Is there any legal and scientific basis for classifying electronic cigarettes as medications?

Associations between e-cigarette use and sleep health among adults in the United States, NHANES 2015-2018

OBJECTIVE

To examine the associations between e-cigarette use or dual (e-cigarette and combustible cigarette) use and short sleep duration and trouble sleeping among U.S. adults.

METHODS

We used 2015-2018 data from the National Health and Nutrition Examination Survey (NHANES) (n = 11,659). E-cigarette use and dual use were categorized as current, former, and never use. Short sleep duration was defined as sleep duration ≤6 h. Trouble sleeping was self-reported. Weighted logistic regression analyses were performed.

RESULTS

Among those with current e-cigarette use, 53.9 % were with current dual use and 23.8 % were with former dual use. Compared to never e-cigarette use, current e-cigarette use was associated with significantly higher odds of trouble sleeping (OR = 2.16, 95 % CI: 1.49-3.13), adjusting for potential confounders. Significant associations were also observed for former e-cigarette use versus never use with trouble sleeping (OR = 1.54, 95 % CI: 1.15-2.07) after full adjustment. Current cigarette use was associated with both short sleep duration (OR = 1.65, 95 % CI: 1.28-2.14) and trouble sleeping (OR = 1.36, 95 % CI: 1.03-1.79) after full adjustment. Additionally, the fully adjusted ORs for short sleep duration and trouble sleeping were 1.64 (95 % CI: 1.06-2.54) and 2.14 (95 % CI: 1.34-3.42) among those with current dual use, and 1.46 (95 % CI: 1.17-1.81) and 2.11 (95 % CI: 1.66-2.67) among those with former dual use, compared to those without dual use.

CONCLUSIONS

Current cigarette use or dual use is associated with significantly higher odds of short sleep duration and trouble sleeping. Moreover, former e-cigarette use or dual use is associated with increased odds of trouble sleeping.

E-cigarettes and Smoking Cessation in the United States According to Frequency of E-cigarette Use and Quitting Duration: Analysis of the 2016 and 2017 National Health Interview Surveys

INTRODUCTION

The purpose of this study was to examine the association between electronic cigarette (e-cigarette) use and smoking cessation among US adults. Duration of smoking cessation was taken into consideration because e-cigarette awareness and use were low in the United States before 2010.

METHODS

A pooled analysis of the 2016 and 2017 National Health Interview Surveys on current (N = 9935) and former smokers (N = 14 754) was performed. Adjusted prevalence ratios (aPRs), for sociodemographic factors, were calculated.

FINDINGS

Current e-cigarette use was reported by 10.5% (95% CI = 9.8% to 11.3%) of current smokers and 4.5% (95% CI = 4.0% to 5.0%) of former smokers. Prevalence was high in former smokers of less than 1 year (16.8%, 95% CI = 13.9% to 20.2%), 1-3 years (15.0%, 95% CI = 13.0% to 17.3%), and 4-6 years (10.5%, 95% CI = 8.6% to 12.7%), and very low in former smokers of more than 6 years (0.7%, 95% CI = 0.5% to 0.9%). Similar patterns were observed for daily e-cigarette use. Current e-cigarette use was negatively associated with being a former smoker when quit duration was ignored (aPR = 0.64, 95% CI = 0.59 to 0.69) but was positively associated with being a former smoker of less than 1 year (aPR = 1.44, 95% CI = 1.12 to 1.84) and 1-3 years (aPR = 1.21, 95% CI = 1.03 to 1.42). Daily e-cigarette use was not associated with being a former smoker when quit duration was ignored but was positively associated with being a former smoker of less than 1 year (aPR = 3.44, 95% CI = 2.63 to 4.49), 1-3 years (aPR = 2.51, 95% CI = 2.13 to 2.95), and 4-6 years (aPR = 1.84, 95% CI = 1.49 to 2.26).

CONCLUSIONS

Daily e-cigarette use is strongly associated with recent smoking cessation (≤6 years) among US adults. Frequency of e-cigarette use and smoking cessation duration are important parameters when analyzing the effects of e-cigarettes in population surveys.

