Impact of altering the availability of non-alcoholic and alcoholic drinks on selection and purchasing

Plain English Summary

Background and study aims
Many people exceed the current recommended guidelines for alcohol consumption in the UK. As well as immediate health effects, drinking too much alcohol has been linked to long-term illnesses such as liver diseases (e.g. cirrhosis) and cancers (including breast cancer and bowel cancer). One promising intervention is increasing the availability of non-alcoholic drinks relative to the proportion of alcoholic drinks, which has been shown to reduce alcohol selection in online settings.
The aim of this study is to estimate the impact of altering the relative availability of a subset of drink selection options, to increase the proportion of non-alcoholic drinks (alcohol-free beer, cider and wine and soft drinks) and decreasing the proportion of alcoholic drinks (beer, cider and wine) (i.e., decreasing the number of alcohol units within the range of available products), on the number of alcohol units that are i) selected and ii) purchased online.

Who can participate?
Adults over the age of 18, who drink beer or wine at least weekly and regularly purchase alcohol online at Tesco.

What does the study involve?
Participants from the research agency's (Roots Research) panel of participants will first be contacted by email and invited to complete the initial screening questionnaire and given information on the study. If eligible, participants will be sent the online drink selection task via a URL (through Qualtrics). The selection task includes 64 drink options including: beer, cider, wine, alcohol-free beer, alcohol-free cider, alcohol-free wine and soft drinks. Depending on the allocated condition the proportions of the alcoholic and non-alcoholic drinks will vary (i. 75% non-alcoholic, 25% alcoholic ii. 50% non-alcoholic, 50% alcoholic iii. 25% non-alcoholic, 75% alcoholic). Participants select all the drinks for adults in their household that they would like to purchase in their next online Tesco shop. Once the selection task is complete, participants add the selected items to their Tesco basket and send details of their next delivery slot to the research team. On the delivery day, participants send their itemised proof of purchase to researchers.

What are the possible benefits and risks of participating?
Participants will be paid standard market research panel rates for participating in this study. There are no known risks of participating in the study.

Where is the study run from?
School of Psychological Sciences, University of Bristol (UK) and the Behaviour and Health Research Unit, University of Cambridge (UK)

When is the study starting and how long is it expected to run for?
November 2020 to September 2021

Who is funding the study?
Wellcome Trust (UK)

Who is the main contact?
Dr Natasha Clarke
n.clarke@bathspa.ac.uk

Study website

http://www.behaviourchangebydesign.iph.cam.ac.uk/

Type

Scientific

Contact name

Dr Natasha Clarke

ORCID ID

http://orcid.org/0000-0003-2375-4510

Contact details

Behaviour and Health Research Unit
University of Cambridge
Cambridge
CB2 0SR
United Kingdom
+44 (0)1223 762565
n.clarke@bathspa.ac.uk

Type

Public

Contact name

Miss Elkie Wootton

ORCID ID

Contact details

Behaviour and Health Research Unit
University of Cambridge
Cambridge
CB2 0SR
United Kingdom
+44 (0)1223 762565
bcbd.project.manager@medschl.cam.ac.uk

EudraCT/CTIS number

Nil known

IRAS number

ClinicalTrials.gov number

Nil known

Secondary identifying numbers

210223 Alcohol_purchasing_availability_protocol_v1.2

Scientific title

Impact of altering the relative availability of non-alcoholic vs alcoholic drinks on selection and purchasing: an online experimental study

Acronym

Study hypothesis

Altering the relative availability of a subset of drink options by increasing the proportion of non-alcoholic drinks (alcohol-free beer, cider and wine and soft drinks) and decreasing the proportion of alcoholic drinks (beer, cider and wine) will reduce the number of alcohol units selected.

Ethics approval(s)

Approved 19/01/2021, School of Psychological Science Research Ethics Committee at the University of Bristol (1 Cathedral Square, Bristol, Avon, BS1 5DD, UK; +44 (0)117 42 83065; research-governance@bristol.ac.uk), ref: 116124

Study design

Randomized controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Study setting(s)

Internet/virtual

Study type

Prevention

Patient information sheet

See additional files

Condition

Excess alcohol consumption

Intervention

Participants will be randomly assigned to one of three conditions in an experiment with a between-subjects factor of drink subset availability (i. 75% non-alcoholic, 25% alcoholic ii. 50% non-alcoholic, 50% alcoholic iii. 25% non-alcoholic, 75% alcoholic), in which the relative proportion (%) of alcohol-free beer, cider and wine and soft drinks will vary, compared to alcoholic beer, cider and wine options.

Selection
Participants will be randomised to one of three drink subset availability conditions within the online Qualtrics platform. Participants will view: i. a range of beers, ciders and soft drinks, and ii. a range of wines and soft drinks. These two drink ranges will each show 32 drink options. The order in which the two drink ranges (beer, cider and soft drinks first or wine and soft drinks first) are presented will be randomised. In each range, the drink options within the three sub-categories (i.e., i. beer and cider, alcohol-free beer and alcohol-free cider, or soft drinks, ii. wine, alcohol-free wine, or soft drinks) will be presented together under their respective headings but their order of presentation will be randomised. The relative availability (proportion) of non-alcoholic (alcohol-free beer, cider or wine alternatives and soft drinks) and alcoholic (beer, cider or wine) drink options – and therefore alcohol units – will vary according to the three conditions. Alcohol-free beer, cider and wine will be clearly labelled to ensure that they are not confused with alcoholic drinks. Each drink option presented will be a different brand, i.e., as the relative availability of non-alcoholic drink options increases, there will be a larger choice of brands from which to choose. Drink images will all be shown as bottles or cans, either as single items or multipacks, depending on the availability of products at Tesco.

