Introduction

Over the last decade, the nicotine market has rapidly evolved with the emergence of e-cigarettes. More recently, a new generation of vapourised products has emerged which are often referred to as ‘heated’ tobacco sticks or ‘heated tobacco products’ (HTPs). Like e-cigarettes, these products use heat to volatilise nicotine below the point of combustion, so that consumers inhale an aerosol rather than smoke.1 Unlike e-cigarettes, which heat nicotine from a liquid solution, HTPs heat cigarette-like tobacco ‘sticks’. The constituents of the tobacco sticks that are heated and the type of heating device can vary across brands and product platforms.1 In essence, HTPs occupy a position in the nicotine spectrum between conventional ‘smoked’ cigarettes and e-cigarettes: their tobacco substrate resembles that of regular cigarettes, while their mechanism of delivering nicotine primarily through aerosol resembles that of e-cigarettes.

HTPs are marketed as reduced risk tobacco products,2 similar to previous generations of products such as Eclipse, Advance, Omni and Accord.3 4 The central principle underlying this marketing is that HTPs are likely to be less harmful than tobacco cigarettes because they do not combust tobacco, and therefore reduce exposure to the many harmful constituents of tobacco smoke.2 5 Most research conducted by tobacco manufacturers is consistent with this premise, showing that HTP aerosol contains lower levels of toxic emissions compared with cigarette smoke, and that use of HTPs is associated with reductions in biomarkers of exposure to several harmful and potentially harmful tobacco smoke constituents.6–8 However, independent examination of this evidence has revealed significant methodological issues with these findings,2 raising concerns regarding associations between HTP aerosol exposure and impaired vascular endothelial function,9 pulmonary effects10 and liver toxicity.11 Evidence from independent research examining HTPs is limited. A modelling analysis quantifying the harms of vapourised nicotine products relative to tobacco smoke distinguished these products along a spectrum spanning five orders of magnitude, with the greatest risks posed by tobacco cigarettes, followed sequentially by HTPs, e-cigarettes and nicotine inhalers.12 In an in vitro study using human bronchial epithelial cells, HTP aerosol resulted in significantly higher cytotoxicity than e-cigarette aerosol, but less than that of cigarette smoke.13 However, product testing of HTP aerosols have produced mixed findings regarding the levels of harmful and potentially harmful constituents in HTP aerosol relative to tobacco smoke.14–17 Further research is required to understand the potential health impacts of these novel products at the individual and population levels.

HTPs such as IQOS, Ploom and Glo are being sold in an increasing number of countries, and are marketed as premium products for tech-savvy users.18 Considerable market growth has been documented in Japan, where HTPs have been available since 2014.15 In a 2015 national survey of Japanese adults, 48% were aware of e-cigarettes and HTPs, with 7% reporting having ever used these products, and 1.3% reporting use in the last 30 days.19 A follow-up survey conducted 2 years later (2017) indicated that use of IQOS in the last 30 days had increased to 3.6%, while rates of use of other HTPs had remained low.20 Notably, the Japanese market is distinct in that nicotine-containing e-cigarettes are not permitted for sale,19 and the rise of HTPs has been accompanied by a decline in tobacco cigarette sales.21 To date, consumer uptake of HTPs has been limited in other markets. In Canada, Glo (British American Tobacco; BAT) and IQOS (Philip Morris International; PMI) are available in select cities and provinces.22 23 In Canada, HTPs are regulated as tobacco products,24 although they are not required to carry health warnings. In England, HTPs have been available since 2014,25 and are regulated as ‘other smoking tobacco and chewing tobacco’ products. Limited evidence suggests that consumer awareness and use of HTPs among adults is low.26

IQOS, Glo and other modern HTPs are not available for sale in the USA without the Food and Drug Administration’s (FDA) approval as a new tobacco product. In May 2017, PMI submitted an application to permit the sale of IQOS in the USA, along with a modified-risk tobacco product (MRTP) application for its IQOS system and three types of its ‘HeatStick’ products (https://www.fda.gov/tobaccoproducts/labeling/marketingandadvertising/ucm546281.htm). In January 2018, the US FDA Tobacco Products Scientific Advisory Committee (TPSAC) reviewed the evidence submitted by PMI and concluded that, although the product reduces exposure to harmful constituents found in tobacco,26 PMI had not provided adequate evidence to demonstrate that such reduced exposure would likely translate into measurable reductions in tobacco-related diseases.27 As part of the decision, the Committee expressed a range of opinions regarding the likelihood that youth never-smokers would become established users of the IQOS system, and noted the absence of data among youth.27 Indeed, virtually all of the existing evidence on use of HTPs has focused on adults and established tobacco users. Although surveys of Japanese consumers indicate greater rates of use among younger individuals,20 to our knowledge, there is little or no data on use or perceptions among youth, including youth smokers and non-smokers. While TPSAC recommended denial of the MRTP application, the final FDA decision is pending.

The current study sought to fill this gap by examining awareness and interest in IQOS among youth in Canada, England and the USA. The study also compared susceptibility to IQOS with susceptibility to e-cigarettes and conventional cigarettes, and examined differences among sub-groups.

Methods

Measures

Respondents were shown an image of the IQOS product (see figure 1) and asked several questions. Respondents were asked about their awareness of the product, with the question: ‘Have you heard of a product called IQOS, which heats a stick of tobacco instead of burning it?’, with response options ‘yes’ or ‘no’. Next, respondents were asked about their interest in trying the product, with the question: ‘Would you be interested in trying this product?’, with response options ‘definitely not’, ‘probably not’, ‘probably yes’ and ‘definitely yes’. Respondents were also asked a measure of susceptibility established for tobacco cigarettes (‘If one of your best friends were to offer you a cigarette, would you smoke it?’) which was adapted for IQOS (‘If one of your best friends were to offer you this product, would you try it?’) and for e-cigarettes (‘If one of your best friends were to offer you an e-cigarette/vaping device, would you use it?’), and included the response options ‘definitely not’, ‘probably not’, ‘probably yes’ and ‘definitely yes’. Respondents could also select the response options ‘don’t know’ or ‘refuse to answer’ for all questions.

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Figure 1

IQOS heated tobacco product device and tobacco sticks.

Smoking status was defined using the following categories: never smokers had never smoked a cigarette; experimental smokers had smoked less than 100 cigarettes in their lifetime; former smokers had smoked 100 cigarettes in their lifetime, but did not report smoking in the past 30 days; and current smokers had smoked 100 cigarettes in their lifetime and reported smoking in the past 30 days. Vaping status was defined using parallel categories, including the requirement for former vapers and current vapers to have vaped on 100 days in their lifetime.

Results

After excluding those who failed the data quality check (n=382) and those missing any of the variables used in the weighting (n=1022), 12 064 respondents comprised the analytic sample. Characteristics of the sample, unweighted and weighted, are shown in table 1.

Key binary outcomes are presented by country and smoking status in table 2 (for the presentation of outcomes with the full range of responses, see online supplementary table 1). Youth in the USA reported the greatest levels of awareness of IQOS (χ² _{(df=2, n=11 770)}=41.3, p<0.001), while Canadian youth reported the least interest and susceptibility to trying IQOS (χ² _{(df=2, n=11 416)}=75.8, p<0.001) and (χ² _{(df=2, n=11 499)}=98.4, p<0.001), respectively. As shown in table 2, key outcomes varied by smoking status within each country: although awareness, interest and susceptibility to trying IQOS were reported by a greater proportion of youth who were currently smoking or had a history of smoking, considerable proportions of never smokers in each country also reported being interested in and susceptible to trying this novel product.

Among youth never smokers and never vapers across all countries, susceptibility to trying IQOS (25.1%) was higher than for tobacco cigarettes (19.3%), but lower than for e-cigarettes (29.1%). This pattern across products was also reflected within each country (see figure 2).

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Figure 2

Susceptibility to trying conventional cigarettes, IQOS and e-cigarettes among never-smoking and never-vaping youth, by country (N=7012) Analyses conducted using weighted data. Respondents with missing data are not included in weighted estimates

Table 3 presents results of separate multivariate logistic regression analyses for IQOS awareness, interest in trying and susceptibility to trying among youth, across countries. Compared with Canada, youth in the USA were significantly more likely to be aware of IQOS, and significantly less susceptible to trying the product; in contrast, youth in England were significantly less likely to be aware of IQOS, and significantly more susceptible to trying the product.

Across all countries, males were significantly more likely to report IQOS awareness, interest in trying and susceptibility to trying. Several differences in youth interest in trying IQOS were noted by country and sex: interest in trying the product was more likely to be reported by females in England compared with those in Canada (aOR=1.36 (95% CI 1.08 to 1.70), p=0.008), and by males in the USA compared with England (aOR=1.35 (95% CI 1.08 to 1.69), p=0.009). With respect to age, awareness of IQOS decreased significantly with increasing age in Canada and England, while in the USA, older youth were significantly more likely to report awareness of the product (vs Canada: aOR=1.25 (95% CI 1.06 to 1.48), p=0.008; vs England: aOR=1.23 (95% CI 1.03 to 1.46), p=0.021). Similarly, older youth in the USA were more likely to report interest in trying IQOS compared with those in Canada and England (aOR=1.12 (95% CI 1.01 to 1.25), p=0.032, and aOR=1.17 (95% CI 1.05 to 1.30), p=0.005, respectively). Susceptibility to trying IQOS decreased significantly with increasing age among youth in all countries.

