Using Large Language Models to Support Content Analysis: A Case Study of ChatGPT for Adverse Event Detection.

This study explores the potential of using large language models to assist content analysis by conducting a case study to identify adverse events (AEs) in social media posts. The case study compares ChatGPT's performance with human annotators' in detecting AEs associated with delta-8-tetrahydrocannabinol, a cannabis-derived product. Using the identical instructions given to human annotators, ChatGPT closely approximated human results, with a high degree of agreement noted: 94.4% (9436/10,000) for any AE detection (Fleiss κ=0.95) and 99.3% (9931/10,000) for serious AEs (κ=0.96). These findings suggest that ChatGPT has the potential to replicate human annotation accurately and efficiently. The study recognizes possible limitations, including concerns about the generalizability due to ChatGPT's training data, and prompts further research with different models, data sources, and content analysis tasks. The study highlights the promise of large language models for enhancing the efficiency of biomedical research.

Declines in cigarette smoking among US adolescents and young adults: indications of independence from e-cigarette vaping surge.

OBJECTIVE: To compare trends in cigarette smoking and nicotine vaping among US population aged 17-18 years and 18-24 years. METHODS: Regression analyses identified trends in ever and current use of cigarettes and e-cigarettes, using three US representative surveys from 1992 to 2022. RESULTS: From 1997 to 2020, cigarette smoking prevalence among those aged 18-24 years decreased from 29.1% (95% CI 27.4% to 30.7%) to 5.4% (95% CI 3.9% to 6.9%). The decline was highly correlated with a decline in past 30-day smoking among those aged 17-18 years (1997: 36.8% (95% CI 35.6% to 37.9%; 2022: 3.0% (95% CI 1.8% to 4.1%). From 2017 to 2019, both ever-vaping and past 30-day nicotine vaping (11.0% to 25.5%) surged among those 17-18 years, however there was no increase among those aged 18-24 years. Regression models demonstrated that the surge in vaping was independent of the decline in cigarette smoking. In the 24 most populous US states, exclusive vaping did increase among those aged 18-24 years, from 1.7% to 4.0% to equivalent to 40% of the decline in cigarette smoking between 2014-15 and 2018-19. Across these US states, the correlation between the changes in vaping and smoking prevalence was low (r=0.11). In the two US states with >US$1/fluid mL tax on e-cigarettes in 2017, cigarette smoking declined faster than the US average. CONCLUSIONS: Since 1997, a large decline in cigarette smoking occurred in the US population under age 24 years, that was independent of the 2017-19 adolescent surge in past 30-day e-cigarette vaping. Further research is needed to assess whether the 2014-15 to 2018-19 increase in exclusive vaping in those aged 18-24 years is a cohort effect from earlier dependence on e-cigarette vaping as adolescents.

E-commerce licensing loopholes: a case study of online shopping for tobacco products following a statewide sales restriction on flavoured tobacco in California.

INTRODUCTION: Retailer licensing programmes can be an effective method of enforcing tobacco control laws, but most programmes do not require e-commerce retailers to obtain licenses. California's implementation of a statewide flavour restriction (Senate Bill 793 (SB-793)) in December 2022 enforced through its tobacco retailer licensing programme presented an opportunity to assess whether the exclusion of e-commerce in the definition of 'tobacco retailer' might have resulted in a shift in consumer behaviour towards e-commerce. METHODS: To examine the association between SB-793 implementation and online shopping for tobacco, we collected weekly Google search rates related to online shopping for cigarettes and vaping products in California from January 2018 to May 2023. We compared observed rates of shopping queries after SB-793 implementation to counterfactual expected rates and prediction intervals (PI) calculated from autoregressive iterative moving average models fit to historical trends. Content analysis was performed on the search results to identify websites marketing flavoured vaping products and menthol cigarettes. RESULTS: The week SB-793 was implemented, shopping queries were 194.4% (95% PI 100.8% to 451.5%) and 161.7% (95% PI 81.7% to 367.5%) higher than expected for cigarettes and vapes, respectively. Cigarette shopping queries remained elevated significantly for 11 weeks and vape shopping queries for 6 weeks. All search results contained links to websites that offered flavoured vaping products or menthol cigarettes to Californian consumers. DISCUSSION: These findings raise concerns about potential loopholes in policy enforcement created by the absence of explicit regulations on e-commerce sales in retailer licensing programmes. Strengthening regulations to include e-commerce and monitoring e-commerce compliance are recommended to enhance the impact of laws enforced through retailer licensing programmes.

