Trends in smoking initiation in Canada: Does non-inclusion of young adults in tobacco control strategies represent a missed opportunity?

OBJECTIVES Young adults face high prevalence rates for smoking. Recent evidence suggests that many people initiate smoking during young adulthood, but little is currently known about trends in initiation rates for this age group. METHODS We examined rates of initiation to first cigarette (FC) and daily smoking (DS) during youth (5-17 years) and young adulthood (18-25 years) using nationally representative data from the 2001, 2003, 2005, 2007, 2009, 2011 and 2013 cycles of the Canadian Community Health Survey. We included all participants aged 25-26 to obtain seven mutually exclusive retrospective cohorts (n = 16 216). We used logistic regression to examine four correlates of smoking - sex, education, poverty status, and immigration status - and whether these factors modify time trends in smoking. RESULTS We found that initiation rates decreased during youth (p < 0.001 for FC, p = 0.02 for DS) but not during young adulthood (p = 0.94 for FC, p = 0.28 for DS). We found that men and respondents with fewer educational credentials had relatively higher odds of initiating during young adulthood. Trends in young adulthood stayed constant across subgroups. Trends in youth were modified by education: participants who did not complete high school had no decrease in initiation to FC and DS while those with post-secondary education experienced a decrease in both outcomes. CONCLUSION Tobacco control has failed to address smoking initiation during young adulthood. Given the considerable amount of initiation that occurs during this period, practitioners and policy-makers should direct more of their planning toward young adults.