Table 1 Alcohol reduction apps evaluated in the peer reviewed literature

Alcooquizz [22]

Individuals in the general population with unhealthy alcohol use

Study design: Pilot RCT

Participants: 977 participants with unhealthy alcohol use recruited online

Intervention group: 416 participants offered the Alcooquizz app for download. Alcoquizz app contains five active components, including providing personalised feedback, a self-monitoring tool, a designated driver tool, eBAC calculator, and fact sheets on alcohol use and its consequences

Control group: 516 participants not offered any intervention

Follow-up: 6 months

No significant difference in reported SD consumed/week between intervention and control group at 6-months–IRR 0.93 (95% CI 0.84, 1.03)

In a per protocol analysis where participants in the intervention group who did not actually download the app were excluded the difference in SD/week at 6 months was significant – IRR 0.88 (95%CI = 0.78, 0.99)

Availability: Free to download in Australian, NZ, US, UK, Irish, Canadian and Swiss iTunes stores. Unable to find app in any Google Play stores

Drink less [23, 34]

Individuals in the general population who drink excessively

Study design: 2⁵ Factorial RCT to evaluate the five intervention components (modules) of the app

Participants: Original trial of 672 participants living in the UK who downloaded the app in a commercial app store and reported drinking excessively [23]. Subsequently, extended recruitment of an additional 1914 participants occurred and all the data were analysed [34]. Total sample size was 2586 but only 342 (13.2%) completed follow-up.

Intervention: The Drink Less app is centered around alcohol reduction goal setting with five independent intervention modules: normative feedback, cognitive bias re-training, self-monitoring and feedback, action planning, and identity change

Participants were randomly assigned different versions of the app with different combinations of either “enhanced” or “minimal functionality” of the five modules (active components were removed in the minimal functionality versions, which acted as the control)

Follow-up: 4-weeks

Results indicated that there are no large main effects of the enhanced version of individual components on SD/week (0.22 < BF < 0.83) or AUDIT score (0.14 < BF < 0.98) compared to minimal versions

In an additional exploratory analysis, participants receiving four of the enhanced components averaged a greater reduction in SD/week than those not receiving any (21.6 versus 12.1 SDs), but the data were insensitive (BF = 1.42)

Availability: Only available for download in UK iTunes store (free). Unable to find app in iTunes stores in other countries, or in any Google Play stores

Drinkaware [26]

Individuals in the general population who want to reduce their alcohol consumption

Study design: Mixed-methods sequential explanatory design

Intervention: Drinkaware app has four main features: calculate units of alcohol and energy in drinks and track consumption; information about the impacts of drinking on health; set goals; define geographical locations that may be triggers where support may be required

Quantitative: Usage data from 119,713 individuals who downloaded the app over a 13-month period analysed. Additional analysis performed on 12-weeks of usage data of a sub-set of 3401 (2.8%) ‘engaged users’

Qualitative: of the 119,713 users 3491 who had supplied contact details within the app were sent a feedback survey. 189 of these users completed the survey, and of these 21 were recruited for in-depth interview.

Quantitative findings: ‘Engaged users’ self-reported a reduction in alcohol consumption over time, but almost all of the change occurred in the first week after downloading the app (reduction of 4.9 units after 1 week, P < 0.05) then consumption plateaued

Qualitative findings: Mixed feedback received regarding each individual app feature, although there was a common preference for more personalised content

Availability: Only available for download in UK iTunes store (free). Unable to find app in iTunes stores in other countries, or in any Google Play stores

Daybreak [30]

Individuals in the general population drinking at risky levels

Study design: Originally designed as RCT but due to technical errors there was no control group

Participants: 793 participants in the general population who accessed the Daybreak app and reported AUDIT scores > 7. Half were originally intended to also receive online coaching via real-time chat messages, with the non-coaching group acting as controls. However, due to a technical error some controls could also access the coaching so the main analysis comprised all participants

Intervention: Daybreak program aims to assist users to change their relationship with alcohol with four main features: weekly check-ins, peer support, behavioural experiments and health coaching

Follow-up: 1 month and 3 months

Reductions in AUDIT-C scores from a mean of 9.1 to 5.8 (P < 0.001) at 3-months follow-up

Accessing online coaching was not associated with improved outcomes.

