Wednesday, November 24, 2010
A new study about tobacco use among Air Force recruits, before and one year after basic training, has been published in the American Journal of Public Health (abstract here). The authors include two vocal tobacco opponents, Dr. Robert C. Klesges of the University of Tennessee (Memphis) and Dr. Jon O. Ebbert of the Mayo Clinic.
Dr. Klesges looked at tobacco use among airmen (an Air Force term used for both men and women) who made up a control group in a large study combining universal forced tobacco abstinence during 6 weeks of basic training and an “intervention” consisting of tobacco prevention or cessation. The results from the large study were published in 2006 (I refer to it as Klesges I, the abstract is here; I refer to the current study as Klesges II).
Klesges classified recruits based on their tobacco habits prior to basic training (baseline): nonusers of tobacco, smokers, smokeless users and dual users. In addition, he described tobacco prohibition:
“During basic military training, there is a total tobacco ban…and the prohibition is strictly enforced. At the beginning of basic military training, airmen are searched and all tobacco products are confiscated. Tobacco products are considered ‘‘contraband’’ along with alcohol, drugs, weapons, and chewing gum. The airmen recruits are required to maintain a ‘money list’ (i.e., a list of all serial numbers for all their money), which is checked regularly by basic military training instructors. Airmen are under constant supervision, and there are no tobacco products accessible even during those rare occasions when airmen are not supervised. An honor code is established early in basic training so that if a recruit breaks the rules, fellow airmen are duty bound to report the infraction. Finally, the punishment for tobacco use during basic military training is severe. In virtually all cases, the airman is ‘recycled’ (forced to repeat some or all of basic training), a possible sanction that few airmen dare risk.”
That is serious tobacco prohibition, and perhaps Klesges et al. hoped that none of the 5,225 Air Force recruits would be using tobacco 12 months later. That didn’t happen.
Klesges reported that 11% of recruits who were nonusers at baseline were smoking 12 months afterwards. As he admitted in Klesges I, “the smoking prevention program had no impact on smoking initiation.” So airmen started smoking in large numbers despite boot-camp tobacco prohibition and prevention programs.
In Klesges II, the main focus was on the 6% of smokers at baseline who were dual users afterwards. He classified this transition as harm escalation, which is an appalling misrepresentation of reality. It is scientifically established that smokers who switch to dual use smoke fewer cigarettes and have lower health risks (described here).
Other data in Klesges II were informative. Fewer than 1% of baseline smokers were smokeless users at follow-up, but 15% of baseline smokeless users were dual users and 14% were smokers at follow-up. In addition, 42% of dual users at baseline were smokers at follow-up. Thus, the transition from smokeless to cigarettes was more common than from cigarettes to smokeless. How did this happen? This is strong evidence that tobacco users in the Air Force are not properly informed about the risks of smoking and smokeless use. Unfortunately, they are making very bad decisions based on misinformation.
A big concern with this study is that the numbers don’t add up, compared with Klesges I. That study started with 7,974 airmen, compared with only 5,225 airmen in this study. In Kleges I, there were 312 smokeless users at baseline, but in Klesges II, there were only 193 (38% fewer). In Klesges I dual use was not a tobacco category, so we have no idea how it classified those 249 airmen from Klesges II. In short, reconciliation of different numbers between Klesges I and II is impossible, which is an indicator of low quality and inconsistency.
Klesges concludes that “[harm] escalation is a possible unintended consequence of promoting smokeless tobacco as a harm reduction strategy for smokers.” He is wrong. Harm escalation is the unintended consequence of not telling smokers and smokeless users the truth about the health risks.
Wednesday, November 17, 2010
Scientists from the University of Minnesota Tobacco Use Research Center have just published the results of a clinical trial from 2006-7 showing that RJ Reynolds’ Camel Snus and Philip Morris’ Taboka (a precursor of Marlboro Snus) were viable substitutes for cigarettes. The trial was conducted by Michael Kotlyar and colleagues; the results are published in Cancer Epidemiology and Biomarkers (abstract here).
