Table 1.

Characteristics of novice adolescent smokers, NDIT study, 1999–2005

Smokers at baseline, n (range) = 615–620Pooled sample of smokersa, n (range) = 3862–3921
 Male (%)b37.230.3
 Age, y [median (IQR)]13.4 (1.3)14.4 (1.7)
 French speaking (%)b19.423.3
 Single-parent family (%)b14.216.2
 Parent(s) university educated (%)b42.446.7
Psychosocial indicators
 Family stress [median (IQR)]1.2 (0.8)1.3 (0.6)
 Non–family-related stress [median (IQR)]1.6 (0.7)1.6 (0.8)
 Depression symptoms [median (IQR)]2.2 (1.1)2.2 (1.1)
 Impulsivity [median (IQR)]2.6 (1.3)2.6 (1.4)
 Novelty-seeking [median (IQR)]3.2 (1.1)3.2 (1.1)
 Self-esteem [median (IQR)]2.5 (0.7)2.4 (0.7)
 Worrying about weight (%)b47.849.3
 Cigarette package warnings make me afraid to smoke (% no)b43.940.6
 Cigarette ads make me want to smoke (% yes)b24.028.5
Overweight (%)25.528.7
Asthma (%)19.018.4
Lifestyle indicators
 Alcohol use (%)b74.680.3
 Use tobacco products other than cigarettes (%)b44.540.7
 Illicit drug use (%)b34.958.8
 Light physical activity [median (IQR)]6.3 (7.0)7.0 (6.0)
 Moderate physical activity [median (IQR)]10.0 (13.0)8.0 (13.0)
 Vigorous physical activity [median (IQR)]2.0 (7.0)2.0 (7.0)
 Participation in team sports (%)b56.249.3
 TV watching per week, h [median (IQR)]6.0 (5.5)5.5 (5.0)
Smoking and nicotine dependence indicators
 No. cycles since smoking initiation [median (IQR)]1.0 (1.0)4.0 (5.0)
 No. cigarettes smoked per month in past 3 months [median (IQR)]0.6 (5.1)3.0 (99.8)
 Tolerance (%)b21.030.2
 Other nicotine dependence symptoms [median (IQR)]2.0 (8.0)7.6 (13.0)
 Self-medication [median (IQR)]0.0 (2.4)1.0 (5.0)
 Withdrawal symptoms [median (IQR)]0.0 (1.1)1.0 (3.0)
Context-level indicators
Social environment
 Parent(s) smoke (%)b43.343.9
 Sibling(s) smoke (%)b29.934.2
 Friends smoke (%)b87.492.9
 Teachers/school staff smoke often (%)b77.880.0
Neighborhood indicators
 Tolerance of smoking at school (% high)b37.339.2
 Tolerance of smoking in local corner stores [median (IQR)]0.3 (0.2)0.4 (0.5)
 Tolerance of smoking in local restaurants [median (IQR)]0.3 (0.4)0.3 (0.4)
  • aIncludes up to 15 observations per participant.

  • bPercentages and medians were computed excluding missing data.