Cigarette Smoking Trajectories From Sixth to Twelfth Grade: Associated Substance Use and High School Dropout

Young Adults' Exposure to and Engagement With Tobacco-Related Social Media Content and Subsequent Tobacco Use

INTRODUCTION

Nicotine/tobacco social media content may increase young people's risk for use. This study examined prospective associations between exposure to and engagement with nicotine/tobacco-related social media content and nicotine/tobacco use among young adults.

AIMS AND METHODS

Young adults (N = 2080) originally recruited from Southern California high schools for a prospective cohort study reported frequency of viewing and posting nicotine/tobacco content on four social media platforms (Facebook, Instagram, Twitter, and YouTube). Participants also reported frequency of seeing nicotine/tobacco posts from friends, seeing nicotine/tobacco posts from influencers or celebrities, and liking nicotine/tobacco posts. Within subsamples of nicotine/tobacco never users (n = 794), past users (n = 897) and current users (n = 389), analyses examined associations of baseline (May-October 2020) social media content exposure and engagement with follow-up (January-June 2021) tobacco use initiation (among never users), resumption (among past users), and continuation (among current users), adjusting for sociodemographic and socioenvironmental characteristics.

RESULTS

Never users who saw nicotine/tobacco posts from friends (Adjusted Odds Ratio [AOR] = 2.91 [95% Confidence Interval [CI]: 1.46, 5.82], p = .002) or from celebrities or influencers (AOR = 2.77 [1.32, 5.84], p = .007) were significantly more likely to initiate nicotine/tobacco use than their peers. Among past users, posting nicotine/tobacco content at baseline was associated with use resumption (AOR = 1.77 [1.12, 2.80], p = .014). Content exposure and engagement were not associated with nicotine/tobacco use continuation among current users (p-values > .05).

CONCLUSIONS

Seeing nicotine/tobacco posts from friends, influencers, or celebrities was associated with greater odds of tobacco use initiation, but not resumption or continuation, 6 months later. Young adults with past nicotine/tobacco use who post about nicotine/tobacco may be at elevated risk for resuming use.

IMPLICATIONS

Young adults with exposure to nicotine/tobacco social media content were more likely than their peers to initiate nicotine/tobacco use 6 months later. Past nicotine/tobacco users who reported posting about nicotine/tobacco on social media at baseline were more likely than their peers to resume nicotine/tobacco use. Among young adults with current nicotine/tobacco use at baseline, social media activity did not predict odds of nicotine/tobacco use continuation at follow-up. Nicotine/tobacco content on social media should be restricted to reduce young people's chances of nicotine/tobacco use initiation or resumption.

Does smoking cause lower educational attainment and general cognitive ability? Triangulation of causal evidence using multiple study designs

BACKGROUND

Observational studies have found associations between smoking and both poorer cognitive ability and lower educational attainment; however, evaluating causality is challenging. We used two complementary methods to explore this.

METHODS

We conducted observational analyses of up to 12 004 participants in a cohort study (Study One) and Mendelian randomisation (MR) analyses using summary and cohort data (Study Two). Outcome measures were cognitive ability at age 15 and educational attainment at age 16 (Study One), and educational attainment and fluid intelligence (Study Two).

RESULTS

Study One: heaviness of smoking at age 15 was associated with lower cognitive ability at age 15 and lower educational attainment at age 16. Adjustment for potential confounders partially attenuated findings (e.g. fully adjusted cognitive ability β -0.736, 95% CI -1.238 to -0.233, p = 0.004; fully adjusted educational attainment β -1.254, 95% CI -1.597 to -0.911, p < 0.001). Study Two: MR indicated that both smoking initiation and lifetime smoking predict lower educational attainment (e.g. smoking initiation to educational attainment inverse-variance weighted MR β -0.197, 95% CI -0.223 to -0.171, p = 1.78 × 10^-49). Educational attainment results were robust to sensitivity analyses, while analyses of general cognitive ability were less so.

