Friday, April 20, 2018

FDA Is Targeting E-Cigarette Retailers, But They’re Not Teens’ Primary E-Cigarette Source

FDA Commissioner Scott Gottlieb reportedly testified at a House Appropriations subcommittee April 17 about “excessive use of e-cigarettes among youths…Gottlieb said the FDA will crack down on youths' use of e-cigarettes in the coming weeks.  ‘We are going to take some vigorous enforcement steps to try to perceive what we see is inappropriate use by youth,’ Gottlieb said, refusing to elaborate on when the action will happen.  The agency has several avenues for targeting retailers that are selling to minors.  Those include a warning letter, massive fines, or banning the retailer from selling any tobacco or e-cigarettes.”

A common theme among e-cigarette prohibitionists is that the protection of children justifies all forms of regulation.  Beyond that, the commissioner’s remarks are undercut by the fact that only a small percentage of children have tried e-cigarettes, and only a tiny fraction of those youths bought c-cigarettes from retailers.  Support for this is seen in the FDA’s Population Assessment of Tobacco and Health (PATH) survey.  The PATH youth survey collected detailed information about tobacco use from 13,628 participants age 12-17 years in 2013-2014.  Based on the survey’s sophisticated weighting formula, the figures below are estimates for 25 million teens across the U.S.

The data reveal that about 2.6 million teens had ever used an e-cigarette in 2013-14.  Of these, about 771,000 had used e-cigarettes in the past 30 days – the widely accepted definition of “current” use among youth and consistent with another federal survey of teen tobacco use (discussed here).  This means that there were far fewer current e-cig users in PATH than currently used alcohol (1.83 million) or marijuana (1.24 million), which is also consistent with other federal surveys (discussed here).

Current e-cig users were asked: “In the past 30 days, how did you usually get your own e-cigarettes/cartridges and e-liquid?”  Here are the results:

PATH Survey: How Did You Get Your E-Cigarettes?
HowNumber of teensPercentage

Someone offered me one353,70046%
Gave someone else money to buy them126,50016%
Bought them myself75,7009.9%
Asked someone to give me one73,7009.7%
Got them some other way52,5006.9%
Took them from a store or another person31,6004.1%
Bought them from another person24,7003.2%
Don’t know, refused to answer32,4004.2%


The table shows that only 10% of current teen users, about 76,000, bought e-cigarettes for themselves.  In other words, while the FDA and other government agencies pursue vaping manufacturers and retailers, the vast majority of teens get e-cigarettes from unregulated sources.  Of course, even more teens use alcohol, which is only sold to adults age 21+ years, and marijuana, the sale of which is legal to adults only in limited states.

Wednesday, April 11, 2018

Another UC San Francisco E-Cigarette Gateway Claim, Based on Tiny Numbers

Last week I called for retraction of a flawed study by University of California San Francisco’s Benjamin W. Chaffee, Shannon Lea Watkins and Stanton A. Glantz that appeared in the journal Pediatrics (here and here).  

Once again using the FDA Population Assessment of Tobacco and Health (PATH) survey, the same authors exaggerated the gateway effect of e-cigarettes, hookah and smokeless tobacco in a January JAMA Pediatrics article (here).  I criticized at that time the omission of information that would have provided context for their findings (here).  The exaggerations were amplified in the media.

In an interview with National Public Radio (here), Dr. Watkins failed to note the minuscule numbers used in her study to support the gateway claim.  I have inserted those numbers in bold in her quote, here:

“We found that kids who tried e-cigarettes [n=11] or hookah [n=8] or smokeless tobacco [n=3] or cigars [n=7] – any noncigarette tobacco product – were all twice as likely to try cigarettes a year later compared to kids who hadn’t used any of those other tobacco products [n=175].  Kids who were using two or more noncigarette products [n=15] were four times as likely to report using cigarettes a year later.” (I have confirmed these numbers in the FDA data; they are in the table below)

Dr. Watkins added the extraordinary claim that trying one tobacco product changes one’s perception of cigarettes: “Using these products might change a kid’s perception of the harm of cigarettes, and so they are perceived as less dangerous and they get used to using tobacco and so using conventional cigarettes is not so scary or ‘bad’.”

In her view, trying a tobacco product causes one to change friends: “It will expose them to different kinds of kids, maybe kids that are already using conventional cigarettes, and then they might go on to try them.”

Instead of sharing her conjecture on how e-cigarettes led 11 children to begin smoking, Dr. Watkins should have focused on the fact that 80% of the 219 new smokers [n=175] in her study had not previously used any tobacco product.

Odds Ratios And Numbers of Teens Smoking Cigarettes After One Year, According to Ever Tobacco Status at Baseline
Ever Tobacco Status- Baseline (n)Odds RatioNumber Smoking At One Year (%)

Never tobacco use (9,058)Referent175 (79.9)
E-cigarettes (255)2.1211 (5.0)
Hookah (189)2.158 (3.7)
Other combustible (114)3.087 (3.2)
Smokeless tobacco (93)1.533 (1.4)
Two or more products (200)3.8115 (6.8)

All (9,909)
219 (100)

Thursday, April 5, 2018

UC San Francisco Authors Inadvertently Validate Our Call for Retraction

In the previous post I described fatal flaws in a study by University of California San Francisco’s Benjamin W. Chaffee, Shannon Lea Watkins and Stanton A. Glantz in the journal Pediatrics (here).  Their published response (here) validates my criticism.

Chaffee et al. correctly observed that I have frequently challenged flawed research, and they kindly provided three examples of my published letters to editors of scientific and medical journals.  My professional blog is replete with fact checks of published claims by federal officials (here, here, here, here, here, here) and government-funded researchers (here, here, here, here, here, here here, here) that e-cigarettes are a gateway to teen smoking.  My criticism has extended to research published by UCSF faculty (here, here, and here)

The recent Pediatrics analysis by Chaffee et al. showed that teen e-cigarette users in the Wave 1 FDA Population Assessment of Tobacco and Health (PATH) survey had higher odds of consuming 100+ cigarettes or past 30-day smoking one year later at follow-up.  I noted that the authors ignored important information about lifetime cigarette consumption (LCC), from as little as “1 puff but never a whole cigarette” all the way to having smoked 99 cigarettes.  When my research team applied LCC data to Dr. Chaffee’s analysis, his positive results for an e-cigarette “gateway” essentially disappeared. 

In response, Chaffee et al. called our addition of the LCC information a “statistical trick.”  By using that term, it appears that they believe, incorrectly, that the LCC variable is an outcome rather than a confounding factor.  Inexplicably, they described our analysis as “akin to suggesting that a study of hypertension should adjust for confounding by systolic blood pressure.” 

In this, Chaffee et al. prove our case. 

Let’s say we are studying the effect of dietary salt consumption on development of hypertension (systolic blood pressure, bp >140 mm) after one year of follow-up among participants who were not hypertensive at baseline (that is, they had a systolic bp = 90 to 139 mm).  If someone has a baseline bp of 139 mm, it is much more likely that they will have a bp of >140 mm after one year, compared to a person who had a baseline bp of 90.  It would be negligent to blame salt for causing hypertension while completely ignoring baseline systolic bp values in this example. 

The same principle applies to Dr. Chaffee’s e-cigarette study. 

The chart below clearly illustrates the large differences in LCC that Chaffee et al. ignored between never e-cigarette users and past 30 day users or triers.

It is negligent to ignore cigarette consumption at baseline while placing all the blame for smoking one year later on e-cigarette use. 

The Chafee article must be retracted.