Kotlyar recruited smokers who were interested in quitting, and assigned them to use one of three products: 4 milligram nicotine gum or lozenge, Camel Snus or Taboka (participants had a choice of various flavors for each product). Participants used only 1 or two products per day during a one-week sampling period; for the next four weeks, they used the product at least 6 to 8 times daily. During week 5, participants were required to reduce consumption of the substitute; by the end of that week they had to be completely tobacco- and nicotine-free.
There were several interesting results. First, all participants in all groups had a reduction in exhaled carbon monoxide, clearly demonstrating that they smoked less than before the study. Participants in all groups had a reduction in the urine concentration of two chemicals that are considered carcinogens, abbreviated here as NNN and NNAL. The reductions were statistically significant except for NNN in Camel Snus users (p = 0.07).
Overall craving and withdrawal scores decreased over the 4 weeks in all groups, with no differences between the groups.
Continuous abstinence rates over the 4 treatment weeks varied from 33% (Taboka) to 43% (Camel Snus). Two weeks after the treatment ended, 39% of the Taboka group, 47% of the Camel Snus group and 56% of the nicotine group were not smoking, but these percentages dropped to 23%, 31% and 33% respectively after ten weeks of complete abstinence.
One possible reason for the precipitous drop in the smoke-free percentages was the insistence on abstinence after 4 weeks. If this philosophy prevails, it will guarantee that smokeless products are no more effective than pharmaceutical nicotine, which has a documented failure rate of 93% (evidence here).
There is evidence that the FDA is starting to think about offering smokers “long-term” nicotine substitution (review a symposium on the topic was held on October 26-27 here), which is a strategy I called “nicotine maintenance” in 1999 (here). I recommend that readers look at the FDA presentations, especially the one by Neal Benowitz (here). He indicates that the best information about the long-term risks of nicotine come from the epidemiologic studies of Swedish snus use.
There were other interesting aspects of the Minnesota study. The Taboka group smoked significantly more than those using nicotine or Camel Snus. It is possible that Taboka, which had very low nicotine levels, simply didn’t satisfy smokers.
A total of 1,159 smokers responded to advertisements for the study. According to the researchers, 800 “were able to be reached and were screened over the telephone,” and 429 qualified and were interested in participating. Another 212 did not show up for the orientation. The attrition didn’t stop there: 211 smokers were enrolled in the study but only 130 were randomized to one of the three groups. Just 80 participants completed the 4-week treatment period and the one-week transition to abstinence.
These numbers represent one of the biggest challenges of clinical trials, especially in the field of risky behaviors like smoking. The 80 participants who completed the study represent only 6.9% of the smokers who originally responded, so they are an especially motivated group. That has been one of the problems with quit-smoking trials: It is impossible to generalize their results because they are from a highly selected population that is not representative of smokers in general.
In the past, I have criticized the Minnesota group for publishing biased and distorted studies about smokeless tobacco (here and here). But this is a fair and balanced report of the potential for smokeless tobacco as a substitute for cigarettes.
Wednesday, November 10, 2010
The U.S. government is battling tobacco and tobacco users, based to a great extent on misinformation promulgated by the Centers for Disease Control and Prevention (CDC). The CDC bills itself as “Your Online Source for Credible Health Information,” but two recent reports clearly demonstrate that the agency is deliberately deceiving Americans about fundamental facts concerning tobacco use.
Last week, the CDC published an article in the Morbidity and Mortality Weekly Report (MMWR) about the dual use of smokeless tobacco and cigarettes among men and women in the U.S. (available here). The data was from the 2009 Behavioral Risk Factor Surveillance System (BRFSS), an on-going telephone health survey tracking U.S. health conditions and risk behaviors yearly since 1984.
The information in the CDC report was routine: Smokeless tobacco use was highest in Wyoming and West Virginia (9 percent), and lowest in California (1 percent). Smoking rates were highest in Kentucky, West Virginia and Oklahoma (about 26 percent), and lowest in Utah (10 percent), California (13 percent) and Washington (15 percent).
Still, CDC director Dr. Tom Frieden used the results to rejoin the attack, with a special focus on smokeless products: “Tobacco use is the leading preventable cause of death in this country and unfortunately smokers are also using smokeless tobacco. If you smoke, quitting is the single most important thing you can do to improve your health. Use of smokeless tobacco may keep some people from quitting tobacco altogether. We need to intensify our anti-tobacco efforts to help people quit using all forms of tobacco.”
