E-cigarette use among US adolescents: Perceptions of relative addiction and harm

Abstract

Objective:

Between 2013 and 2014, past 30-day use of e-cigarettes increased from 4.5% to 13.4% among US high school students aged 9–19 years. We sought to examine the influence of perceived addiction and harm of e-cigarettes on e-cigarette use among adolescents.

Design:

Self-reported use and perception of harm of e-cigarettes were assessed using a cross-sectional design.

Setting:

Data were collected from the 2014 National Youth Tobacco Survey.

Method:

Multivariate logistic regression models were employed regressing lifetime e-cigarette use and past 30-day use on established covariate factors.

Results:

Perceiving e-cigarettes as less harmful than conventional cigarettes increased students’ odds of lifetime use (odds ratio [OR] = 2.40, 95% confidence interval [CI] = 1.98–2.90) and past 30-day use (OR = 2.18, 95% CI = 1.63–2.92) of e-cigarettes. Perceiving e-cigarettes as less addictive than conventional cigarettes also increased students’ odds of lifetime use (OR = 2.11, 95% CI = 1.82–2.45) and past 30-day use (OR = 1.93, 95% CI = 1.57–2.38) of e-cigarettes; however, perceiving e-cigarettes as more addictive than conventional cigarettes also increased students’ odds of lifetime use (OR = 1.85, 95% CI = 1.37–2.49) and past 30-day use (OR = 2.68, 95% CI = 1.84–3.90) of e-cigarettes. Other influencing factors of e-cigarette use among youth included race, grade level, living with a smoker and lifetime use of regular cigarettes.

Conclusion:

The perception that e-cigarettes are less addictive and harmful than their conventional counterparts may be an important risk factor for the use of e-cigarettes. Factors influencing young people’s perceptions need to be examined further.

Keywords

E-cigarettes perceived harm USA young people

Introduction

In the USA, electronic cigarettes (e-cigarettes) have recently gained popularity, and claims have been made that they are a safer alternative to conventional cigarettes and a potential cessation device to reduce tobacco smoking (Etter and Bullen, 2014). Although e-cigarettes have not been evaluated thoroughly by the US Food and Drug Administration (FDA), preliminary studies suggest that e-cigarettes release fewer toxins than regular cigarettes (Goniewicz et al., 2014). Although many remain hopeful that e-cigarettes will reduce mortality and morbidity among current smokers, they have not been proven to be completely ‘safe’ or ‘harm free’. This is especially concerning due to the recent increase in e-cigarette use among youth and its potential for addiction and harm (Benowitz, 2014; Camenga et al., 2014). Moreover, young people who use e-cigarettes as their first tobacco product have been found to be more likely than those who have not tried e-cigarettes to use conventional cigarettes (Leventhal et al., 2015; Primack et al., 2015; Wills et al., 2016), supporting those who have postulated e-cigarettes as a gateway to other tobacco products (Giroud et al., 2015; Schneider and Diehl, 2016; Wasowicz et al., 2015;Wills et al., 2015).

While research regarding the potential health impact of e-cigarettes is in its infancy, e-cigarettes have been found to contain substances such as formaldehyde (Cooke et al., 2015), and a recent study (Allen et al., 2016) found e-cigarettes to contain a flavouring chemical, diacetyl, which has been known to cause bronchiolitis obliterans (commonly known as ‘Popcorn Lung’). Additionally, nicotine exposure during adolescence has been linked to impaired brain development, affecting the hippocampus and cerebral cortex (Counotte et al., 2012; Dwyer et al., 2008; England et al., 2015; Smith et al., 2015). Without the regulation of these products, controlled nicotine levels and other harmful substances is of concern (Varlet et al., 2015; Wasowicz et al., 2015). Finally, health risks associated with long-term exposure to e-cigarettes among persons who use it as their primary nicotine delivery product are unknown.

Current e-cigarette use (past 30-day use) among the US high school students increased from 0.6% in 2010 to 16.0% in 2015, with more than 2 million students currently using the product (Corey et al., 2013; Singh et al., 2016; US Department of Health and Human Services [USDHHS], 2015b). In 2014, e-cigarette use became more common for high school students than hookah (9.4%), cigarettes (9.2%) and smokeless tobacco (5.5%) (USDHHS, 2015b). Young people who report experimenting with e-cigarettes tend to be older (Pepper et al., 2013), White (Camenga et al., 2014; Cho et al., 2011), men (Cho et al., 2011), of lower socioeconomic status (Pepper et al., 2013) and dual users of e-cigarettes and conventional cigarettes (Saddleson et al., 2015).

