Some people quit smoking on the first try while others have
to quit repeatedly. Using such mobile technology as hand-held computers and
smartphones, a team of researchers from Penn
State and the University of Pittsburgh
is trying to find out why.
“One thing that really stood out among the relapsers is
how their urge to smoke just never dropped, in contrast to those who were
successful in quitting for a month — their urge dropped quickly and
systematically — almost immediately upon quitting,” said Stephanie Lanza,
scientific director of The Methodology Center at Penn State. “That was
surprising to see.”
With a new statistical model to interpret data and the
ability to collect data via mobile devices, the researchers looked at how
baseline nicotine dependence and negative emotional states influenced people’s
urge to smoke while they were trying to quit.
The Centers for Disease Control found in a 2010 National
Health Interview Survey of 27,157 adults that about 52 percent of cigarette
smokers tried to quit during the year. Six percent of all smokers — who had
been smoking for two years or more — quit for at least six months. Also in
2010, the CDC reported that even though cigarette smoking is the leading cause
of preventable death and disease in the U.S., nearly one in five Americans
smokes.
The team found that those who successfully quit during the
four-week study period had a weaker association between their urge to smoke and
their ability to quit. However, those who were unable to abstain did not show
any association between their urge to smoke and their self-confidence.
Saul Shiffman, professor of psychology at the University of Pittsburgh, followed 304 long-term
cigarette smokers as they tried to quit. On average, the participants smoked
more than a pack a day for 23 years. Forty participants quit smoking for the
initial 24 hours, but subsequently relapsed. During the two weeks after
quitting, 207 participants remained relatively tobacco-free. If smokers
relapsed but smoked less than five cigarettes per day, they were considered
successful quitters in this study. The remaining 57 participants were unable to
quit for even 24 hours.
Five times randomly throughout the day, mobile devices
prompted participants to answer questions. These questions asked the smokers
about their emotional state, their urge to smoke and if they were smoking. They
rated their urge to smoke at that moment on a scale of zero to 10. Using this
data collection method, the researchers collected data from subjects in their
natural environments.
Researchers followed subjects for two weeks prior to their
attempt to quit, and for four weeks after their attempt to quit, the
researchers report online in Prevention Science.
The Penn
State team used a
flexible statistical model — a time-varying effect model — that allows the
researchers to look at more than one variable at a time. This model is a decade
old, but until now was not user-friendly. The Methodology Center
created accessible software (methodology.psu.edu/downloads/tvem)
to analyze data that vary over time.
“To me, the biggest innovation here is looking at how
something like baseline dependence is predictive of that behavior over time or
(specifically) the urge to smoke over time,” said Lanza. “It’s now
expressed as a function of time. Instead of saying ‘if you’re higher on
dependence you’re going to have a higher urge to smoke over time,’ you can now
depict how that association between baseline dependence and urge to smoke
varies with time in a very fluid and naturalistic way.”
One advantages of this model is that researchers are not
confined to changes in one dimension. Researchers can look at time in a smooth
way, viewing it as a gradual and constant variable and simultaneously view two
or more variables that can change over time, such as smoking urges and negative
affect. Lanza noted that this method could be used to look at addiction and
behavior in many other areas, such as obesity, alcohol dependence, stress and
more.
“Our goal is to work hand-in-hand with tobacco (and
other) researchers, to help them understand these really intricate processes
that are happening,” said Lanza. “We want to really understand
addiction and how to break addiction, so that interventions can be targeted and
adaptable.”