IMPLICATIONS

There is controversy on whether e-cigarettes promote or prevent smoking cessation. This study presents a detailed analysis of the association between e-cigarette use and smoking cessation in the United States considering frequency of e-cigarette use and duration of smoking cessation. The latter was considered appropriate because e-cigarette awareness and use were low in the United States before 2010. Daily e-cigarette use is strongly associated with recent (≤6 years) smoking cessation in the United States. Both frequency of e-cigarette use and duration of smoking cessation are important factors in determining the effects of e-cigarettes in population studies.

E-cigarette use is strongly associated with recent smoking cessation: an analysis of a representative population sample in Greece

The purpose was to examine the association between e-cigarette use and smoking cessation according to quit duration in Greece in 2017. A cross-sectional survey of a representative sample of adults living in Attica prefecture was performed in May 2017 through telephone interviews. The present analysis was confined to current and former smokers (n = 2568). Logistic regression analyses were performed with current and current daily e-cigarette use being the dependent variables and demographics and smoking status (current smokers vs smoking cessation for ≤ 12 months, 13-36 months, 36-72 months, and > 72 months) being independent variables. Almost half of former smokers (47.7%) had quit smoking for ≤ 72 months. Current e-cigarette use was more prevalent among former smokers of ≤ 12 months (26.2%) and 13-36 months (27.0%), and was rare among former smokers of > 72 months (1.0%). Current e-cigarette use was strongly associated with smoking cessation for ≤ 12 months (OR 6.12, 95% CI 4.11-9.10, P < 0.001) and 13-36 months (OR 6.28, 95% CI 4.25-9.28, P < 0.001). Current daily e-cigarette use was also strongly associated with smoking cessation for ≤ 12 months (OR 10.41, 95% CI 6.56-16.53, P < 0.001) and 13-36 months (OR 11.18, 95% CI 7.12-17.55, P < 0.001). Current and current daily e-cigarette use were not significantly associated with smoking cessation for 37-72 months, and were negatively associated with smoking cessation for > 72 months. Current and current daily e-cigarette use are strongly associated with recent smoking cessation in Greece, suggesting a positive public health impact in a country with the highest prevalence of smoking in the European Union. E-cigarettes do not appear to promote relapse in long term former smokers. Duration of smoking cessation and frequency of e-cigarette use should be taken into consideration when examining the association between e-cigarette use and smoking cessation in population studies.

E-Cigarette Battery Explosions: Review of the Acute Management of the Burns and the Impact on Our Population

Electronic cigarettes, also known as e-cigarettes (E-cig), are lithium-battery-powered devices, which became available for sale in the United States in 2017. It has gained significant popularity among younger-generation tobacco smokers due to its advertisement as a non-toxic inhalation property and a potential smoking-cessation aid. The US Food and Drug Administration (FDA) has been regulating e-cigarettes as tobacco products and not as drug-delivery devices, as many medical experts think it should be categorized. In the last few years, the medical community has encountered increasing episodes of burn injuries secondary to e-cigarette battery explosion. Explosions occur through a process known as a "thermal runaway.” This process occurs when the battery overheats and the internal battery temperature increases dangerously high, to the point of inner fire and explosion. Overcharge, puncture, external heat, short circuit, amongst others, are conditions that cause a “thermal runaway.”

This is a retrospective review and analysis of six patients with superficial, partial, and full-thickness burn injuries related to e-cigarette battery explosions managed at Johns Hopkins Bayview Burn Center over the course of one year. Lund-Browder diagrams and calculations were used to assess the total body surface area (TBSA) burns. Laser Doppler imaging (LDI) was used to evaluate the indeterminate depth of the burn.

Only one of our six patients required tangential excision and skin grafting. The rest of our patients were treated conservatively with complex wound care, which included the mixed combination of topical collagenase and bacitracin, collagenase and mafenide, or silver sulfadiazine as a single-agent treatment with an excellent response. Five patients were discharged home within a week, including the patient who required operative excision and auto-grafting. One patient stayed for eight days for pain control and complex wound care.

Our experience with these burns has been similar to what is previously reported. Most of these burns are managed with complex wound care without any surgical interventions. The e-cigarette batteries seem more prone to failure due to an inherent weakness in their structural design. This makes them particularly susceptible to the “thermal runaway.” Therefore, we recognized the need to expand the regulation and control of the quality of these devices. Prevention of these burns will require continuing education for the community on the use of E-cig. products and its potential hazardous implications.

New efforts should be made to educate the community and healthcare providers regarding the potential hazardous implication of carrying these batteries. Also, there is insufficient data to support or deny the long-term health effects of using e-cigarettes.

