Electronic cigarettes in Canada: prevalence of use and perceptions among youth and young adults.
Czoli, Christine D. ; Hammond, David ; White, Christine M. 等
Electronic cigarettes (e-cigarettes) are devices that emit vapour.
(1) E-cigarettes consist of a battery, an automatic or manual switch, an
atomizer with a heating element, and a cartridge that contains a
solution. Solutions, or "e-liquids" or "e-juices",
typically contain propylene glycol or glycerol (or both), and can
contain nicotine, flavours and additives. (2) Both pre-filled and
refillable e-cigarette cartridges are available for sale. (3) In some
models, the atomizer and cartridge are combined into a single unit -a
cartomizer-which is intended to prevent leaking of the solution. (2)
Though e-cigarettes share physical and behavioural similarities with
tobacco cigarettes--resembling them and being handled and used in much
the same way--a key difference is that e-cigarettes do not contain
tobacco and no combustion takes place. As a result, when e-cigarettes
are smoked or "vaped", they emit vapour, but no smoke.
Invented in China in 2003, e-cigarettes entered American and
European markets in 2006, and as of 2012, constituted a global market
valued at $2 billion. (2) The e-cigarette market in the United States
has grown rapidly, with sales tripling every year for the last few
years. (2) In addition, all of the major American tobacco companies have
now publicly announced their entry into the e-cigarette market. (4)
E-cigarettes are commonly marketed and sold over the Internet, and are
becoming increasingly popular. (2,5) In a study examining the popularity
of e-cigarettes, electronic nicotine delivery systems queries in Canada
and other countries increased dramatically, surpassing those of nicotine
replacement therapy by late 2008. (6) The role of the Internet with
respect to the issue of e-cigarettes is particularly relevant for youth
and young adults, who tend to spend more time online than older segments
of the population.
With respect to marketing, the main promise of e-cigarettes is that
they are able to deliver nicotine as ably as cigarettes, thereby serving
as a substitute product. However, this has not yet been demonstrated
scientifically. (7) E-cigarettes are also marketed with claims of health
benefits, such as their lack of cancer-causing chemicals, the absence of
first- or second-hand smoke, the fact that they will not stain teeth or
damage skin, and their use as a quit aid. (7) According to several
studies examining beliefs regarding e-cigarettes, self-reported
perceptions and reasons for use among e-cigarette users mirror these
marketing claims, as many users believe e-cigarettes to be healthier
than regular cigarettes and report using them for this reason. (8-10)
The majority of users believe that e-cigarettes can help people quit
smoking, and many report positive changes in their health (e.g., less
coughing, improved breathing, better physical fitness), and satisfaction
with the use of e-cigarettes, particularly in reference to taste and
flavour. (8) Reporting of adverse events have varied: although serious
events of pneumonia and chest pain were reported to the FDA in the US,
the majority of self-reported side-effects were minor, including dryness
or burning of mouth and throat, light-headedness, headaches, cough, and
phlegm production. (8)
A review of e-cigarette studies indicated that awareness of
e-cigarettes among youth was variable. For instance, only 10% of Korean
youth were aware of e-cigarettes, while 86% of Polish students and 70%
of young adults in the Midwestern US indicated they had ever heard of
e-cigarettes. (8) Reported rates of trial of e-cigarettes among youth
were similarly variable, ranging from less than 1% among male
adolescents in the US in 2011 and among Korean adolescents in 2008, to
21% among Polish high school and university students in 2010-2011.8 A
more recent study of Korean adolescents showed that e-cigarette trial
had increased, with 9% reporting having tried the product in 2011. (11)
Reported rates of current e-cigarette use among youth are consistently
lower, at 1% of young Midwestern US adults in 2010-2011, 2% of North
Carolina college students in 2009, and 7% of Polish high school and
university students in 2010-2011. (8) Research suggests that e-cigarette
use is more common among males, smokers, and those with family or
friends who smoke. (8,11,12)
In Canada, e-cigarettes containing nicotine are prohibited. (13)
However, despite this restriction, e-cigarettes with and without
nicotine are widely available for sale and are becoming increasingly
prominent in various types of retail stores. (3). Anecdotal evidence
suggests that the use of e-cigarettes in Canada is increasing; however,
to date, there is limited research evidence. A single published study
conducted in 2010-2011 found that approximately 40% of former and
current adult smokers in Canada were aware of e-cigarettes and rates of
trial and current use were 4% and 1%, respectively. (14)
The current study sought to examine use of e-cigarettes among
Canadian youth and young adults, including: 1) prevalence of e-cigarette
use, 2) factors associated with e-cigarette use, and 3) perceptions of
e-cigarettes.
