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• Letter to the Editor
  Menfil A. Orellana-Barrios, Drew Payne and Kenneth Nugent
  Published on: 8 March 2017

• Published on: 8 March 2017

  Letter to the Editor

  • Menfil A. Orellana-Barrios, Physician: Internal Medicine - Cardiology University of Florida, Jacksonville
  • Other Contributors:
    • Drew Payne, Physician: Internal Medicine
    • Kenneth Nugent, Physician: Critical Care - Pulmonary

  Dear Editor:

  We commend El Dib and colleagues(1) on their extensive review effort and offer the following critiques:

  a. In their analysis regarding ENDS vs. ENNDS for smoking cessation (Figure 5)(1), the authors have chosen to compare the 6-month cessation rate for the ASCEND(2) study with the 12-month cessation rate in the ECLAT(3) study. Using equal time frames seem like it would allow a more homogenous comparison, particularly because this is available from the ECLAT publication. This does raise the bigger issue that an important conclusion in review related to e-cigarette and smoking cessation should be advocating for uniformity in outcome reporting, as has been proposed in prior publications (e.g. the Russel Standard)(4).

  b. We disagree with the author's main analysis where subjects lost to follow-up (LFU) excluded. It is incorrect to assume that the cessation rate in the LFU group is the same as the subject who actually completed the study. Regardless of this, the authors have indeed performed a "worse case" analysis but here we find discrepancy between the published cessation data from the studies and the numbers used in the analysis. Using an intention-to-treat (ITT) analysis, for instance, the ASCEND trial reported a cessation rate for ENDS of 21/289 (30/289 including non-verified) while in ECLAT this was 22/200. This is in contrast to 25/289 and 34/200, respectively, as used in the author's analysis. In the ENNDS subg...

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  Dear Editor:

  We commend El Dib and colleagues(1) on their extensive review effort and offer the following critiques:

  a. In their analysis regarding ENDS vs. ENNDS for smoking cessation (Figure 5)(1), the authors have chosen to compare the 6-month cessation rate for the ASCEND(2) study with the 12-month cessation rate in the ECLAT(3) study. Using equal time frames seem like it would allow a more homogenous comparison, particularly because this is available from the ECLAT publication. This does raise the bigger issue that an important conclusion in review related to e-cigarette and smoking cessation should be advocating for uniformity in outcome reporting, as has been proposed in prior publications (e.g. the Russel Standard)(4).

  b. We disagree with the author's main analysis where subjects lost to follow-up (LFU) excluded. It is incorrect to assume that the cessation rate in the LFU group is the same as the subject who actually completed the study. Regardless of this, the authors have indeed performed a "worse case" analysis but here we find discrepancy between the published cessation data from the studies and the numbers used in the analysis. Using an intention-to-treat (ITT) analysis, for instance, the ASCEND trial reported a cessation rate for ENDS of 21/289 (30/289 including non-verified) while in ECLAT this was 22/200. This is in contrast to 25/289 and 34/200, respectively, as used in the author's analysis. In the ENNDS subgroup, we found discrepancy as the ASCEND trial reported a rate of 3/73 (4/73 including non-verified), in contrast to the 6/73 used in the meta-analysis. The ECLAT ENNDS cessation rate was published as 5/100 (6-months) and 4/100 (12-month), versus the utilized 14/100 rate.

  c. Using the aforementioned published verified cessation rates for both ASCEND (2 e-cig arms) and ECLAT, our calculations of pooled Mantel-Haenszel risk ratio (random effects model) provide an RR= 2.02 (95% CI 0.97-4.21), p=0.06, which can lead to a very different discussion than that presented by the authors.

  d. It is important to emphasize that the analysis of ENDS vs. ENNDS really only provides insight into the role of nicotine, not e-cigarettes, in smoking cessation. Adequate trials comparing ENDS vs. other methods are needed to address the important clinical question: Are e-cigarettes useful to help patients quit regular cigarette use? To our knowledge, only the ASCEND trial and the non-randomized trial by Hajek et al.(5) have been published in this regard. Analysis of these two sets of data is difficult as only 1-month data is available for the latter.

  As clinicians, we should strive for patients to be abstinent from both regular cigarettes and e-cigarettes. However, the potential role of limited e-cigarette dosing for smoking cessation is unclear and inappropriate analysis of data can further confuse the clinician looking for answers.

  Very truly yours,

  Orellana -Barrios MA, MD
  Payne D, DO
  Nugent K, MD

  REFERENCES

  1. El Dib, Regina, et al. "Electronic nicotine delivery systems and/or electronic non-nicotine delivery systems for tobacco smoking cessation or reduction: A systematic review and meta-analysis." BMJ Open 7.2 (2017): e012680.

  2. Bullen, Christopher, et al. "Electronic cigarettes for smoking cessation: a randomised controlled trial." The Lancet 382.9905 (2013): 1629-1637.

  3. Caponnetto, Pasquale, et al. "EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as tobacco cigarettes substitute: a prospective 12-month randomized control design study." PloS one 8.6 (2013): e66317.

  4. West, Robert, et al. "Outcome criteria in smoking cessation trials: proposal for a common standard." Addiction 100.3 (2005): 299-303.

  5. Hajek, P., et al. "Adding e-cigarettes to specialist stop-smoking treatment: City of London pilot project." J Addict Res Ther 6 (2015): 2.

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  Conflict of Interest:
  None declared.

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