Monday, February 18, 2019

Landmark Study Fails to Find Any Evidence that Vaping is a Gateway to Smoking among Youth

A landmark study, published on January 25 in the Journal of the National Cancer Institute, found no evidence that vaping is a gateway to smoking among youth. The data come from the largest, longitudinal study of youth smoking initiation -- the PATH (Population Assessment of Tobacco and Health) study -- and include two waves of observations on nearly 12,000 U.S. youth.

The surveys asked numerous questions about both vaping and smoking behavior, including the frequency of these behaviors. It also assessed numerous risk factors for smoking that can be controlled for in multivariate analyses of smoking initiation rate differences between various groups. The baseline survey was conducted in 2013/2014 and the one-year follow-up survey occurred in 2014/2015. 

The main reported finding of the study was that ever use of e-cigarettes at baseline is a risk factor for ever use of cigarettes at follow-up. This is consistent with the findings of several other studies.

The Rest of the Story

Buried deep within the article is the rather startling, but most critically relevant finding of the entire study: The investigators were unable to report a single youth out of the 12,000 in the sample who was a cigarette naive, regular vaper at baseline who progressed to become a smoker at follow-up. Why? Because the number of these youth was so small that it was impossible to accurately quantify this number.

Based on my own calculations from the data presented, out of the 12,000 youth, there were only 21 who were even past 30-day e-cigarette users at baseline (cigarette naive) who progressed even to ever smoking at follow-up. These youth reported using e-cigarettes only 1-5 days in the past 30 days at baseline, so it is not even clear that they were regular vapers. They literally could have tried an e-cigarette once 30 days earlier.

It is possible that vaping was not a gateway to smoking for any of these 21 youth, but even if it was, they represent just 0.2% of the youth population.

In addition, the study found that although ever use of e-cigarettes increased the risk of smoking initiation, recent use of e-cigarettes (within the past 30 days) did not increase the risk of smoking initiation. This finding is consistent with the hypothesis that youth who try e-cigarettes and do not particularly enjoy them such that they become regular users are the ones who are more likely to try smoking, but that youth who actually become vapers are not any more likely to subsequently try a real cigarette.

The bottom line is that despite the widespread claims that vaping is a gateway to smoking initiation among youth, the most definitive study to date of this issue fails to provide any evidence to support that contention. If anything, it provides evidence suggesting that vaping acts as a kind of diversion that can keep some youth away from cigarette smoking.

We will certainly need to await the results from future waves of the PATH study to have a clearer idea of the trajectory of youth vaping and smoking, but at the present time, I do not believe there is any evidence that vaping serves as a gateway to smoking among youth. In contrast, the evidence to date suggests that a culture of vaping is replacing, not enhancing, a culture of smoking.

Saturday, February 09, 2019

Researchers Tell Public that Vaping Causes COPD as Scientific Rigor in Tobacco Control Drops to an All-Time Low

Based on the results of a cross-sectional study showing an association between using e-cigarettes and reporting that one has ever been told they have COPD (chronic obstructive lung disease), a number of researchers have essentially concluded that vaping causes COPD, and one researcher is telling the public that use of e-cigarettes increases one's risk of COPD just like cigarettes.

The paper, published in Drug and Alcohol Dependence, reports the results of a cross-sectional study based on the 2016 Behavioral Risk Factor Surveillance System (BRFSS) survey in Hawaii. The outcome variable was reporting ever having been told that one has COPD. The main predictor variable was ever having used an e-cigarette. The key finding of the study was that: "there was a significant association of e-cigarette use with COPD among nonsmokers (AOR = 2.98, CI 1.51–5.88, p <  .01), but the association was not significant among smokers (AOR = 1.29, CI 0.94–1.77, ns.)."

The paper concludes that: "The fact that findings for respiratory symptoms occurred primarily for nonsmokers argues against several alternative interpretations of the results." In other words, the paper is essentially arguing that this is most likely a causal effect (i.e., vaping causes COPD).

The Rest of the Story

There is absolutely no way one can conclude, or even speculate, based on the results of this cross-sectional study, that vaping is a cause of chronic obstructive lung disease. Remember, we are talking here about emphysema and chronic bronchitis (that's what is meant by COPD).

