Association tests focusing on overall nicotine dependence and number of quit attempts were done using PBAT on the group of “current frequent smokers”. Significant associations in the NYS-FS are shown in Table 6. In cases where the p-value within Caucasians is different than across ethnic groups it is given. In examining overall nicotine dependence, rs2304297 showed association in Caucasians (p=0.0066). In the case of number of quit attempts, three SNPs at the upstream end of CHRNB3 showed significant association under a recessive model (rs7004381, p=0.0024; rs4950, p=0.021; rs13280604, p=0.024). Marker rs2304297 in the 3’ region of CHRNA6 was associated also with number of quit attempts in Caucasians (p=0.0044). Using a Bonferroni correction for multiple testing (8 SNPs and 2 phenotypes = 16 tests) the cutoff for a 5% significance level would be a p-value < 0.003. Only the association of rs7004381 with quit attempts is significant at this level. However, it is worth noting that this cutoff is overly conservative due to both correlations between the SNPs (LD) and between the two phenotypes.
