|  | Mean differencea (T2-T0: M ± SD or %) | Intervention* sexb (crude model) | Boysc |  | Girlsc | |||
---|---|---|---|---|---|---|---|---|---|
Outcome measure |  | Boys | Girls | β or RR (95 % CI) | P | β or RR (95 % CI) | P | β or RR (95 % CI) | P |
Smoking intentions | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Total non-smoking intentions | I | 0.10 ± 1.2 | 0.00 ± 0.7 | −0.01d (−0.21, 0.19) | 0.89 | n/a | - | n/a | - |
 | C | 0.06 ± 1.4 | 0.06 ± 0.9 |  |  |  |  |  |  |
Cigarette refusal self-efficacy | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Total refusal self-efficacy | I | 0.84 ± 3.4 | 0.27 ± 3.0 | −0.20d(−0.78, 0.39) | 0.51 | n/a | - | n/a | - |
 | C | 0.37 ± 3.8 | 0.53 ± 3.7 |  |  |  |  |  |  |
Attitudes towards smoking | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Smoking is bad for health (‘definitely yes’) | I | 8.3 | 2.5 | 1.02e (1.00, 1.04) | 0.17 | n/a | - | n/a | - |
 | C | 10.5 | 6.3 |  |  |  |  |  |  |
 Safe to smoke…year or two (‘definitely not’) | I | −0.5 | −0.9 | 0.94e (0.76, 1.17) | 0.64 | n/a | - | n/a | - |
 | C | −2.6 | 3.1 |  |  |  |  |  |  |
 Difficult to quit once started (‘definitely yes’) | I | 7.8 | 4.0 | 1.03e (0.81, 1.31) | 0.84 | n/a | - | n/a | - |
 | C | 6.2 | 7.1 |  |  |  |  |  |  |
 Others smoke harmful to you (‘definitely yes’) | I | 1.6 | −1.7 | 1.11e (0.77, 2.15) | 0.41 | n/a | - | n/a | - |
 | C | −0.9 | −3.2 |  |  |  |  |  |  |
 Affects sports performance (‘definitely yes’) | I | 25.1 | 21.3 | 1.05e (0.83, 1.32) | 0.73 | n/a | - | n/a | - |
 | C | 5.3 | −2.3 |  |  |  |  |  |  |
 Makes you gain or lose weight (‘no difference’) | I | −2.5 | −1.7 | 0.99e (0.26, 3.70) | 0.99 | n/a | - | n/a | - |
 | C | 1.8 | −8.7 |  |  |  |  |  |  |