Table 1

Characteristics of participants in the Nicotine Dependence in Teens Study (1999–2011) by Alcohol Frequency Trajectory Group

Alcohol Frequency Trajectory GroupP value*
Late triers (n=197)Decreasers (n=123)Late escalators (n=135)Early slow escalators (n=213)Steady drinkers (n=186)Early rapid escalators (n=204)Early frequent drinkers (n=235)
Male (%)58.466.750.437.150.533.850.6<0.0001
Age (years, mean (SD))12.7 (0.5)12.8 (0.5)12.7 (0.4)12.7 (0.4)12.7 (0.5)12.7 (0.6)12.9 (0.7)<0.0001
Mother university-educated (%)35.342.250.942.849.743.747.40.175
Single-parent family (%)10.49.010.68.29.97.210.90.860
French spoken at home (%)23.838.535.634.621.434.730.90.003
Used alcohol at baseline (%)2.159.020.812.073.740.088.6<0.0001
Parents smoke (%)30.143.729.037.036.742.849.30.000
Friends smoke (%)16.132.015.926.042.940.870.0<0.0001
Depressive symptoms (mean (SD))2.0 (0.6)2.1 (0.7)2.0 (0.6)2.0 (0.5)2.2 (0.6)2.1 (0.6)2.3 (0.7)<0.0001
Impulsivity (median (IQR))1.8 (0.9)2.0 (1.4)2.0 (1.1)2.1 (1.3)2.2 (1.3)2.4 (1.4)2.6 (1.6)<0.0001
Novelty-seeking (mean (SD))2.5 (0.8)2.9 (0.9)2.8 (0.8)2.9 (0.8)2.9 (0.9)3.1 (0.8)3.1 (0.9)<0.0001
  • *Categorical variables (%) were compared using Χ2 tests. For continuous variables, analysis of variance was used to compare those with normal distributions (mean (SD)) and Kruskall-Wallis tests were used for non-normally distributed variables (median (IQR)).