The primary outcome was the biochemically confirmed 7-day abstinence at end of treatment (EOT, 8 weeks post-quit). All self-reports of abstinence were confirmed by an expired carbon monoxide (CO) level of less than 10 parts per million (ppm). Individuals with missing data were considered to be smoking. This sample was previously examined by Chen et al. (2012) who reported the interaction of CHRNA5 and medication on smoking abstinence (Chen et al., 2012). This paper presents new analyses targeting the effect of CHRNA5 rs16969968 in the cNRT and placebo arms.
