Psychiatrist Matthew Carpenter and colleagues at the Medical University of South Carolina have published in the journal Tobacco Control (here) a quit-smoking study that was five years in the making. At its start, I opined that the work could be valuable, depending upon its design (here). The journal article, “Snus undermines quit attempts but not abstinence,” disappoints, yielding minimal useful data.
While the authors describe their work as a “nationwide clinical trial,” they actually recruited, online, smokers who didn’t want to quit; all contact with their subjects was by phone, email and post. The “treatment” group received six weeks’ worth of Camel Snus, while the control group received none; all were given behavioral counseling and an unspecified amount of money. After the treatment, “participants in both groups were given a brief prompt to quit all tobacco products, including snus if still being used. All participants were given a referral to their state quitline.”
Dr. Carpenter made quit attempts the major goal of his study, which was odd, given that he enrolled only smokers who did not want to quit. It turns out that 26% of the snus group made quit attempts, compared with 31% of the control group, a difference that was not statistically significant and therefore does not justify the title of his article. Quit attempts lasting 24 hours were significantly less frequent in the snus group (19% vs. 26%).
Quit attempts are not nearly as important as actual quitting. The number of subjects who achieved abstinence in both the snus and control groups was the same – about 6%. As I noted previously (here), when smoking is the “illness,” snus is the “treatment,” and nicotine/tobacco abstinence the “cure,” low success rates are almost guaranteed.
Still, the trial yielded some valuable data. At the end of the study, Dr. Carpenter grouped participants who were offered snus into four groups: (1) never used it, (2) tried it but didn’t use it, (3) were using it infrequently and (4) were using it frequently. He reported that, “with never users as a referent, participants who become current frequent users at the end of the sampling period were more likely to try (RR=2.24; 95% CI 1.30 to 3.86) and succeed (at any point) in quitting (RR=2.21; 95% CI1.18 to 4.13).”
Snus did help some smokers quit, even though they had to become abstinent to be counted.
Why were success rates so low? Probably the biggest factor in getting smokers to switch to snus is informing them about the huge difference in risk. The article mentions that the snus group was told that snus “might be considered safer than cigarettes.” I wrote Dr. Carpenter, asking for details, and he graciously responded by providing the script that operators followed when talking with participants. They told smokers that “some research suggests that [snus] could be safer to you [sic] than cigarette smoking.” That is a gross understatement of the facts.
The authors advise that this project was supported by a National Cancer Institute grant of $410,000, but they also acknowledge other NIH grants totaling about $14.3 million over the last three years.
Carpenter’s “caution against wide-scale unguided use of snus as an aid to cessation” is not supported by the evidence. It’s time for Congress, the public and the research community to dedicate scarce research dollars to legitimate tobacco harm reduction efforts.