1. bookTom 30 (2021): Zeszyt 3 (July 2021)
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2719-9509
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A Cross-Sectional Study of Electronic Cigarette Use Among Chinese Adult Populations in Four Cities of China. Part I. Questionnaire Survey

Data publikacji: 01 Oct 2021
Tom & Zeszyt: Tom 30 (2021) - Zeszyt 3 (July 2021)
Zakres stron: 138 - 148
Otrzymano: 08 May 2020
Przyjęty: 30 Aug 2021
Informacje o czasopiśmie
License
Format
Czasopismo
eISSN
2719-9509
Pierwsze wydanie
01 Jan 1992
Częstotliwość wydawania
4 razy w roku
Języki
Angielski
INTRODUCTION

An electronic cigarette (EC), also known as an electronic nicotine delivery system (ENDS), is a device that uses a battery power source to atomize specialized liquid in order to transfer nicotine, and other substances, to the respiratory system by means of electronic heating. A Chinese pharmacist invented the first e-cigarette product in 2003. One year later, ECs emerged in the Chinese market and then rapidly expanded worldwide (1). Large-scale use in China was observable since 2015. At present, ECs in the Chinese market are predominately sold through internet and retail stores in high-income and middle-income cities.

Under the global anti-smoking legislation, the usage of ECs has increased exponentially (2). Research on the prevalence and cognitive status of users of ECs and the effects on users’ health have been performed in Europe, America, and Canada. The results suggest that the usage of ECs is strongly associated with the use of traditional cigarettes (3, 4). In addition, a United States study demonstrated that the availability of ECs could also expand the market of tobacco products. Over the years, the total number of young people using both kinds of tobacco products has increased, instead of simply replacing traditional cigarettes with ECs (5).

An investigation of EC users among smokers in Beijing found that 12.8% (122 participants) of traditional cigarette smokers had used ECs for some time in the past (6). Among the 122 smokers who used ECs, the majority (84%) thought that ECs were not addictive or less addictive than cigarettes, and more than 70% considered that ECs were healthier and less risky than cigarettes. Li et al. conducted a survey in urban residents in Tianjin and found that 2.3% (45 participants) used ECs. Overall, the percentage of EC users who tried to quit smoking in the past 12 months was significantly higher than those who had never used ECs (7). There is a lack of comprehensive studies to evaluate the EC-user behavior in Chinese populations. To better understand the current prevalence of EC use in Chinese populations, this study surveyed EC users by using a questionnaire addressing characteristics of the participants, consumption behavior, user history and status of tobacco products, user perception and the influence on the EC users’ personal and families’ health.

METHODS
Representative area and volunteer recruitment

Four cities were selected to launch the project, which were selected based on the Baidu search indices (24). Notably, these cities were the top four cities for EC usage in the period between October 2015 and October 2017. EC users were recruited both through online advertisements and EC experience stores.

Participant requirements in the study

In order to participate, volunteers must have an EC usage history for 3 months past with a frequency of at least 3 days per week. Moreover, participants were required to be over 18 years old, without serious cardiovascular or respiratory diseases, and they had to sign their informed consent prior to in-person interviews. The exclusion criteria included: a) illegal drugs abuse; b) major depressive disorders or other psychiatric disorders; c) severe cardiovascular diseases, chronic obstructive pulmonary disease, lung cancer or other diagnosed tumors, and severe physiological deformities. Women were excluded if they were breastfeeding or pregnant.

Questionnaire

On the basis of multiple considerations, like extensive consultation with epidemiologic researchers, market salesmen, product researchers, and development personnel, a large number of studies were consulted. Based on previous studies, we designed our survey questionnaire for EC-using participants, which included the following elements: (i) Characteristics including age, gender, education, occupation and other information; (ii) Consumption behavior including duration of EC use, device type (cigarette-like: disposable and one-off use; tank: replacement of EC liquid cartridges and reusable batteries; customizer: refillable with e-liquids to supplement EC vapor), nicotine concentration, taste, usage frequency, priority factors; (iii) History and status of tobacco products, former daily use of traditional cigarettes, span of time in which traditional cigarettes were consumed, uptake or reduction of smoking after EC use; (iv) Perception and reasons for use, method of understanding, harm perception, smoking cessation, influence on surrounding people; (v) ECs influence on the users’ personal and family health, irritation of the mouth, changes in the respiratory tract, changes in physical health, and attitude of family and friends towards ECs.

The study was reviewed by and received ethics clearance from the Public Health Institute of the University of Zhengzhou. The participants’ voluntary informed consent, confidentiality, and good research practice were followed throughout the investigation. The data of the questionnaire survey was collected through in-person interviews. In detail, the photos, videos of EC devices, and information from volunteers were all collected at the interview site.

Statistical analysis

All analyses were conducted using SPSS 22.0 Demo software (SSPS Inc., Chicago, IL, USA). Continuous variables were defined as: “EC use times per day”, “Amount of liquid per day”. Data are expressed as mean ± SD. Quantitative data were analyzed by single factor ANOVA with the Levene test to test homogeneity of variance. When variance was homogeneous, the Bonferroni method was used for multiple comparisons of the mean of each group. If variance was uneven, Dunnett's T3 test was used for multiple comparisons. Chi-square analysis was used to examine differences in categorical variables, such as flavor preferences, nicotine concentrations, duration of EC use, using frequency during the past 30 days, and the proportion of the dual users who smoked cigarettes containing different concentrations of “tar” before and after using ECs.

RESULTS
Target areas and populations

Through the geographical distribution of the Baidu search index and the city ranking of the Baidu search index, four cities including Beijing, Shanghai, Guangzhou, and Shenzhen, were marked as high EC usage cities. In this study, 18,970 people were invited through internet shops and local EC stores. Ultimately 527 people met the research conditions, and 511 people participated in the survey. Among those who did not participate were many who were reluctant to engage in all requested procedures prior to the start. The final group consisted of 82, 123, 149, and 157 volunteers from Beijing, Shanghai, Guangzhou, and Shenzhen, respectively. The invitation/success rate of e-cigarette users was only 2.8%. The main factor affecting the success rate was the low popularity of e-cigarettes in China at the time.

Sociodemographic characteristics

The baseline sociodemographic characteristics of the participants are displayed in Table 1. EC users were disproportionately young, with 47.6% between 18 and 29 years old. The majority of EC users was male, with an overall ratio of 90.6%. Variance ratios based on gender suggest that the city of Shanghai had the largest percentage of women users among the four cities, which was about 15.4%. As to the participants’ education level, it was found that the proportion of participants with a bachelor degree, an associate degree, or high school graduation was 45.2%, 36.0% and 16.8%, respectively. According to the occupational distribution, the number of participants working in the general staff of a company and the middle or senior management were relatively higher than others, which were 28.4% and 23.3% respectively. 36.9% of the participants were students in Shenzhen. Figure 1 shows in more detail the differences in occupational distribution across cities and the total.

Basic distribution of EC users, n (%).