Estimates of global research productivity in using nicotine replacement therapy for tobacco cessation: a bibliometric study

BACKGROUND

Tobacco use is a major healthcare problem worldwide. Tobacco smoking remains the most important risk factor for both cancer and heart diseases. This study was initiated due to the lack of published data concerning the real progress in research output in the use of nicotine replacement therapy (NRT) for tobacco cessation. This study was aimed to use bibliometric analysis to estimate the NRT literature indexed in Scopus database at global level.

METHODS

Core of the search strategy was the documents that contained specific words or phrases regarding NRT as keywords in the title. Publication output of most prolific countries was adjusted to the gross domestic product and population size. All citations analysis were accomplished on December 22, 2017.

RESULTS

A total of 2138 references were retrieved and published from 56 countries, which were published between 1970 and 2016. The USA has the most number of published articles accounted to 986, followed by the UK (312 publications) and then Australia (102 publications), and Sweden (102 publications). No data related to NRT were published from 156 countries. No significant correlation was found between the country population size or 2016 gross domestic product values and the number of publications of the top-10 most prolific countries in the field of NRT (r = - 0.156, P = 0.664; and r = - 0.173, P = 0.632, respectively). Furthermore, there is no correlation between prevalence of tobacco smoking and number of publications of the top-10 most prolific countries in the field of NRT (r = - 0.235, P = 0.514).

CONCLUSIONS

The present data reveal a solid mass of research activity on NRT. The USA was by far the predominant country in the amount of NRT-based research activity. NRT-based research activities were low or not available in most countries. The results of this study delineate a framework for better understanding the situations of current NRT research and prospective directions of the research in this field which could be applied for managing and prioritizing future research efforts in NRT research.

Electronic cigarettes: an aid in smoking cessation, or a new health hazard?

The issue of electronic cigarettes is one of the most controversial topics in public health. There is intense debate and dividing opinions about their use patterns, health effects and association with smoking. This is expected since they were only recently introduced to the market and they refer to a harm-reduction approach and strategy that is not universally accepted for smoking and tobacco use in the public health community. Three main factors determine the public health impact of electronic cigarettes: (1) their safety/risk profile, both relative to smoking and in absolute terms; (2) their effectiveness for smoking reduction and cessation; (3) the patterns of use by different population subgroups, especially never-smokers, and adoption of use by youth. This analysis presents a brief overview of currently available evidence and gaps in research covering these three factors.

Electronic cigarette use in the European Union: analysis of a representative sample of 27 460 Europeans from 28 countries

AIMS

To assess prevalence of electronic cigarette (e-cigarette) use, reported changes in smoking status due to e-cigarette use and correlates of e-cigarette use in the European Union (EU) member states in 2014.

DESIGN

Cross-sectional survey of EU citizens representative of the population (Special Eurobarometer 429).

SETTING

All 28 Member States of the EU.

PARTICIPANTS

A total of 27 460 EU citizens aged ≥ 15 years (after excluding those who responded 'Do not know' to the questions about smoking status and e-cigarette use).

MEASUREMENTS

Descriptive analysis [%, 95% confidence interval (CI)] of e-cigarette use prevalence (current use, past use and past experimentation) according to smoking status, self-reported changes in smoking status according to patterns of e-cigarette use and logistic regression analysis to examine correlates of e-cigarette use, especially socio-demographic factors and smoking status.

FINDINGS

Ever e-cigarette use was reported by 31.1% (95% CI = 30.0-32.2%) of current smokers, 10.8% (95% CI = 10.0-11.7%) of former smokers and 2.3% (95% CI = 2.1-2.6%) of never smokers. Past experimentation [7.2% (95% CI = 6.9-7.5%)] was more common than current [1.8% (95% CI = 1.6-1.9%)] and past use [2.6% (95% CI = 2.4-2.8%)]. Extrapolated to the whole population, approximately 48.5 million EU citizens were ever e-cigarette users, with 76.8% using nicotine-containing e-cigarettes. An estimated 6.1 and 9.2 million EU citizens had quit and reduced smoking with the help of e-cigarettes, respectively. Initiation with e-cigarettes was reported by 0.8% (95% CI = 0.6-0.9%) of participants who reported ever use of any tobacco-related product. Only 1.3% (95% CI = 1.1-1.5%) of never smokers used nicotine-containing e-cigarettes, with 0.09% (95% CI = 0.04-0.14%) reporting daily nicotine use. Smoking cessation with the help of e-cigarettes was reported by 35.1% (95% CI = 30.7-39.5%) of current e-cigarette users, while a further 32.2% (95% CI = 29.9-36.5%) reported smoking reduction. Being current [odds ratio (OR) = 21.23, 95% CI = 18.32-24.59) or former smokers (OR = 6.49, 95% CI = 5.49-7.67) were the strongest correlates of ever e-cigarette use.

