Nudging customers towards healthier food and beverage purchases in an online supermarket
| ISRCTN | ISRCTN10491616 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN10491616 |
| Secondary identifying numbers | 2020.536 |
- Submission date
- 21/05/2021
- Registration date
- 26/05/2021
- Last edited
- 24/01/2022
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Unhealthy dietary patterns contribute to the development of obesity and cardiometabolic diseases such as heart disease and diabetes. Dietary patterns are, in turn, driven by several factors that range beyond individual choices. One of these factors concerns the food environment, in which supermarkets serve as key providers of foods and beverages. They therefore provide the opportunity to promote healthy dietary patterns among the population, not only through what is on offer but also how these products are presented and advertised. Health-promoting supermarket environments could be created using healthy food nudging. Healthy food nudges actively promote healthy product choices among customers without removing the unhealthy options. The aim of this study is to evaluate the effectiveness of single and combined nudging strategies in an online supermarket on the total percentage of healthy purchases, and whether the nudging strategies had different effects across food groups, and if there were differences in revenue following the nudging strategies.
Who can participate?
All customers of the participating online supermarket chain.
What does the study involve?
Customers visiting the online supermarket are randomly allocated to:
1. No intervention (regular online supermarket)
2. Addition of information nudges (symbols on healthy products)
3. Addition of availability nudges (unhealthy-to-healthy product swaps and healthy check-out suggestions)
4. Addition of information and availability nudges combined
For the 5-week study period sales data are collected from all customers placing a delivery order in the online supermarket.
What are the possible benefits and risks of participating?
The study does not involve direct benefits or risks for the participants.
Where is the study run from?
Amsterdam UMC, VU University (Netherlands)
When is the study starting and how long is it expected to run for?
June 2020 to October 2020
Who is funding the study?
1. Dutch Heart Foundation (Netherlands)
2. Netherlands Organization for Health Research and Development (Netherlands)
Who is the main contact?
Josine Stuber
j.stuber@amsterdamumc.nl
Contact information
Scientific
De Boelelaan 1117
Amsterdam
1081HV
Netherlands
 ORCID ID |
0000-0001-7825-018X |
|---|---|
| Phone | +31 (0)204445830 |
| j.stuber@amsterdamumc.nl |
Public
De Boelelaan 1089a
Amsterdam
1081 HV
Netherlands
| ORCID ID |
0000-0001-7825-018X |
|---|---|
| Phone | +31 (0)204445830 |
| j.stuber@amsterdamumc.nl |
Study information
| Study design | Multi-arm parallel-group individually randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised parallel trial |
| Study setting(s) | Internet/virtual |
| Study type | Prevention |
| Participant information sheet | No participant information sheet available |
| Scientific title | Nudging customers towards healthier food and beverage purchases in a real-life online supermarket: a multi-arm randomized controlled trial |
| Study objectives | Implementation of nudging strategies in an online supermarket result in an overall higher percentage of healthy products purchased, and online nudging strategies have differential effects across food groups. Moreover, online nudging strategies do not result in differences in total retailer revenue. |
| Ethics approval(s) | Approved 29/09/2020, the medical ethics review board of VU University Medical Center Amsterdam (Medisch Ethische Toetsingscommissie VUmc, De Boelelaan 1109, kamer 08A-08, Postbus 7057, 1081 HV Amsterdam; +31 (0)20 444 5585; metc@vumc.nl) reviewed the study protocol and deemed the Medical Research Involving Human Subjects Act (WMO) as not applicable, ref: 2020.536 |
| Health condition(s) or problem(s) studied | Promoting healthier food and beverage purchases among the general population |
| Intervention | Randomization is concealed as supermarket employees conduct the randomization and allocation of customers to one of the trial arms in a software system name Blueconic (Blueconic. Customer data platform. Boston, USA. 2020). The system is set to randomize and allocate the customers in equal distribution percentages of 25% across all four trial arms. Two types of online nudges on healthy products are used, consisting of information nudges and availability nudges. The information nudge highlighted specific product information of healthy products via the use of labels highlighting a product’s tastiness, convenience, or popularity. The availability nudge increases the number of placements of healthy products, via unhealthy-to-healthy product swaps and healthy check-out suggestions. Customers visiting the online supermarket are randomly assigned to: Arm 1: no intervention (regular online supermarket) Arm 2: addition of information nudges (symbols on healthy products) Arm 3: addition of availability nudges (unhealthy-to-healthy product swaps and healthy check-out suggestions) Arm 4: addition of information and availability nudges combined The trial was implemented in the online supermarket of a Dutch supermarket chain for five consecutive weeks between mid-August until mid-September 2020. During this period, sales data were collected from all customers placing a delivery order in the online supermarket. |
| Intervention type | Behavioural |
| Primary outcome measure | The total percentage of healthy purchases per individual shop measured using customer sales data based on the total weight of products purchased during the 5-week study period. |
| Secondary outcome measures | Secondary outcome measure: Total percentage of healthy purchases within 19 food groups per individual shop measured using customer sales data based on the total weight of products purchased during the 5-week study period Tertiary outcome measure: Total retailer revenue measured using customer sales data based on the total amount of Euros spent during the 5-week study period |
| Overall study start date | 01/06/2020 |
| Completion date | 01/10/2020 |
Eligibility
| Participant type(s) | All |
|---|---|
| Age group | Adult |
| Sex | Both |
| Target number of participants | 22000 individual shops are anticipated during the trial period based on historical sales data of the supermarket chain. |
| Total final enrolment | 15045 |
| Key inclusion criteria | All customers placing a delivery order (i.e., shops) in a real-life online supermarket between mid-August until mid-September 2020 |
| Key exclusion criteria | Shops reflecting an average household grocery shopping pattern are included in the analysis. Therefore, all business-related customers, and customers who purchased >90% of products in their shop from alcohol, other foods, and snacks, are excluded from the analysis. |
| Date of first enrolment | 15/08/2020 |
| Date of final enrolment | 15/09/2020 |
Locations
Countries of recruitment
- Netherlands
Study participating centre
Amsterdam
1081 HV
Netherlands
Sponsor information
Hospital/treatment centre
De Boelelaan 1089a
Amsterdam
1081 HV
Netherlands
| Phone | +31 (0)204445830 |
|---|---|
| j.stuber@amsterdamumc.nl | |
| Website | https://www.vumc.nl/ |
"ROR" |
https://ror.org/00q6h8f30 |
Funders
Funder type
Charity
Private sector organisation / Trusts, charities, foundations (both public and private)
- Alternative name(s)
- Heart Foundation
- Location
- Netherlands
Private sector organisation / Other non-profit organizations
- Alternative name(s)
- Netherlands Organisation for Health Research and Development
- Location
- Netherlands
Results and Publications
| Intention to publish date | 01/03/2022 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Not expected to be made available |
| Publication and dissemination plan | Planned publication in a high-impact, preferably open access, peer-reviewed journal. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study are not expected to be made available due to confidentiality agreements with the collaboration supermarket chain. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Statistical Analysis Plan | 01/06/2021 | No | No | ||
| Results article | 17/01/2022 | 24/01/2022 | Yes | No |
Additional files
- ISRCTN10491616_SAP.pdf
- Uploaded 01/06/2021
Editorial Notes
24/01/2022: Publication reference added.
11/10/2021: The intention to publish date was changed from 01/10/2021 to 01/03/2022.
01/06/2021: The statistical analysis plan has been uploaded as an additional file.
25/05/2021: Trial's existence confirmed by the Medical Ethics Review Committee of VU University Medical Center.
