The online supermarket study
| ISRCTN | ISRCTN13729526 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN13729526 |
| Protocol serial number | v1.0 |
| Sponsor | University of Oxford |
| Funder | National Institute for Health Research |
- Submission date
- 26/02/2018
- Registration date
- 23/03/2018
- Last edited
- 10/08/2022
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Poor diet is a risk factor for heart disease. Saturated fat (SFA) in food increases the type of cholesterol (LDL-cholesterol) that increases the chances of heart disease. Cutting down on food containing SFA, e.g. swapping butter for plant-based spreads, could help lower the risk of heart disease. Researchers are currently investigating new ways of reducing SFA in the population's diet. This study is an online shopping experiment to find out which are the best food swaps which achieve the greatest impact on SFA, and also the swaps which are most acceptable to people. The researchers are also interested in whether they can change purchases by changing the way foods choices are presented online.
Who can participate?
Healthy volunteers aged 18 and over
What does the study involve?
Participants do a 'pretend' shop in an online supermarket specially designed to conduct this kind of experiment. They are randomly allocated to one of for groups. One group is offered lower SFA swaps to the products they first select. In a second group the position of foods in the list which appears on screen is changed so that lower SFA options are positioned higher up. In the third group both of these interventions are applied together. The fourth group see the default version of the website with no swaps offered and a random order of the foods displayed in response to each search. The amount of SFA in the final basket is calculated for the four groups.
What are the possible benefits and risks of participating?
If successful, these strategies can be delivered at scale supporting current efforts to help people make lifestyle changes to lower their risk of chronic diseases. There are no direct benefits or risks involved in participating in this study, but the participants are reimbursed for their effort.
Where is the study run from?
University of Oxford (UK)
When is the study starting and how long is it expected to run for?
February 2018 to February 2019
Who is funding the study?
National Institute for Health Research (NIHR) (UK)
Who is the main contact?
Dr Dimitrios Koutoukidis
dimitrios.koutoukidis@phc.ox.ac.uk
Contact information
Scientific
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
United Kingdom
 ORCID ID |
0000-0002-1955-7234 |
|---|---|
| Phone | +44 (0)1865617767 |
| dimitrios.koutoukidis@phc.ox.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomised controlled trial with a 2x2 factorial design |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | The effectiveness of individual-level and environmental-level interventions on food choices: an experimental online supermarket study |
| Study acronym | OLS |
| Study objectives | To investigate the magnitude of saturated fat change achieved in the shopping basket in response to an individual-level intervention and an environmental-level intervention, separately and in combination, compared to control (no intervention). |
| Ethics approval(s) | University of Oxford, Medical Sciences Interdivisional Research Ethics Committee, 08/02/2018, ref: R55722/RE001 |
| Health condition(s) or problem(s) studied | Food choices |
| Intervention | This study uses a bespoke virtual online supermarket shopping (OLS) platform, hosted by The University of Oxford, which emulates a real online supermarket for research purposes relating to food purchasing interventions. Participants will be randomly allocated to one of the following groups when shopping online: 1. Individual-level intervention: offering a swap to a product with less saturated fat (SFA) Swaps will be offered at point of selection i.e. when a participant selects an item to put in their shopping basket, if an alternative product exists that is lower in SFA within the same food category, the participant will be offered the chance to swap the item. Products offered as swaps will be within the same general price and weight range as the original item. 2. Environmental-level intervention: prominent positioning of lower SFA options This will apply to each list of foods offered to participants when searching for products. 3. A combination of individual- and environmental-level interventions This group will receive both interventions as described above. 4. Control Participants in this group will see the default version of the website with no swaps offered and a random order of the foods displayed in response to each search. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
Current primary outcome measure as of 20/07/2018: |
| Key secondary outcome measure(s) |
Current secondary outcome measures as of 20/07/2018: |
| Completion date | 07/02/2019 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | All |
| Target sample size at registration | 1240 |
| Total final enrolment | 1240 |
| Key inclusion criteria | 1. UK adults, aged ≥18 years 2. Able to speak and read English 3. Willing and able to give informed consent for participation in the study 4. Being the main (or shared) grocery shopper for their household 5. Having access to a computer and Internet |
| Key exclusion criteria | Having any dietary restriction |
| Date of first enrolment | 26/03/2018 |
| Date of final enrolment | 29/06/2018 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Woodstock Road
Oxford
OX2 6GG
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| IPD sharing plan | The current data sharing plans for the study are unknown and will be made available at a later date. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 07/06/2019 | 14/06/2019 | Yes | No |
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
| Protocol file | version 3.0 | 13/07/2018 | 10/08/2022 | No | No |
| Statistical Analysis Plan | version v1.0 | 13/07/2018 | 20/07/2018 | No | No |
Additional files
- ISRCTN13729526_SAP_v1.0_13Jul18.pdf
- Uploaded 20/07/2018
- ISRCTN13729526 Protocol and SAP v3.0 13Jul2018.pdf
- Protocol file
Editorial Notes
10/08/2022: Uploaded protocol (not peer-reviewed) as an additional file.
14/06/2019: Publication reference and total final enrolment number added.
20/07/2018: The following changes were made to the trial record:
1. The recruitment end date was changed from 12/06/2018 to 29/06/2018.
2. The primary and secondary outcome measures were updated.
3. Uploaded statistical analysis plan.
16/04/2018: The target number of participants was changed from 500 to 1240.