Availability: Available free on the Australian iTunes and Google Play stores. 21-day free trial available in iTunes and Google Play stores from other countries, and at a cost after the trial period

Self-Record (Jibun Kiroku) [31]

Full-time workers experiencing mild to moderate psychological distress

Study design: Non-randomised pilot study with control group

Participants: 557 Japanese full-time workers aged 20-59 years who were experiencing mild to moderate psychological distress (Kessler Psychological Distress Scale score between 5 and 12), who indicated an interest in self-monitoring smartphone apps. Recruited by a research and marketing company

Intervention group: 306 participants who self-selected to the intervention group by agreeing to use to the Self Record app. The Self Record app was designed primarily to improve psychological distress, not to reduce alcohol consumption. However, the authors expected that a reduction in psychological distress would lead to reduction in alcohol consumption so tested this, in addition to measuring changes in psychological distress. The app focuses on self-monitoring and awareness of negative thoughts, daily activities, and daily mood, and provides psychoeducation

Control group: 251 participants who did not agree to use the Self Record app. Given only baseline and follow-up surveys, nothing else

Follow-up: 4 weeks

Intention-to-treat analysis alcohol outcomes: Participants in the intervention group reported increased typical drinking (η² = 0.009) and heavy drinking (η² = 0.001) compared to controls over the study period. The effect size was small but significant

Per-protocol analysis alcohol outcomes: After excluding participants who discontinued using the app after the first day (65% of intervention group) and those who incorrectly answered a validity check item (65% of all participants), results still showed that the intervention group reported significantly increased typical drinking (η² = 0.005), and heavy drinking (η² = 0.007) compared to those in the control group

Availability: Unable to find app in any iTunes or Google Play stores

Cue exposure therapy (CET) [32]

Designed as aftercare for individuals who have recently completed an outpatient alcohol treatment program

Study design: Investigator-blinded parallel RCT

Participants: 164 participants were recruited at the end of a 3-month primary treatment program for AUD at an outpatient alcohol treatment clinic in Denmark. Aimed to compare aftercare treatment approaches

CET therapy group: 54 participants randomised to receive group CET therapy with urge-specific coping skills (USCS), conducted by a therapist for 4 × 2 h sessions over 8 weeks. CET with USCS aims to teach coping skills to reduce cravings, which individuals the practise when exposed to cues to induce cravings

CET app group: 54 participants randomised to receive then CET app, which is based on the same treatment principles as the CET with USCS therapy, transformed into a fully automated mobile phone app. The app contained alcohol exposure videos which imitated sessions with a therapist

Control group: 56 participants received aftercare as usual, which included 1 × 1 h individual session 8 weeks after the completion of the treatment program

Follow-up: 2 and 6 months

No significant differences were found between the intervention groups (CET therapy group and CET app group) compared with the control group on alcohol consumption outcomes over time

Similarly, no differences were found when comparing CET therapy and CET app groups

Therefore, CET with USCS delivered as aftercare either via group sessions or a mobile phone app did not increase the effectiveness of usual aftercare for individuals with AUD

Availability: Unable to find app in any iTunes or Google Play stores

SIDEAL [27]

Acronym of Spanish words = Innovative Support to the Alcohol Dependent Patient

Individuals with alcohol dependence being treated in an outpatient setting

Study design: Pilot study with no control group. Aimed to assess the app’s usability and efficacy at reducing alcohol consumption

Participants: 24 participants being treated for alcohol dependence as outpatients

