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Trial registered on ANZCTR


Registration number
ACTRN12620000111976
Ethics application status
Approved
Date submitted
16/01/2020
Date registered
7/02/2020
Date last updated
7/02/2020
Date data sharing statement initially provided
7/02/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of systematically developed health warning labels for alcohol containers on drinking intentions and behaviours among Australian adult regular drinkers.
Scientific title
Effects of systematically developed health warning labels for alcohol containers on drinking intentions and behaviours among Australian adult regular drinkers: randomized controlled trial.
Secondary ID [1] 298362 0
NHMRC#1129002
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Alcohol-related harm 313021 0
Condition category
Condition code
Public Health 311531 311531 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The study intervention includes five different scenarios for health warnings on alcohol containers that will be shown to study participants in a series of online questionnaires. Participants will be randomly assigned to one of five warning label conditions: two control groups that represent the usual situation (A) no warning label; and (B) alcohol industry-funded Social Aspect/Public Relation Organisation DrinkWise warning labels; or systematically developed (C) text-only warning labels; (D) text & pictogram warning labels; and (E) text & photograph warning labels.

The online study will be accessed individually by participants (via a web link in an email invitation) at a time and location of their convenience. The nine-minute Time 1 questionnaire will include the warning label intervention whereby participants are exposed to images of 24 alcohol containers, through a series of eight choice tasks. For each task, participants will view three images of popular alcohol brands and asked to select the drink that is most appealing to them (or they can select 'none appeal to me'). With the exception of the 'no warning label control' condition, the three alcoholic drinks shown in each task will feature the same warning label, so that participants in the three intervention conditions will be exposed to eight warning labels over the course of the eight tasks and participants in the DrinkWise Control Condition will be exposed to each of the four DrinkWise labels twice over the course of the eight tasks. In addition, each day for eight days after initial exposure in the Time 1 questionnaire, participants will be emailed a weblink to view a single image of an alcohol container online, with the brand and warning label varying each day (per their assigned condition). After viewing the image, participants will be asked to rate how appealing they find the image (the task will take less than one minute per day); these responses (or lack thereof) will serve as the primary measure of whether or not participants were exposed to a given image. Participants will then be invited to complete the five-minute Time 2 questionnaire nine days after completion of the Time 1 questionnaire, during which they will be asked about their drinking behaviours over the past week and future drinking intentions. To encourage completion of all stages of the project, participants will receive appropriate incentives (earn points they can redeem as shopping vouchers) according to current online research rates and email reminders if they are yet to complete a stage.

The image stimuli were designed professionally for the study. The content and format of the intervention warning labels has been systemically developed through past research projects, and the DrinkWise warning labels are currently available for voluntary use by beverage manufacturers. To increase the relevance of the task, participants in all five conditions will initially be asked to select their preferred alcohol type (beer, wine or spirits) and will only be shown images of their preferred product.
Intervention code [1] 314603 0
Behaviour
Intervention code [2] 314604 0
Lifestyle
Intervention code [3] 314605 0
Prevention
Comparator / control treatment
There are two comparator/control groups for this study.
Participants assigned to (A) no warning label (Control) will be exposed to images of alcohol containers with no health warnings, while participants assigned to (B) DrinkWise warning labels (Control) will be exposed to images of alcohol containers with the current voluntary warning labels recommended by DrinkWise.
Both control treatments will be provided using the same mode and frequency as the intervention treatments.
Control group
Active

Outcomes
Primary outcome [1] 320335 0
Proportion of participants indicating intentions to reduce alcohol consumption in the next month.

Participants will be asked how likely they are to do the following in the next month: a) reduce how often you drink alcohol and b) reduce the amount of alcohol you have on each drinking occasion.

These questions were adapted from Wakefield M et al (2018). A composite outcome will be calculated by combining the items so that participants who answer ‘definitely/probably will’ for either or both of the original variables will be classified as ‘definitely/probably will’ in the combined variable and only those who responded ‘definitely/probably will not’ to both original variables will be coded as ‘definitely/probably will not’ in the combined variable.

Reference: Wakefield MA, Brennan E, Dunstone K, Durkin SJ, Dixon HG, Pettigrew S, Slater MD. Immediate effects on adult drinkers of exposure to alcohol harm reduction advertisements with and without drinking guideline messages: experimental study. Addiction 2018; 113(6): 1019-29.
Timepoint [1] 320335 0
Time 1 questionnaire: after all eight drink choice tasks are completed (primary timepoint); And the Time 2 questionnaire, nine days after completion of the Time 1 questionnaire.
Primary outcome [2] 320338 0
Proportion of participants indicating intentions to avoid alcohol in the next month.