Smoking status was significantly associated with all IQOS outcomes. Overall, compared with never smokers, experimental smokers and former smokers were significantly more likely to be aware of the product. Trends differed by country, with current smokers in the USA significantly more likely to be aware of IQOS than those in Canada and England (aOR=2.10 (95% CI 1.14 to 3.86), p=0.018, and aOR=2.75 (95% CI 1.46 to 5.17), p=0.002, respectively). In addition, experimental smokers in Canada were significantly more likely to report awareness of IQOS than those in England (aOR=1.92 (95% CI 1.11 to 3.33), p=0.019). Across all countries, experimental smokers, former smokers and current smokers were all significantly more likely to report interest in trying IQOS and susceptibility to trying IQOS. However, former smokers in Canada were significantly less likely than those in England and the USA to report interest in trying IQOS (aOR=0.28 (95% CI 0.12 to 0.65), p=0.003, and aOR=0.31 (95% CI 0.12 to 0.80), p=0.016), respectively). Compared with Canada, current smokers in the USA were significantly more likely to report being interested in trying IQOS (aOR=2.18 (95% CI 1.08 to 4.40), p=0.031). Susceptibility to trying IQOS also differed by country and smoking status, with former smokers in Canada significantly less susceptible to trying IQOS compared with those in England and the USA (aOR=0.20 (95% CI 0.08 to 0.51), p=0.001, and aOR=0.33 (95% CI 0.13 to 0.83), p=0.019, respectively).

With respect to use of e-cigarettes, compared with never vapers, experimental vapers, former vapers and current vapers were all significantly more likely to be aware of, interested in trying and susceptible to trying IQOS across all countries. In addition, former vapers in Canada were significantly more likely than those in the USA to report awareness of IQOS (aOR=6.68 (95% CI 1.55 to 28.86), p=0.011), as were current vapers in England compared with those in the USA (aOR=4.02 (95% CI 1.66 to 9.77), p=0.002).

Discussion

The study findings indicate that awareness of IQOS among youth is emerging in Canada, England and the USA. In particular, levels of awareness were higher among males, and among youth who used tobacco cigarettes or e-cigarettes. Both Canada and England have comprehensive restrictions on advertising and promotion of tobacco products which have likely had an impact on the industry’s ability to promote awareness of these products. Indeed, PMI has been promoting IQOS on packages of conventional cigarettes as one of the only marketing channels available.31 In addition, the Canadian market has largely been restricted to several large urban cities which may impact consumer awareness of IQOS.22 23

Interest and susceptibility to trying IQOS among youth were also associated with male sex, use of tobacco cigarettes and use of e-cigarettes. However, the magnitude of associations between tobacco use and IQOS outcomes was markedly greater than those for e-cigarette use, underscoring the predominance and consistency of cigarette smoking as a factor associated with use of other tobacco products.32 Nevertheless, some youth with no history of tobacco or e-cigarette use also expressed interest and susceptibility to trying IQOS: in all countries, approximately one-fifth of never-users expressed interest in trying IQOS, while approximately one-third were considered susceptible to trying the product. Although it is unclear whether and how IQOS may affect rates of smoking, these results raise concerns as to the broad appeal of these products among youth, particularly among those with no past use of tobacco or nicotine products.

Across and within all countries, susceptibility to trying IQOS was greater than for tobacco cigarettes, but lower than for e-cigarettes. An FDA review of consumer studies submitted by PMI concluded that some youth non-smokers would be expected to experiment with IQOS, but speculated that interest may be lower than for e-cigarettes due to predominantly ‘negative’ associations with tobacco among young non-smokers.6 The current findings appear to be consistent with this suggestion. More generally, the findings reflect the evolving tobacco/nicotine market, in which novel and alternative products are playing an increasingly important role.32 Understanding youth susceptibility and perceptions of these various products may help inform youth substance use prevention. Qualitative evidence suggests that IQOS packaging and marketing may have particular appeal among youth and young adults, given the important role that technology plays in their lives.33 Future research examining whether youth view HTPs as appealing or harmful relative to tobacco cigarettes and other products is critically important to understand the potential role of these products in the rapidly evolving market. It is also worth noting that the current study tested interest and susceptibility for an ‘unflavoured’ version of the HTP tobacco sticks. However, the MRTP applications to the US FDA and tobacco sticks on the market in different countries include varieties with menthol flavours (eg, Marlboro Smooth Menthol and Marlboro Fresh Menthol) which are associated with greater appeal among youth and young adults.34 35 Therefore, actual levels of interest and susceptibility among youth may be higher than estimates from the current study.

Although some differences in levels of awareness, interest in trying and susceptibility to trying IQOS were found between countries, these differences were not consistent, likely reflecting the novelty of HTPs. Continued monitoring of awareness, interest in trying and prevalence of use of HTPs is needed to better understand the potential public health impact of these products, particularly across jurisdictions with differing policies for various tobacco/nicotine products as well as differing cultural values which appear to play a role in how these products are perceived.33 Robust and independent research will be particularly important, given PMI’s pledge to develop and market reduced-risk alternatives to cigarette smoking.36