CONCLUSION

We find some evidence of a causal effect of smoking on lower educational attainment, but not cognitive ability. Triangulation of evidence across observational and MR methods is a strength, but the genetic variants associated with smoking initiation may be pleiotropic, suggesting caution in interpreting these results. The nature of this pleiotropy warrants further study.

Cigarette smoking trajectories in adolescent smokers: Does the time axis metric matter?

INTRODUCTION

Most studies modeling adolescent cigarette smoking trajectories use age as the time axis, possibly obscuring depiction of the natural course of cigarette smoking. We used a simulated example and real data to contrast smoking trajectories obtained from models that used time since smoking onset or calendar time (age) as the time axis.

METHODS

Data were drawn from a longitudinal investigation of 1293 grade 7 students (mean age 12.8 years) recruited from 10 high schools in Montreal, Canada in 1999-2000, who were followed into young adulthood. Cigarette consumption was measured every 3 months during high school, and again at mean age 20.4 and 24.0. Analyses using time since onset of smoking as the time metric was restricted to 307 incident smokers; analysis using calendar time included 645 prevalent and incident smokers. Smoking status and nicotine dependence (ND) were assessed at mean age 20.4 and 24.0. Simulated data mimicked the real study during high school.

RESULTS

Use of different time metrics resulted in different numbers and shapes of trajectories in the simulated and real datasets. Participants in the calendar time analyses reported more ND in young adulthood, reflecting inclusion of 388 prevalent smokers who had smoked for longer durations.

CONCLUSIONS

Choosing the right time metric for trajectory analysis should be balanced against research intent. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across age during a given time period.

IMPLICATIONS

This study uses simulated and real data to show that trajectory analyses of cigarette smoking that use calendar time (e.g., age) versus time since onset as the time axis metric tell a different story. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across age during a given time period. Choosing the right time metric should be balanced against research intent.

Longitudinal pathways of exclusive and polytobacco cigarette use among youth, young adults and adults in the USA: findings from the PATH Study Waves 1-3 (2013-2016)

OBJECTIVE

Cigarettes are the most harmful and most prevalent tobacco product in the USA. This study examines cross-sectional prevalence and longitudinal pathways of cigarette use among US youth (12-17 years), young adults (18-24 years) and adults 25+ (25 years and older).

DESIGN

Data were drawn from the first three waves (2013-2016) of the Population Assessment of Tobacco and Health Study, a nationally representative, longitudinal cohort study of US adults and youth. Respondents with data at all three waves (youth, N=11 046; young adults, N=6478; adults 25+, N=17 188) were included in longitudinal analyses.

RESULTS

Among Wave 1 (W1) any past 30-day (P30D) cigarette users, more than 60%, persistently used cigarettes across three waves in all age groups. Exclusive cigarette use was more common among adult 25+ W1 P30D cigarette users (62.6%), while cigarette polytobacco use was more common among youth (57.1%) and young adults (65.2%). Persistent exclusive cigarette use was the most common pathway among adults 25+ and young adults; transitioning from exclusive cigarette use to cigarette polytobacco use was most common among youth W1 exclusive cigarette users. For W1 youth and young adult cigarette polytobacco users, the most common pattern of use was persistent cigarette polytobacco use.

CONCLUSIONS

Cigarette use remains persistent across time, regardless of age, with most W1 P30D smokers continuing to smoke at all three waves. Policy efforts need to continue focusing on cigarettes, in addition to products such as electronic nicotine delivery systems that are becoming more prevalent.

Trajectories and determinants of adolescents' nicotine product use risk among U.S. adolescents in a nationally representative sample of longitudinal cohort

INTRODUCTION

To understand the heterogeneous longitudinal trends in adolescent nicotine product use risk, we investigated the trajectories and determinants of nicotine product use among adolescents.

