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Diet QualityDINENCT05070442

Diet Improvement Through Normative Experimentation

A study testing Norm-based messaging and peer comparison features and Financial Incentives leveraging on loss aversion in people with Diet Quality, run by Duke-NUS Graduate Medical School at 1 site in Singapore.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study aims to use a three-arm randomized control trial (RCT) implemented in a fully functional experimental online grocery store, to explore the effects of two low-cost information and incentive-based strategies. Read more about this study

Who is it for?
Ages 21 years and olderHealthy volunteers can take part
Conditions the study is for
Diet Quality
What is being tested?
Norm-based messaging and peer comparison features and Financial Incentives leveraging on loss aversion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
248 participants
Where
1 siteSingapore
Study dates
22 Apr 2022to 26 Oct 2022
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 21 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Singapore resident
  • Age 21 and above
  • Must be the primary weekly grocery shopper in their household

Who cannot join

  • Non-Singapore resident
  • Non-primary grocery shopper in their household
  • Less than 21 years old

Trial locations and contacts

1 site in 1 country.

Singapore1 site
  • Duke-NUS Graduate Medical School

    Singapore, 169857

Other trials in Singapore

About this study

This study aims to use a three-arm randomized control trial (RCT) implemented in a fully functional experimental online grocery store, to explore the effects of two low-cost information and incentive-based strategies. These strategies comprise of injunctive norm-based messaging and the use of financial incentive leveraging on loss aversion to encourage the purchase of healthy foods. The investigators have set up a store wherein products may be purchased by participants and subsequently delivered to homes in some of the conditions. This increases the external validity of these interventions and enables investigators to establish greater confidence in their generalizability.

Read the detailed description

The Asia-Pacific is faced with an epidemic of rising rates of chronic disease. Poor diet quality is a demonstrated risk factor for non-communicable diseases. Excess intake of calories, saturated fat and sodium increases the risk of obesity, heart disease, diabetes, and other chronic conditions.

Behavioral economics has emerged as a promising strategy to increase the effectiveness of interventions aimed to address risk factors for non-communicable diseases (NCDs). Yet, there is a gap in knowledge concerning how norm-based messaging and peer influence interventions can be implemented to improve diet quality.

Using a three-arm randomized trial with a 3x3 crossover design, investigators aim to determine whether norm-based messaging and peer comparisons, with or without financial incentives, improve diet quality.

Each participant will be exposed to all of the following intervention arms in random order:

Arm 1: Control arm. Participants will experience an unmodified version of NUSMart which replicates the traditional shopping experience of online grocery stores.

Arm 2: Participants will experience a modified version of NUSMart with norm-based messaging and peer comparison features enabled. Nutri-Score labels will be enabled and displayed on all products within the store. A floating side panel will provide a visual indicator of the participants' average weighted Nutri-Score.

Arm 3: Same as Arm 2, except participants are notified of an additional $5 reward towards participation reimbursement. However, this additional $5 will be forfeited if the basket average weighted Nutri-Score falls below the average of participants' peers'. (Financial incentive leveraging on loss aversion).

Investigators hypothesize the following:

Primary hypothesis: Diet quality, as measured by mean Nutri-Score weighted by number of servings of all basket items, will be greatest when exposed to the intervention with norm-based messaging with incentive (Arm 3), followed by the intervention with norm-based messaging without the incentive (Arm 2), followed by Control (Arm 1).

Investigators will test this hypothesis in total, and separately for foods and beverages given Singapore's focus on reducing intake of sugar-sweetened beverages.