Intervention: All participants received the SIDEAL app plus treatment as usual. The SIDEAL app was developed with MI as its theoretical foundation and has six main functionalities: consumption register; pharmacological adherence register; calendar and reminder system for treatment appointments; medical information and psychoeducation on alcohol dependence; questionnaires (addressing cravings, progress etc.); feedback

Follow-up: 6-week trial

Reported BD days reduced from 25.5 days in the 6-weeks prior to 5.8 days during the 6-week study period (P < 0.001). SD consumed/day also reduced from 6.5 to 1.9 SD/day (P < 0.001)

Availability: Unable to find app in any iTunes or Google Play stores

A-CHESS Addiction– Comprehensive Health Enhancement Support System [25]

Designed to improve continuing care in adults with alcohol use disorders

Study design: Unmasked RCT

Participants: 349 participants leaving residential care who met criteria for DSM-IV alcohol dependence when they entered residential treatment

Intervention group: 170 participants given treatment as usual plus a smartphone with the A-CHESS app installed for 8-months, followed by a 4-month period with treatment as usual only. The A-CHESS app has its theoretical basis in self-determination theory, aiming to improve its users’ competence, social relatedness, and motivation

Control group: 179 participants leaving residential care given treatment as usual only for 12 months

Follow-up: 4, 8 and 12 months

Across the 3 follow-up periods there were significantly fewer risky drinking days (days when > 4 SD for men and > 3 SD for women consumed in under 2 h) on average reported in the intervention group compared to control (1.39 vs 2.75 days/month, P = 0.003)

Participants in the intervention group were also more likely than controls to report abstinence at all 3 follow-up points (P = 0.03)

Availability: Available to download in Australian, NZ, US, UK, Irish, Canadian and Swiss iTunes stores but a provider code/login is needed. Unable to find app in any Google Play stores

CASA-CHESS (A-CHESS translated and adapted for Latinx Spanish-speakers) [33]

Designed to improve continuing care in adults with alcohol use disorders.

Study design: Single group pre-post study. No control group

Participants: 79 Spanish-speaking participants leaving a residential alcohol and other drug treatment program in the north eastern USA. Authors separated participants into two subgroups for the analysis based on how long they used the CASA-CHESS app for – > 4 months (n = 58) or < 4 months (n = 21) – and compared the outcomes in their analysis

Intervention: All participants were given treatment as usual plus an Android smartphone equipped with the CASA-CHESS app installed for 8-months. The CASA-CHESS app was developed by adapting A-CHESS (described above) to be linguistically and culturally relevant for Latinx Spanish-speaking adults in recovery for alcohol or other drug use disorders

Follow-up: Baseline data (leaving residential care) was compared to 6 month follow-up

Alcohol-related outcomes: Alcohol use did not differ significantly between baseline and 6 months for the overall sample (P = 0.219), or between baseline and 6 months for either of the subgroups (> 4 months, P = 0.625 and < 4 months P = -). Logistic regression analyses examining between subject effects for the > 4 months and < 4 months subgroups also found no significant difference in alcohol use between the groups

Availability: Unable to find app in any iTunes or Google Play stores

SoberDiary [28]

Individuals recovering from alcohol dependence undergoing outpatient treatment

Study design: Hybrid effectiveness-implementation design

Participants: 38 participants undergoing an outpatient program for alcohol dependence

Intervention: All participants given the SoberDiary system, which consists of an app coupled to a bluetooth breathalyser that measures the BrAC. The app contains four functional modules: alcohol use detection; feedback on progress; a self-fulfilment guide; and skills enhancement (managing cravings, high-risk situations etc.)

