Respiratory symptoms and outcomes among cigar smokers: findings from the Population Assessment of Tobacco and Health (PATH) study waves 2-5 (2014-2019).

BACKGROUND: The mechanisms by which cigarette smoking increases the risk of respiratory disease have been studied. However, less is known about risks of respiratory symptoms and outcomes associated with smoking cigars, and risks by cigar types have not been previously explored. The aim of this study was to examine associations between cigar use, including traditional cigars, cigarillos, filtered cigars, and dual cigar and cigarette use, and functionally important respiratory symptoms (FIRS), lifetime asthma diagnosis, uncontrolled asthma, and new cases of FIRS. METHODS: Data from Waves 2-5 (2014-19) of the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative longitudinal study, were analyzed in two ways. For cross-sectional analysis, the analytic sample included adults 18 and older at each wave, resulting in 44,040 observations. Separately, longitudinal analyses were assessed among adults 18 and older at Wave 2, resulting in 7,930 individuals. Both analyses excluded adults with chronic obstructive pulmonary disease (COPD) or non-asthma respiratory disease. RESULTS: Current established cigarillo smokers had higher odds of having FIRS (Adjusted odds ratio (AOR): 1.72; 95% CI: 1.08, 2.74) compared to never smokers of cigarillos and cigarettes, after adjusting for covariates. Current established filtered cigar smokers had higher odds of asthma diagnosis (AOR: 1.35; 95% CI: 1.10, 1.66) while current established dual smokers of filtered cigars and cigarettes had higher odds of uncontrolled asthma (AOR: 5.13; 95% CI: 1.75, 15.02) compared to never smokers of filtered cigars or cigarettes. Both current established cigar smokers and current established dual smokers of cigarettes and cigars had higher odds of new FIRS compared to never cigar or cigarette smokers (AORs: 1.62; 95% CI: 1.02, 2.60 for exclusive cigars and 2.55; 95% CI 1.57, 4.14 for dual smokers). CONCLUSIONS: This study provides evidence that cigar smokers or dual smokers of cigars and cigarettes have greater odds of FIRS, asthma, and uncontrolled asthma and that new incidence of FIRS is higher among any cigar smokers compared to never cigar or cigarette smokers. Understanding health impacts associated with cigar use provides information for supporting policy development, as well as for designing clinical interventions focused on smoking cessation for cigars.

Divergence in Cigarette Discontinuation Rates by Use of Electronic Nicotine Delivery Systems (ENDS): Longitudinal Findings From the United States PATH Study Waves 1-6.

INTRODUCTION: We compare real-world trends in population-level cigarette discontinuation rates among adults (ages ≥21) who smoked cigarettes, by electronic nicotine delivery systems (ENDS) use. AIMS AND METHODS: U.S nationally representative data from adults in the Population Assessment of Tobacco and Health (PATH) Study (2013/14-2021, Waves 1-6) who smoked cigarettes in the past 30 days (P30D) were analyzed (n = 13 640). The exposure was P30D ENDS use. The outcome was P30D cigarette discontinuation at biennial follow-up. Weighted trend analyses were conducted to test for differences in cigarette discontinuation trends by ENDS use. RESULTS: Between 2013/14 and 2015/16, cigarette discontinuation rates were both 16% for those who used ENDS and for those who did not; between 2018/19 and 2021, rates were ~30% for those who used ENDS and ~20% for those who did not; the time by ENDS use interaction was significant. CONCLUSIONS: The relationship between adults' ENDS use and cigarette discontinuation in the context of an expanded ENDS marketplace, new tobacco regulatory actions, and COVID-19 differs from the relationship in earlier years. IMPLICATIONS: It is important for public health decisions to be informed by research based on the contemporary ENDS marketplace and circumstances.

2020 design and methods of the Population Assessment of Tobacco and Health (PATH) study during the COVID-19 pandemic.

The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative, longitudinal study of the US population on tobacco use and its effects on health, collecting data annually since 2013. The COVID-19 pandemic interrupted in-person survey data collections around the world. In the USA, this included a PATH Study data collection focused on youth (13-17) and young adults (18-19) as well as other US surveys on tobacco use. Given that it was necessary to pause data collection and considering that tobacco-use behaviours could be expected to change along with pandemic-related changes in the social environment, the original design for the 2020 PATH Study data collection for youth and young adults was modified. Also, the PATH Study Adult Telephone Survey was developed to address the need for adult tobacco use monitoring in this unprecedented time. This article describes the modifications made to the 2020 PATH Study design and protocol to provide nationally representative data for youth and adults after the onset of the COVID-19 pandemic as well as the implications of these modifications for researchers.

