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. 2016 May 24;18(5):e103. doi: 10.2196/jmir.4643

Table 3.

Baseline values for participant demographic and substance use‒related variables by intervention condition (completers-only sample N=211).


Intervention Control Pa
Completers-only sample, nb (%) 108 (51.2) 103 (48.8)
Age in years, mean (SD) 16.87 (0.71) 17.03 (0.76) .130
Sex (women), % 52.9 52.6 .959
Country of residence, %

.955

Sweden 26.9 28.2

Germany 15.7 13.6

Belgium 13.0 11.7

Czech Republic 44.4 46.6
School status (yes) 88.0 88.3 .961
Parental education levelc, %

.198

Low 14.6 12.4

Middle 43.8 57.3

High 41.6 30.3
Intention to reduce alcohold, mean (SD) 2.76 (2.12) 3.13 (2.08) .223
Intention to abstain from illegal drugsd, mean (SD) 5.39 (2.37) 5.59 (2.22) .539
Descriptive peer drinking norms, mean (SD) 2.33 (0.66) 2.35 (0.64) .856
Substance use related risk (CRAFFT sumscore), mean (SD) 2.56 (1.32) 2.80 (1.35) .210
Age at first alcohol use, mean (SD) 12.97 (2.34) 13.06 (2.27) .781
Alcohol usee (last 12 months), mean (SD) 4.89 (2.27) 5.20 (2.47) .348
Alcohol usef (last 30 days), mean (SD) 5.35 (2.44) 5.53 (2.87) .644
Drinking frequencyg, mean (SD) 2.09 (0.79) 2.04 (0.89) .695
Drinking quantityg, mean (SD) 1.77 (1.27) 1.85 (1.46) .694
Binge drinking frequencyg, mean (SD) 1.54 (0.86) 1.69 (0.93) .261
Illegal drug use (last 30 days), % 42.6 39.5 .946
Polydrug use (last 30 days), % 37.0 31.1 .313

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 drinking index score, past 30 days (primary outcome).

gSeparate drinking indicators, scores ranging from 0-4 with higher scores indicating more severe drinking.