17

0.99–1.80

8.7

14.3

7.7

14.6 ± 0.3

18.0 ± 0.3

15.4 ± 0.3

2.18

1.88–2.52

2.54

2.24–2.89

3.20

1.87–2.17

14.7

21.7

25.3

11.7 ± 0.2

11.9 ± 0.1

8.7 ± 0.1

2.44

2.10–2.83

2.76

2.41–3.17

2.59

2.20–2.53

14.4

17.3

12.2

5.1 ± 0.1

5.5 ± 0.1

4.7 ± 0.1

3.56

2.98–4.25

3.43

2.91–4.04

3.31

2.36–2.86

11.5

11.8

9.8

2.6 ± 0.1

2.8 ± 0.0

4.0 ± 0.1

1.81

1.33–2.44

0.70

0.47–1.05

0.85

0.56–1.28

2.1

−0.8

−0.6

54.5 ± 0.3

53.9 ± 0.3

45.7 ± 0.4

1.23

1.15–1.31

1.38

1.28–1.48

1.49

1.36–1.63

11.1

17.0

18.3

14.0 ± 0.3

15.9 ± 0.3

16.3 ± 0.4

2.22

2.06–2.39

2.24

2.07–2.43

2.59

2.35–2.86

14.6

16.5

20.6

18.6 ± 0.3

17.8 ± 0.2

14.4 ± 0.3

1.75

1.63–1.88

1.76

1.62–1.91

1.88

1.70–2.09

12.2

11.9

11.2

8.5 ± 0.2

8.8 ± 0.2

6.7 ± 0.2

3.02

2.77–3.29

2.80

2.54–3.07

2.87

2.54–3.25

14.7

13.7

11.1

2.3 ± 0.0

2.5 ± 0.0

4.1 ± 0.1

0.57

0.44–0.73

0.31

0.22–0.45

0.44

0.32–0.60

−1.0

−1.8

−2.3