Causes of and Clinical Features Associated with Death in Tobacco Cigarette Users by Lung Function Impairment.

Rationale: Cigarette smoking contributes to the risk of death through different mechanisms. Objectives: To determine how causes of and clinical features associated with death vary in tobacco cigarette users by lung function impairment. Methods: We stratified current and former tobacco cigarette users enrolled in Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) into normal spirometry, PRISm (Preserved Ratio Impaired Spirometry), Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1-2 COPD, and GOLD 3-4 COPD. Deaths were identified via longitudinal follow-up and Social Security Death Index search. Causes of death were adjudicated after a review of death certificates, medical records, and next-of-kin interviews. We tested associations between baseline clinical variables and all-cause mortality using multivariable Cox proportional hazards models. Measurements and Main Results: Over a 10.1-year median follow-up, 2,200 deaths occurred among 10,132 participants (age 59.5 ± 9.0 yr; 46.6% women). Death from cardiovascular disease was most frequent in PRISm (31% of deaths). Lung cancer deaths were most frequent in GOLD 1-2 (18% of deaths vs. 9-11% in other groups). Respiratory deaths outpaced competing causes of death in GOLD 3-4, particularly when BODE index ⩾7. St. George's Respiratory Questionnaire score ⩾25 was associated with higher mortality in all groups: Hazard ratio (HR), 1.48 (1.20-1.84) normal spirometry; HR, 1.40 (1.05-1.87) PRISm; HR, 1.80 (1.49-2.17) GOLD 1-2; HR, 1.65 (1.26-2.17) GOLD 3-4. History of respiratory exacerbations was associated with higher mortality in GOLD 1-2 and GOLD 3-4, quantitative emphysema in GOLD 1-2, and airway wall thickness in PRISm and GOLD 3-4. Conclusions: Leading causes of death vary by lung function impairment in tobacco cigarette users. Worse respiratory-related quality of life is associated with all-cause mortality regardless of lung function.

Smoking Cessation, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology.

Although the harmful effects of smoking after a cancer diagnosis have been clearly demonstrated, many patients continue to smoke cigarettes during treatment and beyond. The NCCN Guidelines for Smoking Cessation emphasize the importance of smoking cessation in all patients with cancer and seek to establish evidence-based recommendations tailored to the unique needs and concerns of patients with cancer. The recommendations contained herein describe interventions for cessation of all combustible tobacco products (eg, cigarettes, cigars, hookah), including smokeless tobacco products. However, recommendations are based on studies of cigarette smoking. The NCCN Smoking Cessation Panel recommends that treatment plans for all patients with cancer who smoke include the following 3 tenets that should be done concurrently: (1) evidence-based motivational strategies and behavior therapy (counseling), which can be brief; (2) evidence-based pharmacotherapy; and (3) close follow-up with retreatment as needed.

Longitudinal associations between exclusive, dual, and polytobacco use and asthma among US youth.

Little is known about the respiratory health effects of dual (two products) and polytobacco (three or more products) use among youth in the United States. Thus, we followed a longitudinal cohort of youth into adulthood using data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study, examining incident asthma at each follow-up (Waves 2-5). We classified past 30-day tobacco use as 1) no products (never/former use), 2) exclusive cigarettes, 3) exclusive electronic nicotine delivery systems (ENDS), 4) exclusive other combustible (OC) tobacco products (cigars, hookah, pipe), 5) dual cigarettes/OC and ENDS, 6) dual cigarettes and OCs, and 7) polytobacco use (cigarettes, OCs, and ENDS). Using discrete time survival models, we analyzed the incidence of asthma across Waves 2-5, predicted by time-varying tobacco use lagged by one wave, and adjusted for potential baseline confounders. Asthma was reported by 574 of the 9141 respondents, with an average annual incidence of 1.44% (range 0.35% to 2.02%, Waves 2-5). In adjusted models, exclusive cigarette use (HR: 1.71, 95% CI: 1.11-2.64) and dual cigarette and OC use (HR: 2.78, 95% CI: 1.65-4.70) were associated with incident asthma compared to never/former use, while exclusive ENDS use (HR: 1.50, 95% CI: 0.92-2.44) and polytobacco use (HR: 1.95, 95% CI: 0.86-4.44) were not. To conclude, youth who use cigarettes with or without OCs had higher risk of incident asthma. Further longitudinal studies on the respiratory health effects of ENDS and dual/polytobacco use are needed as products continue to evolve.