METHODS
Study design and protocol
Data were collected as part of a cross-sectional survey conducted
in Canada in July 2012. Following collection of socio-demographic
information, participants were shown an image of an e-cigarette and were
asked to respond to various questions regarding e-cigarettes (described
below). The study received approval from the Office of Research Ethics
at the University of Waterloo.
Participants
Youth and young adults age 16-30 years were recruited through
Global Market Insite, Inc. (GMI), a commercial market research company
with an online panel of Canadians. GMI panel members were sent an e-mail
invitation with a link directly to the survey. Additional information on
GMI's Canadian panel is available online. A total of 1,188
respondents were included in the analyses, after exclusion of
participants with missing information regarding ethnicity (n=10),
education (n=5), smoking status (n=2), and reported trial of
e-cigarettes (n=6).
Measures
Demographic variables included gender, age, ethnicity, and
education level. Ethnicity was classified as White or non-White
(including South Asian, Chinese, Black, Filipino, Latin American, Arab,
Southeast Asian, West Asian, Korean, Japanese, Aboriginal, or
multi-racial). Education level was defined as the highest level of
formal education completed at the time of the study. Education level
categories included: Low (high school or less), Moderate
(technical/trade school, community college, or some university, but no
degree), and High (university degree or more).
"Current smokers" were defined as those who had smoked
100 cigarettes in their lifetime and had smoked in the last 30 days;
"former smokers" had smoked 100 cigarettes in their lifetime
but had not smoked in the last 30 days; and "non-smokers" had
smoked less than 100 cigarettes in their lifetime. E-cigarette smoking
status was determined by asking participants whether they had ever tried
smoking an electronic or smokeless cigarette, and whether they had
smoked an e-cigarette in the last 30 days. E-cigarette
"never-users" had never tried an e-cigarette; e-cigarette
"ever-users" had tried an e-cigarette, but had not smoked one
in the last 30 days; and "current users" of e-cigarettes had
tried an e-cigarette and had smoked one in the last 30 days.
Participants were asked three questions regarding their perceptions
of e-cigarettes: "Is this product harmful to your health?",
"Would you be interested in trying this product?", and
"Should retail outlets, such as corner stores and gas stations, be
allowed to sell this product?" Responses were provided on a scale
from 1 "Not at all" to 10 "Extremely". Exposure to
e-cigarettes was measured by asking participants: "Have you ever
seen e-cigarettes advertised or for sale?", and purchasing of
e-cigarettes by: "Have you ever purchased an e-cigarette?"
Experiences of side-effects or adverse outcomes while using e-cigarettes
was measured by asking e-cigarette ever-users: "Have you ever
experienced any side-effects or adverse outcome(s) while using
e-cigarettes?" E-cigarette ever-users were also asked: "Would
you recommend e-cigarettes to a friend?" Responses were provided on
a scale from 1 "Not at all" to 10 "Extremely".
Current smokers who reported at least some interest in trying
e-cigarettes were asked to indicate their agreement with a list of
potential reasons for using e-cigarettes: in places where you can't
smoke cigarettes; for the times when you don't want to smoke around
others; to help you cut back on the amount you smoke; to help you while
you are trying to quit smoking; as a long-term replacement instead of
cigarettes; as a cheaper alternative to cigarettes. Participants were
asked to respond "Yes", "No" or "Maybe".
Analysis
Differences in the sample profile across smoking status were tested
using chi-square tests for age, sex, ethnicity and education level. Two
logistic regression models were conducted to examine factors associated
with ever use and current use of e-cigarettes. Ever use and current use
of e-cigarettes were measured as binary variables (0,1), where 0
represented participants who had never used or currently did not use
e-cigarettes, and 1 represented participants who had tried or currently
used e-cigarettes. Both models included age, sex, ethnicity, education
level and smoking status as covariates. A second set of models were run
for both outcomes examining all two-way interactions between the
independent variables. Analyses were conducted using SPSS, Version 20
(IBM, Illinois).
RESULTS
Sample characteristics
Sample characteristics are shown in Table 1. Non-smokers, former
smokers and current smokers differed significantly by age ([chi square]
= 86.2, p<0.001), gender ([chi square] = 27.3, p < 0.001), and
ethnicity ([chi square] = 15.6, p<0.001).
Prevalence of e-cigarette use
Prevalence of e-cigarette ever use and current use is summarized in
Table 2. A total of 16.1% reported ever using an e-cigarette (5.2%
non-smokers, 18.9% former smokers, and 34.5% current smokers). Current
use of e-cigarettes was reported by 5.7% (0.8% nonsmokers, 1.4% former
smokers, and 15.0% current smokers).
