IntroductionTo examine if perceptions of harmfulness and addictiveness of hookah and cigarettes impact the age of initiation of hookah and cigarettes, respectively, among US youth. Youth (12-17 years old) users and never users of hookah and cigarettes during their first wave of PATH participation were analyzed by each tobacco product (TP) independently. The effect of perceptions of (i) harmfulness and (ii) addictiveness at the first wave of PATH participation on the age of initiation of ever use of hookah was estimated using interval-censoring Cox proportional hazards models.MethodsUsers and never users of hookah at their first wave of PATH participation were balanced by multiplying the sampling weight and the 100 balance repeated replicate weights with the inverse probability weight (IPW). The IPW was based on the probability of being a user in their first wave of PATH participation. A Fay’s factor of 0.3 was included for variance estimation. Crude hazard ratios (HR) and 95% confidence intervals (CIs) are reported. A similar process was repeated for cigarettes.ResultsCompared to youth who perceived each TP as “a lot of harm”, youth who reported perceived “some harm” had younger ages of initiation of these tobacco products, HR: 2.53 (95% CI: 2.87-4.34) for hookah and HR: 2.35 (95% CI: 2.10-2.62) for cigarettes. Similarly, youth who perceived each TP as “no/little harm” had an earlier age of initiation of these TPs compared to those who perceived them as “a lot of harm”, with an HR: 2.23 (95% CI: 1.82, 2.71) for hookah and an HR: 1.85 (95% CI: 1.72, 1.98) for cigarettes. Compared to youth who reported each TP as “somewhat/very likely” as their perception of addictiveness, youth who reported “neither likely nor unlikely” and “very/somewhat unlikely” as their perception of addictiveness of hookah had an older age of initiation, with an HR: 0.75 (95% CI: 0.67-0.83) and an HR: 0.55 (95% CI: 0.47, 0.63) respectively.DiscussionPerceptions of the harmfulness and addictiveness of these tobacco products (TPs) should be addressed in education campaigns for youth to prevent early ages of initiation of cigarettes and hookah.

AimsTo identify, visualize, and describe the prevalence of within-product patterns of tobacco use behaviors for e-cigarettes, cigarettes, and hookah (TP) by 3 age groups (ie, 12-14-year-old, 15-17-year-old, and 18-20-year-old) with U.S. nationally representative data.MethodsIn 2014-2015, never users of each (TP) and age group were followed-up longitudinally between 2015-2019 using five transition states: non-susceptible to (TP) use, susceptible to (TP) use, ever (TP) use, past 30-day (TP) use, and discontinued past 30-day (TP) use. Sankey diagrams were used to graphically visualize patterns in tobacco use behaviors across time.ResultsAmong 12-14-year-old who were never users and susceptible to each TP from 2014-2017, 7% initiated ever e-cigarette use and 9.4% first reported past 30-day use by 2018-2019; 5.8% initiated ever cigarette use and 3% first reported past 30-day cigarette use by 2018-2019; and, 4.5% initiated ever hookah use and 1.0% first reported past 30-day hookah use by 2018-2019. Among 15-17-year-old who were never users and susceptible to each TP from 2014-2017, 4.2% initiated ever e-cigarette use and 9.0% first reported past 30-day use by 2018-2019; 4.5% initiated ever cigarette use and 3% first reported past 30-day cigarette use by 2018-2019; and, 4.5% initiated ever hookah use and 2.4% first reported past 30-day hookah use by 2018-2019. Among 18-20-year-old who were never users and susceptible to each TP from 2014-2017, 3.2% initiated ever e-cigarette use and 3.6% first reported past 30-day e-cigarette use by 2018-2019; 3.0% initiated ever cigarette use and 2.3% first reported past 30-day cigarette use; and, 2.8% initiated ever hookah use and 1.0% first reported past 30-day hookah use by 2018-2019.ConclusionsFrom 2014 to 2019, onset and progression of e-cigarette, cigarette, and hookah use occurred more frequently in 12-14 and 15-17-year-old than in young adults 18-20-year-old.

