Berry et al (1) report an analysis of two waves of the Population Assessment of Tobacco and Health (PATH) study focused on the association between the initiation of e-cigarette use by Wave 2 and cigarette abstinence/reduction assessed at Wave 2. They conclude that daily e-cigarette use is associated with both cigarette abstinence and reduced consumption among continuing smokers. While this addresses an important question, we argue that such analyses should be adjusted for the reason e-cigarettes are being used.
From Wave 1 of PATH (2), we know that ~75% of smokers agreed that e-cigarettes were useful to help people quit. However, ~80% agreed that e-cigarettes allowed someone to replace a cigarette where smoking was prohibited. From the first reason, we can hypothesize that e-cigarette use might be associated with cigarette abstinence/reduction. However, from the second reason, we can also hypothesize that e-cigarettes would be associated with neither cigarette abstinence nor reduction. The recent National Academies report (3) recommended that any assessment of the role of e-cigarettes in cigarette cessation/reduction should focus on smokers who used e-cigarettes to help them quit.
PATH Wave 2 data does include information on whether smokers tried to quit in the previous year, as well as whether they used e-cigarettes to aid the last quit attempt. Previous research (4) has shown that over half of the smoking population will not ha...
Berry et al (1) report an analysis of two waves of the Population Assessment of Tobacco and Health (PATH) study focused on the association between the initiation of e-cigarette use by Wave 2 and cigarette abstinence/reduction assessed at Wave 2. They conclude that daily e-cigarette use is associated with both cigarette abstinence and reduced consumption among continuing smokers. While this addresses an important question, we argue that such analyses should be adjusted for the reason e-cigarettes are being used.
From Wave 1 of PATH (2), we know that ~75% of smokers agreed that e-cigarettes were useful to help people quit. However, ~80% agreed that e-cigarettes allowed someone to replace a cigarette where smoking was prohibited. From the first reason, we can hypothesize that e-cigarette use might be associated with cigarette abstinence/reduction. However, from the second reason, we can also hypothesize that e-cigarettes would be associated with neither cigarette abstinence nor reduction. The recent National Academies report (3) recommended that any assessment of the role of e-cigarettes in cigarette cessation/reduction should focus on smokers who used e-cigarettes to help them quit.
PATH Wave 2 data does include information on whether smokers tried to quit in the previous year, as well as whether they used e-cigarettes to aid the last quit attempt. Previous research (4) has shown that over half of the smoking population will not have tried to quit in the previous year. By including these non-attempters, who by definition cannot have quit, Berry et al (1) may have introduced an important bias toward finding a higher daily e-cigarette effect on abstinence. We expect that daily e-cigarette use at Wave 2 will be much higher among those who made a recent quit attempt than in those who did not.
In their supplement tables (TableS3), they include an analysis of those who made a quit attempt prior to Wave 1(rather than between Waves 1 and 2). Using this analysis, there is a drastic reduction in the effect size amplitude and in the absolute number of involved smokers. We would expect similar, or even larger, reduction in effect estimates were they to have restricted their analysis to those who made a quit attempt in the year prior to Wave 2 and included reason for using e-cigarettes.
In order to know the effect of e-cigarettes on cessation, those who used an e-cigarette to help them to quit should be contrasted with comparable non-users: those who used other aids to quit as well as to those who quit unaided. There are numerous important potential confounders for these comparisons as it is well known that those who are least likely to be successful in the quit attempt are the most likely to use an aid. (5) For unbiased analyses, the exposure of interest needs to be isolated and covariate balance achieved between exposed and unexposed. There is a role for methodological approaches that help achieve covariate balance, such as propensity score matching, in deciding whether e –cigarettes improve population smoking cessation.
References:
1. Berry KM, Reynolds LM, Collins JM, Siegel MB, Fetterman JL, Hamburg NM, Bhatnagar A, Benjamin EJ, Stokes A. E-cigarette initiation and associated changes in smoking cessation and reduction: the Population Assessment of Tobacco and Health Study, 2013-2015.Tob Control. 2018 Mar 24. pii: tobaccocontrol-2017-054108. doi: 10.1136/tobaccocontrol-2017-054108.
2. Coleman BN, Rostron B, Johnson SE, Ambrose BK, Pearson J, Stanton CA, et al. Electronic cigarette use among US adults in the Population Assessment of Tobacco and Health (PATH) Study, 2013–2014. Tobacco Control. 2017. doi: 10.1136/tobaccocontrol-2016-053462.
3. National Academies of Sciences Engineering, and Medicine,. Public Health Consequences of E-Cigarettes. Washington, DC: Health and Medicine Division, National Academies of Sciences, Engineering, and Medicine, 2018
4. Zhu S-H, Lee M, Zhuang Y, Gamst A, Wolfson T. Interventions to increase smoking cessation at the population level: How much progress has been made in the last two decades? Tob Control. 2012;212:110–118
5. Leas EC, Pierce JP, Benmarhnia T, White MM, Noble ML, Trinidad DR, Strong DR. Effectiveness of Pharmaceutical Smoking Cessation Aids in a Nationally Representative Cohort of American Smokers. J Natl Cancer Inst. 2017 Dec 21. doi: 10.1093/jnci/djx240
NOT PEER REVIEWED
Coleman et al’s important report [1] on transitions in the vaping and smoking status of a nationally representative cohort of American 18+ adults who use electronic cigarettes (EC) from the PATH study provides rich data that can greatly advance our understanding of the natural history of EC use and their potential in harm reduction.
However, we were struck by the absence of emphasis in the report of what is perhaps its most important finding. If we examine the report’s data and consider the net impact of vaping on the critical goals of having vapers stopping smoking and vaping non-smokers not starting to smoke, the findings are very disturbing and should strong reason for pause among those advocating e-cigarettes as a game-changing way of stopping smoking.
At Wave 2, 12 months on from Wave 1, of the cohort of 2036 dual users (EC + smoking) only 104 (5.1%) had transitioned to using only EC and another 143 (7%) had quit both EC and smoking for a combined total of 247 or 12.1%. Of the 896 exclusive EC users at Wave 1, 277 (30.9%) had stopped vaping at Wave 2. Together, 524 out of the 2932 EC users (17.9%) followed from Wave 1 might be considered to have had positive outcomes at Wave 2.
The other side of the coin however, shows that of the 2036 dual users at Wave 1, 886 (43.5%) relapsed to using cigarettes exclusively. In addition, among the 896 exclusive EC users from Wave 1, 109 (12.2%) had stopped vaping and were now smoking, wit...
NOT PEER REVIEWED
Coleman et al’s important report [1] on transitions in the vaping and smoking status of a nationally representative cohort of American 18+ adults who use electronic cigarettes (EC) from the PATH study provides rich data that can greatly advance our understanding of the natural history of EC use and their potential in harm reduction.
However, we were struck by the absence of emphasis in the report of what is perhaps its most important finding. If we examine the report’s data and consider the net impact of vaping on the critical goals of having vapers stopping smoking and vaping non-smokers not starting to smoke, the findings are very disturbing and should strong reason for pause among those advocating e-cigarettes as a game-changing way of stopping smoking.
At Wave 2, 12 months on from Wave 1, of the cohort of 2036 dual users (EC + smoking) only 104 (5.1%) had transitioned to using only EC and another 143 (7%) had quit both EC and smoking for a combined total of 247 or 12.1%. Of the 896 exclusive EC users at Wave 1, 277 (30.9%) had stopped vaping at Wave 2. Together, 524 out of the 2932 EC users (17.9%) followed from Wave 1 might be considered to have had positive outcomes at Wave 2.
The other side of the coin however, shows that of the 2036 dual users at Wave 1, 886 (43.5%) relapsed to using cigarettes exclusively. In addition, among the 896 exclusive EC users from Wave 1, 109 (12.2%) had stopped vaping and were now smoking, with another 121 having resumed smoking as well as using EC (i.e. became dual users). Importantly, 502 of 896 (56%) exclusive e-cigarette users were those who had never been established smokers prior to using e-cigarettes. Alarmingly, of these 502 adults, 120 (23.9%) progressed from using only e-cigarettes to either dual use (54 or 10.8%) or smoking only (66 or 13.2%).
Taken together, 886 dual users in Wave 1 relapsed to become exclusive cigarette smokers in Wave 2, and 230 exclusive vapers in Wave 1 took up cigarette smoking in Wave 2 (dual use or exclusively cigarettes). Undoubtedly, these should be considered as negative outcomes.
The table below shows that for every person vaping at Wave 1 who benefited across 12 months by quitting smoking, there are 2.1 who either relapsed to or took-up smoking. Most disturbingly, in this adult cohort nearly one in four of those who had never been established smokers took up smoking after first using EC. Concern about putative gateway effects of ECs to smoking have been dominated by concerns about youth. These data showing transitions from EC to smoking in nearly a quarter of exclusive adult EC users with no histories of established smoking should widen this debate to consider adult gateway effects too.
By far the largest proportion of those with negative outcomes are those dual users who relapsed to smoking (886 or 43.5% of dual users). As the authors note in their discussion, many of these were infrequent EC users, possibly involved in transitory experimentation at Wave 1. If we add the 902 who were still dual using at Wave 2, then 1788 of 2036 dual users (87.8%) in this sample might be said to have been held in smoking (dual using or exclusive smoking) 12 months later compared to 12.1% dual users who may have benefitted by using ECs.
We would expect commercial interests in both the tobacco and EC industries would be more than delighted with these findings. However, from a public health harm reduction perspective these results argue against EC being an effective harm reduction strategy, and point to their far stronger potential to both recruit smokers and hold many smokers in smoking.
Reference
1. Coleman B et al Transitions in electronic cigarette use among adults in the Population Assessment of Tobacco and Health (PATH) Study, Waves 1 and 2 (2013-2105). Tobacco Control 2018; doi:10.1136/tobaccocontrol-2017-054174
NOT PEER REVIEWED
The paper by Filippidis et al [1] provides data re-confirming the well-known fact that most ex-smokers attempt to quit without using any form of assistance, whether pharmaceutical, professional or via e-cigarettes. Moreover, the proportion of ex-smokers trying to quit unaided increased substantially in Europe between 2012-17 (ex-smokers using no assistance increased from 73.9% to 80.7%), a period where e-cigarette use accelerated in some nations.
Regrettably however, this study does not permit any comparison of success rates by method, as no data are reported on which method of cessation (assisted v unassisted) was used by ex-smokers on their last, final (and so successful) quit attempt.
The authors report that those “who successfully quit reported much lower use of cessation assistance compared with smokers who had tried to quit without success” and suggest that this might reflect indication bias, whereby those who find it harder to quit self-select to use assistance, leaving the low hanging fruit of non- or less addicted smokers to fall off the smoking tree using their own determination.
While this will be true for some, there are many former heavy smokers who quit without assistance. This argument also borrows assumptions from the discredited hardening hypothesis [2], which holds, in the face of evidence to the contrary, that as smoking prevalence falls the concentration of hardened, more deeply addicted smokers increase...