Longitudinal Associations Between Exclusive and Dual Use of Electronic Nicotine Delivery Systems and Cigarettes and Self-Reported Incident Diagnosed Cardiovascular Disease Among Adults.

INTRODUCTION: The cardiovascular health effects of electronic nicotine delivery systems (ENDS) use are not well characterized, making it difficult to assess ENDS as a potential harm reduction tool for adults who use cigarettes. AIMS AND METHODS: Using waves 1-5 of the Population Assessment of Tobacco and Health Study (2013-2019), we analyzed the risk of self-reported incident diagnosed myocardial infarction (MI; 280 incident cases) and stroke (186 incident cases) associated with ENDS and/or cigarette use among adults aged 40 + using discrete time survival models. We employed a time-varying exposure lagged by one wave, defined as exclusive or dual established use of ENDS and/or cigarettes every day or some days, and controlled for demographics, clinical factors, and past smoking history. RESULTS: The analytic samples (MI = 11 031; stroke = 11 076) were predominantly female and non-Hispanic White with a mean age of 58 years. At baseline, 14.2% of respondents exclusively smoked cigarettes, 0.6% exclusively used ENDS, and 1.0% used both products. Incident MI and stroke were rare during follow-up (< 1% at each wave). Compared to no cigarette or ENDS use, exclusive cigarette use increased the risk of MI (aHR 1.99, 95% CI = 1.40-2.84) and stroke (aHR 2.26, 95% CI = 1.51-3.39), while exclusive ENDS use (MI: aHR 0.61, 95% CI = 0.12-3.04; stroke: aHR 1.74, 95% CI = 0.55-5.49) and dual use (MI: aHR 1.84, 95% CI = 0.64-5.30; stroke: aHR 1.12, 95% CI = 0.33-3.79) were not significantly associated with the risk of either outcome. CONCLUSIONS: Compared to non-use, exclusive cigarette use was associated with an increased risk of self-reported incident diagnosed cardiovascular disease over a 5-year period, while ENDS use was not associated with a statistically significant increase in the outcomes. IMPLICATIONS: Existing literature on the health effects of ENDS use has important limitations, including potential reverse causation and improper control for cigarette smoking. We accounted for these issues by using a prospective design and adjusting for current and former smoking status and cigarette pack-years. In this context, we did not find that ENDS use was associated with a statistically significant increase in self-reported incident diagnosed myocardial infarction or stroke over a 5-year period. While more studies are needed, this analysis provides an important foundation and key methodological considerations for future research on the health effects of ENDS use.

Treatment capacity required for full-scale implementation of lung cancer screening in the United States.

BACKGROUND: Full-scale implementation of lung cancer screening in the United States will increase detection of early stages. This study was aimed at assessing the capacity required for treating those cancers. METHODS: A well-established microsimulation model was extended with treatment data from the National Cancer Database. We assessed how treatment demand would change when implementing lung cancer screening in 2018. Three policies were assessed: 1) annual screening of current smokers and former smokers who quit fewer than 15 years ago, aged 55 to 80 years, with a smoking history of at least 30 pack-years (US Preventive Services Task Force [USPSTF] recommendations); 2) annual screening of current smokers and former smokers who quit fewer than 15 years ago, aged 55 to 77 years, with a smoking history of at least 30 pack-years (Centers for Medicare and Medicaid Services [CMS] recommendations); and 3) annual screening of current smokers and former smokers who quit fewer than 10 years ago, aged 55 to 75 years, with a smoking history of at least 40 pack-years (the most cost-effective policy in Ontario [Ontario]). The base-case screening adherence was a constant 50%. Sensitivity analyses assessed other adherence levels, including a linear buildup to 50% between 2018 and 2027. RESULTS: The USPSTF policy would require 37.0% more lung cancer surgeries in 2015-2040 than no screening, 2.2% less radiotherapy, and 5.4% less chemotherapy; 5.7% more patients would require any therapy. The increase in surgical demand would be 96.1% in 2018, 46.0% in 2023, 38.3% in 2028, and 24.9% in 2040. Adherence strongly influenced results. By 2018, surgical demand would range from 52,619 (20% adherence) to 96,121 (80%). With a gradual buildup of adherence, the increase in surgical demand would be 9.6% in 2018, 38.3% in 2023, 42.0% in 2028, and 24.4% in 2040. Results for the CMS and Ontario policies were similar, although the changes in comparison with no screening were smaller. CONCLUSIONS: Full-scale implementation of lung cancer screening causes a major increase in surgical demand, with a peak within the first 5 years. A gradual buildup of adherence can spread this peak over time. Careful surgical capacity planning is essential for successfully implementing screening.

RNAseq analysis of bronchial epithelial cells to identify COPD-associated genes and SNPs.

BACKGROUND: There is a need for more powerful methods to identify low-effect SNPs that contribute to hereditary COPD pathogenesis. We hypothesized that SNPs contributing to COPD risk through cis-regulatory effects are enriched in genes comprised by bronchial epithelial cell (BEC) expression patterns associated with COPD. METHODS: To test this hypothesis, normal BEC specimens were obtained by bronchoscopy from 60 subjects: 30 subjects with COPD defined by spirometry (FEV1/FVC < 0.7, FEV1% < 80%), and 30 non-COPD controls. Targeted next generation sequencing was used to measure total and allele-specific expression of 35 genes in genome maintenance (GM) genes pathways linked to COPD pathogenesis, including seven TP53 and CEBP transcription factor family members. Shrinkage linear discriminant analysis (SLDA) was used to identify COPD-classification models. COPD GWAS were queried for putative cis-regulatory SNPs in the targeted genes. RESULTS: On a network basis, TP53 and CEBP transcription factor pathway gene pair network connections, including key DNA repair gene ERCC5, were significantly different in COPD subjects (e.g., Wilcoxon rank sum test for closeness, p-value = 5.0E-11). ERCC5 SNP rs4150275 association with chronic bronchitis was identified in a set of Lung Health Study (LHS) COPD GWAS SNPs restricted to those in putative regulatory regions within the targeted genes, and this association was validated in the COPDgene non-hispanic white (NHW) GWAS. ERCC5 SNP rs4150275 is linked (D' = 1) to ERCC5 SNP rs17655 which displayed differential allelic expression (DAE) in BEC and is an expression quantitative trait locus (eQTL) in lung tissue (p = 3.2E-7). SNPs in linkage (D' = 1) with rs17655 were predicted to alter miRNA binding (rs873601). A classifier model that comprised gene features CAT, CEBPG, GPX1, KEAP1, TP73, and XPA had pooled 10-fold cross-validation receiver operator characteristic area under the curve of 75.4% (95% CI: 66.3%-89.3%). The prevalence of DAE was higher than expected (p = 0.0023) in the classifier genes. CONCLUSIONS: GM genes comprised by COPD-associated BEC expression patterns were enriched for SNPs with cis-regulatory function, including a putative cis-rSNP in ERCC5 that was associated with COPD risk. These findings support additional total and allele-specific expression analysis of gene pathways with high prior likelihood for involvement in COPD pathogenesis.

Smoking Cessation, Version 1.2016, NCCN Clinical Practice Guidelines in Oncology.

Cigarette smoking has been implicated in causing many cancers and cancer deaths. There is mounting evidence indicating that smoking negatively impacts cancer treatment efficacy and overall survival. The NCCN Guidelines for Smoking Cessation have been created to emphasize the importance of smoking cessation and establish an evidence-based standard of care in all patients with cancer. These guidelines provide recommendations to address smoking in patients and outlines behavioral and pharmacologic interventions for smoking cessation throughout the continuum of oncology care.

An official American Thoracic Society/American College of Chest Physicians policy statement: implementation of low-dose computed tomography lung cancer screening programs in clinical practice.