Predictors of E-cigarette and Cigarette Use Trajectory Classes from Early Adolescence to Emerging Adulthood Across Four Years (2013-2017) of the PATH Study.

INTRODUCTION: This study examines predictors of trajectories of cigarette and e-cigarette use among a cohort of US adolescents transitioning into young adulthood. Comparing trajectories of each tobacco product is important to determine if different intervention targets are needed to prevent progression to daily use. METHODS: Latent trajectory class analyses identified cigarette and e-cigarette use (never, ever excluding past 12-month, past 12-month (excluding past 30-day (P30D)), P30D 1-5 days, P30D 6+ days) trajectory classes, separately, among US youth (12-17; N = 10,086) using the first 4 waves (2013-2017) of data from the nationally representative PATH Study. Weighted descriptive analyses described the class characteristics. Weighted multinomial logistic regression analyses examined demographic, psychosocial, and behavioral predictors of class membership. RESULTS: Younger adolescents 12-15 years had lower tobacco use compared to 16-17 year olds and less stable classes. In the 16-17 year group, there were five unique trajectories of cigarette smoking, including a Persistent High Frequency class. Four e-cigarette use trajectories were identified; but not a persistent use class. Shared predictors of class membership for cigarettes and e-cigarettes included mental health problems, other tobacco use, marijuana use, and poorer academic achievement. Male sex and household tobacco use were unique e-cigarette trajectory class predictors. CONCLUSIONS: There was no evidence that initiation with e-cigarettes as the first product tried was associated with cigarette progression (nor cigarettes as first product and e-cigarette progression). Interventions should focus on well-established risk factors such as mental health and other substance use to prevent progression of use for both tobacco products. IMPLICATIONS: Using nationally representative data and definitions of use that take into account frequency and recency of use, longitudinal 4-year trajectories of e-cigarette and cigarette use among US adolescents transitioning into young adulthood were identified. Results among 16-17-year olds revealed a class of persistent high frequency cigarette smoking that was not identified for e-cigarette use. Cigarette use progression was not associated with e-cigarettes as the first product tried. Risk factors for progression of use of both products included mental health and other substance use, which are important prevention targets for both tobacco products.

Variability in Urinary Nicotine Exposure Biomarker Levels Between Waves 1 (2013-2014) and 2 (2014-2015) in the Population Assessment of Tobacco and Health Study.

INTRODUCTION: To date, no studies have evaluated the consistency of biomarker levels in people who smoke over a long-time period in real-world conditions with a large number of subjects and included use behavior and measures of nicotine metabolism. We evaluated the variability of biomarkers of nicotine exposure over approximately a 1-year period in people who exclusively smoke cigarettes, including intensity and recency of use and brand switching to assess impact on understanding associations with product characteristics. AIMS AND METHODS: Multivariate regression analysis of longitudinal repeated measures of urinary biomarkers of nicotine exposure from 916 adults in the Population Assessment of Tobacco and Health (PATH) Study with demographic characteristics and use behavior variables. Intraclass correlation coefficients (ICCs) were calculated to examine individual variation of nicotine biomarkers and the uncertainty of repeat measures at two time points (Waves 1 and 2). RESULTS: Age, race, and urinary creatinine were significant covariates of urinary cotinine. When including use behavior, recency, and intensity of use were highly significant and variance decreased to a higher extent between than within subjects. The ICC for urinary cotinine decreased from 0.7530 with no use behavior variables in the model to 0.5763 when included. Similar results were found for total nicotine equivalents. CONCLUSIONS: Urinary nicotine biomarkers in the PATH Study showed good consistency between Waves 1 and 2. Use behavior measures such as time since last smoked a cigarette and number of cigarettes smoked in the past 30 days are important to include when assessing factors that may influence biomarker concentrations. IMPLICATIONS: The results of this study show that the consistency of the nicotine biomarkers cotinine and total nicotine equivalents in spot urine samples from Waves 1 to 2 of the PATH Study is high enough that these data are useful to evaluate the association of cigarette characteristics with biomarkers of exposure under real-world use conditions.

RETRACTED: Changes in Tobacco Dependence and Association With Onset and Progression of Use by Product Type From Wave 1 to Wave 3 of the Population Assessment of Tobacco and Health (PATH) Study.