Perception of harm of all tobacco products has been proposed to serve as a protective factor against tobacco use (Agaku et al., 2013); research suggests that the majority of adults believe e-cigarettes are less harmful and less addictive than conventional cigarettes (Pearson et al., 2012), and these beliefs may be associated with e-cigarettes experimentation (Choi and Forster, 2014). A recent study, using the 2012 National Youth Tobacco Survey (NYTS), found that 71.8% of young people trying e-cigarettes believed them to be less harmful than conventional cigarettes (Amrock et al., 2015). While the literature has examined the relative risk of e-cigarettes compared to conventional cigarettes, there remains a gap in the literature regarding youth relative risk of addictiveness and harm of e-cigarettes and how this perception relates to young people’s use of the product. Berg et al. (2015) have examined the favourability of e-cigarettes as it pertained to perceived harm and addiction among college students. They found that college students perceived e-cigarettes to be less harmful than hookah, cigarettes, cigars and smokeless tobacco; however, they found no significant associations between perceived addictiveness and social acceptance of the products. With evidence that young people may perceive e-cigarettes to be less harmful and addictive than conventional cigarettes, we sought to examine if the relative risk of addiction and harm of e-cigarettes was associated with use among young people aged 9–19 years.

Methods

Participants and procedures

Data were obtained from the 2014 NYTS. The NYTS provides a nationally representative sample of middle and high school students in the USA and is designed to provide national estimates of tobacco-related attitudes, beliefs and behaviours. The NYTS employs a randomised, multistage cluster sample design. A sample of 22,007 students participated in the cross-sectional survey. A weighting factor was applied to each student record to adjust for non-response and variance in selection probabilities and to provide nationally representative estimates. After accounting for weighting factors, our sample for the current study was 27,294 students ages 9 to 19. The weighting factor was included in all analyses to account for the complex sample design. Goodness of fit of the logistic model was assessed using methods proposed by Archer and Lemeshow (2006), which accounts for sampling weights and cluster design of the survey data. Data were analysed using STATA MP 13.1. Complete information concerning the NYTS has been detailed elsewhere (USDHHS, 2015a).

Measures and analysis

We employed two multivariate logistic regression models and calculated odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) to examine factors associated with respondents ever using an e-cigarette during their lifetime (model 1) and past 30-day e-cigarette use (model 2). Items were measured using the respondents’ answers to the questions: ‘Have you ever tried an electronic cigarette or e-cigarette such as Blu, 21st Century Smoke or NJOY?’ and ‘During the past 30 days, on how many days did you use electronic cigarettes or e-cigarettes such as Blu, 21st Century Smoke, or NJOY?’ Responses were dichotomised into ‘yes’ and ‘no’. Multiple covariates were included in the models to test for their association with the dependent measures. Perceived harm of e-cigarettes was assessed by asking ‘Do you believe that e-cigarettes are (“less harmful,” “equally harmful” or “more harmful”) than regular cigarettes?’ Perceived addictiveness of e-cigarettes was assessed by asking ‘Do you believe that e-cigarettes are (“less addictive,” “equally addictive” or “more addictive”) than cigarettes?’ Participants who indicated that they had ‘never heard of electronic cigarettes or e-cigarettes’ or did not ‘know enough about these products’ were not included in the analysis. Smoking history was measured by asking ‘About how many cigarettes have you smoked in your entire life?’ Those responding ‘never smoked’ were considered non-smokers, while lifetime smoking categories included smoked ‘1–15 cigarettes’ and smoked ‘16 or more cigarettes’. Conceptually, we chose these cut-offs because we felt that 1–15 cigarettes in a lifetime of youth is reflective of an experimenter, whereas a young person who smoked 16 or more cigarettes in their lifetime is reflective of a current or former users. Operationally, we chose these values because looking at the data spread of these variables, 1–15 and 16+ were natural cut points based on the frequencies. Other covariates measured included living with smoker, race/ethnicity, grade level and sex.

Results

In 2014, 5,295 (19.4%) of all the US middle school and high school students (aged 9–19) reported trying an e-cigarette during their lifetime, and 2,499 (9.2%) reported current use of e-cigarettes, defined as past 30-day use. Totally, 48% of these students felt that e-cigarettes were less harmful than traditional cigarettes, and 29% felt that e-cigarettes were less addictive than traditional cigarettes (see Table 1).

Table 1.

Electronic cigarette use and related characteristics among US students aged 9–19, National Youth Tobacco Survey, 2014 (N = 27,294).