To see how ridiculous such a conclusion, or even such speculation is, one needs only to look at the sample size of never smokers in the 2016 Hawaii BRFSS who were current e-cigarette users and reported having COPD. It's 13 (based on the CDC's BRFSS online analysis tool). According to the article itself, the total sample of never smokers who were current vapers was only 45. A simple bivariate online analysis of the relationship between ever use of e-cigarettes and ever diagnosis of COPD among the never smokers in the 2016 Hawaii BRFSS reveals no significant association.

If you do the same analysis using the entire 2016 BRFSS (including all states), the proportion of never smokers who report having been diagnosed with COPD is actually higher among non-vapers (2.9%) than ever vapers (2.4%).

It's not just that there are dangers with drawing causal conclusions like this from a cross-sectional study. In this case, the sample size upon which the conclusion is being drawn is so low that the analysis is not at all reliable to begin with.

The paper ignores (and does not cite a single article from) a body of literature showing that smokers with COPD who switch to electronic cigarettes experience an improvement in their symptoms.

However, the worst problem with these conclusions (and even with the speculation) is that it is biologically implausible that vaping for a few years can cause emphysema or chronic bronchitis. Since vaping did not become widely popular until about 2011, the average number of years that the vapers in the 2016 Hawaii BRFSS used e-cigarettes could not be more than about five years.

There is simply no way that you can develop COPD from vaping for five years. Even among heavy chain smokers, it takes several decades before they develop COPD. I'm not aware of more than a handful of smokers who were diagnosed with COPD (caused by smoking) before they reached the age of 40. Population-level data show that the observed increase in COPD incidence among smokers does not begin until about age 45.

Even assuming that someone did not start smoking until they reached 20, it still takes a minimum of two decades of smoking to do enough damage to the lungs that a person develops and is diagnosed with COPD. So how can you get COPD from vaping (which is even less frequent than smoking) for just a few years?

People are just not thinking. The idea that there are a substantial number of never smokers in Hawaii who have developed COPD after just a few years of vaping is absurd on its face.

This leads me to believe that there is a strong, subconscious bias among many researchers who are so determined to find an association between vaping and chronic disease that they are forgetting basic pathology.

Moreover, there have not even been anecdotal reports of nonsmokers developing COPD after a few years of vaping. And clinical studies have failed to detect any decline in lung function, as measured by spirometry, among vapers.

Furthermore, if vaping was causing COPD, we would expect to see an increase in the prevalence of COPD over the past few years, especially since vaping rates started to increase exponentially starting in about 2011. Instead, we see little if any change in COPD prevalence since 2011.

The reason this is all so disturbing to me is not simply that it shows how scientific rigor in tobacco control literature has deteriorated. It is disturbing because disseminating these scientifically unsupported claims is going to discourage many smokers from trying to quit using e-cigarettes and may even cause many former smokers to return to smoking. After all, if you can get COPD from vaping, then why not go back to the real thing?

The unsupported, sweeping, hysterical conclusions being drawn from these studies are not just scientifically poor, they are causing harm to the public's health as well.

Sunday, February 03, 2019

Having Health Insurance Increases Your Risk of a Heart Attack, and Other Cross-Sectional Study Foibles

Later this week, a research study will be presented at the International Stroke Conference in Hawaii that purports to show that vaping increases the risk of heart attacks. In a recent post, I showed that this research is fatally flawed because it violates the basic principle in epidemiology that correlation does not equal causation. The study found a correlation between using e-cigarettes and ever having had a heart attack. The authors conclude that vaping must therefore increase heart attack risk. However, the more likely explanation is the opposite: smokers who experience a heart attack are more likely to try to quit smoking and therefore more likely to use e-cigarettes.

As an exercise, I used the same data (the 2016 Behavioral Risk Factor Surveillance Survey) to show that by the same reasoning, making a quit attempt increases your risk of a heart attack.