INTRODUCTION: This study examined trajectories of tobacco dependence (TD) in relation to changes in tobacco product use and explored the effects of product-specific adding, switching, or discontinued use on dependence over time. AIMS AND METHODS: Data were analyzed from the first three waves of the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States. Data included 9556 Wave 1 (2013/2014) adult current established tobacco users who completed all three interviews and had established use at ≥2 assessments. Groups included cigarettes-only users, e-cigarettes-only users, cigars-only users, hookah-only users, any smokeless-only users, cigarette + e-cigarette dual users, and multiple product users. A validated 16-item scale assessed TD across product users. RESULTS: Wave 1 e-cigarette-only users' who maintained exclusive e-cigarette use increased levels of TD through Wave 3 as did those who added or switched to another product. Wave 1 multiple product users' TD decreased across waves. TD for all other Wave 1 user groups remained about the same. For Wave 1 cigarette-only smokers, switching to another product or moving to a pattern of no established use was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all other product users. CONCLUSIONS: Except for Wave 1 e-cigarette-only users, TD among US tobacco product users was stable over time, with daily users less likely to vary from baseline. IMPLICATIONS: The level of TD among most US tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users, including those maintaining exclusive e-cigarette use, experienced increasing levels of TD over time, perhaps because of increases in quantity or frequency of their e-cigarette product use or increasing efficiency of nicotine delivery over time.

Changes in Tobacco Dependence and Association With Onset and Progression of Use by Product Type From Waves 1 to 3 of the Population Assessment of Tobacco and Health (PATH) Study.

INTRODUCTION: This study examined trajectories of tobacco dependence (TD) in relationship to changes in tobacco product use, and explored the effects of product-specific adding, switching, or discontinued use on dependence over time. AIMS AND METHODS: Data were analyzed from the first three waves from the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States. Data included 9556 wave 1 (2013-2014) adult current established tobacco users aged 18 or older who completed all three interviews and had established use at ≥2 assessments. Mutually exclusive groups included: users of cigarettes only, e-cigarettes only, cigars only, hookah only, any smokeless only, cigarette + e-cigarette dual users, and other multiple product users. A validated 16-item scale assessed TD across product users. RESULTS: People who used e-cigarettes exclusively at wave 1 had small increases in TD through wave 3. Wave 1 multiple product users' TD decreased across waves. TD for all other wave 1 user groups remained about the same. For wave 1 cigarette only smokers, switching to another product was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all product users. CONCLUSIONS: Except for wave 1 e-cigarette only users (who experienced small increases in TD), TD among U.S. tobacco product users was stable over time, with daily users less likely to vary from baseline. IMPLICATIONS: The level of TD among most U.S. tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users experienced small increases in levels of TD over time, perhaps due to increases in quantity or frequency of their e-cigarette use or increasing efficiency of nicotine delivery over time.

Patterns of Premium and Nonpremium Cigar Use in the United States: Findings from Wave 6 (2021) of the Population Assessment of Tobacco and Health Study.

INTRODUCTION: Understanding the characteristics of premium cigar use patterns is essential for minimizing public health harms. Typically, premium cigars are handmade, larger, more expensive, and without the characterizing flavors that are present in other cigar types: Nonpremium traditional cigars, cigarillos, and filtered cigars. AIMS AND METHODS: Self-reported brand and price data were used from Wave 6 of the Population Assessment of Tobacco and Health (PATH) Study to define and estimate premium versus nonpremium cigar use among U.S. adults, as well as to explore cigar smoking patterns, purchasing behavior, and reasons for use by cigar type. RESULTS: In 2021, 0.9% (95% CI = 0.7-1.0) of adults were premium cigar users, compared to 0.4% of nonpremium traditional cigar users (95% CI = 0.3-0.5), 1.1% of cigarillo users (95% CI = 1.0-1.2), and 0.6% filtered cigar users (95% CI = 0.5-0.7). Premium cigar users were overwhelmingly male (97.7%), and 35.8% were aged ≥55 years. The average premium cigar price/stick was $8.67, $5.50-7.00 more than other cigar types. Compared to other cigar types, significantly fewer premium cigar users had a regular brand with a flavor other than tobacco (~15% vs. 38%-53%). Though flavors remained the top reason for premium cigar use, they were less likely to endorse flavors as a reason for use than other cigar users (~40% vs. 68-74%). Premium cigar users had a lower prevalence (aRR: 0.37, 95% CI = 0.25-0.55) of dual use of cigars and cigarettes. CONCLUSIONS: Although <1% of U.S. adults use premium cigars, their use and purchasing characteristics continue to differ from other cigar types, highlighting the importance of capturing data specific to premium cigar use. IMPLICATIONS: This manuscript extends previous research from the National Academies of Science, Engineering, and Medicine report, "Premium cigars: Patterns of use, marketing, and health effects" by utilizing the most recent PATH Study data (Wave 6) to examine patterns of cigar use, including purchasing behavior and reasons for use, by cigar type (eg, premium traditional cigars, nonpremium traditional cigars, cigarillos, and filtered cigars). The findings support continued research on patterns of premium cigar use, which differ from use patterns of other cigar types.