NOT PEER REVIEWED
The paper by Filippidis et al [1] provides data re-confirming the well-known fact that most ex-smokers attempt to quit without using any form of assistance, whether pharmaceutical, professional or via e-cigarettes. Moreover, the proportion of ex-smokers trying to quit unaided increased substantially in Europe between 2012-17 (ex-smokers using no assistance increased from 73.9% to 80.7%), a period where e-cigarette use accelerated in some nations.
Regrettably however, this study does not permit any comparison of success rates by method, as no data are reported on which method of cessation (assisted v unassisted) was used by ex-smokers on their last, final (and so successful) quit attempt.
The authors report that those “who successfully quit reported much lower use of cessation assistance compared with smokers who had tried to quit without success” and suggest that this might reflect indication bias, whereby those who find it harder to quit self-select to use assistance, leaving the low hanging fruit of non- or less addicted smokers to fall off the smoking tree using their own determination.
While this will be true for some, there are many former heavy smokers who quit without assistance. This argument also borrows assumptions from the discredited hardening hypothesis [2], which holds, in the face of evidence to the contrary, that as smoking prevalence falls the concentration of hardened, more deeply addicted smokers increases.
If our concern is (as it should be) to better understand the means of quitting that produce the largest net volume of ex-smokers across whole populations, studying the methods these former smokers used when they succeeded is critical. Yet the “inverse impact law of smoking cessation [3] shows that unassisted cessation, which undisputedly delivers more ex-smokers than any other method, is hugely neglected in smoking cessation research [4].
It is almost as if researchers want to turn away from learning more about the most successful route that has always delivered the largest number of successful quits. [5]
Rather than seeing the increase in unassisted quitting as something to be highlighted as a positive, motivating celebration of agency that could be megaphoned in campaigns to smokers imbued with pessimistic messages about how hard quitting is going to be, the authors conclude that their findings ”highlight the need for approaches to ensure that smokers get support”.
In 40 years of tobacco control, I cannot ever recall attending a meeting or conference on cessation where those whose living depended on them selling smoking cessation aids or providing professional cessation services did not reach similar conclusions. Yet 40 years on, the same cracked record is being played: we need to convince more smokers that they should not try foolishly to quit alone and that they need our help!
Analysis at the level of the success of quit “attempts” often shows that head-to-head, unassisted cessation attempts are less successful than those using assistance. But many so-called cessation attempts are empty gestures akin to those who attempt to get fit by buying an exercise bike, use it once or twice and then consign it to the corner. West and Sohal’s work on catastrophe theory noted that many who were not planning to quit at time 1, had succeeded at time 2. They suggested that “smokers have varying levels of motivational “tension” to stop and then “triggers” in the environment result in a switch in motivational state. If that switch involves immediate renunciation of cigarettes, this can signal a more complete transformation than if it involves a plan to quit at some future point.” [6]
The importance of continually stimulating the motivational tension to stop smoking and providing both informational and policy triggers for quitting cannot be over-emphasised.
It is long overdue that we gave far more attention to the net contribution of unassisted cessation at the population level. [7 ] Many smokers have little interest in being helped to quit. In this, they are very aware of many friends and acquaintances who quit alone when they were sufficiently motivated to do so. Over 40 years of professional hand-wringing, research and campaigning about how to undermine unaided quitting and sell more drugs and clinic appointments have thankfully done little to erode this.
References
1. Filippidis FT, Mons U, Jiminez-Ruiz C, Vardavas CI. Changes in smoking cessation assistance in the European Union between 2012 and 2017: pharmacotherapy versus counselling versus e-cigarettes. Tobacco Control http://dx.doi.org/10.1136/tobaccocontrol-2017-054117
2. Cohen JE, McDonald PW, Selby P. Softening up on the hardening hypothesis. Tobacco Control ttp://dx.doi.org/10.1136/tobaccocontrol-2011-050381
3. Chapman S. The Inverse Impact Law of Smoking Cessation. Lancet 2009; 373(9665):701-3.
4. Chapman S, Mackenzie R. The global research neglect of unassisted smoking cessation: causes and consequences. PLoS Medicine 2010; 7(2): e1000216. doi:10.1371/journal.pmed.1000216.
5. Smith A, Chapman S. Quitting unassisted: the 50 year neglect of a major health phenomenon. JAMA 2014;311(2):137-138. doi:10.1001/jama.2013.282618.
3. West R, Sohal T. “Catastrophic” pathways to smoking cessation: findings from national survey. BMJ. 2006 Feb 25; 332(7539): 458–460.
doi: 10.1136/bmj.38723.573866.AE
4. Smith A, Carter SM, Chapman S, Dunlop S, Freeman B. Why do smokers try to quit without medication or counseling? A qualitative study with ex-smokers. BMJ Open 5:e007301 doi:10.1136/bmjopen-2014-007301
Feliu et al’s conclusion “in the European Union countries with the higher scores in the Tobacco Control Scale, which indicates higher tobacco control efforts, have lower prevalence of smokers, higher quit ratios and higher relative decreases in their prevalence rates of smokers.” deserved comment.
First, it seems a tautology. Tobacco control policies are robustly evidence based. Accordingly, more efforts, less smokers.
Second, a PubMed search with “"tobacco control scale" only retrieved 27 articles since 2006 and no validation published yet. Obviously, the Scale poorly correlated with smoking rate: r2 being .58 in 2002/3, .15 in 2006/7 and .06 in 2010/11.(From table 3 in 2; n= 11 European countries).
Third, why make simple stuff complex? This surrogate is complex to calculate and its items are subjective because issuing a decree is useless if no implementation were enforced. In contrast, the smoking rate and its evolution are simple and reliable! How France can be ranked 4th among 28 countries with a 57/100 score (1) while smoking prevalence has been plateauing for so long at more than 30%? In France, from 2004 to 2017 no relevant increase in tobacco taxes, no implementation of the legal smoking ban in cafés or of the ban of sale to minors despite sting operations by NGO showing evidence of serious breaches.(3)
Fourth, claiming “the European Union should continue implementing comprehensive tobacco control pol...
