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.

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.

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.

Carbon dioxide utilisation of Dunaliella tertiolecta for carbon bio-mitigation in a semicontinuous photobioreactor.

Bio-fixation of carbon dioxide (CO2) by microalgae has been recognised as an attractive approach to offset anthropogenic emissions. Biological carbon mitigation is the process whereby autotrophic organisms, such as microalgae, convert CO2 into organic carbon and O2 through photosynthesis; this process through respiration produces biomass. In this study Dunaliella tertiolecta was cultivated in a semicontinuous culture to investigate the carbon mitigation rate of the system. The algae were produced in 1.2-L Roux bottles with a working volume of 1 L while semicontinuous production commenced on day 4 of cultivation when the carbon mitigation rate was found to be at a maximum for D. tertiolecta. The reduction in CO2 between input and output gases was monitored to predict carbon fixation rates while biomass production and microalgal carbon content are used to calculate the actual carbon mitigation potential of D. tertiolecta. A renewal rate of 45 % of flask volume was utilised to maintain the culture in exponential growth with an average daily productivity of 0.07 g L(-1) day(-1). The results showed that 0.74 g L(-1) of biomass could be achieved after 7 days of semicontinuous production while a total carbon mitigation of 0.37 g L(-1) was achieved. This represented an increase of 0.18 g L(-1) in carbon mitigation rate compared to batch production of D. tertiolecta over the same cultivation period.

Validating Wave 1 (2014) Urinary Cotinine and TNE-2 Cut-points for Differentiating Wave 4 (2017) Cigarette Use from Non-use in the United States Using Data from the PATH Study.

BACKGROUND: Sex and racial/ethnic identity-specific cut-points for validating tobacco use using Wave 1 (W1) of the Population Assessment of Tobacco and Health (PATH) Study were published in 2020. The current study establishes predictive validity of the W1 (2014) urinary cotinine and total nicotine equivalents-2 (TNE-2) cut-points on estimating Wave 4 (W4; 2017) tobacco use. METHODS: For exclusive and polytobacco cigarette use, weighted prevalence estimates based on W4 self-report alone and with exceeding the W1 cut-point were calculated to identify the percentage missed without biochemical verification. Sensitivity and specificity of W1 cut-points on W4 self-reported tobacco use status were examined. ROC curves were used to determine the optimal W4 cut-points to distinguish past 30-day users from non-users, and evaluate whether the cut-points significantly differed from W1. RESULTS: Agreement between W4 self-reported use and exceeding the W1 cut-points was high overall and when stratified by demographic subgroups (0.7%-4.4% of use was missed if relying on self-report alone). The predictive validity of using the W1 cut-points to classify exclusive cigarette and polytobacco cigarette use at W4 was high (>90% sensitivity and specificity, except among polytobacco Hispanic smokers). Cut-points derived using W4 data did not significantly differ from the W1-derived cut-points [e.g., W1 exclusive = 40.5 ng/mL cotinine (95% confidence interval, CI: 26.1-62.8), W4 exclusive = 29.9 ng/mL cotinine (95% CI: 13.5-66.4)], among most demographic subgroups. CONCLUSIONS: The W1 cut-points remain valid for biochemical verification of self-reported tobacco use in W4. IMPACT: Findings from can be used in clinical and epidemiologic studies to reduce misclassification of cigarette smoking status.

Tobacco Use and Incidence of Adverse Oral Health Outcomes Among US Adults in the Population Assessment of Tobacco and Health Study.

