Association of cigarette and electronic cigarette use patterns with all-cause mortality: A national cohort study of 145,390 US adults.

OBJECTIVE: While e-cigarette use is associated with adverse cardiopulmonary health effects, the mortality risks associated with e-cigarette use alone and combined with smoking remain unexamined. METHODS: Data between 2014 and 2018 were obtained from the National Health Interview Survey (NHIS), an annual cross-sectional survey of US adults. All-cause mortality and date of death were obtained via linkage of the NHIS to the National Death Index through December 31, 2019. A 6-category composite cigarette (never, former, current) and e-cigarette (current, non-current) exposure variable was created. We examined the association of cigarette and e-cigarette use patterns with all-cause mortality using adjusted Cox models. RESULTS: Among 145,390 participants (79,294 women [51.5%]; 60,560 aged 18-44 [47.4%]), 5220 deaths were observed over a median follow-up of 3.5 years (508,545 total person-years). Dual use of cigarettes and e-cigarettes was associated with higher mortality risk compared with non-current e-cigarette use in combination with never smoking (hazard ratio [HR] 2.44; 95% CI, 1.90-3.13) and had a risk that did not differ from current exclusive smoking (HR, 1.06; 95% CI, 0.83-1.37). Current e-cigarette use in combination with former smoking was associated with a lower mortality risk than current exclusive cigarette smoking (HR 0.64; 95% CI, 0.41-0.99). CONCLUSIONS: The addition of e-cigarette use to smoking does not reduce mortality risk compared with exclusive smoking. However, transitioning completely from cigarettes to e-cigarettes may be associated with mortality risk reduction. Further research is needed to verify these findings in larger cohorts and over longer periods of follow-up.

Sociodemographic Differences in E-Cigarette Uptake and Perceptions of Harm.

INTRODUCTION: This study aimed to evaluate socioeconomic and racial/ethnic differences in e-cigarette uptake and harm perceptions about e-cigarettes among adults who smoke cigarettes in the U.S. METHODS: Five waves of the U.S. Population Assessment of Tobacco and Health Study (2013-2019) were used to assess transitions from exclusive cigarette smoking to (1) exclusive e-cigarette use, (2) dual use, and (3) nonuse of either product (N=7,172). Analyses (conducted in 2022) estimated differences in transitions and e-cigarette harm perceptions by race/ethnicity, income, and education. RESULTS: Hispanic (OR=0.32; 95% CI=0.18, 0.54) and Black (OR=0.38; 95% CI=0.22, 0.65) adults were less likely than White adults to transition from exclusive cigarette to exclusive e-cigarette use after 1 year. Adults with a bachelor's degree (versus those with less than high school) (OR=2.57; 95% CI=1.49, 4.45) and adults making ≥$100,000/year (versus those making <$10,000) (OR=3.61; 95% CI=2.10, 6.22) were more likely to transition from exclusive cigarette to exclusive e-cigarette use. Hispanic and Black adults and those with lower income and education were more likely to perceive e-cigarettes as equally or more harmful than cigarettes, which in turn was associated with lower odds of transitioning from exclusive cigarette smoking to exclusive e-cigarette use (OR=0.62; 95% CI=0.47, 0.81). CONCLUSIONS: Adults who were Hispanic, were Black, and/or had lower SES were less likely to use e-cigarettes to quit cigarettes. Findings provide preliminary evidence that differences in harm perceptions may contribute to disparities in e-cigarette transitions.

Cigarette‒E-cigarette Transitions and Respiratory Symptom Development.

INTRODUCTION: E-cigarette use is associated with pulmonary inflammation, functional respiratory changes, and chronic lung disease. Most population-level E-cigarette research has utilized point-in-time measures of E-cigarette exposures, which may not generalize to adults who transition between cigarettes and E-cigarettes. METHODS: Data obtained from the Population Assessment of Tobacco and Health study were collected from 2013 to 2019 and analyzed in 2022. Three observations were created per respondent, with exposure intervals assessed over Waves 1-2, 2-3, and 3-4. Each wave of the exposure interval was classified as nonuse, exclusive E-cigarette use, exclusive smoking, or dual use, producing 16 possible cigarette‒E-cigarette transitions. The association between transitions and both dry nighttime cough and wheeze symptom development during follow-up were assessed using mixed-effects Poisson models. RESULTS: Among 33,231 observations from 13,528 unique participants, transitioning from nonuse to exclusive E-cigarette use was associated with 1.62 times higher incidence rate of wheeze (incident rate ratio=1.62; 95% CI=1.12, 2.34) than persistent nonuse. There was no change in reported dry nighttime cough (incident rate ratio=0.84; 95% CI=0.52, 1.35) or wheeze (incident rate ratio=0.87; 95% CI=0.52, 1.46) in individuals who switched from cigarettes to E-cigarettes, whereas transitioning from dual use to E-cigarette use was associated with large reductions in both symptoms (incident rate ratio=0.58; 95% CI=0.39, 0.87 and incident rate ratio=0.36; 95% CI=0.20, 0.63, respectively). CONCLUSIONS: E-cigarette initiation among nonusers is associated with increased respiratory morbidity. Further research should assess the risks and benefits of E-cigarette‒assisted cigarette cessation given the reduction in symptom development rates among dual use to E-cigarette switchers.

Association of Electronic Cigarette Use with Respiratory Symptom Development among U.S. Young Adults.

Rationale: Electronic cigarette (e-cigarette) use is highly prevalent among young adults. However, longitudinal data assessing the association between e-cigarette use and respiratory symptoms are lacking. Objectives: To determine whether e-cigarette use is associated with the development of respiratory symptoms in young adults. Methods: Data are derived from the PATH (Population Assessment of Tobacco and Health) study waves 2 (2014-2015), 3 (2015-2016), 4 (2016-2018), and 5 (2018-2019). Young adults aged 18-24 years at baseline with no prevalent respiratory disease or symptoms were included in the analyses. Binary logistic regression models with a generalized estimating equation were used to estimate time-varying and time-lagged associations of e-cigarette use during waves 2-4, with respiratory symptom development approximately 12 months later at waves 3-5. Measurements and Main Results: The per-wave prevalence of former and current e-cigarette use was 15.2% and 5.6%, respectively. Former e-cigarette use was associated with higher odds of developing any respiratory symptom (adjusted odds ratio [aOR], 1.20; 95% confidence interval [CI], 1.04-1.39) and wheezing in the chest (aOR, 1.41; 95% CI, 1.08-1.83) in multivariable adjusted models. Current e-cigarette use was associated with higher odds for any respiratory symptom (aOR, 1.32; 95% CI, 1.06-1.65) and wheezing in the chest (aOR, 1.51; 95% CI, 1.06-2.14). Associations persisted among participants who never smoked combustible cigarettes. Conclusions: In this nationally representative cohort of young adults, former and current e-cigarette use was associated with higher odds of developing wheezing-related respiratory symptoms, after accounting for cigarette smoking and other combustible tobacco product use.