METHODS

Using Waves 1-4 (Years 2013-2018) data of the Population Assessment of Tobacco and Health Study, we conducted group-based trajectory modeling to identify groups of individuals who followed homogeneous trajectories of nicotine product use risk over time and weighted multinomial logistic regression to examine relative risk ratios (RRRs) of different levels of predictors of group membership in each identified trajectory.

RESULTS

For adolescents, who were 12-17 years old at baseline (N = 10,086), 5 trajectory groups emerged: (1) nonusers (73.7%); (2) stable low to moderate risk of developing poly use (5.0%); (3) gradual increase in risk of poly use (12.8%); (4) rapid linear increase in risk of poly use until Wave 3 and then plateauing for cigarettes or slightly diminishing for e-cigarettes and other tobacco products at Wave 4 (4.6%); and (5) stable moderate to high risk of poly use (3.9%). Adolescents who used social network services daily at Wave 1 were more likely to belong to each of the four trajectory groups compared to nonusers (RRRs ranging from 1.43 to 2.04).

CONCLUSIONS

The current study findings imply that the majority of adolescents who initiated any nicotine product use have an elevated risk of transitioning to poly users. Risk and protective factors for different risk patterns are discussed.

A systematic review of cigarette smoking trajectories in adolescents

Trajectory analyses differentiate subgroups of smokers based on early patterns of cigarette use, but no study has summarized this literature. We systematically reviewed the literature on adolescent cigarette smoking trajectories to document the number and shapes of trajectories identified, assess if certain study characteristics influence the number or shapes of trajectories identified, summarize factors associated with and outcomes of trajectory group membership, and assess whether the results of trajectory analyses help identify windows of opportunity for intervention. We searched PubMed and EMBASE (1/1/1980 to 1/11/2018) and identified 1695 articles. Forty-three articles with data from 37 unique datasets were retained. Each trajectory was categorized into one of three groups (i.e., low-stable, increasing, other). Number of trajectories ranged from 2 to 6 (mode = 4); 44-76% of participants were low-stable cigarette consumers, 11-21% increased consumption, and 3-11% were categorized as "other." Number of data points, smoking indicator used, and time axis influenced the number of trajectories identified. Only two articles depicted the natural course of smoking since onset. Factors associated with trajectory membership included age, sex/gender, race/ethnicity, parental education, behavior problems, depression, academic performance, baseline cigarette use, parental and friends smoking, alcohol use, and cannabis use. Outcomes included illicit drug and alcohol use. Beyond parsimoniously describing cigarette smoking patterns, it is not clear whether trajectory analyses offer increased insight into the natural course, determinants or outcomes of cigarette smoking in ways that inform the development of intervention.

Relationship Between Alcohol-related Family Adversity, Alcohol Use Across Adolescence, and Mental States Recognition in Young Adulthood

OBJECTIVES

Although a theoretical link between childhood adversity and mental states recognition has been established, empirical findings are mixed. Some prior work indicates that childhood adversity might enhance, preserve, or reduce mentalization skills in selected at-risk populations. In the current study, we examine whether the presence of risky alcohol use during adolescence moderates the association between childhood alcohol-related family adversity and mental states recognition in young adulthood.

METHODS

Secondary data analysis was conducted on 266 young adults who participated in the Michigan Longitudinal Study-a multiwave prospective study on at-risk youth. Children were assessed after initial recruitment (wave 1, target child age range 3-5 years), with assessments repeated every 3 years using parallel measures. The current study focuses on data spanning wave 2 (age range 7-9 years) through wave 6 (target child age range 18-21 years). A family adversity index was derived reflecting exposure to a maladaptive family environment during childhood as assessed at wave 1. An alcohol use risk factor was established reflecting early problem alcohol use during adolescence (target child age range 12-17 years). Mental states recognition was measured with a computerized version of the Reading the Mind in the Eyes Task (RMET) at wave 6. Information about demographics, psychopathological symptoms, and IQ was obtained. The alcohol use risk factor was tested as a potential moderator of the association between childhood family adversity on RMET performance during young adulthood.

