Wednesday, August 27, 2014

In the CDC-FDA E-Cigarette Study, “Probably Not” Is the New “Yes”

Assume that you conducted a survey in which you posed two multiple-choice questions:
“Do you think you will smoke a cigarette in the next year?”
“If one of your best friends were to offer you a cigarette, would you smoke it?”

Respondents could choose from these answers:

Definitely yes
Probably yes
Probably not
Definitely not

You’d add up the “definitely yes” and probably yes” responses to tally those intending to smoke; and you’d total the negative responses to gauge how many are unlikely to smoke.

This would be a straightforward and uncomplicated task, unless you were a CDC or FDA analyst, milking the National Youth Tobacco Survey (NYTS) for scary numbers.

On August 25, the CDC issued its latest sky-is-falling press release, suggesting that e-cigarettes are driving teenagers to smoke (here).  The release focused on a study coauthored by CDC and FDA researchers (abstract here) whose core finding was: “Among non-smoking youth who had ever used e-cigarettes, 43.9 percent said they intended to smoke conventional cigarettes within the next year, compared with 21.5 percent of those who had never used e-cigarettes.” 

To reach this conclusion, the CDC-FDA re-defined “probably not” to mean “yes, I will.”  Adolescents who answered “probably not to either of the two questions were classified as intending to smoke.

The feds used 2013 data that is not yet public, but using the 2012 NYTS I can show you how much the distorted definition matters.

This table shows the numbers of never and ever users of e-cigarettes intended to smoke, using the CDC-FDA definition (i.e., “probably not” means “yes, I will”).  The percentages in parentheses are weighted to reflect the population of the survey.

Never Users of E-cigarettes
Ever Users of E-cigarettes
No intention to smoke
13,312    (76%)
  70    (41%)
Intention to smoke
  4,360    (24%)
  80    (59%)
17,672  (100%)
150  (100%)

Using conventional definitions, I produced the chart below. Any two yes responses defined intention to smoke, any two no responses were no intention, and mixed responses were just that, mixed.  These are my results:

Never Users of E-cigarettes
Ever Users of E-cigarettes
No intention to smoke
17,103  (97%)
128  (81%)
Mixed intention
     422  (  2%)
  13  (11%)
Intention to smoke
     147  (  1%)
    9  (  8%)
17,672  (100%)
150  (100%)

This paints a completely different picture of the e-cigarette situation.  The appearance that adolescents who have ever used an e-cigarette (even one puff) might be more likely to intend to smoke is based on the responses of just nine survey participants.

Carl Phillips has extensive comments on at the CASAA blog (here) and (here).

This is not the first time that a highly questionable definition has been used to fabricate a highly speculative gateway claim (here).  I assure you that this is probably not the last bogus CDC analysis of youth e-cigarette use.

Thursday, August 21, 2014

Mouth Cancer Facts

Baseball star Curt Schilling says he has mouth cancer that was caused by chewing tobacco (here).  His announcement has generated considerable interest in mouth cancer, its frequency and causes.

What is mouth cancer?

Mouth cancer typically appears in the lining of the mouth; it may start as an ulcer or red area that is discovered in a dental or medical exam.  The phrase is often used incorrectly to include cancers of the throat.

Schilling did not disclose the location of his cancer, but he did say that he found a lump in his neck.  This indicates that the tumor had spread to a lymph node, a condition that more likely suggests a tumor of the throat, rather than the mouth. 

How common is mouth cancer?

It is very rare.  Mouth cancer occurs with higher frequency in people who have the risk factors I describe below, but it is possible for someone with no risk factors to develop this disease.  As I described previously (here), among 100,000 men age 40+ years, perhaps three or four with no risk factors will develop mouth/throat cancer each year; only one or two of those cases will be mouth cancer. 

What causes mouth cancer?

The most common cause of mouth cancer is smoking, which can increase risk 10-fold; smokers who drink alcohol have even higher odds.  Alcohol abuse raises the odds about four-fold.

Another recognized risk factor is infection with human papillomavirus (HPV), a sexually transmitted disease discussed previously (here).  HPV is considered by some experts to be a significant cause of mouth cancer, but precise estimates of risk elevation are not available.

Schilling attributes his cancer to chewing tobacco.  There are numerous studies of the risks related to smokeless tobacco (discussed here).  The odds of developing mouth cancer if you use chewing tobacco or moist snuff are about the same as if you didn’t smoke, drink or have HPV.  In other words, one or two users out of 100,000 will develop mouth cancer.   