Kratom availability in California vape shops.

Kratom products are derived from trees native to Southeast Asia and have dose-dependent stimulant and opioid-like effects. Despite being on the Drug Enforcement Administration "Drugs and Chemicals of Concern List," kratom is legal for sale in most US states. However, there are scarce data on its availability. The goal of this study was to examine kratom availability in vape shops across the state of California and assess shop compliance with a local kratom sales ban (enacted in 2016) in San Diego City. As part of a larger study about retail tobacco marketing near colleges, availability of kratom was assessed in summer 2019 in a random sample of 614 vape shops that was stratified to compare stores near (≤ 3 miles) and distant (>3 miles) from colleges. Logistic regression examined kratom availability as a function of store type (stores that sold vape products only vs. stores selling other tobacco), nearness to college, and tract-level demographics. Kratom was available in 62.4% of observed stores and more often in vape-and-smoke (81.1%) than vape-only shops (11.5%, AOR = 40.4, 95% CI = 23.3-74.1). Kratom availability did not differ by nearness to colleges. In San Diego City, 46.2% of observed stores (95% CI = 28.8-64.5) sold kratom products. Findings indicate that kratom was available in the majority of vape shops and most commonly in vape-and-smoke shops. Widespread availability in tobacco specialty shops suggests the need for research on dual use with tobacco, kratom advertising and cross-product promotion, and the potential of state and local tobacco retail licensing to prohibit sales.

Evaluating Artificial Intelligence Responses to Public Health Questions.

This cross-sectional study analyzes the quality of ChatGPT responses to public health questions.

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.

Self-reported adverse events associated with ∆8-Tetrahydrocannabinol (Delta-8-THC) Use.

BACKGROUND: There is an expanding unregulated market for a psychotropic compound called ∆8-Tetrahydrocannabinol (delta-8-THC) that is being derived from hemp, but a summary of adverse events related to delta-8-THC has not been publicly reported. METHODS: This case series assessed adverse events reported by delta-8-THC users on the Reddit forum r/Delta8 and compared these to delta-8-THC AEs in the US Food and Drug Administration Adverse Event Reporting System (FAERS). Delta-8-THC and cannabis AEs reported in FAERS were also compared. The r/Delta8 forum was selected because it includes a large sample of 98,700 registered individuals who publicly discuss their experiences using delta-8-THC. All r/Delta8 posts were obtained from August 20, 2020, through September 25, 2022. A random sample of r/Delta8 posts was drawn (n = 10,000) and filtered for posts in which delta-8-THC users reported an adverse event (n = 335). FAERS reports that listed delta-8-THC (N = 326) or cannabis (N = 7076) as a suspect product active ingredient were obtained. Adverse events claimed to result from delta-8-THC use were coded using Medical Dictionary for Regulatory Activities to system organ class and preferred term categories. RESULTS: The absolute number of delta-8-THC adverse event reports (N = 2184, 95% CI = 1949-2426) and serious adverse event reports (N = 437; 95% CI = 339-541) on r/Delta 8 were higher than the adverse event reports (N = 326) and serious adverse event reports (N = 289) to FAERS. Psychiatric disorders were the most frequently cited system organ class in r/Delta8 adverse event reports, mentioned in 41.2% (95% CI = 35.8%-46.3%) of reports, followed by respiratory, thoracic and mediastinal disorders (29.3%, 95% CI = 25.1%-34.0%) and nervous system disorders (23.3%, 95% CI = 18.5%-27.5%). Anxiety (16.4%, 95% CI = 12.8-20.6), Cough (15.5%, 95% CI = 11.9-20.0) and Paranoia (9.3%, 95% CI = 6.3-12.5) were the most frequently cited preferred terms in adverse event reports. The overall prevalence of AEs reported for cannabis and delta-8-THC on FAERS were also similar when analyzed by system organ class (Pearson's r = 0.88). CONCLUSIONS: The findings of this case series suggest that most of the adverse events reported by delta-8-THC users are like those reported during acute cannabis intoxication. This finding suggests that health care professionals follow similar treatment and management protocols, and that jurisdictions should clarify whether delta-8-THC can be sold as a hemp product.

