Alcohol Use Disorder (AUD)
Conditions
Keywords
Approach Bias Modification, Alcohol, Alcohol Use Disorder, Addiction, Cognitive Bias Modification, mHealth, Smartphone App
Brief summary
Cognitive biases contribute to the difficulty experienced by heavy drinkers wishing to reduce their alcohol use. Recent interventions designed to reduce cognitive biases demonstrate efficacy for Approach Bias Modification (ApBM). Reductions in the likelihood of relapse have been found after ApBM in Alcohol Use Disorder (AUD) patients during residential treatment. Current methods of ApBM are usually delivered by computer and joystick and come with several limitations, including accessibility. If ApBM could be shown to be feasible in other settings, such as outpatient treatment, it could benefit a much larger population with AUD. This randomised controlled trial will test the efficacy of a recently-developed ApBM smartphone app called AAT-App (Alcohol Avoidance Training App). We aim to test whether AAT-App, relative to a minimal version of the app which excludes ApBM training, is effective at reducing alcohol use, cravings, severity of dependence, and approach bias (a measure of a person's automatic tendency to automatically approach alcohol-related stimuli), and to explore user experiences of AAT-App to guide future improvements to the app and its implementation.
Detailed description
Aims: We aim to determine whether providing the active version of AAT-App (including ApBM) to people accessing outpatient alcohol treatment from AOD services, is effective, relative to a minimal version of the app which does not include ApBM training, at reducing alcohol use, cravings, and severity of dependence. We also aim to test the psychometric properties of the mobile phone approach bias measure we developed, and whether engaging in AAT-App significantly reduces approach bias, relative to the minimal control condition. We also aim to explore user experiences of AAT-App's, perceived alignment with treatment, and suggested improvements, using qualitative interviews in a subset of participants, to guide further future improvements to the app and its implementation. Design & Setting: We will conduct a double-blind, randomised, parallel-group controlled superiority trial with alcohol treatment outpatients in Melbourne, Victoria. Participants will be randomised to one of 2 groups with a 1:1 allocation ratio. Both participants and researchers completing the follow-up interviews will be unaware (blinded) of the condition to which they have been randomly allocated. Recruitment: Staff at participating services will briefly explain the opportunity to participate in a study testing a brain-training app to clients who they believe may meet eligibility criteria. To preserve blinding, no specific details will be provided regarding approach bias modification, and participants will merely be informed that the study tests a new smartphone 'brain-training app' that involves doing brief game-like tasks on your phone each week for 4 weeks. Clients who are interested will need to provide consent to be contacted by the research team, who will conduct screening for eligibility, provide more complete participant information, and conduct recruitment. Screening: Research staff will phone clients who have provided consent to be contacted to confirm eligibility (administering the Alcohol Use Disorders Identification Test (AUDIT), checking age and phone operating system, confirming that they have no plans to enter residential/inpatient treatment in the next month, confirming absence of past-month residential rehabilitation and any past-week inpatient treatment (e.g., hospitalisation or residential withdrawal), as well as asking about number of days spent in inpatient treatment in the past month if the person underwent any inpatient treatment prior to the previous week). Randomisation and blinding of allocation: Six computer-generated randomisation sequences (one for each recruitment site) will be produced by a data scientist who is not otherwise involved in recruitment or data collection, processing, or analysis, using a 1:1 allocation ratio, based on blocks of variable size (ranging from 2-6). As such, randomisation will be stratified by site. The app developers (ANT Development Studios Ltd.) will provide the data scientist with two lists of app access codes which will direct participants to either the intervention or minimal version of AAT-App when they first download and open the app. Using these lists and the randomisation sequence, the data scientist will generate a separate spreadsheet of access codes for each site (based on the site-stratified randomisation sequence). Researchers will send these codes to participants as they are recruited from each respective site. Researchers involved in recruitment will only have access to a spreadsheet displaying a single list of codes to be sent to participants at each respective site, while the randomisation sequence will be stored in a password-protected file provided to the trial statistician and to one research officer who will remain unblinded to assist with coordinating qualitative interviews. Neither the randomisation file, nor its password will be provided to any other staff involved in recruitment or in pursuing follow-ups or quantitative data management until all data analysis is complete. Data collection windows for post-intervention and follow up assessments: 1. Post-intervention (28 days post-baseline): Participants will be provided with an in-app link to a Qualtrics survey, in which the link will expire if the survey is not completed within 7 days (i.e., 28-35 days post-baseline). 