INTRODUCTION E-cigarettes have been steadily increasing in popularity, both as cessation methods for smoking and for recreational and social reasons. This increase in vaping may pose cardiovascular and respiratory risks. We aimed to assess respiratory symptoms in youth users of e-cigarettes and cigarettes. METHODS A retrospective survey design was utilized to assess Canadian youth aged 16–25 years. Participants were recruited from the Ontario Tobacco Research Unit Youth and Young Adult Research Registration Panel November 2020 to March 2021. A total of 3082 subjects completed the baseline survey. Of these, 2660 individuals who did not have asthma were included in the analysis. The exposure of interest was pack-equivalent years, a novel measure of vaping exposure equivalent conceptually to cigarette pack years incorporating number of puffs per day, number of days vaped per month, and number of years vaped. Respiratory symptoms were measured using the five-item Canadian Lung Health Test. Poisson regression analyses were performed while adjusting for demographic confounders, stratified by smoking status. A non-stratified model tested the interaction of status and vaping dose and the effect of vaping device used was assessed among ever vapers. Analyses controlled for demographic characteristics, use of cannabis and alcohol, and survey date. RESULTS Each additional puff year increased the rate ratio (RR) of respiratory symptoms by a factor of 11.36 (95% CI: 4.61–28.00; p<0.001) for never smokers, but among current daily smokers higher pack-equivalent years were not associated with more respiratory symptoms (RR=0.83; 95% CI: 0.23–3.11). Among current vapers, those using pod-style devices were more likely to have more respiratory symptoms (RR=1.25; 95% CI: 1.08–1.45) after adjusting for dose. CONCLUSIONS Vaping is associated with an increased risk of reporting respiratory symptoms among never smoking youth and non-daily ever cigarette smokers. Use of e-cigarettes among non-smokers should be discouraged.

Introduction The majority of e-cigarette vaping youth use nicotine when vaping. Some then become dependent on the nicotine, which can result in subsequent health effects. There has been limited evaluation of convergent validity of e-cigarette dependence measures for use specifically in youth. The aim of this study was to investigate and validate various e-cigarette dependence measures for use in youth populations. Methods 1,205 Canadian youth aged 16-24 who completed a cross-sectional online survey reported vaping at least monthly and were thus included in the analysis. E-cigarette dependence was assessed using a modified Penn-State Electronic Cigarette Dependence Index (PS-ECDI), the E-Cigarette Dependence Scale (EDS), a self-perceived vaping dependence question, and time to first vape after waking. Internal consistency, convergent validity, and concurrent validity of the measures were assessed. Results Both the PS-ECDI and the EDS exhibited a good degree of internal consistency (α= 0.8472 and 0.8405, respectively). All measures exhibited convergent validity against each other and against time to first vape upon waking (p&lt;0.001), as well as concurrent validity against vaping frequency and nicotine concentration (p&lt;0.001). The PS-ECDI was inferior to the EDS, self-perceived measure, and time from waking when predicting daily vaping frequency, but, along with the self-perceived measure, was superior to the EDS and time from waking when predicting monthly vaping. Conclusions All measures exhibit convergent and concurrent validity, as well as internal consistency. Depending on the needs of the study, it would be appropriate to use any of these measures when assessing e-cigarette dependence in adolescent and young adult populations. Implications The PS-ECDI and the self-perceived measure are equally effective in predicting monthly vaping, but the self-perceived measure was superior in predicting daily vaping. Thus, the one-item self-perceived measure of dependence is appropriate for use and preferable to the 11-item PS-ECDI or the 4-item EDS in situations of limited time or where subjects are at risk of respondent fatigue, and is superior to time to first vape after waking to predict vaping frequency.

Introduction E-cigarettes have been steadily increasing in popularity, both as cessation methods for smoking and for recreational and social reasons. This increase in vaping may pose cardiovascular and respiratory risks. We aimed to assess respiratory symptoms in youth users of e-cigarettes and cigarettes. Methods A cross-sectional survey design was utilized to assess Canadian youth aged 16-25 years old. Participants were recruited from the Ontario Tobacco Research Unit Youth and Young Adult Research Registration Panel November 2020 to March 2021. A total of 3,082 subjects completed the baseline survey. Of these, 2660 individuals who did not have asthma were included in the analysis. The exposure of interest was vaping dose, pack equivalent years, equivalent to cigarette pack years incorporating number of puffs per day, number of days vaped per month, and number of years vaped. Respiratory symptoms were measured using the five-item Canadian Lung Health Test. Poisson regression analyses were performed while adjusting for demographic confounders, stratified by smoking status. A non-stratified model tested the interaction of status and vaping dose and the effect of vaping device used was assessed among ever vapers. Analyses controlled for demographic characteristics, use of cannabis and alcohol, and survey date. Results Each additional puff year increased the rate ratio of respiratory symptoms by a factor of 11.36 (95%CI: 4.61-28.00; p<0.001) for never smokers, but among current daily smokers higher pack equivalent years were not associated with more respiratory symptoms (0.83; 95% CI: 0.23., 3.11). Among current vapers, those using pod-style devices were more likely to have more respiratory symptoms (1.25; 95% CI: 1.08, 1.45) after adjusting for dose. Conclusions Vaping is associated with an increased risk of reporting respiratory symptoms among never smoking youth and non-daily ever cigarette smokers. Use of e-cigarettes among non-smokers should be discouraged.

Background Tobacco use is a major risk factor for developing head and neck squamous cell carcinoma (HNSCC). However, the prognostic associations with smoking cessation are limited. The authors assessed whether smoking cessation and increased duration of abstinence were associated with improved overall (OS) and HNSCC‐specific survival. Methods Clinicodemographic and smoking data from patients with HNSCC at Princess Margaret Cancer Center (2006–2019) were prospectively collected. Multivariable Cox and Fine and Gray competing‐risk models were used to assess the impact of smoking cessation and duration of abstinence on overall mortality and HNSCC‐specific/noncancer mortality, respectively. Results Among 2482 patients who had HNSCC, former smokers (adjusted hazard ratio [aHR], 0.71; 95% CI, 0.58–0.87; p = .001; N = 841) had a reduced risk of overall mortality compared with current smokers (N = 931). Compared with current smokers, former smokers who quit >10 years before diagnosis (long‐term abstinence; n = 615) had the most improved OS (aHR, 0.72; 95% CI, 0.56–0.93; p = .001). The 5‐year actuarial rates of HNSCC‐specific and noncancer deaths were 16.8% and 9.4%, respectively. Former smokers (aHR, 0.71; 95% CI, 0.54–0.95; p = .019) had reduced HNSCC‐specific mortality compared with current smokers, but there was no difference in noncancer mortality. Abstinence for >10 years was associated with decreased HNSCC‐specific death compared with current smoking (aHR, 0.64; 95% CI, 0.46–0.91; p = .012). Smoking cessation with a longer duration of quitting was significantly associated with reduced overall and HNSCC‐specific mortality in patients who received primary radiation. Conclusions Smoking cessation before the time of diagnosis reduced overall mortality and cancer‐specific mortality among patients with HNSCC, but no difference was observed in noncancer mortality. Long‐term abstinence (>10 pack‐years) had a significant OS and HNSCC‐specific survival benefit.