The primary endpoint was 4-week continuous abstinence for the last 4 weeks of treatment (weeks 9–12). Abstinence at each visit was defined as a self-report of no smoking since the previous visit, confirmed by an expired CO level of 10 ppm or less. In the case of missed visits, if at the next visit there was a self-report of no smoking and no use of other tobacco products, a status of not smoking was imputed. This sample was previously examined by King et al who reported association of multiple nicotinic receptor genes including CHRNA5 (reported variant rs518425 has low correlation with rs16969968) and abstinence in the varenicline arm (King et al., 2012). This paper presents new analyses targeting the comparison of cNRT vs. placebo arms focusing on the CHRNA5 rs16969968 genotype.