2. 1-month follow up (56 days post-baseline): Participants will be prompted with an app notification reminder to report their past-month alcohol consumption via the in-app calendar and complete a Qualtrics survey, in which the link will expire after 2 weeks (i.e., 56-70 days post-baseline). 3. 3-month follow up (112 days post-baseline): Participants will be prompted with an app notification reminder to report their past-month alcohol consumption and complete a Qualtrics survey, in which the link will expire after 28 days (i.e.,112-140 days post-baseline). Statistical analyses: Primary outcome: A linear mixed-effects model (LMM) will be used to compare change in mean standard drinks consumed per week between groups across 4 time points (baseline, post-intervention, 1-month follow-up, and 3-month follow-up). This model will test the main effects of time and group and (most crucially for determining efficacy) the group x time interaction. Planned follow-up comparisons between groups at post-intervention, 1-month follow-up, and 3-month follow-up time-points will be conducted using t-tests, with post-intervention being the primary endpoint. A secondary sensitivity analysis will be conducted excluding a participant's data from any time-point where they had been in residential/inpatient treatment in the past week (i.e., restricting analyses to time-points where a participant's opportunity to drink had not been limited by hospitalisation, rehabilitation, etc.). If a difference between groups is found post-intervention, a secondary LMM analysis of difference between groups in change in weekly standard drinks during the intervention period (i.e., 5 levels of time: Baseline, week 1, week 2, week 3, post-intervention) will be conducted to examine how quickly differences between groups emerge, with t-tests used to compare groups at week 1, 2, 3, and post-intervention time-points. This secondary analysis will be conducted excluding participants who had engaged in any residential/inpatient treatment within the intervention period. Secondary outcomes: Continuous outcome variables (Craving Experience Questionnaire frequency scale (CEQ-F) scores, Severity of Dependence Scale scores, AUDIT scores, past-week heavy drinking days (HDDs), past-month drinking days, Australian Treatment Outcome Profile quality of life items, and approach bias) will be analysed in a similar manner to the primary analysis described above. Sensitivity analysis of past-week drinking days to control for the possible effect of past-week residential/inpatient treatment will be conducted as described for the primary outcome. Past-month drinking days will be expressed as a percentage of the total number of days on which a participant had the opportunity to drink (i.e., if a participant was in residential/inpatient treatment for 10 days at a certain time point, then for that time point, their past-month drinking days will be expressed as a proportion of the remaining 18 days on which they had the opportunity to drink), although data will be excluded at any time point where the participant did not have at least 14 days on which they had the opportunity to drink alcohol (i.e., if they were within residential/inpatient treatment on 15 or more days). For CEQ-F, secondary analyses will be conducted for each of its 3 subscales. Analyses of AUDIT scores will use 2 levels of time (baseline, 3-month follow-up). Approach bias analyses will also use 2 levels of time (baseline, post-intervention) and approach bias scores will be analysed separately for alcohol and positive images. As past-month HDDs can only be calculated at 1 time point (post-intervention), they will simply be compared between groups using a t-test post-intervention after converting scores to a proportion of days on which the participant had an opportunity to drink (as described for past-month drinking days). Proportions of groups reporting complete past-week and past-month abstinence will be compared between groups at post-intervention, 1-month follow-up, and 3-month follow-up using Pearson's chi-squared. Mobile Application Rating Scale 'functionality', 'aesthetics', and 'subjective quality' scores, and participants' subjective ratings regarding AAT-App's effect on drinking and cravings will be explored within each group separately using descriptive data (e.g., mean, median, quartile cut-offs, percentages scoring above 3) to quantify typical ratings and proportions of participants providing favourable ratings. Where relevant, exploratory analyses will also compare mean scores of uMARS scales between groups using t-tests. Qualitative study: Interview transcripts will be subjected to a thematic qualitative analysis in order to identify underlying themes and patterns within each respondent's discourse. Thematic analysis will proceed according to the six stage process described by Braun and Clark. The coding process will be primarily conducted by two researchers, and a third researcher will oversee and verify coding decisions to ensure agreement and consistency throughout the process. The digital qualitative data analysis software NVivo 11.4.0 will be used to facilitate qualitative data analysis. Free-text responses to app acceptability questions in the post-intervention survey will be reviewed primarily to identify reports of functionality issues (e.g., bugs in the app) and safety issues (e.g., reports of triggering). Any such issues will be catalogued to inform further improvements to the app (if necessary) and its delivery/implementation in future research and/or treatment contexts.
