Plain English Summary
Background and study aims
There is has been little research on whether selling smaller portions of alcoholic drinks in pubs and bars reduces the total amount consumed. This study aims to investigate whether adding a two-third pint option for beer and cider sold on tap or removing the largest serving size for a glass of wine reduces the amount that is drunk.
Who can participate?
Licensed premises that offer beer and/or wine and are willing to change the serving sizes of beer and/or wine that they offer.
What does the study involve?
Licenced premises who agree to introduce a 2/3 pint serving size for all of the beer, cider and ale they available on tap will do so for a period of at least 4 weeks. Premises will also be asked to inform customers of the 2/3 pints option by putting signs up.
Licenced premises who agree to remove the 250-ml serving for glasses of wine will do so for a period of at least 4 weeks. Premises will be asked to remove mention of the 250-ml serving from menus and signs as necessary.
Sales data will be collected from bars for a period of at least 12 weeks, covering 4 weeks of business as usual, 4 weeks of the intervention and 4 weeks of going back to business as usual.
What are the possible benefits and risks of participating?
A possible benefit of participating is the opportunity to contribute to a better understanding of how the serving sizes of beer and wine affect sales. Student bars could also contribute to the NUS initiative ‘Alcohol Impact' for safe drinking in students. Licenced premises may benefit from publicity in taking part in this research once the results have been published, but can choose to stay anonymous if they wish. There is no change for the customers except the serving sizes, so there is no risk or benefit to visiting premises participating in the study.
Where is the study run from?
Institute of Public Health, University of Cambridge (UK)
When is the study starting and how long is it expected to run for?
April 2019 to July 2020
Who is funding the study?
The Wellcome Trust
Who is the main contact?
Professor Theresa Marteau, tm388@medschl.cam.ac.uk.
Trial website
Contact information
Type
Scientific
Primary contact
Prof Theresa Marteau
ORCID ID
http://orcid.org/0000-0003-3025-1129
Contact details
Institute of Public Health
University of Cambridge
Robinson Way
CB2 0SR.
Cambridge
CB2 0SR
United Kingdom
01223 762567
tm388@medschl.cam.ac.uk
Additional identifiers
EudraCT number
Nil known
ClinicalTrials.gov number
Nil known
Protocol/serial number
Nil known
Study information
Scientific title
Modifying the range of serving sizes in bars and restaurants to reduce sales of alcohol: a field study
Acronym
Study hypothesis
1. Introducing the option for two-thirds of a pint for beer and cider reduces the amount of beer and cider sold.
2. Removing the largest available serving of a glass of wine (250 ml or 175 ml) reduces the amount of wine sold.
Ethics approval
Approved 02/08/2019, Psychology Research Ethics Committee of the University of Cambridge (School of the Biological Sciences, 17 Mill Lane, Cambridge, CB2 1RX; +44 (0)1223 766876; cheryl.torbett@admin.cam.ac.uk), ref: PRE.2019.035
Study design
Cross-over study
Primary study design
Interventional
Secondary study design
Cross-over study
Trial setting
Community
Trial type
Prevention
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet.
Condition
Excessive alcohol consumption
Intervention
Intervention 1: Adding a two-thirds pint serving size
Sites will add a two-thirds pint serving size for all beers and ciders available on tap. The two-thirds pint will be offered in addition to the existing one pint and half-pint serving sizes, with proportionate pricing as far as is possible i.e. with a price which is linear-by-volume between the pint and half-pint sizes. Sites will choose two-thirds pint glasses to fit with their existing glassware, to be provided by the researchers. Bars will be allowed to keep the glassware after the study.
As part of the intervention, sites will adopt a range of strategies in keeping with their existing practices to draw customers’ attention to the new two-thirds pint option, including information on menus, signs behind the bar and prompting by bar staff when customers are ordering their drink. These practices will be described but not controlled.
Intervention 2: Removing the largest serving size for glasses of wine
Sites will reduce their range of serving sizes for glasses of wine by removing the largest serving size for a glass of wine in their existing range. This will either be 250 ml or 175 ml, with 125 ml sizes always available in keeping with current regulations for selling alcohol in licensed premises. Menus and signage will be updated to reflect this change.