E-cigarette ever-users (n=191) were asked how likely they were (on
a 10-point scale) to recommend e-cigarettes to a friend. The mean
response was 7.29 ([+ or -] 2.908), and only 9.6% selected "1"
or "Not at all". As well, among e-cigarette ever-users, 12.0%
reported experiencing side-effects or adverse outcomes, while 5.2%
responded "Don't know". Reported side-effects included
headache, nausea, dizziness, dry mouth, sore throat, irritation of the
throat, coughing, wheezing, and vomiting.
Factors associated with e-cigarette use
Table 3 shows the results of logistic regression analyses examining
factors associated with e-cigarette use. As shown in Model 1, ever use
of e-cigarettes was more common among respondents with low compared to
those with high education (OR=2.02, 95% CI: 1.24-3.31; p=0.005). In
addition, ever use of e-cigarettes was significantly more likely among
former smokers than among non-smokers (OR=4.25, 95% CI: 2.11-8.56;
p<0.001), and significantly more likely among current smokers than
among both former smokers (OR=2.32, 95% CI: 1.24-4.35; p=0.009) and
non-smokers (OR=9.84, 95% CI: 6.52-14.86; p<0.001). No interactions
between the independent variables were significantly associated with
ever use of e-cigarettes.
As shown in Model 2, current use of e-cigarettes was more common
among respondents with high compared to those with low education
(OR=4.29, 95% CI: 1.60-11.50; p=0.004). Current use of e-cigarettes was
also significantly more likely among current smokers than among both
former smokers (OR=15.15, 95% CI: 1.80-125.00; p=0.012) and non-smokers
(OR=4.43, 95% CI: 1.6411.94; p=0.003). No interactions between the
independent variables were significantly associated with current use of
e-cigarettes.
E-cigarette exposure
A total of 43.4% reported having seen e-cigarettes advertised or
for sale at one or more of the following locations: on the Internet
(24.3%); in Canada at a regular store, such as a corner store or gas
station (23.1%); outside of Canada (9.5%); or elsewhere (8.6%). A total
of 13.8% reported ever having purchased an e-cigarette at one or more of
the following locations: on the Internet (2.0%); in Canada at a regular
store, such as a corner store or gas station (4.1%); outside of Canada
(0.5%); or elsewhere (0.4%).
Perceptions of e-cigarettes
Figure 1 shows mean reported perceptions of e-cigarettes on a
10-point scale by e-cigarette trial and smoking status. Among
non-smokers and former smokers, perceptions of e-cigarette harm were
lower among e-cigarette ever-users compared to never-users; however,
this pattern was reversed for current smokers. When asked whether they
would be interested in trying e-cigarettes, ever-users consistently
reported greater interest than never-users. Most respondents offered
moderate to high support when asked whether retail outlets should be
allowed to sell e-cigarettes, with the exception of current smokers who
were also never-users of e-cigarettes.
Current smokers reported at least some interest in trying
e-cigarettes (by answering "Yes" or "Maybe", n=378)
for the following reasons: to help cut back on the amount they smoked
(77.7%), as a long-term replacement instead of cigarettes (77.8%), for
the times when they don't want to smoke around others (78.8%), to
help them while they are trying to quit smoking (80.4%), as a cheaper
alternative to cigarettes (80.7%), or in places where they can't
smoke cigarettes (80.9%).
DISCUSSION
The study findings highlight the accessibility and popularity of
e-cigarettes among youth and young adults in Canada. Exposure to
e-cigarettes in our sample was moderate with respect to the literature:
almost half of our sample reported having seen e-cigarettes advertised
or for sale. These findings are higher than those reported among youth
in Korea, but lower than those from the United States and Poland. (8)
However, our findings are similar to levels of awareness recorded among
current and former adult smokers in Canada, in which 40% were aware of
e-cigarettes. (14)
Trial of e-cigarettes in our sample was higher than in the US and
Korea, yet lower than in Poland. (8) Although rates of trial were higher
among former and current smokers, 5.2% of non-smokers in our sample
reported trying e-cigarettes, indicating some interest among youth and
young adults in experimenting with this new product. By comparison, 2011
data from Canadian youth age 15-19 years indicated that one in four
(24.3%) reported having tried a whole cigarette, 27% a cigarillo, and
17% a cigar. (15) Although our study findings were drawn from a
convenience sample, the reported trial of e-cigarettes warrants
attention with respect to patterns of tobacco use among young adults.
