1. Perceived Barriers to Smoking Cessation
Mediates Tobacco Dependence and
Withdrawal in a Primarily African
American Sample
Anika Suddath & Thomas Rutner
Department of Preventive Medicine, USC
1
2. Tobacco Related Race Disparities
African Americans are affected disproportionately
American Lung Association, 2010
Figure from NHIS data
2
3. Dependence and Withdrawal
• More heavily dependent smokers experience more
severe withdrawal symptoms
• Withdrawal Symptoms
– anger, anxiety, craving, difficulty concentrating,
hunger, impatience, and restlessness
Shiffman (1989) Psycho Pharm
Hughes et al., (1991) Arch Gen Psychiatry
3
4. Withdrawal and Cessation Success
• Severe withdrawal symptoms cause poorer cessation
success rates
• Previous cognitive mechanisms
– Depression
– Anxiety
Patten and Martin (1996) Ann Behav Med
4
5. Perceived Barriers
Internal: “feeling less in control of your moods”
External: “no encouragement or help from friends”
Addiction: “thinking of never being able to smoke again”
Perceived barriers predict smoking cessation rates
Macnee & Talsma (1995)
Nursing Research
5
6. Hypothesis
Perceived barriers to cessation act as a cognitive
pathway to mediate the relationship between
dependence and acute tobacco withdrawal
Dependence Barriers Withdrawal
6
7. Participants
249 daily smokers
• non-treatment seeking
• > 10 cig/day for past 2
years
• no use of non-cigarette
tobacco or nicotine
products
Age (SD) 47.2 (11.1)
Sex 45.6% Female
Race 90.4% African American
Cigs/day 14.9 (6.6)
Years
Smoked
27.8 (12.1)
Quit
Attempts
4.6 (9.8)
7
14. Acknowledgments
Raina D. Pang, PhD
Adam M. Leventhal, PhD
Matthew G. Kirkpatrick, PhD
Claudia Aguirre, BA
Mariel S. Bello, BS
Matthew D. Stone, BA
Health, Emotion & Addiction
Laboratory
14
15. Disclosure
Funding Sources
• National Institute on Drug
Abuse
– K01-DA040043
• American Cancer Society
– RSG-13-163-01
• Undergraduate Research
Associates Program, USC
15
Industry Funding
• N/A
Off-Label Medication Use
• N/A
Conflict of Interest Statement
• The authors report no conflicts
of interest
Editor's Notes
I’m Thomas Rutner and we’re undergraduate fellows from the University of Southern California here to present our talk on the mediational affect of Perceived Barriers to Smoking cessation from tobacco Dependence to withdrawal in African Americans.
So let’s begin.
In the 50 years since the original surgeon general report on its dangers, cigarette smoking has dropped drastically to about 20% of the adult population in the United States. However, smoking remains the leading cause of cancer and is the cause of nearly 400 thousand premature deaths annually. Many groups also remain disproportionately at risk. One of these is the African American population, which has been shown to have higher rates of lung cancer and lower successful cessation rates compared to other smoking populations. This graph comes from National Health Interview Survey which shows that African-Americans have consistently had lower successful cessation rates than both white and Hispanic populations since 1965. In addition, the population remains understudied in tobacco literature, which has led us to make this group be the focus of our study.
Given the ubiquitous information regarding the danger of smoking, many highly dependent smokers express a desire to quit, but find themselves unable to do so. Previous studies have shown that more heavily dependent smokers experience more severe withdrawal symptoms. This is problematic because withdrawal symptoms have been shown to directly correlate to smokers having greater difficulty quitting. These symptoms which we measured include anger, anxiety, craving, difficulty concentrating, hunger, impatience, and restlessness.
So as I mentioned, more severe symptoms have been shown to result in poorer cessation success, which leads a lot of study today being devoted to reducing these symptoms. The goal is that finding ways to reduce these symptoms may help the final 20% of the population quit smoking. With that in mind, our literature search showed that previous studies have considered how depression, anxiety, and other mental conditions can act as cognitive mechanisms to affect smoking cessation, but have yet to consider perceived barriers as one of these potential cognitive mechanisms.