CONCLUSIONS

E-cigarette use in the European Union appears to be largely confined to current or former smokers, while current use and nicotine use by people who have never smoked is rare. More than one-third of current e-cigarette users polled reported smoking cessation and reduction.

Knowledge and Perceptions about Nicotine, Nicotine Replacement Therapies and Electronic Cigarettes among Healthcare Professionals in Greece

Introduction. The purpose of this study was to evaluate the knowledge and perceptions of Greek healthcare professionals about nicotine, nicotine replacement therapies and electronic cigarettes. Methods. An online survey was performed, in which physicians and nurses working in private and public healthcare sectors in Athens-Greece were asked to participate through email invitations. A knowledge score was calculated by scoring the correct answers to specific questions with 1 point. Results. A total of 262 healthcare professionals were included to the analysis. Most had daily contact with smokers in their working environment. About half of them considered that nicotine has an extremely or very important contribution to smoking-related disease. More than 30% considered nicotine replacement therapies equally or more addictive than smoking, 76.7% overestimated their smoking cessation efficacy and only 21.0% would recommend them as long-term smoking substitutes. For electronic cigarettes, 45.0% considered them equally or more addictive than smoking and 24.4% equally or more harmful than tobacco cigarettes. Additionally, 35.5% thought they involve combustion while the majority responded that nicotine in electronic cigarettes is synthetically produced. Only 14.5% knew about the pending European regulation, but 33.2% have recommended them to smokers in the past. Still, more than 40% would not recommend electronic cigarettes to smokers unwilling or unable to quit smoking with currently approved medications. Cardiologists and respiratory physicians, who are responsible for smoking cessation therapy in Greece, were even more reluctant to recommend electronic cigarettes to this subpopulation of smokers compared to all other participants. The knowledge score of the whole study sample was 7.7 (SD: 2.4) out of a maximum score of 16. Higher score was associated with specific physician specialties. Conclusions. Greek healthcare professionals appear to overestimate the adverse effects of nicotine, and many would not recommend any nicotine-containing product as a long-term smoking substitute. Additionally, they have poor knowledge about the function and characteristics of electronic cigarettes.

Genetic Factors for Enhancement of Nicotine Levels in Cultivated Tobacco

Nicotine has practical applications relating to smoking cessation devices and alternative nicotine products. Genetic manipulation for increasing nicotine content in cultivated tobacco (Nicotiana tabacum L.) may be of value for industrial purposes, including the possibility of enhancing the efficiency of nicotine extraction. Biotechnological approaches have been evaluated in connection with this objective, but field-based results are few. Here, we report characterization of two genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs), NtMYC2a and NtMYC2b from tobacco. Overexpression of NtMYC2a increased leaf nicotine levels in T1 transgenic lines approximately 2.3-fold in greenhouse-grown plants of tobacco cultivar 'NC 95'. Subsequent field testing of T2 and T3 generations of transgenic NtMYC2a overexpression lines showed nicotine concentrations were 76% and 58% higher than control lines, respectively. These results demonstrated that the increased nicotine trait was stably inherited to the T2 and T3 generations, indicating the important role that NtMYC2a plays in regulating nicotine accumulation in N. tabacum and the great potential of NtMYC2a overexpression in tobacco plants for industrial nicotine production. Collected data in this study also indicated a negative feedback inhibition of nicotine biosynthesis. Further enhancement of nicotine accumulation in tobacco leaf may require modification of the processes of nicotine transport and deposition.

