eLetters

516 e-Letters

  • Gateway effect from vaping to smoking likely to be small

    NOT PEER REVIEWED
    The meta-analysis by Khouja et al. confirms the strong association in young people between e-cigarette use and subsequent smoking.[1] The critical issue is whether the relationship is causal. If there is a causal relationship, there are several factors which diminish its impact.

    Firstly, most of the studies used ‘ever smoking’ as the outcome. Ever smoking is a poor marker for smoking-related harm as most smoking by vapers who later smoke is experimental and infrequent and few progress to established smoking (100+ lifetime cigarettes). Shahab et al. found that only 2.7% of youth who tried e-cigarettes first progressed to established smoking. Only established smoking is linked to significant smoking-related death and disease.[2]

    Secondly, the absolute number of non-smokers who progress from vaping to smoking is small as smoking precedes vaping in the vast majority of cases (70-85%).[3] If there is a gateway from vaping to smoking, this only affects a minority of young vapers.

    Thirdly, the authors use Bradford Hill’s dose-response and specificity criteria to assess whether the association between vaping and subsequent smoking is likely to be causal.

    They acknowledge that the dose-response criterion is mostly based on nicotine dependence, indicating that that nicotine dependent vapers are more likely to progress to smoking. However, nicotine dependence in non-smoking vapers is rare, less than 4% in the 2018 National Youth T...

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  • RESPONSE

    NOT PEER REVIEWED
    This is a well written original research about the burning issue of tobacco manufacturer lobbying. These manufacturing industries have developed strategies to undercut minimum price laws. By increasing tobacco taxes an effective policy has been designed to decrease tobacco use. In Pakistan currently, 209 million people smoke and about 83 billion cigarettes are smoked per year. As Pakistan has not ratified any anti-smoking policies, there should be great effort made to raise excise duties and taxes on tobacco companies to reduce the demand for cigarettes. In 2017 the local price of cigarettes was about 75 rupees of which half was excise duties [1].
    With this expansion of taxes, there will be responses of reducing tobacco consumption, but the cigarette manufacturing industries developed specific promotions and lobbies to encourage their consumers to purchase lower taxed or lower priced tobacco products. It is the responsibility of health authorities to regulate the prices and promotion of such hazardous products [2]. According to WHO, “MPOWER” was the slogan in 2015, according to which M= monitor tobacco usage, P= Protect people from tobacco smoke, O= offering help to quit tobacco use, W= warning about its hazards, E= enforce to ban its advertisement, R = Raise tobacco taxes [3].
    For smoke free Pakistan and all over the world four key factors should be instruments: Education, legislation, quitting support and financial policies.

    1....

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  • Irresponsible methodology

    NOT PEER REVIEWED

    The atomizer used for testing has a maximum rating of 80 watts.
    200 watts was applied. Needless to say, horrible results occurred.
    This is not reputable science, it is a failed experiment, it should never have been published.

  • Carbon Monoxide to be expected with combustion

    NOT PEER REVIEWED

    It should be noted that the Aspire Cleito coils used in this study have a manufacturer stated operating power range of between 55 and 75 watts. This is noted both on the box and laser etched into the side of the coil housing proper. it should be noted that the first data points in the graph ( to demonstrate the presence of CO in both liquid samples are in excess of the stated power range of the element.

    "Strawnana" at 80 watts
    "Black Ice" at 100 watts

    This leads me to question the normalizing curve for the black ice sample as there are no data points in the graph (Figure 2) within the manufacturer noted operating range for that coil.

    Furthermore, while this statement " ...though the bulk liquid temperature is controlled by boiling limits of the e-liquid component" would be accurate were the coil to be completely submerged in liquid, the mechanics of coil design will confound that principle. The resistance coils in electronic cigarettes are not, by design, submerged in liquid, they are in contact with a liquid saturated wick. Any heat energy applied to the coil whether in magnitude or duration, that exceeds the supply of liquid saturating the wick will result in a temperature spike which could cause the temperature to spike causing thermal degradation of what liquid does remain, and the singeing of the cotton wick.

    It can be expected that where combustion occurs, carbon compounds will...

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  • Declines in Adolescent Use of Cigarettes and Other Substances Consistent With Common Liability Model

    NOT PEER REVIEWED
    Miech and colleagues demonstrate declines in prevalence of non-medical use of prescription drugs among US high school students and show that these declines can be explained by trends in cigarette smoking.1 These observations are taken as support of the gateway hypothesis in which cigarette smoking increases the likelihood of subsequent other drug use. The authors further argue that these results are inconsistent with a ‘common liability’ model, and that the common liability model predicts that adolescent drug use would have “stayed steady or even increased as adolescents continued to use these drugs regardless of whether they smoked.” In this scenario, adolescents with a predilection toward substance might substitute cigarettes with other drugs as smoking rates decline.

    However, this conceptualization of the common liability model is inconsistent with how such models are typically understood. Models that posit a common liability do not assert that the degree of liability is fixed in the population, such that changes in risk for use of one drug increases risk for other drug use. Instead, common liability can be influenced by environmental factors and environmental changes can coherently impact multiple outcomes, resulting in trends similar to those observed by Miech and colleagues.