Interventions
Participants will receive the active AAT-App on their smartphone, which includes ApBM training, and prompted to engage with the app during the 28-day intervention period.
Participants will receive the minimal version of AAT-App, which does not include ApBM training, on their smartphone and prompted to engage with the app during the 28-day intervention period.
Sponsors
Study design
Masking description
Participants, investigators, and outcomes assessors will be unaware (blinded) of the condition to which participants have been randomly allocated.
Intervention model description
A double-blind, randomised, parallel-group controlled superiority trial with alcohol treatment outpatients will be conducted. Participants will be randomised to one of 2 groups with a 1:1 allocation ratio.
Eligibility
Inclusion criteria
* Own an Android or iOS smartphone with an Australian mobile number. * Be currently accessing outpatient treatment for alcohol problems. Participants with multiple drugs of concern are eligible as long as alcohol is one of the drugs of concern for the current episode of treatment. * Have an Alcohol Use Disorders Identification Test (AUDIT) score of at least 8.
Exclusion criteria
* Any residential rehabilitation within the past 4 weeks. * Any form of inpatient treatment (e.g. hospital or residential withdrawal treatment) within the past week. * Scheduled to enter inpatient/residential treatment within the next month.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Standard Drinks Consumed Per Week | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use | Participants will estimate the number of standard drinks of alcohol consumed on each day within the past week, using a timeline follow-back assessment. Participants will select a number, ranging from 0-80, to estimate how many standard drinks they consumed on each day in that week. Past-week standard drinks will be calculated using the sum of values for each of the past 7 days. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Severity of Dependence Scale (SDS) Scores | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use | The Severity of Dependence Scale (SDS) is a validated, 5-item scale, with each item scored 0-3. Total scores are calculated by summing individual item scores. Higher scores indicate more severe psychological dependence on the drug being enquired about (i.e., alcohol in this study) |
| Total Scores on the Alcohol Use Disorders Identification Test (AUDIT) | Baseline and 16 weeks after commencing app use | The Alcohol Use Disorders Identification Test (AUDIT) is a validated, 10-item scale, with each item scored 0-4. Total scores are calculated based on the sum of individual item scores. Given the AUDIT usually enquires about drinking and related problems in the past year, wording of instructions and questions was modified to ask participants to base answers on the past 3 months so that equivalent, non-overlapping periods were assessed at both baseline and the final follow-up. |
| Past-week Heavy Drinking Days (HDDs) | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use | Participants estimated the number of standard drinks of alcohol consumed on each day within the past week. Any day when they estimate they consumed at least 5 standard drinks in a day was considered an HDD. |
| Past-Month Drinking Days | Baseline, 8 weeks after commencing app use, and 16 weeks after commencing app use | At baseline, participants will complete the past-week drinking assessment described above and also report number of drinking days in each of the 3 weeks preceding the past week. 1-month and 3-month follow-up assessments will be identical to the baseline assessment. |
| Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use | The Craving Experience Questionnaire frequency scale (CEQ-F) is a validated, 10-item scale, with each item rated on a scale of 0-10. Total scores are calculated based on the mean of individual items. Higher scores indicate more frequent craving experiences. Three subscale scored can also be calculated: intensity (3 items), imagery (4 items), and intrusiveness (3 items). Secondary analyses will be conducted for each of its 3 subscales. |
| Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline, 8 weeks after commencing app use, and 16 weeks after commencing app use | Participants reporting zero drinking days in the past month will be classified as past-month abstinent. Predicted proportions from the linear mixed-effects model are entered using a measure type of mean, as advised by the trial statistician, because the model produces predicted means from the data (after coding abstinence as 1 and non-abstinence as 0) after the model accounts for complexities in the data, such as the repeated measures of the data, imbalances in group sizes, and assumptions regarding error correlation, random effects, fixed effects. |
| Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, 16 weeks after commencing app use. | 3 items will be adapted from the Australian Treatment Outcomes Profile (ATOP) assessing psychological health, physical health, and overall quality of life over the past 28 days. Each item will be rated on a scale from zero to ten, where zero is poor and ten is good. Each rating will be treated as a separate variable in analyses (i.e., no composite score will be derived from the 3 separate items). |
| Approach Bias | Baseline and Post-Intervention (28 days after commencing app use) | Approach bias will be assessed within the app using an alcohol approach avoidance task. The approach avoidance task is a behavioural task designed to measure alcohol approach bias, which is the tendency to approach alcohol-related stimuli more quickly than avoiding them (relative to the same tendency for neutral stimuli). This is calculated from reaction time differences according to the formula: (RTalc-avoid - RTalc-approach) - (RTneu-avoid - RTneu-approach), where RTs are the mean reaction times for alcohol avoidance, alcohol approach, neutral stimulus avoidance, and neutral stimulus approach reactions, respectively. Thus, a positive approach bias score reflects a tendency to make an approach movement towards alcohol images more quickly than to make an avoidance, and for that tendency to be larger than the equivalent tendency for neutral images. Scores do not have specific minimum or maximum values. |
| Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use | Past-week complete abstinence will be defined as zero days in the past week on which any alcohol was consumed. Predicted proportions from the linear mixed-effects model are entered using a measure type of mean, as advised by the trial statistician, because the model produces predicted means from the data (after coding abstinence as 1 and non-abstinence as 0) after the model accounts for complexities in the data, such as the repeated measures of the data, imbalances in group sizes, and assumptions regarding error correlation, random effects, fixed effects. |
Countries
Australia
Participant flow
Recruitment details
Recruitment commenced on May 25, 2022 and ended on January 22, 2024. Recruitment was open to people receiving outpatient treatment for alcohol problems in the state of Victoria, Australia.
Pre-assignment details
After providing informed consent to participate, participants (N=82) were sent a link to download the app. 3 participants who were enrolled did not download and install the app, hence the final sample assigned to groups comprised 79 participants.
Participants by arm
| Arm | Count |
|---|---|
| Active AAT-App Participants will receive the active AAT-App.
AAT-App: Participants will receive the active AAT-App on their smartphone, which includes ApBM training, and prompted to engage with the app during the 28-day intervention period. | 39 |
| Minimal AAT-App Participants will receive the minimal version of AAT-App.
