Predictors of cessation in African American light smokers enrolled in a bupropion clinical trial

Background: This is the first study to examine predictors of successful cessation in African American (AA) light smokers treated within a placebo-controlled trial of bupropion. Methods: We analyzed data from a randomized, double-blind, placebo-controlled trial of bupropion and health education for 540 African American light smokers. African American light smokers (≤ 10 cigarettes per day, cpd) were randomly assigned to receive 150. mg bid bupropion SR (n = 270) or placebo (n = 270) for 7. weeks. All participants received health education counseling at weeks 0, 1, 3, 5 and 7. Using chi-square tests, two sample t-tests, and multiple logistic regression analyses, we examined baseline psychosocial and smoking characteristics as predictors of cotinine-verified 7-day point prevalence smoking abstinence among study participants at the end treatment (Week 7) and at the end of follow-up (Week 26). Results: Participants who received bupropion were significantly more likely to quit smoking compared to those who received placebo (OR = 2.72, 95% CI = 1.60-4.62, P = 0.0002). Greater study session attendance (OR = 2.47, 95% CI = 1.76-3.46, P = 0.0001), and smoking non-menthol cigarettes increased the likelihood of quitting (OR = 1.84, 95% CI = 1.01-3.36, P = 0.05); while longer years of smoking (OR = 0.98, 95% CI = 0.96-1.00, P = 0.05) and higher baseline cotinine (OR = 0.97, 95% CI = 0.95-0.99, P = 0.002) significantly reduced the odds of quitting at Week 7. Conversely, at the end of follow-up (Week 26), treatment with bupropion vs. placebo (OR = 1.14, 95% CI = 0.65-2.02, P = 0.64) was not significantly associated with quitting and type of cigarette smoked (menthol vs. non-menthol) did not appear in the final logistic regression model. Greater study session attendance (OR = 1.96, 95% CI = 1.44-2.66, P = 0.0001); BMI (OR = 1.03, 95% CI = 1.00-1.07, P=0.04); and weight efficacy (OR = 1.03, 95% CI = 1.01-1.05, P = 0.01) increased the likelihood of quitting at Week 26. Similar to our findings at Week 7, longer years of smoking (OR = 0.96, 95% CI = 0.94-0.99, P = 0.01) and higher baseline cotinine (OR = 0.97, 95% CI = 0.95-0.99, P = 0.02) significantly reduced the odds of quitting at Week 26. Conclusions: Baseline cotinine levels, number of years smoked and study session attendance are associated with both short- and long-term smoking cessation, while bupropion and the type of cigarette smoked were associated with quitting on short term only.