Descriptive statistics and multilevel mixed effects linear regressions for smoking-related knowledge, attitudes, perceived norms and self-efficacy to refuse cigarette offers
| Baseline beginning of grade 5 | Follow-up mid of grade 7 | Change | Difference in change | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Intervention | Control | Intervention | Control | Intervention | Control | ||||
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Adjusted β* | 95% CI | p Value | |
| Knowledge† | 30.34 (19.47) | 30.11 (19.14) | 46.75 (21.59) | 37.74 (20.45) | 16.53 (26.46) | 7.53 (24.13) | 9.38 | 6.73 to 12.04 | <0.001 |
| Attitudes/risk perception‡ | 2.04 (0.51) | 2.04 (0.51) | 2.24 (0.51) | 2.16 (0.54) | 0.20 (0.61) | 0.12 (0.61) | 0.10 | 0.03 to 0.16 | 0.002 |
| Norms adult smoking§ | 6.08 (1.62) | 5.97 (1.59) | 6.04 (1.62) | 6.09 (1.55) | –0.03 (2.09) | 0.12 (1.95) | –0.08 | –0.24 to 0.07 | 0.265 |
| Norms peer smoking§ | 3.08 (2.64) | 2.93 (2.56) | 4.24 (2.28) | 4.02 (2.18) | 1.16 (3.10) | 1.10 (2.93) | 0.15 | –0.13 to 0.43 | 0.283 |
| Self-efficacy to refuse cigarettes¶ | 2.38 (1.04) | 2.36 (1.03) | 2.53 (0.80) | 2.49 (0.85) | 0.15 (1.20) | 0.11 (1.22) | 0.07 | –0.03 to 0.17 | 0.140 |
*Adjusted for age, gender, type of school, socioeconomic status, migration background, peer/parent/sibling smoking, sensation seeking, rebelliousness, earlier participation in a prevention programme, baseline value of the respective variable.
†Mean percentage of correct answers in a 7-item quiz.
‡Range 0–3, higher values representing more negative attitude.
§Range 0=nobody smokes to 10=everybody smokes.
¶Range 0–3, higher values representing higher self-efficacy.