Table 6.
Intervention effects on primary and (continuous) secondary outcomes (EM-imputed dataset).
| Outcomes after 3 months | WISEteens group (n=715) | Control group (n=734) | Between-group differences | ||||||||
| Mean (SD) | Change from baseline, adjusted mean (95% CI) | P | Mean (SD) | Change from baseline, adjusted mean (95% CI) | P | Adjusted mean (95% CI) | F(df) | P | d | ||
| Index alcohol useb | |||||||||||
|
|
Baseline | 5.24 (2.71) |
|
|
5.25 (2.78) |
|
|
|
|
|
|
|
|
3-months follow-up | 4.72 (1.58) | -0.63 (-0.73 to -0.52) | <.001 | 4.82 (1.52) | -0.49 (-0.60 to -0.39) | <.001 | 0.13 (0.02 to 0.25) | 5.23 (1, 1329) | .022 | .04 |
| Drinking frequencyc | |||||||||||
|
|
Baseline | 1.98 (0.81) |
|
|
1.93 (0.90) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.75 (0.47) | -0.24 (-0.27 to -0.20) | <.001 | 1.76 (0.46) | -0.20 (-0.24 to -0.17) | <.001 | 0.03 (-0.003 to -0.07) | 3.21 (1, 1329) | .073 | .11 |
| Binge drinking frequencyc | |||||||||||
|
|
Baseline | 1.54 (0.99) |
|
|
1.58 (1.02) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.39 (0.50) | -0.20 (-0.24 to -0.16) | <.001 | 1.42 (0.47) | -0.16 (-0.20 to -0.12) | <.001 | 0.03 (-0.01 to -0.08) | 2.30 (1, 1329) | .130 | .01 |
| Drinking quantityc | |||||||||||
|
|
Baseline | 1.74 (1.46) |
|
|
1.75 (1.49) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.64 (0.77) | -0.15 (-0.20 to -0.10) | <.001 | 1.71 (0.77) | -0.08 (-0.14 to -0.03) | .001 | 0.07 (0.01 to 0.12) | 5.33 (1, 1329) | .021 | .05 |
| Illegal drug use frequencyd | |||||||||||
|
|
Baseline | 0.84 (1.15) |
|
|
0.76 (1.08) |
|
|
|
|
|
|
|
|
3-months follow-up | 0.70 (0.76) | -0.12 (-0.15 to -0.08) | <.001 | 0.67 (0.71) | -0.11 (-0.14 to -0.08) | <.001 | 0.01 (-0.3 to 0.04) | 0.18 (1, 1329) | .670 | .04 |
aBased on linear mixed model with group as fixed factor, changes from baseline as outcomes, and baseline scores, country, and parental educational attainment as covariates for continuous outcomes. Cohen’s d calculated by subtracting the average difference score between pretest and posttest of the control group from the corresponding difference score of the intervention group and dividing the result by the pooled standard deviation of the baseline scores.
bAdapted AUDIT-C index score (primary outcome).
cAdapted AUDIT-C indicators, scores ranging from 0-4 with higher scores indicating more severe drinking.
dScores ranging from 0-4 with higher scores indicating more frequent illegal drug use.