Characteristics Classification Number of participants (%)

Total Beijing Shanghai Guangzhou Shenzhen
Age (years) 18–29 243 (47.6) 38 (46.3) 42 (34.1) 44 (29.5) 119 (75.8)
30–39 175 (34.2) 30 (36.6) 57 (46.3) 72 (48.3) 16 (10.2)
40–49 67 (13.1) 7 (8.5) 18 (14.6) 22 (14.8) 20 (12.7)
Above 50 26 (5.1) 7 (8.5) 6 (4.9) 11 (7.4) 2 (1.3)

Gender Male 463 (90.6) 76 (92.7) 104 (84.6) 131 (87.9) 152 (96.8)
Female 48 (9.4) 6 (7.3) 19 (15.4) 18 (12.1) 5 (3.2)

Education Doctoral 1 (0.2) 1 (1.2) 0 (0.0) 0 (0.0) 0 (0.0)
Master 6 (1.2) 5 (6.1) 1 (0.8) 0 (0.0) 0 (0.0)
Bachelor 231 (45.2) 55 (67.1) 76 (61.8) 68 (45.6) 32 (20.4)
Associate degree 184 (36.0) 13 (15.9) 36 (29.3) 57 (38.3) 78 (49.7)
High School 86 (16.8) 8 (9.8) 10 (8.1) 22 (14.8) 46 (29.3)
Others 3 (0.6) 0 (0.0) 0 (0.0) 2 (1.3) 1 (0.6)

Occupation General staff 145 (28.4) 24 (39.3) 43 (35.0) 43 (28.9) 35 (22.3)
Middle or senior level management 119 (23.3) 16 (19.5) 41 (33.3) 47 (31.5) 15 (9.6)
Students 70 (13.7) 7 (8.5) 3 (2.4) 2 (1.3) 58 (36.9)
Freelancers 51 (10.0) 13 (15.9) 10 (8.1) 12 (8.1) 16 (10.2)
Private business owners / Partners 44 (8.6) 7 (8.5) 11 (8.9) 16 (10.9) 10 (6.4)
General staff of Government Departments / Institutions 24 (4.7) 2 (2.4) 6 (4.9) 12 (8.1) 4 (2.5)
Blue-collar workers in a servicebranch (e.g., restaurants or shops) 12 (2.3) 3 (3.7) 1 (0.8) 2 (1.3) 6 (3.8)
Middle or senior level management in Government Departments / Institutions 11 (2.2) 2 (2.4) 3 (2.4) 1 (0.7) 5 (3.2)
Owners of small shops / restaurants, etc. 10 (2.0) 0 (0.0) 1 (0.8) 6 (4.1) 3 (1.9)
Labourers / blue-collar / manual workers 10 (2.0) 2 (2.4) 1 (0.8) 4 (2.7) 3 (1.9)
Middle / senior level professionals (e.g., lawyers, doctors, scientists, etc.) 9 (1.8) 3 (3.7) 2 (1.6) 3 (2.0) 1 (0.6)
Retired 3 (0.6) 1 (1.2) 1 (0.8) 1 (0.7) 0 (0.0)
Unemployed / laid off 3 (0.6) 2 (2.4) 0 (0.0) 0 (0.0) 1 (0.6)

Figure 1

Occupational distribution in cities and total (%).

Behavior

An investigation of the type of EC used in the four cities showed that the majority of users (n = 491, 96.1%) chose the cartomized device (shown in Table 2). Only 15 and 5 participants, respectively, chose the refillable tank device and disposable cigarette-like ECs. In the group of users of the customized device, age groups were used to analyze and compare consumer behaviors. Statistical analysis and distribution of group data determined that there was no difference in daily usage of ECs and EC liquid among all age groups (shown in Table 3).

Types of e-cigarettes used in the four cities.

Classification Number of participants (%)

Total Beijing Shanghai Guangzhou Shenzhen
Cartomized 491 (96.1) 80 (97.6) 113 (91.9) 147 (98.7) 151 (96.2)
Tank 15 (2.9) 2 (2.4) 9 (7.3) 2 (1.3) 2 (1.3)
Disposable 5 (1.0) 0 (0) 1 (0.8) 0 (0) 4 (2.5)

Daily usage of ECs and EC liquid by age groups.

User behaviour Age group (years) X̅ ± SD
Frequency per day (times/day) 18 – 29 88.3 ± 88.3
30 – 39 83.0 ± 88.1
40 – 49 64.0 ± 75.2
Over 50 62.0 ± 73.0
Volume of EC liquid per day (mL/day) 18 – 29 7.2 ± 7.3
30 – 39 6.0 ± 6.0
40 – 49 3.4 ± 4.4*
Over 50 2.5 ± 1.8*

There is a statistical difference in the age groups of 18 – 29 and 30 – 39 years.

Compared with the age groups of “18–29 years” and “30–39 years”, the amounts of liquid used per day in the age groups of “40–49 years” and “over 50 years” were lower (p < 0.01).

Flavor preferences were grouped into five categories: Fruit – fresh fruit such as bananas and apples (n = 294, 59.9%); tobacco (imitation CHUNGHWA, Furogwang, Yuxi, or similar) (n = 101, 20.6%); cigar flavor (n = 7, 1.4%); chocolate flavor (n = 5, 1.0%); menthol flavor (n = 62, 12.6%,); or other (flavors not readily classified by the above mentioned categories, such as fresh milk, Red Bull, ice cream, Coke, Yakult, or red wine) (n = 22, 4.5%). Most EC users surveyed were found to prefer fruit-flavored products. Flavor preference was observed to be further stratified by age group. The majority of participants in the age group of 18–29 years preferred fruit flavors (n = 173, 73.3%).

However, preference for fruit flavors decreased among the 30–39 year-old participants (n = 79, 48.2%). The concentration of nicotine was divided into 5 grades: nicotine-free; low: 1–5 mg/mL (0.1–0.5%); moderate: 6–11 mg/mL (0.6%–1.1%); high: 12–20 mg/mL (1.2%–2.0%); and > 20 mg/mL. A majority (n = 284, 57.8%) preferred low nicotine concentrations. Only one user reported a preference for an EC containing >20 mg/mL nicotine. EC use duration of the majority of users ranged from 6 months to 2 years (65.3%). Most participants (n = 313, 63.8%) used ECs every day, with no significant differences across all age groups in the usage frequency in the past 30 days. (Table 4).

The differences of the use patterns among age groups, n (%).

Total Age 18 – 29 years Age 30 – 39 years Age 40 – 49 years Age over 50 years F p
Flavor preference Fruit 294 (59.9) 173 (73.3) 79 (48.2) 34 (51.5) 8 (32.0) 70.487 < 0.001
Tobacco 101 (20.6) 23 (9.7) 42 (25.6) 28 (42.4) 8 (32.0)
Cigar 7 (1.4) 1 (0.4) 5 (3.0) 1 (1.5) 0 (0.0)
Chocolate 5 (1.0) 1 (0.4) 3 (1.8) 0 (0.0) 1 (4.0)
Menthol 62 (12.6) 26 (11.0) 27 (16.5) 2 (3.0) 7 (28.0)
Others 22 (4.5) 12 (5.1) 8 (4.9) 1 (1.5) 1 (4.0)

Nicotine concentration 0 mg/mL 85 (17.3) 34 (14.4) 29 (17.7) 14 (21.2) 8 (32.0) 51.874 < 0.001
Low 284 (57.8) 164 (69.5) 88 (53.7) 23 (34.8) 9 (36.0)
Moderate 77 (15.7) 20 (8.5) 36 (22.0) 17 (25.8) 4 (16.0)
High 13 (2.6) 5 (2.1) 2 (1.2) 5 (7.6) 1 (4.0)
≥20 mg/mL 1 (0.2) 0 (0.0) 0 (0.0) 1 (1.5) 0 (0.0)
Don’t know 31 (6.3) 13 (5.5) 9 (5.5) 6 (9.1) 3 (12.0)