Indicators of Tobacco Dependence Among Youth: Findings From Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health Study.

BACKGROUND: Prior work established a measure of tobacco dependence (TD) among adults that can be used to compare TD across different tobacco products. We extend this approach to develop a common, cross-product metric for TD among youth. METHODS: One thousand one hundred and forty-eight youth aged 12-17 who used a tobacco product in the past 30 days were identified from 13 651 youth respondents in Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study. FINDINGS: Analyses confirmed a single primary latent construct underlying responses to TD indicators for all mutually exclusive tobacco product user groups. Differential Item Functioning analyses supported the use of 8 of 10 TD indicators for comparisons across groups. With TD levels anchored at 0.0 (standard deviation [SD] = 1.0) among cigarette only (n = 265) use group, mean TD scores were more than a full SD lower for e-cigarette only (n = 150) use group (mean = -1.09; SD = 0.64). Other single product use group (cigar, hookah, pipe, or smokeless; n = 262) on average had lower TD (mean = -0.60; SD = 0.84), and the group with the use of multiple tobacco products (n = 471) experienced similar levels of TD (mean = 0.14; SD = 0.78) as the cigarette only use group. Concurrent validity was established with product use frequency among all user groups. A subset of five TD items comprised a common metric permitting comparisons between youth and adults. CONCLUSION: The PATH Study Youth Wave 1 Interview provided psychometrically valid measures of TD that enable future regulatory investigations of TD across tobacco products and comparisons between youth and adult tobacco product use group. IMPLICATIONS: A measure of tobacco dependence (TD) has been established previously among adults to compare TD across tobacco products. This study established the validity of a similar, cross-product measure of TD among youth. Findings suggest a single latent TD construct underlying this measure, concurrent validity of the scale with product use frequency across different types of tobacco users, and a subset of common items that can be used to compare TD between youth and adults who use tobacco.

Update to the design and methods of the PATH Study, Wave 4 (2016-2017).

The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative study of the US population on tobacco use and its effects on health, with four waves of data collection between 2013 and 2017. Prior work described the methods of the first three waves. In this paper, we describe the methods of Wave 4, during which a replenishment sample was added to the ongoing cohort. We describe the design and estimation methods of the continuing Wave 1 cohort (with four waves of data) and the Wave 4 cohort (the new cohort created at Wave 4). We provide survey quality metrics, including response rates for both cohorts and a panel conditioning analysis, and guidance on understanding the target populations for both cohorts.

Association of tobacco product use with chronic obstructive pulmonary disease (COPD) prevalence and incidence in Waves 1 through 5 (2013-2019) of the Population Assessment of Tobacco and Health (PATH) Study.

BACKGROUND: We examined the association of non-cigarette tobacco use on chronic obstructive pulmonary disease (COPD) risk in the Population Assessment of Tobacco and Health (PATH) Study. METHODS: There were 13,752 participants ≥ 40 years with Wave 1 (W1) data for prevalence analyses, including 6945 adults without COPD for incidence analyses; W1-5 (2013-2019) data were analyzed. W1 tobacco use was modeled as 12 mutually-exclusive categories of past 30-day (P30D) single and polyuse, with two reference categories (current exclusive cigarette and never tobacco). Prevalence and incidence ratios of self-reported physician-diagnosed COPD were estimated using weighted multivariable Poisson regression. RESULTS: W1 mean (SE) age was 58.1(0.1) years; mean cigarette pack-years was similar for all categories involving cigarettes and exclusive use of e-cigarettes (all > 20), greater than exclusive cigar users (< 10); and COPD prevalence was 7.7%. Compared to P30D cigarette use, never tobacco, former tobacco, and cigar use were associated with lower COPD prevalence (RR = 0.33, (95% confidence interval-CI) [0.26, 0.42]; RR = 0.57, CI [0.47, 0.70]; RR = 0.46, CI [0.28, 0.76], respectively); compared to never tobacco use, all categories except cigar and smokeless tobacco use were associated with higher COPD prevalence (RR former = 1.72, CI [1.33, 2.23]; RR cigarette = 3.00, CI [2.37, 3.80]; RR e-cigarette = 2.22, CI [1.44, 3.42]; RR cigarette + e-cigarette = 3.10, CI [2.39, 4.02]; RR polycombusted = 3.37, CI [2.44, 4.65]; RR polycombusted plus noncombusted = 2.75, CI]1.99, 3.81]). COPD incidence from W2-5 was 5.8%. Never and former tobacco users had lower COPD risk compared to current cigarette smokers (RR = 0.52, CI [0.35, 0.77]; RR = 0.47, CI [0.32, 0.70], respectively). Compared to never use, cigarette, smokeless, cigarette plus e-cigarette, and polycombusted tobacco use were associated with higher COPD incidence (RR = 1.92, CI [1.29, 2.86]; RR = 2.08, CI [1.07, 4.03]; RR = 1.99, CI [1.29, 3.07]; RR = 2.59, CI [1.60, 4.21], respectively); exclusive use of e-cigarettes was not (RR = 1.36, CI [0.55, 3.39]). CONCLUSIONS: E-cigarettes and all use categories involving cigarettes were associated with higher COPD prevalence compared to never use, reflecting, in part, the high burden of cigarette exposure in these groups. Cigarette-but not exclusive e-cigarette-use was also strongly associated with higher COPD incidence. Compared to cigarette use, only quitting tobacco was protective against COPD development.