Despite the negative health consequence of hookah, hookah risk perceptions are misguided among youth. Secondary data analysis of 12–17-year-old never hookah users at their first wave of PATH participation (2013–2019) was performed. The effect of perceptions of hookah harmfulness and addictiveness on the age of initiation ever, past 30-day, and fairly regular hookah use were estimated using interval-censored Cox proportional hazards models. The distribution of the age of initiation of hookah outcomes by perception levels of harmfulness and addictiveness are reported as cumulative incidence and 95% CI. Youth who perceived hookah to be neither harmful nor addictive were 173% more likely to initiate ever, 166% more likely to first report past 30-day use, and 142% more likely to first report fairly regular hookah use at earlier ages compared to youth who considered hookah to be both harmful and addictive. By age 18, 25.5% of youth who perceived hookah as neither harmful nor addictive were estimated to initiate ever hookah use while 9.3% of youth who perceived hookah as harmful and addictive were estimated to initiate ever hookah use. These findings indicate the need to provide prevention and education campaigns to change perceptions of the harmfulness and addictiveness of hookah to delay the age of initiation of hookah use.

Introduction Youth perceptions of harmfulness and addictiveness of e-cigarettes may impact the age that they initiate e-cigarette use, but this has not been investigated previously. Methods Youth (12-17 years old) never e-cigarette users at their first wave of PATH participation (waves 1-3, 2013-2016) were included. PATH questions on absolute perceptions of e-cigarette harmfulness and addictiveness were used as exposures. Interval-censored Cox proportional hazards models were used to estimate the impact of perceptions of harmfulness, and perceptions of addictiveness on (i) the age of initiation of e-cigarette use and (ii) age of first reporting past 30-day e-cigarette use, while controlling for covariates. Results Youth who perceive e-cigarettes as having no/little harm had increased risk of initiating both ever e-cigarette use (AHR = 2.04; 95%CI = 1.74-2.40) and past 30-day e-cigarette use (AHR = 2.64; 95%CI = 2.07-3.37) at earlier ages compared to youth who perceive e-cigarettes as having a lot of harm. Youth who perceive the likelihood of becoming addicted to e-cigarettes to be very/somewhat unlikely had increased risk of an earlier age of both ever (AHR = 1.28; 95%CI = 1.07-1.52) and past 30-day (AHR = 1.36; 95%CI = 1.04-1.79) e-cigarette initiation compared to youth who perceived the likelihood of becoming addicted to e-cigarettes to be somewhat/very likely. Conclusion These results highlight the importance of communicating to youth the potential for health harms and addiction from e-cigarette use in prevention and intervention campaigns, as those with the lowest perceptions of harmfulness and addictiveness had the earliest ages of e-cigarette initiation.

BackgroundPerceptions of cigar products' harmfulness and addictiveness in youth are associated with subsequent cigar product initiation, but their association on the age of initiation of cigar product use is unknown.MethodsThe association of perceptions of harmfulness and addictiveness at youth's first wave of PATH participation (waves 1 or 2 in years 2013–2015) on the age of initiation of (i) ever. (ii) past 30-day, and (iii) fairly regular use of any cigar products (cigarillos, filtered cigars, or traditional cigars) during the followed-up in PATH waves 2–4 (2014–2017) was estimated using weighted interval-censored Cox proportional hazards models. Also, the association of the interaction between perceptions of harmfulness and addictiveness and the age of initiation of any cigar use are reported. Hazard ratios (HR) and 95% confidence intervals (CI) are reported.ResultsAmong youth who had ever heard of cigar products, youth who perceived cigars to be “low-medium harmfulness and low-medium addictiveness” had 60% (HR: 1.60, 95%CI: 1.36–1.89) higher hazard risk to initiate ever cigar product use at an earlier age, and had 46% (HR:1.46, 95%CI: 1.14–1.86) higher hazard risk to initiate past 30-day cigar product use at younger ages than those who perceived cigars to be “high harmfulness and high addictiveness.” Moreover, youth who perceived cigars to be “low-medium harmfulness and high addictiveness” had 33% (HR: 1.33, 95%CI: 1.15–1.53) higher hazard risk to initiate ever cigar product use at younger ages than those who perceived cigars to be “high harmfulness and high addictiveness.” Youth who reported “high harmfulness and low-medium addictiveness” (HR: 0.24, 95% CI: 0.07–0.83) had 76% lower hazard risk to initiate fairly regular use of cigar products at younger ages compared to youth who reported “high harmfulness and high addictiveness.”ConclusionsPrevention and awareness campaigns should reinforce the unique potential for harm and addiction of cigar products to curb cigar product initiation among US youth.