Duration of use 3 – 6 months 75 (15.3) 42 (17.8) 17 (10.4) 14 (21.2) 2 (8.0) 34.793 0.003
6 – 12 months 149 (30.3) 81 (34.3) 39 (23.8) 21 (31.8) 8 (32.0)
1 – 2 years 172 (35.0) 73 (30.9) 78 (47.6) 14 (21.2) 7 (28.0)
2 – 3 years 57 (11.6) 30 (12.7) 16 (9.8) 8 (12.1) 3 (12.0)
3 – 5 years 23 (4.7) 6 (2.5) 8 (4.9) 6 (9.1) 3 (12.0)
> 5 years 15 (3.1) 4 (1.7) 6 (3.7) 3 (4.5) 2 (8.0)

Frequency of use in past 30 days 3 – 4 days/week 89 (18.1) 41 (17.4) 32 (19.5) 11 (16.7) 5 (20.0) 4.731 0.579
5 – 6 days/week 89 (18.1) 42 (17.8) 28 (17.1) 17 (25.8) 2 (8.0)
per day 313 (63.8) 153 (64.8) 104 (63.4) 38 (57.6) 18 (72.0)
Usage status of tobacco products

Table 5 displays the current use of the different tobacco products. In Table 6 the term “Product usage” was individually separated into (i) users who only used ECs (n = 137, 26.8%), including non smokers and former smokers, (ii) users who simultaneously smoked conventional cigarettes (n = 374, 73.2%) termed as “dual use”. In the group of ECs-only use, 80.3% of the participants were cigarette smokers. This means that smoking may affect the use of e-cigarettes (Table 6). In the group of dual users, there were a lot of participants (88.2%) who previously smoked before starting to use ECs. It should also be noted that 11.8% of the participants never smoked before using ECs.

Usage status of tobacco products, n (%).

Product usage Total Beijing Shanghai Guangzhou Shenzhen
EC only 137 (26.8) 21 (25.6) 31 (25.2) 42 (28.2) 43 (27.4)
Dual usage 374 (73.2) 61 (74.4) 92 (74.8) 107 (71.8) 114 (72.6)

The history of cigarette smoking for EC-only users and dual users, n (%).

User of: User history/status Total Beijing Shanghai Guangzhou Shenzhen
ECs only Always using ECs only 101 (19.7) 12 (14.3) 32 (25.8) 43 (28.6) 15 (9.3)
Smoker before using ECs only 410 (80.3) 70 (85.7) 91 (74.2) 106 (71.4) 142 (90.7)
Dual usage Smoker before using ECs 451 (88.2) 65 (78.7) 100 (81.5) 139 (93.5) 147 (93.9)
Nonsmoker before using ECs 60 (11.8) 17 (21.3) 23 (18.5) 10 (6.5) 10 (6.1)

And Table 6 furthermore shows that some participants will smoke cigarettes after using ECs.

On average, after using an EC, 20.7% of conventional cigarette smokers attempted to quit smoking. Geographically, this value varied somewhat in Beijing (25.0%), Shanghai (19.4%), Guangzhou (17.4%), and Shenzhen (22.5%). Successful smoking cessation within one month was at 27.9%. And the time interval necessary for quitting smoking in different cities proved quite different. In Beijing, 43.8% of EC-using participants quit smoking within a month whereas 45.2 % of EC consumers of Shenzhen quit smoking within 3 months (Table 7).

Smoking cessation among EC users (%).

Smoking cessation within Total (%) Beijing (%) Shanghai (%) Guangzhou (%) Shenzhen (%)
≤ 1 month 30 (27.9) 9 (43.8) 8 (33.3) 2 (9.5) 10 (29.0)
> 1 ≤ 3 months 28 (26.7) 1 (6.3) 7 (27.8) 4 (14.3) 16 (45.2)
> 3 ≤ 6 months 20 (18.6) 4 (18.8) 3 (11.1) 10 (38.1) 3 (9.7)
> 6 ≤ 12 months 14 (12.8) 3 (12.5) 4 (16.7) 6 (23.8) 1 (3.2)
> 1 ≤ 2 years 7 (7.0) 1 (6.3) 3 (11.1) 1 (4.8) 2 (6.5)
> 2 ≤ 3 years 6 (5.8) 3 (12.5) 0 (0.0) 1 (4.8) 2 (6.5)
> 3 years 1 (1.2) 0 (0.0) 0 (0.0) 1 (4.8) 0 (0.0)

Daily cigarette consumption of the dual users before and after using ECs are shown in Table 8. According to the data of the four cities and in total, the number of cigarettes smoked per day decreased significantly after the participants’ starting to use ECs. The use of e-cigarettes affected the choice of cigarettes smoked by dual users concerning “tar” content. After using e-cigarettes, the proportion of people smoking low “tar” cigarettes increased from 16.4% to 30.6% (Table 9). There was a significant increase in the number of dual users smoking cigarettes with “tar” yields below 6 mg (X2 = 34.064, p < 0.001). The proportion of people smoking low “tar” cigarettes was the same in each city.

Cig/day of dual users before and after using ECs.

Cigarettes/day (X̅ ± SD) t p

Before using ECs After using ECs
Total 14.20 ± 8.85 8.23 ± 4.95 14.08 < 0.001
Beijing 18.67 ± 11.19 9.27 ± 4.95 5.40 < 0.001
Shanghai 14.97 ± 8.43 8.20 ± 4.95 4.65 < 0.001
Guangzhou 18.08 ± 8.44 9.60 ± 5.29 9.95 < 0.001
Shenzhen 14.07 ± 7.62 8.04 ± 4.42 9.16 < 0.001

EC perception

Proportion of dual users before and after using ECs by cigarette “tar” bands, n (%).

The number of dual users smoking cigarettes containing different concentrations of “tar” X2 p

< 6 6 – 8 9 – 11
Total before using ECs 84 (16.4) 132 (25.8) 268 (52.4) 34.064 0.000
after using ECs 156 (30.6) 158 (30.9) 197 (38.5)

Beijing before using ECs 22 (27.1) 17 (20.8) 43 (52.1) 6.650 0.036
after using ECs 34 (41.7) 21 (25.0) 27 (33.3)

Shanghai before using ECs 18 (14.7) 39 (32.0) 59 (48.0) 9.996 0.007
after using ECs 34 (28.0) 49 (40.0) 39 (32.0)

Guangzhou before using ECs 19 (13.0) 46 (31.0) 77 (52.0) 11.047 0.004
after using ECs 37 (25.0) 58 (39.0) 54 (36.0)

Shenzhen before using ECs 25 (15.9) 29 (18.7) 88 (56.11) 9.269 0.010
after using ECs 51 (32.7) 31 (19.6) 75 (47.7)

The reasons for initiating EC use were analyzed in Table 10. Some reasons for use initiation were reported as: “to quit smoking”, “to reduce smoke-related exposure to family members”, “to avoid smoking bans in public places”, “the choice of multiple flavors in ECs”, “to pursue fashion or curiosity”, “economic reasons”, “to make smoke rings”, “to pursue a healthy lifestyle”, or “living abroad for a long time”. Participants were permitted to provide more than one reason for use initiation. Most people stated that quitting smoking and reducing the exposure of family members to cigarette smoke were their most important reasons for starting EC use. The proportions were 74.8% and 49.9% respectively. 69.5% of the participants came into contact with ECs through relatives, friends, or colleagues for the first time. Other ways to get to know e-cigarettes are traditional advertising, articles, online advertisements, EC experience stores or shops, and WeChat circles. More than half of the participating EC users (51.3%) believe there is no harm at all in ECs although 9.4% participants thought ECs are less harmful than traditional cigarettes. But 88.6% of the participants were unsure whether ECs were less harmful than cigarettes. A majority of participants (60.5%) considered that using ECs could help to quit smoking and them using ECs began as a way to stop smoking cigarettes. When using ECs in public places, 46.8% of the users thought that it would not cause health impacts on the surrounding non-smokers through second-hand vaping. But 31.0% of the participants considered that using ECs may affect nearby non-smokers. Participants stated that they gained information on health effects of ECs from different sources: by consulting professional books or scientific literature (28.4%), from the internet (27.3%), or from information provided by acquaintances (29.8%). The majority of the participants (62.7%) expressed an openness to communicate frequently with others about the products, flavors, usage, and related information.