Variable	N ^a	%^a
Sex
Female	13,607	49.9
Male	13,476	48.4
Race/ethnicity
NH White	13,756	50.4
NH Black	3,778	13.8
Hispanic	5,652	20.7
Other	2,657	9.7
Age (years)
9–14	11,311	43.1
15–19	11,564	45.7
Live with a regular cigarette smoker
No	19,422	71.2
Yes	7,873	28.8
Willingness to try e-cigarette if offered by friend
No	21,346	78.2
Yes	5,652	20.7
Lifetime use, e-cigarettes
No	21,441	78.6
Yes	5,295	19.4
Past 30-day use, e-cigarettes
Yes	24,367	89.3
No	2,499	9.2
Lifetime use, regular cigarettes
Non-smoker	21,103	77.3
1–15 cigarettes	4,259	15.6
16+ cigarettes	1,589	5.8
Perceived harm of e-cigarettes compared to regular cigarettes
Equally harmful	3,975	14.6
Less harmful	13,243	48.5
More harmful	917	3.4
Do not know	6,998	25.6
Addictive belief of e-cigarettes compared to regular cigarettes
Equally addictive	7,742	28.4
Less addictive	8,132	29.8
More addictive	1,405	5.2
Do not know	7,884	28.9

NH: non-Hispanic.

Frequencies and percentages may not add up to total N due to missing data.

Lifetime e-cigarette use

Results of multivariate logistic regression analyses determined that, independent of covariates included in the model, perceived less harm (OR = 2.40, 95% CI = 1.98–2.90) and perceived less addictiveness of e-cigarettes (OR = 2.11; 95% CI = 1.82–2.45) were significantly associated with lifetime use of e-cigarettes. Those who perceived the addictiveness of e-cigarettes to be more so than conventional cigarettes also indicated higher odds of having tried e-cigarettes in their lifetime (OR = 1.85; 95% CI = 1.37–2.49). The strongest predictor of ever trying an e-cigarette was smoking history. Those who had smoked 1–15 conventional cigarettes in their lifetime had more than seven times the odds of having tried an e-cigarette than never smokers, and those who had smoked 16 or more conventional cigarettes had nearly 27 times the odds of having tried an e-cigarette than never smokers. Those living with a smoker (OR = 1.44; 95% CI = 1.24–1.68) and who were older (OR = 1.85; 95% CI = 1.47–2.33) were significantly more likely to have used an e-cigarette in their lifetime. Non-Hispanic Black youth were significantly less likely than White students (OR = 0.68; 95% CI = 0.50–0.93) to have used e-cigarettes in their lifetime, while Hispanic youth were significantly more likely (OR = 1.33; 95% CI = 1.05–1.67) to have used e-cigarettes in their lifetime. There was no significant relationship between sex and lifetime use of e-cigarettes (see Table 2).

Table 2.

Multivariate logistic regression analyses examining the factors associated with past 30-day and lifetime use of e-cigarettes, among US students aged 9–19, National Youth Tobacco Survey, 2014.

Variable	Lifetime use	Past 30-day use
Variable	OR (95% CI)	OR (95% CI)
Sex
Female	1.00	1.00
Male	1.03 (0.92–1.15)	0.99 (0.86–1.13)
Race/ethnicity
NH White	1.00	1.00
NH Black	0.68 (0.50–0.93)	0.53 (0.36–0.76)
Hispanic	1.33 (1.05–1.67)	1.21 (0.88–1.66)
Other	0.93 (0.75–1.16)	0.81 (0.59–1.11)
Age (years)
9–14	1.00	1.00
15–19	1.85 (1.47–2.33)	1.82 (1.39–2.38)
Live with a regular cigarette smoker
No	1.00	1.00
Yes	1.44 (1.24–1.68)	1.12 (0.92–1.37)
Lifetime use, regular cigarettes
Never smoked	1.00	1.00
1–15 cigarettes	7.84 (6.57–9.37)	6.02 (4.86–7.45)
16+ cigarettes	27.03 (20.30–35.99)	15.41 (11.88–19.99)
Perceived harm e-cigarettes compared to regular cigarettes^a
Equally harmful	1.00	1.00
Less harmful	2.40 (1.98–2.90)	2.18 (1.63–2.92)
More harmful	0.73 (0.46–1.18)	0.63 (0.33–1.23)
Addictive belief of e-cigarettes compared to regular cigarettes^a
Equally addictive	1.00	1.00
Less addictive	2.11 (1.82–2.45)	1.93 (1.57–2.38)
More addictive	1.85 (1.37–2.49)	2.68 (1.84–3.90)

NH: non-Hispanic.

Respondents who indicated ‘I don’t know enough about these products’ were excluded from the analyses.

Bold values indicate significance.