Tobacco Use and Respiratory Symptoms Among Adults: Findings From the Longitudinal Population Assessment of Tobacco and Health (PATH) Study 2014-2016.

INTRODUCTION: We examined the relationship between current tobacco use and functionally important respiratory symptoms. METHODS: Longitudinal cohort study of 16 295 US adults without COPD in Waves 2-3 (W2-3, 2014-2016) of the Population Assessment of Tobacco and Health Study. Exposure-Ten mutually exclusive categories of tobacco use including single product, multiple product, former, and never use (reference). Outcome-Seven questions assessing wheezing/cough were summed to create a respiratory symptom index; cutoffs of ≥2 and ≥3 were associated with functional limitations and poorer health. Multivariable regressions examined both cutoffs cross-sectionally and change over approximately 12 months, adjusting for confounders. RESULTS: All tobacco use categories featuring cigarettes (>2/3's of users) were associated with higher risk (vs. never users) for functionally important respiratory symptoms at W2, for example, at symptom severity ≥ 3, risk ratio for exclusive cigarette use was 2.34 [95% CI, 1.92, 2.85] and for worsening symptoms at W3 was 2.80 [2.08, 3.76]. There was largely no increased symptom risk for exclusive use of cigars, smokeless tobacco, hookah, or e-cigarettes (adjustment for pack-years and marijuana attenuated the cross-sectional e-cigarette association from 1.53(95% CI 0.98, 2.40) to 1.05 (0.67, 1.63); RRs for these products were also significantly lower compared to exclusive use of cigarettes. The longitudinal e-cigarette-respiratory symptom association was sensitive to the respiratory index cutoff level; exclusive e-cigarette use was associated with worsening symptoms at an index cutoff ≥ 2 (RR = 1.63 [1.02, 2.59]) and with symptom improvement at an index cutoff of ≥ 3 (RR = 1.64 [1.04, 2.58]). CONCLUSIONS: Past and current cigarette smoking drove functionally important respiratory symptoms, while exclusive use of other tobacco products was largely not associated. However, the relationship between e-cigarette use and symptoms was sensitive to adjustment for pack-years and symptom severity. IMPLICATIONS: How noncigarette tobacco products affect respiratory symptoms is not clear; some studies implicate e-cigarettes. We examined functionally important respiratory symptoms (wheezing/nighttime cough) among US adults without COPD. The majority of adult tobacco users smoke cigarettes and have higher risk of respiratory symptoms and worsening of symptoms, regardless of other products used with them. Exclusive use of other tobacco products (e-cigarettes, cigars, smokeless, hookah) was largely not associated with functionally important respiratory symptoms and risks associated with their use was significantly lower than for cigarettes. The association for e-cigarettes was greatly attenuated by adjustment for cigarette pack-years and sensitive to how symptoms were defined.

Validation of the Wave 1 and Wave 2 Population Assessment of Tobacco and Health (PATH) Study Indicators of Tobacco Dependence Using Biomarkers of Nicotine Exposure Across Tobacco Products.

