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Trial registered on ANZCTR


Registration number
ACTRN12617000015347
Ethics application status
Approved
Date submitted
20/12/2016
Date registered
5/01/2017
Date last updated
5/01/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Consumer Choice of Pre-Packaged Foods that Vary by Nutrition Information and Price
Scientific title
Consumer Choice of Pre-Packaged Foods that Vary by Nutrition Information and Price
Secondary ID [1] 290785 0
None
Universal Trial Number (UTN)
U1111-1191-0600
Trial acronym
Linked study record
ACTRN12616000626460

Health condition
Health condition(s) or problem(s) studied:
Obesity 301413 0
Coronary heart disease 301414 0
Hypertension 301415 0
Type 2 diabetes 301416 0
Condition category
Condition code
Public Health 301145 301145 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Respondents will be presented with 8 choice sets, each containing images of four hypothetical food packs, and will be asked to select which product they would like to purchase (or if they would not purchase any product from the choice set). Participants will be randomised to one of the three front-of-pack label conditions; the Daily Intake Guide, Multiple Traffic Lights or the Health Star Rating. The food pack images will either contain the specified front-of-pack label or no label. The food packs will also vary according to the following attributes: healthiness (3 levels), health claims (4 levels), price (3 levels) and food type (4 levels). Each food pack will contain one level of each attribute. All attributes and their levels are described in detail below.

Front-of-pack label:
4 levels: no label (control condition), Daily Intake Guide, Multiple Traffic Lights or the Health Star Rating. Each participant will only see one type of label (or no label) across all products.

Food type:
4 levels: corn flakes, cookies, pizza, yogurt. Each participant will be exposed to all 4 levels of this attribute (i.e. they will be presented with 2 packs of each food type).

Health claims:
4 levels: no claim (control condition) nutrient content claim, general level claim, higher level claim.

Price:
Contains 3 levels: cheap, moderate price, expensive.

Healthiness:
Contains 3 levels: unhealthy, moderately healthy, healthy.

Each choice set will be presented for 30 seconds. Participants will complete the experiment online via their own personal computer. Participants will have the option to complete the experiment in one session or log out and return to it at a later time.
Intervention code [1] 296697 0
Prevention
Comparator / control treatment
A repeated measures design will be used testing multiple interventions simultaneously within and across participants. Front-of-pack label, health claim, healthiness, price and food type will vary across foods to reveal to what extent these variables influence choice of and willingness to pay for foods. A control condition will be used for the attributes front-of-pack label and health claim. Comparisons will be conducted across the levels of the remaining attributes (food type, price, healthiness) to observe how choice varies across levels.
Control group
Active

Outcomes
Primary outcome [1] 300553 0
The aggregate utility provided by the different levels of each attribute, as measured by the presence/absence of different attribute levels on the food pack image that is selected within a choice set.
Timepoint [1] 300553 0
Within 30 seconds of exposure to the choice set
Secondary outcome [1] 330294 0
Whether a choice was made or not (i.e., due to timer running out or respondents opting out of the decision).
Timepoint [1] 330294 0
Within 30 seconds of exposure to the choice set

Eligibility
Key inclusion criteria
Participants must be aged over 10 and currently reside in Australia.
Minimum age
10 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Demographic quotas based on age, sex and location will be used. Participants will be excluded if the quota bracket which they belong in has been filled.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
The survey will be completed online via a desktop or laptop computer. Participants will be first assessed for eligibility to participate based on demographic quotas and eating habits. They will provide demographic information (age, gender, socioeconomic status) and state the frequency with which they buy and consume the foods used in the survey. Participants who fall within a demographic category that has reached its quota or stated that they “never” purchase or consume more than two of the four foods used in the survey will not progress further. Those who do progress will answer questions on diet, nutrition knowledge, food purchasing behaviors and attention to and preference for nutrition information on food packs before completing the choice task. They will then complete 8 choice sets containing 4 mock packs (of the same food type), presented in a row. Participants will be randomly assigned to 1 of 3 versions of the choice task. Within each version only one type of FoPL will be present or absent on packs. Participants will be simultaneously allocated to survey versions until quotas are reached.

