Characteristics of Adolescents' and Young Adults' Exposure to and Engagement with Nicotine and Tobacco Product Content on Social Media.

To inform policy and messaging, this study examined characteristics of adolescents' and young adults' (AYAs') exposure to and engagement with nicotine and tobacco product (NTP) social media (SM) content. In this cross-sectional survey study, AYAs aged 13-26 (N=1,163) reported current NTP use, SM use frequency, and exposure to and engagement with SM content promoting and opposing NTP use (i.e. frequency, source[s], format[s], platform[s]). Participants who used NTPs (vs. did not use) were more likely to report having seen NTP content (p-values<.001). Prevalent sources were companies/brands (46.6%) and influencers (44.4%); prevalent formats were video (65.4%) and image (50.7%). Exposure to content promoting NTP use was prevalent on several popular platforms (e.g. TikTok, Instagram, Snapchat); exposure to content opposing NTP use was most prevalent on YouTube (75.8%). Among those reporting content engagement (i.e. liking, commenting on, or sharing NTP content; 34.6%), 57.2% engaged with influencer content. Participants reported engaging with content promoting and opposing NTP use on popular platforms (e.g. TikTok, Instagram, YouTube). Participants with (versus without) current NTP use were significantly more likely to use most SM platforms and to report NTP content exposure and engagement (p-values<.05). Results suggest that NTP education messaging and enforcement of platforms' content restrictions are needed.

Longitudinal Analysis of Associations Between Reasons for Electronic Cigarette Use and Change in Smoking Status Among Adults in the Population Assessment of Tobacco and Health Study.

INTRODUCTION: Electronic cigarette (ECIG) use and changes in cigarette smoking status may be influenced by self-reported reasons for using ECIGs. METHODS: We analyzed adult current and former cigarette smokers who were also current or former ECIG users at wave 1 (n = 3044) using wave 1 and wave 2 Population Assessment of Tobacco and Health Study data (2013-2015). Prevalence of reporting 13 reasons for ECIG use at wave 1 was examined and weighted logistic regressions were conducted predicting smoking status changes from wave 1 to wave 2. RESULTS: Reasons for ECIG use ranged from 18.1% (people in the media or public figures use them) to 82.5% (they might be less harmful to people around me than cigarettes). From wave 1 to wave 2, 27.2% of former smokers (n = 249) became current smokers and 11.6% of current smokers (n = 246) became former smokers. Among wave 1 former smokers, using ECIGs because of the availability of flavors (AOR = 0.57, 95% CI = 0.39-0.85) or because they don't smell (AOR = 0.64, 95% CI = 0.42-0.97) was associated with lower odds of relapse to smoking, but using ECIGs because using them helps people quit smoking (AOR = 1.55, 95% CI = 1.01-2.38) was associated with greater odds of relapse. Among wave 1 current smokers, using ECIGs because they can be used where smoking is not allowed (AOR = 0.56, 95% CI = 0.38-0.85) was associated with reduced odds of quitting cigarettes. CONCLUSIONS: Some reasons for ECIG use are associated with changes in self-reported smoking status. Researchers should examine ECIG user characteristics when assessing associations between ECIG use and smoking status transitions. IMPLICATIONS: Given that certain reasons for ECIG use, such as using ECIGs in locations are where smoking is not allowed, may inhibit smoking reduction, policies may be developed to prevent ECIG use in locations where smoking is banned. In addition, because certain reasons for ECIG use may aid in relapse prevention, such as availability of desired flavors, efforts should be made to identify ECIG device characteristics that are appealing to smokers but not youth or nontobacco users. These results provide support for future research on reasons for ECIG use to inform regulatory policies.

How Does Smoking and Nicotine Dependence Change After Onset of Vaping? A Retrospective Analysis of Dual Users.