Anika
Perceived barriers to cessation acts as a cognitive appraisal which underlies a smoker’s self confidence in quitting. It’s important to think of these barriers not as current obstacles in a smoker’s life; rather as perceived or possible obstacles which may hinder a smoker during a future cessation attempt. These obstacles fall into three distinct categories internal, external and addiction which are related to three distinct bodies of literature associated with smoking cessation. For example, if a smoker believes that feeling less in control of her mood would hinder her ability to quit, that would be an internal barrier. As an individual develops a higher dependency to tobacco, say they smoke a cigarette as soon as they wake up in the morning, with their cup of coffee, with every meal and with their friends, cigarettes become a more integral part of the smoker’s life, thus when thinking about a quit attempt a more highly dependent smoker may perceive no encouragement or help from their friends as a larger hindrance to a successful quit attempt. When compared to a less dependent smoker, let’s say someone who smokes once a week, not having that help or encouragement from their friends may not seem as big of an obstacle in their quit success. Interestingly, addiction based barriers such ast thinking of never being able to smoke again, or other pharmacological and behavioral withdrawal symptoms are some of the most commonly reported perceived barriers to quitting. Furthermore, perceived barriers have also been found to independently predict the success or relapse rate of a smoking cessation attempt.
Anika
While no study to our knowledge has investigated perceived barriers as cognitive mechanism between tobacco dependence and tobacco withdrawal, prior theory does supports this pathway. Therefore we hypothesize that perceived barriers to a cessation attempt act as a cognitive pathway to mediate the relationship between dependence and acute tobacco withdrawal
Anika
Our study includes 249 non-treatment seeking daily cigarette smokers
In order to participate the participants must have been smoking 10 cigarettes a day or more for the past two year, be 18 years or older, fluent in English in order to complete our surveys, they could not have a current DSM_IV mood disorder or non-nicotine substance dependence, they could not use be using any other tobacco or nicotine products, and our female participants could not be currently pregnant or had a child within the past 6 months.
The average age of our participants was 47 years old, about 46% were female. 90.4% were African American, our study is not comprised exclusively of African Americans because it is part of a larger ongoing study where we are collecting data for a control group comprised of European Americans, for our smoking statistics the average number of cigarettes smoked per day was 15, years smoked was 28, and lifetime quit attempts was 4.6.
Anika
In our study design, after an initial phone screening to determine their eligibility, participants were scheduled for their baseline session, which was followed by two experimental session that were randomized and counterbalanced. If a participant was in randomization scheme A they
During the baseline or initial session we measured each smoker’s dependence and perceived barriers. To assess nicotine dependence severity we used the fagerstrom test of nicotine dependence which is a well-validated and widely used measure for this purpose. The barriers to cessation scale measures the degree to which perceived barriers may hinder the smoker during a future cessation attempt. The barriers are broken down into 3 subscales internal, external and addiction, where the participants must rate whether each item would be not a barrier to large barrier in hindering them during a future quit attempt. During each of the experimental sessions we used the minnesota nicotine withdrawal scale which measures withdrawal symptoms experienced so far today on a scale from none to severe. In our dataset we used the difference score between the non-deprived and deprived sessions to model abstinence induced withdrawal symptoms
So for our statistical analysis we used Process Macro for SPSS as our mediational pathway. To do so we labeled an A path which is the path of the predictor to the mediator, in our case the from Nicotine Dependence to the Perceived Barriers, and then a B path from the mediator to the outcome while controlling for the predictor, so the Perceived Barriers to Withdrawal Symptoms. After doing this, the model determines the indirect or mediational effect by multiplying paths A and B. After running this model for all the subscales, we controlled for depression, anxiety, gender, and smoking statistics, and the only one that was significant was the BCS Addiction as a mediational pathway.
So in this graphic to display our pathways we see we do have a significant direct path, which is the predictor to the outcome, or in our case FTND to the MNWS. But we also see that we have a significant A path and B path in order to end with a significant mediational effect. When we take this indirect effect and divide it by the total effect we see, we end up with a proportion mediated by of 30.7%. And so this shows that increased nicotine dependence predicts increased perceived addiction based barriers to cessation which in turn predicts more severe withdrawal symptoms during acute abstinence.
Which leads us to our conclusion, once again, that addiction based barriers represent a significant mediator between tobacco dependence and withdrawal symptoms. By extension, this also shows that these barriers could affect a smoker’s ability to quit, which has a number of clinical implications for the future. There is potential for the use of this information in treatment programs which do not currently appraise their patients’ perceived barriers to smoking cessation. We hope that this may help the treatment programs reach the last, most treatment-resistant, group of smokers.
The scope of our current study does lead to some future directions. We’re limited in our study to only include non-treatment seeking smokers and only being able to analyze the effect of acute abstinence of about 16 hours. Both of these traits make extrapolation from our findings to the overall smoking population difficult as treatment-seeking smokers or long-term abstinence effects may report differently. A future study may be able to examine these effects in a longitudinal study to even better inform treatment programs. As a final note, we did not have enough European American participants to make any conclusions between races and further study of this population would make these comparisons possible. However, the results are still promising and provide some clarity on how perceived barriers affect quit attempts in the smoking population at large, not just African-Americans.
