Design, baseline characteristics, and retention of African American light smokers into a randomized trial involving biological data.
BACKGROUND
African Americans experience significant tobacco-related health disparities despite the fact that over half of African American smokers are light smokers (use ≤ 10 cigarettes per day). African Americans have been under-represented in smoking cessation research, and few studies have evaluated treatment for light smokers. This paper describes the study design, measures, and baseline characteristics from Kick It at Swope III (KIS-III), the first treatment study of bupropion for African American light smokers.


METHODS
Five hundred forty African American light smokers were randomly assigned to receive bupropion (150 mg bid) (n = 270) or placebo (n = 270) for 7 weeks. All participants received written materials and health education counseling. Participants responded to survey items and provided blood samples for evaluation of phenotype and genotype of CYP2A6 and CYP2B6 enzymes involved in nicotine and bupropion metabolism. Primary outcome was cotinine-verified 7-day point prevalence smoking abstinence at Week 26 follow-up.


RESULTS
Of 2,628 individuals screened, 540 were eligible, consented, and randomized to treatment. Participants had a mean age of 46.5 years and 66.1% were women. Participants smoked an average of 8.0 cigarettes per day, had a mean exhaled carbon monoxide of 16.4 ppm (range 1-55) and a mean serum cotinine of 275.8 ng/ml. The mean Fagerström Test for Nicotine Dependence was 3.2, and 72.2% of participants smoked within 30 minutes of waking. The average number of quit attempts in the past year was 3.7 and 24.2% reported using pharmacotherapy in their most recent quit attempt. Motivation and confidence to quit were high.


CONCLUSIONS
KIS-III is the first study designed to examine both nicotine and bupropion metabolism, evaluating CYP2A6 and CYP2B6 phenotype and genotype in conjunction with psychosocial factors, in the context of treatment of African American light smokers. Of 1629 smokers screened for study participation, only 18 (1.1%) were ineligible to participate in the study because they refused blood draws, demonstrating the feasibility of recruiting and enrolling African American light smokers into a clinical treatment trial involving biological data collection and genetic analyses. Future evaluation of individual factors associated with treatment outcome will contribute to advancing tailored tobacco use treatment with the goal of enhancing treatment and reducing health disparities for African American light smokers.


BACKGROUND
ClinicalTrials.gov: NCT00666978.
Department of Preventive Medicine and Public Health, University of Kansas Medical Center, Kansas City, KS, USA. lcox@kumc.edu
Lisa Sanderson
LS
Cox
Babalola
B
Faseru
Matthew S
MS
Mayo
Ron
R
Krebill
Tricia S
TS
Snow
Carrie A
CA
Bronars
Nicole L
NL
Nollen
Won S
WS
Choi
Kolawole S
KS
Okuyemi
Gary A
GA
Salzman
Neal L
NL
Benowitz
Rachel F
RF
Tyndale
Jasjit S
JS
Ahluwalia
D000328:Adult; D001741:Black or African American / Q000235:genetics / Q000523:psychology / Q000706:statistics & numerical data*; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism; D016642:Bupropion / Q000097:blood / Q000627:therapeutic use*; D003367:Cotinine / Q000031:analogs & derivatives / Q000097:blood; D003376:Counseling; D065637:Cytochrome P-450 CYP2A6; D065702:Cytochrome P-450 CYP2B6; D005260:Female; D005838:Genotype; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007615:Kansas; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009538:Nicotine / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000235:genetics / Q000378:metabolism; D010353:Patient Education as Topic; D018579:Patient Selection; D010641:Phenotype; D012008:Recurrence; D012463:Saliva / Q000378:metabolism; D012907:Smoking / Q000208:ethnology / Q000378:metabolism / Q000523:psychology; D016540:Smoking Cessation / Q000208:ethnology / Q000379:methods* / Q000523:psychology; D000074606:Smoking Prevention; D013997:Time Factors; D014029:Tobacco Use Disorder / Q000208:ethnology / Q000378:metabolism / Q000523:psychology / Q000628:therapy*; D016896:Treatment Outcome
D016642:Bupropion; C001381:hydroxycotinine; D009538:Nicotine; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; C585599:CYP2B6 protein, human; D065637:Cytochrome P-450 CYP2A6; D065702:Cytochrome P-450 CYP2B6; D010089:Oxidoreductases, N-Demethylating; D003367:Cotinine
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