Participants will be asked how likely they are to avoid drinking alcohol completely in the next month .This question was adapted from Wakefield M et al (2018).

Reference: Wakefield MA, Brennan E, Dunstone K, Durkin SJ, Dixon HG, Pettigrew S, Slater MD. Immediate effects on adult drinkers of exposure to alcohol harm reduction advertisements with and without drinking guideline messages: experimental study. Addiction 2018; 113(6): 1019-29.
Timepoint [2] 320338 0
Time 1 questionnaire: after all eight drink choice tasks are completed (primary timepoint); And the Time 2 questionnaire, nine days after completion of the Time 1 questionnaire.
Primary outcome [3] 320339 0
Proportion of participants engaging in in alcohol-limiting drinking behaviours.

Participants will be asked if they did any of the following when drinking alcohol in the past week: a) counted the number of drinks you had, b) drank slowly rather than gulping or sculling, c) avoided trying to “keep up” or “out-drink” others, d) decided not to exceed a certain number of drinks, e) refused an alcoholic drink you were offered because you really didn’t want it, f) drank more than you had intended to on an occasion, and g) drank an alcoholic drink you were offered even when you didn’t really want it.

These items were adapted from the Australian Institute for Health and Welfare's 2016 National Drug Strategy Household Survey and Dekker MR (2018). A composite score will be calculated by summing the 'yes' responses.

References: Australian Institute of Health and Welfare. National Drug Strategy Household Survey 2016: detailed findings. Drug Statistics series no. 31. AIHW: Canberra, Australia, 2017. Available from: https://www.aihw.gov.au/getmedia/15db8c15-7062-4cde-bfa4-3c2079f30af3/21028a.pdf.aspx?inline=true (Archived at http://www.webcitation.org/6wYJ4L8tf).

Dekker MR, Jongenelis MI, Wakefield M, Kypri K, Hasking P, Pettigrew S. A longitudinal examination of protective behavioral strategies and alcohol consumption among adult drinkers. Addict Behav 2018; 87: 1-7.
Timepoint [3] 320339 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [1] 371321 0
Proportion of participants indicating that none of the drinks appeal to them across the eight drink choice tasks.

In each of the eight drink choice tasks, participants will be exposed to images of three alcohol containers featuring warning labels (per their assigned condition) and participants will be asked "which of the three drinks is most appealing to you" or if "none appeal to me". This measure was designed specifically for the study.
Timepoint [1] 371321 0
Time 1 questionnaire: Immediately following each of the eight drink choice tasks.
Secondary outcome [2] 371322 0
Proportion of participants who intend to try and drink less alcohol in the next week.

Participants will be asked how likely they are to try and drink less alcohol in the next week on a four-point Likert scale. This measure was designed specifically for this study.
Timepoint [2] 371322 0
Time 1 questionnaire: after all eight drink choice tasks are completed; And the Time 2 questionnaire, nine days after completion of the Time 1 questionnaire.
Secondary outcome [3] 371323 0
Proportion of participants indicating intentions to increase alcohol consumption in the next month.

Participants will be asked how likely they are to do the following in the next month: a) increase how often you drink alcohol, and b) increase the amount of alcohol you have on each drinking occasion.

These questions were adapted from Wakefield et al (2018). A composite outcome will be calculated so that participants who answer ‘definitely/probably will’ for either or both of the original variables will be classified as ‘definitely/probably will’ in the combined variable and only those who responded ‘definitely/probably will not’ to both original variables will be coded as ‘definitely/probably will not’ in the combined variable.

Reference: Wakefield MA, Brennan E, Dunstone K, Durkin SJ, Dixon HG, Pettigrew S, Slater MD. Immediate effects on adult drinkers of exposure to alcohol harm reduction advertisements with and without drinking guideline messages: experimental study. Addiction 2018; 113(6): 1019-29.
Timepoint [3] 371323 0
Time 1 questionnaire: after all eight drink choice tasks are completed; And the Time 2 questionnaire, nine days after completion of the Time 1 questionnaire.
Secondary outcome [4] 371324 0
Participants’ mean number of standard drinks consumed in the past seven days.

The validated 7-Day Timeline Followback measure was sourced from Sobell LC and Sobell MB (1995).

Reference: Sobell LC, Sobell MB. Alcohol Consumption Measures. In: Allen J. P. and Columbus M. (Eds). Assessing alcohol problems: A guide for clinicians and researchers. Bethesda, Maryland: National Institute on Alcohol Abuse and Alcoholism, 1995, pp. 55-74.
Timepoint [4] 371324 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [5] 371325 0
Participants’ mean score on alcohol contemplation ladder.

The validated scale was sourced from Kersbergen et al (2017).

