Abstract and Introduction
Aim: To assess potential barriers to clinical integration of tailored smoking cessation treatment among African American and white smokers in the USA.
Methods: A total of 392 smokers (203 white and 189 African American) identified within a national random digit dial survey (response rate: 40.1%; 81.2% among households with whom we were able to make contact) of 1200 African Americans and 1200 white Americans. Respondents answered several closed-ended survey items addressing beliefs regarding what influences a smoker's ability to quit, past pharmacotherapy use, and their willingness to undergo genetic assessment in order to be matched to optimal treatment, among other items.
Results: In this first nationally representative survey of US smokers, 77% of respondents expressed willingness to undergo genetic testing in order to be matched to optimal pharmacotherapy, yet only 18% had ever used pharmacotherapy in a previous quit attempt. Smokers who rated 'medications and counseling' as very important in quitting were significantly more likely to endorse genetic testing (odds ratio [OR]: 8.94; 95% CI: 1.86–43.06), while those rating 'having God's help' as very important were significantly less likely to express willingness to undergo testing (OR: 0.11; 95% CI: 0.02–0.71). African American smokers were more likely than white smokers to express willingness to undergo genetic testing (OR: 3.80; 95% CI: 1.09–13.22), despite lower rates of previous pharmacotherapy use.
Conclusion: While smokers reported high rates of willingness to undergo genetic testing to be matched to optimal treatment, these results suggest that smokers' willingness to use medications indicated by genetic test results may prove a significant barrier to realizing the promise of tailored smoking cessation treatment. The role of spirituality in smokers' willingness to use medication is an area for further study.
The decade following the completion of the Human Genome Project has seen important developments in pharmacogenomic (PGx) treatment strategies that promise to achieve improved outcomes by matching patients to optimal therapy based on their individual profiles. The challenges associated with translating these improved treatment strategies into clinical practice, however, are many. Understanding patients' attitudes and beliefs, and how these are likely to affect uptake of efficacious new PGx applications, will be critical to successful clinical integration and realizing subsequent health improvements. To the extent that novel treatment strategies improve quit rates, differential uptake among patient subpopulations may exacerbate existing racial/ethnic and socioeconomic disparities in smoking-related morbidity and mortality. We use the case of individualized smoking cessation to probe these issues and elucidate patient-focused challenges to translating PGx medicine into practice.
Smoking remains a leading cause of mortality, responsible for 443,000 deaths in the USA and 730,000 deaths in the EU each year,[4,5] creating a global health crisis.[6,7] Despite aggressive prevention campaigns, 19% of adults in the USA and 28% in the EU smoke. Pharmacotherapy (including nicotine replacement therapy and other medications, such as bupropion and varenicline) represents the best available cessation treatment,[10,11] but only approximately 32–35% of smokers use pharmacotherapy in a quit attempt.[12,13] Among smokers that use approved cessation medications, only approximately 25% of smokers are able to quit, perhaps due to the fact that there is up to a fivefold interindividual variability in therapeutic response.[15–17]
The need for improved smoking cessation treatment strategies has spurred research into PGx approaches to match patients to smoking cessation medications based on their individual profile, resulting in improved cessation rates.[12,18–29] One of the most promising PGx developments within smoking cessation treatment is the Nicotine Metabolite Ratio, a genetically informed biomarker that provides a stable individualized measure of the rate of nicotine clearance. Retrospective trials have shown that slower nicotine metabolizers respond well to nicotine patch therapy, while faster metabolizers will likely require a non-nicotine-based therapy (bupropion or varenicline) to succeed in quitting.[30–32] A prospective trial to validate these results is currently underway. The success of these emerging PGx smoking treatments will require that, first, smokers be willing to undergo genetic testing (e.g., provide a cheek swab) to receive tailored treatment recommendations, and, second, that they be willing to take medications indicated by test results.
Numerous studies have documented substantially lower rates of pharmacotherapy use among minority smokers,[12,20,27–29] raising questions about the impact on health disparities of PGx smoking treatment strategies, which require a willingness to use medications. If emerging PGx treatment strategies for smoking are indeed efficacious, reduced willingness to take medications among African American smokers will likely translate into ever-increasing racial disparities between smoking-related morbidity and mortality.
In this report, we provide results of the first nationally representative survey of African American and white adult smokers in the USA to assess their willingness to undergo genetic testing in order to be matched to optimal treatment and to explore potential patient-centered barriers to uptake. Specifically, we assessed the effect of past pharmacotherapy use in prior quit attempts and beliefs regarding the relative importance of various factors (i.e., medication, the support of friends and family, having God's help and willpower) in determining one's ability to quit on smokers' stated willingness to undergo genetic assessment in order to be matched to the medication that will work best for them. We also assessed whether smokers' responses differed by race in an effort to understand whether we should anticipate racial differences in the uptake of PGx treatment for smoking.
We focused on potential differences in attitudes and beliefs among white and African Americans because African Americans currently experience the greatest burden of smoking-related illness and death in the USA.[33,34] Identifying and addressing potential barriers to successful uptake of more efficacious treatments among African Americans is thus an important public health concern. We hypothesized that willingness to undergo genetic testing would vary significantly depending on beliefs smokers held regarding which factors determine a smoker's ability to quit. Specifically, we hypothesized that smokers who believed medications or an individual's genetic profile to be very important in determining a person's ability to quit would be positively disposed towards PGx treatment, while those ranking other factors (e.g., having friends and family who support the quit attempt, willpower or having spiritual support) as very important would be less willing to undergo genetic testing in order to receive tailored treatment. Based on previous literature exploring racial differences in patients' willingness to undergo genetic testing in other contexts[35–39] and our previous qualitative study, we also further hypothesized that African American smokers would express less willingness than white smokers to undergo genetic testing.
Personalized Medicine. 2013;10(8):813-825. © 2013 Future Medicine Ltd.