Perception of ECs among the users.

E-cigarette perception Proportion n (%)
Reasons given for initiating EC use To quit smoking 382 (74.8)
To reduce the exposure to cigarette smoke of family members 255 (49.9)
To avoid a smoking ban in public places 221 (43.2)
Multiple flavors in ECs 204 (39.9)
For reasons of fashion or curiosity 198 (38.7)
Economic reasons 9 (1.8)
To make smoke rings 2 (0.4)
To pursue a healthy lifestyle 2 (0.4)
Due to living abroad for a long time 1 (0.2)

First contact with EC Introduced by relatives, friends, or colleagues 355 (69.5)
Advertising in print articles or online 65 (12.7)
EC experience store or EC shop 60 (11.7)
WeChat friends circle 24 (4.7)
Outdoor advertising 7 (1.4)

ECs are less harmful than traditional cigarettes Yes 48 (9.4)
No 11 (2.2)
I don’t know 453 (88.6)

Is there any risk of harm from ECs? Yes 38 (7.5)
No 262 (51.3)
I don’t know 210 (41.1)

Ability to quit smoking by using ECs I can quit 309 (60.5)
I can’t quit 69 (13.6)
I don’t know 132 (25.9)

Does using ECs have an effect on people around you who don't smoke Yes 158 (31.0)
No 239 (46.8)
I don’t know 113 (22.2)

The most persuasive channel for “information on the health effects of ECs” Consulting professional books or scientific literature 145 (28.4)
Searching for information on the Internet 140 (27.3)
Introduction by acquaintances 152 (29.8)
Related materials provided by retail stores 74 (14.5)

Channels to communicate on products, taste, smoking and other related information with other consumers who use ECs Friends and colleagues who use ECs 320 (62.7)
EC-related BBS* and WeChat groups 74 (14.5)
EC experience store 94 (18.3)
No communication 23 (4.5)

BBS: Bulletin Board System

Effects on health and family

As shown in Table 11, a small number of participants experienced side effects. Reported side effects included: irritation to the mouth (21.5%) and adverse respiratory effects (56.6%). After using ECs for 3 months, 42.3% of the participants felt better about their overall health as defined by factors such as: weight, sleep quality, memory, or sense of smell. Simultaneously 50.5% of the participants claimed that their family and friends supported their use of ECs.

Health effects and family response reported by EC users.

Health effects Proportion n (%)
Irritating to the mouth Yes 110 (21.5)
No 381 (74.6)
I don’t know 20 (3.9)

Adverse respiratory effects (e.g. pharyngitis, cough, irritation, etc.) Better 289 (56.6)
No change 218 (42.7)
Worse 4 (0.8)

Changes in body and body functions (e.g. weight, sleep quality, memory, sense of smell etc.) after using ECs for 3 months Better 216 (42.3)
No change 291 (56.9)
Worse 4 (0.8)

Attitudes of families and friends towards the use of ECs Supportive 258 (50.5)
Adverse 25 (4.9)
No opinion 228 (44.6)
DISCUSSION

Since the emergence of ECs on the market, there has been widespread interest and attention from traditional cigarette smokers. However, Chinese domestic attention to the use of ECs is generally low and the research on ECs is rare at present. This study is the first questionnaire-based investigation among EC users in China.

Many participants were classified as dual users who still smoked cigarettes while also using ECs; only 19.7% of the participants surveyed were non-smokers prior to use. ECs are popular among young people in Beijing, Shanghai, Guangzhou, and Shenzhen predominately. This may be because young people are generally better educated and receptive to new things.

One Canadian study targeted the previous 30-day use of students in grades 9–12 (2). This Canadian study showed that there was a strong correlation between the use of ECs and cigarette smoking.

Although most adult smokers reported they were using ECs to quit smoking or to reduce their cigarette smoking, there were also about 20% of young people aged 15–19 who also used ECs. Lee et al. conducted a survey of reasons for and frequency of EC use among young people aged 13–18 years, in South Korea (8). The survey showed that young smokers believe that ECs can facilitate withdrawal from cigarette smoking.

DAI and HAO conducted a study on the use of scented ECs among middle and high school students in the United States (9). The study found that the use of flavored ECs could increase the risk of initiation to smoking among teens and young adults with no prior history of smoking. These studies all focused on young people, and demonstrated the relationship between socio-demographic characteristics and EC use.

Li et al. also demonstrated that the rate of EC use among the group aged 25–44 years (59.23%) was significantly higher than that of other age groups (7). Young people tend to accept and try new things readily, especially when they were recommended by friends. This study demonstrated that most EC users came into contact with an EC for the first time through introduction by friends or relatives. Furthermore, most EC users often had a higher education level compared with traditional cigarette smokers (7).

At present, the ECs on the market come as prefilled cartridge systems and refill systems (10). A pre-filled EC is an integrated system, which consists of a receptacle pre-filled with EC liquid, batteries, and an atomizer. Components of a pre-filled EC are not replaceable, and the unit is disposable. Refillable units can be re-filled with EC liquid by the user. These re-usable units are easy to use and relatively low in price, making them first choice for more than 90% of all users. Unlike traditional cigarettes, ECs have a variety of flavors, providing a pleasant experience for users and, in turn, a sense of increasing satisfaction and fun. Soule et al. surveyed 114 of the most popular flavors (11). Flavor was grouped into four categories: food/desserts/spices (36.8%), fruit (36.0%), tobacco or menthol (14.9%), and others or a combination of flavors (12.3%). Our study found that the majority of users preferred fruit and food flavors.

People who use ECs are predominantly dual users. Further, those who smoke traditional cigarettes are more likely to use ECs as well. ECs can attract non-smokers to try ECs. In particular, the adults using ECs claimed that the craving for nicotine would be alleviated, and they could use ECs where smoking was not allowed or use them to quit smoking. Users have identified ECs as a means to have access to vaping at any time, with an added benefit of limitless flavors (12). A survey of 46 traditional cigarette users found that approximately three out of four people surveyed admitted to use ECs on all 30 days of the month past (11). The data suggested that the most important reasons to start using ECs were to reduce or completely quit smoking (74.8%) and to reduce the exposure of family members to second-hand smoke. Some studies also found that smoking cessation or reduction was the primary reason for using ECs (13,14,15,16). These studies are consistent throughout the current amount of knowledge on this topic. The second most frequent purpose of use was to reduce health risks (13, 14). Other frequently cited factors for selecting ECs were the lower costs compared to that of traditional cigarettes as well as the public smoking ban (17, 18).

The symptoms of a dry mouth and throat were reported by our study participants, which may be associated with the water-absorbing properties of propylene glycol and glycerol, the main constituents of the EC liquid. Typically, users have defined these side effects as minimal when compared with the other physiological benefits (19,20,21).