Feliu et al’s conclusion “in the European Union countries with the higher scores in the Tobacco Control Scale, which indicates higher tobacco control efforts, have lower prevalence of smokers, higher quit ratios and higher relative decreases in their prevalence rates of smokers.” deserved comment.
First, it seems a tautology. Tobacco control policies are robustly evidence based. Accordingly, more efforts, less smokers.
Second, a PubMed search with “"tobacco control scale" only retrieved 27 articles since 2006 and no validation published yet. Obviously, the Scale poorly correlated with smoking rate: r2 being .58 in 2002/3, .15 in 2006/7 and .06 in 2010/11.(From table 3 in 2; n= 11 European countries).
Third, why make simple stuff complex? This surrogate is complex to calculate and its items are subjective because issuing a decree is useless if no implementation were enforced. In contrast, the smoking rate and its evolution are simple and reliable! How France can be ranked 4th among 28 countries with a 57/100 score (1) while smoking prevalence has been plateauing for so long at more than 30%? In France, from 2004 to 2017 no relevant increase in tobacco taxes, no implementation of the legal smoking ban in cafés or of the ban of sale to minors despite sting operations by NGO showing evidence of serious breaches.(3)
Fourth, claiming “the European Union should continue implementing comprehensive tobacco control policies in Europe.”(1) is optimistic, at best. The European Union is the chimney of rich countries: smoking prevalence in Italy, France and Germany is almost twice that in Australia and 1.5 fold that in the US. Almost no tobacco control in the European Union but Finland! The Scale is a smokescreen for tricky politicians cherry picking the weakest measures without even providing tools for implementation or monitoring.
Last, I am not aware that a critical assessment of the Eurobarometer method is available, and the limitations of such surveys cannot be overlooked. This deserves scrutiny as other data from the European Union on such a topic are a cause for concern: eg. the European School Project on Alcohol and other Drugs estimates smoking prevalence only on a declarative basis, roughly 10% of the data are missing despite only recruiting those attending school and only 80 % of the students said that they thought that their classmates had answered the questions honestly.(4)
1 Feliu A, Filippidis FT, Joossens L et al. Impact of tobacco control policies on smoking prevalence and quit ratios in 27 European Union countries from 2006 to 2014. Online Feb 22.
2 Kuipers MA, Monshouwer K, van Laar M, Kunst AE. Tobacco control and socioeconomic inequalities in adolescent smoking in Europe. Am J Prev Med 2015;49:e64-e72.
3 Braillon A, Mereau AS, Dubois G. [Tobacco control in France: effects of public policy on mortality]. Presse Med 2012;41:679-81.
4 Hibell B, Molinaro S, Siciliano V, Kraus L. The 2013 ESPAD validity study. European Monitoring Centre for Drugs and Drug Addiction. Publications Office of the European Union. Luxembourg. 2015.
NOT PEER REVIEWED
The reporting of the results of this study is far from complete, which is concerning given the highly politicised controversy that surrounds this product. I hope the authors should respond to this comment by publishing supplementary material with all the data they collected in a an accessible form such a CSV file and summarised in tables in a supplementary memo.
In particular, the authors should provide all data on the following:
+ Vaping and JUUL current use (used in past 30-days) prevalence stratified by age, clearly differentiating between 18 and over and under-18s
+ Frequency of use of vaping products and JUUL within the 30 days among current (past-30 days) users, ideally using the same frequency breakdown used in the National Youth Tobacco Survey
+ Breakdown of vaping status by smoking status and frequency of vaping and JUUL use - to help determine the extent to which regular JUUL use is concentrated among smokers
+ Smoking prevalence and frequency
There is a rare opportunity to gain insights into a live controversy, yet the reporting of the survey is so incomplete it is difficult to draw any serious conclusions from it about the overall effect. For example, JUUL maybe displacing other vaping products used by youth as it is in the market overall. JUUL may be functioning as an alternative to smoking in both adolescents and adults and contributing to achieving smoke-free public health objectives.
NOT PEER REVIEWED
The reporting of the results of this study is far from complete, which is concerning given the highly politicised controversy that surrounds this product. I hope the authors should respond to this comment by publishing supplementary material with all the data they collected in a an accessible form such a CSV file and summarised in tables in a supplementary memo.
In particular, the authors should provide all data on the following:
+ Vaping and JUUL current use (used in past 30-days) prevalence stratified by age, clearly differentiating between 18 and over and under-18s
+ Frequency of use of vaping products and JUUL within the 30 days among current (past-30 days) users, ideally using the same frequency breakdown used in the National Youth Tobacco Survey
+ Breakdown of vaping status by smoking status and frequency of vaping and JUUL use - to help determine the extent to which regular JUUL use is concentrated among smokers
+ Smoking prevalence and frequency
There is a rare opportunity to gain insights into a live controversy, yet the reporting of the survey is so incomplete it is difficult to draw any serious conclusions from it about the overall effect. For example, JUUL maybe displacing other vaping products used by youth as it is in the market overall. JUUL may be functioning as an alternative to smoking in both adolescents and adults and contributing to achieving smoke-free public health objectives.
The Truth Initiative is proud of its advocacy for young people, but as far as presentation and interpretation of data are concerned, such activist commitment amounts to a competing interest. For that reason, everyone, including Truth, is served by full disclosure of the survey data in an appropriate and accessible form and answers to key data questions that would help understand the JUUL phenomenon.
NOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
However, we have demonstrated unambiguously the a...
NOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
However, we have demonstrated unambiguously the absence of formaldehyde cyanohydrin by injecting the reference standard (Sigma, CAS# 107-16-4, ref. 50640). The formaldehyde cyanohydrin is eluting at 11.53 min and does not correspond to the peak eluting just before e-caprolactone that the authors tentatively identified as formaldehyde cyanohydrin (17.97 min under their conditions). This peak, based on existing literature [1] and high resolution mass spectra, is highly likely to be meso-lactide, the third isomers of lactide. The experimental details are available on PMIScience.com (https://www.pmiscience.com/library/publication/analysis-of-polylactic-ac...)
It is well known among analytical chemists that unit mass matching with a single data base is insufficient to prove the identity of a compound. Therefore, we typically use commercially available reference standards to verify our findings. This is important to us, as we are focused on developing reduced risk alternatives to combustible cigarettes. In this context, it is key that our science is always verified to the highest possible standards.
[1] Arrieta MP, Parres-Garcia F, Lopez-Martinez J et al. Pirólisis de residuo de bioplásticos : Productos obtenidos del ácido poliláctico (PLA). Dyna Ingenieria e Industria, 2012 ; 87(4):395-399. doi:10.6036/4673
NOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
However, we have demonstrated unambiguously the a...
NOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
However, we have demonstrated unambiguously the absence of formaldehyde cyanohydrin by injecting the reference standard (Sigma, CAS# 107-16-4, ref. 50640). The formaldehyde cyanohydrin is eluting at 11.53 min and does not correspond to the peak eluting just before e-caprolactone that the authors tentatively identified as formaldehyde cyanohydrin (17.97 min under their conditions). This peak has been confirmed, using the purchased reference standard (NatureWorks, CAS # 13076-19-2), to be meso-lactide, the third isomers of lactide. The experimental details are available on PMIScience.com (https://www.pmiscience.com/library/publication/analysis-of-polylactic-ac...).
It is well known among analytical chemists that unit mass matching with a single data base is insufficient to prove the identity of a compound. Therefore, we typically use commercially available reference standards to verify our findings. This is important to us, as we are focused on developing reduced risk alternatives to combustible cigarettes. In this context, it is key that our science is always verified to the highest possible standards.
NOT PEER REVIEWED
In view of the rising prevalence of adolescent smoking worldwide, it makes a lot of sense to strictly limit cigarette sales only to alcohol licensed premises, particularly, in countries where there are minimum age requirements for buying alcohol. In a previous letter (1) to Lancet Global Health we had argued in favor of the same as we believe that restricting sale of cigarettes or other tobacco products will bring about a decrease in consumption by adolescents.
Smoking addictions are usually acquired during adolescence and this usually happens due to an apparently unregulated sale of tobacco products. Regulation is difficult when the number of tobacco selling establishments far exceeds the managing capacity of local administration. In India, adolescents have unrestricted access to tobacco products as small vendors, whose only source of income is by selling tobacco products, tend not to compromise on any business opportunity.
Although there is a positive association between alcohol and smoking, as the authors have pointed out “tobacco sales are not financially important for the majority of alcohol-licensed tobacco retailers”, so it is a win-win situation for preventing initiation of cigarette smoking by adolescents as alcohol vendors will have no incentive to bypass regulations by selling tobacco products to those who do not qualify as per legal age restrictions. In India, smoking and consumption of alcohol are also social taboos and th...
NOT PEER REVIEWED
In view of the rising prevalence of adolescent smoking worldwide, it makes a lot of sense to strictly limit cigarette sales only to alcohol licensed premises, particularly, in countries where there are minimum age requirements for buying alcohol. In a previous letter (1) to Lancet Global Health we had argued in favor of the same as we believe that restricting sale of cigarettes or other tobacco products will bring about a decrease in consumption by adolescents.
Smoking addictions are usually acquired during adolescence and this usually happens due to an apparently unregulated sale of tobacco products. Regulation is difficult when the number of tobacco selling establishments far exceeds the managing capacity of local administration. In India, adolescents have unrestricted access to tobacco products as small vendors, whose only source of income is by selling tobacco products, tend not to compromise on any business opportunity.
Although there is a positive association between alcohol and smoking, as the authors have pointed out “tobacco sales are not financially important for the majority of alcohol-licensed tobacco retailers”, so it is a win-win situation for preventing initiation of cigarette smoking by adolescents as alcohol vendors will have no incentive to bypass regulations by selling tobacco products to those who do not qualify as per legal age restrictions. In India, smoking and consumption of alcohol are also social taboos and this particular factor in itself might deter adolescents from buying tobacco products. We feel that limiting sale of tobacco products to alcohol-licensed premises will surely prevent initiation of cigarette by adolescents.
References:
1. Barua MP, Mishra V, Kumar S. Reducing adolescent smoking in India. Lancet Glob Health. 2017 Mar;5(3): e266. doi: 10.1016/S2214-109X(17)30036-0. PubMed PMID: 28193389
NOT PEER REVIEWED The Jawad et al systematic review and meta-analysis examining price effects for non-cigarette tobacco and nicotine products appears methodologically sound and was a registered analysis. It provides information that could be used productively by advocates and policymakers seeking to reduce harm. The cross-elasticities reported in this paper can be used to the advantage of public health by increasing the impact of policies that seek to drive down smoking.
However, this work does not take into account the fact that not all tobacco and nicotine products cause the same level of health harms as combustible cigarettes. The paper examines own- and cross-price elasticity across a wide array of products – from combustible tobacco products such as kreteks and little cigars to nicotine-only products such as e-cigarettes and nicotine patches – and then discusses consumption patterns in terms of an undifferentiated aggregate of nicotine use. Jawad and colleagues do not consider the health implications of policies to move nicotine users from more-harmful to less-harmful means of administration (see, for example, Chaloupka, Warner and Sweanor, 2015, recommending differential taxation according to differential risk).
