A Machine Learning Approach to Identify Predictors of Frequent Vaping and Vulnerable Californian Youth Subgroups

Introduction Machine learning presents a unique opportunity to improve electronic cigarette (vaping) monitoring in youth. Here we built a random forest model to predict frequent vaping status among Californian youth and to identify contributing factors and vulnerable populations. Methods In this prospective cohort study, 1,281 ever-vaping twelfth-grade students from metropolitan Los Angeles were surveyed in Fall and in 6-month in Spring. Frequent vaping was measured at the 6-month follow-up as nicotine-containing vaping on 20 or more days in past 30 days. Predictors (n=131) encompassed sociodemographic characteristics, substance use and perceptions, health status, and characteristics of the household, school and neighborhood. A random forest was developed to identify the top ten predictors of frequent vaping and interactions by sociodemographic variables. Results Forty participants (3.1%) reported frequent vaping at the follow-up. The random forest outperformed a logistic regression model in prediction (C-Index=0.87 vs. 0.77). Higher past-month nicotine concentration in vape, more daily vaping sessions, and greater nicotine dependence were the top three of the ten most important predictors of frequent vaping. Interactions were found between age and perceived discrimination, and between age and race/ethnicity, as those who were younger than their classmates and either reported experiencing discrimination frequently or identified as Asian or Native American/Pacific Islander were at increased risk of becoming frequent vapers. Conclusions Machine learning can produce models that accurately predict progression of vaping behaviours among youth. The potential association between frequent vaping and perceived discrimination warrants more in-depth analyses to confirm if discrimination constitutes a cause of increased vaping.

Part Two: Pharmacokinetic Evaluation of E-Liquid Flavors of Vuse Solo Electronic Nicotine Delivery System, An Unblinded, Parallel, Randomized Study To Assess Nicotine Uptake In Smokers

This paper reports the findings of a randomized nicotine pharmacokinetic (PK) study of a closed electronic nicotine delivery system (ENDS). The study evaluated four flavor variants of Vuse Solo ENDS where subjects used their randomized investigational product (IP) for 10 minutes ad libitum and blood samples were collected for PK assessments that included maximum plasma nicotine concentration (Cmax) and area under the nicotine concentration-vs-time curve up to 60 minutes (AUCnic0–60). Baseline-adjusted mean Cmax ranged from 6.53 to 8.21 ng/mL, and mean AUCnic0–60 ranged from 206.87 to 263.52 ng*min/mL for all ENDS IPs. Results for Cmax and AUCnic0-60 values were consistent among the ENDS IP flavor variants tested and results indicate that flavors did not affect nicotine uptake in human subjects.

Counseling in Vape Shops: A Survey of Vape Shop Managers in Switzerland

Vaporizers (e-cigarettes) are the most common smoking cessation aids in Switzerland, but we do not know what information customers receive in vape shops. We surveyed vape-shop managers to find out what recommendations they make to their customers. An interdisciplinary group developed the questionnaire. Respondents self-reported their smoking history, demographics, and the recommendations they thought they would give to hypothetical customers in clinical vignettes. We also queried if they collaborated with health care professionals. Of those contacted, 53.8% (70/130) of vape-shop managers responded, and 52.3% (68/130) were included in the final analysis. Managers were mostly male and ex-smokers who switched to vaporizers; 60.3% would encourage a hypothetical smoker with high nicotine dependence to start with the highest possible nicotine concentration when switching to vaporizers. For this smoker, 36.9% would recommend high (≥15 mg/mL), 32.3% medium (6–14 mg/mL), and 3.1% low (1–5 mg/mL) nicotine concentrations. The rest adapted their recommendations to fit the customer or device; 76.5% reported that physicians referred customers to them, and 78.8% would attend a course given by experts in the field of vaporizers and smoking cessation. Vape-shop managers varied widely in the recommendations they gave customers. Most reported ongoing collaboration with health care professionals and were interested in improving their counselling skills through training.

Targeted Characterization of the Chemical Composition of JUUL Systems Aerosol and Comparison with 3R4F Reference Cigarettes and IQOS Heat Sticks

Aerosol constituent yields have been reported from a wide range of electronic nicotine delivery systems. No comprehensive study has been published on the aerosol constituents generated from the JUUL system. Targeted analyses of 53 aerosol constituents from the four JUUL products currently on the US market (Virginia Tobacco and Menthol flavored e-liquids in both 5.0% and 3.0% nicotine concentration by weight) was performed using non-intense and intense puffing regimens. All measurements were conducted by an ISO 17025 accredited contract research organization. JUUL product aerosol constituents were compared to published values for the 3R4F research cigarette and IQOS Regular and Menthol heated tobacco products. Across the four JUUL products and two puffing regimes, only 10/53 analytes were quantifiable, including only two carbonyls (known propylene glycol or glycerol degradants). The remaining analytes were primary ingredients, nicotine degradants and water. Average analyte reductions (excluding primary ingredients and water) for all four JUUL system aerosols tested were greater than 98% lower than 3R4F mainstream smoke, and greater than 88% lower than IQOS aerosol. In summary, chemical characterization and evaluation of JUUL product aerosols demonstrates a significant reduction in toxicants when compared to mainstream cigarette smoke from 3R4F reference cigarettes or aerosols from IQOS-heated tobacco products.