This week, with the help of the Wall Street Journal (here), the CDC turned its attention back to cigarettes, with the claim that smoking rates stopped declining several years ago. Here’s the lead:
“Many cash-strapped U.S. states are slashing budgets for tobacco-prevention programs, raising alarms among public-health groups as the nation's progress toward getting adult smokers to quit has stalled. The adult smoking rate was 20.6% in 2009, the same as a year earlier and largely unchanged since 2004, according to the Centers for Disease Control and Prevention.”
The basis for these numbers was the 2009 National Health Interview Survey (NHIS)(available here), which reported that the prevalence of smoking has been “largely unchanged” for the past several years, at just above 20%. But what about the BRFSS (discussed above)? What does that survey say about smoking rates?
For 2004, BRFSS reported the prevalence of current smoking as 20.9%, about the same as the NHIS. But for 2009, according to BRFSS, smoking prevalence had dropped to 17.9%. That’s a whopping decline of 14% in just 5 years!
One year ago I discussed in this blog how different federal surveys report contrasting data on smoking in the U.S. (here). We now have a brilliant example of how the CDC creates a consistent anti-tobacco narrative by cherry-picking data from what are essentially conflicting datasets. The public, and government budgeting officials, would be better served by a CDC that focused on reporting and explaining the unvarnished facts, free of any social behavioral bias.
Wednesday, November 3, 2010
For many years, tobacco “experts” at the Mayo Clinic have tarnished the institution’s name by fabricating misinformation about smokeless tobacco. In a 2004 article about such tactics (available here), I noted that the Mayo website contained this irresponsible, unprofessional and demonstrably false statement: “…smokeless tobacco, also called spit tobacco, has health risks just as severe or even more severe as those associated with cigarette smoking.”
Last week, Jennifer A. Kern, a Mayo Clinic behavioral counselor and former smoker, published a quit-smoking blog entry for the official Mayo Clinic web site, in which she invented new health risks related to smokeless tobacco use (here).
Ms. Kern begins with an explicit acknowledgment that smokeless tobacco is an effective substitute for cigarettes: “Those of us who live in the north are moving into the cooler seasons…it's not uncommon to see people switching tobacco products in order to stay indoors while still getting their nicotine fix. Some folks put down cigarettes and pick up smokeless tobacco products such as chewing tobacco and snuff instead.”
Ms. Kern doesn’t like smokers switching to vastly safer smokeless products, so she tries to convince them not to do so by invoking a “just-as-harmful” theme: “Smokeless tobacco products carry carcinogens, or cancer-causing chemicals, just like cigarettes do.”
Next, Ms. Kern turns to outright fabrication: “In fact, a variety of cancers that can be caused by smokeless tobacco use include: mouth and gum, larynx (voice box), esophagus, and salivary gland, as well as non-oral cancers like pancreas, kidney and penile cancer.”
My readers know that a comprehensive meta-analysis published in 2009 found that smokeless tobacco use is not associated with cancers of the mouth and gum, larynx, esophagus, pancreas or kidney (for a full discussion, click here). But what about salivary gland and penile cancer?
For salivary gland cancer, Ms. Kern may have misread a story involving Tony Gwynn, a former major league baseball player. In early October, Gwynn was diagnosed with cancer of the parotid salivary gland (described here), and he commented that “I haven't discussed that with the doctors yet, but I'm thinking it's related to dipping.” Apparently Gwynn and Ms. Kern are unaware that no epidemiologic studies have linked smokeless tobacco use and salivary gland cancer.
Ms. Kern’s most bizarre claim is that smokeless tobacco use causes penile cancer. According to the National Cancer Institute, penile cancer is extremely rare, occurring in only 1,250 American men each year (here). Penile cancer is strongly related to human papillomavirus infections and lack of circumcision (here). Maybe Ms. Kern was referring to a 1995 report linking penile cancer and smokeless use in India (here), but Swedish and American products have not been implicated in numerous epidemiologic studies.
Someone should counsel Ms. Kern and her employer about the public health imperative of sticking to the facts.