Comparing Physician and Artificial Intelligence Chatbot Responses to Patient Questions Posted to a Public Social Media Forum.

Importance: The rapid expansion of virtual health care has caused a surge in patient messages concomitant with more work and burnout among health care professionals. Artificial intelligence (AI) assistants could potentially aid in creating answers to patient questions by drafting responses that could be reviewed by clinicians. Objective: To evaluate the ability of an AI chatbot assistant (ChatGPT), released in November 2022, to provide quality and empathetic responses to patient questions. Design, Setting, and Participants: In this cross-sectional study, a public and nonidentifiable database of questions from a public social media forum (Reddit's r/AskDocs) was used to randomly draw 195 exchanges from October 2022 where a verified physician responded to a public question. Chatbot responses were generated by entering the original question into a fresh session (without prior questions having been asked in the session) on December 22 and 23, 2022. The original question along with anonymized and randomly ordered physician and chatbot responses were evaluated in triplicate by a team of licensed health care professionals. Evaluators chose "which response was better" and judged both "the quality of information provided" (very poor, poor, acceptable, good, or very good) and "the empathy or bedside manner provided" (not empathetic, slightly empathetic, moderately empathetic, empathetic, and very empathetic). Mean outcomes were ordered on a 1 to 5 scale and compared between chatbot and physicians. Results: Of the 195 questions and responses, evaluators preferred chatbot responses to physician responses in 78.6% (95% CI, 75.0%-81.8%) of the 585 evaluations. Mean (IQR) physician responses were significantly shorter than chatbot responses (52 [17-62] words vs 211 [168-245] words; t = 25.4; P < .001). Chatbot responses were rated of significantly higher quality than physician responses (t = 13.3; P < .001). The proportion of responses rated as good or very good quality (≥ 4), for instance, was higher for chatbot than physicians (chatbot: 78.5%, 95% CI, 72.3%-84.1%; physicians: 22.1%, 95% CI, 16.4%-28.2%;). This amounted to 3.6 times higher prevalence of good or very good quality responses for the chatbot. Chatbot responses were also rated significantly more empathetic than physician responses (t = 18.9; P < .001). The proportion of responses rated empathetic or very empathetic (≥4) was higher for chatbot than for physicians (physicians: 4.6%, 95% CI, 2.1%-7.7%; chatbot: 45.1%, 95% CI, 38.5%-51.8%; physicians: 4.6%, 95% CI, 2.1%-7.7%). This amounted to 9.8 times higher prevalence of empathetic or very empathetic responses for the chatbot. Conclusions: In this cross-sectional study, a chatbot generated quality and empathetic responses to patient questions posed in an online forum. Further exploration of this technology is warranted in clinical settings, such as using chatbot to draft responses that physicians could then edit. Randomized trials could assess further if using AI assistants might improve responses, lower clinician burnout, and improve patient outcomes.

Trends in cigarette consumption across the United States, with projections to 2035.

