Wednesday, November 28, 2012

Secondhand Smoke and Mirrors

As I discussed over a year ago (here), claims that smoking bans result in enormous declines in hospitalizations for heart attacks (acute myocardial infarction, AMI) are largely based on selective data from small communities.  In addition, these studies rarely control for the virtually continuous decline in heart attack incidence and mortality in the U.S. for the past 50 years. 

Yet another far-fetched claim has been published: researchers at the Mayo Clinic, led by Dr. Richard Hurt from the Nicotine Dependence Center, believe that smoking bans in 2002 and 2007 in Olmsted County, Minnesota were responsible for a whopping 33% decline in AMI incidence (abstract here).  I previously detailed misinformation about smokeless tobacco emanating from that organization (here).  Dr. Michael Siegel at Boston University has expertly critiqued the scientific credibility of this study in two blog posts (here and here).  No other commentary is necessary.

In contrast to cherry-picked data from tiny communities with no adjustment for declining AMIs, a recent study of 6 million Medicare enrollees from 387 counties in 9 states was conducted by Christopher D. Barr and colleagues at Harvard University and the University of Southern California (abstract here).  They noted that “One particularly challenging issue is to carefully estimate the effect of a ban in the context of the ongoing trend of declining cardiovascular disease morbidity and mortality. If adequate adjustment is not made for the secular trend, the estimated health effects associated with the smoking ban may be biased.”  They used the term “biased,” but “grossly exaggerated” would have been more accurate.

Barr and colleagues note that “the mean AMI rate across states dropped about 28% during the years 1999-2008.”  They show that studies claiming that a smoking ban leads to fewer AMIs must account for this declining AMI incidence.  Although some investigators have tried to make adjustment for the decline, they have assumed that it is a linear phenomenon.  Barr writes that “National data show a curvilinear decline during the years of this study,…” which is not a straight-line (or linear) trend.

Barr and colleagues concluded that “the estimated effect [of smoking bans] was attenuated to nearly zero when the assumption of linearity in the underlying trend was relaxed.”  In other words, when the effect of smoking bans was effectively adjusted for the underlying decline in AMI, “…the estimated ban effect, pooled across states, is indistinguishable from zero…”

Tuesday, November 20, 2012

Jane Brody and the New York Times: Counting Smokers Badly

Jane Brody falsely reported in her November 12 New York Times “Personal Health” column that, according to the National Survey on Drug Use and Health (NSDUH), the smoking prevalence among young adults (age 18-25 years) is 40% (here).  The error was picked up by the American Council on Science and Health (here), and the Times later posted a correction, noting that the rate is 34%. (The original number was the prevalence of all tobacco use, rather than the prevalence of smoking.)  

But is 34% the accurate figure?  Perhaps; it depends on which federal survey is used. 

Anti-tobacco forces have for years selectively used two sets of numbers based on two federal surveys in a manner that recalls the schoolyard taunt, “Are you bragging or complaining?”  When zealots brag about how regulation, legislation and litigation have driven down smoking rates, they use the CDC-supported National Health Interview Survey (NHIS).  According to the 2010 NHIS, the prevalence of smoking among young adults (18-24 years) was 20% (here).  But when they complain that smoking rates are too high, and demand more regulation, legislation and litigation, they use the NSDUH, which produces higher estimates than NHIS – in this case 34%.

Why does this matter?  Using Jane Brody’s corrected percentage from NSDUH, the number of young adult smokers (18-24 years) in the U.S. is 10,489,854; using NHIS, the number is 6,165,090. 

With respect to variability, this difference of 4.5 million smokers is huge, and here’s why. 
NSDUH estimates are higher because it counts as a smoker anyone who answers “yes” to this question: "During the past 30 days, have you smoked part or all of a cigarette?”  The comparable question in the NHIS is, "Do you now smoke cigarettes every day or some days?"  

I published a formal study of this problem in 2009 (abstract here), and I wrote a blog post about it (here).  At that time, I calculated that there were 9 million more smokers of all ages nationally in NSDUH compared with NHIS.  

How can the federal government develop effective policies to help American smokers when the government can’t even develop and employ consistent estimates of how many Americans smoke? 

I am grateful to Jane Brody for bringing attention to this egregious problem. 

Wednesday, November 14, 2012

Tobacco Trick or Treat by Florida’s Surgeon General

On Halloween, Dr. John Armstrong, Florida Surgeon General and Secretary of Health, launched an attack on flavored tobacco, ostensibly to protect children (I expressed concern three years ago about the crusade against tobacco flavors, here and here).  As I note in the attached letter, “the availability of flavored tobacco products is important for tobacco harm reduction among adults who smoke…” because “…these individuals [should] have access to appealing, vastly safer smoke-free alternatives to cigarettes.”  Furthermore, contrary to Dr. Armstrong’s claim, there is no evidence that tobacco flavoring is aimed at targeting youth.  The full text of my letter follows:

November 12, 2012

John H. Armstrong, MD, FACS
Surgeon General and Secretary of Health
State of Florida

Dear Dr. Armstrong,

I am a professor of medicine and hold an endowed chair in tobacco harm reduction research at the University of Louisville.  I read with interest an article in the St. Pete Patch entitled “Candy Flavored Tobacco: Trick or Treat” (here), which provided the following quote from you:

“Youth have always been a target for the tobacco industry, and our Department will not sit by and watch.  Companies perceive youth as an easy target, and develop products like flavored tobacco and marketing campaigns aimed at them.”

The 1998 Master Settlement Agreement (MSA) between the four largest American tobacco manufacturers and the attorneys general of 46 states (here) expressly prohibited the egregious actions you describe occurring in Florida.  Section IIIa of this agreement, titled “Prohibition on Youth Targeting”, specifies that “No participating Manufacturer may take any action, directly or indirectly, to target Youth within any Settling State in the advertising, promotion or marketing of Tobacco Products…” 

As you know, the state of Florida was not a party to the MSA.  Instead, Florida entered into an individual agreement with tobacco manufacturers (here) that appears not to have youth targeting and marketing prohibitions.  However, I believe that tobacco manufacturers have a moral obligation to follow the spirit of the MSA in Florida.   

I reviewed the Tobacco Free Florida website on candy-flavored tobacco (here), which claims that flavors include “berry, vanilla, chocolate and green apple, orange, cherry and coffee” and that tobacco products are presented in “colorful and playful packaging.”  I do not believe that this constitutes evidence that manufacturers are “directly or indirectly” targeting youth. 

The availability of flavored tobacco products is important for tobacco harm reduction among adults who smoke. From a public health standpoint, it is important that these individuals have access to appealing, vastly safer smoke-free alternatives to cigarettes.  The flavors highlighted by Tobacco Free Florida have no special appeal to youth, so there is no reason they should not be used in adult tobacco products.  Banning tobacco flavoring is no more logical than banning flavored beer, wine and mixed drinks on the grounds that those products appeal to youth.

As a state official, you have made specific allegations that tobacco manufacturers are targeting youth and have “marketing campaigns aimed at them.”   The mere use of flavoring in tobacco products does not warrant such a claim. 

I share your interest in preventing initiation of tobacco use by youth, and would appreciate your sharing with me any specific evidence of unlawful tobacco marketing to this protected class.


Brad Rodu
Endowed Chair, Tobacco Harm Reduction Research
School of Medicine
University of Louisville

Wednesday, November 7, 2012

Nicotine Levels in American Smokeless Tobacco Products

Nicotine levels in smokeless tobacco products available in the U.S. in 2006 and 2007 were analyzed by scientists at RJ Reynolds Tobacco Company (abstract here).  I previously discussed other analyses reported by the scientists, on tobacco-specific nitrosamine levels (here) and trace metals (here).

Nicotine is tobacco’s primary attraction for humans; it provides many positive effects on human behavior (reviewed here).  It is widely known that nicotine can be consumed by inhaling the smoke of burning tobacco, or by using smokeless tobacco, with differences in the efficiency and rate of absorption (here).

When using smokeless tobacco, nicotine is absorbed across the lining of the mouth.  Many factors affect this, including the physical characteristics of the product (chewing tobacco, fine cut moist snuff, powdered snuff, pouch, etc.), and how it is held in or moved around the mouth.  An important factor is the product’s pH – its acidity or alkalinity.  Nicotine cannot be absorbed efficiently in an acidic environment like that of the stomach; that’s the reason tobacco isn’t consumed like tea or coffee. 

The amount of nicotine readily available to the smokeless user can be calculated by measuring the product’s pH.  A higher pH yields more available, or “free” nicotine.  Of course, one of the roles of saliva is to buffer alkaline and acidic foods to a neutral pH, so even acidic smokeless products provide some nicotine as saliva works to neutralize their acidity.

The table reflects levels of nicotine and free nicotine in smokeless tobacco products in 2006 and 2007.  Because nicotine levels were not calculated on dry weight, dry products are not entirely comparable to products with higher moisture content.  Differences can also be seen within categories. 

In general, chewing tobacco and dry snuff had low levels of free nicotine, while levels in moist snuff products were considerably higher.

What does this mean for the smoker who switches to smoke-free products?  There are no simple answers.  Inhaling smoke provides a bolus, or spike, of nicotine within seconds of the first puff, but the small amount is metabolized quickly.  Some smokeless products are capable of delivering a similar peak level, but at a slower pace, and research shows that with smokeless products, the falloff from peak levels is much slower. 

The broad range of free nicotine levels among these products is good news for smokers.  They should look for a smokeless substitute that satisfies them.

Nicotine (mg/g) and Free Nicotine (mg/g) Levels in Smokeless Tobacco Products in the U.S., 2006 and 2007
Product NicotineFree Nicotine
Dissolvable Tobacco
Chewing Tobacco
Beech Nut7.10.02
Levi Garrett5.30.06
Red Man8.60.08
Red Man Golden7.70.06
Stoker Chew Apple3.80.01
Taylor’s Pride6.40.06
Traditional Moist Snuff
Cooper LC WG8.01.1
Copenhagen LC13.95.4
Copenhagen Pouches11.26.8
Grizzly LC WG 200610.36.6
Grizzly LC WG 200711.25.9
Husky FC12.94.8
Kayak LC WG11.92.3
Kodiak WG 200610.96.5
Kodiak WG 200710.78.2
Longhorn LC WG13.85.7
Red Seal FC13.23.1
Renegades WG13.42.4
Skoal FC Original13.33.9
Skoal LC Cherry12.71.7
Skoal LC Mint12.93.7
Skoal LC Straight13.43.9
Skoal LC WG12.82.9
Timberwolf LC WG14.15.2
Snus and Snus-Style Snuff
Camel Frost 200613.34.7
Camel Frost 200714.14.7
Camel Original 200613.94.7
Camel Original 200713.56.2
Camel Spice 200613.26.7
Camel Spice 200713.45.1
Catch Dry Eucalyptus*15.91.4
Catch Dry Licorice*16.70.7
General Portion*8.55.1
General White Portion*7.94.8
Skoal Dry11.92.4
Taboka Green13.00.5
Powdered Dry Snuff
Dental Sweet11.10.1
Levi Garrett16.60.1
Railroad Mills23.10.5
Red Seal15.10.4