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Response to Comment by "glantz"
Posted by EKeller on 28 Jun 2013 at 16:36 GMT
NOTE: This posting is a response to the comment left by "glantz" on 28 Jun 2013 at 01:08 GMT. The directions for responding to a comment say click the "Respond to this Posting" link in the bottom-right corner of the window. There was no such link on the page, and a text search on page for the word "Respond" came up with "No matches found."
In his blog post "Italian e-cig study does not support the conclusion that e-cigarettes stimulate smoking cessation," Stanton Glantz states, "There are two population-based studies of the relationship between e-cigarette use and cessation: as one found no effect and the other showed e-cigarette smokers were less likely to quit."
This is the study linked to when the reader clicks the associated text "one."
Adkison SE, O'Connor RJ, Bansal-Travers M, Hyland A, Borland R, Yong HH, Cummings KM, McNeill A, Thrasher JF, Hammond D, Fong GT. Electronic nicotine delivery systems: international tobacco control four-country survey. American Journal of Preventive Medicine Volume 44, Issue 3 , Pages 207-215, March 2013. http://www.ajpmonline.org...(12)00822-7/abstract
The conclusion of the abstract reads as follows:
"Awareness of ENDS is high, especially in countries where they are legal (i.e., the U.S. and UK). Because trial was associated with nondaily smoking and a desire to quit smoking, ENDS may have the potential to serve as a cessation aid."
Clicking the link associated with the text "the other" routes to this study.
Vickerman KA, Carpenter KM, Altman T, Nash CM, Zbikowski SM. Use of Electronic Cigarettes Among State Tobacco Cessation Quitline Callers. Nicotine Tob Res. 2013 May 8. http://www.ncbi.nlm.nih.g...
The conclusion of this abstract reads as follows:
"This study offers a preliminary look at e-cigarette use among state quitline callers and is perhaps the first to describe e-cigarette use in a large group of tobacco users seeking treatment. The notable rates of e-cigarette use and use of e-cigarettes as cessation aids, even though the U.S. Food and Drug Administration has not approved e-cigarettes for this purpose, should inform policy and treatment discussions on this topic."
Concerned about misrepresentation of their article, the authors published this disclaimer.
"The recently published article by Dr. Katrina Vickerman and colleagues has been misinterpreted by many who have written about it. It was never intended to assess the effectiveness of the e-cig as a mechanism to quit. Instead the analysis was intended to gain insight into e-cig use by those who enrolled in public tobacco quitline services and were contacted seven months later to determine whether or not they were quit."
The references cited by Dr. Glantz , to use his own words, "cannot be used to support any statement about the efficacy of e-cigarettes for stimulating smoking cessation one way or the other."
Elaine Keller is President of Consumer Advocates for Smokefree Alternatives Association.
All commenters should carefully read our competing interests policy (http://www.plosone.org/st...) and declare important affiliations.
On page 213 Adkison et al state: "ENDS users stated that they used ENDS as a tool to help them quit smoking, although only 11% of current ENDS users report having quit since Wave 7. Quitting did not differ between users and non-users, chi-square (2, n=4136) = 0.442 (P=0.516).
The Results section of Vickerman et al states, "Both e-cigarette user groups were significantly less likely to be tobacco abstinent at the 7-month survey compared with participants who had never tried e-cigarettes (30-day point prevalence quit rates: 21.7% and 16.6% vs. 31.3%, p < .001)."
These results directly support the statements that I made in my comment.
Actually, Elaine Keller is quite right that the Vickerman paper has no relevance to the question of how effective electronic cigarette are for smoking cessation.
What Dr. Glantz does not reveal is that instead of estimating cessation rates among a cohort of smokers who made quit attempts using these products, the study analyzed cessation rates of a large number of smokers who had previously tried to quit using e-cigarettes but failed, and then called a quitline because they had failed and wanted to try again. Then, they compared the quit rate among these smokers to that among smokers without such a history of a failed quit attempt using electronic cigarettes.
In other words, this study did not estimate quit rates among smokers trying to quit using e-cigarettes. Instead, it estimated quit rates among many smokers who were not using e-cigarettes in their quit attempt at all!
The truth is that many of the electronic cigarette users in the study did not use electronic cigarettes in their quit attempts! According to data provided in the paper, a full 28% of the sample of electronic cigarettes did not use these products in their quit attempts.
It should be clear to readers that this study was poorly designed to investigate the efficacy of electronic cigarettes. The study systematically sampled a group of quitline callers who were unsuccessful using electronic cigarettes. These people tried and failed using electronic cigarettes. How do we know they failed? Because they wouldn’t have had to call the quitline if they weren’t still smoking. This is clearly a harder core group of smokers and it is no surprise that their cessation rates were lower after 6-months than the comparison group. The study tells us nothing about the effectiveness of electronic cigarettes, other than that they do not work for everyone.
Concerned that Dr. Glantz was misrepresenting the results of their study, the authors of the study - who are at Alere Wellbeing - publicly admitted that the study was never intended to assess the effectiveness of electronic cigarettes and that the data should not be used for this purpose.
The Alere Wellbeing blog states very clearly: "The recently published article by Dr. Katrina Vickerman and colleagues has been misinterpreted by many who have written about it. It was never intended to assess the effectiveness of the e-cig as a mechanism to quit."
Dr. Vickerman herself explained that her results do not in any way indicate that electronic cigarettes are less effective than NRT, stating: "It may be that callers who had struggled to quit in the past were more likely to try e-cigarettes as a new method to help them quit. These callers may have had a more difficult time quitting, regardless of their e-cigarette use."
Michael Siegel, MD, MPH
Department of Community Health Sciences
Boston University School of Public Health