LETTERS E-CIGARETTES MAY IMPAIR ABILITY TO QUIT, BUT OTHER EXPLANATIONS ARE POSSIBLE In their article,1 Al-Delaimy et al. conclude that smokers who have used electronic cigarettes (e-cigarettes) may be at increased risk for not being able to quit smoking. This conclusion is consistent with other studies—four longitudinal and one cross-sectional—already reported in a review,2 yet seems at odds with data from experimental studies demonstrating that e-cigarettes have a positive influence on quitting behavior, comparable to (and in tendency better than) that of the nicotine patch.3,4 The authors adjusted for predictors of cessation such as addiction level, intention to quit, smoking status, and demographic variables, stating that the final results were independent of these factors. Nevertheless, they acknowledge the possibility of residual confounding from unmeasured variables related to quitting successfully or the characteristics of their sample. A recognized limitation was that they did not ask smokers who quit if they tried using e-cigarettes in their last successful attempt. However, another possibility could be that the smokers willing to quit and more confident in their ability to succeed (a factor partially independent of level of
Letters to the editor referring to a recent Journal article are encouraged up to 3 months after the article's appearance. By submitting a letter to the editor, the author gives permission for its publication in the Journal. Letters should not duplicate material being published or submitted elsewhere. The editors reserve the right to edit and abridge letters and to publish responses. Text is limited to 400 words and 10 references. Submit online at www. editorialmanager.com/ajph for immediate Web posting, or at ajph.edmgr.com for later print publication. Online responses are automatically considered for print publication. Queries should be addressed to the Editor-in-Chief, Alfredo Morabia, MD, PhD, at [email protected].
nicotine addiction) simply quit without any aid, while those less confident, and therefore disadvantaged, use some aid (pharmacologic, gestural, etc.). This interpretation may explain similar paradoxical findings in a cohort study showing higher relapse rates among prior smokers using nicotine replacement therapy (NRT) to quit versus unaided, both in the prior “high dependent” and “light dependent” groups.5 What are we to do based on the state of knowledge? The mere possibility that e-cigarettes impair the ability to quit smoking, together with the unknown long-term safety and toxicity, the poisoning risks in children, and the risks of normalizing smoking behavior and of bringing to smoke nonsmokers who are attracted by the novelty, flavorings, perception of safety, etc., should lead to restrictions on e-cigarettes outside of medically assisted cessation attempts. However, the high-quality Cochrane Review4 conclusions are that there is evidence from two trials that e-cigarettes help smokers stop smoking long term compared with placebo. Although the small number of trials, low event rates and wide confidence intervals around the estimates mean that the confidence in the result is rated “low” by GRADE [Grading of Recommendations Assessment, Development, and Evaluation] standards,4(p2)
the odds are clearly in favor of efficacy, even greater than that of NRT. Therefore, provided that there are smokers not willing to use NRT or other drugs but ready to make an assisted attempt, e-cigarettes can have a role as a support to counseling for quitting, as confirmed by another trial.6 j Alberto Donzelli, MD
About the Author Alberto Donzelli is the Director of Service of Education to Appropriateness and Evidence-Based Medicine, Azienda Sanitaria Locale di Milano, Milan, Italy. Correspondence should be sent to Alberto Donzelli, via Ricordi 4—20131 Milan, Italy (e-mail: adonzelli@asl. milano.it). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted June 5, 2015. doi:10.2105/AJPH.2015.302813
November 2015, Vol 105, No. 11 | American Journal of Public Health
References 1. Al-Delaimy WK, Myers MG, Leas EC, Strong DR, and Hofstetter CR. E-cigarette use in the past and quitting behavior in the future: a population-based study. Am J Public Health. 2015: 105(6):1213---1219. 2. Grana R, Benowitz N, Glantz SA. E-cigarettes: a scientific review. Circulation. 2014;129(19):1972--1986. 3. Bullen C, Howe C, Laugesen M, et al. Electronic cigarettes for smoking cessation: a randomised controlled trial. Lancet. 2013;382(9905):1629---1637. 4. McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev. 2014;12:CD010216. 5. Alpert HR, Connolly GN, Biener L. A prospective cohort study challenging the effectiveness of populationbased medical intervention for smoking cessation. Tob Control. 2012;22(1);32---37. 6. Beatrice F, Pichini S, Graziano S, Massaro G, Pacifici R. Preliminary results after 4 months of a study on medically assisted use of the electronic cigarettes in tobacco smoking harm reduction. Tabaccologia. 2014; 3-4:31---37.
