Pilot Trial of a Game Embedded in a Smartphone App for Smoking Cessation

Number of times the app was opened; passively collected by the app and averaged in analysis to calculate mean number of app opens by study group over the study period. A new session is defined as use of the app after at least 30 minutes of inactivity.

Passively collected by the app and averaged in analysis among those with a session to calculate mean number of minutes of usage per session by study group.

Number of unique days with at least one app session, passively collected by the app and averaged by study group.

Proportion of participants who self-report having abstained for the prior 7 days during the 2-month follow-up assessment, assuming missing = smoking.

Proportion of participants who who self-report having abstained for the prior 30 days during the 2-month follow-up assessment, assuming missing = smoking.

Rating of satisfaction with assigned app on a 5-point Likert scale from "Not at all" (1) to "Extremely" (5), assessed in the 2-month follow-up questionnaire. The measure is averaged by study group.

Rating of satisfaction with the game on a 5-point Likert scale from "Not at all" (1) to "Extremely" (5), assessed in the 2-month follow-up questionnaire. The measure is averaged for the intervention group.

Proportion of participants who who self-report having abstained for the prior 7 days during the 2-month follow-up assessment, verified by saliva cotinine test, assuming missing = smoking. Averaged by study group. Recoded to 0 if the person reported having smoked during the same 7-day window during repeated measurement of daily smoking in the app.

Proportion of participants who who self-report having abstained for the prior 30 days during the 2-month follow-up assessment, verified by saliva cotinine test, assuming missing = smoking. Averaged by study group. Recoded to 0 if the person reported having smoked during the same 30-day window during repeated measurement of daily smoking in the app.

Proportion of days in which participants self-report having abstained in the last 24 hours, collected via a pop-up box that appears the first time each day a participant opens the app. Averaged by study group.

Number of non-game (core app) activities completed in the app by activity type: passively collected by the app to assess number of times the participant completed the following activity types: reported a craving, recorded a diary, completed a mission, read a tip, used the chatbot.

Number of in-game gifts unlocked during the study period (intervention group only); a summary measure of intensity of engagement (dose of treatment) of the app; passively collected by the app.

Number of game activities completed in the app by activity type; passively collected by the app to assess number of times the participant completed the following activity types: navigated to the game dashboard, completed each pet care activity (breathing exercise, feeding, washing, memory mini-game), visited the park, entered the dragon guide.

Rating of whether would recommend assigned app to a friend on a 5-point Likert scale from "Not at all" (1) to "Extremely" (5), assessed in the 2-month follow-up questionnaire. The measure is averaged by study group.

Motivation to quit, reported on a 10-point scale from not at all motivated (0) to very unmotivated (10) and assessed in the 2-month follow-up.

The measure includes items from the Bonding and Confidence subscales from the Mobile Agnew Relationship Measure, a scale of digital therapeutic alliance. Two items from each of the Bonding and Confidence subscales were included. Each item was asked on a 4-point Likert scale from strongly disagree (1) to strongly agree (4). The subscale items were combined to give a total possible score of 16 and a range of 4 (low alliance) to 16 (high alliance). The measure is averaged by study group. Assessed in the 2-month follow-up.