Does vaping induce teenagers to become smokers?

Do electronic cigarettes lead users into smoking real cigarettes? In other words, is vaping a "gateway activity" to smoking?

A recent study says that, yes, vapers are indeed more likely to become smokers than non-vapers are. In fact, they're *four times* as likely to do so. 

The study looked at a sample of young people aged 16 to 26 who said they didn't intend to become smokers. When they caught up with them a year later, only 9.6 percent of the non-vapers had smoked in the past year. But 37.5 percent of the vapers had!

Seems like pretty strong evidence, right? The difference was certainly statistically significant.

Except ... here's an article from FiveThirtyEight that suggests that, no, this is NOT strong evidence that vaping leads to smoking. Why not? Because the sample size was very small. The vaping group comprised only 16 participants, compared to 678 for the control group.

Vaping:      6/ 16  (37.5%)

Non-Vaping: 65/678   (9.6%)

FiveThirtyEight says,

"Voila, six out of 16 makes 37.5 percent — it’s a big number that comes from a small number, which makes it a dubious one. 

So because six people started smoking, news reports alleged that e-cigs were a gateway to analog cigs."

Well, I have some sympathy for that argument, but ... just a little. Statistical significance does adjust for sample size, so, in effect, the data does actually say that the sample size issue isn't that big a deal. To argue that 16 people isn't enough, you need something other than a "gut feel" argument. For instance, you could hypothesize that 16 vapers out of 694 people is a lower incidence of vaping than in the general population, and, therefore, you're getting only "out of the closet vapers" self-identifying, which makes the 16 vapers unrepresentative. 

But, the article doesn't make any arguments like that.

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The FiveThirtyEight story tries to make the case that the study, and the press release describing it, are biased, because they're too overconfident about a sample that's too small to draw any conclusions. 

I don't agree with that, but I DO agree that there's bias. A much, much worse bias, one that's obvious when you think about it, but one that has nothing to do with the actual statistical techniques. 

What's the actual problem? It's that the whole premise is mistaken. Comparing vapers to non-vapers is NOT evidence for whether vaping entices young people into smoking. Not at all. Even with a huge sample size. Even if you actually counted everyone in the world, and it turned out that vapers were five times as likely to become smokers as non-vapers, that would NOT imply that vaping leads to smoking, and it would NOT imply that banning vaping would "protect our youth" from the dangers of smoking real cigarettes.

It could even be that, depsite vapers being five times as likely to take up smoking, vaping actually *reduces* the incidence of smoking.

How? Well, suppose that vapers and smokers are the same "types" of people, those who want to send a signal that they're risk-takers and nonconformists. Before, they all took up smoking. Now, some take up smoking and some vaping. Sure, some of the vapers become smokers later. But, overall, you could easily have fewer smokers than before you started. 

As Tom Tango put it:

"What do I think? A vaper is in denial. It’s not the vaping itself that causes you to become a smoker, but simply that a smoker is a closet-vaper. 

"This is likely true of most vices. It won’t act as a gateway, but simply that you will try it because you were going to try to harder stuff anyway. Even if you didn’t want to admit it. 

" ... There’s a dozen ways to get from Chinatown to Times Square. Manhattan then adds a direct bus line that goes up Broadway. Does that bus “cause” people to go from Chinatown to Times Square? Or, does it simply become a stepping stone that they would have otherwise bypassed? 

"Basically, do the same number of people end up going Chinatown to Times Square? 

"Do the same number of people end up smoking the real stuff anyway? All vaping is doing is redirecting the flow of people?"

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If that sounds too abstract in words, it'll become crystal clear if we just change the context, but leave the numbers and arguments the same.

"Ignore The Headlines: We Don’t Know If Suicide Hotlines Lead Kids to Kill Themselves.

"After a year, 37.5 percent of those who had called a Suicide Hotline had gone on to end their own lives. That's a big percentage when you consider that the suicide rate was only 9.6 percent among respondents who hadn’t called the hotline.  

"Our study identified a longitudinal association between suicide hotline use and progression to actual suicide, among adolescents and young adults. Especially considering the rapid increase and promotion of distress lines, these findings support regulations to limit suicide hotlines and decrease their appeal."

It's exactly the same thing! Really. I edited a bit, but most of the words come exactly from the original articles on vaping.

Now, you could argue: well, it's not REALLY the same thing. We know that suicide hotlines decrease suicide, but, come on, can you really believe that vaping reduces smoking?

To which I answer: absolutely. I *do* believe that vaping reduces smoking. If you believe differently, then, study the issue! This particular study doesn't provide evidence either way.

And, more importantly: "can you really believe?" is not science, no matter how incredulously you say it.

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Logically and statistically, the relevant number is NOT what percentage of vapers (hotline callers) go on to smoke (commit suicide). The relevant number is, actually, how many people would go on to smoke (commit suicide) if vaping (suicide hotlines) did not exist. 

Why is this not as obvious in the vaping case as in the hotline case? Because of bias against vaping. No other reason. The researchers and doctors start out with the prejudice that vaping is a bad thing, and, because of confirmation bias, interpret the result as, obviously, supporting their view. It seems so obvious that they don't even consider any other possibility.