    For over 40 years, Problem Behavior Theory has provided a comprehensive theory and empirical approach to common liability. “Problem behaviors” (later termed...

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  • A different interpretation

    NOT PEER REVIEWED
    A key finding of this paper does not find its way into the abstract namely, "no significant differences in wheezing and related respiratory symptoms was found when comparing current vapers who never smoked with never smokers. " This tends to suggest, unsurprisingly, that it is the prior smoking history that is the critical factor in current wheeze. The paper supports the harm reduction hypothesis for switching to vaping completely from smoking as per the conclusion. But the conclusion also states in the first line, "Vaping was associated with increased risk of wheezing and related respiratory symptoms, " which is incorrect without adding "in current smokers." Vapers who previously smoked have lower risk than those who continue to smoke, including dual users, and those who never smoked have no increased risk.

  • Up in smoke: The reported association between e-cigarette use and wheezing in this study is probably spurious

    NOT PEER REVIEWED

    We read with interest a recent publication by Li, et. al, entitled Association of smoking and electronic cigarette use with wheezing and related respiratory problems in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2. The primary finding, reported in the abstract, was that risk of wheezing and related respiratory symptoms was significantly increased in current exclusive e-cigarette users compared to never users, with an adjusted odds ratio of 1.67 (1.23, 2.15). We think the report is misleading for several reasons.

    First, the main multivariable analysis (Table 2) did not adequately adjust for important confounders that impact wheeze, most importantly, cigarette smoking history. In most analyses of medical outcomes in adults, pack-years of smoking has a strong relation to smoking-related diseases, over-and-above current smoking status. Since three quarters of vapers in the main model were ex-smokers, cigarette smoking history is almost certainly contributing to the size and significance of the main reported finding. Other combustible tobacco use and current marijuana smoking would also be expected to exacerbate cough and wheeze. Our bet is that large numbers of e-cigarette users also use marijuana.

    The authors partially addressed smoking history with a secondary analysis (Table 3), in which they stratified by former smoking status. In that analysis, vaping was not significantl...

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  • A disappointing and baseless attack on a valuable initiative

    NOT PEER REVIEWED
    I hope that Tobacco Control will offer a right of reply to the target of this one-sided criticism. In the meantime, let me put a few points to the authors:

    1. There is no credible analysis (anywhere) of the actual, rather than the imagined, relationship between PMI and the Foundation for a Smokefree World (FSFW - ‘the Foundation’) that suggests PMI exerts material control over the Foundation. Its basic legal documents suggest otherwise. Nor have the authors explained why the Foundation's goal of ending smoking within a generation is somehow a bad thing or insincere.

    2. Nor is there a credible assessment of the relationship between the Foundation and the new Centre for Research Excellence: Indigenous Sovereignty and Smoking (the Centre) that is the subject of criticism in this paper. There are two degrees of separation between the Centre and PMI, and the philosophy of the Foundation is to support centres of excellence and to leave them to get on with their work. The Centre has an excellent (Māori) leader and is quite capable of asserting its independence. How it would somehow do the bidding of PMI is not explained by the authors.

    3. The authors dismiss the Centre’s focus on ‘harm reduction’ and instead emphasise: “the need to shift attention away from individuals to the true source of the problem: commercial tobacco and the companies that sell and promote it.”. While I share the sentiment about individual smoking cessat...

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  • Foundation for a Smoke-Free World and healthy Indigenous futures: an oxymoron? An Evidence-Based Response

    NOT PEER REVIEWED
    Mr. Clive Bates’ response to our article, the Foundation for a Smoke-Free World and healthy Indigenous futures: an oxymoron?, indicates the need to clarify several issues. In this response, we emphasise two key issues:
    1. Organisations claiming to serve the good of the public, but who receive direct or third-party funding from the tobacco industry, are faced with serious conflicts of interest (COI); and
    2. harm reduction is only part of a comprehensive approach to reducing commercial tobacco use.

    As Indigenous peoples, we have an inherent responsibility to protect the health and wellbeing of Indigenous peoples now and for our future generations. The tobacco industry poses, and has posed in the past, a significant threat to our health and wellbeing. Therefore, we are deeply concerned about the Philip Morris-funded Foundation focusing on Indigenous peoples.

    Philip Morris International, the Philip Morris Funded-Foundation and the Centre for Research Excellence: Indigenous Sovereignty and Smoking
    Mr. Bates states that “There is no credible analysis (anywhere) of the actual, rather than the imagined, relationship between PMI and the Foundation for a Smokefree World”. This is incorrect 1-5. Researchers in journals such as The Lancet and Tobacco Control have analyzed key documents from the Foundation, including tax returns and bylaws that highlighted numerous relationship issues and conflicts of interest 1-5.

    Addressi...

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  • Response to Jane Native

    NOT PEER REVIEWED

    Greetings –
    We thank you for your response to our paper. We honor and acknowledge that there are more than 564 Tribal Nations and that each has their own name and language. In this article, we used the term “American Indian,” which was a decision guided by our long-standing work with cultural advisors in Minnesota. While we chose to use the term “American Indian,” we recognize that each Tribe and individual may prefer to use a different term. For additional context, please see another article titled “Why the World Will Never Be Tobacco-Free: Reframing “Tobacco Control” Into a Traditional Tobacco Movement,” available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4984762/

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