E-CIGARETTES ARE LOSING GROUND AMONG SMOKERS AND NON-SMOKERS We largely agree with the discussion points in the letter by Donzelli regarding our recent article demonstrating significantly decreased odds for smoking abstinence among smokers who ever used e-cigarettes and his caution about using e-cigarettes. However we do not agree that they can be used to replace frontline medically assisted efforts because they are not regulated products. The US Prevention Services Task force made a similar decision.1 It is rather reassuring that all observational studies, including ours, that used a powerful cohort design reached similar conclusions about e-cigarette use not predicting quitting among smokers. One of the causality guidelines by Bradford Hill is the reliability of an association across multiple studies and populations. Donzelli argues that the few experimental studies published to date found some benefit from e-cigarettes for quitting purposes. However, the Cochrane review included a significant cautionary note about the utility of e-cigarettes in quitting.2 Furthermore, it is
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LETTERS
important to differentiate the importance of “real-life” quitting behavior assessed in observational studies compared with experimental intervention studies. Observational studies sample populations in naturalistic settings and reflect real-time influence and impact of e-cigarettes compared with intervention studies that recruit smokers interested in quitting. Generally, observational studies provide a more realistic reflection of population trends than intervention studies with highly selected and motivated participants. We acknowledged that we did not ask whether smokers used e-cigarettes to quit, and we were more focused on the profile of those who used them regardless of the reason (most other studies found smokers use e-cigarettes to quit). Finally, Donzelli suggests that another potential explanation for our finding is that those who have difficulty quitting and seek assistance may be those using e-cigarettes. That point actually highlights the failure of e-cigarettes in helping smokers who are supposedly the target of the e-cigarettes and would benefit the most. Our conclusion that we should be cautious about propagating e-cigarettes is buttressed by the recently published study by Leventhal et al. in JAMA,3 which found that adolescents who tried e-cigarettes were significantly more likely to subsequently use combustion cigarettes. Thus it may be that our worst fears of e-cigarettes becoming a gateway to combustion cigarettes for adolescents are being realized, while at the same time smokers who use e-cigarettes are finding it harder to quit. It seems this is a lose-lose situation for e-cigarettes. j
Contributors W. K. Al-Delaimy drafted the letter, and M. G. Myers and D. R. Strong contributed to editing it.
References 1. Torjesn I. Evidence is insufficient to recommend e-cigarettes for quitting, US committee concludes. BMJ. 2015;350:h2488. 2. McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev. 2014;12:CD010216. 3. Leventhal AM, Strong DR, Kirkpatrick MG, et al. Association of electronic cigarette use with initiation of combustible tobacco product smoking in early adolescence. JAMA. 2015;314(7):700---707.
Wael K. Al-Delaimy, MD, PhD Mark G. Myers, PhD David R. Strong, PhD
About the Authors Wael K. Al-Delaimy, and David R. Strong are with the Department of Family Medicine and Public Health, University of California, San Diego. Mark G. Myers is with the Psychology Service, Veterans Affairs San Diego Healthcare System, and the Department of Psychiatry, University of California, San Diego. Correspondence should be sent to Wael Al-Delaimy MD PhD Professor, Division of Global Health, Department of Family Medicine and Public Health, 9500 Gilman MC 0628, La Jolla, CA 92093 (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted September 1, 2015. doi:10.2105/AJPH.2015.302896
e2 | Letters
American Journal of Public Health | November 2015, Vol 105, No. 11
Letters to the editor referring to a recent Journal article are encouraged up to 3 months after the article's appearance. By submitting a letter to the editor, the author gives permission for its publication in the Journal. Letters should not duplicate material being published or submitted elsewhere. The editors reserve the right to edit and abridge letters and to publish responses. Text is limited to 400 words and 10 references. Submit online at www. editorialmanager.com/ajph for immediate Web posting, or at ajph.edmgr.com for later print publication. Online responses are automatically considered for print publication. Queries should be addressed to the Editor-in-Chief, Alfredo Morabia, MD, PhD, at [email protected].