INTRODUCTION: This study examined the predictive relationships between biomarkers of nicotine exposure and 16-item self-reported level of tobacco dependence (TD) and subsequent tobacco use outcomes. AIMS AND METHODS: The Population Assessment of Tobacco and Health (PATH) Study surveyed adult current established tobacco users who provided urine biospecimens at Wave 1 (September 2013-December 2014) and completed the Wave 2 (October 2014-October 2015) interview (n = 6872). Mutually exclusive user groups at Wave 1 included: Cigarette Only, E-cigarette Only, Cigar Only, Hookah Only, Smokeless Tobacco Only, Cigarette Plus E-cigarette, multiple tobacco product users who smoked cigarettes, and multiple tobacco product users who did not smoke cigarettes. Total Nicotine Equivalents (TNE-2) and TD were measured at Wave 1. Approximate one-year outcomes included frequency/quantity used, quitting, and adding/switching to different tobacco products. RESULTS: For Cigarette Only smokers and multiple tobacco product users who smoked cigarettes, higher TD and TNE-2 were associated with: a tendency to smoke more, smoking more frequently over time, decreased likelihood of switching away from cigarettes, and decreased probability of quitting after one year. For other product user groups, Wave 1 TD and/or TNE-2 were less consistently related to changes in quantity and frequency of product use, or for adding or switching products, but higher TNE-2 was more consistently predictive of decreased probability of quitting. CONCLUSIONS: Self-reported TD and nicotine exposure assess common and independent aspects of dependence in relation to tobacco use behaviors for cigarette smokers. For other product user groups, nicotine exposure is a more consistent predictor of quitting than self-reported TD. IMPLICATIONS: This study suggests that smoking cigarettes leads to the most coherent pattern of associations consistent with a syndrome of TD. Because cigarettes continue to be prevalent and harmful, efforts to decrease their use may be accelerated via conventional means (eg, smoking cessation interventions and treatments), but also perhaps by decreasing their dependence potential. The implications for noncombustible tobacco products are less clear as the stability of tobacco use patterns that include products such as e-cigarettes continue to evolve. TD, nicotine exposure measures, and consumption could be used in studies that attempt to understand and predict product-specific tobacco use behavioral outcomes.

Urinary Nicotine Metabolites and Self-Reported Tobacco Use Among Adults in the Population Assessment of Tobacco and Health (PATH) Study, 2013-2014.

INTRODUCTION: The Population Assessment of Tobacco and Health (PATH) Study is a longitudinal cohort study on tobacco use behavior, attitudes and beliefs, and tobacco-related health outcomes, including biomarkers of tobacco exposure in the U.S. population. In this report we provide a summary of urinary nicotine metabolite measurements among adult users and non-users of tobacco from Wave 1 (2013-2014) of the PATH Study. METHODS: Total nicotine and its metabolites including cotinine, trans-3'-hydroxycotinine (HCTT), and other minor metabolites were measured in more than 11 500 adult participants by liquid chromatography tandem mass spectrometry methods. Weighted geometric means (GM) and least square means from statistical modeling were calculated for non-users and users of various tobacco products. RESULTS: Among daily users, the highest GM concentrations of nicotine, cotinine and HCTT were found in exclusive smokeless tobacco users, and the lowest in exclusive e-cigarette users. Exclusive combustible product users had intermediate concentrations, similar to those found in users of multiple products (polyusers). Concentrations increased with age within the categories of tobacco users, and differences associated with gender, race/ethnicity and educational attainment were also noted among user categories. Recent (past 12 months) former users had GM cotinine concentrations that were more than threefold greater than never users. CONCLUSIONS: These urinary nicotine metabolite data provide quantification of nicotine exposure representative of the entire US adult population during 2013-2014 and may serve as a reference for similar analyses in future measurements within this study. IMPLICATIONS: Nicotine and its metabolites in urine provide perhaps the most fundamental biomarkers of recent nicotine exposure. This report, based on Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study, provides the first nationally representative data describing urinary nicotine biomarker concentrations in both non-users, and users of a variety of tobacco products including combustible, e-cigarette and smokeless products. These data provide a urinary biomarker concentration snapshot in time for the entire US population during 2013-2014, and will provide a basis for comparison with future results from continuing, periodic evaluations in the PATH Study.

Serum Concentrations of Cotinine and Trans-3'-Hydroxycotinine in US Adults: Results From Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health Study.