INTRODUCTION: Although some smokers switch to exclusive use of electronic cigarettes (e-cigarettes), others become dual users of combustible cigarettes and e-cigarettes. Little is known about how the onset of vaping affects the use of and dependence on combustible cigarettes or total nicotine use and dependence, which may influence health-related and cessation outcomes. Using self-report data of current combustible and e-cigarette use and retrospective recall of pre-vaping smoking in a sample of dual users, the aims of this study were (1) to compare pre- and post-vaping number of cigarettes per day and combustible cigarette dependence; (2) to compare pre- and post-vaping total nicotine use frequency (number of vaping sessions and cigarettes smoked per day), and total nicotine dependence; and (3) to examine predictors of nicotine dependence. METHODS: We used baseline data from a smoking cessation trial with 2896 dual users. Nicotine use frequency and the Heaviness of Smoking Index were used as measures of nicotine use and dependence, respectively. RESULTS: Participants decreased cigarettes/day from pre- (M = 19.24, SD = 9.01) to post-vaping (M = 11.15, SD = 8.02, p < .0001) and combustible cigarette dependence declined from pre- (M = 3.55, SD = 1.51) to post-vaping (M = 2.11, SD = 1.60, p < .0001). Total daily nicotine use frequency increased after initiating vaping (M = 19.25, SD = 9.01 vs. M = 29.46, SD = 8.61; p < .0001), as did total nicotine dependence (M = 3.55, SD = 1.51 vs. M = 4.68, SD = 1.38; p < .0001). Hierarchical regression analyses indicated that variables associated with greater overall nicotine dependence included: younger age, lower education, more years smoking, higher pre-vaping nicotine dependence, using e-cigarettes more days per month, more puffs per vaping session, higher e-liquid nicotine concentration, and longer vaping history. CONCLUSIONS: Dual use leads to a reduction in the number of combustible cigarettes, but total nicotine use and dependence increases. IMPLICATIONS: In dual users, a reduction in smoking following onset of vaping may offer some harm reduction via reduction in cigarette intake. However, the increase in total nicotine use and dependence could affect the ability to quit either or both products.

Investigating the role of expectancy in caffeine withdrawal using the balanced placebo design.

OBJECTIVE: This study investigated psychological influences on drug withdrawal symptomatology using a caffeine-based model. METHODS: Using the 2 × 2 balanced placebo design caffeine dose (given caffeinated vs decaffeinated coffee) was crossed with dose expectancy (told caffeine vs. decaf) among 87 (16-hr abstinent) regular coffee consumers in a 2-day study. RESULTS: There were effects of expectancy and pharmacology that differed depending on the measure. Those told decaf reported greater caffeine cravings than those told caffeine 45 min and 8 hr postmanipulation. There were no expectancy effects on withdrawal symptoms or cognitive performance. There were pharmacological effects on all measures. Those given decaf reported greater withdrawal symptoms and showed poorer cognitive performance 45 min and 8 hr postmanipulation, with effects for headache and flu-like symptoms first emerging 8 hr postmanipulation (i.e., 24 hr abstinence in given decaf conditions). Caffeine readministration alleviated all withdrawal symptoms and cognitive decrements within 45 min. No drug by expectancy interactions were observed. CONCLUSIONS: These findings confirm a strong pharmacological basis for caffeine withdrawal and an important role of cognition in drug craving. Future research should investigate the role of expectancy in drug withdrawal and craving and the potential use of expectancy manipulations in symptom prevention and management.

Basic Science and Public Policy: Informed Regulation for Nicotine and Tobacco Products.

Introduction: Scientific discoveries over the past few decades have provided significant insight into the abuse liability and negative health consequences associated with tobacco and nicotine-containing products. While many of these advances have led to the development of policies and laws that regulate access to and formulations of these products, further research is critical to guide future regulatory efforts, especially as novel nicotine-containing products are introduced and selectively marketed to vulnerable populations. Discussion: In this narrative review, we provide an overview of the scientific findings that have impacted regulatory policy and discuss considerations for further translation of science into policy decisions. We propose that open, bidirectional communication between scientists and policy makers is essential to develop transformative preventive- and intervention-focused policies and programs to reduce appeal, abuse liability, and toxicity of the products. Conclusions: Through these types of interactions, collaborative efforts to inform and modify policy have the potential to significantly decrease the use of tobacco and alternative nicotine products and thus enhance health outcomes for individuals. Implications: This work addresses current topics in the nicotine and tobacco research field to emphasize the importance of basic science research and provide examples of how it can be utilized to inform public policy. In addition to relaying current thoughts on the topic from experts in the field, the article encourages continued efforts and communication between basic scientists and policy officials.