Minimal AAT-App: Participants will receive the minimal version of AAT-App, which does not include ApBM training, on their smartphone and prompted to engage with the app during the 28-day intervention period. | 40 |
| Total | 79 |
Baseline characteristics
| Characteristic | Active AAT-App | Minimal AAT-App | Total |
|---|---|---|---|
| Age, Continuous | 48.8 years STANDARD_DEVIATION 9.5 | 44.5 years STANDARD_DEVIATION 10.8 | 46.6 years STANDARD_DEVIATION 10.3 |
| Race/Ethnicity, Customized Race African | 0 Participants | 1 Participants | 1 Participants |
| Race/Ethnicity, Customized Race East Asian or Southeast Asian | 0 Participants | 2 Participants | 2 Participants |
| Race/Ethnicity, Customized Race Latino / Latina | 0 Participants | 2 Participants | 2 Participants |
| Race/Ethnicity, Customized Race Prefer not to say | 1 Participants | 2 Participants | 3 Participants |
| Race/Ethnicity, Customized Race South Asian | 0 Participants | 1 Participants | 1 Participants |
| Race/Ethnicity, Customized Race White / European | 38 Participants | 32 Participants | 70 Participants |
| Region of Enrollment Australia | 39 participants | 40 participants | 79 participants |
| Sex: Female, Male Female | 18 Participants | 16 Participants | 34 Participants |
| Sex: Female, Male Male | 21 Participants | 24 Participants | 45 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 39 | 0 / 40 |
| other Total, other adverse events | 0 / 39 | 0 / 40 |
| serious Total, serious adverse events | 0 / 39 | 0 / 40 |
Outcome results
Number of Standard Drinks Consumed Per Week
Participants will estimate the number of standard drinks of alcohol consumed on each day within the past week, using a timeline follow-back assessment. Participants will select a number, ranging from 0-80, to estimate how many standard drinks they consumed on each day in that week. Past-week standard drinks will be calculated using the sum of values for each of the past 7 days.
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: The numbers describe how many participants were included in the linear mixed model (i.e., providing valid alcohol use data fro at least one time point). Numbers varied across time points (Baseline: 37 Active, 40 Minimal; Week 4: 29 Active, 32 Minimal; Week 8: 27 Active, 30 Minimal; Week 16: 20 Active, 27 Minimal), however, these were analysed using a single linear mixed-effects model which calculated estimated marginal means.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Number of Standard Drinks Consumed Per Week | Baseline | 38.469 standard drinks (10 grams alcohol) | Standard Error 5.612 |
| Active AAT-App | Number of Standard Drinks Consumed Per Week | Week 4 | 33.199 standard drinks (10 grams alcohol) | Standard Error 5.297 |
| Active AAT-App | Number of Standard Drinks Consumed Per Week | Week 8 | 27.929 standard drinks (10 grams alcohol) | Standard Error 5.397 |
| Active AAT-App | Number of Standard Drinks Consumed Per Week | Week 16 | 17.390 standard drinks (10 grams alcohol) | Standard Error 6.695 |
| Minimal AAT-App | Number of Standard Drinks Consumed Per Week | Week 16 | 26.268 standard drinks (10 grams alcohol) | Standard Error 6.108 |
| Minimal AAT-App | Number of Standard Drinks Consumed Per Week | Baseline | 29.645 standard drinks (10 grams alcohol) | Standard Error 5.427 |
| Minimal AAT-App | Number of Standard Drinks Consumed Per Week | Week 8 | 27.957 standard drinks (10 grams alcohol) | Standard Error 5.148 |
| Minimal AAT-App | Number of Standard Drinks Consumed Per Week | Week 4 | 28.801 standard drinks (10 grams alcohol) | Standard Error 5.124 |
Approach Bias
Approach bias will be assessed within the app using an alcohol approach avoidance task. The approach avoidance task is a behavioural task designed to measure alcohol approach bias, which is the tendency to approach alcohol-related stimuli more quickly than avoiding them (relative to the same tendency for neutral stimuli). This is calculated from reaction time differences according to the formula: (RTalc-avoid - RTalc-approach) - (RTneu-avoid - RTneu-approach), where RTs are the mean reaction times for alcohol avoidance, alcohol approach, neutral stimulus avoidance, and neutral stimulus approach reactions, respectively. Thus, a positive approach bias score reflects a tendency to make an approach movement towards alcohol images more quickly than to make an avoidance, and for that tendency to be larger than the equivalent tendency for neutral images. Scores do not have specific minimum or maximum values.