I bet it's not just vaping and suicide hotlines. I suspect that we'd be eager to accept the "A leads to more bad things than non-A" if we're against A, but we see it's obviously a ridiculous argument if we approve of A. Here are a few I thought of:

"37% of teenagers who play hockey went on to commit assault, as compared to only 9% who didn't play hockey. Therefore, hockey is a gateway to violence, and we need to limit access to hockey and make it less appealing to adolescents." 

"37% of teenagers who use meth go on to commit crimes, as opposed to only 9% who didn't use meth. Therefore, meth is a gateway to criminal behavior, and we need to limit access to meth and make it less appealing to adolescents." 

"37% of patients who get chemotherapy go on to die of cancer, as opposed to only 9% of patients who don't get chemo. Therefore, chemotherapy leads to cancer, and we need to limit access to chemo and make it less appealing to oncologists." 

"37% of men who harass women at work go on to commit at least one sexual assault in the next ten years. This shows that harassment is a precursor to violence, and we need to take steps to reduce it in society."

If you're like me, in the cases of "bad" precursors -- meth and harassment and vaping -- the arguments seem to make sense. But, in the cases of "good" precursors -- hockey and chemotherapy and suicide prevention lines -- the conclusions seem obviously, laughably, wrong.

It's all just confirmation bias at work.

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The FiveThirtyEight piece references one of their other posts, titled: "Science Isn’t Broken.  It’s just a hell of a lot harder than we give it credit for."

In that piece, they give several reasons for why so many scientific findings turn out to be false. They mention poor peer review, "p-hacking" results, and failure to self-correct.

Those may all be happening, but, in my opinion, it's much less complicated than that. 

It's just bad logic. It's not as obvious as the bad logic in this case, but, a lot of the time, it's just errors in statistical reasoning that have nothing to do with confidence intervals or methodology or formal statistics. It's a misunderstanding of what a number really means, or a reversal of cause and effect, or an "evidence of absence" fallacy, or ... well, lots of other simple logical errors, like this one.

Regular readers of this blog should not be too surprised by my diagnosis here: most of the papers I've critiqued here suffer from that kind of error, the kind that's obvious only after you catch it. 

FiveThirtyEight writes:

"Science is hard — really f*cking hard."

But, no. It's *thinking straight* that's hard. It's being unbiased that's hard. It must be. There were hundreds of people involved in that vaping study -- scientists, FiveThirtyEight writers, doctors, statisticians, public policy analysts, editors, peer reviewers, anti-smoking groups -- and NONE of them, as far as I know, noticed the real problem: that the argument just doesn't make any sense.

Hat Tip: Tom Tango, who figured it out.

FDA: non-filtered cigarettes aren't any more dangerous than ultra-lights

(Warning: non-sports post)

Last month, the USA banned the use of words such as "mild" or "light" to describe cigarettes. The government claims that "light" cigarettes are no safer than regular ("full flavored") cigarettes. There are lots of reports about this on the web, such as this one from the CBC:

The U.S. Food and Drug Administration says cigarette packs no longer can feature names such as "light," "mild," "medium" or "low," which many smokers wrongly think are less harmful than "full-flavour" cigarettes.

To which I say: I don't believe the "wrongly" part. The idea that light cigarettes aren't less harmful than regular cigarettes just doesn't make sense to me.

First, consider this: if light cigarettes aren't less harmful than regular cigarettes, that implies that regular cigarettes can't be *more* harmful than light cigarettes. It's simple logic and simple mathematics. If A is not less then B, then B is not greater than A. Right?

I just can't believe that if you take a "light" cigarette, and take the filter off of it, the resulting cigarette is no more harmful than with the filter on it. Do you believe that? If you do believe it, then, if you're a smoker of light cigarettes, why not switch to the stronger, unfiltered ones? The government itself says the stronger ones aren't any worse! Apparently, you can take a light cigarette, rip off the filter, and add as much tar and other carcinogens as you want -- but still, the original light cigarette is not less dangerous than the modified one!

If it had been the cigarette companies saying that, instead of the government, the s**t would have hit the fan, wouldn't it? Imagine an ad for unfiltered cigarettes that said, "Hey, these have more tar and carcinogens than normal. But switch to these, since they're still no worse for you than normal filtered cigarettes."

Can you believe that the government, and the anti-smoking groups, would let any tobacco company get away with that? Not a chance. It would take about five seconds before lawyers started looking for people who believed the tobacco companies and decided to smoke non-light cigarettes, and then got cancer. The lawsuits would fly.

Seriously, I don't think anyone really believes that the stronger cigarettes aren't worse for you. What I think is happening is that there's a moral panic with regard to smoking, a panic that makes everyone scared to tell the truth because it's politically incorrect. In today's anti-smoking climate, the goal isn't to describe the issues impartially -- the goal is to denounce the evil. The object is to never say anything that sounds like you're condoning the moral evil. So, you can say "light cigarettes aren't better" but you can't say "regular cigarettes aren't worse" -- even though those two statements *mean exactly the same thing*. The words "aren't worse," when applied to the evil of smoking -- any kind of smoking -- sound like you're condoning the activity, and that's not allowed. Every sentence you utter has to appear to support the position that smoking is wrong and bad and evil.

Now, the anti-smokers do have some reasonable arguments about why light cigarettes aren't as "less unsafe" as they may appear. They argue that in order to get their nicotine, smokers have to puff harder on "light" cigarettes, which negates their "lightness". They say that smokers block some of the airholes in the filters of light cigarettes, and so get a stronger dose of carcinogens than stated on the label, which are measured by smoking machines in labs. And so it all evens out in the end.

It does sound like there's some truth to that ... if you don't think about it too much. If you do think about it a bit, you realize that it doesn't work for other things, does it? For instance, restaurants in New York City now have to post calorie counts for all their menu items. The idea is that customers will be scared off by high calorie counts and eat less.

If that works for food, why shouldn't it work for smoking? Why is it that it's presumed that smokers won't end their smoke break until they reach a certain nicotine dose, but not that eaters won't end their meal until they've been satisfied by a certain calorie dose? It seems to me that either the food premise or the nicotine premise must be wrong.

Even if you accept the premise that smokers measure by nicotine, that still isn't enough to justify the conclusion. Suppose it's true that smokers automatically compensate for low nicotine levels by smoking harder. All things being equal, wouldn't that make high-nicotine cigarettes safer? You might only have to smoke half a cigarette to get your nicotine fix (and nicotine itself isn't that dangerous, which is why the nicotine patch is such an improvement over smoking).

But remember the scandal when it was revealed that cigarette companies artificially boosted their cigarettes' nicotine content? By this argument, you'd think that they'd be hailed as heroes -- you could get your fix with less smoking! But, no: they were denounced. The higher nicotine levels were taken as evidence that the cigarette companies were trying to get their clients dangerously hooked.

That argument implies that higher nicotine levels are bad for smokers. Doesn't that imply that lower nicotine levels are *less* bad for smokers? Again, if A is worse than B, then B must be less bad than A.

Again, if no cigarette is any "less unsafe" than any other cigarette, then how can you criticize the cigarette companies for changing their products' recipes? Again, it seems like it's possible to make a cigarette A that's more dangerous than cigarette B, but, by some miracle that supersedes Aristotelian logic, cigarette B somehow escapes being less dangerous than cigarette A.

Besides, even if smokers do smoke light cigarettes harder, to try to maximize their nicotine, that still doesn't make them all equal. This government document (.pdf) lists tar and nicotine levels for several hundred brands and types of cigarettes. They all have different ratios. Take, for instance, the third and fourth cigarettes on the list. One is "full-flavored" (regular) with 15 tar and 0.9 nicotine. The other is "light" with 9 tar and 0.7 nicotine.

Do the arithmetic. With the regular cigarette of that brand, you can smoke one cigarette and get a 0.9 dose of nicotine with 15 tar. With the light, you can smoke 1.29 of those cigarettes, and get the same 0.9 nicotine dose with only 11.57 tar. Doesn't it seem obvious that the light cigarette gives you less tar for the same nicotine hit? Isn't less tar going to be less harmful than more tar? So isn't the light cigarette in this case indeed going to be less harmful than the regular cigarette?

It's not just tar. According to this article (and many others), there are some 4,000 compounds in cigarette smoke, many of which are harmful or carcinogenic. That is: the health risks of smoking come from the chemicals inhaled. But if cigarette A, with X micrograms of carcinogens, is no "less bad" than cigarette B, with 2X micrograms of carcinogens ... then doesn't it follow that smoking one pack of A isn't any "less bad" than smoking two packs of A? Your body only knows the dose of carcinogens -- it doesn't care how many cigarettes it took to get that way. (Otherwise, we could cure cancer by giving everyone a single two-ton cigarette to smoke over their lifetime. One cigarette won't kill you!)

In a just world, the government would lay out the exact risks from different levels of tar, nicotine, and other carcinogens, brand by brand, and let smokers choose what level of risk they're willing to tolerate. But there's a moral panic out there. Anti-smoking groups seem to believe that it's OK withhold risk information from smokers, and even lie to them, in order to avoid acknowledging that there are less risky (but still dangerous) alternatives that some smokers might prefer.

And it's all because "less harmful" sounds like it's off-message. It's like saying "rape is less harmful than murder" -- it's true, but unpalatable. It doesn't come down hard enough on rape for our taste. If you choose not to think about it, your brain might register only the words "rape" and "not" and "bad" and come to the wrong conclusion. But your discomfort, your hysterical reaction, and your failure to think about it do not make the original statement any less true.

You know what it's like? It's exactly like when some religions don't want to teach teenagers about condoms. They're happy to tell stories about how condoms don't reduce the risk of disease entirely (which is technically true), but they won't actually discuss just how much they *do* reduce the risk (a lot). They refuse to acknowledge that oral sex is safer than penetrative sex. They claim to care about preventing harm, but, when you look at their actions instead of their words, what they *really* care about is preventing sex.

Smoking is the new sex. The only politically correct policy is to promote abstinence, even if you have to lie shamelessly about the risks.