Patterns of youth tobacco and polytobacco usage: The shift to alternative tobacco products.

BACKGROUND: Despite significant declines in youth cigarette smoking, overall tobacco usage remains over 20% as non-cigarette tobacco product usage is increasingly common and polytobacco use (using 1+ tobacco product) remains steady. OBJECTIVES: The present study was designed to identify patterns of youth tobacco use and examine associations with sociodemographic characteristics and tobacco dependence. METHODS: The current analysis uses Latent Class Analysis (LCA) to examine the 6,958 tobacco users (n = 2,738 female) in the National Youth Tobacco Survey (2012 and 2013). We used as indicators past month use of tobacco products (cigarettes, cigars, smokeless tobacco, e-cigarettes, hookah, snus, pipes, bidis, and kreteks) and regressed resulting classes on sociodemographic characteristics and tobacco dependence. RESULTS: Nine classes emerged: cigarette smokers (33.4% of sample, also included small probabilities for use of cigars and e-cigarettes), cigar smokers (16.8%, nearly exclusive), smokeless tobacco users (12.3%, also included small probabilities for cigarettes, cigars, snus), hookah smokers (11.8%), tobacco smokers/chewers (10.7%, variety of primarily traditional tobacco products), tobacco/hookah smokers (7.2%), tobacco/snus/e-cig users (3.3%), e-cigarette users (2.9%,), and polytobacco users (1.7%, high probabilities for all products). Compared to cigarette smokers, tobacco/hookah smokers and hookah smokers were more likely to report Hispanic ethnicity. Polytobacco users were more likely to report dependence (AOR:2.77, 95% CI:[1.49-5.18]), whereas e-cigarette users were less likely (AOR:0.49, 95% CI:[0.24-0.97]). CONCLUSION: Findings are consistent with other research demonstrating shifts in adolescent tobacco product usage towards non-cigarette tobacco products. Continuous monitoring of these patterns is needed to help predict if this shift will ultimately result in improved public health.

An exploration of alcohol use severity and route of drug administration among persons that use heroin and cocaine.

BACKGROUND: Alcohol use is prevalent among populations of persons that use illicit drugs. Problematic alcohol use among persons that use heroin and cocaine has been associated with poor treatment adherence, abstinence maintenance, and mental health concerns. Fully exploring how alcohol use severity interacts with route of administration (ROA) may be of notable importance in development of treatment protocols for persons that use heroin and cocaine. METHODS: Data from a neurological and sociobehavioral assessment of risk factors among injection and noninjection drug users known as the NEURO-HIV Epidemiologic Study was used in the analyses. Participants (N = 551) included those who reported their level of past-30-day alcohol use and past-6-month heroin and cocaine use. RESULTS: Multiple logistic regression analyses found that both problematic and moderate alcohol users were significantly less likely than abstainers to report injecting heroin and cocaine. Both problematic and moderate alcohol users were significantly more likely than abstainers to snort substances. CONCLUSIONS: Alcohol use may play a role in promoting or impeding the use of substances through certain ROAs. Treatment protocols that transition persons that use injection heroin and cocaine to noninjection use of these substances may be used in conjunction with treatments that reduce alcohol consumption as a means to reduce noninjection drug use.

E-cigarette use in adults: a qualitative study of users' perceptions and future use intentions.