INTRODUCTION: The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative cohort of tobacco product users and nonusers. The study's main purpose is to obtain longitudinal epidemiologic data on tobacco use and exposure among the US population. AIMS AND METHODS: Nicotine biomarkers-cotinine (COT) and trans-3'-hydroxycotinine (HCT)-were measured in blood samples collected from adult daily tobacco users and nonusers during Wave 1 of the PATH Study (2013-2014; n = 5012; one sample per participant). Participants' tobacco product use and exposure to secondhand smoke were categorized based on questionnaire responses. Nonusers were subdivided into never users and recent former users. Daily tobacco users were classified into seven tobacco product use categories: exclusive users of cigarette, smokeless tobacco, electronic cigarette, cigar, pipe, and hookah, as well as polyusers. We calculated sample-weighted geometric mean (GM) concentrations of cotinine, HCT, and the nicotine metabolite ratio (NMR) and evaluated their associations with tobacco use with adjustment for potential confounders. RESULTS: The GMs (95% confidence intervals) of COT and HCT concentrations for daily tobacco users were 196 (184 to 208) and 72.5 (67.8 to 77.4) ng/mL, and for nonusers they were 0.033 (0.028 to 0.037) and 0.021 (0.018 to 0.023) ng/mL. Exclusive smokeless tobacco users had the highest COT concentrations of all user groups examined. The GM NMR in daily users was 0.339 (95% confidence interval: 0.330 to 0.350). CONCLUSIONS: These nationally representative estimates of serum nicotine biomarkers could be the basis for reference ranges characterizing nicotine exposure for daily tobacco users and nonusers in the US adult population. IMPLICATIONS: This report summarizes the serum nicotine biomarker measurements in Wave 1 of the PATH Study. We are reporting the first estimates of HCT in serum for daily tobacco users and nonusers in the noninstitutionalized, civilian US adult population; the first nationally representative serum COT estimates for daily exclusive users of different tobacco products and daily polyusers; and the first nationally representative estimate of the serum NMR in daily tobacco users by age, race/ethnicity, and sex.

Exposure to Nicotine and Toxicants Among Dual Users of Tobacco Cigarettes and E-Cigarettes: Population Assessment of Tobacco and Health (PATH) Study, 2013-2014.

INTRODUCTION: Concurrent use of tobacco cigarettes and e-cigarettes ("dual use") is common among tobacco users. Little is known about differences in demographics and toxicant exposure among subsets of dual users. AIMS AND METHODS: We analyzed data from adult dual users (current every/some day users of tobacco cigarettes and e-cigarettes, n = 792) included in the PATH Study Wave 1 (2013-2014) and provided urine samples. Samples were analyzed for biomarkers of exposure to nicotine and selected toxicants (tobacco-specific nitrosamine NNK [NNAL], lead, cadmium, naphthalene [2-naphthol], pyrene [1-hydroxypyrene], acrylonitrile [CYMA], acrolein [CEMA], and acrylamide [AAMA]). Subsets of dual users were compared on demographic, behavioral, and biomarker measures to exclusive cigarette smokers (n = 2411) and exclusive e-cigarette users (n = 247). RESULTS: Most dual users were predominant cigarette smokers (70%), followed by daily dual users (13%), non-daily concurrent dual users (10%), and predominant vapers (7%). Dual users who smoked daily showed significantly higher biomarker concentrations compared with those who did not smoke daily. Patterns of e-cigarette use had little effect on toxicant exposure. Dual users with high toxicant exposure were generally older, female, and smoked more cigarettes per day. Dual users who had low levels of biomarkers of exposure were generally younger, male, and smoked non-daily. CONCLUSIONS: In 2013-2014, most dual users smoked cigarettes daily and used e-cigarettes occasionally. Cigarette smoking appears to be the primary driver of toxicant exposure among dual users, with little-to-no effect of e-cigarette use on biomarker levels. Results reinforce the need for dual users to stop smoking tobacco cigarettes to reduce toxicant exposure. IMPLICATIONS: With considerable dual use of tobacco cigarettes and e-cigarettes in the United States, it is important to understand differences in toxicant exposure among subsets of dual users, and how these differences align with user demographics. Findings suggest most dual users smoke daily and use e-cigarettes intermittently. Low exposure to toxicants was most common among younger users, males, and intermittent smokers; high exposure to toxicants was most common among older users, females, and heavier cigarette smokers. Results underscore the heterogeneity occurring within dual users, and the need to quit smoking cigarettes completely in order to reduce toxicant exposure.

Tobacco-Specific Nitrosamines (NNAL, NNN, NAT, and NAB) Exposures in the US Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013-2014).

