The latest addition to a flood of biased, federally-funded e-cigarette research is a JAMA Pediatrics article (here) claiming that e-cig use leads to smoking among teens and young adults.
First author Dr. Brian Primack (University of Pittsburgh) and colleagues analyzed a Dartmouth-based survey of 16-26 year olds. As a baseline, they asked never smokers if they had “ever” used an e-cigarette; 16 said yes and 678 said no.
A year later, Dr. Primack asked: “If one of your friends offered you a cigarette, would you try it?” and “Do you think you will smoke a cigarette sometime in the next year?” Possible answers for both questions were “Definitely yes, probably yes, probably not or definitely not.” Participants were at risk for smoking if they gave any of the first three answers – including probably not (see my blog post about probably not meaning yes). Primack also asked if participants had “smoked at least1 puff of a cigarette in her or his lifetime.” He did not ask about current smoking (in the past 30 days). Of 16 people who had ever used an e-cig at baseline, five were “at risk” for smoking one year later, and six had smoked at least a puff.
As Dr. Michael Siegel observed (here), the authors’ media campaign grossly distorted their data. Their statements to the press were based on tiny numbers, distorted by “ever” e-cigarette use refashioned as “use”, and “thinking about smoking” or ever having taken a puff repositioned as “regular smoking”.
In this analysis Primack et al. claimed to include “characteristics that have been previously associated with cigarette smoking and could also be associated with e-cigarette use.” However, they omitted characteristics that they had previously claimed were important predictors of smoking: use of snus and waterpipes. Three of the authors – Primack, Samir Soneji and James Sargent – published a study earlier this year from the same survey in the same journal (here), dubiously claiming that snus use and waterpipe smoking are gateways to cigarette smoking. (As I wrote just last week, “If you have ever used one tobacco product, you are likely to have ever used another.”) This omission is inexplicable.
In addition to Dr. Siegel’s critique, the Primack claims have been questioned by a thoughtful article at FiveThirtyEight aptly entitled, “Ignore The Headlines: We Don’t Know If E-Cigs Lead Kids To Real Cigs.” We do know that omitting important information is a fatal flaw in this study.