Does the size of wine glasses impact on restaurant wine sales?
| ISRCTN | ISRCTN17958895 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN17958895 |
| Secondary identifying numbers | N/A |
- Submission date
- 21/07/2017
- Registration date
- 25/07/2017
- Last edited
- 07/01/2020
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Alcohol consumption is a major cause of disease. Sometimes drinkers are unaware of how much they are being served and how much they consume. Previous research has suggested that the size of wine glasses might affect purchasing of wine, with larger glasses leading to more purchases. The aim of the current study is to try to replicate this previous work and establish the reliability of any effect of glass size on purchasing.
Who can participate?
One independent restaurant in Cambridge UK is participating in the study. Data will be based on customers visiting the restaurant during the 18-week study period.
What does the study involve?
The restaurant provides different glass sizes to customers who order wine based off a schedule. First, they introduce medium-size wine glasses (29cl glasses) in the restaurant for a period of two weeks. The portion sizes of wine sold is not changed (the restaurant continues to sell wine by the glass (125ml and 175ml portions) and by the bottle. All portion sizes are served in the same wine glass. We then change to a larger (35cl) wine glass for the next two weeks. The medium-size wine glass is then used again for two weeks. For weeks seven to eight smaller (23cl) glasses are used. Then this pattern is repeated again (i.e. medium-size, larger, medium-size, smaller), and then the study finishes with a final two week period where the medium-size glasses are used again. The sales of wine when using the medium-size glasses to sales when using each of the larger and smaller glass sizes are compared.
What are the possible benefits and risks of participating?
There are no benefits or risks with participating.
Where is the study run from?
Testing will take place in one independent restaurant in Cambridge (UK). The study is run from the Behaviour and Health Research Unit at the University of Cambridge (UK).
When is the study starting and how long is it expected to run for?
April 2017 to December 2017
Who is funding the study?
Department of Health Policy Research Programme (Policy Research Unit in Behavior and Health) (UK)
Who is the main contact?
Dr Rachel Pechey
Contact information
Scientific
Behaviour and Health Research Unit
Institute of Public Health
University of Cambridge
Cambridge
CB2 0SR
United Kingdom
 ORCID ID |
0000-0002-6558-388X |
|---|
Study information
| Study design | Multiple treatment reversal design, whereby one restaurant changes the size of glasses used with wine purchases every fortnight for an 18-week period |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Multiple treatment reversal design |
| Study setting(s) | Other |
| Study type | Prevention |
| Participant information sheet | ISRCTN17958895_PIS_24Jul17.pdf |
| Scientific title | The impact of wine glass size on wine sales: a replication study in a restaurant setting |
| Study objectives | Changing the size of wine glasses will alter wine sales in the restaurant, with larger wine glasses increasing sales. |
| Ethics approval(s) | University of Cambridge Research Ethics Committee, 09/05/2017, ref: Pre.2017.035 |
| Health condition(s) or problem(s) studied | Alcohol consumption |
| Intervention | The restaurant is the participant in this study. Customers at the restaurant are unaware of the intervention. When they order wine, they receive the portion ordered as usual, but this portion is served in a wine glass that is smaller, medium-size or larger, depending on the week of the study. The restaurant's usual glasses are replaced with different-sized glasses (of the same glass design). Glasses will have smaller (23cl), medium (29cl) or larger (35cl) capacity. Glasses will be changed fortnightly, over an 18-week period, as per the following schedule: A: Medium-sized (290ml) glass B: Larger (350ml) glass A: Medium-sized (290ml) glass C: Smaller (230ml) glass A: Medium-sized (290ml) glass B: Larger (350ml) glass A: Medium-sized (290ml) glass C: Smaller (230ml) glass A: Medium-sized (290ml) glass There will be no follow up with customers (The change in glasses is not expected to raise any issues for customers. As well as potentially causing issues for the study design, obtaining consent (and debriefing) would interfere with the procedures for serving customers in participating venues.) |
| Intervention type | Behavioural |
| Primary outcome measure | The daily volume (ml) of wine purchased throughout the 18 weeks of the study, obtained from the till records of the restaurant |
| Secondary outcome measures | There are no secondary outcome measures. |
| Overall study start date | 01/04/2017 |
| Completion date | 31/12/2017 |
Eligibility
| Participant type(s) | Other |
|---|---|
| Age group | Other |
| Sex | Both |
| Target number of participants | One independent restaurant |
| Key inclusion criteria | UK restaurants serving wine |
| Key exclusion criteria | There are no exclusion criteria |
| Date of first enrolment | 07/07/2017 |
| Date of final enrolment | 01/08/2017 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
University of Cambridge
Cambridge
CB2 0SR
United Kingdom
Sponsor information
University/education
Cambridge Research Office
16 Mill Lane
Cambridge
CB2 1SB
England
United Kingdom
"ROR" |
https://ror.org/013meh722 |
|---|
Funders
Funder type
Government
No information available
Results and Publications
| Intention to publish date | 01/04/2019 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Not expected to be made available |
| Publication and dissemination plan | This study has been pre-registered on the Open Science Framework (https://osf.io/sekmt/), further information is available there. Intention to write up the study for publication in early 2018. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study is not expected to be made available as the datatset will comprise sales data from one restaurant, which is commercially sensitive. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | 24/07/2017 | 10/08/2017 | No | Yes | |
| Results article | results | 17/07/2019 | 19/07/2019 | Yes | No |
Additional files
- ISRCTN17958895_PIS_24Jul17.pdf
- Uploaded 10/08/2017
Editorial Notes
19/07/2019: Publication reference added.
26/10/2018: The intention to publish date has been changed from 01/04/2018 to 01/04/2019
05/01/2018: Internal review.
10/08/2017: Participant information sheet has been added.