Participants will be able to select as many drinks as they would like to purchase in their household grocery shop at Tesco. Then participants will be asked to provide their email address and answer questions regarding their demographics and typical drinking behaviour, and to briefly explain their drink choices.

Purchasing
After completing the selection task, participants will be automatically sent an email detailing their selected drinks. When participants complete the selection task, they will be prompted to check their email and provided with instructions to complete the purchasing stage of the study, alongside a link to the Tesco website. Participants will be sent an email on the day of their delivery or collection with a request to send proof of purchase (i.e., a copy of their itemised receipt) to the research team within 48 hours.

Intervention type

Behavioural

Primary outcome measure

Number of alcohol units selected (with an intention to purchase). Participants will be aware that they will be required to purchase the drink items chosen in the selection task and send proof of this to the research team. Therefore, the primary outcome of selection will be made in the context of intention to purchase and provide evidence of this behaviour. This is measured immediately, i.e. whilst participants are exposed to the availability intervention, and calculated from the selection task data

Secondary outcome measures

1. Number of alcoholic drinks selected, measured immediately, i.e. whilst participants are exposed to the availability intervention, and calculated from the selection task data
2. Number of non-alcoholic drinks selected, measured immediately, i.e. whilst participants are exposed to the availability intervention, and calculated from the selection task data
3. Total number of drinks selected, measured immediately, i.e. whilst participants are exposed to the availability intervention, and calculated from the selection task data
4. Proportion of total drinks selected that are alcoholic, measured immediately, i.e. whilst participants are exposed to the availability intervention, and calculated by dividing the number of alcoholic drinks selected by the total number of drinks
5. Number of alcohol units purchased, measured immediately after the selection task and calculated from the purchasing data (i.e. from proof of purchase)
6. Number of alcoholic drinks purchased, measured immediately after the selection task and calculated from the purchasing data (i.e. from proof of purchase)
7. Number of non-alcoholic drinks purchased, measured immediately after the selection task and calculated from the purchasing data (i.e. from proof of purchase)
8. Total number of drinks purchased, measured immediately after the selection task and calculated from the purchasing data (i.e. from proof of purchase)
9. Proportion of total drinks purchased that are alcoholic, measured immediately after the selection task and calculated by dividing the number of alcoholic drinks purchased by the total number of drinks

Overall study start date

01/11/2020

Overall study end date

01/09/2021

Reason abandoned (if study stopped)

Participant inclusion criteria

1. Aged 18 years or over;
2. Current Tesco online customer
3. Regularly consume alcohol – beer, cider and/or wine (i.e., at least once a week)
4. Regularly purchase alcohol – beer, cider and/or wine – online at Tesco (i.e., at least once a month, minimum £20 monthly spend on these drinks)
5. Willing to select drinks from 64 options, shown in an online task, to purchase in next online shop at Tesco
(Note: Options will include different brands of beer, cider, wine, alcohol-free beer, alcohol-free cider, alcohol-free wine and soft drinks available at Tesco; no additional drinks from these categories should be added to the Tesco shop)
6. Willing to complete online shop at Tesco, book a delivery (or Click and Collect) slot, and send the details to the research team within 48 hours of the drink selection task
7. Willing to send proof of purchase (i.e., itemised receipt) to the research team within 48 hours of delivery or collection date
8. Have a Tesco delivery or collection address in England or Wales

Participant type(s)

Healthy volunteer

Age group

Adult

Lower age limit

18 Years

Sex

Both

Target number of participants

600

Total final enrolment

737

Participant exclusion criteria

Does not meet the inclusion criteria

Recruitment start date

04/03/2021

Recruitment end date

01/08/2021

Countries of recruitment

England, United Kingdom

Study participating centre

Roots Research
50 Grand Parade
Brighton
BN2 9QA
United Kingdom

Organisation

University of Bristol

Sponsor details

12a Priory Rd
Bristol
BS8 1TU
England
United Kingdom
+44 (0)117 42 83065
research-governance@bristol.ac.uk

Sponsor type

University/education

Website

http://www.bristol.ac.uk/red/research-governance/

ROR

https://ror.org/0524sp257

Funder type

Research organisation

Funder name

Wellcome Trust

Alternative name(s)

Wellcome, WT

Funding Body Type

private sector organisation

Funding Body Subtype

Trusts, charities, foundations (both public and private)

Location

United Kingdom

Publication and dissemination plan

1. The protocol and the detailed statistical analysis plan will be pre-registered on the Open Science Framework: https://osf.io/x726n/
2. Planned submission of the main results of this study for publication in a peer-reviewed journal
3. Dissemination of the results to the public, policymakers and other researchers through targeted social media

Intention to publish date

31/03/2022

Individual participant data (IPD) Intention to share

No

IPD sharing plan

Anonymised participant-level data will be uploaded to the University of Bristol's data repository (https://data.bris.ac.uk/data/) and on the Open Science Framework project page (https://osf.io/x726n/). This data will be open access. This will uploaded upon publication of the study. Participants are informed of this before providing consent (see participant information sheet) – “At the end of the study your data would become “open data”. This means that it would be stored in an online database so that it is publicly available.” All aspects of the General Data Protection Regulation, Data Protection Act 2018 and the Freedom of Information Act 2000 will be adhered to. All personal data will be treated as confidential.

IPD sharing plan summary

Stored in repository

Study outputs