Reference: Kersbergen I, Field M. Alcohol consumers’ attention to warning labels and brand information on alcohol packaging: Findings from cross-sectional and experimental studies. BMC Public Health 2017; 17(1): 123.
Timepoint [5] 371325 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [6] 371326 0
Proportion of participants who thought about the health risks associated with drinking alcohol in the past week.

This measure was adapted from a question in the International Tobacco Control Four-Country Survey which asked about warning labels increasing thoughts of health risks of smoking.

Reference: Yong, H. H., Borland, R., Thrasher, J. F., Thompson, M. E., Nagelhout, G. E., Fong, G. T., & Hammond, D. (2014). Mediational pathways of the impact of cigarette warning labels on quit attempts. Health Psychology, 33(11), 1410-1420. doi: http://dx.doi.org/10.1037/hea0000056.
Timepoint [6] 371326 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [7] 371327 0
Proportion of participants aware of health risks.

To be assessed using a five-item measure adapted from previous research used to assess the impact of warning labels on sugar sweetened beverages (Roberto CA et al, 2016).

Reference: Roberto, C. A., Wong, D., Musicus, A., & Hammond, D. (2016). The influence of sugar-sweetened beverage health warning labels on parents’ choices. Pediatrics, 137(2), e20153185.
Timepoint [7] 371327 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [8] 371328 0
Proportion of participants who have conversations with other people to discuss the health warnings.

To be assessed using a two-item measure adapted from previous research used to assess the impact of warning labels on tobacco products (Morgan et al, 2017).

Reference: Morgan, J. C., Southwell, B. G., Noar, S. M., Ribisl, K. M., Golden, S. D., & Brewer, N. T. (2017). Frequency and content of conversations about pictorial warnings on cigarette packs Nicotine & Tobacco Research. doi: https://doi.org/10.1093/ntr/ntx180
Timepoint [8] 371328 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [9] 371959 0
Proportion of participants who have conversations with other people to discuss the health risk associated with alcohol.

To be assessed using one question adapted from previous research used to assess the impact of warning labels on tobacco products (Morgan et al, 2017).

Reference: Morgan, J. C., Southwell, B. G., Noar, S. M., Ribisl, K. M., Golden, S. D., & Brewer, N. T. (2017). Frequency and content of conversations about pictorial warnings on cigarette packs Nicotine & Tobacco Research. doi: https://doi.org/10.1093/ntr/ntx180
Timepoint [9] 371959 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.
Secondary outcome [10] 371960 0
Support for labels with information about alcohol-related risks on alcohol containers.

To be assessed using one item, adapted from previous research assessing the impact of sugar tax (Reynolds et al., 2018).

Reference: Reynolds, J. P., Pilling, M., & Marteau, T. M. (2018). Communicating quantitative evidence of policy effectiveness and support for the policy: Three experimental studies. Social Science & Medicine, 218, 1-12. doi:https://doi.org/10.1016/j.socscimed.2018.09.037
Timepoint [10] 371960 0
Time 2 questionnaire: nine days following initial exposure to warning label stimuli in the Time 1 questionnaire drink choice tasks, and eight days of potential repeated exposure to warning label stimuli.

Eligibility
Key inclusion criteria
Australian adults aged 18-69 years.
Consumed alcohol at least weekly over the past 12 months.
Provide informed consent.
Minimum age
18 Years
Maximum age
69 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Currently work, or close family or friends work, in health promotion, market research, marketing or advertising, or in the alcohol industry (note: does not include those who work in hospitality).
Demographic quotas based on age and sex will be used. Participants will be excluded if the quota bracket which they belong in has been filled.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is concealed. At the commencement of the online Time 1 questionnaire, following confirmation of participants' study eligibility, participants will be randomly assigned to a warning label condition using permuted block randomisation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Allocation to warning label condition will be random for all participants (no age/gender quotas) using permuted block randomisation. Blocking is used to ensure that there is a close balance of the number of participants in each condition throughout recruitment. The sequence of condition allocation within each block will be at random.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Based on past research studies, we hypothesise exposure to the systematically developed warning labels (text-only, text & pictograph, text & photograph) will be associated with (i) greater intentions to reduce or avoid alcohol immediately post-exposure (Pettigrew et al, 2016) and (ii) engaging in alcohol-limiting behaviours in the following week (Wakefield et al, unpublished data), compared to each control (no warning label or DrinkWise warning labels). To detect similar magnitudes of difference to what was observed for these studies, we would require 364 participants per condition to complete the Time 2 questionnaire, with power of 0.90 (at alpha=0.05). To account for participants dropping out of the project throughout the ten-day contact period, we will be recruiting a total N=2600 at Time 1.