RESULTS

Alcohol use risk moderated the relationship between childhood alcohol-related family adversity, and negative and neutral mental states recognition. Specifically, childhood family adversity was positively associated with neutral mental states recognition among participants high in alcohol risk (P = 0.03) and positively associated with negative mental states recognition among participants at average (P = 0.02) and high (P = 0.002) levels of alcohol risk.

CONCLUSIONS

Findings indicate that history of childhood adversity may actually improve young adult negative and neutral mental states recognition among those demonstrating high levels of risky alcohol use, as substance use may serve as an external self-regulatory tool. Clinical interventions that target enhancing metacognitive competence and emotion regulation could ultimately help to break the cycle of alcohol-related family adversity.

The Influence of Parental Support and Community Belonging on Socioeconomic Status and Adolescent Substance Use over Time

Background. Despite a growing trend in community-based research, studies investigating the influence of multi-level community factors on individual-level outcomes remain relatively sparse. Objective. The current study aimed to extend this literature by investigating the association between community disadvantage measured at the community level, and adolescents' substance use over time. Additionally, this study also investigated the influence of parental support and community belonging on this association. Methods. Data were drawn from Waves I and III of the National Longitudinal Study of Adolescent to Adult Health data set. Using a multi-level modeling approach, we tested the association between community disadvantage and substance use during adolescence. Second, to determine if this association held longitudinally, we examined the influence of community disadvantage on substance use over time, into young adulthood. Lastly, we tested the moderating effects of parental support and community belonging on the association between community disadvantage and substance use during adolescence and young adulthood. Results. Findings suggested that individuals experiencing the greatest disadvantage were less likely to engage in substance use in comparison to those experiencing the greatest advantage. Conclusions/Importance. Differential effects of parental support and community belonging on community disadvantage and substance use were also found. Implications of these findings are discussed.

Time-varying Effects of GABRG1 and Maladaptive Peer Behavior on Externalizing Behavior from Childhood to Adulthood: Testing Gene × Environment × Development Effects

Engagement in externalizing behavior is problematic. Deviant peer affiliation increases risk for externalizing behavior. Yet, peer effects vary across individuals and may differ across genes. This study determines gene × environment × development interactions as they apply to externalizing behavior from childhood to adulthood. A sample (n = 687; 68% male, 90% White) of youth from the Michigan Longitudinal Study was assessed from ages 10 to 25. Interactions between γ-amino butyric acid type A receptor γ1 subunit (GABRG1; rs7683876, rs13120165) and maladaptive peer behavior on externalizing behavior were examined using time-varying effect modeling. The findings indicate a sequential risk gradient in the influence of maladaptive peer behavior on externalizing behavior depending on the number of G alleles during childhood through adulthood. Individuals with the GG genotype are most vulnerable to maladaptive peer influences, which results in greater externalizing behavior during late childhood through early adulthood.

"Phantom smokers": Young cigarillo users who do not identify as smokers

INTRODUCTION

Many young consumers of non-cigarette tobacco products, such as cigarillos, do not identify as smokers. These "phantom smokers" tend to underestimate risks to health and feel little urgency to quit. This study examines the prevalence and characteristics of phantom smoker status among young cigarillo users.

METHODS

An online survey was conducted among 14-28 year olds who smoke at least 2 cigarillos per week. Phantom smoker status was determined by a negative response to "Do you consider yourself a smoker?" Other variables included smoking frequency, group smoking and sharing, and confidence in ability to quit. Associations between smoker identity and these variables were tested using chi square, independent samples t-tests and multivariable logistic regression.

RESULTS

Of 1089 respondents, 242 (22%) were identified as phantom smokers. Phantoms smoked half as many cigarillos per week as identified smokers (M = 4.75, SD = 5.11 vs. M = 11.33, SD = 0.88, p < .001) and phantoms were more likely to smoke only when sharing (39.7% vs 21.8%, p < .001). While 59.5% of identified smokers also smoked cigarettes, only 33.5% of phantoms did so (p < .001). Most phantom smokers (83.8%) were unconcerned about addiction. Phantoms also expressed greater confidence in their ability to quit (M = 4.40, SD = 0.98) than did identified smokers (M = 3.72, SD = 1.25, p < .001).

