Identifying factors that conjointly influence nicotine vaping product relative harm perception among smokers and recent ex-smokers: Findings from the 2016 ITC Four Country Smoking and Vaping Survey
Introduction
The nicotine market landscape is rapidly changing with the emergence of new nicotine products such as nicotine vaping products (NVPs, also known as e-cigarettes) in recent years. However, not all nicotine-containing products are equally harmful (Hatsukami et al., 2007; Zeller et al., 2009). The risk profile of different nicotine-containing products is on a continuum, with the most harmful products at one end being combustible tobacco products to the least harmful ones on the other end being nicotine replacement therapy/products (NRTs), with vaping products/e-cigarettes somewhere between the two extremes (Czoli et al., 2017; Hatsukami et al., 2007). The extent of risk of these various products is dependent on the mode of nicotine delivery and product constituents. Smoked products like conventional cigarettes are the most harmful because of the many highly toxic constituents present in smoke and the highly efficient delivery of nicotine to the users via the lung. NRTs, which sit on the other end of the risk spectrum, are the least harmful because of presence of few toxic by-products and their clinical safety (Zeller et al., 2009). NVPs, on the other hand, deliver nicotine via an aerosol without any combustion and they may contain additives and flavours, which make them substantially less harmful than smoked products but likely to be more harmful than NRTs (Zeller et al., 2009). Nevertheless, the long-term health effects of NVPs remain unknown.
Despite evidence to date demonstrating the continuum of risk for nicotine-containing products, a substantial number of smokers misperceive NVPs as equally or more harmful than conventional cigarettes (Yong et al., 2017) and the proportion has increased over time (Brose et al., 2015; Huang et al., 2019). This over concern may be discouraging switching to NVP use among current smokers when it would be appropriate (Huang et al., 2019). With the ongoing controversies surrounding the risks and benefits of NVP use, the risk of NVPs is often overestimated. One possible reason for misperceiving NVPs as equally harmful as, or even more harmful than, conventional cigarettes is the mistaken belief commonly held by smokers that nicotine is the most harmful constituent of tobacco (Bansal et al., 2004; Cummings et al., 2004; Wilson et al., 2019). This misbelief is likely to increase even more with the recent spate of lung disease associated with vaping among young people in the US (Krishnasamy et al., 2020) although tetrahyrocannabinol (THC) oil and its additive (i.e., vitamin E acetate) rather than nicotine is likely the main cause of this lung disease (Boudi et al., 2019). Past research has shown that misbelief about nicotine harmfulness is a strong predictor of misperception of NRT product harmfulness relative to smoking (Wilson et al., 2019). However, the relationship between the harm perception of NVPs and that of NRT products relative to smoking is unclear to date and warrants further studies to determine if misperception of harmfulness of one nicotine product influences the other.
Research has also shown that misperception of the relative harmfulness of NVPs is much higher in countries with a more restrictive policy on NVPs as compared to countries with a less restrictive policy suggesting that NVP risk perceptions are likely also influenced by the policy environment for NVPs (Yong et al., 2017). The risk profile of NVPs is more likely to be greatly overestimated in a more restrictive policy environment than in a less restrictive environment since a highly restricted/regulated product tends to be perceived as dangerous (Wilson et al., 2019; Yong et al., 2017).
One major consequence of misperceptions of the relative harmfulness of NVPs is that they are preventing smokers from using them as smoking cessation aids or long-term substitutes for smoking (Bansal et al., 2004). Thus, it is critical that misperceptions about the relative risk of NVPs are addressed to ensure that smokers can make informed choices about alternative forms of nicotine delivery, particularly for those who are unable or unwilling to quit smoking (Huang et al., 2019; Wilson et al., 2019).
To date, studies, including ours, focusing on predictors of people’s misperceptions of nicotine containing products are largely conducted using a regression-based approach (e.g., Bansal et al. (2004); Yong et al. (2017); Tan et al., 2014). This method typically assumes a linear relationship between predictors and outcome. Any attempts to explore interactions between predictors typically do not go beyond a two-way interaction because of the difficulty in interpreting higher-order interactions and reduced power to detect interactive effects due to small sample size. An alternative strategy such as decision tree method can overcome these shortcomings. Decision tree methods have been successfully applied in public health (Camp and Slattery, 2002; Lemon et al., 2003) and health behaviour research (Fuller-Tyszkiewicz et al., 2016; Lemon et al., 2003), including smoking research (Piper et al., 2011; Swan et al., 2004) but often underutilized because of lack of awareness of their utility and statistical properties (Lemon et al., 2003). The objective of this study was to develop a robust decision tree model of the conditions under which smokers and recent ex-smokers are more or less likely to be misinformed about the harmfulness of NVPs relative to smoking. Such a model can then be used to inform the development of bespoke corrective intervention for different subgroups so that they can make informed choices about alternative nicotine delivery products to help quit smoking successfully.
This study aimed to use decision-tree models to help (a) identify key factors that conjointly influenced the harmfulness perception of vaping relative to smoking among smokers and recent ex-smokers; and (b) determine whether they differed by country, a proxy for NVP policy environment. The study is descriptive and exploratory since decision-tree analysis is inherently a data-driven approach useful for generating rather than testing specific hypotheses (Lemon et al., 2003).
Section snippets
Sample and design
Data (n = 11,838) come from the 2016 ITC 4 Country Smoking and Vaping (4CV) Survey conducted in Australia (n = 1490), Canada (n = 3576), England (n = 4220), and the US (n = 2552). Our sample consisted of current smokers (smoking at least monthly) and ex-smokers (quit less than 2 years), regardless of any current vaping. Sample characteristics are presented in Table 1.
Study questionnaires and materials were reviewed and provided clearance by Research Ethics Committees at the following
Factors conjointly influencing vaping harm perception
Fig. 2 (A–D) presents the results from the decision tree analysis (DTA) in each country. DTA identified nicotine replacement therapy (NRT) harmfulness perceptions relative to smoking, perceived vaping portrayal in the media and other sources as positive, negative or balanced, recency of seeking internet vaping information, knowledge of smoking harms, past month exposure to vaping news stories, past month exposure to vaping products advertising, age, ethnicity and education as the key variables
Main findings
The DTA results indicated that NRT relative harmfulness perceptions and perceived portrayal of NVPs from all media sources are two key factors common across all four high-income countries that conjointly influenced how smokers and recent ex-smokers perceived the harmfulness of NVPs relative to smoking. However, there was also evidence of country variations in factors that interacted with each other to influence relative risk perception of NVPs which included socio-demographic variables such as
Role of funding source
This study was supported by grants from the US National Cancer Institute (P01 CA200512), the Canadian Institutes of Health Research (FDN-148477), and by the National Health and Medical Research Council of Australia (APP1106451). This study was also supported by a US NCI P01 Pilot study grant to HHY. GTF was supported by a Senior Investigator Grant from the Ontario Institute for Cancer Research (IA-004).
Contributors
H.H.Y., C.K., and R.B. contributed to the study’s concept and design. M.A.M. conducted the statistical analysis. H.H.Y. wrote the first draft of the manuscript and all authors contributed to revisions and have approved the final manuscript.
Declaration of Competing Interest
K.M.C. has served as paid expert witness in litigation filed against cigarette manufacturers. G.T.F. has served as expert witnesses on behalf of governments in litigation involving the tobacco "industry. All other authors have no conflicts of interest to declare.
Acknowledgments
The authors would like to acknowledge and thank all those that contributed to the International Tobacco Control Four Country Smoking and Vaping (ITC 4CV) Survey: all study investigators and collaborators, and the project staff at their respective institutions.
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2022, Addictive BehaviorsCitation Excerpt :It is notable however, that that the majority of daily smokers in our study did not initiate NVP use, or initiated use, but stopped using them. There could be several reasons for this, including that they do not want to give up cigarette smoking (McKeganey & Dickson, 2017), worry about the risks of vaping and/or about the unknown risks of long-term use (Marques et al., 2021), misperceptions about the relative harmfulness of NVPs compared to cigarettes (Elton-Marshall et al., 2020; National Cancer Institute (NCI), 2020; Wilson et al., 2019; Yong et al., 2021), they have not been advised to do so by a healthcare provider (Gravely et al., 2019; Singh et al., 2017; Van Gucht and Baeyens, 2016; University of North Carolina Health Care System, 2016), they believe that NVPs are unreliable and/or too complex (McKeganey & Dickson, 2017), dissatisfaction with vaping or NVPs were not found to be an effective substitute for cigarettes (Yong et al., 2019), restrictive regulatory policies (e.g., they are not legal to be sold and therefore there are accessibility barriers) (Lum et al., 2021; Morphett et al., 2019; Yong et al., 2017), and/or warnings from public health organizations not to vape as they have not been found to be safe and effective in helping smokers quit (American Lung Association, 2020; Gee et al., 2021; Joint Position Statement from Six Lung Societies, 2014; WHO, 2021). In our survey, among respondents who did not initiate vaping between baseline and follow-up, about 15% of this sample had tried vaping or vaped occasionally (less than monthly) prior to their baseline survey.