RATIONALE: Annual low-radiation-dose computed tomography (LDCT) screening for lung cancer has been shown to reduce lung cancer mortality among high-risk individuals and is now recommended by multiple organizations. However, LDCT screening is complex, and implementation requires careful planning to ensure benefits outweigh harms. Little guidance has been provided for sites wishing to develop and implement lung cancer screening programs. OBJECTIVES: To promote successful implementation of comprehensive LDCT screening programs that are safe, effective, and sustainable. METHODS: The American Thoracic Society (ATS) and American College of Chest Physicians (ACCP) convened a committee with expertise in lung cancer screening, pulmonary nodule evaluation, and implementation science. The committee reviewed the evidence from systematic reviews, clinical practice guidelines, surveys, and the experience of early-adopting LDCT screening programs and summarized potential strategies to implement LDCT screening programs successfully. MEASUREMENTS AND MAIN RESULTS: We address steps that sites should consider during the main three phases of developing an LDCT screening program: planning, implementation, and maintenance. We present multiple strategies to implement the nine core elements of comprehensive lung cancer screening programs enumerated in a recent ACCP/ATS statement, which will allow sites to select the strategy that best fits with their local context and workflow patterns. Although we do not comment on cost-effectiveness of LDCT screening, we outline the necessary costs associated with starting and sustaining a high-quality LDCT screening program. CONCLUSIONS: Following the strategies delineated in this policy statement may help sites to develop comprehensive LDCT screening programs that are safe and effective.

Endobronchial ultrasound-guided transbronchial needle aspiration for non-small cell lung cancer staging.

Real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established technique for invasive mediastinal staging of non-small cell lung cancer (NSCLC). Needle-based techniques are now recommended as a first-line diagnostic modality for mediastinal staging. Accurate performance of systematic staging with EBUS-TBNA requires a detailed knowledge of mediastinal anatomy. This examination begins at the N3 lymph nodes, progressing through the N2 and N1 lymph node stations, unless a higher station lymph node is positive for malignant cells by rapid on-site cytologic examination. Objective methods of identifying EBUS-TBNA targets include sampling any lymph node station with a visible lymph node or with a lymph node greater than 5 mm in short axis. Three passes per station or the use of rapid on-site cytologic examination with identification of diagnostic material (tumor or lymphocytes) up to five passes are well-established techniques. Obtaining sufficient tissue for molecular profiling may require performing more than three passes. The operating characteristics of EBUS-TBNA are similar to mediastinoscopy. However, mediastinoscopy should be considered in the setting of a negative EBUS-TBNA and a high posterior probability of N2 or N3 involvement.

Barriers to Timely Lung Cancer Care in Early Stage Non-Small Cell Lung Cancer and Impact on Patient Outcomes.

BACKGROUND: Optimal time to treatment for early-stage lung cancer is uncertain. We examined causes of delays in care for Veterans who presented with early-stage non-small cell lung cancer (NSCLC) and whether workup time was associated with increased upstaging or all-cause mortality. METHODS: We performed a retrospective analysis of Veterans referred to our facility with radiographic stage I or II NSCLC between January 2013 to December 2017, with follow-up through October 2021. Patient demographics, tumor characteristics, time intervals of care, and reasons for delays were collected. Guideline concordance (GC) was defined as treatment within 14 weeks of abnormal image. Multivariable analyses were performed to determine association between delays in care, survival, and upstaging. RESULTS: Data from 203 Veterans were analyzed. Median time between abnormal imaging to treatment was 17.7 weeks (IQR 12.7-26.6). Only 33% of Veterans received GC care. Most common patient-related delays were: intercurrent hospitalization/comorbidity (23%), no-shows (16%) and inability to reach Veteran (17%). Most common system-related delay: lack of scheduling availability (25%). Delays associated with upstaging: transportation issues, request for coordination of appointments, and unforeseen appointment changes. Rates of upstaging did not differ between GC and discordant groups (P = .6). GC care was not an independent predictor of mortality. Post-hoc, treatment within 8 weeks was associated with lower rates of upstaging (P = .05). CONCLUSION: Although GC care did not impact survival or upstaging for early-stage NSCLC, shorter timeframes may be beneficial. Modifiable delays in care exist which may be addressed at an institutional level to improve timeliness of care.