19 participants were classified as highly adherent (HA) and 19 as less adherent (LA), according their total usage of SoberDiary system throughout the study period. These groups were compared

Follow-up: Followed-up at 1, 2, 4, 8, and 12 weeks

Better compliance in the using the app was associated with better outcomes in some of the measured drinking outcomes

HA participants recorded significantly fewer drinking days/week and SD consumed/week, a higher cumulative number of abstinence days and a higher abstinence rate compared to the LA group. No significant differences observed in the number of heavy drinking days/week, number of drinks per drinking day or the time to relapse

Availability: Unable to find app in any iTunes or Google Play stores

LBMI-A (Location-Based Monitoring and Intervention for Alcohol Use Disorders) [24]

Developed for use in people with alcohol use disorder

Study design: Pilot study (not randomised) with intervention and control group

Participants: 60 participants who met DSM-V criteria for an alcohol use disorder and were motivated to change their drinking recruited using flyers, radio and newspaper advertisements

Intervention group: 31 participants were given the LBMI-A app. The app consists of seven psychoeducation modules each with corresponding practical tools, including modules aimed at managing cravings, providing feedback, and improving problem-solving and drink refusal skills

Comparison group: 29 participants given a single Internet-based brief motivational intervention, plus an information booklet on the health consequences of alcohol consumption

Follow-up: 6-weeks

Only the LBMI-A group experienced a statistically significant increase in percent days abstinent over the 6-weeks (P < 0.001) the comparison group did not (P = 0.324)

Both groups reported statistically significant decreases in SD/week and heavy drinking days at 6-weeks compared to baseline figures

Availability: The original LBMI-A app is not available in any iTunes or Google Play stores, however, a revised version of the app called Step Away can be accessed through the Australian, NZ, US, UK, Irish and Canadian iTunes stores. Unable to find Step Away app in Google Play stores

HealthCall-S [29]

Developed for use by alcohol dependent individuals living with HIV

Study design: RCT pilot study

Participants: 47 participants living with HIV who had used non-injecting drugs ≥ 4 days and binge drank at least once in the previous 30 days, recruited via ads in newspapers and pamphlets in waiting rooms

Intervention group: 23 participants given MI + HealthCall-S app at baseline, then brief MI booster session at 30 and 60 days. The HealthCall-S app is an adaption of a previously trialled interactive voice response resource (HealthCall-IVR). HealthCall is based on 3 main aspects: self-monitoring, positive reinforcement and personalised feedback

Control group: 24 participants given MI at baseline and brief booster session at 30 and 60 days

Follow-up: 30 days and 60 days

Alcohol-related outcomes: Reductions in the number of drinking days and mean SD/day in the previous month were greater in the intervention group compared to controls at 60-days follow-up but this difference was not significant (P = 0.09 and P = 0.11 respectively)

Other drug-related outcomes did show significantly greater reductions in the intervention group compared to controls

Availability: Unable to find app in any iTunes or Google Play stores

Ray’s Night Out [15]

Designed to increase alcohol knowledge and reduce alcohol use in young people

Study design: RCT comparing immediate versus 1-month delayed-access to app

Participants: 197 participants aged 16 to 25 years who drank alcohol in the previous month recruited through university student emails and youth relevant websites

Intervention group: 101 participants given immediate access to the Ray’s Night Out app, which centres around a red panda avatar called Ray who users take on a virtual night out and are provided with information about the consequences of drinking and strategies for managing alcohol consumption. The aim is that users will gain knowledge, motivation and skills and reduce their alcohol consumption

Control group: 96 participants given delayed-access to the Ray’s Night Out app after 1 month

Follow-up: 1, 2, 3 and 6 months

No significant differences in alcohol use measures or related harms were found

Participants in the immediate access group achieved an increase in alcohol knowledge (measured using 16-item questionnaire, scores ranging 0 to 16) at 1-month follow-up compared to baseline (mean difference = 0.90, 95% CI: 0.49, 1.30) but the delayed-access group did not (mean difference = 0.32, 95% CI: −0.07, 0.72)

Availability: Free to download in Australian, NZ, US, UK, Irish and Canadian iTunes and Google Play stores

Promillekoll and Party Planner [14, 21]

Aims to promote safe drinking choices on party occasions among university students