Our survey also found that 74.6% of the users believed that EC use was not irritating to the mouth. One study of 19,000 users found that more than 90% of traditional cigarette smokers felt an improvement or static changes to their adverse respiratory effects (pharyngitis, cough, and irritation, etc.) and other physical health conditions when switching to ECs (22). These results are consistent with our findings in this study. Moreover, most participants’ families expressed support or no adverse opinion about EC use. A longitudinal study conducted by ETTER and BULLEN found that 46% of dual users quit smoking successfully after a year of follow-up (23).

Overall, this EC population survey demonstrates that young people are the main users of ECs. A great variety of flavors in ECs attracts people of all ages. The perceived characteristics of ECs, such as stylishness and fun, can attract smokers to choose ECs. With dual users, the use of ECs may reduce their use of traditional cigarettes and encourage them to choose cigarettes with lower nicotine concentrations. Most smokers considered that ECs could be used in no-smoking environments and that they lower the harm risk to family members.

Figure 1

Occupational distribution in cities and total (%).
Occupational distribution in cities and total (%).

Daily usage of ECs and EC liquid by age groups.

User behaviour Age group (years) X̅ ± SD
Frequency per day (times/day) 18 – 29 88.3 ± 88.3
30 – 39 83.0 ± 88.1
40 – 49 64.0 ± 75.2
Over 50 62.0 ± 73.0
Volume of EC liquid per day (mL/day) 18 – 29 7.2 ± 7.3
30 – 39 6.0 ± 6.0
40 – 49 3.4 ± 4.4*
Over 50 2.5 ± 1.8*

Smoking cessation among EC users (%).

Smoking cessation within Total (%) Beijing (%) Shanghai (%) Guangzhou (%) Shenzhen (%)
≤ 1 month 30 (27.9) 9 (43.8) 8 (33.3) 2 (9.5) 10 (29.0)
> 1 ≤ 3 months 28 (26.7) 1 (6.3) 7 (27.8) 4 (14.3) 16 (45.2)
> 3 ≤ 6 months 20 (18.6) 4 (18.8) 3 (11.1) 10 (38.1) 3 (9.7)
> 6 ≤ 12 months 14 (12.8) 3 (12.5) 4 (16.7) 6 (23.8) 1 (3.2)
> 1 ≤ 2 years 7 (7.0) 1 (6.3) 3 (11.1) 1 (4.8) 2 (6.5)
> 2 ≤ 3 years 6 (5.8) 3 (12.5) 0 (0.0) 1 (4.8) 2 (6.5)
> 3 years 1 (1.2) 0 (0.0) 0 (0.0) 1 (4.8) 0 (0.0)

Health effects and family response reported by EC users.

Health effects Proportion n (%)
Irritating to the mouth Yes 110 (21.5)
No 381 (74.6)
I don’t know 20 (3.9)

Adverse respiratory effects (e.g. pharyngitis, cough, irritation, etc.) Better 289 (56.6)
No change 218 (42.7)
Worse 4 (0.8)

Changes in body and body functions (e.g. weight, sleep quality, memory, sense of smell etc.) after using ECs for 3 months Better 216 (42.3)
No change 291 (56.9)
Worse 4 (0.8)

Attitudes of families and friends towards the use of ECs Supportive 258 (50.5)
Adverse 25 (4.9)
No opinion 228 (44.6)

The differences of the use patterns among age groups, n (%).

Total Age 18 – 29 years Age 30 – 39 years Age 40 – 49 years Age over 50 years F p
Flavor preference Fruit 294 (59.9) 173 (73.3) 79 (48.2) 34 (51.5) 8 (32.0) 70.487 < 0.001
Tobacco 101 (20.6) 23 (9.7) 42 (25.6) 28 (42.4) 8 (32.0)
Cigar 7 (1.4) 1 (0.4) 5 (3.0) 1 (1.5) 0 (0.0)
Chocolate 5 (1.0) 1 (0.4) 3 (1.8) 0 (0.0) 1 (4.0)
Menthol 62 (12.6) 26 (11.0) 27 (16.5) 2 (3.0) 7 (28.0)
Others 22 (4.5) 12 (5.1) 8 (4.9) 1 (1.5) 1 (4.0)

Nicotine concentration 0 mg/mL 85 (17.3) 34 (14.4) 29 (17.7) 14 (21.2) 8 (32.0) 51.874 < 0.001
Low 284 (57.8) 164 (69.5) 88 (53.7) 23 (34.8) 9 (36.0)
Moderate 77 (15.7) 20 (8.5) 36 (22.0) 17 (25.8) 4 (16.0)
High 13 (2.6) 5 (2.1) 2 (1.2) 5 (7.6) 1 (4.0)
≥20 mg/mL 1 (0.2) 0 (0.0) 0 (0.0) 1 (1.5) 0 (0.0)
Don’t know 31 (6.3) 13 (5.5) 9 (5.5) 6 (9.1) 3 (12.0)

Duration of use 3 – 6 months 75 (15.3) 42 (17.8) 17 (10.4) 14 (21.2) 2 (8.0) 34.793 0.003
6 – 12 months 149 (30.3) 81 (34.3) 39 (23.8) 21 (31.8) 8 (32.0)
1 – 2 years 172 (35.0) 73 (30.9) 78 (47.6) 14 (21.2) 7 (28.0)
2 – 3 years 57 (11.6) 30 (12.7) 16 (9.8) 8 (12.1) 3 (12.0)
3 – 5 years 23 (4.7) 6 (2.5) 8 (4.9) 6 (9.1) 3 (12.0)
> 5 years 15 (3.1) 4 (1.7) 6 (3.7) 3 (4.5) 2 (8.0)

Frequency of use in past 30 days 3 – 4 days/week 89 (18.1) 41 (17.4) 32 (19.5) 11 (16.7) 5 (20.0) 4.731 0.579
5 – 6 days/week 89 (18.1) 42 (17.8) 28 (17.1) 17 (25.8) 2 (8.0)
per day 313 (63.8) 153 (64.8) 104 (63.4) 38 (57.6) 18 (72.0)

Basic distribution of EC users, n (%).

Characteristics Classification Number of participants (%)

Total Beijing Shanghai Guangzhou Shenzhen
Age (years) 18–29 243 (47.6) 38 (46.3) 42 (34.1) 44 (29.5) 119 (75.8)
30–39 175 (34.2) 30 (36.6) 57 (46.3) 72 (48.3) 16 (10.2)
40–49 67 (13.1) 7 (8.5) 18 (14.6) 22 (14.8) 20 (12.7)
Above 50 26 (5.1) 7 (8.5) 6 (4.9) 11 (7.4) 2 (1.3)

Gender Male 463 (90.6) 76 (92.7) 104 (84.6) 131 (87.9) 152 (96.8)
Female 48 (9.4) 6 (7.3) 19 (15.4) 18 (12.1) 5 (3.2)

Education Doctoral 1 (0.2) 1 (1.2) 0 (0.0) 0 (0.0) 0 (0.0)
Master 6 (1.2) 5 (6.1) 1 (0.8) 0 (0.0) 0 (0.0)
Bachelor 231 (45.2) 55 (67.1) 76 (61.8) 68 (45.6) 32 (20.4)
Associate degree 184 (36.0) 13 (15.9) 36 (29.3) 57 (38.3) 78 (49.7)
High School 86 (16.8) 8 (9.8) 10 (8.1) 22 (14.8) 46 (29.3)
Others 3 (0.6) 0 (0.0) 0 (0.0) 2 (1.3) 1 (0.6)

