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.