Context Youth tobacco use remains a prominent United States public health issue with a high economic and health burden. Method We pooled never and ever users at youth's first wave of PATH participation (waves 1-3) to estimate age of initiation for hookah, e-cigarettes, cigarettes, traditional cigars, cigarillos, and smokeless tobacco prospectively (waves 2-4). Age of initiation of each tobacco product was estimated using weighted interval-censored survival analyses. Weighted interval censoring Cox-proportional hazards regression models were used to assess the association of ever use of the TP at the first wave of PATH participation, sex, and race/ethnicity on the age of initiation of ever use of each tobacco product. Sensitivity analyses were performed to understand the impact of the recalled age of initiation for the left-censored participants by replacing the recalled age of initiation with a uniform "6" years lower bound. Results The proportion of those who ever used each tobacco product at the first wave of PATH participation ranged from 1.8% for traditional cigars to 10.4% for cigarettes. There was a significant increase in ever use of each tobacco product after the age of 14, with e-cigarettes and cigarettes showing the highest cumulative incidence of initiation by age 21, while smokeless and cigarillos recorded the lowest cumulative incidence by age 21. The adjusted Cox models showed boys initiated at earlier ages for all of these tobacco products except for hookah, which showed no difference. Similarly, apart from ever use of hookah, non-Hispanic White youth were more likely to initiate each tobacco product at earlier ages compared to Hispanic, non-Hispanic Black, and non-Hispanic Other youth. Conclusion The increased sample size and the inclusion of ever users yielded greater precision for age of initiation of each tobacco product than analyses limited to never users at the first wave of PATH participation. These analyses can help elucidate population selection criteria for estimating the age of initiation of tobacco products.

Previous research has established an association between internalizing and externalizing problems with e-cigarette use in youth. Secondary analysis of Population Assessment of Tobacco and Health youth waves 1-4(2013-2017). Age of initiation of ever e-cigarette use and age of first report of past 30-day e-cigarette use were prospectively estimated among never e-cigarette users(waves 1-3). Weighted interval-censoring multivariable Cox proportional hazard models were fit to assess differences in each e-cigarette outcome among youth with internalizing and externalizing problems, as well as the interaction between internalizing and externalizing problems, while adjusting for covariates. Weighted interval-censoring survival analyses estimated the age of initiation of ever and age of first report of past 30-day e-cigarette use stratified by internalizing and externalizing problems. Among youth never e-cigarette users, those with high internalizing problems and high externalizing problems had increased risk of initiating ever e-cigarette use at earlier ages compared to youth with none/low internalizing and externalizing problems, respectively. Youth with high internalizing problems and high externalizing problems had increased risk of first reporting past 30-day e-cigarette use at earlier ages compared to youth with none/low internalizing problems, respectively. By age 17, 36.3% of youth with high internalizing problems and 38.5% of youth with high externalizing problems initiated ever e-cigarette use. By age 17, 16.8% of youth with high internalizing and 18.7% of youth with high externalizing problems first reported past 30-day e-cigarette use. Youth with internalizing and externalizing problems should be screened for e-cigarette use and provided with proper resources to prevent onset of e-cigarette use.

