On 2016 Jan 08, Saul Shiffman commented:
Response to Dr. Jackler’s critique of Flavor Descriptors Paper published in Nicotine and Tobacco Research (Shiffman et al., 2015)
PLEASE NOTE: We have divided our response into several consecutive posts, to deal with the length limitations imposed by PubMed, while quoting Dr. Jackler's original comments, to allow readers to better follow the conversation.
We appreciate the continuing interest in our work and relish critical commentary and suggestions. Such a dialogue will serve to advance science and thus foster the development and implementation of public health-advancing policies.
In the post below, we have replied to the criticisms of our study raised by Dr. Jackler (most of which are redundant with those raised by Drs. Popova and Glantz, see our earlier post). We note that many of Dr. Jackler's remarks are ad hominem. We believe the science should be judged on its merits, so will not comment on Dr. Jackler's imaginings about our motives, just as we will discipline ourselves to be silent about his.
Three comments about general process and principles are worth making before we address specific issues:
1) All the issues raised by Dr. Jackler were also raised by Dr. Stanton Glantz in a peer review for the journal Nicotine and Tobacco Research, and subsequently posted by Dr. Glantz on the web. (The review was conducted single-blind, but Dr. Glantz' s posted comments are all but identical to the review, which makes clear he was the reviewer.) In accord with good peer review practice, the journal editor asked us to respond, and two editors and another (anonymous) peer reviewer were satisfied that we had responded adequately to the critiques, and that they did not fundamentally undermine the scientific quality of the work. Perhaps we are seeing the beginning of an era where peer reviewers do not accept editorial and consensus judgments, but simply repeat their critique on the web.
2) Some of the comments on methodology made by Dr. Jackler suggest methods he wishes we had used, populations he wishes we had studied, and studies he wishes we had done. We do not claim that our one study answers all questions, and cannot know whether different methods might have yielded different results – and neither can Dr. Jackler . The currency of science is empirical data, not hypothetical speculation. The real test is replication and extension. If critics believe different methods or populations would yield different results, they owe it to the science to do the work to show that. It has been 12 months since our study was published – time enough for Dr. Jackler to have collected the data he believes would be more informative. Criticism is easy; data counts.
3) Much of Dr. Jackler's critique amounts to his certainty that our study must be wrong, and therefore flawed, because it contradicts what he is certain he "knows" must be true, even though the data are not there. If the results contradict his intuition or certainty, then the methods must be flawed, and the researchers biased, and unethical, to boot. Returning to point #2, intuition and subjective certainty are nice; data are better. If there are conclusions Dr. Jackler wishes to assert, let him present definitive data.
Below, we take up each of Dr. Jackler's comments, quoting from his posting:
Jackler: In comparing the relative appeal of flavored e-cigarettes to non-smoking teens versus smoking adults, the obvious hypothesis would be that flavors would be of greater attraction to the young.
Response: It is uncertain what critique of our method, analysis, or interpretation can be derived from a statement of “the obvious hypothesis,” other than “I disagree with the results, because they violate my intuition.” Intuition is good. Data are better. The "obvious hypothesis" is sometimes wrong. We note also that a previous study, often cited in support of teen interest in flavors in cigarettes (and cited in our paper; Manning et al., 2009), shows interest in flavors is seen ONLY in teens who score high on sensation-seeking, which predisposes teens to cigarette smoking. Thus, observations or intuitions about the appeal to smokers cannot be generalized to all teens, and our data on nonsmoking teens is not incompatible with existing data on smoking teens.
Jackler: In a broader context, a finding that adolescents have no preference for sweet and fruity flavors would mean that e-cigarettes somehow are a special exception to well established consumption trends throughout the food and beverage industry.
Response: Dr. Jackler's statement ignores what we demonstrated empirically in the study – that the favors tested DID appeal to teens in foods and beverages (ice cream and bottled water), using the very methods he criticizes, even while having no effect on their interest in e-cigarettes. Again, data must trump intuition and conjecture.
Jackler: The logical way to determine the differences in e-cigarette flavor preferences between adults and teens would be to compare the actual frequency of flavor use by teen and adult e-cigarette users. Rather than use a direct method, Shiffman et al. compared a small cohort of teen non-smokers with adult smokers . . . There is reason to question the validity of comparing non-smoking teens with adult smokers as they are notably unequal groups. Nationally only approximately 15% of teens smoke whereas the entire adult survey group smoked. In this survey teen smokers were systematically excluded.
Response: Certainly the suggestion of comparing actual use patterns of adults and teens would be useful, but it would answer a different question than the one we set out to answer. As we clearly stated in our paper, we focused our research on the reported interest of the flavor descriptors on the two populations we regarded as being of most interest: current nonsmoking teens (who some assert are being lured in to use of nicotine by the appealing flavor descriptors, which would be a public health concern) compared to current adult smokers (whom one would want to find e-cigarette flavors appealing, to facilitate transition away from combustion cigarettes, a transition that we and many others regard as a public health good). Dr. Jackler is right that it would be interesting to know the flavor preferences of teen smokers, and we hope he or others will do that research. However, it is not clear that attracting a teen smoker away from using deadly combustible cigarettes to using e-cigarettes is the biggest public health worry – the big concern has been whether e-cigarettes would attract teens who are NOT smoking, hence our focus on this group.
Jackler: Shiffman et al. compared a small cohort of teen non-smokers with adult smokers via a marketing survey conducted for the sponsoring e-cigarette brand (NJOY) . . . The Shiffman et al. study consisted of an online survey inquiring about interest in products of the NJOY e-cigarette brand.
Response: Unfortunately, Dr. Jackler is simply wrong; we did not attach a brand name to any of the three types of products (e-cigarettes, ice cream, and bottled water) tested nor was the sponsor of the study mentioned to respondents. In addition, Dr. Jackler characterizes our study as a "marketing survey." It was no such thing. It was conducted for research and publication. This is yet another ad hominem argument to impute motives to us, without evidence, and, more importantly, without relevance.
CONTINUED IN NEXT POST
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