Regulation in the face of uncertainty: the evidence on electronic nicotine delivery systems (e-cigarettes)

Tobacco smoking is the largest single preventable cause of many chronic diseases and death. Effective treatments exist; however, few smokers use them and most try to quit by themselves. Most of the tobacco cigarette’s toxicity is related to the combustion process. Models of harm reduction applied to tobacco suggest that switching from inhalation of combustible products to a noncombustible nicotine delivery product would likely result in a vast reduction in tobacco-related death and illness. Currently available evidence raises no doubt that electronic cigarettes (e-cigs) are by far less harmful than smoking (although probably not absolutely safe) and have the potential to be the most effective tobacco harm reduction products due to their unique property of resembling smoking and providing satisfaction to the user. A lot of controversy is surrounding e-cigs and their regulation, much of which is based on the precautionary principle. Although monitoring and further research is definitely needed, the arguments used to implement severe restrictions or bans are mostly hypothetical, weakly supported by evidence, and, in some cases, derived from mispresentation or misinterpretation of the study findings. Regulators should keep in mind that the target population is smokers who want to reduce or quit their deadly tobacco consumption. To achieve this goal, smokers should be honestly informed on the relative harmfulness of the different products. E-cigs are not tobacco products and are not used as medications. For this reason, a specific regulatory scheme is needed, separate from tobacco or medicinal products regulation. Regulation should implement specific quality criteria for products, rules for the exclusion of chemicals of reasonable concern, and appropriate testing for possible contaminants. Additionally, manufacturing standards derived from the food industry should be implemented and adjusted for specific conditions related to e-cigs. Finding the appropriate balance between safety and acceptability of use by smokers will be important in achieving the maximum public health benefit. Labeling should be specified, with warnings about exposure to skin or through ingestion and discouragement of use by nonsmokers, related to the presence of nicotine. Finally, advertising and marketing should not be banned, but appropriately regulated in order to encourage use by the intended population while avoiding use by never-smokers. E-cigs should be appealing to smokers (but not to nonsmokers), while availability and pricing should be strong competitive advantages of e-cigs relative to tobacco cigarettes.

Nicotine levels and presence of selected tobacco-derived toxins in tobacco flavoured electronic cigarette refill liquids

BACKGROUND

Some electronic cigarette (EC) liquids of tobacco flavour contain extracts of cured tobacco leaves produced by a process of solvent extraction and steeping. These are commonly called Natural Extract of Tobacco (NET) liquids. The purpose of the study was to evaluate nicotine levels and the presence of tobacco-derived toxins in tobacco-flavoured conventional and NET liquids.

METHODS

Twenty-one samples (10 conventional and 11 NET liquids) were obtained from the US and Greek market. Nicotine levels were measured and compared with labelled values. The levels of tobacco-derived chemicals were compared with literature data on tobacco products.

RESULTS

Twelve samples had nicotine levels within 10% of the labelled value. Inconsistency ranged from -21% to 22.1%, with no difference observed between conventional and NET liquids. Tobacco-specific nitrosamines (TSNAs) were present in all samples at ng/mL levels. Nitrates were present almost exclusively in NET liquids. Acetaldehyde was present predominantly in conventional liquids while formaldehyde was detected in almost all EC liquids at trace levels. Phenols were present in trace amounts, mostly in NET liquids. Total TSNAs and nitrate, which are derived from the tobacco plant, were present at levels 200-300 times lower in 1 mL of NET liquids compared to 1 gram of tobacco products.

CONCLUSIONS

NET liquids contained higher levels of phenols and nitrates, but lower levels of acetaldehyde compared to conventional EC liquids. The lower levels of tobacco-derived toxins found in NET liquids compared to tobacco products indicate that the extraction process used to make these products did not transfer a significant amount of toxins to the NET. Overall, all EC liquids contained far lower (by 2-3 orders of magnitude) levels of the tobacco-derived toxins compared to tobacco products.

Nicorette reborn? E-cigarettes in light of the history of nicotine replacement technology

BACKGROUND

E-cigarettes are currently hotly debated as threatening to re-normalize cigarette smoking and make nicotine addiction publicly acceptable once more. In this paper I contextualize the e-cigarette controversy in light of longstanding disagreements about the meaning and significance of nicotine replacement technologies. A concerted effort to develop such technologies first emerged in Sweden at the end of the 1960s, embodying a vital tension. Two competing 'scripts' vied to influence and shape innovative designs. On the one hand, Nicorette chewing gum was conceived as a therapeutic device aiding smoking cessation. On the other hand, it was cast as a cigarette substitute designed to deliver nicotine 'in the right way', thereby advancing the creative destruction of the combustible cigarette as a drug delivery platform.

