All analyses were conducted using SPSS 15.0 software (SPSS, Inc.). After verifying that all treatment groups were similar across demographic and tobacco-related variables, we evaluated treatment effects on multiple outcome variables including: 1) CO-confirmed 7-day point-prevalence abstinence at 1 week post-quit, end of treatment (8 weeks post-quit) and 6 months post-quit; 2) number of days to lapse (latency to smoke a first cigarette after the TQD); 3) number of days to relapse (latency to smoke on 7 consecutive days after the TQD); 4) latency to relapse after the first lapse; and 5) initial cessation (whether the participant went at least 1 day without smoking in the first week post-quit; due to missing data n = 1424 for this outcome). Logistic regression was used for dichotomous outcomes (e.g., 7-day point-prevalence abstinence) while Cox regression was used for continuous outcomes (e.g., latency to lapse).