From a public health perspective, any analysis of nicotine-use patterns should consider differential harm levels. A focus on nicotine use as the sole outcome variable can be seriously misleading and detrimental to the goal of reducing smoking....
NOT PEER REVIEWED The Jawad et al systematic review and meta-analysis examining price effects for non-cigarette tobacco and nicotine products appears methodologically sound and was a registered analysis. It provides information that could be used productively by advocates and policymakers seeking to reduce harm. The cross-elasticities reported in this paper can be used to the advantage of public health by increasing the impact of policies that seek to drive down smoking.
However, this work does not take into account the fact that not all tobacco and nicotine products cause the same level of health harms as combustible cigarettes. The paper examines own- and cross-price elasticity across a wide array of products – from combustible tobacco products such as kreteks and little cigars to nicotine-only products such as e-cigarettes and nicotine patches – and then discusses consumption patterns in terms of an undifferentiated aggregate of nicotine use. Jawad and colleagues do not consider the health implications of policies to move nicotine users from more-harmful to less-harmful means of administration (see, for example, Chaloupka, Warner and Sweanor, 2015, recommending differential taxation according to differential risk).
From a public health perspective, any analysis of nicotine-use patterns should consider differential harm levels. A focus on nicotine use as the sole outcome variable can be seriously misleading and detrimental to the goal of reducing smoking.
Cited Reference
Chaloupka, FJ, Sweanor D, Warner KE. Differential taxes for differential risks—toward reduced harm from nicotine-yielding products. N Engl J Med 2015 Aug 13;373(7): 594-7.
NOT PEER REVIEWED
This paper’s core findings are quite helpful: (1) Tax/price increases for non-cigarette tobacco products can effectively reduce their use; and (2) Tax/price increases for non-cigarette tobacco products could prompt some users to increase their cigarette smoking if comparable tax/price increases for cigarettes are not done at the same time. But the paper’s related analysis is incomplete, producing misleading conclusions, largely because the paper focuses on cigarettes versus non-cigarette tobacco products without also considering the more important distinction for health-directed tobacco tax strategies between smoked tobacco products and non-combustible tobacco products.
In its abstract, the paper concludes that the “positive substitutability between cigarettes and non-cigarette tobacco products suggest that tax and price increases need to be simultaneous and comparable across all tobacco products.” But the paper does not appear to consider that the only substitutions that could significantly increase public health harms would be if the tax increases prompted some non-combusted tobacco product users to move to more-harmful smoking or prompted some smokers who would otherwise do so not to move to less-harmful non-combusted tobacco products. As a result, the paper fails to acknowledge that significant tax/price increases for only combusted tobacco products would not prompt any harm-increasing substitution and would directly secure desirable...
NOT PEER REVIEWED
This paper’s core findings are quite helpful: (1) Tax/price increases for non-cigarette tobacco products can effectively reduce their use; and (2) Tax/price increases for non-cigarette tobacco products could prompt some users to increase their cigarette smoking if comparable tax/price increases for cigarettes are not done at the same time. But the paper’s related analysis is incomplete, producing misleading conclusions, largely because the paper focuses on cigarettes versus non-cigarette tobacco products without also considering the more important distinction for health-directed tobacco tax strategies between smoked tobacco products and non-combustible tobacco products.
In its abstract, the paper concludes that the “positive substitutability between cigarettes and non-cigarette tobacco products suggest that tax and price increases need to be simultaneous and comparable across all tobacco products.” But the paper does not appear to consider that the only substitutions that could significantly increase public health harms would be if the tax increases prompted some non-combusted tobacco product users to move to more-harmful smoking or prompted some smokers who would otherwise do so not to move to less-harmful non-combusted tobacco products. As a result, the paper fails to acknowledge that significant tax/price increases for only combusted tobacco products would not prompt any harm-increasing substitution and would directly secure desirable public health gains by directly reducing smoking. It would be foolish for the public health community to reject or not support such a tax increase because it did not also increase taxes on non-combustible tobacco products. But the paper suggests otherwise.
A tobacco tax increase on cigarettes and all other combustibles would secure even larger public health gains if it also used different sized tax increases on different combustible products in order to raise the prices of all smoked tobacco products to the same level as cigarettes (typically the most highly taxed tobacco products), thereby making it more likely that cigarette smokers would respond to the tax increases by cutting back their smoking or quitting altogether, rather than by switching to less-taxed and less-expensive smoked tobacco products, such as little cigars or RYO. But the paper does not consider this option, and its support for comparable tax increases for all tobacco products argues against it.
A tax increase for combusted tobacco products could secure even larger public health gains if it also increased non-combustible tobacco product taxes and prices. But only if the increases to the combusted and non-combusted tobacco product taxes did not make the non-combustibles significantly more expensive relative to cigarettes and other smoked tobacco products, either relatively or in real terms, that they dampened moves from smoking to e-cigarettes or other non-combustibles or prompted some non-combustible users to increase their smoking. But that, also, is not discussed in the paper.
Instead, the main text of the paper talks about taxes to produce equal price increases for each type of tobacco product and concludes by offering the overly broad and potentially misleading recommendation that countries with tobacco-diverse markets “should raise taxes on non-cigarette tobacco products to prevent premature death.”
Perhaps all the additional policy analysis suggested here is too much to expect from a study with the rather simple stated objective of just systematically reviewing the price elasticity of demand of non-cigarette tobacco products. But the paper goes well beyond providing that information and also encourages tax increases for non-cigarette tobacco products, either on their own or along with comparable increases for cigarettes. Given that the paper has decided to make policy recommendations, it should do so more thoughtfully, with more explanation and more detailed guidance.