CONCLUSIONS

Despite regular cigarillo use, over 20% of respondents did not identify as smokers. Cigarillo smoking, along with non-daily and shared use, should be routinely assessed among youth. Phantom smokers' lack of concern about addiction and high confidence in their ability to quit may render conventional messages about smoking risk ineffective.

Ethnic identity and substance use in multiracial youth: the moderating role of support networks

Background: Substance use in multiracial adolescents exceeds rates identified in the general population. Despite this fact, there is limited research examining risk and protective factors for multiracial substance use. Objectives: The current study examined the moderating effect of social support on the relationship between ethnic identity and substance use in a sample of multiracial adolescent youth. Methods: Multiracial youth (N = 523) completed a survey that asked questions related to their ethnic identity, perceived social support, and substance use. A series of path analyses were conducted to test the hypothesized relationships between ethnic identity, social support, and substance use. Results: Analyses indicated that ethnic affirmation was negatively related to frequency of, but not quantity of substance use. Teacher support was negatively related to both frequency and quantity of substance use, while parent support was only related to frequency. Further, teacher and parent support emerged as moderators of ethnic affirmation and frequency and quantity of substance use respectively. Conclusions/Importance: Our findings add to the current understandings of the relationship between ethnic identity, social support, ethnic identity, and substance use among the understudied multiracial adolescent population.

Retention strategies in longitudinal cohort studies: a systematic review and meta-analysis

BACKGROUND

Participant retention strategies that minimise attrition in longitudinal cohort studies have evolved considerably in recent years. This study aimed to assess, via systematic review and meta-analysis, the effectiveness of both traditional strategies and contemporary innovations for retention adopted by longitudinal cohort studies in the past decade.

METHODS

Health research databases were searched for retention strategies used within longitudinal cohort studies published in the 10-years prior, with 143 eligible longitudinal cohort studies identified (141 articles; sample size range: 30 to 61,895). Details on retention strategies and rates, research designs, and participant demographics were extracted. Meta-analyses of retained proportions were performed to examine the association between cohort retention rate and individual and thematically grouped retention strategies.

RESULTS

Results identified 95 retention strategies, broadly classed as either: barrier-reduction, community-building, follow-up/reminder, or tracing strategies. Forty-four of these strategies had not been identified in previous reviews. Meta-regressions indicated that studies using barrier-reduction strategies retained 10% more of their sample (95%CI [0.13 to 1.08]; p = .01); however, studies using follow-up/reminder strategies lost an additional 10% of their sample (95%CI [- 1.19 to - 0.21]; p = .02). The overall number of strategies employed was not associated with retention.

CONCLUSIONS

Employing a larger number of retention strategies may not be associated with improved retention in longitudinal cohort studies, contrary to earlier narrative reviews. Results suggest that strategies that aim to reduce participant burden (e.g., flexibility in data collection methods) might be most effective in maximising cohort retention.

Determinants of High-School Dropout: A Longitudinal Study in a Deprived Area of Japan

Background

Our objective in this study was to find determinants of high-school dropout in a deprived area of Japan using longitudinal data, including socio-demographic and junior high school-period information.

Methods

We followed 695 students who graduated the junior high school located in a deprived area of Japan between 2002 and 2010 for 3 years after graduation (614 students: follow-up rate, 88.3%). Multivariable log-binomial regression models were used to calculate the prevalence ratios (PRs) for high-school dropout, using multiple imputation (MI) to account for non-response at follow-up.