Time frame: Baseline and Post-Intervention (28 days after commencing app use)
Population: A linear mixed-effects model was used to analyse this outcome and included all participants who provided valid data for at least one time point. Numbers providing data at each individual time point, and predicted marginal means are provided below
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Approach Bias | Baseline | -69.67 units on a scale | Standard Error 21.17 |
| Active AAT-App | Approach Bias | Week 4 | -47.01 units on a scale | Standard Error 22.45 |
| Minimal AAT-App | Approach Bias | Baseline | -52.16 units on a scale | Standard Error 19.75 |
| Minimal AAT-App | Approach Bias | Week 4 | -44.08 units on a scale | Standard Error 19.44 |
Past-Month Drinking Days
At baseline, participants will complete the past-week drinking assessment described above and also report number of drinking days in each of the 3 weeks preceding the past week. 1-month and 3-month follow-up assessments will be identical to the baseline assessment.
Time frame: Baseline, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: A linear mixed-effects model analysing this outcome included all participants who provided data for at least one of the 3 time points at which it was measured. Numbers providing data at each time point, and predicted marginal means from the analysis, are reported below.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Past-Month Drinking Days | Baseline | 14.209 number of days any alcohol was consumed | Standard Error 1.601 |
| Active AAT-App | Past-Month Drinking Days | Week 8 | 13.087 number of days any alcohol was consumed | Standard Error 1.518 |
| Active AAT-App | Past-Month Drinking Days | Week 16 | 11.966 number of days any alcohol was consumed | Standard Error 1.878 |
| Minimal AAT-App | Past-Month Drinking Days | Baseline | 11.895 number of days any alcohol was consumed | Standard Error 1.569 |
| Minimal AAT-App | Past-Month Drinking Days | Week 8 | 11.245 number of days any alcohol was consumed | Standard Error 1.455 |
| Minimal AAT-App | Past-Month Drinking Days | Week 16 | 10.595 number of days any alcohol was consumed | Standard Error 1.701 |
Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F)
The Craving Experience Questionnaire frequency scale (CEQ-F) is a validated, 10-item scale, with each item rated on a scale of 0-10. Total scores are calculated based on the mean of individual items. Higher scores indicate more frequent craving experiences. Three subscale scored can also be calculated: intensity (3 items), imagery (4 items), and intrusiveness (3 items). Secondary analyses will be conducted for each of its 3 subscales.
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: All time points were analysed in a single linear mixed-effects model that included anyone who provided valid data for at least one time point. Estimated marginal means are shown below, along with numbers of participants providing data at each time point.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 4 | 3.773293 score on a scale | Standard Error 0.3136546 |
| Active AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 8 | 3.442836 score on a scale | Standard Error 0.318828 |
| Active AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Baseline | 4.103751 score on a scale | Standard Error 0.3370139 |
| Active AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 16 | 2.781920 score on a scale | Standard Error 0.4044861 |
| Minimal AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 16 | 2.886112 score on a scale | Standard Error 0.3737217 |
| Minimal AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 4 | 3.689666 score on a scale | Standard Error 0.3038462 |
| Minimal AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Baseline | 3.957517 score on a scale | Standard Error 0.3289793 |
| Minimal AAT-App | Past-Week Frequency of Alcohol Cravings (as Measured by the Craving Experience Questionnaire Frequency Scale - CEQ-F) | Week 8 | 3.421814 score on a scale | Standard Error 0.303745 |
Past-week Heavy Drinking Days (HDDs)
Participants estimated the number of standard drinks of alcohol consumed on each day within the past week. Any day when they estimate they consumed at least 5 standard drinks in a day was considered an HDD.