Study design: RCT with two intervention groups compared to a control group

Participants: 2166 Swedish university students with hazardous drinking (AUDIT score ≥ 6 for women and ≥ 8 for men), recruited via email and Facebook followed-up for 7 weeks

Promillekoll iPhone/Android app group: 722 participants given the Promillekoll app, which contains a real-time BAC calculator and offers a number of strategies to maintain alcohol consumption below harmful levels

Party Planner web-based app group: 722 participants given the Party Planner app, which is similar to Promillekoll app with additional functionality of simulating or planning a drinking event beforehand and then comparing the simulation to the real-time event afterwards

Control group: 722 participants received no intervention or information between study registration and follow-up

Follow-up: 7-weeks. Data for a subgroup of participants with hazardous but not excessive drinking levels (n = 1157, baseline weekly drinking > 9 SD/week for women and > 14 SD/week for men) followed up at 7, 14 and 20 weeks

7-week follow-up, all participants: The only significant difference between either group and controls was that the Promillekoll group showed a higher relative risk over 7 weeks for excessive drinking in comparison to controls (OR 1.83; P <=0.01; CI = 1.02; 2.99)

7, 14, and 20-week follow-up for non-excessive drinkers: Estimated average percentage BAC levels for the week were significantly lower for both the PartyPlanner and Promillekoll groups compared to controls at 7, 14, and 20 weeks (P = 0.001 at 7,14,20-weeks for each group compared to controls). Binge drinking occasions/week were lower for the Promillekoll group compared to controls at 7-weeks (P = 0.04), 14-weeks (P = 0.022) and 20-weeks (P = 0.043), but only at 14 weeks for the PartyPlanner group compared to controls (P = 0.046)

Availability: The Promillekoll is not available in any iTunes or Google Play stores. The PartyPlanner web-based app is also no longer available on the web

TeleCoach [16]

Young people who drink excessively

Study design: Randomised trial with two intervention groups compared to a comparison group which acted as the control condition

Participants: 330 Swedish university students with excessive alcohol consumption who had participated in a previous alcohol reduction app trial [14]

Intervention: TeleCoach app consists of two main active components: tailored feedback and monitoring module with information; a skills training module with tools to reduce alcohol consumption

Immediate access group: 93 participants given immediate access to the TeleCoach app

Delayed-access group: 93 participants given access to the TeleCoach app after 6-weeks

Control group: 144 assessment-only controls with excessive alcohol consumption from a previous trial [11] were used for comparison

Follow-up: 6 and 12 weeks

During the follow-up period the odds for not having excessive weekly alcohol consumption in the immediate access group were almost twice as high as for controls (OR = 1.95, 95% CI = 1.36-2.80)

At 12 weeks follow-up the immediate access group reported significantly fewer drinking days/week (P = 0.034) compared to controls

No significant differences found in other measures (SD consumed/week, BD days/week, average eBAC/week and peak eBAC over a month)

Availability: Unable to find app in any iTunes or Google Play stores

Minimise [17]

Young people seeking to reduce their alcohol consumption

Study design: Pilot RCT

Participants: 45 participants aged 18-35 seeking to reduce their alcohol consumption recruited via social media and from ads placed at an Australian university campus

Intervention group: 25 participants received the Minimise app, which is designed to deliver a range of protective behavioural strategies tailored to the user’s drinking goal (i.e., reduce consumption or drinking-related consequences), their momentary affective state (negative/positive), and their social, interpersonal context (who they are with).

Control group: 20 participants received the InstantSurvey app (control app with only alcohol consumption-tracking functionality enabled).

Follow-up period: 28 days

No significant reductions in frequency of risky drinking occasions (≥ 5 SD in a single setting) and alcohol-related harms (e.g. physically unwell, work/study consequence) from baseline to post-intervention in either group

However, participants in the intervention group reported using protective behavioural strategies to control alcohol consumption over the past 2 weeks significantly more frequently than the controls (1.61 vs 1.07 times, P = 0.04), and to reduce alcohol-related harm when drinking significantly more frequently (1.47 vs 0.63 times, P = 0.01).

