Table 4.
Intervention effectsa on primary and (continuous) secondary outcomes (non-imputed datasetb).
| 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 usec | |||||||||||
|
|
Baseline | 5.43 (2.74) |
|
|
5.46 (2.81) |
|
|
|
|
|
|
|
|
3-months follow-up | 4.59 (2.77) | -0.85 (-1.49 to -0.26) | .009 | 5.35 (2.57) | 0.16 (-0.50 to 0.82) | .614 | 1.02 (0.25 to 1.79) | 6.80 (1, 134) | .010 | .26 |
| Drinking frequencyd | |||||||||||
|
|
Baseline | 2.01 (0.84) |
|
|
1.97 (.90) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.80 (0.84) | -0.36 (-0.55 to -0.16) | <.001 | 1.88 (0.81) | -0.11 (-0.31 to 0.10) | .305 | 0.25 (0.02 to 0.50) | 4.40 (1, 144) | .037 | .15 |
| Binge drinking frequencyd | |||||||||||
|
|
Baseline | 1.67 (0.92) |
|
|
1.78 (0.91) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.39 (0.95) | -0.11 (-0.36 to 0.14) | .375 | 1.66 (0.85) | 0.20 (-0.07 to 0.47) | .152 | 0.31 (0.01 to 0.61) | 4.20 (1, 121) | .044 | .16 |
| Drinking quantityd | |||||||||||
|
|
Baseline | 1.79 (1.45) |
|
|
1.84 (1.48) |
|
|
|
|
|
|
|
|
3-months follow-up | 1.59 (1.39) | -0.39 (-0.72 to -0.06) | .024 | 1.83 (1.36) | -0.16 (-0.50 to 0.17) | .336 | 0.23 (-0.17 to 0.62) | 1.30 (1, 155) | .257 | .13 |
| Illegal drug use frequencye | |||||||||||
|
|
Baseline | 0.87 (1.20) |
|
|
0.80 (1.14) |
|
|
|
|
|
|
|
|
3-months follow-up | 0.69 (1.10) | -0.13 (-0.37 to 0.11) | .292 | 0.71 (1.07) | -0.03 (-0.28 to 0.22) | .805 | 0.10 (-0.21 to 0.40) | 0.40 (1, 133) | .532 | .07 |
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.
bValid follow-up data for n=211 trial participants.
cAdapted AUDIT-C index score (primary outcome).
dAdapted AUDIT-C indicators, scores ranging from 0-4 with higher scores indicating more severe drinking.
eScores ranging from 0-4 with higher scores indicating more frequent illegal drug use.