Wednesday, November 16, 2016

Another Engineered Study Claims Teen Vaping Leads to Smoking

A research letter published last week in JAMA asserts that teens who used e-cigarettes became “heavy” smokers.  The research appears to have been engineered to produce that result.

The lead author is Adam Leventhal, a University of Southern California psychologist with a history of exaggerated anti-e-cigarette claims (here).  Promoting his new research, Leventhal told the media (here) his work “…is the first to show that teenagers who vape not only experiment with cigarettes, but are also more likely to become regular smokers…It is also the first time teenage vaping has been linked to heavier smoking patterns involving use of multiple cigarettes per day.”
Leventhal conducted repeat surveys of Los Angeles-area high schoolers.  A baseline survey of 10th graders was followed six months later by a second.  Critical to the outcome, Leventhal defined vapers and smokers differently, as seen in this table.

Leventhal’s Definitions and Classification of Baseline Vapers and Smokers
NeverNever vaperNon-smoker
PriorEver vaperNon-smoker
Past 30 daysCurrent vaperCurrent smoker
Infrequent1-2 days1-2 days
Frequent3+ days3+ days

Why did Leventhal use different definitions for vapers and smokers?  Why did he separate past and never vaping, but combine past and never smoking?  One possible explanation is that he wanted to record more “non-smokers” at baseline, some, perhaps many of whom, were “prior” smokers.  This allowed Leventhal to count prior smokers as vaping gateway cases to subsequent smoking. 

There are additional problems.  Leventhal labeled those smoking on three or more days in the past month as “frequent,” and those consuming two or more cigarettes on days they smoked as “heavy” smokers.  He provided no reference for these cutoffs, which help support his vaping-leads-to-smoking screed. 

For context, note that the 2014 National Youth Tobacco Survey showed that nearly half of current 10th grade smokers smoked five or fewer days in the past month, and smoked five or fewer cigarettes (on days they smoked).  These were likely weekend party smokers.  Labeling infrequent users as “frequent” or “heavy” is inappropriate. 

Leventhal’s study was supported by NIH grants to him ($3.4 million over five years) and Jonathan Samet ($15.9 million over four years). 

The number of engineered e-cigarette gateway studies is growing, and they will have a major impact on FDA regulations.  Federal grant support requires the authors to share their data (here).  With the stakes so high, independent investigators who aren’t biased against e-cigarettes will eventually obtain Leventhal’s data, and his analysis, results and interpretation will surely be investigated.    


Anonymous said...

If you use Federal money to conduct a story and manage to structure the study in such a way to produce results that are at odds with reality, wouldn't that be fraud?

Unknown said...

Claiming that vaping is a "gateway" to smoking is as absurd as the old claim that smoking marijuana led to heroin addiction. What vaping does lead to is body piercing and tattoos. I have no piercings or tattoos but since switching to vaping sixteen months ago I have this overwhelming urge to go in to a tattoo parlour and have the image of Kermit the Frog tattooed on my left buttock. Explain that vapesters!

Bill Godshall said...

Many thanks for exposing these manufactured flaws in this study.

The study also:
- falsely claimed 37% of 10th graders are vapers (inaccurately citing 2015 MTF data),
- failed to compare baseline smokers to baseline vapers,
- found 95.1% of participants reported NO cigarette smoking in past month,
- found just 2.4% of participants reported what authors defined "frequent smoking" in past month,
- found 24% of 3,084 participants (including 93% who were nonsmokers) reported “prior” vaping at baseline (i.e. prior e-cig experimenting, but no use in past month),
- found just 4.7% of participants reported what authors defined as "frequent vaping" (i.e. >2 days in past month) at baseline, and
- found just 4.3% of participants reported vaping <3 days in past month at baseline.

Ever since 2009 when 20% of US teens smoked cigarettes, vapor and vaping prohibitionists have falsely claimed e-cigarettes were gateways to cigarette smoking.

Now, Leventhal et al are touting a study finding a 5% teen smoking rate as evidence that vaping is a gateway to cigarettes.