OBJECTIVES: To make projections of cigarette consumption that incorporate state-specific trends in smoking behaviors, assess the potential for states to reach an ideal target, and identify State-specific targets for cigarette consumption. METHODS: We used 70 years (1950-2020) of annual state-specific estimates of per capita cigarette consumption (expressed as packs per capita or "ppc") from the Tax Burden on Tobacco reports (N = 3550). We summarized trends within each state by linear regression models and the variation in rates across states by the Gini coefficient. Autoregressive Integrated Moving Average (ARIMA) models were used to make state-specific forecasts of ppc from 2021 through 2035. RESULTS: Since 1980, the average rate of decline in US per capita cigarette consumption was 3.3% per year, but rates of decline varied considerably across US states (SD = 1.1% per year). The Gini coefficient showed growing inequity in cigarette consumption across US states. After reaching its lowest level in 1984 (Gini = 0.09), the Gini coefficient began increasing by 2.8% (95% CI: 2.5%, 3.1%) per year from 1985 to 2020 and is projected to continue to increase by 48.1% (95% PI = 35.3%, 64.2%) from 2020 to 2035 (Gini = 0.35; 95% PI: 0.32, 0.39). Forecasts from ARIMA models suggested that only 12 states have a realistic chance (≥50%) of reaching very low levels of per capita cigarette consumption (≤13 ppc) by 2035, but that all US states have opportunity to make some progress. CONCLUSION: While ideal targets may be out of reach for most US states within the next decade, every US state has the potential to lower its per capita cigarette consumption, and our identification of more realistic targets may provide a helpful incentive.

Effects of menthol use and transitions in use on short-term and long-term cessation from cigarettes among US smokers.

OBJECTIVES: To estimate the effect of menthol use and transitions in use (switching to or from menthol) on short-term and long-term cessation from cigarette smoking and whether this differed across demographic groups (age, sex, race). METHODS: We compared the probability of 30+ day and 12-month abstinence from cigarette smoking by menthol use status using two cohorts of US adult cigarette smokers who attempted to quit smoking in the Population Assessment of Tobacco and Health (wave 1 to wave 3 and wave 2 to wave 4; n=5759), inverse probability of treatment weighting and adjusted risk ratios (aRRs). RESULTS: Using menthol (vs non-menthol) prior to a quit attempt decreased the probability of 30+ day abstinence by 28% (aRR=0.78; 95% CI 0.67 to 0.91) and the probability of 12-month abstinence by 53% (aRR=0.65; 95% CI 0.47 to 0.88). Additionally, switching from menthol (vs maintaining menthol use) increased the probability of 30+ day abstinence by 58% (aRR=1.58; 95% CI 1.00 to 2.50) and the probability of 12-month abstinence by 97% (aRR=1.86; 95% CI 0.92 to 3.74). Switching to menthol (vs maintaining non-menthol use) was associated with a lower probability of 30+ day (aRR=0.70; 95% CI 0.42 to 1.16) and 12-month abstinence (aRR=0.64; 95% CI 0.30 to 1.36), but these associations were imprecise. The effects of menthol use on impaired quitting were slightly larger for non-Hispanic Black smokers, but not different for other demographic groups. CONCLUSION: These results demonstrate that menthol impaired menthol smokers' attempts to quit smoking but switching from menthol improved success. This suggests that removing menthol may improve menthol smokers' success during quit attempts.

Evaluating US smokers' willingness to pay for different cigarette packaging designs before and after real-world exposure in a randomised trial.