Tobacco use emerged as an important and consistent predictor of
e-cigarette use among Canadian youth and young adults. Current smokers
were more likely than non-smokers and former smokers to use or to have
used e-cigarettes, and former smokers were more likely than non-smokers
to have tried e-cigarettes. These findings are consistent with existing
research. (8,12) In contrast, trial of e-cigarettes was not higher among
males in our sample, as has been reported in other studies. (8,12) In
addition, although our analyses showed an interesting pattern with
respect to level of education in that respondents with low were more
likely than those with high education to have tried e-cigarettes,
whereas this pattern was reversed for current use of e-cigarettes--such
associations have not been reported in other studies. (8,12)
Previous studies indicate that most e-cigarette users report using
e-cigarettes to reduce their tobacco cigarette consumption and/or as a
smoking cessation tool. (8) In the current study, smokers reported
similar levels of interest (approximately 80%) in trying e-cigarettes
for a variety of reasons, including: to help cut back on the amount they
smoked, as a long-term replacement instead of cigarettes, for the times
when they don't want to smoke around others, to help them while
they are trying to quit smoking, as a cheaper alternative to cigarettes,
or in places where they can't smoke cigarettes. These findings are
also consistent with e-cigarette marketing trends. (7)
Non-smokers who had not tried e-cigarettes reported little interest
in trying the product, whereas the greatest interest was reported by
current smokers who had tried e-cigarettes. High levels of interest in
trying e-cigarettes among those who have previously tried the product
generally suggest high levels of consumer appeal. Somewhat surprisingly,
among those who had not tried e-cigarettes, reported interest among
former smokers was very similar to that of current smokers. Interest
among former smokers could signal an interest in e-cigarettes as a way
to re-enter the nicotine market. Future research should examine these
perceptions further in order to better understand how these products are
viewed and why they may be used by various subpopulations.
[FIGURE 1 OMITTED]
Strengths and limitations
The findings of this study are subject to various limitations. The
cross-sectional design of the study does not allow for causal inferences
to be drawn between tobacco use and use of e-cigarettes, or for the
determination of the temporality of substance use. In addition, study
participants were not recruited through random sampling. Therefore,
although the sample profile is relatively diverse, it is not
representative of the Canadian population. For example, our study sample
had an unusually high smoking prevalence among females. Although this
was adjusted for in the logistic regression models, it does not reflect
national benchmarks.
For this reason, our findings may suffer from various biases and
should be interpreted with caution.
CONCLUSION
The current study provides the first published evidence of
e-cigarette use among Canadian youth and young adults. The findings
indicate that almost one fifth of youth and young adults surveyed
reported trying e-cigarettes, with evidence of use among non-smokers.
The rapidity with which e-cigarette markets are growing and changing
warrants greater surveillance of e-cigarette use. Such evidence would
provide a better sense of the balance between the public health risks
and benefits of e-cigarettes, which would be of great value for the
development of public health policy. Future research should also examine
the content of e-cigarettes in Canada to determine compliance with the
restriction on nicotine.
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Received: July 3, 2013 Accepted: January 18, 2014
Christine D. Czoli, BSc, David Hammond, PhD, Christine M. White,
MSc
Authors' Affiliation
School of Public Health and Health Systems, University of Waterloo,
Waterloo, ON
Correspondence: David Hammond, PhD, School of Public Health &
Health Systems, University of Waterloo, 200 University Avenue West,
Waterloo, ON N2L 3G1, Tel: 519-888-4567, ext.36462, E-mail:
dhammond@uwaterloo.ca
Sources of Funding: This research was supported by a grant from the
Canadian Cancer Society Research Institute, as well as the Canadian
Institutes of Health Research Training Grant in Population Intervention
for Chronic Disease Prevention: A PanCanadian Program (Grant #: 53893)
(Czoli), the Ontario Tobacco Research Unit Ashley Studentship for
Research in Tobacco Control (Czoli), the Ontario Graduate Scholarship
(Czoli), the Propel Centre for Population Health Impact, a Canadian
Institutes of Health Research New Investigator Award (Hammond), and a
Canadian Cancer Society Research Institute Junior Investigator Research
Award (Hammond).
Conflict of Interest: None to declare.
