Table 2.
Baseline values for participant demographic and substance use‒related variables by intervention condition (randomized sample N=1449).
|
|
Intervention | Control | Pa | |
| Randomized sample, nb (%) | 715 (49.3) | 734 (50.6) |
|
|
| Age in years, mean (SD) | 16.81 (0.75) | 16.85 (0.74) | .253 | |
| Sex (women), % | 47.8 | 48.6 | .758 | |
| Country of residence, % |
|
|
.574 | |
|
|
Sweden | 16.2 | 18.4 |
|
|
|
Germany | 10.9 | 9.3 |
|
|
|
Belgium | 9.8 | 9.9 |
|
|
|
Czech Republic | 63.3 | 62.4 |
|
| School status (yes), % | 95.0 | 94.8 | .885 | |
| Parental education levelc, % |
|
|
.060 | |
|
|
Low | 10.1 | 10.9 |
|
|
|
Middle | 61.4 | 66.3 |
|
|
|
High | 28.5 | 22.9 |
|
| Intention to reduce alcohold, mean (SD) | 3.04 (2.30) | 3.22 (2.31) | .136 | |
| Intention to abstain from illegal drugsd, mean (SD) | 5.31 (2.46) | 5.40 (2.40) | .501 | |
| Descriptive peer drinking norms, mean (SD) | 2.31 (0.79) | 2.32 (0.78) | .714 | |
| Substance use related risk (CRAFFT sum score), mean (SD) | 2.75 (1.42) | 2.72 (1.35) | .608 | |
| Age at first alcohol use, mean (SD) | 12.92 (2.30) | 13.00 (2.20) | .497 | |
| Alcohol usee (last 12 months), mean (SD) | 4.91 (2.49) | 5.10 (2.58) | .167 | |
| Alcohol usef (last 30 days), mean (SD) | 5.43 (2.74) | 5.46 (2.82) | .803 | |
| Drinking frequencyg, mean (SD) | 2.01 (0.84) | 1.97 (0.89) | .413 | |
| Drinking quantityg, mean (SD) | 1.79 (1.45) | 1.84 (1.48) | .586 | |
| Binge drinking frequencyg, mean (SD) | 1.67 (0.92) | 1.78 (0.91) | .048 | |
| Illegal drug use (last 30 days), % | 45.0 | 43.0 | .460 | |
| Polydrug use (last 30 days), % | 49.2 | 40.1 | .734 | |
aResults of chi-square tests for categorical and ttests for continuous measures.
bMay differ for individual variables due to single missing values.
cFather’s highest educational attainment.
dScores ranging from 1-7 with higher scores indicating higher motivation for change.
eAUDIT-C index score, past 12 months.
fAUDIT-C based index score, past 30 days (primary outcome).
gSeparate drinking indicators, scores ranging from 0-4 with higher scores indicating more severe drinking.