Thirty blocks consisting of 2 choice sets each will be created in NGene using the following inputs: FoPL (2 levels: no FoPL, FoPL: DIG/MTL/HSR), health claim (4 levels: none, nutrient content, general level, higher level), healthiness (3 levels: unhealthy, moderately healthy, healthy) and price (3 levels: cheap, moderate, expensive). An efficient design allowing for estimation of main effects and 2 way interaction effects will be used resulting in a D error of 0.094. This design will be replicated 12 times across each of the 4 levels of food type the 3 levels of FoPLs. Within their allocated FoPL condition, each participant will view 1 block (2 choice sets) from each of the 4 food products. The order in which these choice sets are presented will be random.

The choice task will be designed to be as realistic as possible within the constraints of an online survey. To replicate the time pressures present in many food purchase decisions, participants will be given 30 seconds to make their selection. Much like a real world shopping context, the NIP will be available to participants who actively made the choice to view it. Participants will have the option to view the NIP (one at a time) for any of the 4 mock packs within a choice set by clicking a link below the mock pack image. They will also be able to zoom in on any part of the mock pack image. Finally, participants wil have the option to select none of the mock packs.
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 295204 0
Government body
Name [1] 295204 0
Australian Research Council
Address [1] 295204 0
Level 2, 11 Lancaster Place
Canberra Airport ACT 2609
Country [1] 295204 0
Australia
Primary sponsor type
University
Name
Curtin University
Address
Curtin University, Kent St,
Bentley,
WA, 6102
Country
Australia
Secondary sponsor category [1] 294037 0
None
Name [1] 294037 0
None
Address [1] 294037 0
Country [1] 294037 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296555 0
Curtin University Ethics Committee
Ethics committee address [1] 296555 0
Curtin Univeristy, Kent St,
Bentley,
WA, 6102
Ethics committee country [1] 296555 0
Australia
Date submitted for ethics approval [1] 296555 0
15/12/2014
Approval date [1] 296555 0
15/01/2015
Ethics approval number [1] 296555 0
RDHS-11-15

Summary
Brief summary
The non communicable diseases associated with poor diet (e.g., high blood pressure, high blood cholesterol, obesity and poor metabolic outcomes) are increasing in prevalence but are also preventable.

Nutrition labels on the front of food packs is one public health intervention designed to assist people to consume a healthy diet. A variety of other information (health related and otherwise) is available on food packs for consumers to incorporate into their purchase decisions. (such as the Nutrition Information Panel, health claims, price, etc). These sources of information often occur together on food packs, yet past research has generally look at the isolated effects of individual forms of nutrition information without consideration of how these pieces of information interact. The primary aim of this study is to investigate how nutrition information format, healthiness and price interact to affect consumer product choice.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 71278 0
Dr Zenobia Talati
Address 71278 0
School of Psychology and Speech Pathology,
Curtin University, Kent St,
Bentley,
WA, 6102
Country 71278 0
Australia
Phone 71278 0
+61 8 92664396
Fax 71278 0
Email 71278 0
zenobia.talati@curtin.edu.au
Contact person for public queries
Name 71279 0
Dr Zenobia Talati
Address 71279 0
School of Psychology and Speech Pathology,
Curtin University, Kent St,
Bentley,
WA, 6102
Country 71279 0
Australia
Phone 71279 0
+61 8 92664396
Fax 71279 0
Email 71279 0
zenobia.talati@curtin.edu.au
Contact person for scientific queries
Name 71280 0
Dr Zenobia Talati
Address 71280 0
School of Psychology and Speech Pathology,
Curtin University, Kent St,
Bentley,
WA, 6102
Country 71280 0
Australia
Phone 71280 0
+61 8 92664396
Fax 71280 0
Email 71280 0
zenobia.talati@curtin.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary