73 e-Letters

published between 2018 and 2021

  • Response to Wang, 'Some discrepancies and limitations'


    We would like to thank Mr. Wang for his feedback on our paper, Indicators of dependence and efforts to quit vaping and smoking among youth in Canada, England and the USA.

    With regards to the ‘discrepancies’ in vaping and smoking prevalence between those reported in Table 1 and an earlier publication [1], we have previously published these same estimates [2], along with a description of the survey weighting procedures—which were modified since the first estimates were published (as outlined in a published erratum to the cited publication [3]). Briefly, since 2019, we have been able to incorporate the smoking trends from national ‘gold standard’ surveys in Canada and the US into the post-stratification sampling weights. A full description is provided in the study’s Technical Report [4], which is publicly available (see http://davidhammond.ca/projects/e-cigarettes/itc-youth-tobacco-ecig/).

    Mr. Wang has also noted a change in the threshold used for a measure of frequent vaping/smoking: ≥20 days in past 30 days rather than ≥15 days, as previously reported [1]. We have adopted the convention of reporting using ≥20 days in past 30 days to align with the threshold commonly used by the US Centers for Disease Control for reporting data from the National Youth Tobacco Survey (NYTS), as well as the Population Assessment of Tobacco and Health (PATH) Study and the Mo...

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  • Some discrepancies and limitations


    There’s a published paper by Hammond and colleagues in 2019[1] using the same survey results, but there are some discrepancies.

    1. The Table 2 of the 2019 paper, prevalence of vaping in 2018 for ever, past 30 days are 37.0% (1425), 14.6% (562) in Canada, 32.7% (1276), 8.9% (346) in England and 33.6% (1360), 16.2% (655) in the US, respectively. However, in this article’s Table 1, for vaping in the same year 2018 for ever, past 30 days are 33.2% (1275), 12.1% (463) in Canada, 33.1% (1283), 9.0% (351) in England and 33.1%(1336), 15.7% (635) in the US. More discrepancies can be found on cigarette smoking section as well. These numbers warrant further explanation particularly why numbers in Canada and the US decreased while numbers in England increased? Considering previous correction of numbers to the 2019 paper has raised serious concern among some readers[1], such timely clarification in this article will be very necessary.

    2. The 2019 paper use the criteria of ≥15 days in past 30 days but the current paper adopts different criteria of ≥20 days in past 30 days, for both vaping and cigarette smoking. Further explanation is needed for such change.

    Additionally, a few considerations on possible limitations of the paper’s findings:

    1. Since the invitations were sent to nearly twice more parents than youth themselves according to the technical report[2], responds to survey questions might be biased because study has shown many...

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  • Our primary assertion is not impacted by the limitations in our statistical analyses

    We thank Mr. Clive Bates (1) and Dr. Moira Gilchrist (2) for their reconsideration of our work (3) and previous response where we corrected some errors (4). We also reiterate that all data informing our Industry Watch are publicly available at Tobacco Watcher (https://tobaccowatcher.globaltobaccocontrol.org/) for anyone to analyze. As with any analyses of observational data, there are limitations and we do not disagree with some of the limitations that Gilchrist and Bates point out in our analyses (as we addressed nearly all of these in our previous response (4)). However, we remain unchanged in our conclusion that, as the title of our initial article stated, “Philip Morris International used the e-cigarette, or vaping, product use associated lung injury (EVALI) outbreak to market IQOS heated tobacco” (3).

    While statistical analysis indicated a correlation between (a) PMI’s public statements regarding EVALI and their IQOS brand of heated tobacco posted to their corporate “media center” (5) and (b) trends in news coverage of EVALI and IQOS, our primary assertion is that PMI used EVALI to market IQOS. The necessary and sufficient analysis to substantiate this assertion is reporting what PMI publicly claimed, which we did by analyzing the statement made by PMI which promoted IQOS through mentioning, contrasting or describing it along with EVALI and/or vaping.

    The full text...

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  • Hagen's response to the authors


    Thank you for the corrections and for acknowledging the omission. The additional analysis performed by ITC is greatly appreciated and provides further insight into the impact of both interventions. Although unstated, Canada’s regional characterizing flavour bans contributed significantly to the development of a national menthol additive ban as chronicled by the U.S. Tobacco Control Legal Consortium[1] . I look forward to reading the full analysis when published.

    1. Kerry Cork, Tobacco Control Legal Consortium, Leading from Up North: How Canada Is Solving the Menthol Tobacco Problem (2017). https://www.publichealthlawcenter.org/sites/default/files/resources/tclc...

  • Increasing quitting in older smokers should be top priority in rich countries

    Reducing smoking rates in older smokers will achieve a far greater reduction in deaths & disease and do this much earlier than reducing already much lower smoking rates in teens & young populations. Tobacco harm reduction (THR) options, such as vaping, Heated Tobacco Products (HTP), snus & nicotine pouches, all avoid inhalation of smoke from tobacco combustion and are less risky than smoking cigarettes which are responsible for the death of more than 50% of long term smokers. Cigarette sales in Japan declined by over 40% in five years after HTPs entered the Japanese market in 2016. There are now many other examples of other THR options substituting for deadly cigarettes in other countries.
    New drug harm reduction interventions usually face fierce opposition for many years after their introduction. Needle syringe programs to reduce HIV spread among and from people who inject drugs were still strongly resisted long after the evidence for their effectiveness, safety and cost effectiveness was incontrovertible. It is not surprising to me therefore, as a veteran of many battles over new drug harm reduction interventions, to observe the acrimonious debate over THR.
    If it is made easy for older smokers to switch to THR options, the benefits will not only be an acceleration in the decline of smoking related deaths and disease, but also a more rapid decline in cigarette sales.