Results

The MI model estimated that 18.7% of students dropped out of high school in approximately 3 years. In the covariates-adjusted model, three factors were significantly associated with high-school dropout: ≥10 days of tardy arrival in junior high school (PR 6.44; 95% confidence interval [CI], 1.69–24.6 for “10–29 days of tardy arrival” and PR 8.01; 95% CI, 2.05–31.3 for “≥30 days of tardy arrival” compared with “0 day of tardy arrival”), daily smoking (PR 2.01; 95% CI, 1.41–2.86) and severe problems, such as abuse and neglect (PR 1.66; 95% CI, 1.16–2.39). Among students with ≥30 days of tardy arrival in addition to daily smoking or experience of severe problems, ≥50% high-school dropout rates were observed.

Conclusions

Three determinants of high-school dropout were found: smoking, tardy arrival, and experience of severe problems. These factors were correlated and should be treated as warning signs of complex behavioral and academic problems. Parents, educators, and policy makers should work together to implement effective strategies to prevent school dropout.

Adolescent smokers' response to reducing the nicotine content of cigarettes: Acute effects on withdrawal symptoms and subjective evaluations

BACKGROUND

Mandating a reduction in the nicotine content of cigarettes to a minimally addictive level could dramatically reduce smoking rates in the US. However, little is known about the effects of reduced nicotine content cigarettes in adolescents.

METHODS

Following overnight abstinence, adolescent daily smokers (ages 15-19, n = 50) reported on their craving, withdrawal, and positive and negative affect pre- and post- ad lib smoking of one cigarette containing varying nicotine content (15.8, 5.2, 1.3 and 0.4 mg/g of tobacco) in the laboratory and reported their subjective evaluations of each cigarette. Carbon monoxide (CO) boost from pre- to post-cigarette was calculated to determine if lower-nicotine cigarettes led to differential acute changes in toxicant exposure.

RESULTS

All four nicotine cigarette types significantly reduced abstinence-induced craving, withdrawal, and negative affect (all p's < .05). Mixed models evaluating the effect of nicotine content, with nicotine dependence level and gender included as covariates, revealed a significant effect of nicotine content on craving and subjective evaluations: higher nicotine content resulted in greater reductions in craving and increases in both positive and negative subjective evaluations. There were no significant effects of nicotine dose on withdrawal symptoms, negative affect, or CO boost.

CONCLUSIONS

These results suggest that lower nicotine cigarettes might result in reduced abuse liability compared to higher nicotine content cigarettes due to reduced positive subjective effects, while still reducing withdrawal, in adolescents. These results highlight the potential feasibility of this policy approach and support continued research on how a nicotine reduction policy may affect adolescent smoking patterns.

Ethnic Differences in Cigarette Use Trajectories and Health, Psychosocial, and Academic Outcomes

PURPOSE

Cigarette smoking among youth is associated with poorer health and psychosocial outcomes. However, few studies address how smoking may differentially relate to the emergence of disparities in functioning across races/ethnicities over adolescence.

METHODS

Youth (n = 2,509) were surveyed eight times from ages 11 to 18. We measured cigarette use, academic and social functioning, mental and physical health, and delinquency. Sequelae of change models controlled for sociodemographic factors, and tested whether intercept and slope for smoking trajectories were associated with outcomes at the end of high school, and examined racial/ethnic differences in outcomes assuming similar smoking trajectories across groups.

RESULTS

Youth were 45% Hispanic, 20% Asian, 20% white, 10% multiethnic, 2% black, and 1% other ethnicities. Higher average probability of smoking and steeper slopes of smoking trajectories were associated with poorer outcomes in multiple domains. Controlling for smoking trajectories, we observed the following disparities (vs. white youth; all p's < .05): black, Hispanic, and multiethnic youth reported lower academic performance; Asian, black, and multiethnic youth reported higher academic unpreparedness; Asian and multiethnic youth reported poorer mental health; Asian, Hispanic, and multiethnic youth reported poorer physical health; and Asian youth reported higher delinquency and poorer social functioning.

CONCLUSIONS

Statistically adjusting for similar smoking trajectories, racial/ethnic minority youth demonstrated poorer outcomes in multiple domains compared with white peers. Smoking may be a particularly robust marker for risk of negative outcomes in racial/ethnic minority youth. Screening for cigarette use and intervening on smoking and associated risk behaviors among minority youth may help reduce disparities in functioning.