Occupation General staff 145 (28.4) 24 (39.3) 43 (35.0) 43 (28.9) 35 (22.3)
Middle or senior level management 119 (23.3) 16 (19.5) 41 (33.3) 47 (31.5) 15 (9.6)
Students 70 (13.7) 7 (8.5) 3 (2.4) 2 (1.3) 58 (36.9)
Freelancers 51 (10.0) 13 (15.9) 10 (8.1) 12 (8.1) 16 (10.2)
Private business owners / Partners 44 (8.6) 7 (8.5) 11 (8.9) 16 (10.9) 10 (6.4)
General staff of Government Departments / Institutions 24 (4.7) 2 (2.4) 6 (4.9) 12 (8.1) 4 (2.5)
Blue-collar workers in a servicebranch (e.g., restaurants or shops) 12 (2.3) 3 (3.7) 1 (0.8) 2 (1.3) 6 (3.8)
Middle or senior level management in Government Departments / Institutions 11 (2.2) 2 (2.4) 3 (2.4) 1 (0.7) 5 (3.2)
Owners of small shops / restaurants, etc. 10 (2.0) 0 (0.0) 1 (0.8) 6 (4.1) 3 (1.9)
Labourers / blue-collar / manual workers 10 (2.0) 2 (2.4) 1 (0.8) 4 (2.7) 3 (1.9)
Middle / senior level professionals (e.g., lawyers, doctors, scientists, etc.) 9 (1.8) 3 (3.7) 2 (1.6) 3 (2.0) 1 (0.6)
Retired 3 (0.6) 1 (1.2) 1 (0.8) 1 (0.7) 0 (0.0)
Unemployed / laid off 3 (0.6) 2 (2.4) 0 (0.0) 0 (0.0) 1 (0.6)

Types of e-cigarettes used in the four cities.

Classification Number of participants (%)

Total Beijing Shanghai Guangzhou Shenzhen
Cartomized 491 (96.1) 80 (97.6) 113 (91.9) 147 (98.7) 151 (96.2)
Tank 15 (2.9) 2 (2.4) 9 (7.3) 2 (1.3) 2 (1.3)
Disposable 5 (1.0) 0 (0) 1 (0.8) 0 (0) 4 (2.5)

Usage status of tobacco products, n (%).

Product usage Total Beijing Shanghai Guangzhou Shenzhen
EC only 137 (26.8) 21 (25.6) 31 (25.2) 42 (28.2) 43 (27.4)
Dual usage 374 (73.2) 61 (74.4) 92 (74.8) 107 (71.8) 114 (72.6)

Proportion of dual users before and after using ECs by cigarette “tar” bands, n (%).

The number of dual users smoking cigarettes containing different concentrations of “tar” X2 p

< 6 6 – 8 9 – 11
Total before using ECs 84 (16.4) 132 (25.8) 268 (52.4) 34.064 0.000
after using ECs 156 (30.6) 158 (30.9) 197 (38.5)

Beijing before using ECs 22 (27.1) 17 (20.8) 43 (52.1) 6.650 0.036
after using ECs 34 (41.7) 21 (25.0) 27 (33.3)

Shanghai before using ECs 18 (14.7) 39 (32.0) 59 (48.0) 9.996 0.007
after using ECs 34 (28.0) 49 (40.0) 39 (32.0)

Guangzhou before using ECs 19 (13.0) 46 (31.0) 77 (52.0) 11.047 0.004
after using ECs 37 (25.0) 58 (39.0) 54 (36.0)

Shenzhen before using ECs 25 (15.9) 29 (18.7) 88 (56.11) 9.269 0.010
after using ECs 51 (32.7) 31 (19.6) 75 (47.7)

Perception of ECs among the users.

E-cigarette perception Proportion n (%)
Reasons given for initiating EC use To quit smoking 382 (74.8)
To reduce the exposure to cigarette smoke of family members 255 (49.9)
To avoid a smoking ban in public places 221 (43.2)
Multiple flavors in ECs 204 (39.9)
For reasons of fashion or curiosity 198 (38.7)
Economic reasons 9 (1.8)
To make smoke rings 2 (0.4)
To pursue a healthy lifestyle 2 (0.4)
Due to living abroad for a long time 1 (0.2)

First contact with EC Introduced by relatives, friends, or colleagues 355 (69.5)
Advertising in print articles or online 65 (12.7)
EC experience store or EC shop 60 (11.7)
WeChat friends circle 24 (4.7)
Outdoor advertising 7 (1.4)

ECs are less harmful than traditional cigarettes Yes 48 (9.4)
No 11 (2.2)
I don’t know 453 (88.6)

Is there any risk of harm from ECs? Yes 38 (7.5)
No 262 (51.3)
I don’t know 210 (41.1)

Ability to quit smoking by using ECs I can quit 309 (60.5)
I can’t quit 69 (13.6)
I don’t know 132 (25.9)

Does using ECs have an effect on people around you who don't smoke Yes 158 (31.0)
No 239 (46.8)
I don’t know 113 (22.2)

The most persuasive channel for “information on the health effects of ECs” Consulting professional books or scientific literature 145 (28.4)
Searching for information on the Internet 140 (27.3)
Introduction by acquaintances 152 (29.8)
Related materials provided by retail stores 74 (14.5)

Channels to communicate on products, taste, smoking and other related information with other consumers who use ECs Friends and colleagues who use ECs 320 (62.7)
EC-related BBS* and WeChat groups 74 (14.5)
EC experience store 94 (18.3)
No communication 23 (4.5)

Cig/day of dual users before and after using ECs.

Cigarettes/day (X̅ ± SD) t p

Before using ECs After using ECs
Total 14.20 ± 8.85 8.23 ± 4.95 14.08 < 0.001
Beijing 18.67 ± 11.19 9.27 ± 4.95 5.40 < 0.001
Shanghai 14.97 ± 8.43 8.20 ± 4.95 4.65 < 0.001
Guangzhou 18.08 ± 8.44 9.60 ± 5.29 9.95 < 0.001
Shenzhen 14.07 ± 7.62 8.04 ± 4.42 9.16 < 0.001

The history of cigarette smoking for EC-only users and dual users, n (%).

User of: User history/status Total Beijing Shanghai Guangzhou Shenzhen
ECs only Always using ECs only 101 (19.7) 12 (14.3) 32 (25.8) 43 (28.6) 15 (9.3)
Smoker before using ECs only 410 (80.3) 70 (85.7) 91 (74.2) 106 (71.4) 142 (90.7)
Dual usage Smoker before using ECs 451 (88.2) 65 (78.7) 100 (81.5) 139 (93.5) 147 (93.9)
Nonsmoker before using ECs 60 (11.8) 17 (21.3) 23 (18.5) 10 (6.5) 10 (6.1)

Framework Convention Alliance (FCA): FCA Policy Briefing. Electronic Nicotine Delivery Systems; Presented at the Sixth Session of the Conference of the Parties to the WHO Framework Convention on Tobacco Control, 13–18 October 2014, Moscow, Russia. Available at: https://www.fctc.org/fca-policy-briefing-electronic-nicotine-delivery-systems/ (accessed July, 2021) Framework Convention Alliance (FCA) FCA Policy Briefing. Electronic Nicotine Delivery Systems Presented at the Sixth Session of the Conference of the Parties to the WHO Framework Convention on Tobacco Control 13–18 October 2014 Moscow, Russia Available at: https://www.fctc.org/fca-policy-briefing-electronic-nicotine-delivery-systems/ (accessed July, 2021) Search in Google Scholar

