When using any SRB (no/yes) as the binary variable, there was a sex interaction (Likelihood-ratio test LR chi2 (2) = 7.08; p=.029), so that the association of early onset regular tobacco use was significant among females only. When adjusted for school achievement, age, depression, impulsivity and alcohol dependence symptoms, as well as for parental education, those females who started regular tobacco use at an age younger than 14 had a significantly higher likelihood for any SRB (AOR 3.97, 95%CI 1.73–9.13, p=.001). However, as seen in Table 2, those who started tobacco use between ages of 14 and 22 also had an elevated risk compared to never users (AOR 1.92, 95%CI 1.27–2.92, p=.002). Considering baseline smoking status, daily smokers had over two-fold likelihood for any SRB compared to never smokers (AOR 2.13, 95%CI 1.12–4.07, p=.022).
