Introduction: Electronic cigarettes (e-cigs) are becoming increasingly popular, but little is known about their dependence potential. This study aimed to assess ratings of dependence on electronic cigarettes and retrospectively compare them with rated dependence on tobacco cigarettes among a large sample of ex-smokers who switched to e-cigs. Methods: A total of 3,609 current users of e-cigs who were ex-cigarette smokers completed a 158-item online survey about their e-cig use, including 10 items designed to assess their previous dependence on cigarettes and 10 almost identical items, worded to assess their current dependence on e-cigs (range 0-20). Results: Scores on the 10-item Penn State (PS) Cigarette Dependence Index were significantly higher than on the comparable PS Electronic Cigarette Dependence Index (14.5 vs. 8.1, p < .0001). In multivariate analysis, those who had used e-cigs longer had higher e-cig dependence scores, as did those using more advanced e-cigs that were larger than a cigarette and had a manual button. Those using zero nicotine liquid had significantly lower e-cig dependence scores than those using 1-12 mg/ml, who scored significantly lower than those using 13 or greater mg/ml nicotine liquid (p < .003). Conclusions: Current e-cigarette users reported being less dependent on e-cigarettes than they retrospectively reported having been dependent on cigarettes prior to switching. E-cig dependence appears to vary by product characteristics and liquid nicotine concentration, and it may increase over time.

Introduction: Electronic cigarettes (e-cigs) are becoming increasingly popular but little is known about how e-cig users' transition between the different device types and what device characteristics and preferences may influence the transition. Methods: Four thousand four hundred twenty-one experienced e-cig users completed an online survey about their e-cig use, devices, and preferences. Participants included in analysis were ever cigarette smokers who used an e-cig at least 30 days in their lifetime and who reported the type of their first and current e-cig device and the nicotine concentration of their liquid. Analyses focused on transitions between "first generation" devices (same size as a cigarette with no button) and "advanced generation" devices (larger than a cigarette with a manual button) and differences between current users of each device type. Results: Most e-cig users (n = 2603, 58.9%) began use with a first generation device, and of these users, 63.7% subsequently transitioned to current use of an advanced generation device. Among users who began use with an advanced generation device (n = 1818, 41.1%), only 5.7% transitioned to a first generation device. Seventy-seven percent of current advanced generation e-cig users switched to their current device in order to obtain a "more satisfying hit. " Battery capabilities and liquid flavor choices also influenced device choice. Conclusion: E-cig users commonly begin use with a device shaped like a cigarette and transition to a larger device with a more powerful battery, a button for manual activation and a wider choice of liquid flavors.

Background Awareness and use of electronic cigarettes (e-cigs) has increased significantly in the last five years, but little is known about the experiences, satisfaction, opinions and preferences of e-cigs users. Method 1177 participants completed an online survey about their electronic cigarette preferences, of which 200 were randomly selected for analysis. The data was analyzed using both qualitative and quantitative methods. Results Participants found the design, the ability to customize, and the quality of vapor to be the most important characteristics of the device. Participants thought the most positive aspects of e-cig use were help to quit smoking, improved overall health, and reduced cost. The negative aspects associated with use were mainly related to side effects, such as dry mouth. When asked to explain how e-cigs were used differently than cigarettes, participants reported puffing more regularly, but taking fewer puffs per session. Conclusions Experienced e-cig users stated that initiating e-cig use helped them to quit or reduce their conventional smoking, which they believe reduced their health risks. In comparison to cigarette smoking, e-cig users reported using their e-cig more times per day, but with fewer puffs at each use time. Users acknowledged that more research is needed to understand the safety and long-term effects of use. They mentioned dry mouth as a common side effect and common problems with reliability of e-cigs. Understanding these views may help health professionals to assess and assist e-cig users, and in the future, may help regulators to improve quality and reduce risks.

