Participants and procedures
verbal initiation of the voluntary, Cancer
RECRUITMENT, CANCER
Individual adults were recruited online through Craigslist advertisements, and participants completed all study protocols and interviews remotely from their preferred location using a secure online videoconferencing platform. This method extended our reach of recruitment and addressed the in-person limitations caused by the COVID-19 pandemic and associated state and local social isolation policies that restricted in-person interactions. Individuals who viewed the study advertisement followed a link to complete an online survey to demonstrate interest in the study, after which they made a voluntary request to be contacted by the study team. The study staff contacted those individuals with positive screens by phone to interview each person and confirm their eligibility for the study. A 15-minute phone screening was used to determine initial study eligibility and to schedule a baseline interview for those who passed the screening phase. During the screening call, the staff confirmed the participant’s current smoking status (eg, smoking 5 or more cigarettes per day for the past 2 years). Those who passed screening received electronic informed consent documents to e-sign and return after completing a phone-based verbal informed consent process, which was led by a trained member of the study staff.After providing consent, individuals were assessed for additional eligibility criteria during a baseline videoconferencing interview led by trained study staff. Those who met the criteria transitioned to participant status and received the baseline survey to complete before their remote interview with the study staff. The baseline interview lasted approximately 120 minutes, during which participants completed surveys, participated in a 20-minute motivational interview counseling session, and received instruction on study participation and when to start their quit attempt. This motivational interviewing session was conducted by trained staff members, who provided all participants with a 20-minute smoking cessation counseling session. The session was structured into 5 modules covering the following areas: 1) tobacco use and past quit attempts, 2) level of dependence and withdrawal symptoms, 3) smoking triggers and strengths and barriers regarding quitting, 4) quit strategies, and 5) anticipating and planning for lapses. Participants also received an electronic copy of the National Cancer Institute’s workbook, At the end of the baseline interview, participants were enrolled in the trial and randomly assigned to a study group. Participants were informed that they could use their assigned app at will throughout the follow-up period. Study staff helped participants install and register the assigned app on their personal smartphone. Staff members who were unblinded to a participant’s study group did not complete the outcome assessment for that participant.Participants voluntarily completed their daily app-based intervention for 14 days, and then attended a postintervention interview on their scheduled quit date. The immediate postintervention interview included verbal initiation of the voluntary quit attempt as well as completion of surveys and interviews. All app content remained available for use by participants during the postintervention follow-up period. Participant compensation reached a possible maximum of $300: completing the screening baseline intake survey ($30), baseline interview ($40), daily phone prompt reporting of the number of cigarettes smoked ($15 possible per week across 28 days, for a maximum of $60), daily audio app training ($2.50 for each of 28 possible app-based intervention sessions over 14 days, for a maximum of $70 paid as a lump sum at the postintervention videoconferencing interview), postintervention videoconferencing interview ($40), and 28-day follow-up surveys ($20), with a $40 bonus for completing more than 80% of surveys across 28 days of daily diary assessments.