INTRODUCTION: Removal of tobacco industry branding from cigarette packs may reduce their appeal. Adding graphic warning labels (GWLs) should enhance this effect. We investigate whether willingness to pay for various packaging designs changes after 3 months' use of: (1) US branded packs without GWLs (US), (2) non-branded packs without GWLs (Blank), and (3) rotating non-branded packs with GWLs (gangrene; throat cancer; neonatal baby) covering >75% of pack (GWL). METHODS: Californian adult daily smokers not planning to quit (n=287; 56% female; mean age=39.6) completed a discrete choice purchase task before and after 3 months' experience using one of three packaging options. Conjoint analysis and pre-post modelling evaluated the change in importance of pack attributes and willingness to pay for US, Blank or GWL (blindness; teeth; gangrene) pack designs. RESULTS: Price determined ~70% of purchase choices, while pack design determined ~22%. Irrespective of intervention arm, US packaging generated appeal valuations compared with Blank packaging, while GWLs consistently provoked strong aversive valuations at baseline and follow-up. Compared with the US pack arm, using GWL packs for 3 months decreased willingness to pay for US packaging (ß=-$0.38, 95% CI -0.76 to 0.00). Wear-out effects were detected in the discount needed to willingly purchase the gangrene-GWL pack (ß=$0.49, 95% CI 0.16 to 0.82) and Blank pack (ß=$0.42, 95% CI 0.09 to 0.74) but not for GWLs (blindness, teeth) not used in trial. CONCLUSION: Compared with US branded packs, the negative valuation of non-branded GWL packs attenuates with even 3 months' use but does not generalise to non-used GWLs. This suggests that GWLs should be regularly refreshed. The appeal valuation of industry imagery suggests that the US plan to retain such imagery on packs may ameliorate the effect of GWLs.

Role of affective reactivity induced by cigarette packaging including graphic warning labels: the CASA Study.

OBJECTIVE: To identify whether three types of cigarette pack designs, including three versions of graphic warning label (GWL) plain packs, one GWL absent and branding absent pack (blank) and the smoker's own GWL absent and branding present pack (US), elicit different valence, type and levels of affect. DESIGN: US daily smokers (n=324) were asked to handle each of the five pack types and 'think aloud' their reactions. To avoid a muted familiarity response, exposure to their own US pack followed exposure to at least one GWL plain pack. Reactions were scored on a reactivity scale (-3 to +3) and the text was coded for speech polarity (-1 to +1) and emotive word frequency. RESULTS: Reactivity scores had excellent inter-rater reliability (agreement ≥86%; intraclass correlation coefficient ≥0.89) and were correlated with speech polarity (r=0.21-0.37, p<0.001). When considering their US pack, approximately two-thirds of smokers had a low (31.5%) to medium (34.6%) positive response (reactivity=1.29; polarity=0.14) with expressed feelings of joy and trust. Blank packaging prompted a largely (65.4%) neutral response (reactivity=0.03; polarity=0.00). The gangrenous foot GWL provoked mostly medium (46.9%) to high (48.1%) negative responses (reactivity=-2.44; polarity=-0.20), followed by neonatal baby (reactivity=-1.85; polarity=-0.10) and throat cancer (reactivity=-1.76; polarity=-0.08) warnings. GWLs varied in their elicitation of disgust, anger, fear and sadness. CONCLUSION: Initial reactions to GWL packs, a blank pack, and smokers' current US pack reflected negative, neutral, and positive affect, respectively. Different versions of the GWL pack elicited different levels and types of immediate negative affect.

Effectiveness of e-cigarettes as aids for smoking cessation: evidence from the PATH Study cohort, 2017-2019.

OBJECTIVE: To assess the effectiveness of e-cigarettes in smoking cessation in the USA from 2017 to 2019, given the 2017 increase in high nicotine e-cigarette sales. METHODS: In 2017, the PATH Cohort Study included data on 3578 previous year smokers with a recent quit attempt and 1323 recent former smokers. Respondents reported e-cigarettes or other products used to quit cigarettes and many covariates associated with e-cigarette use. Study outcomes were 12+ months of cigarette abstinence and tobacco abstinence in 2019. We report weighted unadjusted estimates and use propensity score matched analyses with 1500 bootstrap samples to estimate adjusted risk differences (aRD). RESULTS: In 2017, 12.6% (95% CI 11.3% to 13.9%) of recent quit attempters used e-cigarettes to help with their quit attempt, a decline from previous years. Cigarette abstinence for e-cigarette users (9.9%, 95% CI 6.6% to 13.2%) was lower than for no product use (18.6%, 95% CI 16.0% to 21.2%), and the aRD for e-cigarettes versus pharmaceutical aids was -7.3% (95% CI -14.4 to -0.4) and for e-cigarettes versus any other method was -7.7% (95% CI -12.2 to -3.2). Only 2.2% (95% CI 0.0% to 4.4%) of recent former smokers switched to a high nicotine e-cigarette. Subjects who switched to e-cigarettes appeared to have a higher relapse rate than those who did not switch to e-cigarettes or other tobacco, although the difference was not statistically significant. CONCLUSIONS: Sales increases in high nicotine e-cigarettes in 2017 did not translate to more smokers using these e-cigarettes to quit smoking. On average, using e-cigarettes for cessation in 2017 did not improve successful quitting or prevent relapse.

