497 e-Letters

  • 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.

  • By ignoring the impact of a vaping tax on smoking, the paper misses the most important point

    I would like to make three comments by way of a brief post-publication review.

    1. The impacts of vaping tax on smoking have been completely overlooked

    For a study of e-cigarette taxation to have any public health relevance, it must consider the impact of e-cigarette prices on *cigarette* demand. Cigarettes and e-cigarettes are economic substitutes. The demand for one responds to changes in the price of the other, an idea well understood in economics and quantified through the concept of cross-elasticity. The paper appears to pay no regard to the impact of vaping taxes on cigarette demand, Yet such effects might easily overwhelm any benefits from reduced e-cigarette use - in fact, impact on demand for other tobacco products and the development of informal markets are by far the most important impacts of a vaping tax. By way of example, a 2020 paper by Pesko et al. [1] concluded:

    "Our results suggest that a proposed national e-cigarette tax of $1.65 per milliliter of vaping liquid would raise the proportion of adults who smoke cigarettes daily by approximately 1 percentage point, translating to 2.5 million extra adult daily smokers compared to the counterfactual of not having the tax."

    2. The case for reducing adult vaping by taxation has not been made

    The authors have based their paper on an unexamined assumption that it is a justifiable goal of policy to lower rates of adult e-cigarette use. Why should...

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  • Authors’ Response Reveals Several New and Serious Issues

    Replication attempts are one of the self-correcting mechanisms of science, and we thank the Authors for their response to our concerns and their attempt to replicate aspects of their study [1]. Regrettably, they have failed to adequately address the central point raised in our letter of 23rd April 2021, namely that the title and conclusions of their original Article are patently invalid and have no basis in fact or evidence [2]. Instead of strengthening their argument in support of the Article’s findings and conclusions, the Authors’ response considerably weakens them. Strikingly, the Authors reveal several new and serious issues and yet maintain that their “principle finding is unchanged”.

    Methodological Problems:

    The Authors acknowledge that they were unable to replicate an important aspect of their original analysis, namely that a Philip Morris International (PMI) News Article [3] published on its website (falsely described as a “press release”) was “republished […] in 14 additional news outlets”. In their response, they note that “Our original assertion that there were 14 duplicate articles is not supported by our replication analysis”. This failure to replicate a key finding—in their own proprietary database, which several of them co-developed—is concerning. The Authors provide no explanation for the irregularity. Notably, on 20th April 2021, we were able to source these 14 articles in Tobacco Watcher since they were clearly mar...

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  • The authors' response to criticisms suggests White Hat Bias

    The authors’ response published on 14 July 2021 is far from satisfactory and implausibly asserts that “Our original findings and conclusions remain plausible” [1]

    The original study [2] uses a media analysis to make a claim that a statement made by the tobacco company Philip Morris International (PMI) about an outbreak of lung disease in the US [3] was a marketing ploy for its heated tobacco product, iQOS. At the time, the lung injury outbreak was falsely attributed by many to nicotine vaping. Heated tobacco products are an alternative to nicotine vaping for smokers looking for a low-risk alternative to smoking.

    I will now list some of the problems with this claim.

    1. The research findings do not support the headline claim

    The study title contains a strong and unqualified assertion of cynical opportunism on the part of the company. The new formulation that findings "remain plausible" does not justify the confidence in the assertion made in the title. "Plausible" is a reasonable basis for choosing a hypothesis to investigate, but a far from sufficient basis for drawing an aggressive conclusion. The authors do not seem to dispute the technical or factual accuracy of the statement about iQOS and EVALI made by PMI. Their allegation is about malign motives and, as such, it should be a cause for caution and a high standard of evidence.

    2. No specific articles were provided to substantiate the...

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