Preliminary analyses will assess if the distribution of the Time 1 demographic and alcohol consumption variables vary across conditions. Binary primary and secondary outcomes will be analysed using logistic regression, while continuous primary and secondary outcomes will be analysed using linear regression. We will estimate four models for each outcome to assess the effectiveness of the systematically developed warning labels (text-only, text & pictogram, text & photograph). In the first model, the no warning label control condition will be the referent, and in the second model the DrinkWise warning label control condition will be the referent; these models will test differences between the text-only, text & pictogram, text & photograph warning label conditions and the two different control referent conditions. In the third model the referent will be changed to the text-only warning label condition and test differences against the text & pictogram, text & photograph warning label conditions. The fourth model will change the referent to the text & pictogram warning label condition and test differences between the text & photograph warning label condition. All models will include the full sample. A p-value of 0.01 or less will be deemed to indicate a significant finding due to the large number of comparisons.

References: Pettigrew S, Jongenelis MI, Glance D, Chikritzhs T, Pratt IS, Slevin T, Liang W, Wakefield M. The effect of cancer warning statements on alcohol consumption intentions. Health Education Research 2016; 31: 60-69.
Wakefield MA, Brennan E, Dunstone K, Durkin SJ, Dixon HG, Pettigrew S, Slater MD. Unpublished data from the study described in Addiction 2018; 113(6): 1019-29, Immediate effects on adult drinkers of exposure to alcohol harm reduction advertisements with and without drinking guideline messages: experimental study.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 302900 0
Government body
Name [1] 302900 0
National Health and Medical Research Council (NHMRC)
Address [1] 302900 0
Level 1, 16 Marcus Clarke Street
Canberra ACT 2601
Country [1] 302900 0
Australia
Primary sponsor type
Individual
Name
Professor Melanie Wakefield
Address
Centre for Behavioural Research in Cancer
Cancer Council Victoria
615 St Kilda Road
Melbourne VIC 3004
Country
Australia
Secondary sponsor category [1] 302854 0
None
Name [1] 302854 0
Address [1] 302854 0
Country [1] 302854 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 303471 0
Cancer Council Victoria Institutional Research Review Committee
Ethics committee address [1] 303471 0
Cancer Council Victoria
615 St Kilda Road
Melbourne VIC 3004
Ethics committee country [1] 303471 0
Australia
Date submitted for ethics approval [1] 303471 0
10/05/2019
Approval date [1] 303471 0
01/07/2019
Ethics approval number [1] 303471 0
IER 1609

Summary
Brief summary
Alcohol use ranks among the top five contributors to global disease burden, yet the public has relatively poor awareness of the wide range and seriousness of alcohol-related harms. Following successful use in tobacco control, health warnings on alcohol containers have been proposed as a potential alcohol harm reduction measure. This study aims to investigate the efficacy of alcohol health warning labels on drinking intentions and behaviours among Australian adults who drink alcohol regularly. Additionally, the study aims to investigate the degree to which the format of the warning labels influence health warning efficacy. The five alternative warning label scenarios to be tested via the online experiment include: two control groups that represent the usual situation (A) no warning label; and (B) DrinkWise voluntary warning labels; and systematically developed (C) text-only warning labels; (D) text & pictogram warning labels; and (E) text & photograph warning labels. The findings from this study will contribute to the evidence base available for advocacy and forthcoming policy deliberations on alcohol warning labels.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 93774 0
Prof Melanie Wakefield
Address 93774 0
Centre for Behavioural Research in Cancer
Cancer Council Victoria
615 St Kilda Road
Melbourne VIC 3004
Country 93774 0
Australia
Phone 93774 0
+61 3 9514 6351
Fax 93774 0
Email 93774 0
Melanie.Wakefield@cancervic.org.au
Contact person for public queries
Name 93775 0
Prof Melanie Wakefield
Address 93775 0
Centre for Behavioural Research in Cancer
Cancer Council Victoria
615 St Kilda Road
Melbourne VIC 3004
Country 93775 0
Australia
Phone 93775 0
+61 3 9514 6351
Fax 93775 0
Email 93775 0
Melanie.Wakefield@cancervic.org.au
Contact person for scientific queries
Name 93776 0
Prof Melanie Wakefield
Address 93776 0
Centre for Behavioural Research in Cancer
Cancer Council Victoria
615 St Kilda Road
Melbourne VIC 3004
Country 93776 0
Australia
Phone 93776 0
+61 3 9514 6351
Fax 93776 0
Email 93776 0
Melanie.Wakefield@cancervic.org.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
No, individual participant data will not be available. Output will be disseminated in peer reviewed publications by the research team.
What supporting documents are/will be available?
No other documents available
Summary results
No Results