Longitudinal associations between exclusive, dual and polytobacco use and respiratory illness among youth.

Background: The health consequences of polytobacco use are still well not understand. We evaluated prospective associations between exclusive, dual, and polytobacco use and diagnosed bronchitis, pneumonia, or chronic cough among US youth. Methods: Data came from Waves 1-5 of the Population Assessment of Tobacco and Health Study. We categorized time-varying past 30-day tobacco use into seven categories: (1) non-current use; exclusive use of 2) cigarettes, 3) electronic nicotine delivery systems (ENDS), or 4) other combustible products (OC; pipes, hookah, and cigars); dual use of 5) ENDS + cigarettes or ENDS + OC 6) cigarettes + OC; or 7) polyuse of all three products. The outcome was incident diagnosis of bronchitis, pneumonia, or chronic cough. We conducted weighted multilevel Poisson models (person n = 17,517, 43,290 observations) to examine the longitudinal exposure-outcome relationship, adjusting for covariates: sex, age, race and ethnicity, parental education, body mass index, secondhand smoke exposure, and household use of combustible products. Results: Compared to nonuse, exclusive cigarette use (Incidence Rate Ratio (IRR) = 1.83, 95% CI 1.25-2.68), exclusive ENDS use (IRR = 1.53, 95% CI 1.08-2.15), combustible product + ENDS dual use (IRR = 1.90, 95% CI 1.18-3.04), cigarettes + OC dual use (IRR = 1.96, 95% CI 1.11-3.48), and polytobacco use (IRR = 3.06 95% CI 1.67-5.63) were associated with a higher incidence of bronchitis, pneumonia, or chronic cough. Conclusion: We found that exclusive, dual, and poly tobacco use was associated with higher incidence of bronchitis, pneumonia, or chronic cough; Moreover, the incidence rate ratio for polytobacco use was higher than the incidence rate ratio for exclusive use compared to non-current use.

Phase II Trial Assessing Toxicity of Personalized Response-Based Radiation Treatment in Patients with Locally Advanced Non-Small Cell Lung Cancer.

INTRODUCTION: Local failure rates after treatment for locally advanced non-small-cell lung cancer (NSCLC) remain high. Efforts to improve local control with uniform dose-escalation or dose-escalation to mid-treatment PET-avid residual disease have been limited by heightened toxicity. This trial aimed to refine response-based adaptive radiation (RT) and minimize toxicity by incorporating FDG-PET and V/Q SPECT imaging mid-treatment. METHODS: 47 patients with Stage IIA-III unresectable NSCLC were prospectively enrolled in this single-institution trial (NCT02492867). Patients received concurrent chemoradiation with personalized response-based adaptive RT over 30 fractions incorporating V/Q SPECT and FDG-PET. The first 21 fractions (46.2Gy at 2.2 Gy/fraction) were delivered to the tumor while minimizing dose to SPECT-defined functional lung. The plan was then adapted for the final 9 fractions (2.2-3.8Gy/fraction) up to a total of 80.4Gy, based on mid-treatment FDG-PET tumor response to escalate dose to residual tumor while minimizing dose to SPECT-defined functional lung. Non-progressing patients received consolidative carboplatin/paclitaxel or durvalumab. The primary endpoint of the study was ≥ grade 2 lung and esophageal toxicities. Secondary endpoints included time to local progression, tumor response, and overall survival. RESULTS: At one year post-treatment, the rates of grade 2 and grade 3 pneumonitis were 21.3% and 2.1%, respectively, with no difference in pneumonitis rates among patients who received and did not receive adjuvant durvalumab (p=0.74). While there were no grade 3 esophageal-related toxicities, 66.0% of patients experienced grade 2 esophagitis. 1- and 2-year local control rates were 94.5% (95% CI, 87.4% - 100%) and 87.5% (95% CI, 76.7% - 100%), respectively. Overall survival was 82.8% (95% CI, 72.6% -94.4%) at 1 year and 62.3% (95% CI, 49.6%-78.3%) at 2 years. CONCLUSIONS: Response-based adaptive dose-escalation accounting for tumor change and normal tissue function during treatment provided excellent local control, comparable toxicity to standard chemoradiation, and did not increase toxicity with adjuvant immunotherapy.