Pathway of protection: Ethnic identity, self-esteem, and substance use among multiracial youth

Fifty percent of adolescents have tried an illicit drug and 70% have tried alcohol by the end of high school, with even higher rates among multiracial youth. Ethnic identity is a protective factor against substance use for minority groups. However, little is known about the mechanisms that facilitate its protective effects, and even less is known about this relationship for multiracial youth. The purpose of the present study was to examine the protective effect of ethnic identity on substance use and to determine whether this relationship operated indirectly through self-esteem, a strong predictor of substance use for among adolescent populations. Participants included 468 multiracial youth in grades six through 12 (53% female). The results found that ethnic identity was indeed related to substance use, partially through changes in self-esteem. Findings from this study contribute to our understanding and development of models of risk and protection for an understudied population.

Beyond experimentation: Five trajectories of cigarette smoking in a longitudinal sample of youth

The first goal of this study was to identify the most appropriate measure of cigarette smoking for identifying unique smoking trajectories among adolescents; the second goal was to describe the resulting trajectories and their characteristics. Using 15 annual waves of smoking data in the National Longitudinal Survey of Youth 1997 (NLSY97), we conducted an exploratory latent class growth analysis to determine the best of four outcome variables for yearly smoking (cigarettes per day on days smoked, days smoked per month, mean cigarettes per day, and total cigarettes per month) among individuals aged 12 to 30 (n = 8,791). Days smoked per month was the best outcome variable for identifying unique longitudinal trajectories of smoking and characteristics of these trajectories that could be used to target different types of smokers for prevention and cessation. Objective statistics were used to identify four trajectories in addition to never smokers (34.1%): experimenters (13.6%), quitters (8.1%), early established smokers (39.0%), and late escalators (5.2%). We identified a quitter and late escalator class not identified in the only other comparable latent class growth analysis. Logistic regressions were used to identify the characteristics of individuals in each trajectory. Compared with never smokers, all trajectories except late escalators were less likely to be black; experimenters were more likely to be out of school and unemployed and drink alcohol in adolescence; quitters were more likely to have a mother with a high school degree/GED or higher (versus none) and to use substances in adolescence and less likely to have ever married as a young adult; early established smokers were more likely to have a mother with a high school diploma or GED, be out of school and unemployed, not live with both parents, have used substances, be depressed, and have peers who smoked in adolescence and to have children as young adults and less likely to be Hispanic and to have ever married as young adults; and late escalators were more likely to be Hispanic, drink alcohol, and break rules in adolescence and less likely to have ever married as young adults. Because of the number of waves of data analyzed, this analysis provided a clearer temporal depiction of smoking behavior and more easily distinguishable smoking trajectories than previous analyses. Tobacco control interventions need to move beyond youth-focused approaches to reach all smokers.

Adolescent's respiratory sinus arrhythmia is associated with smoking rate five years later

INTRODUCTION

Vulnerability factors like respiratory sinus arrhythmia (RSA) may help identify adolescents at risk for nicotine dependence. We examined if resting RSA and the acute effects of smoking on RSA was associated with cigarette smoking five years later among adolescents at high risk for smoking escalation and nicotine dependence.

METHODS

Sixty-nine adolescents participated in a baseline laboratory session- RSA was collected before and after smoking a single cigarette ad libitum. Participants were then followed for five years.

RESULTS

Lower pre-smoke resting RSA was related to higher past month smoking rate five years later, even after controlling for baseline smoking rate and other relevant covariates including gender, race/ethnicity, age of initiated use, and frequency of exercise at baseline (p=0.018). Exploratory analyses suggested resting RSA is an independent predictor of increased cigarette rate beyond other baseline predictors.

CONCLUSIONS

Low resting RSA may be a vulnerability factor, helping to identify adolescents at risk for cigarette escalation.