JAMA Research Letter Over-Reported Teen E-Cigarette Quit Attempts & Over-Prescribed a Remedy

 

The Journal of the American Medical Association in March published a research letter summarizing “Failed Attempts to Quit Combustible Cigarettes and e-Cigarettes Among US Adolescents.”  The two-page missive included a call for FDA action: “The contribution of e-cigarettes to unsuccessful nicotine quit attempts among adolescents is substantial and warrants consideration as the US formulates policies to regulate e-cigarettes.”

The authors studied nationally representative samples of 8^th, 10^th and 12^th graders in the annual Monitoring the Future study (MTF) from 1997 to 2020.  For all years, students were asked if they had ever smoked a cigarette; those who did were then asked, “Have you ever tried to stop smoking cigarettes and found that you could not?”  In recent years, the MTF asked students if they had ever vaped nicotine; only in 2020 were they asked, “Have you ever tried to stop vaping nicotine and found that you could not?” 

I examined the 2020 data, since that was the focus of the research letter and a related University of Michigan press release.  The letter provided only a brief description of methods and analytic strategy.  So I requested additional information from the authors, and I used it to analyze the data underlying the letter’s findings.

The letter’s lead author was Richard Miech of the University of Michigan, a recognized expert on the Monitoring the Future (MTF) survey. 

The authors focused on unsuccessful attempts to quit cigarettes and e-cigarettes, but the group whose data they analyze is peculiar: all students who had ever used those products in their lifetime.  That includes a wide spectrum of students, from those who took a single puff at a party, to those who were using the products daily. 

I wanted to find out more about ever-users of these products.  Using the standard definition of past-30-day for current use among teens, I studied other survey questions to classify survey participants in the following table.  Note that more than a quarter (n=837) of e-cigarette ever users were not asked about current use.

Table 1. Cigarette and E-Cigarette Users in the 2020 MTF
Use	Cigarettes (n)	E-Cigarettes (n)
Ever	1,191	3,050
Current	256	1,134
Non-current	932	1,079
Never	7,874	6,015
Missing/not asked	3	837
All	9,065	9,065

  

The table raises an important question about the research: Why ask the 1,079 non-current ever users if they tried to quit vaping but couldn’t?  It doesn’t matter if they answered yes or no.  The fact that they had not used the products in the last month makes the question and the answers irrelevant.

Now let’s look at the 1,134 current e-cigarette users in greater detail.  First, how frequently did they use e-cigarettes:

Table 2. Trys/Fails Among Past Month Users of E-Cigarettes in the 2020 MTF
Past Month Use (days)	% Never Tried (n)	% Tried/Failed (n)
1-2	37% (334)	13% (30)
3-5	17% (152)	11% (25)
6-9	12% (107)	11% (24)
10-19	15% (142)	16% (35)
20-29	10% (91)	27% (60)
30	9% (86)	22% (48)
All	100% (912)	100% (222)

 

It makes sense that nearly half of the users who tried and failed to quit had used them 20+ days in the past month.  In contrast, more than half (54%) of users who never tried to quit had used e-cigarettes five times or fewer.

The numbers in red represent the 285 frequent e-cigarette users (20+ days) who are most at risk of being or becoming addicted to nicotine.  The following table contains some additional characteristics of these students:

 

Table 3. Characteristics of Frequent (20+ Day) Current E-Cigarette Users (n=285), 2020 MTF
Characteristic	Percentage
Ever smoked	55%
Ever drank alcohol	90%
Current alcohol	69%
Ever used marijuana	86%
Current marijuana	60%

 

This demonstrates that frequent e-cigarette users in the 2020 MTF were also risk-takers, half of whom smoked, and most of whom drank alcohol and used marijuana.

Miech and colleagues found that “at least 1 unsuccessful quit attempt was reported by…365 respondents for e-cigarettes in 2020,” which they opined is “substantial and warrants consideration as the US formulates policies to regulate e-cigarettes.”  However, they did not report that 39% (n=143) of the failed attempts were among teens who were not current e-cigarette users.  Of the 222 current users who had made an attempt but failed, 108 used the products 20+ days in the past month (Table 2).  This number, which is only 30% of that reported by Miech et al., represents a more valid estimate of truly unsuccessful quit attempters.

Of the 1,134 current vapers in the survey, only one-quarter (n=285) were frequent and at risk for nicotine addiction.  However, over half of them had smoked cigarettes, the vast majority were ever users of alcohol and marijuana, and strong majorities were current users of those drugs (Table 3).

Although research letters can provide valuable preliminary results, they are not a substitute for a full analysis, and they should not form the basis of government policy prescriptions.

 

Teen E-Cigarette Use & Smoking: Correlation, Not Causation

Here we go again.  Researchers funded by the National Institutes of Health issued a release saying that “teens who use e-cigarettes were more likely to transition to smokeable tobacco products. However, researchers cautioned that additional studies are needed to determine whether the association is causal.”  Their study appeared in JAMA (here).  

It may sound like the authors are denying a gateway claim, but lead author Adam Leventhal pushed the envelope in the press release: “E-cigarettes may be drawing a new generation of teens into recreational nicotine use because they are high-tech, can be purchased somewhat easily, come in enticing flavors and have a perception that they’re not harmful…If you enjoy the experience of inhaling nicotine in e-cigarettes, it makes sense that you would be open to trying other nicotine products, like cigarettes, hookah, and cigars.”

The media, naturally, saw the study as evidence that e-cigarettes are a “gateway” to smoking among teenagers.  This is a misrepresentation of the data. 

The researchers collected baseline information on “ever” lifetime use of e-cigarettes.  The 6- and 12-month follow-up outcomes were “any” use (even a few puffs) of several combustible tobacco products in the past 6 months.  It is unsurprising that the results revealed that “ever” use of e-cigarettes at baseline was associated with combustible use at follow-up.  It is well known that use of one tobacco product is associated with use of other products among teenagers, especially when the comparison group is composed of kids who have never used any tobacco product.

The bottom line: If you have “ever” used one tobacco product, you are likely to have “ever” used another.  That is correlation, not causation.  This phenomenon was also confirmed by information in Table 2 of the publication, which crosstabs students’ combustible tobacco use with their use of e-cigs at baseline.  Here are the results:

Number of Combustible Products Ever Used	Number of Students	Number (%) Ever Using E-Cigs
0	2,558	225 (9%)
1	401	156 (39%)
2	233	136 (58%)
3	134	100 (75%)

Among the 2,558 students who never smoked, e-cigs were only used by 8.8%.  Among students who had smoked one product, e-cig use was 39%.  Students using 2 and 3 products had e-cig usage rates of 58% and 75%, respectively.

This study shows that students who have “ever” used one tobacco product are likely to have “ever” used another, and that includes e-cigarettes.