INTRODUCTION: The tobacco-specific nitrosamines (TSNAs) are an important group of carcinogens found in tobacco and tobacco smoke. To describe and characterize the levels of TSNAs in the Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013-2014), we present four biomarkers of TSNA exposure: N'-nitrosonornicotine, N'-nitrosoanabasine, N'-nitrosoanatabine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) which is the primary urinary metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. METHODS: We measured total TSNAs in 11 522 adults who provided urine using automated solid-phase extraction coupled to isotope dilution liquid chromatography-tandem mass spectrometry. After exclusions in this current analysis, we selected 11 004 NNAL results, 10 753 N'-nitrosonornicotine results, 10 919 N'-nitrosoanatabine results, and 10 996 N'-nitrosoanabasine results for data analysis. Geometric means and correlations were calculated using SAS and SUDAAN. RESULTS: TSNA concentrations were associated with choice of tobacco product and frequency of use. Among established, every day, exclusive tobacco product users, the geometric mean urinary NNAL concentration was highest for smokeless tobacco users (993.3; 95% confidence interval [CI: 839.2, 1147.3] ng/g creatinine), followed by all types of combustible tobacco product users (285.4; 95% CI: [267.9, 303.0] ng/g creatinine), poly tobacco users (278.6; 95% CI: [254.9, 302.2] ng/g creatinine), and e-cigarette product users (6.3; 95% CI: [4.7, 7.9] ng/g creatinine). TSNA concentrations were higher in every day users than in intermittent users for all the tobacco product groups. Among single product users, exposure to TSNAs differed by sex, age, race/ethnicity, and education. Urinary TSNAs and nicotine metabolite biomarkers were also highly correlated. CONCLUSIONS: We have provided PATH Study estimates of TSNA exposure among US adult users of a variety of tobacco products. These data can inform future tobacco product and human exposure evaluations and related regulatory activities.

Longitudinal associations between susceptibility to tobacco use and the onset of other substances among U.S. youth.

We examined whether tobacco susceptibility at Wave (W) 1 (2013-2014) predicts the onset of tobacco and other substances at W2 (2014-2015) among 5325 U.S. youth (12-17 years) never substance users at W1 in the Population Assessment of Tobacco and Health (PATH) Study. Tobacco susceptibility was based on curiosity, use intentions, and response to a best friend's offer to use. Onset of use included past 12-month use of a specific substance or group of substances at W2 among those who had never used any substance at W1. Approximately, 31.3% of W1 youth were susceptible to tobacco use. W2 onset was 8.2% (SE = 0.4) for alcohol exclusively, 5.0% (SE = 0.4) for polysubstance including tobacco, 4.4% (SE = 0.3) for tobacco exclusively, 3.1% (SE = 0.3) for other drugs (misused prescription stimulants and painkillers, cocaine, other stimulants, heroin, inhalants, solvents and hallucinogens) exclusively, 1.4% (SE = 0.2) for polysubstance excluding tobacco, and 0.9% (SE = 0.1) for marijuana exclusively. Tobacco-susceptible compared with non-tobacco susceptible youth had higher odds of onset of exclusive tobacco use (AOR: 2.4; 95% CI: 1.7, 3.3), exclusive alcohol use (AOR: 1.5; 95% CI: 1.2, 1.8), and polysubstance use (AOR: 3.9; 95% CI: 2.8, 5.6 including tobacco and AOR: 1.8; 95% CI: 1.1, 3.0 excluding tobacco) compared with W2 never substance use. In this national study, tobacco susceptibility identified U.S. youth at risk for onset of tobacco and other substances, perhaps reflecting common etiology and clustering of substance use in youth. Identifying and preventing tobacco-susceptible youth from progressing to using addictive substances must remain a public health priority.

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.

Longitudinal transitions of exclusive and polytobacco electronic nicotine delivery systems (ENDS) use among youth, young adults and adults in the USA: findings from the PATH Study Waves 1-3 (2013-2016).

OBJECTIVE: Electronic nicotine delivery systems (ENDS; including e-cigarettes) are rapidly evolving in the US marketplace. This study reports cross-sectional prevalence and longitudinal pathways of ENDS use across 3 years, among US youth (12-17 years), young adults (18-24 years) and adults 25+ (25 years and older). DESIGN: Data were from the first three waves (2013-2016) of the Population Assessment of Tobacco and Health Study, a nationally representative, longitudinal cohort study of US youth and adults. 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: Weighted cross-sectional ever use of ENDS increased at each wave. Across all three waves, young adults had the highest percentages of past 12-month, past 30-day (P30D) and daily P30D ENDS use compared with youth and adults 25+. Only about a quarter of users had persistent P30D ENDS use at each wave. Most ENDS users were polytobacco users. Exclusive Wave 1 ENDS users had a higher proportion of subsequent discontinued any tobacco use compared with polytobacco ENDS users who also used cigarettes. CONCLUSIONS: ENDS use is most common among young adults compared with youth and adults 25+. However, continued use of ENDS over 2 years is not common for any age group. Health education efforts to reduce the appeal and availability of ENDS products might focus on reducing ENDS experimentation, and on reaching the smaller subgroups of daily ENDS users to better understand their reasons for use.