Lung CD8+ T cells in COPD have increased expression of bacterial TLRs.

BACKGROUND: Toll-like receptors (TLRs) on T cells can modulate their responses, however, the extent and significance of TLR expression by lung T cells, NK cells, or NKT cells in chronic obstructive pulmonary disease (COPD) is unknown. METHODS: Lung tissue collected from clinically-indicated resections (n = 34) was used either: (a) to compare the expression of TLR1, TLR2, TLR2/1, TLR3, TLR4, TLR5, TLR6 and TLR9 on lung CD8+ T cells, CD4+ T cells, NK cells and NKT cells from smokers with or without COPD; or (b) to isolate CD8+ T cells for culture with anti-CD3ε without or with various TLR ligands. We measured protein expression of IFN-γ, TNF-α, IL-13, perforin, granzyme A, granzyme B, soluble FasL, CCL2, CCL3, CCL4, CCL5, CCL11, and CXCL9 in supernatants. RESULTS: All the lung subsets analyzed demonstrated low levels of specific TLR expression, but the percentage of CD8+ T cells expressing TLR1, TLR2, TLR4, TLR6 and TLR2/1 was significantly increased in COPD subjects relative to those without COPD. In contrast, from the same subjects, only TLR2/1 and TLR2 on lung CD4+ T cells and CD8+ NKT cells, respectively, showed a significant increase in COPD and there was no difference in TLR expression on lung CD56+ NK cells. Production of the Tc1 cytokines IFN-γ and TNF-α by lung CD8+ T cells were significantly increased via co-stimulation by Pam3CSK4, a specific TLR2/1 ligand, but not by other agonists. Furthermore, this increase in cytokine production was specific to lung CD8+ T cells from patients with COPD as compared to lung CD8+ T cells from smokers without COPD. CONCLUSIONS: These data suggest that as lung function worsens in COPD, the auto-aggressive behavior of lung CD8+ T cells could increase in response to microbial TLR ligands, specifically ligands against TLR2/1.

Lung cancer screening.

The National Lung Screening Trial demonstrated that lung cancer screening with three annual low-dose computed tomographic scans has the potential to reduce lung cancer-specific mortality by 20% in an older population of heavy smokers. This was a great achievement by the National Lung Screening Trial (NLST) investigators, but this should be viewed as an important first step in an unfinished process. Many major questions remain about how to best realize this mortality reduction in a practical real-world context. Screening for lung cancer will be most effective if it is accompanied by continued research into risk modeling, patient communication strategies, and biomarkers. For clinicians establishing a program of lung cancer screening, we encourage this to be done in a responsible fashion, adhering to practices specified in the design of the NLST, and with careful attention given to proper management of screen-detected abnormalities and maintenance of screening registries.

Temporal Trends and Variation in Bronchoscopy Use for Acute Respiratory Failure in the United States.

BACKGROUND: National data on bronchoscopy for the evaluation of acute respiratory failure are lacking, and the limited available data suggest wide variation in use. RESEARCH QUESTION: How commonly is bronchoscopy performed among hospitalizations with acute respiratory failure? How has use changed over time and across hospitals? STUDY DESIGN AND METHODS: This was an observational cohort study of adult hospitalizations (2012-2018) treated with invasive mechanical ventilation (IMV) using the National Inpatient Sample, which represents 97% of all hospitalizations in the United States. We measured the proportion of hospitalizations treated with IMV who underwent bronchoscopy and assessed trends in bronchoscopy use over time. Multilevel linear regression models were used to quantify hospital-level variation, adjusting for differences in patient and hospital characteristics. RESULTS: We identified 6,101,070 IMV-treated hospitalizations (2012-2018), of whom 609,405 underwent bronchoscopy; among hospitalizations receiving bronchoscopy, mean age was 61 years, 41.8% were women, and in-hospital mortality was 30.8%. The percentage of IMV-treated hospitalizations receiving bronchoscopy increased from 9.5% (95% CI, 9.1%-9.9%) in 2012 to 10.8% (95% CI, 10.4%-11.2%) in 2018 (P < .001 for difference). In 2018, bronchoscopy use varied from 0% to 57.1% among 1,787 hospitals, and in multilevel models adjusted for patient and hospital characteristics, 16.0% of the variation was explained at the hospital level. The median OR was 2.13 (95% CI, 2.05-2.21), indicating 113% increased odds of receiving bronchoscopy if moving from a lower-use to a higher-use hospital. INTERPRETATION: Bronchoscopy use among hospitalizations treated with IMV has increased over time. The large variation in use of bronchoscopy across hospitals suggests potentially unwarranted practice variation and need for further studies to clarify which patients benefit from bronchoscopy.