NOT PEER REVIEWED
Berry et al (1) report an analysis of two waves of the Population Assessment of Tobacco and Health (PATH) study focused on the association between the initiation of e-cigarette use by Wave 2 and cigarette abstinence/reduction assessed at Wave 2. They conclude that daily e-cigarette use is associated with both cigarette abstinence and reduced consumption among continuing smokers. While this addresses an important question, we argue that such analyses should be adjusted for the reason e-cigarettes are being used.
From Wave 1 of PATH (2), we know that ~75% of smokers agreed that e-cigarettes were useful to help people quit. However, ~80% agreed that e-cigarettes allowed someone to replace a cigarette where smoking was prohibited. From the first reason, we can hypothesize that e-cigarette use might be associated with cigarette abstinence/reduction. However, from the second reason, we can also hypothesize that e-cigarettes would be associated with neither cigarette abstinence nor reduction. The recent National Academies report (3) recommended that any assessment of the role of e-cigarettes in cigarette cessation/reduction should focus on smokers who used e-cigarettes to help them quit.
Show MorePATH Wave 2 data does include information on whether smokers tried to quit in the previous year, as well as whether they used e-cigarettes to aid the last quit attempt. Previous research (4) has shown that over half of the smoking population will not ha...
NOT PEER REVIEWED
Coleman et al’s important report [1] on transitions in the vaping and smoking status of a nationally representative cohort of American 18+ adults who use electronic cigarettes (EC) from the PATH study provides rich data that can greatly advance our understanding of the natural history of EC use and their potential in harm reduction.
However, we were struck by the absence of emphasis in the report of what is perhaps its most important finding. If we examine the report’s data and consider the net impact of vaping on the critical goals of having vapers stopping smoking and vaping non-smokers not starting to smoke, the findings are very disturbing and should strong reason for pause among those advocating e-cigarettes as a game-changing way of stopping smoking.
At Wave 2, 12 months on from Wave 1, of the cohort of 2036 dual users (EC + smoking) only 104 (5.1%) had transitioned to using only EC and another 143 (7%) had quit both EC and smoking for a combined total of 247 or 12.1%. Of the 896 exclusive EC users at Wave 1, 277 (30.9%) had stopped vaping at Wave 2. Together, 524 out of the 2932 EC users (17.9%) followed from Wave 1 might be considered to have had positive outcomes at Wave 2.
The other side of the coin however, shows that of the 2036 dual users at Wave 1, 886 (43.5%) relapsed to using cigarettes exclusively. In addition, among the 896 exclusive EC users from Wave 1, 109 (12.2%) had stopped vaping and were now smoking, wit...
Show MoreNOT PEER REVIEWED
The paper by Filippidis et al [1] provides data re-confirming the well-known fact that most ex-smokers attempt to quit without using any form of assistance, whether pharmaceutical, professional or via e-cigarettes. Moreover, the proportion of ex-smokers trying to quit unaided increased substantially in Europe between 2012-17 (ex-smokers using no assistance increased from 73.9% to 80.7%), a period where e-cigarette use accelerated in some nations.
Regrettably however, this study does not permit any comparison of success rates by method, as no data are reported on which method of cessation (assisted v unassisted) was used by ex-smokers on their last, final (and so successful) quit attempt.
The authors report that those “who successfully quit reported much lower use of cessation assistance compared with smokers who had tried to quit without success” and suggest that this might reflect indication bias, whereby those who find it harder to quit self-select to use assistance, leaving the low hanging fruit of non- or less addicted smokers to fall off the smoking tree using their own determination.
While this will be true for some, there are many former heavy smokers who quit without assistance. This argument also borrows assumptions from the discredited hardening hypothesis [2], which holds, in the face of evidence to the contrary, that as smoking prevalence falls the concentration of hardened, more deeply addicted smokers increase...
Show MoreNOT PEER REVIEWED
Feliu et al’s conclusion “in the European Union countries with the higher scores in the Tobacco Control Scale, which indicates higher tobacco control efforts, have lower prevalence of smokers, higher quit ratios and higher relative decreases in their prevalence rates of smokers.” deserved comment.
First, it seems a tautology. Tobacco control policies are robustly evidence based. Accordingly, more efforts, less smokers.
Second, a PubMed search with “"tobacco control scale" only retrieved 27 articles since 2006 and no validation published yet. Obviously, the Scale poorly correlated with smoking rate: r2 being .58 in 2002/3, .15 in 2006/7 and .06 in 2010/11.(From table 3 in 2; n= 11 European countries).
Third, why make simple stuff complex? This surrogate is complex to calculate and its items are subjective because issuing a decree is useless if no implementation were enforced. In contrast, the smoking rate and its evolution are simple and reliable! How France can be ranked 4th among 28 countries with a 57/100 score (1) while smoking prevalence has been plateauing for so long at more than 30%? In France, from 2004 to 2017 no relevant increase in tobacco taxes, no implementation of the legal smoking ban in cafés or of the ban of sale to minors despite sting operations by NGO showing evidence of serious breaches.(3)
Fourth, claiming “the European Union should continue implementing comprehensive tobacco control pol...
Show MoreNOT PEER REVIEWED
The reporting of the results of this study is far from complete, which is concerning given the highly politicised controversy that surrounds this product. I hope the authors should respond to this comment by publishing supplementary material with all the data they collected in a an accessible form such a CSV file and summarised in tables in a supplementary memo.
