Tuesday, March 31, 2015

E-Cigarette Opponent Uses Cross-Sectional Study to Conclude that E-Cigs are a Gateway to Smoking

On his blog Sunday, Stan Glantz cited a new UK study as supporting the conclusion that e-cigarettes are a gateway to smoking among youth.

The study was a cross-sectional survey of nonsmoking 10-11 year-old children in Wales. They reported on their e-cigarette use and on their intentions to smoke in the future. The study found that users of e-cigarettes were significantly more likely to have intentions to smoke.

Specifically: "Having used an e-cigarette was associated with intentions to smoke (OR=3.21; 95% CI 1.66 to 6.23). While few children reported that they would smoke in 2 years’ time, children who had used an e-cigarette were less likely to report that they definitely would not smoke tobacco in 2 years’ time and were more likely to say that they might."

From these findings, Glantz concludes: "While a cross-sectional study, susceptibility to smoking is a well-validated measure of future smoking, so the results support the gateway effect."

The Rest of the Story

Because this is a cross-sectional study, it is unable to determine the direction of causality. Which came first? The e-cigarette use or the intention to smoke?

While Glantz reports the result as e-cigarette users being more likely to have intentions to smoke, the results could just as easily presented as youth with intentions to smoke being more likely to try e-cigarettes.

Clearly, except for Stan, one cannot discern from this study whether youth who try e-cigarettes then develop an intention to smoke or whether youth with a predisposition to smoking are more likely to experiment with e-cigarettes.

That Stan draws a conclusion anyway suggests that he has come to a pre-determined conclusion and is twisting the data to support this conclusion.

However, it is entirely possible that what these results indicate is that e-cigarettes appeal much more to kids who are highly predisposed to try tobacco cigarettes. In fact, it is possible that by diverting these youth to e-cigarettes and their flavorings, e-cigarette experimentation may actually prevent youth from smoking. After all, once they try the sweet flavors of e-cigarettes, it would be extremely difficult to imagine them then transitioning to a Marlboro cigarette.

The rest of the story is that many e-cigarette opponents have drawn a pre-determined conclusion that e-cigarettes are evil and are therefore so biased that they are skewing the interpretation of scientific studies to support their pre-determined conclusions, even when the science does not support these conclusions.

This is another way of saying that ideology has taken over for science in the anti-smoking movement.

No comments: