Friday, July 13, 2018

FDA: You Can Run Models, But You Can’t Hide Facts About Smokeless Tobacco

In a recent New England Journal of Medicine article, FDA researchers went to great lengths to conceal the fact that smokeless tobacco (ST) use has an entirely negligible impact on life expectancy.

The article, “Potential Public Health Effects of Reducing Nicotine Levels in Cigarettes in the United States,” (here) by Benjamin Apelberg and colleagues, was the centerpiece of FDA Commissioner Scott Gottlieb’s March 15 announcement of a radical nicotine reduction rule for cigarettes.  Drawing from the research, an FDA press announcement (here) declared that if cigarettes were minimally- or non-addictive by 2020, approximately 5 million additional adult smokers would quit smoking within just one year; only about 1.4 percent of the U.S. adult population would smoke cigarettes by 2100, in part, because more than 33 million people would avoid becoming regular smokers; more than 134 million years of life [would be] gained among the U.S. population.

While it is entirely unclear how nicotine reduction would produce the first two results, there is a fundamental flaw in Apelberg’s model that mainly affects the third, years-of-life, claim.  Correcting for that error, the model would likely confirm that ST products are nearly risk-free.

Apelberg estimates excess deaths among smokers by linking participants from National Health Interview Surveys (NHIS, 1997-2004) to the National Death Index (NDI) through 2006.  He also estimates deaths among users of ST, but uses an entirely different dataset – smokeless users who were enrolled in 1982 in the American Cancer Society Cancer Prevention Study II.

Apelberg’s use of two data sets -- NHIS for smokers and CPS-II for ST users – violates a basic rule of modeling: all inputs should be from the same or similar sources.  NHIS should have been used for analysis of both groups.  That was the procedure, for example, when Michael Fisher and colleagues used NHIS and NDI to produce a stable estimate for all-cause mortality among smokers and ST users (here). 

Apelberg may have used CPS-II because it shows that ST users’ mortality rate was 18% higher than that of never tobacco users.  Had he used NHIS, he would have had to acknowledge that smokeless users had no significant risks, as Fisher documented only a 5% excess that was not significant (HR= 1.05, CI = 0.90 – 1.23) (here).

The FDA analysis was biased through the use of exaggerated risks from an American Cancer Society study that has never been evaluated by independent researchers (here, here and here).  In this way, the FDA hid the negligible health impact of ST use.

A letter I submitted to the New England Journal of Medicine describing the flaw was not accepted.

Tuesday, July 3, 2018

Weight Wisdom: Avoid Extremes, But Being “Over” May Have Benefits

A new CDC-released study by National Center for Health Statistics’ Dr. Katherine Flegal and colleagues (here) confirms results from her groundbreaking 2005 report (here): compared with people of normal weight (BMI = 18.5 to less than 25), those who are overweight (BMI greater than 25 but less than 30) have a lower mortality rate.  Higher mortality rates are seen with obesity (BMI greater than 30) and underweight (BMI under 18.5).    

Applying weight-based mortality rates to the U.S. population, Flegal estimated in 2005 that overweight resulted in 82,094 fewer deaths, and a significant number of excess deaths were associated with obesity, a (n = 111,909) and underweight, (n = 33,746). 

As I noted in this blog five years ago (here), Flegal’s conclusions are consistent with those of many other scientific studies. 

I have long had a professional interest in population research on weight and health. In 2004, I published the first study to show that Swedish men who quit smoking by switching to snus avoided the weight gain usually seen with smoking cessation (abstract here).  In 2015, my research group analyzed data from the National Health and Nutrition Examination Surveys to demonstrate that changes in population smoking do not contribute significantly to changes in population overweight and obesity.  (BMC Obesity article available here).

The impact of weight on life expectancy is clear: Those who are underweight or severely obese are at risk of dying prematurely, while mere overweight is associated with a lower mortality rate.

Wednesday, June 27, 2018

Vapers: Tell the FDA You’re Not Merely An Anecdote!

A year and a half ago, I blogged about government agencies ignoring federal survey data showing that 2.5 million former smokers were current vapers (here).  When FDA tobacco center director Mitch Zeller dismissed this evidence as mere “anecdotal reports,”  I argued that such data constitutes legitimate population-level evidence.

Aiming to build a fresh dataset on smokers’ success in using vapor as a quitting aid, the Vapor Technology Association (VTA) and Consumer Advocates for Smoke-Free Alternatives (CASAA) just launched a national campaign called “I Am Not An Anecdote” (here).

The groups are asking vapers to submit to the FDA detailed, sworn statements to “encourage Congress and federal regulators to reject any proposal that would ban OR limit flavored e-liquid products.” The groups note that “FDA Commissioner Scott Gottlieb has said that your ‘personal stories are important to me.’  But, he also refers to your stories of quitting cigarettes with vapor products as ‘anecdotes.’”

While individual cases are, in scientific terminology, anecdotal, their cumulative value is considerable.  Vapor is replacing combustion at dramatic rates worldwide.  My research team used 2013 FDA-funded survey data to produce a peer-reviewed report on U.S. e-cigarette use (here and here).  Our analysis showed that e-cigarettes are the most popular quit-smoking aid among American smokers and that they are the only aid more likely to make them former smokers (i.e., successful quitters) than are cold-turkey attempts (here).

FDA should give weight to published studies, even when they do not conform to visions of a tobacco-free society.  The agency should also recognize the scientific value of mass declarations of smoking cessation accomplished through vaping substitution.