The primary endpoint of this study was the week 12, 7-day point-prevalence, biochemically confirmed, smoking abstinence rate. These cessation rates were tested using two-sided chi-squared tests. With about 172 minorities and over 1,500 whites, this study had 80% power to detect a clinically significant 10% point difference in smoking abstinence rates between the two groups (assuming a baseline success rate of 25% for each of the treatments).