BACKGROUND: There has been an exponential increase in the prevalence of e-cigarette use, particularly among youth. However, adult use is also rising, and there have been relatively few qualitative studies with adult users to understand their reasons for use and future use intentions. Such information is needed to inform both prevention and cessation approaches. METHOD: Thirty-one e-cigarette users participated in one of several focus groups assessing the appeal of e-cigarettes as well as comparisons to combustible cigarettes and approved smoking cessation aids. We also obtained perspectives on future use intentions and interest in e-cigarette cessation interventions. Verbatim transcripts were analyzed using the constant comparative method. RESULTS: Participants reported several aspects of e-cigarette appeal as compared to approved cessation treatment options. These included similarities to combustible cigarettes, fewer side effects, and control of e-cigarettes to suit personal preferences. Participants were split on whether they preferred flavors that mimicked or contrasted with their combustible cigarettes (i.e., tobacco vs. alternative flavors, such as candy). Some participants who were unmotivated to quit smoking reported an unanticipated disinterest in continuing use of combustible cigarettes shortly after initiating e-cigarettes. Despite strong interest in reducing nicotine dosage, the majority did not intend to fully discontinue e-cigarettes. CONCLUSIONS: Understanding e-cigarette users' perspectives can inform policy and treatment development. Regulatory and policy initiatives will need to balance the appealing characteristics of e-cigarettes with the potential for negative public health outcomes.

Expectancies for cigarettes, e-cigarettes, and nicotine replacement therapies among e-cigarette users (aka vapers).

INTRODUCTION: Use of e-cigarettes has been increasing exponentially, with the primary motivation reported as smoking cessation. To understand why smokers choose e-cigarettes as an alternative to cigarettes, as well as to US Food and Drug Administration (FDA)--approved nicotine replacement therapies (NRT), we compared outcome expectancies (beliefs about the results of drug use) for the three nicotine delivery systems among vapers, i.e., e-cigarette users, who were former smokers. METHODS: Vapers (N = 1,434) completed an online survey assessing 14 expectancy domains as well as perceived cost and convenience. We focused on comparisons between e-cigarettes and cigarettes to determine the attraction of e-cigarettes as a smoking alternative and between e-cigarettes and NRT to determine perceived advantages of e-cigarettes over FDA-approved pharmacotherapy. RESULTS: Participants believed that e-cigarettes, in comparison to conventional cigarettes, had fewer health risks; caused less craving, withdrawal, addiction, and negative physical feelings; tasted better; and were more satisfying. In contrast, conventional cigarettes were perceived as better than e-cigarettes for reducing negative affect, controlling weight, providing stimulation, and reducing stress. E-cigarettes, compared to NRT, were perceived to be less risky, cost less, cause fewer negative physical feelings, taste better, provide more satisfaction, and be better at reducing craving, negative affect, and stress. Moderator analyses indicated history with ad libitum forms of NRT was associated with less positive NRT expectancies. CONCLUSIONS: The degree to which expectancies for e-cigarettes differed from expectancies for either tobacco cigarettes or NRT offers insight into the motivation of e-cigarette users and provides guidance for public health and clinical interventions to encourage smoking-related behavior change.

Electronic cigarettes in adults in outpatient substance use treatment: Awareness, perceptions, use, and reasons for use.

BACKGROUND AND OBJECTIVES: Most studies on e-cigarettes have come from population-based surveys. The current research aimed to provide initial data on e-cigarette awareness, perceptions, use, and reasons for use among adults seeking substance use treatment. METHODS: A survey was conducted among 198 participants ≥18 years old in a community-based outpatient substance use treatment program. RESULTS: Of the 198 participants, 69% currently smoked cigarettes, 92% were aware of e-cigarettes, and 58% had ever used e-cigarettes. The proportion of the number of participants who had ever used e-cigarettes to the number who currently smoked (89.7%) appeared higher than the corresponding proportion in the 2012-13 National Adult Tobacco Survey (78.3%). Almost half of the sample who reported ever using e-cigarettes endorsed quitting or reducing smoking as a reason for use, and 32% endorsed reasons for use relating to curiosity/experimentation. A greater likelihood of e-cigarette ever-use was significantly associated with younger age (adjusted odds ratio [AOR] = 0.94, 95%confidence interval [CI] = 0.90, 0.98) and perceptions related to using e-cigarettes in public places where smoking cigarettes is not allowed (AOR = 2.96, 95%CI = 1.18, 7.42) but was not associated with primary drug of choice. DISCUSSION AND CONCLUSIONS: E-cigarette use in adults seeking substance use treatment appears higher than it is in the US general population of smokers. The high frequency of use may be due to curiosity/experimentation or attempts to quit or reduce smoking. SCIENTIFIC SIGNIFICANCE: Future research may consider how e-cigarettes interact with other substance use and affect high rates of nicotine and tobacco use in this population.

