Table 2

Relationships between e-cigarette use at baseline (aged 13–14 years) and smoking cigarettes or any combustible tobacco 24 months later (aged 15–16 years) among those who were never smokers at baseline (n=3994)

Smoking at age 15–16 yearsBaseline e-cigarette use
NeverTriedInfrequentFrequent
(1–2 times)(1/month–1/week)(>1/week)
n (%) n (%) n (%) n (%)
Cigarette smoking
Never2743 (68.7)405 (10.1)30 (0.8)2 (0.1)
Once285 (7.2)147 (3.7)11 (0.3)1 (0.0)
Used to smoke89 (2.2)63 (1.6)8 (0.2)5 (0.1)
Rarely (<1/week)72 (1.8)44 (1.1)5 (0.1)1 (0.0)
Occasional (1–6/week)21 (0.5)18 (0.5)1 (0.0)0 (0.0)
Frequent (>6/week)25 (0.6)12 (0.3)6 (0.2)0 (0.0)
Any recent tobacco smoking
None3010 (75.4)556 (13.9)37 (0.9)4 (0.1)
One or more days226 (5.7)133 (3.3)23 (0.6)5 (0.1)