activity>slow activity) and CYP2B6 (coded as normal activity>intermediate activity>slow activity) also did not alter the association between rs2036527 and rs588765 with smoking abstinence. A detailed description of the specific CYP2A6 and CYP2B6 alleles assessed was reported previously, and included CYP2A6*2, *4, *9, *17, *20, *23, *24, *25, *26, *27, *31, &*35 and CYP2B6*4, *6, *9, *18, &*22 (30, 31). The P-values were not adjusted for multiple comparisons. Because there were 4 independent SNPs, we considered P-values below 0.0125 (i.e. 0.05/4) to be statistically significant. The number needed to treat represents the average number of patients needed to treat with the active versus placebo pharmacotherapy to prevent one patient from smoking relapse. Statistical analyses were performed using Stata 12 (StataCorp, College Station, TX).