METHOD

Drawing on historical and archival research I outline how these two alternative innovation scripts started out entangled with each other before becoming disentangled, leading to the eventual stabilization of Nicorette gum as a therapeutic product to be deployed in the treatment of smoking as a dependence disorder.

RESULTS AND CONCLUSION

While a post-therapeutic future for nicotine replacement was charted by Michael Russell at the beginning of the 1990s, it is only with the rise of e-cigarettes after 2003 that such a future has started to verge on reality. E-cigarettes can be seen as resurrecting the historically marginalized script of nicotine replacement as dedicated to righting nicotine consumption and freeing it from the wrongful drug delivery of the modern cigarette.

Are E-cigarettes a safe and good alternative to cigarette smoking?

Electronic cigarettes (E-cigarettes) are devices that can vaporize a nicotine solution combined with liquid flavors instead of burning tobacco leaves. Since their emergence in 2004, E-cigarettes have become widely available, and their use has increased exponentially worldwide. E-cigarettes are aggressively advertised as a smoking cessation aid; as healthier, cheaper, and more socially acceptable than conventional cigarettes. In recent years, these claims have been evaluated in numerous studies. This review explores the development of the current E-cigarette and its market, prevalence of awareness, and use. The review also explores the beneficial and adverse effects of E-cigarettes in various aspects in accordance with recent research. The discussed aspects include smoking cessation or reduction and the health risks, social impact, and environmental consequences of E-cigarettes.

Prevalence and reasons for use of electronic cigarettes among smokers: Findings from the International Tobacco Control (ITC) Netherlands Survey

BACKGROUND

Not much is known about how people in the Netherlands respond to electronic cigarettes (e-cigarettes); how many know about them, which people try them, keep using them and why, and what are changes over time regarding awareness and use?

METHODS

We used samples of smokers aged 15 years and older from 2008 (n=1820), 2010 (n=1702), 2013 (n=1530), and 2014 (n=1550) as part of the International Tobacco Control (ITC) Netherlands Survey. Reasons for use and characteristics of smokers were examined using the sample from 2014. Logistic regression analyses were conducted to evaluate the associations between smoking-related variables with ever trying e-cigarettes and current e-cigarette use.

RESULTS

In 2014, 91.4% of Dutch smokers reported being aware of e-cigarettes (97.1% in 2008, 89.2% in 2010, and 85.5% in 2013), 40.0% reported having ever tried them (13.4% in 2008, 14.5% in 2010, and 19.6% in 2013), and 15.9% were currently using them (4.0% in 2008, 1% in 2010, and 3.9% in 2013). The main reason given for using e-cigarettes was to reduce the number of regular cigarettes smoked per day (79%). Ever trying e-cigarettes among those aware of e-cigarettes was associated with being young, smoking more regular cigarettes per day, having made a quit attempt in the last year, having used smoking cessation pharmacotherapy in the last year, and reporting high awareness of the price of regular cigarettes. Smokers who kept using e-cigarettes had a higher educational background, had higher harm awareness for the health of others, and were less likely to have a total smoking ban at home.

CONCLUSION

E-cigarettes are increasingly used by Dutch smokers. Commonly endorsed motivations for current e-cigarette use were to reduce tobacco smoking and because e-cigarettes are considered to be less harmful than tobacco cigarettes.

Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins

INTRODUCTION

The purpose of this study was to evaluate sweet-flavored electronic cigarette (EC) liquids for the presence of diacetyl (DA) and acetyl propionyl (AP), which are chemicals approved for food use but are associated with respiratory disease when inhaled.

METHODS

In total, 159 samples were purchased from 36 manufacturers and retailers in 7 countries. Additionally, 3 liquids were prepared by dissolving a concentrated flavor sample of known DA and AP levels at 5%, 10%, and 20% concentration in a mixture of propylene glycol and glycerol. Aerosol produced by an EC was analyzed to determine the concentration of DA and AP.

RESULTS

DA and AP were found in 74.2% of the samples, with more samples containing DA. Similar concentrations were found in liquid and aerosol for both chemicals. The median daily exposure levels were 56 μg/day (IQR: 26-278 μg/day) for DA and 91 μg/day (IQR: 20-432 μg/day) for AP. They were slightly lower than the strict NIOSH-defined safety limits for occupational exposure and 100 and 10 times lower compared with smoking respectively; however, 47.3% of DA and 41.5% of AP-containing samples exposed consumers to levels higher than the safety limits.