Longitudinal Association Between Exclusive and Dual Use of Cigarettes and Electronic Nicotine Delivery Systems and Asthma Among U.S. Adolescents.

PURPOSE: Electronic Nicotine Delivery Systems (ENDS) use among adolescents has increased greatly over the past decade, but its impact on chronic respiratory health conditions, like asthma, is not fully understood. METHODS: We examined data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study using discrete time hazard models to analyze the association between time-varying tobacco product use and incident diagnosed asthma among adolescents aged 12-17 years at baseline. We lagged the time-varying exposure variable by one wave and categorized respondents by current use status (1+ days in the past 30 days): never or non-current, exclusive cigarette, exclusive ENDS, and dual cigarette and ENDS use. We also controlled for sociodemographic (age, sex, race/ethnicity, parental education) and other risk factors (urban/rural setting, secondhand smoke exposure, household combustible tobacco use, body mass index). RESULTS: At baseline, over half the analytic sample (n = 9,141) was 15-17 years old (50.4%), female (50.2%), and non-Hispanic White (55.3%). Adolescents who exclusively smoked cigarettes had a statistically significant higher risk of incident diagnosed asthma at follow-up (adjusted Hazard Ratio (aHR): 1.68, 95% confidence interval (CI): 1.21-2.32) compared to those not currently using cigarettes or ENDS, but adolescents using ENDS exclusively (aHR: 1.25, 95% CI: 0.77-2.04) or in combination with cigarettes (aHR: 1.54, 95% CI: 0.92-2.57) did not. DISCUSSION: Short-term exclusive cigarette use was associated with a higher risk of incident diagnosed asthma over five years of follow-up among adolescents. We did not find conclusive evidence for an association between exclusive ENDS or dual use and incident diagnosed asthma.

Cigarettes, ENDS Use, and Chronic Obstructive Pulmonary Disease Incidence: A Prospective Longitudinal Study.

INTRODUCTION: Understanding the relationship between ENDS use and chronic obstructive pulmonary disease (COPD) and other respiratory conditions is critical. However, most previous studies have not fully adjusted for cigarette smoking history. METHODS: Using Waves 1-5 of the U.S. Population Assessment of Tobacco and Health study, the association between ENDS use and self-reported incident COPD was examined among adults aged 40+ years using discrete-time survival models. Current ENDS use was measured as a time-varying covariate, lagged by 1 wave, defined as established daily or some days of use. Multivariable models were adjusted for baseline demographics (age, sex, race/ethnicity, education), health characteristics (asthma, obesity, exposure to second-hand smoke), and smoking history (smoking status and cigarette pack years). Data were collected between 2013 and 2019, and the analysis was conducted in 2021-2022. RESULTS: Incident COPD was self-reported by 925 respondents during the 5-year follow-up. Before adjusting for other covariates, time-varying ENDS use appeared to double COPD incidence risk (hazard ratio=1.98, 95% CI=1.44, 2.74). However, ENDS use was no longer associated with COPD (adjusted hazard ratio=1.10, 95% CI=0.78, 1.57) after adjusting for current cigarette smoking and cigarette pack years. CONCLUSIONS: ENDS use did not significantly increase the risk of self-reported incident COPD over a 5-year period once current smoking status and cigarette pack years were included. Cigarette pack years, by contrast, remained associated with a net increase in COPD incidence risk. These findings highlight the importance of using prospective longitudinal data and adequately controlling for cigarette smoking history to assess the independent health effects of ENDS.