Effect of Graphic Warning Labels on Cigarette Pack-Hiding Behavior Among Smokers: The CASA Randomized Clinical Trial.

Importance: The inclusion of graphic warning labels (GWLs) on cigarette packs is recommended for tobacco control but has not yet been implemented in the US. It is unknown whether and to what extent the inclusion of GWLs on cigarette packs affects smokers' willingness to display the packs in public. Objective: To determine whether the inclusion of GWLs on cigarette packs affects pack-hiding behavior among smokers in social settings. Design, Setting, and Participants: This community-based randomized clinical trial assessed smokers' real-world experience of using cigarettes repackaged to include GWLs (GWL packs) compared with standard US packs and blank packs over a 3-month intervention period with 12 months of follow-up between September 6, 2016, and December 3, 2019. The study included 357 participants aged 21 to 65 years from San Diego County, California, who smoked 5 or more cigarettes per day, were not actively planning to quit smoking, were not pregnant, and had no unstable medical conditions. Participants purchased and received cigarette packs through the study website. Interventions: During the 1-month run-in period, participants received their usual US cigarette packs. During the 3-month intervention period, participants were randomized to receive GWL packs (study-manufactured packs with 3 rotating images under license from the Commonwealth of Australia; GWL pack group), blank packs (study-manufactured packs devoid of industry marketing imagery; blank pack group), or standard US packs (US pack group). Main Outcomes and Measures: Pack hiding was queried daily (with participants reporting behavior within the last 4 hours) and weekly via interactive text messages during the 1-month run-in and intervention periods. Self-reported smoking behavior was biochemically validated. Results: Among 357 enrolled participants, the mean (SD) age was 39.3 (11.8) years; 195 participants (54.6%) were female, 40 (11.2%) were Hispanic, 243 (68.1%) were non-Hispanic White, and 74 (20.7%) were of other non-Hispanic races (including American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, or multiracial). A total of 18 987 cigarette packs were purchased and delivered during the run-in and intervention periods. Daily querying showed that the inclusion of GWLs on cigarette packs increased the percentage of smokers who hid their packs at least some of the time from 41.3% (95% CI, 39.6%-43.0%) during the run-in period to 57.1% (95% CI, 55.9%-58.1%) by the end of the intervention period. In the postintervention period, returning to standard US packs reduced pack-hiding behavior to the levels observed during the run-in period. Pack hiding remained at run-in levels for both the blank pack group (35.2%; 95% CI, 33.6%-36.8%) and the US pack group (41.4%; 95% CI, 39.7%-43.1%]) throughout the study. Although even participants in the GWL group with the lowest prestudy tendency to conceal score (ie, 1) had a mean (SE) probability of pack hiding during the intervention of 0.84 (0.02), this group's probability of pack hiding decreased to a mean (SE) of 0.43 (0.03) after intervention. When social reactions to packs were queried at the end of the study, the modal response from participants in the GWL pack group was observers' aversive reactions to the packs, whereas the modal response from participants in the blank pack group was observers' positive interest in the study. Neither smoking prevalence nor consumption differed by group at any point in the study. Conclusions and Relevance: In this randomized clinical trial, receiving cigarettes in GWL packs vs blank packs increased pack-hiding behavior in social settings, which may be associated with aversive reactions from observers. However, 12-month smoking behavior did not change. Trial Registration: ClinicalTrials.gov Identifier: NCT02676193.