Pain Symptoms Associated with Opioid Use among Vulnerable Persons with HIV: An exploratory study with implications for palliative care and opioid abuse prevention.

Current or former injection drug users with human immunodeficiency virus (HIV) are at high risk for pain, which adversely affects their quality of life and may increase their risk for illicit drug use or relapse. We explored associations between pain symptoms and substance use among injection-drug-using study participants with HIV who had histories of heroin use. Using generalized estimating equations and controlling for prior substance use, we found that pain in each six-month period was associated with the use of heroin and prescription opioids, but not the use of nonopioid drugs or alcohol. Routine clinical assessment and improved management of pain symptoms may be needed for persons with HIV and a history of injection drug use, particularly those with chronic pain, for whom there is increased risk for heroin use.

Cigarette smoking and drug use among a nationally representative sample of HIV-positive individuals.

BACKGROUND AND OBJECTIVES: Among HIV-positive populations, the prevalence of cigarette smoking remains disproportionately high and is associated with significant morbidity and mortality. Little is known about this topic among HIV-positive persons in the general population. METHODS: Data came from the 2005 to 2011 National Survey on Drug Use and Health (NSDUH) public use data files. Unadjusted and adjusted multinomial logistic regression analyses explored the associations between socio-demographic, drug and alcohol use, and drug and/or alcohol treatment characteristics with smoking status among HIV-positive individuals (n = 349). RESULTS: More than 40% of the sample was current smokers. In adjusted analyses, females (aRRR = .11, 95% CI = .03-.41) and participants who had never been married (aRRR = .19, 95% CI = .05-.58), were more likely to be former smokers than never smokers. Females (aRRR = .37, 95% CI = .14-.96) and individuals older than age 35 (aRRR = .37, 95% CI = .16-.89) were less likely to be current smokers than never smokers. Conversely, previously married persons (aRRR = 5.72, 95% CI = 1.40-23.31), participants reporting binge drinking (aRRR = 5.96, 95% CI = 2.27-15.64), and lifetime drug or alcohol treatment (aRRR = 5.12, 95% CI = 2.09-12.55) were more likely to be current smokers than never smokers. CONCLUSIONS: Findings help confirm the high prevalence of smoking among HIV-positive persons suggesting the need for integrated substance use and smoking cessation treatment among HIV-positives. SCIENTIFIC SIGNIFICANCE: The present findings have implications for the development and implementation of targeted smoking cessation programs for HIV-positive smokers.

The influence of religious attendance on smoking.

UNLABELLED: Generalized linear models were used to assess the relationship between religious attendance and lifetime smoking status among middle-aged adults (n = 666) sampled from waves three (1993 to 1996) and four (2004 to 2005) of the Baltimore Epidemiologic Catchment Area (ECA) study. Religious attendance once per week or greater as compared to never was inversely associated with smoking status. Future research should explore potential mediating factors of the association between religious attendance and smoking among middle-aged adults in order to gain a greater understanding of the mechanisms underlying this relationship. FUNDING: NIMH grant DA026652; NIDA grant T32DA007292.

Causal inference in tobacco research: a public health challenge.