Past 30-day e-cigarette use

Those who perceived less harm and perceived less addictiveness of e-cigarettes, when compared with conventional cigarettes, had increased odds of past 30-day use as well. Findings indicated that perceived less harm (OR = 2.18, 95% CI = 1.63–2.92) and perceived less addictiveness of e-cigarettes (OR = 1.93; 95% CI = 1.57–2.38) were significantly associated with past 30-day use of e-cigarettes. In accordance with findings of lifetime use, those who perceived the addictiveness of e-cigarettes to be more so than conventional cigarettes also indicated higher odds of having used e-cigarettes in the past 30 days (OR = 2.68; 95% CI = 1.84–3.90). Smoking history was the strongest predictor of past 30-day e-cigarette use. Those who had smoked 1–15 conventional cigarettes in the past 30 days were six times more likely to have used e-cigarettes during the past 30 days than never smokers, and those who had smoked 16 or more conventional cigarettes in their lifetime were 15 times more likely to have used e-cigarettes during the past 30 days than never smokers. Non-Hispanic Black youth were significantly less likely to use e-cigarettes in the past 30 days (OR = 0.52; 95% CI = 0.36–0.76) than non-Hispanic White youth. Older youth (aged 15–19) were significantly more likely than younger youth (aged 9–14) to have used e-cigarettes in the past 30 days (OR = 1.82; 95% CI = 1.39–2.38). There was no significant relationship between 30-day use of e-cigarettes and sex or living with a smoker (see Table 2).

Discussion

We found that youth perceptions that e-cigarettes are less harmful than convention cigarettes were associated with increased odds of e-cigarette use. This complements findings from previous research (Agaku et al., 2013; Amrock et al., 2015). Although not explored in this study, one factor influencing young people’s use of e-cigarettes could be the marketing messages targeted at young adults that portray e-cigarettes as less harmful than conventional cigarettes (Paek et al., 2014); however, more research is needed to confirm this assumption. Such messages may help explain our finding that 48.5% of youth aged between 9 and 19 years, living in the USA, now believe e-cigarettes are less harmful than conventional cigarettes, up from 29.3% in 2012 (Corey et al., 2013).

We also found that young people who perceived e-cigarettes to be more addictive and less addictive than conventional cigarettes were more likely to use e-cigarettes. There is no definitive explanation for this finding; however, it does indicate a need for further research to better understand young people’s perception of addiction and the influence it has on their e-cigarette use.

Although previous literature has focused on gender differences related to tobacco use (Pepper et al., 2013), we did not find a significant association between sex and e-cigarette use. Previous literature has also associated maternal smoking behaviour with e-cigarette use among young people aged 9–19 years (Hampson et al., 2015). Findings from this study suggest that lifetime e-cigarette use, but not past 30-day use, was associated with living with a smoker. Consistent with previous studies (Saddleson et al., 2015), the strongest predictor of e-cigarette use was conventional cigarette use. While initial studies have begun to explore young people’s reasons for experimenting with e-cigarettes (Kong et al., 2014), nationally representative surveys are limited with few items that measure the reasons for trying e-cigarettes. The inclusion of such items would allow for better explanations concerning young people’s behaviour, especially regarding reasons for using e-cigarettes.

Findings of this study are subject to limitations. Data are self-reported and are subject to information biases. Due to the cross-sectional nature of the data, causal conclusions cannot be made regarding outcomes. Also, due item from the survey that determined use, ‘During the past 30-days, on how many days did you use electronic cigarettes or e-cigarettes such as Blu, 21st Century Smoke, or NJOY?’, does not include pen-style e-cigarettes, eGos, or Mods. Such limitation may result students underreporting use. Additionally, the survey did not ask about absolute harm but rather harmfulness comparative to conventional cigarettes. Without a baseline of students’ perceived absolute harm of either conventional cigarettes or e-cigarettes, this harm may be misconceived. Data are also limited to young people who are enrolled in school, not representing those not in school, some of whom may be at higher risk of tobacco use. Finally, while we accounted for many covariates in our analyses, there could be covariates for e-cigarette use unaccounted for in the NYTS survey.

Perception of harm and addiction has been noted to influence behaviour choices, as seen in elicited reasons for discontinuation of e-cigarette use among youth and young adults (Kong et al., 2015). The perception that e-cigarettes are less addictive and less harmful than their combustible counterparts may be an important risk factor for the use of e-cigarettes; however, behaviour may also be driving this perception of harm. Ongoing surveillance of trends in e-cigarette use and relative risk perceptions are needed to better understand the factors that may promote initiation among youth. Additional research is needed to examine the interrelationship of e-cigarette use, conventional cigarette use, addiction potential and potential health effects associated with these products.

Footnotes

Funding

The author(s) received no financial support for the research, authorship and/or publication of this article.

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