Table 1. Sample characteristics by smoking status
Characteristic Non-smokers Former smokers
n=708 n=74
% (n) % (n)
Age (years) Mean (SD) 22.5 (4.1) 26.2 (3.2)
16-19 28.7 (203) 4.0 (3)
20-24 38.3 (271) 23.0 (17)
25-30 33.0 (234) 73.0 (54)
Sex Male 49.6 (351) 37.8 (28)
Female 50.4 (357) 62.2 (46)
Ethnicity White 63.3 (448) 82.4 (61)
Non-White 36.7 (260) 17.6 (13)
Education Low 32.8 (232) 37.8 (28)
Moderate 40.2 (285) 41.9 (31)
High 27.0 (191) 20.3 (15)
Characteristic Current smokers Total
n=406 n=1188
% (n) % (n)
Age (years) Mean (SD) 24.6 (3.9) 23.5 (4.2)
16-19 14.5 (59) 22.4 (265)
20-24 31.0 (126) 34.8 (414)
25-30 54.5 (221) 42.8 (509)
Sex Male 33.7 (137) 43.4 (516)
Female 66.3 (269) 56.6 (672)
Ethnicity White 71.2 (289) 67.2 (798)
Non-White 28.8 (117) 32.8 (390)
Education Low 40.9 (166) 35.9 (426)
Moderate 34.0 (138) 38.2 (454)
High 25.1 (102) 25.9 (308)
* Education: Low = high school or less; Moderate = technical/trade
school, community college, or some university but no degree; High =
university degree or more.
Table 2. Prevalence of e-cigarette use by smoking status
Characteristic Prevalence (%)
Ever use of e-cigarettes
Non- Former Current Total
smokers smokers smokers
n=708 n=74 n=406 n=1188
All 5.2 18.9 34.5 16.1
Age (years) 16-19 5.9 -- * 33.9 12.5
20-24 5.5 -- 41.3 17.4
25-30 4.3 14.8 30.8 16.9
Sex Male 4.8 -- 33.6 13.2
Female 5.6 19.6 34.9 18.3
Ethnicity White 6.0 19.7 35.3 17.7
Non-White 3.8 -- 32.5 12.8
Education Low 6.5 -- 39.8 20.0
Moderate 5.6 19.4 37.7 16.3
High 3.1 -- 21.6 10.4
Characteristic Prevalence (%)
Current use of e-cigarettes
Non- Former Current Total
smokers smokers smokers
n=708 n=74 n=406 n=1188
All 0.8 1.4 15.0 5.7
Age (years) 16-19 0.5 -- 10.2 2.6
20-24 0.7 -- 20.6 7.0
25-30 1.3 0.0 13.1 6.3
Sex Male 0.9 -- 13.1 4.3
Female 0.8 0.0 16.0 6.8
Ethnicity White 0.7 1.6 17.0 6.6
Non-White 1.2 -- 10.3 3.8
Education Low 0.9 -- 13.9 5.9
Moderate 0.7 0.0 16.7 5.5
High 1.0 -- 14.7 5.8
* Data not reported due to small sample size (n<30).
Table 3. Factors associated with e-cigarette use
Characteristic Model 1:
Ever use of e-cigarettes *
OR (95% CI) ([dagger]) p-value
Age (years)
20-24 vs. 16-19 1.39 (0.83-2.32) 0.21
25-30 vs. 16-19 0.95 (0.57-1.59) 0.84
25-30 vs. 20-24 0.68 (0.46-1.00) 0.05
Sex
Female vs. male 1.02 (0.72-1.46) 0.90
Ethnicity
Non-White vs. White 0.82 (0.56-1.21) 0.31
Education
Moderate vs. low 0.89 (0.60-1.31) 0.54
High vs. low 0.49 (0.30-0.81) 0.005
High vs. moderate 0.56 (0.35-0.90) 0.02
Smoking status
Former smoker vs. non-smoker 4.25 (2.11-8.56) <0.001
Current smoker vs. non-smoker 9.84 (6.52-14.86) <0.001
Current smoker vs. former smoker 2.32 (1.24-4.35) 0.009
Characteristic Model 2:
Current use of e-cigarettes *
OR (95% CI) ([dagger]) p-value
Age (years)
20-24 vs. 16-19 1.71 (0.60-4.85) 0.31
25-30 vs. 16-19 1.18 (0.41-3.36) 0.76
25-30 vs. 20-24 0.69 (0.34-1.40) 0.30
Sex
Female vs. male 1.11 (0.55-2.24) 0.78
Ethnicity
Non-White vs. White 0.66 (0.31-1.43) 0.30
Education
Moderate vs. low 1.30 (0.63-2.69) 0.48
High vs. low 4.29 (1.60-11.50) 0.004
High vs. moderate 3.29 (1.26-8.62) 0.15
Smoking status
Former smoker vs. non-smoker 0.29 (0.03-2.84) 0.29
Current smoker vs. non-smoker 4.43 (1.64-11.94) 0.003
Current smoker vs. former smoker 15.15 (1.80-125.00) 0.012
* [R.sup.2] (Model 1) = 0.23; R2 (Model 2) = 0.15.
([dagger]) Odds ratios adjusted for all other variables in the table.
