As noted previously (
here), Drs. Karl Fagerström and Tom Eissenberg have described a continuum of
dependence among tobacco and nicotine products.
They concluded that cigarettes are the most dependence-producing
(addictive) product and that smokeless tobacco is intermediate, evidenced by
clinical trials showing that quitting cigarette smoking is more difficult than
quitting ST.
In a new study published in Nicotine & Tobacco Research
(abstract
here), I use data from the 2003 Tobacco Use Supplement of the Current Population
Survey to directly compare time to first use (TTFU) among smokers and smokeless
tobacco users in a nationally representative sample.
My collaborators in the work are Nantaporn
Plurphanswat, research economist at University of Louisville’s Brown Cancer
Center, and Karl Fagerström.
Time to the first cigarette (TTFC) after waking up in the
morning is a well-established measure of dependence among smokers – the shorter the TTFC,
the stronger the addiction. This measure
is the key component of a scale developed in the late 1970s by Dr. Fagerström, for
whom the scale is named. TTFC is
strongly correlated with abstinence and time to relapse among smokers enrolled
in cessation trials and in nationally representative samples of smokers from
four countries. A comparable measure has
been developed for smokeless tobacco use.
We examined TTFU among 10,500 white men who were daily
cigarette smokers and 1,200 who were daily smokeless tobacco users. Smokers were classified according to number
of cigarettes per day (cpd) smoked: light (1-14 cpd), moderate (15-24 cpd) and
heavy (25+). Smokeless tobacco users
were subgrouped as exclusive users or former smokers.
The results show that dependence among smokeless tobacco
users is similar to that among light smokers (1-14 cpd), 9% of whose TTFU was
less than 5 minutes, and 23% under 30 minutes.
Differences in TTFU between smokers and smokeless tobacco users can be
seen in the chart below, which is from our study.
Our findings support the Fagerström-Eissenberg hypothesis
that the dependence level of cigarettes is generally higher than that of smokeless
tobacco.
This has positive implications
for tobacco harm reduction, which is the substitution of smoke-free tobacco
products for cigarettes among smokers unwilling or unable to quit.
Switching from smoking to smokeless tobacco
use is associated with a huge reduction in health risks.
This study adds evidence that a switch to smokeless
tobacco might also increase the chances for becoming completely
tobacco-free.