Table 4 Multilevel analyses exploring interaction effects by sex between baseline (T0) and post-intervention (T1)

Smoking intentions

 Total non-smoking intentions

I

0.10 ± 1.2

−0.04 ± 0.7

0.10^d (−0.10, 0.30)

0.32

n/a

−

n/a

-

C

0.16 ± 1.0

0.00 ± 0.9

Cigarette refusal self-efficacy

 Total refusal self-efficacy

I

0.32 ± 3.9

0.25 ± 3.2

0.87^d (0.09, 1.64)

0.03*

−0.18^d (−0.77, 0.41)

0.54

0.72^d (0.21, 1.23)

<0.01*

C

0.39 ± 3.6

−0.07 ± 3.8

Attitudes towards smoking

 Smoking is bad for health (‘definitely yes’)

I

5.5

2.0

1.05^e (1.00, 1.11)

0.12

n/a

-

n/a

-

C

4.4

0.8

 Safe to smoke…year or two (‘definitely not’)

I

0.9

5.3

1.16^e (0.95, 1.42)

0.23

n/a

-

n/a

-

C

−4.4

−5.6

 Difficult to quit once started (‘definitely yes’)

I

17.4

13.5

1.19^e (0.90, 1.57)

0.30

n/a

-

n/a

-

C

2.6

−3.1

 Others smoke harmful to you (‘definitely yes’)

I

3.3

1.4

1.14^e (0.84, 2.23)

0.29

n/a

-

n/a

-

C

−0.9

−4.0

 Affects sports performance (‘definitely yes’)

I

30.3

30.3

1.16^e (0.90, 1.50)

0.34

n/a

-

n/a

-

C

5.3

−3.1

 Makes you gain or lose weight (‘no difference’)

I

23.4

29.1

1.21^e (0.79, 2.31)

0.36

n/a

-

n/a

-

C

−2.6

−15.0