Procedures
EMA
The sample included participants who met trial eligibility criteria and attended the first treatment visit where half of the sample was randomized to a standard course of varenicline treatment (12 weeks initiated 1 week prior to their target quit day) and half to an extended course (15 weeks initiated 4 weeks prior to their target quit day). Participants in the standard course received a placebo during the 3 weeks prior to varenicline initiation. Participants received up to 6 in-person smoking cessation counseling sessions during the 9-week EMA protocol (see [Daily data collection was completed using mobile EMA software (ilumivu), a smartphone-based EMA platform that operates on Android and Apple devices. Participants could use their personal smartphone or a loaned Samsung Galaxy “study phone” running on Android. Assessment schedules were based on the participant’s usual wake-up time. Participants completed a brief (~15 minutes) training including an overview of the application and a practice assessment. Participants were given a “frequently asked questions” handout and a “check-in” call was completed during the first week of the EMA period (the baseline week) for troubleshooting and compliance review. Technical problems and compliance were also reviewed at each in-person visit (up to 7 visits occurring every 1-2 weeks), and participants could call the study office if they had any technical problems.Two types of brief EMA were administered: morning assessments (1 per day) and random assessments (4 per day). Participants earned US $1 per assessment completed and were paid at each in-person visit. To be eligible for the study, participants were required to achieve 40% compliance for morning assessments and 50% for random assessments during the baseline week. Participants who did not meet the minimum compliance completed a second baseline week (n=17) and were excluded if they continued to fall below the requirement (n=8; only the second baseline week data were included in the present analyses for participants who were eligible after the second attempt). During the study, the eligibility criterion for the random assessments was dropped to reduce participant burden; 27% (n=70) of participants in this sample were recruited after this criterion was removed. A supplemental analysis suggested that removing this eligibility criterion did not contribute to significant differences in compliance rates (