CONCLUSIONS

DA and AP were found in a large proportion of sweet-flavored EC liquids, with many of them exposing users to higher than safety levels. Their presence in EC liquids represents an avoidable risk. Proper measures should be taken by EC liquid manufacturers and flavoring suppliers to eliminate these hazards from the products without necessarily limiting the availability of sweet flavors.

Worldwide research productivity in the field of electronic cigarette: a bibliometric analysis

BACKGROUND

Electronic cigarette (EC) is an emerging phenomenon that is becoming increasingly popular with smokers worldwide. There is a lack of data concerning the evaluation of research productivity in the field of EC originating from the world. The main objectives of this study were to analyse worldwide research output in EC field, and to examine the authorship pattern and the citations retrieved from the Scopus database.

METHODS

Data were searched for documents with specific words regarding EC as "keywords" in the title. Scientific output was evaluated based on the methodology developed and used in other bibliometric studies by investigation: (a) total and trends of contributions in EC research during all previous years up to the date of data analysis (June 13, 2014); (b) authorship patterns and research productivity; (c) countries contribution; and (d) citations received by the publications.

RESULTS

Three hundred and fifty-six documents were retrieved comprising 31.5% original journal articles, 16% letters to the editor, 7.9% review articles, and 44.6% documents that were classified as other types of publications, such as notes or editorials or opinions. The retrieved documents were published in 162 peer-reviewed journals. All retrieved documents were published from 27 countries. the largest number of publications in the field of EC was from the United States of America (USA); (33.7%), followed by the United Kingdom (UK); (11.5%), and Italy (8.1%). The total number of citations at the time of data analysis was 2.277, with an average of 6.4 citations per document and median (interquartile range) of 0.0 (0.0-5.0). The h-index of the retrieved documents was 27. The most productive institutions were Food and Drug Administration, USA (4.2% of total publications) followed by Universita degli Studi di Catania, Italy (3.9%), University of California, San Francisco, USA (3.7%).

CONCLUSIONS

This bibliometric study is a testament to the progress in EC research from the world over the last few years. More effort is needed to bridge the gap in EC-based research and to promote better evaluation of EC, risks, health effects, or control services worldwide.

Characteristics, perceived side effects and benefits of electronic cigarette use: a worldwide survey of more than 19,000 consumers

Background: Electronic cigarette (EC) use has grown exponentially over the past few years. The purpose of this survey was to assess the characteristics and experiences of a large sample of EC users and examine the differences between those who partially and completely substituted smoking with EC use. Methods: A questionnaire was prepared, translated into 10 different languages and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. Results: In total, 19,414 participants were included in the analysis, with 88 of them (0.5%) reported not being smokers at the time of EC use initiation. Complete substitution of smoking was reported by 81.0% of participants (former smokers) while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. They were using ECs for a median of 10 months. They initiated EC use with a median of 18 mg/mL nicotine-concentration liquids; 21.5% used higher than 20 mg/mL. Only 3.5% of participants were using 0-nicotine liquids at the time of the survey. Former smokers were highly dependent (Fagerström Test for Cigarette Dependence = 7) and were heavier smokers (21 cigarettes per day when smoking) compared to current smokers. The most important reasons for initiating EC use for both subgroups was to reduce the harm associated with smoking and to reduce exposure of family members to second-hand smoking. Most considered ECs as less harmful than tobacco cigarettes, while 11.0% considered them absolutely harmless. Side effects were reported by more than half of the participants (59.8%), with the most common being sore/dry mouth and throat; side effects were mild and in most cases were subsequently resolved (partially or completely). Participants experienced significant benefits in physical status and improvements in pre-existing disease conditions (including respiratory disease such as asthma and chronic obstructive lung disease). Being former smoker was independently associated with positive effects in health and improvements in disease conditions. Conclusions: The results of this worldwide survey of dedicated users indicate that ECs are mostly used to avoid the harm associated with smoking. They can be effective even in highly-dependent smokers and are used as long-term substitutes for smoking. High levels of nicotine are used at initiation; subsequently, users try to reduce nicotine consumption, with only a small minority using non-nicotine liquids. Side effects are minor and health benefits are substantial, especially for those who completely substitute smoking with EC use. Further population and interventional studies are warranted.