Conditions
Diet Quality
Being tested
Norm-based messaging and peer comparison features, Financial Incentives leveraging on loss aversion
Keywords
Nutri-Score labels, Social norms, Peer comparison, Financial incentives, Loss aversion, Online grocery shopping

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Norm-based messaging and peer comparison featuresBehavioural

    Participants are shown a version of NUSMart which includes Nutri-Score labels that are enabled and displayed besides all the products in the store. Additionally, they are shown a video that gives them background information about Nutri-Score labels and describes the following features enabled in this intervention:

    • Norm-based messaging will be displayed in the form of a happy or sad emoticon based on whether the participant's current basket average Nutri-Score (weighted by number of servings) is above or below "other shoppers" (Nutri-Score=3.98).
    • Peer comparison will be implemented as a vertical ruler display of the participant's current basket average Nutri-Score (weighted by number of servings) as well as that of their "peers".

    Nutri-Score=3.98 was chosen as it is 10% better than the mean Nutri-Score of baskets purchased by participants in the Nutri-Score labelled intervention arm of a prior study.

  • Financial Incentives leveraging on loss aversionBehavioural

    Participants are informed that they have received an additional $5 towards their participant reimbursement. However, this amount will be forfeited if they check-out with a basket average Nutri-Score (weighted by the number of servings) that falls below the average Nutri-Score of "other shoppers" i.e. 3.98. An indicator on the screen that informs the participants of this potential forfeiting will be included.

Study groups in NCT05070442
Study groupRoleWhat they receive
Control Arm (Arm 1)No interventionParticipants will experience an unmodified version of NUSMart which replicates the traditional shopping experience of online grocery stores.
Norms Arm (Arm 2)ExperimentalParticipants will experience a modified version of NUSMart with norm-based messaging and peer comparison features enabled. Nutri-Score labels will be enabled and displayed on all products within the store. A floating side panel will provide a visual indicator of the participants' average weighted Nutri-Score.
Receives: Behavioral: Norm-based messaging and peer comparison features
Norms and Incentive Arm (Arm 3)ExperimentalSame as Arm 2, except participants are notified that they have been awarded an additional $5 towards their participation reimbursement. However, this additional $5 will be forfeited if their basket average weighted Nutri-Score falls below the average of their peers'. (Financial incentive leveraging on loss aversion).
Receives: Behavioral: Norm-based messaging and peer comparison features; Behavioral: Financial Incentives leveraging on loss aversion

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Diet Quality

    Diet quality, as measured by raw Nutri-Score points (-15 to 40) weighted by number of servings of all basket items. Here, a smaller value means a better outcome. Raw Nutri-Score is measured according to the guidelines from the Sante Publique France.

    Measured: After completion of data collection, an average of about 5 months

Secondary outcomes (6)
  1. Average Nutri-Score

    Average Nutri-Score (1 to 5) weighted by number of servings of all basket items. Here, a higher value means a better outcome. This is calculated by converting Nutri-Score letters to numbers such that Nutri-Score E is 1, D is 2 and so on till Nutri-Score A which is 5.

    Measured: After completion of data collection, an average of about 5 months

  2. Average Calories

    Average calories per shopping trip.

    Measured: After completion of data collection, an average of about 5 months

  3. Average Sodium

    Average sodium per shopping trip.

    Measured: After completion of data collection, an average of about 5 months

  4. Average Sugar

    Average sugar per shopping trip.

    Measured: After completion of data collection, an average of about 5 months

  5. Average Fat

    Average fat per shopping trip.

    Measured: After completion of data collection, an average of about 5 months

  6. Average Saturated Fat

    Average saturated fat per shopping trip.

    Measured: After completion of data collection, an average of about 5 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted7 Oct 2021
  2. Study start22 Apr 2022
  3. Primary completion26 Oct 2022
  4. Study completion26 Oct 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Health services research
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
248 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05070442
Sponsor's protocol ID
NIHA-2018-002 (Study 2)
Acronym
DINE
Status last verified
Feb 2023
First submitted
20 Sep 2021
Last updated
15 Feb 2023
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Norm-based messaging and peer comparison features and Financial Incentives leveraging on loss aversion in people with Diet Quality, run by Duke-NUS Graduate Medical School at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Feb 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Diet Quality (time frame: After completion of data collection, an average of about 5 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Feb 2023.

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