The study has a multiple treatment reversal design with at least three consecutive 4-week periods as follows: ABA, where A represents the baseline periods during which standard serving sizes will be served and B represents the intervention periods in which the range of serving sizes will be modified. Willing sites will complete two additional 4-week periods (BA, resulting in ABABA).
Sites agreeing to implement both interventions will first complete the agreed number of reversals for intervention 1 followed by the agreed number of reversals for intervention 2 (or vice versa).
Intervention type
Behavioural
Phase
Drug names
Primary outcome measure
Intervention 1:
Daily volume (in ml) of beer and cider purchased (including on tap, bottle or can), measured using electronic records of sales
Intervention 2:
Daily volume (in ml) of wine sold (including by the glass, bottle and carafe), measured using electronic records of sales
Sales will be recorded for 12 weeks, including 4 weeks of business as usual before the intervention, 4 weeks of the intervention and 4 weeks going back to business as usual after the intervention.
Secondary outcome measures
1. Daily volume of beer and cider sold by serving size (pint, ½ pint, 2/3 pint, bottle sizes, can sizes) measured using electronic records of sales
2. Daily volume of wine purchased by serving size (125 ml, 175 ml, 250 ml, carafe, 750 ml bottle) measured using electronic records of sales
3. Daily volume of alcohol sold excluding beer and cider (during intervention 1) or wine (during intervention 2) measured using electronic records of sales
4. Daily revenue from food and alcoholic and non-alcoholic drink measured using electronic records of sales
5. Daily number of transactions measured using electronic records of sales
6. Daily amount of beer and cider (during intervention 1) or wine (during intervention 2) sold in units of alcohol (in cases where it is practical to extract this information from electronic sales data) measured using electronic records of sales
Sales will be recorded for 12 weeks, including 4 weeks of business as usual before the intervention, 4 weeks of the intervention and 4 weeks going back to business as usual after the intervention.
Overall trial start date
02/04/2019
Overall trial end date
31/07/2020
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Licensed premises that sell beer (and/or cider) on tap in sizes larger than two-thirds of a pint (for intervention 1)
2. Willing to introduce a two-thirds pint serving size for all beer and cider available on tap at a proportionate price (for intervention 1)
3. Sell wine by the glass in serving sizes greater than 125 ml (i.e. 175 ml or 250 ml) (for intervention 2)
4. Willing to cap the serving size of a glass of wine (for intervention 2)
5. Have an electronic point of sale (EPOS) till system to record daily sales of all drinks and their served sizes
Participant type
All
Age group
Adult
Gender
Both
Target number of participants
Customers of 23 licensed premises
Participant exclusion criteria
Does not meet inclusion criteria
Recruitment start date
27/08/2019
Recruitment end date
29/02/2020
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Institute of Public Health
University of Cambridge
Robinson Way
Cambridge
CB2 0SR
United Kingdom
Sponsor information
Organisation
University of Cambridge
Sponsor details
Cambridge Research Office
16 Mill Lane
Cambridge
CB2 1SB
Cambridge
CB2 1SB
United Kingdom
Cambridge
CB2 1SB
United Kingdom
01223 7766362
Jo.Dekkers@admin.cam.ac.uk
Sponsor type
University/education
Website
https://www.research-operations.admin.cam.ac.uk/about-us/contact-us
Funders
Funder type
Research organisation
Funder name
Wellcome Trust
Alternative name(s)
Funding Body Type
private sector organisation
Funding Body Subtype
International organizations
Location
United Kingdom
Results and Publications
Publication and dissemination plan
The findings from this study will be published in at least one scientific journal in 2020 and made available open access. They will also be presented at one or more scientific meetings. The data will be made available for sharing via the University of Cambridge Research Data Repository or Open Science Framework online data repository once the findings have been published.
IPD sharing statement:
The study will not use individual-level data: the unit of randomisation, data collection and analysis will be individual public houses and bars. The datasets generated and/or analysed during the current study will be stored in a publicly available repository. All study data will be anonymised using a unique numeric identifier. At the appropriate time, the anonymous study datasheet will be locked and deposited on the University of Cambridge Data Repository. If a publican decides that they do not want their data to be used after their participation they have the right to request that their data are withdrawn from the study. They can request this up to two weeks after study completion. Publicans are made aware of this prior to giving consent to their participation in the study and to the use of their anonymised study data.
Intention to publish date
31/12/2020
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list