Hammond, D., J.L. Reid, A.G. Cole, and S.T. Leatherdale: Electronic Cigarette Use and Smoking Initiation Among Youth: A Longitudinal Cohort Study; Can. Med. Assoc. J. 189 (2017) E1328–E1336. DOI: 10.1503/cmaj.161002 HammondD. ReidJ.L. ColeA.G. LeatherdaleS.T. Electronic Cigarette Use and Smoking Initiation Among Youth: A Longitudinal Cohort Study Can. Med. Assoc. J. 189 2017 E1328 E1336 10.1503/cmaj.161002 566244929084759 Otwórz DOISearch in Google Scholar

Reid, J.L., V.L. Rynard, C.D. Czoli, and D. Hammond: Who is Using E-Cigarettes in Canada? Nationally Representative Data on the Prevalence of E-Cigarette Use Among Canadians; Prev. Med. 81 (2015) 180–183. DOI: 10.1016/j.ypmed.2015.08.019 ReidJ.L. RynardV.L. CzoliC.D. HammondD. Who is Using E-Cigarettes in Canada? Nationally Representative Data on the Prevalence of E-Cigarette Use Among Canadians Prev. Med. 81 2015 180 183 10.1016/j.ypmed.2015.08.019 26348453 Otwórz DOISearch in Google Scholar

Barnett, T.E., E.K. Soule, J.R. Forrest, L. Porter, and S.L. Tomar: Adolescent Electronic Cigarette Use: Associations with Conventional Cigarette and Hookah Smoking; Am. J. Prev. Med. 49 (2015) 199–206. DOI: 10.1016/j.amepre.2015.02.013 BarnettT.E. SouleE.K. ForrestJ.R. PorterL. TomarS.L. Adolescent Electronic Cigarette Use: Associations with Conventional Cigarette and Hookah Smoking Am. J. Prev. Med. 49 2015 199 206 10.1016/j.amepre.2015.02.013 25840880 Otwórz DOISearch in Google Scholar

Barrington-Trimis, J.L., R. Urman, A.M. Leventhal, W.J. Gauderman, T.B. Cruz, T.D. Gilreath, S. Howland, J.B. Unger, K. Berhane, J.M. Samet, and R. McConnell: E-Cigarettes, Cigarettes, and the Prevalence of Adolescent Tobacco Use; Pediatrics 138 (2016) e20153983. DOI: 10.1542/peds.2015-3983 Barrington-TrimisJ.L. UrmanR. LeventhalA.M. GaudermanW.J. CruzT.B. GilreathT.D. HowlandS. UngerJ.B. BerhaneK. SametJ.M. McConnellR. E-Cigarettes, Cigarettes, and the Prevalence of Adolescent Tobacco Use Pediatrics 138 2016 e20153983 10.1542/peds.2015-3983 496072327401102 Otwórz DOISearch in Google Scholar

Li, S.S., D. Xiao, S.L. Chu, H.Y. Qin, and C. Wang: Investigation on the Use of E-Cigarettes among cigarette smokers in Beijing; Chin. Clin. J. 43 (2015) 47–99. [in Chinese] DOI: 10.3969/j.issn.2095-8552.2015.03.015 LiS.S. XiaoD. ChuS.L. QinH.Y. WangC. Investigation on the Use of E-Cigarettes among cigarette smokers in Beijing Chin. Clin. J. 43 2015 47 99 [in Chinese] 10.3969/j.issn.2095-8552.2015.03.015 Otwórz DOISearch in Google Scholar

Li, W., G. Jiang, Z. Xu, W. Zheng, W. Shen, X. Xue, and Y. Yang: Analysis on the Results of the Investigation on the Use of Electronic Cigarettes by Urban Residents in Tianjin; Chin. J. Prev. Contr. Chron. Dis. 24 (2016) 509–511. Avaliable at: http://caod.oriprobe.com/articles/49020937/tian_jin_shi_cheng_shi_ju_min_dian_zi_yan_shi_yong_qing_kuang_diao_cha.htm LiW. JiangG. XuZ. ZhengW. ShenW. XueX. YangY. Analysis on the Results of the Investigation on the Use of Electronic Cigarettes by Urban Residents in Tianjin Chin. J. Prev. Contr. Chron. Dis. 24 2016 509 511 Avaliable at: http://caod.oriprobe.com/articles/49020937/tian_jin_shi_cheng_shi_ju_min_dian_zi_yan_shi_yong_qing_kuang_diao_cha.htm Search in Google Scholar

Lee, J.A., S. Lee, and H.J. Cho: The Relation between Frequency of E-Cigarette Use and Frequency and Intensity of Cigarette Smoking Among South Korean Adolescents; Int. J. Environ. Res. Public Health. 14 (2017) 305. DOI:10.3390/ijerph14030305 LeeJ.A. LeeS. ChoH.J. The Relation between Frequency of E-Cigarette Use and Frequency and Intensity of Cigarette Smoking Among South Korean Adolescents Int. J. Environ. Res. Public Health. 14 2017 305 10.3390/ijerph14030305 536914128335449 Otwórz DOISearch in Google Scholar

Dai H. and J. Hao: Flavored Electronic Cigarette Use and Smoking Among Youth; Pediatrics 138 (2016) e20162513–e20162513. DOI:10.1542/peds.2016–2513. DaiH. HaoJ. Flavored Electronic Cigarette Use and Smoking Among Youth Pediatrics 138 2016 e20162513 e20162513 10.1542/peds.2016–2513 Otwórz DOISearch in Google Scholar

Berg, C.J.: Preferred Flavors and Reasons for E-Cigarette Use and Discontinued Use Among Never, Current, and Former Smokers; Int. J. Public Health 2 (2016) 225–236. DOI: 10.1007/s00038-015-0764-x BergC.J. Preferred Flavors and Reasons for E-Cigarette Use and Discontinued Use Among Never, Current, and Former Smokers Int. J. Public Health 2 2016 225 236 10.1007/s00038-015-0764-x 480847326582009 Otwórz DOISearch in Google Scholar

Soule, E.K., A.A. Lopez, M.C. Guy, and C.O. Cobb: Reasons for Using Flavored Liquids Among Electronic Cigarette Users: A Concept Mapping Study; Drug Alcohol Depend. 166 (2016) 168–176. DOI: 10.1016/j.drugalcdep.2016.07.007 SouleE.K. LopezA.A. GuyM.C. CobbC.O. Reasons for Using Flavored Liquids Among Electronic Cigarette Users: A Concept Mapping Study Drug Alcohol Depend. 166 2016 168 176 10.1016/j.drugalcdep.2016.07.007 498351927460860 Otwórz DOISearch in Google Scholar

Kim, H., A.H. Davis, J.L. Dohack, and P.I. Clark: E-Cigarettes Use Behavior and Experience of Adults: Qualitative Research Findings to Inform E-Cigarette Use Measure Development; Nicotine Tob. Res. 19 (2017) 190–196. DOI: 10.1093/ntr/ntw175 KimH. DavisA.H. DohackJ.L. ClarkP.I. E-Cigarettes Use Behavior and Experience of Adults: Qualitative Research Findings to Inform E-Cigarette Use Measure Development Nicotine Tob. Res. 19 2017 190 196 10.1093/ntr/ntw175 523435927613944 Otwórz DOISearch in Google Scholar