nicotine addiction) simply quit without any aid, while those less confident, and therefore disadvantaged, use some aid (pharmacologic, gestural, etc.). This interpretation may explain similar paradoxical findings in a cohort study showing higher relapse rates among prior smokers using nicotine replacement therapy (NRT) to quit versus unaided, both in the prior “high dependent” and “light dependent” groups.5 What are we to do based on the state of knowledge? The mere possibility that e-cigarettes impair the ability to quit smoking, together with the unknown long-term safety and toxicity, the poisoning risks in children, and the risks of normalizing smoking behavior and of bringing to smoke nonsmokers who are attracted by the novelty, flavorings, perception of safety, etc., should lead to restrictions on e-cigarettes outside of medically assisted cessation attempts. However, the high-quality Cochrane Review4 conclusions are that there is evidence from two trials that e-cigarettes help smokers stop smoking long term compared with placebo. Although the small number of trials, low event rates and wide confidence intervals around the estimates mean that the confidence in the result is rated “low” by GRADE [Grading of Recommendations Assessment, Development, and Evaluation] standards,4(p2)
the odds are clearly in favor of efficacy, even greater than that of NRT. Therefore, provided that there are smokers not willing to use NRT or other drugs but ready to make an assisted attempt, e-cigarettes can have a role as a support to counseling for quitting, as confirmed by another trial.6 j Alberto Donzelli, MD
About the Author Alberto Donzelli is the Director of Service of Education to Appropriateness and Evidence-Based Medicine, Azienda Sanitaria Locale di Milano, Milan, Italy. Correspondence should be sent to Alberto Donzelli, via Ricordi 4—20131 Milan, Italy (e-mail: adonzelli@asl. milano.it). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted June 5, 2015. doi:10.2105/AJPH.2015.302813
November 2015, Vol 105, No. 11 | American Journal of Public Health
References 1. Al-Delaimy WK, Myers MG, Leas EC, Strong DR, and Hofstetter CR. E-cigarette use in the past and quitting behavior in the future: a population-based study. Am J Public Health. 2015: 105(6):1213---1219. 2. Grana R, Benowitz N, Glantz SA. E-cigarettes: a scientific review. Circulation. 2014;129(19):1972--1986. 3. Bullen C, Howe C, Laugesen M, et al. Electronic cigarettes for smoking cessation: a randomised controlled trial. Lancet. 2013;382(9905):1629---1637. 4. McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev. 2014;12:CD010216. 5. Alpert HR, Connolly GN, Biener L. A prospective cohort study challenging the effectiveness of populationbased medical intervention for smoking cessation. Tob Control. 2012;22(1);32---37. 6. Beatrice F, Pichini S, Graziano S, Massaro G, Pacifici R. Preliminary results after 4 months of a study on medically assisted use of the electronic cigarettes in tobacco smoking harm reduction. Tabaccologia. 2014; 3-4:31---37.
E-CIGARETTES ARE LOSING GROUND AMONG SMOKERS AND NON-SMOKERS We largely agree with the discussion points in the letter by Donzelli regarding our recent article demonstrating significantly decreased odds for smoking abstinence among smokers who ever used e-cigarettes and his caution about using e-cigarettes. However we do not agree that they can be used to replace frontline medically assisted efforts because they are not regulated products. The US Prevention Services Task force made a similar decision.1 It is rather reassuring that all observational studies, including ours, that used a powerful cohort design reached similar conclusions about e-cigarette use not predicting quitting among smokers. One of the causality guidelines by Bradford Hill is the reliability of an association across multiple studies and populations. Donzelli argues that the few experimental studies published to date found some benefit from e-cigarettes for quitting purposes. However, the Cochrane review included a significant cautionary note about the utility of e-cigarettes in quitting.2 Furthermore, it is
Letters | e1
LETTERS
important to differentiate the importance of “real-life” quitting behavior assessed in observational studies compared with experimental intervention studies. Observational studies sample populations in naturalistic settings and reflect real-time influence and impact of e-cigarettes compared with intervention studies that recruit smokers interested in quitting. Generally, observational studies provide a more realistic reflection of population trends than intervention studies with highly selected and motivated participants. We acknowledged that we did not ask whether smokers used e-cigarettes to quit, and we were more focused on the profile of those who used them regardless of the reason (most other studies found smokers use e-cigarettes to quit). Finally, Donzelli suggests that another potential explanation for our finding is that those who have difficulty quitting and seek assistance may be those using e-cigarettes. That point actually highlights the failure of e-cigarettes in helping smokers who are supposedly the target of the e-cigarettes and would benefit the most. Our conclusion that we should be cautious about propagating e-cigarettes is buttressed by the recently published study by Leventhal et al. in JAMA,3 which found that adolescents who tried e-cigarettes were significantly more likely to subsequently use combustion cigarettes. Thus it may be that our worst fears of e-cigarettes becoming a gateway to combustion cigarettes for adolescents are being realized, while at the same time smokers who use e-cigarettes are finding it harder to quit. It seems this is a lose-lose situation for e-cigarettes. j
Contributors W. K. Al-Delaimy drafted the letter, and M. G. Myers and D. R. Strong contributed to editing it.
References 1. Torjesn I. Evidence is insufficient to recommend e-cigarettes for quitting, US committee concludes. BMJ. 2015;350:h2488. 2. McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev. 2014;12:CD010216. 3. Leventhal AM, Strong DR, Kirkpatrick MG, et al. Association of electronic cigarette use with initiation of combustible tobacco product smoking in early adolescence. JAMA. 2015;314(7):700---707.
Wael K. Al-Delaimy, MD, PhD Mark G. Myers, PhD David R. Strong, PhD
About the Authors Wael K. Al-Delaimy, and David R. Strong are with the Department of Family Medicine and Public Health, University of California, San Diego. Mark G. Myers is with the Psychology Service, Veterans Affairs San Diego Healthcare System, and the Department of Psychiatry, University of California, San Diego. Correspondence should be sent to Wael Al-Delaimy MD PhD Professor, Division of Global Health, Department of Family Medicine and Public Health, 9500 Gilman MC 0628, La Jolla, CA 92093 (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted September 1, 2015. doi:10.2105/AJPH.2015.302896
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American Journal of Public Health | November 2015, Vol 105, No. 11