SignificanceYoung adults, especially those who identify as racial/ethnic minorities, are legal targets of the tobacco industry. Cigarillo initiation is a risk among these vulnerable groups. Estimating the age of initiation of cigarillo use among young adults may inform the timing of prevention interventions.MethodsWeighted interval-censored survival analyses of the Population Assessment of Tobacco and Health (PATH) young adult (ages 18-24 at their first wave of adult participation) annual datasets were conducted (2013-2017). Young adult never cigarillo users (n = 7,101; represents N = 24,023,488) at their first wave of adult participation (2013-2016) were followed-up through 2014-2017 to estimate the age of initiation of ever, past 30-day and fairly regular cigarillo use outcomes. Differences by sex and by race/ethnicity, accounting for previous use of other tobacco products and marijuana and blunt use, were assessed using weighted interval-censored Cox proportional hazards models.ResultsAmong PATH young adults, by age 21, 5.8% initiated ever cigarillo use, 4.1% initiated past 30-day cigarillo use, and 1.4% initiated fairly regular cigarillo use. By age 26, 15% initiated ever cigarillo use, and 10.4% initiated past 30-day cigarillo use. Males had higher risk of initiating ever (AHR: 1.63, 95% CI: 1.37-1.95) and past 30-day cigarillo use (AHR: 1.65, 95% CI: 1.32-2.06) at earlier ages than females. Non-Hispanic Blacks had higher risk of initiating ever (AHR: 2.81, 95% CI: 2.26-3.50), past 30-day (AHR: 4.88, 95% CI: 2.95-5.09) and fairly regular cigarillo use (AHR: 4.62, 95% CI: 2.70-7.93) at earlier ages than non-Hispanic Whites. Hispanics had higher risk of initiating past 30-day cigarillo use at earlier ages than non-Hispanic Whites (AHR: 1.51, 95% CI: 1.12-2.03). Non-Hispanic Other race (i.e., Asian, multiracial, etc.) had lower risk of initiating ever (AHR: 0.43, 95% CI: 0.28-0.65) and past 30-day cigarillo use (AHR: 0.40, 95% CI: 0.26-0.63) at earlier ages than Non-Hispanic Whites.ConclusionAlong with those aged 21 and younger, interventions should target young adults over the age of 21, specifically males, non-Hispanic Black and Hispanic young adults, to stall initiation and progression of cigarillo use behaviors.

Objectives To prospectively estimate the age of cigarette initiation among young adults (18-24 years old) who were never cigarette users at their first wave of adult study participation overall, by sex, and by race/ethnicity given recent increases in cigarette initiation occurring in young adulthood. Methods Secondary analyses were conducted using the PATH restricted-use adult datasets among young adult never users of cigarettes in waves 1-3 (2013-2016) with outcomes followed-up in waves 2-4 (2014-2017). Interval censoring survival methods were used to estimate the age of initiation of (i) ever, (ii) past 30-day, and (iii) fairly regular cigarette use. Among never cigarette users when they first entered the adult study, interval censoring Cox proportional hazard models were used to explore differences in the estimated age of initiation of the three cigarette use outcomes by sex and by race/ethnicity, controlling for the effect of previous e-cigarette use and the total number of other tobacco products ever used (0-5 products) before cigarette initiation outcomes. Results Among the young adults who were never cigarette users at their first wave of adult participation, the highest increase in cigarette initiation occurred between 18 and 19 years old. By age 21, 10.6% (95% CI: 9.5-11.7) initiated ever cigarette use, 7.7% (95% CI: 6.1-8.1) initiated past 30-day of cigarette use, and 1.9% (95% CI: 1.4-2.5) initiated fairly regular cigarette use. After controlling for other tobacco products: (a) males were 83% more likely to initiate past 30-day cigarette use at earlier ages than females; (b) Hispanic and Non-Hispanic Black young adults had increased risk to initiate past 30-day cigarette use at earlier ages than Non-Hispanic White young adults (62% and 34%, respectively). Conclusions The substantial amount of cigarette initiation among young adults reinforces the need for prevention strategies among this population. Although, interventions are needed for all young adult populations, strategies should target 18-21-year-olds, with potentially differential prevention targets by sex and by race/ethnicity.