Here are some other factors that increase your risk for a heart attack, based on the 2016 BRFSS:
  • Having health care insurance (67% increase in heart attack risk)
  • Having a health care provider (174% increase)
  • Going to the doctor annually for a routine physical exam (150% increase in risk)
  • Having ever received the pneumonia vaccine (253% increase in risk)
  • Ever having had a mammogram (52% increase in risk)
So according to anti-vaping researcher logic, obtaining health care insurance, obtaining a health care provider, going to the doctor for routine exams, getting vaccinated for pneumonia, and having a mammogram all increase your risk of a heart attack.

By the way, the same analysis reveals that compared to vaping only occasionally, you reduce your risk of a heart attack substantially if you vape every single day.

In fact, daily vapers are at lower risk of having reported a heart attack than people who never vaped!

Junk Science Exposed: New Study Purports to Show that E-Cigarettes Increase Heart Attack Risk

According to the headline of a UPI news story from last week, vaping has been linked to an increased risk of having a heart attack. This research finding was reported worldwide, including a scary headline in London's Sunday Express reading: "New research claims vaping raises risk of deadly heart attacks and strokes."

This finding is profoundly important because if e-cigarette use does indeed increase heart attack risk, then the role of vaping in harm reduction comes into serious question.

The news headline stems from a paper that is being presented this week at the American Stroke Association’s International Stroke Conference in Hawaii.

According to the news coverage, the researchers used cross-sectional data from the 2016 Behavioral Risk Factor Surveillance Survey (BRFSS) and found that ever use of e-cigarettes increased the risk of reporting ever having had a heart attack, while controlling for age, gender, body mass index, history of diabetes, and smoking status. The same was true for the risk of reporting ever had a stroke.

While the abstract itself does not appear to be publicly available, the news articles report that the study found a 59% increase in heart attack risk associated with the use of e-cigarettes. According to one article: "The American Heart Association has subsequently cautioned the public against using e-cigarettes."

The Rest of the Story

It is irresponsible to use the results of this cross-sectional study to conclude (or even suggest) that e-cigarette use increases heart attack or stroke risk. Why? Because the study only assessed the relationship between "ever" having used e-cigarettes and "ever" having had a heart attack. The study has no information on which came first. In other words, it is entirely possible (and in fact quite likely) that the majority of respondents who reported having used e-cigarettes and having had a heart attack actually suffered the heart attack first and then subsequently started using electronic cigarettes because they were desperate to quit smoking after experiencing this life-threatening event.

A similar study (this one using cross-sectional data from the National Health Interview Survey) was published in the American Journal of Preventive Medicine last year and is subject to the same fatal flaw: it is highly likely that people who experienced a heart attack began using e-cigarettes in an attempt to quit smoking.

Trying to Quit Smoking Increases Your Risk of Having a Heart Attack

Using the same methodology as these studies, I examined the relationship between trying to quit smoking and heart attack risk. I used the 2016 BRFSS and modeled the risk of having had a heart attack as a function of having tried to quit smoking (and succeeding for at least one day). I controlled for age, gender, body mass index, diabetes, and smoking status.

The results:

Making a serious quit attempt is associated with a significant increase in heart attack risk. It actually increases your heart attack risk by 41%.


Obviously, what is going on here is not that quitting smoking increases your risk of having a heart attack. Instead, what is happening is that smokers who experience a heart attack are more likely to try to quit smoking.

But the same reasoning used by researchers to conclude that vaping increases heart attack risk supports the conclusion that trying to quit smoking increases heart attack risk.

For that matter, one could show that use of asthma inhalers is associated with an increased risk of having asthma, that use of insulin is associated with an increased risk of diabetes, or that the consumption of gluten-free food increases your risk for Celiac disease (caused by gluten allergy).

For those who are curious, trying to quit smoking is associated with a 38% increase in the risk of stroke.

Clearly, physicians should warn their smoking patients not to try to quit, as quitting appears to be associated with an increased risk of heart disease and stroke.

Sadly, we don't have to recommend that physicians counsel smokers not to try to quit -- the American Lung Association is already doing that.

Saturday, February 02, 2019

Does the American Lung Association Really Hate Smokers So Much that They Discourage Quit Attempts Using E-Cigarettes Despite New Clinical Trial Evidence of their Superiority to NRT?