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: All time points were analysed in a single linear mixed-effects model including all participants who provided valid data for at least one time point. Estimated marginal means and numbers of participants contributing data at each time point are reported below.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 16 | 1.626 Heavy drinking days in a week | Standard Error 0.471 |
| Active AAT-App | Past-week Heavy Drinking Days (HDDs) | Baseline | 2.928 Heavy drinking days in a week | Standard Error 0.386 |
| Active AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 4 | 2.602 Heavy drinking days in a week | Standard Error 0.36 |
| Active AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 8 | 2.277 Heavy drinking days in a week | Standard Error 0.367 |
| Minimal AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 8 | 2.095 Heavy drinking days in a week | Standard Error 0.349 |
| Minimal AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 16 | 1.994 Heavy drinking days in a week | Standard Error 0.426 |
| Minimal AAT-App | Past-week Heavy Drinking Days (HDDs) | Week 4 | 2.145 Heavy drinking days in a week | Standard Error 0.348 |
| Minimal AAT-App | Past-week Heavy Drinking Days (HDDs) | Baseline | 2.195 Heavy drinking days in a week | Standard Error 0.372 |
Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments
Participants reporting zero drinking days in the past month will be classified as past-month abstinent. Predicted proportions from the linear mixed-effects model are entered using a measure type of mean, as advised by the trial statistician, because the model produces predicted means from the data (after coding abstinence as 1 and non-abstinence as 0) after the model accounts for complexities in the data, such as the repeated measures of the data, imbalances in group sizes, and assumptions regarding error correlation, random effects, fixed effects.
Time frame: Baseline, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: The mixed effects logistic regression model included all participants who provided data for this outcome for at least one time point. Numbers providing data for each specific time point and predicted proportions who were past-month abstinent from the model are provided below.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Active AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline | .160 proportion of participants abstinent |
| Active AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 8 | .232 proportion of participants abstinent |
| Active AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 16 | .303 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline | .224 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 8 | .256 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Month Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 16 | .288 proportion of participants abstinent |
Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments
Past-week complete abstinence will be defined as zero days in the past week on which any alcohol was consumed. Predicted proportions from the linear mixed-effects model are entered using a measure type of mean, as advised by the trial statistician, because the model produces predicted means from the data (after coding abstinence as 1 and non-abstinence as 0) after the model accounts for complexities in the data, such as the repeated measures of the data, imbalances in group sizes, and assumptions regarding error correlation, random effects, fixed effects.
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: A mixed effects logistic regression model included all participants who provided data for at least 1 time point. Numbers providing data at each individual time point and predicted proportions produced by the model are reported below.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Active AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline | .256 proportion of participants abstinent |
| Active AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 4 | .273 proportion of participants abstinent |
| Active AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 8 | .291 proportion of participants abstinent |
| Active AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 16 | .334 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 16 | .335 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Baseline | .322 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 8 | .328 proportion of participants abstinent |
| Minimal AAT-App | Proportion of Past-Week Complete Abstinence at Post-Intervention and Follow Up Assessments | Week 4 | .325 proportion of participants abstinent |
Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP)
3 items will be adapted from the Australian Treatment Outcomes Profile (ATOP) assessing psychological health, physical health, and overall quality of life over the past 28 days. Each item will be rated on a scale from zero to ten, where zero is poor and ten is good. Each rating will be treated as a separate variable in analyses (i.e., no composite score will be derived from the 3 separate items).
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, 16 weeks after commencing app use.
Population: Linear mixed-effects models tested all time points in a single model for each of the 3 ATOP scores. These numbers reflect the number of participants who provided data for at least one time point. Predicted marginal means and numbers of participants providing data at each individual time point are presented below