Introduction Initiation of tobacco products is increasing in young adulthood. This study prospectively estimated the age of onset of susceptibility to cigarettes, e-cigarettes, hookah, smokeless tobacco, and cigarillos among young adults, which is a cognitive precursor to initiation. Methods Secondary data analyses of the Population Assessment of Tobacco and Health (PATH) study, a nationally representative longitudinal cohort study of US adults. Young adults (18-24 years) who were non-susceptible to each tobacco product (cigarettes, e-cigarettes, hookah, smokeless tobacco, and cigarillos) at waves 2 or 3 were followed-up into waves 3-4 to prospectively estimate the age of onset of susceptibility to each tobacco product. Weighted interval-censored survival methods and interval-censored Cox regression models were implemented to estimate the age of onset of susceptibility, and to estimate differences in the hazard function by sex and by race/ethnicity, while controlling for the total number of other tobacco products ever used at their first wave of participation in PATH. Results By age 21, 16.5%, 16.0%, 12.6%, 12.4%, and 5.9% of young adults reported onset of susceptibility to hookah, e-cigarettes, cigarillos, cigarettes, and smokeless tobacco, respectively. Among young adults who were non-susceptible to each tobacco product at waves 2 or 3, the highest increase in onset of susceptibility occurred between ages 18 and 19 for cigarettes, e-cigarettes, and hookah, while the highest increase in onset of susceptibility occurs between ages 22 and 23 for cigarillos. Young adult males had increased risk of onset of susceptibility to cigarillos and smokeless tobacco at earlier ages than young adult females. Differences in onset of susceptibility to each tobacco product were also observed by race/ethnicity among young adults. Conclusions With the changing landscape of tobacco products, monitoring the age of onset of susceptibility of tobacco product use among non-susceptible young adults longitudinally is critical to prevent initiation. Communication and education campaigns tailored to address differences in susceptibility among young adults by tobacco product and sociodemographic factors will be useful.

Earlier exposure to binge drinking and tobacco use is associated with higher odds of substance use disorders. Using national youth data from the PATH study, we prospectively estimate the age of initiating past 30-day use of (1) cigarettes, e-cigarettes, and binge drinking, and (2) cigarettes, cigarillos, and binge drinking. Cox proportional hazard models were used to estimate differences in the age of initiation by sex, race/ethnicity, and previous use of other tobacco products. By age 21, 4.4% (95% CI: 3.7–5.2) and 2.0% (95% CI: 1.2–2.8) of youth reported initiation of past 30-day use outcomes (1) and (2), respectively. After controlling for sex and previous use of other tobacco products, statistically significant differences in the age of initiation by race/ethnicity were found for each outcome: Hispanic and non-Hispanic Black youth were less likely than non-Hispanic White youth to initiate past 30-day use of both outcomes (1) and (2) at earlier ages. Although the initiation of both outcomes remained relatively low by age 21, these incidences represent 1.56 million and 700,000 youth, respectively. This study provides the public with evidence to identify the particular ages at which education campaigns may be most effective to prevent youth from initiating these three substances. Further research is needed to estimate the age of initiation of other dual tobacco use patterns with binge drinking.

This cohort study uses data from the Population Assessment of Tobacco and Health (PATH) study waves 1 to 4 to assess at what age young people aged 12 to 17 years initiate cigarette use.

Objective To prospectively estimate the age of initiation of ever, past 30-day, and fairly regular hookah use among young adults (ages 18-24) overall, by sex, by race/ethnicity, and to explore the association of prior use of other tobacco products with these hookah use behaviors. Methods Secondary data analyses of the first four waves (2013-2017) of the PATH study, a nationally representative longitudinal cohort study of US young adults. Young adult never hookah users at the first wave of adult participation in PATH waves 1-3 (2013-2016) were followed-up into waves 2-4 (2014-2017) to estimate the age of initiation of three outcomes: (i) ever use, (ii) past 30-day use, and (iii) fairly regular hookah use. Weighted interval-censoring Cox proportional hazards regression models were used to examine the differences in the estimated age of initiation by sex and by race/ethnicity while controlling for the total number of other tobacco products ever used at participants' first wave of PATH participation. In addition, to examine if prior use of other tobacco products was associated with the age of hookah initiation behaviors, six additional Cox models are reported for each hookah initiation behaviors. Results The largest increase in hookah use occurred between ages 18 and 19: 5.8% for ever use and 2.7% for past 30-day hookah use. By age 21, 10.5%, 4.7% and 1.2% reported initiation of ever, past 30-day and fairly regular hookah use, respectively. There were statistically significance differences in the age of initiation of hookah use behaviors by race/ethnicity. Conclusion Educational interventions should target young adults before the age of 21, focusing efforts specifically on males, non-Hispanic Blacks and Hispanics, to stall initiation and progression of hookah use behaviors.