Background The capability of electronic cigarette devices (e-cigs) to deliver nicotine is key to their potential to replace combustible cigarettes. We compared nicotine delivery and subjective effects associated with the use of two classes of e-cigarettes and cigarettes. Methods 14 e-cigarette users were instructed to vape their own e-cigarette device every 20 seconds for 10 minutes while blood was drawn at 1, 2, 4, 6, 8, 10,12, and 15 minutes after initiating vaping. Users rated withdrawal symptoms and side effects before and after vaping. E-cigarette devices were classified as first-generation (same size as cigarette, no activation button) or advanced (larger than cigarette with an activation button). Separately, 10 cigarette smokers completed a similar protocol. Fisher’s Exact Test and two-sided t-tests were used as appropriate to determine differences in outcomes between first-generation e-cigarette users, advanced e-cigarette users, and smokers. Results Compared to first-generation devices, advanced devices were associated with greater serum nicotine C max (ng/ml) (11.5 v. 2.8, p = 0.0231) and greater nicotine boost (ng/ml) (10.8 v. 1.8, p = 0.0177). Overall, e-cigarettes users experienced a significant reduction in withdrawal and craving, although there were no significant differences between users of first-generation and advanced devices. Comparing e-cigarettes overall to cigarettes, cigarettes were associated with greater C max (25.9 v. 9.0, p = 0.0043) and greater nicotine boost (21.0 v. 8.2, p = 0.0128). Conclusions Advanced e-cigarettes delivered significantly more nicotine than first-generation devices but less than combustible cigarettes. Overall, e-cigarette use was associated with a reduction in withdrawal and craving with no reported side effects. The wide variation in nicotine absorption from different e-cigarette devices should be considered in studies of e-cigarettes for smoking cessation.

Current studies on the use of flavored e-liquid have used unclear methods to collect and report information on the use of flavors. This study adds a proposed method for classifying the flavors in the e-liquids used most commonly by experienced e-cig users. With a clear and explicit method for classifying self-reported flavors, future study results may be more easily compared.

Background: There is limited evidence about the effects of dual electronic cigarette (e-cig) and combustible cigarette use on lung health or other health outcomes. Studies that have evaluated these outcomes have not included estimates of e-cig or cigarette exposure in the analyses.Materials and Methods: Data analyzed were from 263 smokers participating in a randomized controlled trial designed to encourage participants to reduce their combustible cigarette use by substituting with an e-cig or a non-electronic cigarette substitute (cig-sub). T-tests were used to evaluate changes from baseline at 1 month and 3 months in lung function, blood pressure, pulse, exhaled carbon monoxide, and weight. Linear mixed effects models were used to test associations between health outcomes and study product group, including exposure to the study products (e-cig and cig-sub times used and days used in the past 7 days) and cigarettes per day (CPD).Results: There were few significant differences between the groups for lung function indices at any time point in the unadjusted analyses. There were significant reductions in diastolic blood pressure and pulse at 1 month in the unadjusted analyses for those in the e-cig group compared to the cig-sub group. CPD decreased significantly more for the e-cig group than for the cig-sub group at both time points. There were no significant associations between any measured health outcomes and group in the linear mixed effects models.

Background A brief “Lung Age” feedback intervention has shown promise for personalizing the health impact of smoking and promoting cessation in unselected smokers. Now that many healthcare organizations provide face-to-face cessation services, it is reasonable to ask whether such motivational feedback of lung function tests might improve treatment compliance and cessation rates in smokers wanting to quit. This study assessed effects of baseline motivational spirometry-based “Lung Age” feedback on treatment compliance and tobacco abstinence at 28-day follow-up. Methods This randomized controlled pilot study took place in Penn State University-affiliated outpatient medical practices. Participants were 225 adult smokers (≥ 5 cigarettes/day) willing to attend tobacco dependence treatment. At assessment lung function (FEV-1) and exhaled carbon-monoxide (CO) were assessed. The Intervention group (n=120) were randomly allocated to receive motivational “Lung Age” feedback estimated by FEV-1 and on exhaled CO; Control group (n=105) received minimal feedback. Participants were offered 6 weekly group smoking cessation sessions and nicotine patches and followed-up 28 days after target quit date. The primary outcome measure was self-reported 7-day tobacco abstinence, confirmed by CO<10ppm at 28-day follow-up. Results Quit rates were similar at follow-up (Intervention 50.8%; Control 52.4%; p=0.65) after controlling for abstinence predictors. Group attendance and patch use were similar. Among those attending follow-up (n=164, 73%), a greater proportion of the Intervention group had improved lung function (67% v. 46%; p=0.0083). Conclusions Baseline Lung Age feedback did not improve quit rates or compliance at 28-day follow-up in smokers seeking intensive treatment. This study was registered at ClinicalTrials.gov (identifier: NCT01980485).

This case series characterizes nicotine absorption among adults who regularly use a pod-based electronic nicotine delivery system.