In particular, the authors should provide all data on the following:
+ Vaping and JUUL current use (used in past 30-days) prevalence stratified by age, clearly differentiating between 18 and over and under-18s
+ Frequency of use of vaping products and JUUL within the 30 days among current (past-30 days) users, ideally using the same frequency breakdown used in the National Youth Tobacco Survey
+ Breakdown of vaping status by smoking status and frequency of vaping and JUUL use - to help determine the extent to which regular JUUL use is concentrated among smokers
+ Smoking prevalence and frequency
There is a rare opportunity to gain insights into a live controversy, yet the reporting of the survey is so incomplete it is difficult to draw any serious conclusions from it about the overall effect. For example, JUUL maybe displacing other vaping products used by youth as it is in the market overall. JUUL may be functioning as an alternative to smoking in both adolescents and adults and contributing to achieving smoke-free public health objectives.
T...
Show MoreNOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
Show MoreHowever, we have demonstrated unambiguously the a...
NOT PEER REVIEWED
The potential presence of formaldehyde cyanohydrin in the polylactic acid (PLA) filter of Marlboro Heatstick when heated was reported by Davis and al. PLA is a biodegradable thermoplastic derived from renewable resources such as corn starch. This tentative identification is based on the GC-MS analysis of the headspace of a heated piece of PLA, and the subsequent compound identification by mass spectra matching (acceptance criteria >85%) with the spectra library of the National Institute of Standard and Technology (NIST). However, this was not confirmed by injecting a purchased analytical grade reference standard, in order to unambiguously prove the presence of formaldehyde cyanohydrin. Therefore, we decided to repeat the experiment using headspace injection gas chromatography coupled to high resolution mass spectrometry under similar conditions as described in the publication. Our headspace GC-HR-MS analyses showed four peaks, at retention times of 16.38, 16.47, 17.14, and 18.58 min, in good agreement with the reported data reported (figure 4).
From the analysis of reference standards, we have confirmed the presence of both e-caprolactone (CAS# 502-44-3) and (S,S)-lactide (CAS# 4511-42-6) eluting at 16.47 and 17.14 min, respectively. We identified triacetin (CAS# 102-76-1) at 18.58 min, based on the reference standard, instead of 1,2-diacetin (their EI mass spectra are very similar).
Show MoreHowever, we have demonstrated unambiguously the a...
NOT PEER REVIEWED
In view of the rising prevalence of adolescent smoking worldwide, it makes a lot of sense to strictly limit cigarette sales only to alcohol licensed premises, particularly, in countries where there are minimum age requirements for buying alcohol. In a previous letter (1) to Lancet Global Health we had argued in favor of the same as we believe that restricting sale of cigarettes or other tobacco products will bring about a decrease in consumption by adolescents.
Smoking addictions are usually acquired during adolescence and this usually happens due to an apparently unregulated sale of tobacco products. Regulation is difficult when the number of tobacco selling establishments far exceeds the managing capacity of local administration. In India, adolescents have unrestricted access to tobacco products as small vendors, whose only source of income is by selling tobacco products, tend not to compromise on any business opportunity.
Although there is a positive association between alcohol and smoking, as the authors have pointed out “tobacco sales are not financially important for the majority of alcohol-licensed tobacco retailers”, so it is a win-win situation for preventing initiation of cigarette smoking by adolescents as alcohol vendors will have no incentive to bypass regulations by selling tobacco products to those who do not qualify as per legal age restrictions. In India, smoking and consumption of alcohol are also social taboos and th...
Show MoreNOT PEER REVIEWED The Jawad et al systematic review and meta-analysis examining price effects for non-cigarette tobacco and nicotine products appears methodologically sound and was a registered analysis. It provides information that could be used productively by advocates and policymakers seeking to reduce harm. The cross-elasticities reported in this paper can be used to the advantage of public health by increasing the impact of policies that seek to drive down smoking.
However, this work does not take into account the fact that not all tobacco and nicotine products cause the same level of health harms as combustible cigarettes. The paper examines own- and cross-price elasticity across a wide array of products – from combustible tobacco products such as kreteks and little cigars to nicotine-only products such as e-cigarettes and nicotine patches – and then discusses consumption patterns in terms of an undifferentiated aggregate of nicotine use. Jawad and colleagues do not consider the health implications of policies to move nicotine users from more-harmful to less-harmful means of administration (see, for example, Chaloupka, Warner and Sweanor, 2015, recommending differential taxation according to differential risk).
From a public health perspective, any analysis of nicotine-use patterns should consider differential harm levels. A focus on nicotine use as the sole outcome variable can be seriously misleading and detrimental to the goal of reducing smoking....
Show MoreNOT PEER REVIEWED
This paper’s core findings are quite helpful: (1) Tax/price increases for non-cigarette tobacco products can effectively reduce their use; and (2) Tax/price increases for non-cigarette tobacco products could prompt some users to increase their cigarette smoking if comparable tax/price increases for cigarettes are not done at the same time. But the paper’s related analysis is incomplete, producing misleading conclusions, largely because the paper focuses on cigarettes versus non-cigarette tobacco products without also considering the more important distinction for health-directed tobacco tax strategies between smoked tobacco products and non-combustible tobacco products.
In its abstract, the paper concludes that the “positive substitutability between cigarettes and non-cigarette tobacco products suggest that tax and price increases need to be simultaneous and comparable across all tobacco products.” But the paper does not appear to consider that the only substitutions that could significantly increase public health harms would be if the tax increases prompted some non-combusted tobacco product users to move to more-harmful smoking or prompted some smokers who would otherwise do so not to move to less-harmful non-combusted tobacco products. As a result, the paper fails to acknowledge that significant tax/price increases for only combusted tobacco products would not prompt any harm-increasing substitution and would directly secure desirable...
Show MorePages