Use of Menthol Cigarettes, Smoking Frequency, and Nicotine Dependence Among US Youth.

Importance: Menthol may make cigarette smoke less aversive and could lead youth to smoke more frequently and become more dependent on nicotine. Objective: To assess the association of menthol use with cigarette smoking frequency and nicotine dependence (ND) among youth cigarettes users. Design, Setting, and Participants: This cohort study used a pooled sample of cohorts of US youth (aged 12-17 years at their baseline and follow-up interviews) in the Population Assessment of Tobacco and Health Study (September 2013 to November 2019). Household interviews were conducted using audio computer-assisted self-interviews. US youth who were past-30-day cigarette smokers at any of wave 2 through wave 5, completed the preceding survey (eg, wave 2 past-30-day cigarette smokers completed wave 1), and indicated whether they used menthol cigarettes were eligible. The association of menthol use with smoking frequency and ND was estimated using inverse probability of treatment weighting adjusted mean differences (aMDs), adjusted risk ratios (aRRs), and corresponding 95% CIs. Data were analyzed from December 2021 to March 2022. Exposures: Menthol use and transitions in use (switching to or from menthol cigarettes). Main Outcomes and Measures: Main outcomes were the number of days smoked in the past 30 days, the risk of frequent smoking (smoking ≥20 days in the past 30 days), and symptoms of ND. Results: There were a total of 1492 observations among 1096 US youth cigarette smokers, of whom 49.4% were female, 67.2% were non-Hispanic White, and 28.7% were aged 12 to 14 years at their baseline survey (all percentages are weighted). Among those who switched from not smoking to smoking (61% of the sample), menthol use was associated with smoking on 3.1 additional days (aMD; 95% CI, 1.9 to 4.2 days), 59% higher risk of being a frequent smoker (aRR, 1.59; 95% CI, 1.23 to 2.06), and 10% higher ND scores (aMD, 1.09; 95% CI, 1.02 to 1.17). Switching from smoking menthol to smoking nonmenthol (vs maintaining menthol use) was associated with smoking on 3.6 fewer days (aMD; 95% CI, -6.3 to -0.9 days) and 47% lower risk of being a frequent smoker (aRR, 0.68; 95% CI, 0.50 to 0.92). Conclusions and Relevance: These findings suggest that the addition of menthol to cigarettes is associated with increased smoking frequency and ND among US youth.

Daily E-cigarette Use and the Surge in JUUL Sales: 2017-2019.

OBJECTIVES: To identify how the 2017 rapid surge in sales of JUUL e-cigarettes affected usage among US youth and young adults. METHODS: Annual surveys in the Population Assessment of Tobacco and Health Study assess tobacco use by product and brand among the US population. We identified 2 cohorts aged 14 to 34 years, 1 with baseline survey in 2014 before the rapid surge of JUUL and the other in 2017 as the surge in JUUL sales was occurring. For 5 age groups, we compared 2-year incidence of first tobacco use and of new-onset daily tobacco use by product, and report levels of dependence. RESULTS: Sociodemographic variables and rates of experimentation with any tobacco product were similar between cohorts. Among baseline nondaily tobacco users, only those aged 14 to 17 years had an increase in the 2-year incidence of new daily tobacco use (2014 cohort = 4.8%, 95% confidence interval 4.3, 5.5 vs 2017 cohort = 6.3%, 95% confidence interval 5.8-7.0) to rates approaching those in the 1990s. In 2019, three-quarters of new daily tobacco users aged 14 to 17 vaped daily and had e-cigarette dependence scores similar to daily cigarette smokers and older adult e-cigarette vapers. We estimate that about 600 000 Americans aged <21 years used JUUL products daily in 2019, a rate 2.5 times those aged 25 to 34 years. CONCLUSIONS: The surge in US JUUL sales was associated with a sharp rise in daily e-cigarette vaping and daily tobacco use among US youth, not young adults.