Prevalence of disposable pod use and consumer preference for e-cigarette product characteristics among vape shop customers in Southern California: a cross-sectional study

ObjectivesIn February 2020, the US Food and Drug Administration issued a guidance restricting the sales and distribution of cartridge-based e-cigarettes with flavours other than tobacco and menthol. Disposable devices were exempt from this guidance. This study examined the prevalence of disposable pod use and flavour preference compared with refillable pod and other e-cigarette users among vape shop customers.DesignCross-sectional study.SettingIn July 2019–March 2020, trained data collectors visited 44 vape shops in California with permission to recruit customers from shop owners.ParticipantsIntercept interviews with 276 customers were conducted.Outcomes and proceduresCustomers were grouped based on self-reported device type used most often (disposable pod, refillable pod and other e-cigarettes). Groups were compared on self-reported demographics, flavours preferred, daily e-cigarette use, preferred nicotine concentration levels and cigarette use.ResultsOf the 276 customers surveyed, 11.2% used disposable pods in the past 30 days. Among disposable pod users, fruit/candy (80.7%), mint (77.4%) and menthol (67.7%) were common preferred flavours, while tobacco flavours were less commonly preferred (19.4%). When compared with refillable pod and other non-pod e-cigarette device users, disposable pod users were younger, used higher nicotine concentration levels, were more likely to prefer mint and menthol flavours and use e-cigarettes as their first product, while less likely to ever use cigarettes and use e-cigarettes daily.DiscussionDespite using higher nicotine levels and preferred menthol/mint flavours more often than users of other devices, disposable pod users reported lower prevalence of lifetime smoking and daily vaping and were younger. Given the current findings, regulations addressing non-tobacco flavours and nicotine concentration in disposable pod devices merit consideration in efforts to reduce vaping in younger adult never smokers.

Factors Associated with E-Cigarette Escalation among High School Students: A Review of the Literature

Background: E-cigarette use has been identified as a behaviour of concern among adolescents, and ever and daily use among this population has increased recently. The purpose of this review was to summarize the relevant studies investigating the frequency and intensity of e-cigarette use in adolescents and the factors associated with these patterns of use. Methods: A scoping search of two databases was conducted to identify longitudinal studies examining escalating e-cigarette use among adolescents. Escalating e-cigarette use could refer to an increasing frequency or intensity of use over time. Articles were screened for relevance. Studies that met inclusion criteria were included for synthesis. Results: Five articles were included for synthesis. All five articles were longitudinal studies taking place in the United States between 2013 and 2017. Age, gender, cost of e-cigarettes, use of cigarettes, polysubstance use, and e-liquid nicotine concentration were associated with escalation of e-cigarette use. Conclusions: A paucity of information exists regarding the escalation of e-cigarette use among adolescents. Given the changing popularity of devices, additional updated evidence is needed to understand the factors associated with the escalation of e-cigarette use among adolescents, which can be used to inform local and national programs and policies.

Vaping during the COVID-19 lockdown period in Belgium

Background Due to the Corona Virus Disease 2019 (COVID-19), the Belgian government set out a range of measures to prevent the spread of the virus. One measure included closing all non-food shops, including vape shops. Methods A retrospective online questionnaire was used to investigate the impact of closing the vape shops on the vaping and/or smoking behavior of current vapers. Results The sample (n = 202) reached consisted of 70% exclusive vapers, 29% dual users and 1% no-product users. Over half (55%, 112/202) of participants needed to buy e-liquid during the lockdown, with a small majority being able to buy e-liquids – mostly with their usual nicotine concentrations, flavor or brand –, but as much as 39% (44/112) of them ran out of e-liquid. Those buying e-liquid mainly did so by making purchases via foreign online webshops. A similar pattern was observed with respect to purchasing hardware, with about half (47%, 95/202) of participants reporting hardware availability and with a small majority (53%, 107/202) reporting hardware unavailability. Of those indicating that hardware was not available, 38% (41/107) ran out of a properly functioning e-cigarette. A non-trivial minority had to consume e-liquids with another nicotine concentration, flavor or brand than usual. One seventh of exclusive vapers before lockdown relapsed partly or completely to smoking during the lockdown. The main reasons for changing vaping and/or smoking behavior included the unavailability of e-liquid with nicotine, the unavailability of hardware, and stress/worries about COVID-19. Conclusions The majority of vapers succeeded in maintaining their vaping behavior as usual, highly likely due to (illegally) buying consumables online. Nevertheless, for a minority the lockdown period resulted in unintended consequences and these vapers relapsed (completely) to smoking. Even during periods of lockdown, smokers and vapers should be able to purchase low(er)-risk alternatives to smoking, for example e-cigarettes.