On Wednesday, the New England Journal of Medicine published a new study that reported the results of a one-year randomized, clinical trial in which e-cigarettes were compared to nicotine replacement therapy (NRT) to aid smoking cessation. The study was conducted in the UK, and both treatments were accompanied by behavioral counseling. The result: "The 1-year abstinence rate was 18.0% in the e-cigarette group, as compared with 9.9% in the nicotine-replacement group (relative risk, 1.83; 95% confidence interval [CI], 1.30 to 2.58)."

This is the most definitive study yet on the effectiveness of electronic cigarettes for smoking cessation. It found that one-year smoking cessation rates with e-cigarettes were nearly twice those obtained using NRT. Although one must exercise caution in generalizing the results to the U.S., this evidence pretty much blows out of the water the claim being made by some anti-nicotine advocates that vaping actually inhibits smoking cessation.

A previous clinical trial conducted in New Zealand had found that e-cigarettes were as effective as NRT for smoking cessation, but that trial used first-generation e-cigarettes that are not thought to be as effective as products currently on the market.

This is great news for smokers, as it suggests that switching to vaping is another smoking cessation option that can be added to those already available. Certainly, for smokers who try to quit but fail with other therapies--like NRT--trying e-cigarettes is a strong and viable option. It may also be appropriate at this point for physicians to encourage smokers who want to quit and are open to trying e-cigarettes to make an attempt to switch to vaping even if they have not failed with other cessation approaches.

The Rest of the Story

So here is what the American Lung Association had to say in response to the study:

"The US Food and Drug Administration has not found any e-cigarette to be safe and effective in helping smokers quit. We only support methods that are FDA approved and regulated. Switching to e-cigarettes does not mean quitting. Quitting means truly ending the addiction to nicotine, which is very difficult."

In other words, the American Lung Association is saying that despite this clinical trial demonstrating that e-cigarettes are probably much more effective than NRT for smoking cessation, they would rather smokers continue smoking than make a quit attempt using electronic cigarettes.

The American Lung Association is stating that it does not "support" the use of e-cigarettes by smokers. This means that if a smoker is not willing to try NRT or a pill, then the American Lung Association would not recommend that they try quitting with e-cigarettes as an alternative.

Not only that, but according to this statement, the American Lung Association will never support the use of e-cigarettes because it will only do so once the FDA approves vaping as a cessation method, which will not and cannot happen. The FDA cannot approve e-cigarettes for smoking cessation because they are recreational products and not drugs. No manufacturer has ever applied to the FDA for approval of a vaping product as a smoking cessation method, and it is unlikely that will happen any time soon.

What could possibly explain why a public health organization that is supposed to be committed to improving lung health would actually discourage smokers from trying to quit using e-cigarettes, especially in the light of strong clinical trial evidence of their efficacy?

The only way I can reconcile this is to question whether subconsciously, the American Lung Association has so much hatred for smoking and smokers that they would actually prefer that a smoker continue to smoke and get sick from that smoking if they are not willing to use an FDA-approved pharmaceutical product. This is, after all, exactly what the organization is expressing. And although the reasoning behind this position is clearly not conscious, the only reasoning that could possibly explain it is some sort of underlying hatred of smokers and a desire to punish them if they don't try to quit "the right way" -- the "right way", of course, being defined by the American Lung Association.

It is important to note that the American Lung Association had a number of alternatives to its recommendation that smokers refrain from using e-cigarettes to quit. They could have recommended that NRT or pharmacotherapy remain a first-line approach, but that those smokers who fail to quit using NRT or pharmacotherapy may want to consider trying electronic cigarettes. They could have recommended that smokers switch to e-cigarettes and then try to wean themselves off the nicotine. Instead, the American Lung Association chose to make a blanket statement urging smokers not to try to quit using e-cigarettes.

I had thought that the tobacco control movement had reached its lowest point, but I never could have imagined that it would come to this: a national tobacco control organization has told smokers that they are better off continuing to smoke than trying to quit using an electronic cigarette. I don't think we can get any lower than this.