Smoking and drinking can produce a cancer anywhere in the mouth, esophagus, voicebox and lungs.  HPV is generally linked to cancers of the throat.  In contrast, the most common location, by far, for mouth cancer in a smokeless tobacco user is at or very close to where the tobacco is placed, normally between the cheek and gum.

While rare, every case of mouth cancer is unfortunate, and potentially avoidable.  Have your dentist or physician perform a thorough head and neck exam every year.

Wednesday, August 13, 2014

North Carolina Physicians Endorse E-Cigarettes

A survey of North Carolina physicians documents that many understand the benefit of e-cigarettes and some actively recommend that their smoking patients switch.  The results were published in PLoS One by Kelly Kandra of Benedictine University and colleagues from Family Medicine at the University of North Carolina (available here).

From the published paper: “Over two-thirds (67.2%) of the physicians indicated that e-cigarettes are a helpful aid for smoking cessation, and 35.2% recommended them to their patients.  A majority (64.8%) believed that e-cigarettes lower the risk of cancer for patients who use them instead of smoking cigarettes.”

It is exceptionally good news that, despite a tsunami of misinformation about e-cigarettes from federal and state health officials and major medical societies, a majority of the state’s practicing physicians know that the devices are helping smokers quit and reducing risk exposure. 

Kandra and colleagues attempt to blunt the impact of their data, writing that “physicians should remain cautious until more data is available about recommending e-cigarettes as tobacco cessation tools in clinical practice in favor of more effective modalities.”  What are those “more effective modalities”?  Nicotine replacement therapy (with a success rate of 5%, only slightly higher than placebo), varenicline (Chantix, 7% success rate), and bupropion (5% success) (reference here).

One of the study’s authors, Dr. Adam Goldstein, declared in a press release: “Physicians may choose to use FDA approved medications rather than devices and products not approved by FDA.” 

In reality, physicians may also choose e-cigarettes after “approved medications” fail.  Doctors are well equipped to weigh the risks and the benefits of consuming nicotine in smoke-free forms, and counseling their patients accordingly.

Thursday, August 7, 2014

How Many Americans Use Smokeless Tobacco?

I recently described how the federal government is all thumbs when it tries to count how many Americans smoke (here).  Further evidence of the government’s ineptitude is seen in the fact that the National Health Interview Survey (NHIS), the CDC’s official source for smoking statistics, only measures smokeless tobacco use every five years or so.  That leaves the National Survey on Drug Use and Health (NSDUH) as the government’s only annual source of data on smokeless use.

I analyzed NSDUH data from 2012 and found that 7.1% of adult men (roughly eight million) use smokeless tobacco, and the prevalence of smokeless use among women is minuscule (about one-half of one percent).  For obvious reasons, I’ll limit this discussion to men.   

NSDUH asks participants if they use “chewing tobacco” or “snuff.”  Over two-thirds of smokeless users in the survey, about 5.5 million, said they used only snuff, 1.2 million used only chewing tobacco, and 1.4 million used both.  However, participants’ responses to questions about smokeless brands used most often suggest that NSDUH misclassified some users.  The problem stems from the fact that consumers of smokeless products often use the terms “chew” or “dip snuff” interchangeably.

The most common brands among “snuff” users were Copenhagen (29%), Skoal (26%) and Grizzly (25%).  Other than Red Seal (4%) and Kodiak (4%), no other brand registered above 2%.  It is interesting to note that Camel Snus, the first pouched product that introduced the Swedish experience to American smokers, was the preferred brand for 1.7% of snuff users.

The misclassification problem is evident because 16% of “chewing tobacco” users favored Skoal, 11% picked Grizzly and 7% listed other moist snuff brands.  Red Man (25%), Levi Garrett (10%) and Beech-Nut (5%) were the top chewing tobacco brands.

Although 35% of smokeless users in this survey never smoked and 27% are former smokers, it is a tragedy that 38% are current smokers (a figure that is consistent with my previous research (discussed here).  That percentage means that 2.8 million smokeless tobacco users don’t recognize or are ignoring the significantly greater hazards of smoking.  Any ignorance on their part may be traced to the deliberate campaign by the CDC, FDA NIH and other tobacco prohibitionists to deny Americans vital facts about the relative risks of smoking and smokeless use.  This misinformation campaign conflates risk data to damn equally all forms of tobacco. The FDA declares, (here) “Tobacco products are harmful yet widely used consumer products that are responsible for severe health problems…[including] cancer, lung disease, and heart disease, which often lead to death.” The CDC asserts, (here) “Tobacco use is the leading preventable cause of death in the United States.”

Lies of omission like these tell eight million American smokeless users: “You might as well smoke.”  That is a travesty.