Causal inference represents a rapidly expanding interdisciplinary subfield that involves various assumptions, study designs, and estimation strategies, allowing researchers to establish causal relationships from both clinical trials and observational data. In tobacco research, numerous studies address causal questions, including the contentious issue of whether vaping in nonsmoking youth leads to smoking initiation, known as the "gateway effect." Determining the effectiveness and safety of many health interventions will continue to rely on observational [mainly longitudinal] data because randomized trials are not always feasible, ethical, or timely. Therefore, review articles that are synthesizing evidence on the gateway effects of electronic nicotine delivery systems [ENDS] on subsequent cigarette smoking must also consider observational studies as first-rate evidence that can help bring together the polarized tobacco research community and help better understand the "gateway effect." In addition, this will help ongoing efforts to rigorously prevent ENDS use by youth while expanding the cessation potential of ENDS among adult established smokers who are unwilling to quit otherwise. In this commentary, we discuss causal inference tobacco research as one of the public health challenges and provide some recommendations/implications.

Measuring vaping-related expectancies in young adults: Psychometric evaluation of the Electronic Nicotine Vaping Outcomes (ENVO) scale.

OBJECTIVE: Electronic cigarettes are the most commonly used tobacco products by young adults. Measures of beliefs about outcomes of use (i.e., expectancies) can be helpful in predicting use, as well as informing and evaluating interventions to impact use. METHODS: We surveyed young adult students (N = 2296, Mean age=20.0, SD=1.8, 64 % female, 34 % White) from a community college, a historically black university, and a state university. Students answered ENDS expectancy items derived from focus groups and expert panel refinement using Delphi methods. Factor Analysis and Item Response Theory (IRT) methods were used to understand relevant factors and identify useful items. RESULTS: A 5-factor solution [Positive Reinforcement (consists of Stimulation, Sensorimotor, and Taste subthemes, α = .92), Negative Consequences (Health Risks and Stigma, α = .94), Negative Affect Reduction (α = .95), Weight Control (α = .92), and Addiction (α = .87)] fit the data well (CFI=0.95; TLI=0.94; RMSEA=0.05) and was invariant across subgroups. Factors were significantly correlated with relevant vaping measures, including vaping susceptibility and lifetime vaping. Hierarchical linear regression demonstrated factors were significant predictors of lifetime vaping after controlling for demographics, vaping ad exposure, and peer/family vaping. IRT analyses indicated that individual items tended to be related to their underlying constructs (a parameters ranged from 1.26 to 3.18) and covered a relatively wide range of the expectancies continuum (b parameters ranged from -0.72 to 2.47). CONCLUSIONS: A novel ENDS expectancy measure appears to be a reliable measure for young adults with promising results in the domains of concurrent validity, incremental validity, and IRT characteristics. This tool may be helpful in predicting use and informing future interventions. IMPLICATIONS: Findings provide support for the future development of computerized adaptive testing of vaping beliefs. Expectancies appear to play a role in vaping similar to smoking and other substance use. Public health messaging should target expectancies to modify young adult vaping behavior.

Neighborhood disorder and juvenile drug arrests: a preliminary investigation using the NIfETy instrument.

BACKGROUND: Disordered neighborhood environments are associated with crime, drug use, and poor health outcomes. However, research utilizing objective instruments to characterize the neighborhood environment is lacking. OBJECTIVES: This investigation examines the relationship between objective measures of neighborhood disorder and juvenile drug arrests (JDAs) in an urban locale. METHODS: The neighborhood disorder scale was developed using indicators from the Neighborhood Inventory for Environmental Typology (NIfETy) instrument; a valid and reliable tool that assesses physical and social disorder. Data on 3146 JDAs from 2006 were obtained from the police department. RESULTS: Negative binomial regression models revealed a significant association between neighborhood disorder and the count of JDAs in the neighborhood (ß == .34, p < .001). The relationship between neighborhood disorder and JDAs remained significant after adjusting for percent African-Americans in the neighborhood (ß == .24, p < .001). CONCLUSIONS: This preliminary investigation identified a positive and statistically significant relationship between an objective measure of neighborhood disorder and JDAs. Future investigations should examine strategies to reduce drug-related crime by addressing the larger neighborhood and social context in which drug involvement and crime occurs.