Importance: Evolving tobacco use patterns, including increasing electronic nicotine delivery systems (ENDS) use, warrant re-examination of the associations between tobacco use and oral health. Objective: To examine associations between tobacco product use and incidence of adverse oral health outcomes. Design, Setting, and Participants: This cohort study used nationally representative data from wave (W) 1 to W5 (2013-2019) of the Population Assessment of Tobacco and Health Study. Recruitment used a stratified address-based, area-probability household sample of the noninstitutionalized US civilian population. The W1 cohort included respondents aged 18 years and older without lifetime history of oral health outcomes at W1 or W3, depending on when the outcome was first assessed. Data analysis was performed from October 2021 to September 2022. Exposures: Current (every day or someday use) established (lifetime use of at least 100 cigarettes or "fairly regular" use of other products) use of cigarettes, ENDS, cigars, pipes, hookah, snus, and smokeless tobacco, excluding snus at W1 to W4. Main Outcomes and Measures: The primary outcomes were past 12-month self-reported diagnosis of gum disease and precancerous oral lesions (W2-W5) and bone loss around teeth, bleeding after brushing or flossing, loose teeth, and 1 or more teeth removed (W4-W5). Results: Sample sizes varied across the 6 oral health outcomes (13 149 respondents for the gum disease sample, 14 993 respondents for the precancerous oral lesions sample, 16 312 respondents for the bone loss around teeth sample, 10 286 respondents for the bleeding after brushing or flossing sample, 15 686 respondents for the loose teeth sample, and 12 061 respondents for the 1 or more teeth removed sample). Slightly more than half of adults (52%-54% across the 6 samples) were women, and the majority were of non-Hispanic White race and ethnicity. Cox proportional hazards models were developed with covariates that included time-dependent tobacco use variables mutually adjusted for each other. Cigarette smoking was positively associated with incidence of gum disease diagnosis (adjusted hazard ratio [AHR], 1.33; 95% CI, 1.11-1.60), loose teeth (AHR, 1.35; 95% CI, 1.05-1.75), and 1 or more teeth removed (AHR, 1.43; 95% CI, 1.18-1.74). Cigar smoking was positively associated with incidence of precancerous oral lesions (AHR, 2.18; 95% CI, 1.38-3.43). In addition, hookah smoking was positively associated with incidence of gum disease diagnosis (AHR, 1.78; 95% CI, 1.20-2.63), and ENDS use was positively associated with incidence of bleeding after brushing or flossing (AHR, 1.27; 95% CI, 1.04-1.54). No associations were observed between snus and smokeless tobacco excluding snus and incidence of oral health outcomes. Conclusions and Relevance: The observed associations of combustible tobacco use with incidence of several adverse oral health outcomes and ENDS use with incidence of bleeding after brushing or flossing highlight the importance of longitudinal studies and emphasize the continued importance of tobacco cessation counseling and resources in clinical practice.

E-cigarette use and change in plans to quit cigarette smoking among adult smokers in the United States: Longitudinal findings from the PATH Study 2014-2019.

INTRODUCTION: Much of the population-based e-cigarette use and cigarette cessation literature is restricted to smokers who have expressed intention to quit smoking, though experimental studies suggest e-cigarette use might motivate some smokers to change their quit intentions. We used U.S. nationally representative data to evaluate whether e-cigarette use by smokers initially not planning to ever quit is associated with change in plans to quit. METHODS: Longitudinal Population Assessment of Tobacco and Health (PATH) Study data collected between 2014 and 2019 were analyzed. Main analyses were conducted among adult daily cigarette smokers not currently using e-cigarettes with no plans to ever quit smoking (n = 2366 observations from n = 1532 individuals). Generalized estimating equations were used to evaluate the association between change in e-cigarette use and change in plans to quit smoking within the next six months, over three assessment pairs. RESULTS: Daily cigarette smokers with no plans to quit had a higher rate of change to plan to quit if at follow-up they used e-cigarettes daily (41.4%, 95% CI: 27.1-57.3%) versus not at all (12.4%, 95% CI: 10.6-14.5%; aOR = 5.7, 95% CI: 2.9-11.2). Rate of change to plan to quit did not statistically differ between those who at follow-up used e-cigarettes some days versus not at all. CONCLUSIONS: Among adult daily cigarette smokers initially not planning to ever quit, subsequent daily e-cigarette use is associated with subsequent plans to quit smoking. Population-level research on e-cigarette use that is focused on smokers already motivated to quit may limit a complete evaluation of the smoker population.

Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population Assessment of Tobacco and Health Study, 2013-2015.

Limited data are available for how biomarkers of tobacco exposure (BOE) change when cigarette smokers transition to using electronic nicotine delivery systems (ENDS). Using biomarker data from Waves 1 (2013-2014) and 2 (2014-2015) of the PATH Study, we examined how mean BOE concentrations, including metabolites of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC) and metals, changed when 2475 adult smokers transitioned to using ENDS or quit tobacco products. Exclusive smokers who transitioned to dual use had a significant decrease in NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), but not nicotine metabolites, most PAHs, metals, or VOCs. Exclusive smokers who became dual users had significant reductions in total nicotine equivalents, NNAL, and 2CyEMA (acrylonitrile metabolite), but only in those who reduced cigarettes per day (CPD) by >=50%. Smokers who transitioned to exclusive ENDS use had significant reductions in most TSNAs, PAHs, and VOCs; however, nicotine metabolites did not decrease in dual users who became exclusive ENDS users. Smokers who quit tobacco use had significant decreases in nicotine metabolites, all TSNAs, most PAHs, and most VOCs. Cigarette smokers who became dual users did not experience significant reductions in most BOEs. Reductions were impacted by changes in CPD. However, transitioning from smoking to no tobacco or exclusive ENDS use was associated with reduced exposure to most BOEs measured. Future analyses could incorporate additional waves of PATH data and examine changes in biomarker exposure by ENDS device type and CPD.

Urinary Cotinine and Cotinine + Trans-3'-Hydroxycotinine (TNE-2) Cut-points for Distinguishing Tobacco Use from Nonuse in the United States: PATH Study (2013-2014).

BACKGROUND: Determine the overall, sex-, and racially/ethnically-appropriate population-level cotinine and total nicotine equivalents (TNE-2, the molar sum of the two major nicotine metabolites) cut-points to distinguish tobacco users from nonusers across multiple definitions of use (e.g., exclusive vs. polytobacco, and daily vs. non-daily). METHODS: Using Wave 1 (2013-2014) of the U.S. Population Assessment of Tobacco and Health (PATH) Study, we conducted weighted Receiver Operating Characteristic (ROC) analysis to determine the optimal urinary cotinine and TNE-2 cut-points, stratified by sex and race/ethnicity. RESULTS: For past 30-day exclusive cigarette users, the cotinine cut-point that distinguished them from nonusers was 40.5 ng/mL, with considerable variation by sex (male: 22.2 ng/mL; female: 43.1 ng/mL) and between racial/ethnic groups (non-Hispanic other: 5.2 ng/mL; non-Hispanic black: 297.0 ng/mL). A similar, but attenuated, pattern emerged when assessing polytobacco cigarette users (overall cut-point = 39.1 ng/mL, range = 5.5 ng/mL-80.4 ng/mL) and any tobacco users (overall cut-point = 39.1 ng/mL, range = 4.8 ng/mL-40.0 ng/mL). Using TNE-2, which is less impacted by racial differences in nicotine metabolism, produced a comparable pattern of results although reduced the range magnitude. CONCLUSIONS: Because of similar frequency of cigarette use among polytobacco users, overall cut-points for exclusive cigarette use were not substantially different from cut-points that included polytobacco cigarette use or any tobacco use. Results revealed important differences in sex and race/ethnicity appropriate cut-points when evaluating tobacco use status and established novel urinary TNE-2 cut-points. IMPACT: These cut-points may be used for biochemical verification of self-reported tobacco use in epidemiologic studies and clinical trials.

Association of Electronic Nicotine Delivery System Use With Cigarette Smoking Relapse Among Former Smokers in the United States.