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline psychological wellbeing | 4.912 units on a scale | Standard Error 0.312 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 psychological wellbeing | 4.920 units on a scale | Standard Error 0.277 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 psychological wellbeing | 4.928 units on a scale | Standard Error 0.284 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 psychological wellbeing | 4.944 units on a scale | Standard Error 0.403 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline physical wellbeing | 5.300 units on a scale | Standard Error 0.333 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 physical wellbeing | 5.341 units on a scale | Standard Error 0.304 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 physical wellbeing | 5.382 units on a scale | Standard Error 0.311 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 physical wellbeing | 5.464 units on a scale | Standard Error 0.416 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline quality of life | 5.708 units on a scale | Standard Error 0.329 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 quality of life | 5.807 units on a scale | Standard Error 0.303 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 quality of life | 5.905 units on a scale | Standard Error 0.31 |
| Active AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 quality of life | 6.102 units on a scale | Standard Error 0.407 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 quality of life | 5.739 units on a scale | Standard Error 0.296 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline psychological wellbeing | 4.709 units on a scale | Standard Error 0.304 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 physical wellbeing | 5.124 units on a scale | Standard Error 0.296 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 psychological wellbeing | 4.926 units on a scale | Standard Error 0.269 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 quality of life | 5.483 units on a scale | Standard Error 0.295 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 8 psychological wellbeing | 5.144 units on a scale | Standard Error 0.268 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 physical wellbeing | 5.435 units on a scale | Standard Error 0.379 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 psychological wellbeing | 5.578 units on a scale | Standard Error 0.364 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 16 quality of life | 6.251 units on a scale | Standard Error 0.371 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline physical wellbeing | 4.814 units on a scale | Standard Error 0.325 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Baseline quality of life | 5.227 units on a scale | Standard Error 0.322 |
| Minimal AAT-App | Scores for Quality of Life and Health Items on the Australian Treatment Outcomes Profile (ATOP) | Week 4 physical wellbeing | 4.969 units on a scale | Standard Error 0.296 |
Severity of Dependence Scale (SDS) Scores
The Severity of Dependence Scale (SDS) is a validated, 5-item scale, with each item scored 0-3. Total scores are calculated by summing individual item scores. Higher scores indicate more severe psychological dependence on the drug being enquired about (i.e., alcohol in this study)
Time frame: Baseline, 4 weeks after commencing app use, 8 weeks after commencing app use, and 16 weeks after commencing app use
Population: A linear mixed model included all participants who provided valid data for at least one time point. Estimated marginal means and numbers providing data at each specific time point are reported below
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Severity of Dependence Scale (SDS) Scores | Baseline | 7.989 score on a scale | Standard Error 0.564 |
| Active AAT-App | Severity of Dependence Scale (SDS) Scores | Week 4 | 7.404 score on a scale | Standard Error 0.505 |
| Active AAT-App | Severity of Dependence Scale (SDS) Scores | Week 8 | 6.819 score on a scale | Standard Error 0.518 |
| Active AAT-App | Severity of Dependence Scale (SDS) Scores | Week 16 | 5.649 score on a scale | Standard Error 0.722 |
| Minimal AAT-App | Severity of Dependence Scale (SDS) Scores | Week 16 | 5.085 score on a scale | Standard Error 0.654 |
| Minimal AAT-App | Severity of Dependence Scale (SDS) Scores | Baseline | 8.752 score on a scale | Standard Error 0.551 |
| Minimal AAT-App | Severity of Dependence Scale (SDS) Scores | Week 8 | 6.919 score on a scale | Standard Error 0.49 |
| Minimal AAT-App | Severity of Dependence Scale (SDS) Scores | Week 4 | 7.836 score on a scale | Standard Error 0.49 |
Total Scores on the Alcohol Use Disorders Identification Test (AUDIT)
The Alcohol Use Disorders Identification Test (AUDIT) is a validated, 10-item scale, with each item scored 0-4. Total scores are calculated based on the sum of individual item scores. Given the AUDIT usually enquires about drinking and related problems in the past year, wording of instructions and questions was modified to ask participants to base answers on the past 3 months so that equivalent, non-overlapping periods were assessed at both baseline and the final follow-up.
Time frame: Baseline and 16 weeks after commencing app use
Population: A linear mixed model included all participants providing scores at baseline and/or follow-up. Estimates marginal means, and numbers of participants providing data at each time point, are provided below.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active AAT-App | Total Scores on the Alcohol Use Disorders Identification Test (AUDIT) | Baseline | 26.897 score on a scale | Standard Error 1.296 |
| Active AAT-App | Total Scores on the Alcohol Use Disorders Identification Test (AUDIT) | Week 16 | 14.028 score on a scale | Standard Error 1.674 |
| Minimal AAT-App | Total Scores on the Alcohol Use Disorders Identification Test (AUDIT) | Baseline | 26.250 score on a scale | Standard Error 1.279 |
| Minimal AAT-App | Total Scores on the Alcohol Use Disorders Identification Test (AUDIT) | Week 16 | 13.796 score on a scale | Standard Error 1.495 |