Emotion dysregulation, transdiagnostic vulnerabilities, and e-cigarette expectancies in a young adult sample.

OBJECTIVE: Use of e-cigarettes is more common among youth with psychological distress. Negative affect reduction outcome expectancies (beliefs about ability of a product to reduce unpleasant emotional states) and emotional transdiagnostic vulnerabilities (maladaptive responses to emotional states common to multiple forms of emotional psychopathology) are both positively related to tobacco susceptibility and use. However, it is unclear if expectancies mediate the effects between emotional issues and use. METHOD: College students aged 18 to 24 (N = 216; 79.6% female; 36.6% African American) completed an online survey with measures on e-cigarette negative affect reduction outcome expectancies (ENAROE), e-cigarette use, and the following emotional transdiagnostic vulnerabilities (ETV): difficulties in emotion regulation, distress tolerance (DT), positive/negative urgency, and positive/negative affect. RESULTS: In individual predictor path analysis models, ENAROE mediated the relationship between ETVs and e-cigarette use. Expectancies (ENAROE) mediated 47.3% of the total relationship between positive urgency and use. Significant effects were found for a comprehensive model, in which negative urgency was related to higher ENAROE (b = 0.47, 95% BCCI [0.04, 0.96]), controlling for all other transdiagnostic vulnerabilities. Higher positive urgency was related to an increased likelihood of current use. CONCLUSIONS: This study provides a novel examination of expectancies as a potential mediator for current e-cigarette use via emotional vulnerabilities. Negative Affect Reduction outcome expectancies mediated the relationship between vulnerabilities and e-cigarette use, indicating that the association between positive urgency and e-cigarette use may be explained partially though emotional expectancies. Thus, expectancies are important targets for prevention and further ETV research.

Identifying prospective subpopulations of combustible and electronic cigarette dual users in the United States via finite mixture modeling.

AIMS: To identify subpopulations of dual users of combustible and electronic cigarettes using current smoking and vaping behaviors. DESIGN: Secondary analysis of baseline data from a randomized controlled trial testing a smoking cessation intervention for dual users. Finite mixture modeling of frequency, quantity, and dependence on combustible and electronic cigarettes was used to identify classes. Demographics and additional smoking and vaping variables were used to further characterize the classes. SETTING: United States. PARTICIPANTS: A total of 2896 adults who smoked weekly for the past year and vaped weekly for the past month. MEASUREMENTS: Self-report baseline measures assessed demographics and smoking and vaping behaviors and characteristics including days of use per week, frequency of use within a day, time to first use after waking, urges to smoke, smoking cessation motivation, self-efficacy to abstain from smoking, months since vaping initiation, reasons for initiating and maintaining vaping, and future plans to stop vaping. FINDINGS: Eight probabilistic classes were identified and well-defined (relative entropy = 0.95, Lo-Mendell-Rubin adjusted likelihood ratio test P < 0.0001; class probabilities 0.89-0.97). In general, classes crossed two levels of smoking with four levels of vaping. The largest class (31%) had relatively high levels of smoking (72% daily, 56% 11+ cigarettes per day [CPD], 96% within 30 minutes of waking) and vaping (74% daily, 100% 20+ electronic-CPD, 74% <30 minutes). The next largest class (27%) had relatively high levels of vaping (93% daily, 100% 20+ electronic-CPD, 82% <30 minutes) and very low levels of smoking (28% daily, 12% 11+ CPD, 0% <30 minutes). The six smaller classes (3%-13%) also had distinct smoking and vaping behaviors. All eight classes exhibited distinguishing characteristics beyond current smoking and vaping behaviors. CONCLUSIONS: Dual users of combustible and electronic cigarettes are not a homogeneous population, having eight well-defined prospective subpopulations.