  • Authors’ response to L Hagen

    In his comment, Les Hagen brings up an important distinction between two types of restrictions on menthol: a menthol additive ban, and a menthol characterizing flavour ban. Canada's menthol ban across the provinces did indeed involve both types. Between May 2015 and July 2017, Nova Scotia, Alberta, Quebec, Ontario, Prince Edward Island, and Newfoundland & Labrador implemented characterizing flavour bans, whereas New Brunswick implemented a menthol additive ban [1]. When the Federal Government implemented a menthol additive ban in October 2017 [2] , it applied only to the remaining provinces—British Columbia, Saskatchewan, Manitoba—as well as Nunavut, Yukon, and the Northwest Territories. Thus, the "menthol cigarette ban" in Canada is a mixture of the two types.

    Our article [3] evaluated the impact of menthol bans implemented between the 2016 and 2018 waves of the Canadian arm of the ITC Four Country Smoking and Vaping Surveys. Hagen incorrectly stated that "the analysis was performed exclusively on provincial characterizing flavour bans." In fact, the provinces evaluated in our study included both those that implemented characterizing flavour bans (Quebec, Ontario, Prince Edward Island, Newfoundland & Labrador) and those that implemented the Federal menthol additive ban (British Columbia, Saskatchewan, Manitoba).

    In our original study, we did not test for differences between the two kinds of bans, beca...

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  • In Response to Michael Pesko's Comments "Scientific Concerns"

    We thank Pesko for his comments and the opportunity for us to respond and clarify.

    First, we appreciate Pesko’s clarification that Cotti et al. (2020) clustered standard errors to account for clustering. In the present study, we used multilevel analysis not only to account for clustering of respondents (i.e., design effects) but also to incorporate different error terms for different levels of the data hierarchy which yields more accurate Type I error rates than nonhierarchical methods where all unmodeled contextual information ends up pooled into a single error term of the model.

    Second, we understand that Cotti et al. (2020) evaluated the magnitude of e-cigarette tax values, which does not contradict to our statement because our study focused on the effects of e-cigarette excise tax policies on individual e-cigarette use and prevalence rather than aggregated sales at state or county levels. We also clearly described the reason why we examined the e-cigarette excise tax policy implementation indicator rather than its magnitude in our paper’s discussion section.

    Third, our study used a nationally representative sample of young adults (rather than a nationally representative sample of general adult population). While we understand Pesko’s concern that a sample’s representativeness might be lost when subgroups are explored, we believe our use of sampling weights in analysis has reduced such a concern.

    Fourth, in Table 3,...

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  • In Response to Clive D Bates' Comments "By ignoring the impact of a vaping tax on smoking, the paper misses the most important point"


    We appreciate the comments from Bates and the opportunity for us to respond and clarify.

    First, Bates' argument heavily relies on the assumption that e-cigarettes and combustible cigarettes are substitutes, which is theoretically possible as some consider vaping as a harm reduction alternative to combustible cigarettes. Empirically, however, there have been mixed findings about whether e-cigarettes and combustible cigarettes are substitutes (or complements). Bates cited Pesko et al. (2020) that concludes e-cigarettes and combustible cigarettes are substitutes, whereas other studies have shown that they are complements. For example, Cotti et al. (2018) found that higher cigarette excise taxes, in fact, decrease sales of both e-cigarettes and combustible cigarettes, suggesting that they are complements. Such mixed results abate Bates' argument that taxing ENDS could lead to more use of combustible cigarettes.

    Second, Bates might have ignored that our study focused on young adults aged 18-24 years rather than general adults when examining the effect of vaping product tax on e-cigarette use. Although Pesko et al. (2020) suggests that e-cigarettes and combustible cigarettes are substitutes, the findings are based on the general adult population (average age: 55 years) which may not be generalizable to the young adult population. In fact, one study conducted by Abouk and Adams (2017) indicates that e-cigarettes and combustible ci...

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  • Scientific Concerns

    I have a number of concerns with the paper as currently written.

    1) The authors write: “Besides, none of the previous studies except Pesko et al (15) that examined the associations between vaping product excise tax adoption and ENDS use has accounted for the clustering of respondents within the same localities…” This is not accurate, as citation 19 also clusters standard errors at the locality level in all specifications.

    2) The authors write: "A working paper reported reduced ENDS sales, but not ENDS use prevalence or behaviours, after implementation of a vaping product excise tax policy. (19)” This is not accurate, as the cited study uses the magnitude of e-cigarette tax values, rather than an indicator variable for tax implementation. States have adopted e-cigarette taxes of different magnitudes and a number of them (such as California) have changed the magnitudes of these taxes after adoption. All of this variation is used in citation 19, contrary to the current study’s description. It's also unclear from the sentence whether citation 19 studied use and found imprecise estimates, or did not study use. It's the latter and this should be clarified. It's also unclear why the authors did not use magnitude of e-cigarette taxes themselves in the current paper, as has been commonly done in the referenced literature.

    3) Authors write they use a “nationally representative sample of US young adults.” I do not beli...

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  • Omission of reporting characterizing flavour bans

    This article does not distinguish between characterizing flavour (menthol) bans that were implemented in Canadian provinces between 2015 and 2017 and the implementation of a national ban on menthol additives in Canada in October 2017. Although unreported, the analysis was performed exclusively on provincial characterizing flavour bans. This significant distinction should be reported to ensure that researchers and policy makers are aware of the potential impact of a characterizing flavour ban and to ensure that this policy measure is not dismissed or discounted.