Introduction There is a lack of research prospectively estimating the age of e-cigarette initiation in U.S. young adults. Methods Secondary analysis of PATH young adults across 2013-2017 (waves 1-4) were conducted. We prospectively estimated age of initiation of: ever, past 30-day, and fairly regular e-cigarette use using weighted interval-censoring survival analyses. Interval-censoring Cox proportional hazard models adjusting for sex, race/ethnicity, and previous use of six other tobacco products (cigarettes, traditional cigars, filtered cigars, cigarillos, hookah, and smokeless tobacco) were fitted for each of the three e-cigarette initiation outcomes. Results Among never e-cigarette users, by age 21, 16.8% reported ever use, 7.2% reported past 30-day use, and 2.3% reported fairly regular e-cigarette use. Males had increased risk of initiating ever, past 30-day, and fairly regular e-cigarette use at earlier ages compared to females. Hispanic young adults had increased risk of initiating ever and past 30-day e-cigarette use at earlier ages compared to Non-Hispanic White young adults. Previous use of other tobacco products before e-cigarette initiation increased the risk of an earlier age of e-cigarette initiation. Conclusion Prevention and education campaigns should focus on young adults in order to alleviate the public health burden of initiating e-cigarette use at earlier ages.

Objective: This study reports the prospectively estimated age of initiation of susceptibility to, ever, past 30-day, and fairly regular hookah use. Design: Secondary data analyses of the first four waves (2013-2017) of the PATH study, a nationally representative longitudinal cohort study of US youth (ages 12-17). Methods: Youth who were never hookah users at their first wave of participation were identified (n = 16,678; N = 31,136,834). Four outcomes were analyzed, age of first report of: (i) susceptibility to use, (ii) ever use, (iii) past 30-day use, and (iv) fairly regular hookah use. The age of hookah initiation of each outcome was estimated. Weighted interval censoring survival analyses and Cox regression models were conducted to estimate the age of initiation of each hookah use outcome, and to estimate differences in age of initiation by sex and by race, respectively. Results: Around 11% of youth were classified as susceptible to hookah use by 13 years of age, 8% reported initiating ever hookah use by age 17, almost 10% reported initiating past 30-day hookah use by age 19, and 3% reported initiating fairly regular hookah use by age 20. Females and Hispanics were at higher risk of becoming susceptible to and ever hookah use at earlier ages compared to males and Non-Hispanic White youth. Conclusion: Education, communication campaigns, and proven culturally targeted tobacco interventions that reach youth at ages before they first become susceptible or start using hookah use are needed to prevent the onset of hookah use among vulnerable youth.

SignificanceEarly age of initiation of tobacco use is associated with sustained tobacco use and lower rates of smoking cessation. Although much is known about age of initiation of cigarette use, much less is known about the age of initiation of cigar product use among youth.MethodsSurvival analyses of the Population Assessment of Tobacco and Health youth annual datasets (ages 12-17) from 2013 to 2017 were conducted for any cigar product use, cigarillos or filtered cigars, and traditional cigars across four cigar use outcomes, age of initiation of: susceptibility to use, ever use, past 30-day use and "fairly regular" use. An interval censoring survival method was implemented to estimate the probability of each outcome for age of initiation of each cigar product overall. Differences in age of initiation by sex and race/ethnicity were assessed using weighted Cox proportional hazards models for interval-censored data.ResultsFor each outcome across the three cigar products, striking increases in the probability of initiation begin before 17 years old. For cigarillo or filtered cigars, males had a higher risk of onset of susceptibility to use, initiating ever use, and initiating past 30-day use at earlier ages than females. Compared to Non-Hispanic Whites, Hispanic and Non-Hispanic Other had lower risk of initiating ever use and past 30-day use at earlier ages. Non-Hispanic Black youth had higher risk of initiating past 30-day use and "fairly regular" use than Non-Hispanic White youth at earlier ages. Similar findings are reported for any cigar use and traditional cigar use.ConclusionDevelopmentally and culturally appropriate cigar use interventions and communication campaigns should be provided to youth before 17 years of age to prevent the onset and progression of cigar products. Regulatory policies that reduce appeal of all cigar products should be implemented to curb cigar initiation among youth.