Age of initiation of smokeless tobacco use among young adults: Findings from the population assessment of tobacco and health (PATH) study, 2013–2017

INTRODUCTION: Smokeless tobacco (SLT) use, across all age groups, is most prevalent among young adults in the US. A study estimating the age of initiation of SLT use among young adults is needed amid the changing landscape of tobacco products. METHODS: Secondary analyses of PATH young adults across waves 1–4 were conducted. A total of 10595 young adults who were never SLT users at their first wave of adult participation in PATH (waves 1–3) were included in the analysis. Age of initiation outcomes of ever, past 30-day, and fairly regular SLT use, were assessed prospectively in waves 2–4. Interval censoring Cox regression models were used to assess differences in the age of initiation of each outcome by sex and race/ethnicity, adjusting for other tobacco product use. RESULTS: By the age of 27 years, 4.9%, 3.0%, and 1.9% of young adults reported initiating ever, past 30-day, and fairly regular SLT use, respectively. After controlling for demographic factors and other tobacco use, males initiated each of the SLT outcomes at earlier ages than females; non-Hispanic Blacks initiated each of the SLT use at later ages than non-Hispanic Whites; and Hispanic and non-Hispanic others initiated ever use at later ages than non-Hispanic Whites. CONCLUSIONS: These data suggest that three young adult groups are more likely to initiate use of SLT at earlier ages: males, non-Hispanic Whites, and poly-tobacco users. Knowing the age of SLT initiation outcomes among young adults will educate the public domain, inform SLT use prevention campaigns, and provide a baseline to measure the success of the Tobacco 21 legislation from December 2019.