Availability: Not available on any iTunes or Google Play as the authors have taken the app down to update it

D-ARIANNA Digital-Alcohol Risk Alertness Notifying Network for Adolescents and Young Adults [18]

Young people engaging in binge drinking

Study design: Natural, quasi-experimental, pre-post test design without a control group

Participants: 590 participants aged 18-24 years recruited at pubs/clubs and music events

Intervention: All participants were asked “did you binge drink in the past two weeks?” with a yes/no response, then were assisted to download the D-ARIANNA app onto their phones and were observed by facilitators to self-administer the app modules at least once. The app estimates current risk of BD by completion of questionnaires and gives a personalised risk estimate indicating how users’ risk factors contribute to the overall score

Follow-up: Participants were phoned 14 days later and asked whether they had engaged in BD during this period. 83 of the 590 participants could not be reached

If the response from the 83 people lost to follow-up were assumed to be the same at the end of the study period as the start, then use of the app was associated with a statistically significant reduction in the proportion of participants reporting BD over the 2-week study period compared to baseline OR = 0.45 (95% CI, 0.37-0.55)

Availability: Unable to find app in any iTunes or Google Play stores.

Drinks meter [19]

Young people who are current drinkers

Study design: Pilot RCT with two intervention and two control groups.

Participants: 488 current drinkers aged 18 to 30 years recruited via social media, and posters/emails targeted at university students

Drinks Meter iPhone/Android app group: 123 participants received the Drinks Meter app, which provides users with brief screening and advice for alcohol plus normative feedback, information on calories consumed and money spent

OneTooMany web-based app group: 123 participants received a link to the OneTooMany website/web app, which presents users with a series of socially embarrassing scenarios that may occur when drinking and asks them to score themselves according to if/how recently they had been experienced

Control group 1: 121 participants were asked to imagine they were exposed to information about alcohol misuse, without actually receiving any information

Control group 2: 121 participants were asked for baseline and follow-up measures only

Follow-up: 4-weeks

The study failed to recruit and obtain sufficient follow-up data to reach a prior estimated power for detecting a difference between groups (estimated required sample size was 800, number recruited = 488, with follow-up data on 402)

Of the 402 participants sample with follow-up data there were no significant differences after 4-weeks between intervention and control groups on AUDIT-C scores, drinking harms measure via questionnaire or occasions of pre-loading (consuming alcohol at home before a night out)

Availability: Drinks Meter app is available in the US, Canadian, UK, Irish, Australian and NZ stores iTunes and Google Play stores. One Too Many is can be accessed on a web browser - http://onetoomany.co/

Once Upon a High (VoltEgySzer in Hungarian) [20]

Young people aged 14-18 years

Study design: Cluster non-randomised controlled trial

Participants: 386 students aged 14-18 years recruited from 2 vocational and 2 high schools in Hungary.

Intervention group: Students from 1 vocational school and 1 high school instructed to download the Once Upon a High app, an interactive gamified drug prevention app that contains interactive comics/cartoons and games, and information on the effects of psychoactive substances and where to find list treatment and support in Hungary

Control group: Students from 1 vocational school and 1 high school who did not download the app. Participants only completed the baseline and follow-up surveys

Follow-up: Participants completed a baseline survey and follow-up survey 2-months later. 246 students completed the 2-month follow-up (140 or 36% lost to follow-up)

Alcohol use outcome: There was no significant difference in past month alcohol use between the intervention and control groups (P = 0.014)

The only statistically significant outcome was a greater decrease in energy drink consumption after 2-months in the intervention group compared to control group

Availability: VoltEgySzer app available in Hungarian in the US, Canadian, UK, Irish, Australian, NZ and Hungarian Google Play stores. Unable to find app in any iTunes stores