Importance: Relapse to smoking among former smokers is a serious clinical concern, and use of electronic nicotine delivery systems (ENDS) has been proposed as a new risk factor for relapse. Understanding the specificity of this risk can help guide clinical practice and lead to improved health outcomes. Objective: To assess the associations of ENDS use with cigarette smoking relapse among adult former cigarette smokers. Design, Setting, and Participants: This cohort study examined data from the Population Assessment of Tobacco and Health Study, waves 1 to 4 (2013-2018). Cox proportional hazards models were developed. This is an ongoing, nationally representative, longitudinal cohort study in the US. Participants included adult (≥18 years) former cigarette smokers who reported no tobacco product use at wave 1 (unweighted n = 2273), separated into recent former cigarette smokers (last smoked ≤12 months previously) and long-term former smokers (last smoked >12 months previously). Data analysis was conducted from July to August 2019. Exposures: Self-reported use of cigarettes, ENDS, and other tobacco products (ie, cigars, pipe tobacco, hookah, snus tobacco, other smokeless tobacco, and dissolvable tobacco) was assessed. Main Outcomes and Measures: Self-reported current (every day or some days) use of cigarettes at follow-up interviews. Results: Of 2273 adult former cigarette smokers, 51.8% (95% CI, 49.7%-53.8%) were women, 65.0% (95% CI, 62.6%-67.4%) were older than 50 years, and 79.5% (95% CI, 77.8%-81.2%) were non-Hispanic white participants. Use of ENDS was associated with significant risk of cigarette smoking relapse among recent former smokers (adjusted hazard ratio [AHR], 1.63; 95% CI, 1.04-2.53; unweighted n = 304) and among long-term former smokers (AHR, 3.79; 95% CI, 1.75-8.20; unweighted n = 1554). Use of other tobacco products was also associated with significant risk for cigarette smoking relapse among recent former smokers (AHR, 1.97; 95% CI, 1.27-3.05) and among long-term former smokers (AHR, 3.82; 95% CI, 1.91-7.66). Conclusions and Relevance: In this study, use of ENDS and other tobacco products was associated with increased risk of cigarette smoking relapse among former cigarette smokers who did not use any tobacco product at wave 1 of the PATH Study. For clinicians treating former smokers who have successfully quit all nicotine products, the implications are that use of ENDS products should be discouraged, just as use of all other tobacco products is discouraged.

Prediction of moisture, calorific value, ash and carbon content of two dedicated bioenergy crops using near-infrared spectroscopy.

The potential of near infrared spectroscopy in conjunction with partial least squares regression to predict Miscanthus xgiganteus and short rotation coppice willow quality indices was examined. Moisture, calorific value, ash and carbon content were predicted with a root mean square error of cross validation of 0.90% (R(2) = 0.99), 0.13 MJ/kg (R(2) = 0.99), 0.42% (R(2) = 0.58), and 0.57% (R(2) = 0.88), respectively. The moisture and calorific value prediction models had excellent accuracy while the carbon and ash models were fair and poor, respectively. The results indicate that near infrared spectroscopy has the potential to predict quality indices of dedicated energy crops, however the models must be further validated on a wider range of samples prior to implementation. The utilization of such models would assist in the optimal use of the feedstock based on its biomass properties.

Modelling of sensory and instrumental texture parameters in processed cheese by near infrared reflectance spectroscopy.

This study investigated the application of near infrared (NIR) reflectance spectroscopy to the measurement of texture (sensory and instrumental) in experimental processed cheese samples. Spectra (750 to 2498 nm) of cheeses were recorded after 2 and 4 weeks storage at 4 degrees C. Trained assessors evaluated 9 sensory properties, a texture profile analyser (TPA) was used to record 5 instrumental parameters and cheese 'meltability' was measured by computer vision. Predictive models for sensory and instrumental texture parameters were developed using partial least squares regression on raw or pre-treated spectral data. Sensory attributes and instrumental texture measurements were modelled with sufficient accuracy to recommend the use of NIR reflectance spectroscopy for routine quality assessment of processed cheese.