Adkison, S.E., R.J. O’Connor, M. Bansal-Travers, A. Hyland, R. Borland, H.H. Yong, K.M. Cummings, A. McNeill, J.F. Thrasher, D. Hammond, and G.T. Fong: Electronic Nicotine Delivery Systems: International Tobacco Control Four-Country Survey; Am. J. Prev. Med. 44 (2013) 207–215. DOI: 10.1016/j.amepre AdkisonS.E. O’ConnorR.J. Bansal-TraversM. HylandA. BorlandR. YongH.H. CummingsK.M. McNeillA. ThrasherJ.F. HammondD. FongG.T. Electronic Nicotine Delivery Systems: International Tobacco Control Four-Country Survey Am. J. Prev. Med. 44 2013 207 215 10.1016/j.amepre Otwórz DOISearch in Google Scholar

Berg, C.J., R. Haardoerfer, C. Escoffery, P. Zheng, and M. Kegler: Cigarette Users’ Interest in Using or Switching to Electronic Nicotine Delivery Systems for Smokeless Tobacco for Harm Reduction, Cessation, or Novelty: A Cross-Sectional Survey of US Adults; Nicotine Tob. Res. 17 (2015) 245–255. DOI: 10.1093/ntr/ntu103 BergC.J. HaardoerferR. EscofferyC. ZhengP. KeglerM. Cigarette Users’ Interest in Using or Switching to Electronic Nicotine Delivery Systems for Smokeless Tobacco for Harm Reduction, Cessation, or Novelty: A Cross-Sectional Survey of US Adults Nicotine Tob. Res. 17 2015 245 255 10.1093/ntr/ntu103 431117224951496 Otwórz DOISearch in Google Scholar

Brown, J., R. West, E. Beard, S. Michie, L. Shahab, and A. McNeill: Prevalence and Characteristics of E-Cigarette Users in Great Britain: Findings From a General Population Survey of Smokers; Addict. Behav. 39 (2014) 1120–1125. DOI: 10.1016/j.addbeh.2014.03.009 BrownJ. WestR. BeardE. MichieS. ShahabL. McNeillA. Prevalence and Characteristics of E-Cigarette Users in Great Britain: Findings From a General Population Survey of Smokers Addict. Behav. 39 2014 1120 1125 10.1016/j.addbeh.2014.03.009 400353224679611 Otwórz DOISearch in Google Scholar

Goniewicz, M.L., E.O. Lingas, and P. Hajek: Patterns of Electronic Cigarette Use and User Beliefs About Their Safety and Benefits: An Internet Survey; Drug Alcohol Rev. 32 (2013) 133–140. DOI: 10.1111/j.1465-3362.2012.00512.x GoniewiczM.L. LingasE.O. HajekP. Patterns of Electronic Cigarette Use and User Beliefs About Their Safety and Benefits: An Internet Survey Drug Alcohol Rev. 32 2013 133 140 10.1111/j.1465-3362.2012.00512.x 353063122994631 Otwórz DOISearch in Google Scholar

Kadimpati, S., M. Nolan, and D.O. Warner: Attitudes, Beliefs, and Practices Regarding Electronic Nicotine Delivery Systems in Patients Scheduled for Elective Surgery; Mayo. Clin. Proc. 90 (2015) 71–76. DOI: 10.1016/j.mayocp.2014.11.005 KadimpatiS. NolanM. WarnerD.O. Attitudes, Beliefs, and Practices Regarding Electronic Nicotine Delivery Systems in Patients Scheduled for Elective Surgery Mayo. Clin. Proc. 90 2015 71 76 10.1016/j.mayocp.2014.11.005 25572195 Otwórz DOISearch in Google Scholar

Soule, E.K., S.R. Rosas, and A. Nasim: Reasons for Electronic Cigarette Use Beyond Smoking Cessation: A Concept Mapping Approach; Addict. Behav. 56 (2016) 41–50. DOI: 10.1016/j.addbeh.2016.01.008 SouleE.K. RosasS.R. NasimA. Reasons for Electronic Cigarette Use Beyond Smoking Cessation: A Concept Mapping Approach Addict. Behav. 56 2016 41 50 10.1016/j.addbeh.2016.01.008 475352826803400 Otwórz DOISearch in Google Scholar

Farsalinos, K.E., G. Romagna, D. Tsiapras, S. Kyrzopoulos, and V. Voudris: Evaluating Nicotine Levels Selection and Patterns of Electronic Cigarette Use in a Group of “Vapers” who had Achieved Complete Substitution of Smoking; Subst. Abuse 3 (2013) 139–46. DOI: 10.4137/SART.S12756.6 FarsalinosK.E. RomagnaG. TsiaprasD. KyrzopoulosS. VoudrisV. Evaluating Nicotine Levels Selection and Patterns of Electronic Cigarette Use in a Group of “Vapers” who had Achieved Complete Substitution of Smoking Subst. Abuse 3 2013 139 46 10.4137/SART.S12756.6 Otwórz DOISearch in Google Scholar

Dawkins, L., J. Turner, A. Roberts, and K. Soar: ‘Vaping’ Profiles and Preferences: An Online Survey of Electronic Cigarette Users; Addiction 108 (2013) 1115–1125. DOI: 10.1111/add.12150 DawkinsL. TurnerJ. RobertsA. SoarK. ‘Vaping’ Profiles and Preferences: An Online Survey of Electronic Cigarette Users Addiction 108 2013 1115 1125 10.1111/add.12150 23551515 Otwórz DOISearch in Google Scholar

Etter, J.F. and C. Bullen: Electronic Cigarette: Users Profile, Utilization, Satisfaction and Perceived Efficacy; Addiction 106 (2011) 2017–2028. DOI: 10.1111/j.1360-0443.2011.03505.x EtterJ.F. BullenC. Electronic Cigarette: Users Profile, Utilization, Satisfaction and Perceived Efficacy Addiction 106 2011 2017 2028 10.1111/j.1360-0443.2011.03505.x 21592253 Otwórz DOISearch in Google Scholar

Farsalinos, K.E., G. Romagna, D. Tsiapras, S. Kyrzopoulos, and V. Voudris: Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers; J. Environ. Res. Public Health 11 (2014) 4356–4373. DOI: 10.3390/ijerph110404356 FarsalinosK.E. RomagnaG. TsiaprasD. KyrzopoulosS. VoudrisV. Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers J. Environ. Res. Public Health 11 2014 4356 4373 10.3390/ijerph110404356 402502424758891 Otwórz DOISearch in Google Scholar

Etter, J.F. and C. Bullen: A Longitudinal Study of Electronic Cigarette Users; Addict. Behav. 39 (2014) 491–494. DOI: 10.1016/j.addbeh.2013.10.028 EtterJ.F. BullenC. A Longitudinal Study of Electronic Cigarette Users Addict. Behav. 39 2014 491 494 10.1016/j.addbeh.2013.10.028 24229843 Otwórz DOISearch in Google Scholar

Vaughan, L. and Y. Chen: Data Mining From Web Search Queries: A Comparison of Google Trends and Baidu Index; J. Assn. Inf. Sci. Tec. 66 (2015) 13–22. DOI: 10.1002/asi.23201 VaughanL. ChenY. Data Mining From Web Search Queries: A Comparison of Google Trends and Baidu Index J. Assn. Inf. Sci. Tec. 66 2015 13 22 10.1002/asi.23201 Otwórz DOISearch in Google Scholar

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