Testing the Integrated mHealth App Intervention "SiS-H"

Time spent applying content will be measured with the self-report item: "During the past week, how much time did you spend applying or contemplating the content of the [Smiling Instead of Smoking app / QuitGuide app (logic-branched by treatment group)]? ______________ (in minutes, total for the week)").

A percentage based on the categorical re-coding of the actual app usage, measured in days, where YES indicates that participants used the app at least once during 6 out of the 8 weeks of the prescribed treatment weeks, and NO indicates that participants used the app less often.

Assessed using an 8-item measure in which participants rate the extent to which they agree or disagree with statements about the smoking cessation support they received and the things they did while quitting (5-point Likert scale, 1=strongly disagree, 5=strongly agree, e.g., "I used techniques to help me relax"). Higher scores indicate greater use of smoking cessation strategies.

As measured using the Client Satisfaction Scale (CSQ-8), an 8-item multiple choice measure that will be used to assess participants' satisfaction with the smoking cessation support they receive (e.g., "How satisfied are you with the amount of help you received?"). Scores are summed across items and range from 8 to 32, with higher scores indicating greater satisfaction.

As assessed via the System Usability Scale (SUS), a ten-item attitude scale giving a global view of subjective assessments of usability, adapted to include language specific to the smoking app (e.g., "I found the smoking app unnecessarily complex" 5-point Likert: 1 = strongly disagree, 5 = strongly agree). Scale scores range from 0 to 100 with greater scores indicating a more favorable perception of usability of the app.

User app ratings will be assessed using the Mobile Application Rating Scale user version (uMARS). The uMARS is a self-report form with 26 items that assess participants' evaluations of various app features. Dimensions of this measure include engagement (5 items), functionality (4 items), aesthetics (3 items), information quality (4 items), app subjectivity quality (4 items), and perceived impact (6 items). Items are rated on differently worded 5-point Likert scales ranging from 1 (Inadequate) to 5 (Excellent). An overall app rating score can be calculated as the mean score of the first 16 questions (range of 1-5), with higher scores meaning higher overall perceived app quality.

The Smoking Self-Efficacy Questionnaire (SEQ-12) is a two-dimensional 12-item self-report scale measuring a person's confidence in his or her ability to abstain from smoking when facing internal stimuli (e.g. feeling depressed) and external stimuli (e.g. being with smokers) on a 0-100 slider scale (i.e., 0=not at all confident that I can refrain; 100=extremely confident that I can refrain). Scale scores are created by mean scoring across items and range from 0 to 100. Higher scores indicate greater self-efficacy to abstain from smoking.

Positive affect will be measured using the Positive and Negative Affect Schedule (PANAS). This 20-item scale asks participants to indicate how they felt in the past week, using a 5-point Likert scale ranging from 1="very slightly or not at all" to 5="extremely." Scores for 10 positive words and 10 negative words will be summed separately and will be reported as mean scores (not scale totals) ranging from 1-5, with lower scores indicating low (positive or negative) affect and higher scores indicating high (positive or negative) affect. The 10 items for POSITIVE (PA) affect are attentive, interested, alert, excited, enthusiastic, inspired, proud, determined, strong, and active.

Negative affect will be measured using the Positive and Negative Affect Schedule (PANAS). This 20-item scale asks participants to indicate how they felt in the past week, using a 5-point Likert scale ranging from 1="very slightly or not at all" to 5="extremely." Scores for 10 positive words and 10 negative words will be summed separately and will be reported as mean scores (not scale totals) ranging from 1-5, with lower scores indicating low (positive or negative) affect and higher scores indicating high (positive or negative) affect. The 10 items for NEGATIVE (NA) affect are distressed, upset, hostile, irritable, scared, afraid, ashamed, guilty, nervous, and jittery.

Smoking urges will be assessed using the Questionnaire of Smoking Urges. This 10-item scale assesses overall nicotine dependence, craving, and smoking withdrawal symptoms. Items will be rated on a 7-point Likert-scale ranging from 1=Strongly disagree to 7=Strongly agree. We will present the mean instead of total scores for ease in interpretation, so that scale scores can range from 1.0 to 7.0, with higher scores indicating greater smoking urges.

Smoking attitudes will be assessed using the Attitudes Towards Smoking Scale (ATS-18). The 18-item self-report ATS-18 measures attitudes towards smoking in current and former cigarette smokers. It is rated on a 5-point Likert scale, from 1="strongly disagree" to 5="strongly agree.". The ATS-18 has 3 sub-scales: Adverse effects of smoking (items 1-10), psychoactive benefits of smoking (items 11-14), and pleasure of smoking (items 15-18). To score, all items per sub-scale will be averaged to obtain a mean score within each sub-scale. For each sub-scale, higher scores indicate greater agreement with the specific attitude towards smoking.

Smoking attitudes will be assessed using the Attitudes Towards Smoking Scale (ATS-18). The 18-item self-report ATS-18 measures attitudes towards smoking in current and former cigarette smokers. It is rated on a 5-point Likert scale, from 1="strongly disagree" to 5="strongly agree.". The ATS-18 has 3 sub-scales: Adverse effects of smoking (items 1-10), psychoactive benefits of smoking (items 11-14), and pleasure of smoking (items 15-18). To score, all items per sub-scale will be averaged to obtain a mean score within each sub-scale. For each sub-scale, higher scores indicate greater agreement with the specific attitude towards smoking.

Smoking attitudes will be assessed using the Attitudes Towards Smoking Scale (ATS-18). The 18-item self-report ATS-18 measures attitudes towards smoking in current and former cigarette smokers. It is rated on a 5-point Likert scale, from 1="strongly disagree" to 5="strongly agree.". The ATS-18 has 3 sub-scales: Adverse effects of smoking (items 1-10), psychoactive benefits of smoking (items 11-14), and pleasure of smoking (items 15-18). To score, all items per sub-scale will be averaged to obtain a mean score within each sub-scale. For each sub-scale, higher scores indicate greater agreement with the specific attitude towards smoking.

Negative smoking expectancies will be assessed using the Decisional Balance Inventory (DBI) for Smoking Short Form. This 6-item form assesses the personal importance people place on positive and negative smoking expectancies. Items are rated on slider scales ranging from 0="not at all important" to 100="extremely important." Two sub-scale mean scores will be calculated: positive expectancies (3 items), and negative smoking expectancies (3 items). On both scales, higher scores indicate a greater importance of the smoking expectancies (positive or negative).

Positive smoking expectancies will be assessed using the Decisional Balance Inventory (DBI) for Smoking Short Form. This 6-item form assesses the personal importance people place on positive and negative smoking expectancies. Items are rated on slider scales ranging from 0="not at all important" to 100="extremely important." Two sub-scale mean scores will be calculated: positive expectancies (3 items), and negative smoking expectancies (3 items). On both scales, higher scores indicate a greater importance of the smoking expectancies (positive or negative).

The depth of the thought-action repertoire will be assessed using a modified version of the Open-Ended Twenty Statements Test (MOETST). The original MOETST usually starts by evoking an emotion, asks participants to name the emotion they experienced and keep it in mind, and then list all the things they would like to do 'right now'. Instead of using emotion inductions, we will ask participants to think of their upcoming quit date (at baseline) or when last using their assigned app treatment, and then fill out as many action statements as they can think of (limited to a maximum of 20) with the prompt "Instead of smoking at that moment, I could have ....". The number of actions will be summed to produce a thought-action repertoire score with a range of 0-20, with higher scores indicating a richer thought-action repertoire.