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Trial registered on ANZCTR


Trial ID
ACTRN12614000206628
Ethics application status
Approved
Date submitted
12/02/2014
Date registered
26/02/2014
Date last updated
3/11/2015
Type of registration
Prospectively registered

Titles & IDs
Public title
SaltSwitch: A randomised controlled trial of the effect of a smartphone application to support lower salt food choices
Scientific title
Comparison of the SaltSwitch smartphone application versus control on the salt purchases of households where at least one member has diagnosed cardiovascular disease
Secondary ID [1] 284079 0
Nil known
Universal Trial Number (UTN)
U1111-1153-2468
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiovascular disease 291141 0
Condition category
Condition code
Cardiovascular 291483 291483 0 0
Hypertension
Diet and Nutrition 291531 291531 0 0
Other diet and nutrition disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The intervention group will receive the SaltSwitch smartphone application for 4-weeks. SaltSwitch enables users to scan the barcode of a packaged food and receive an immediate, interpretive traffic light nutrition label on the phones screen. Traffic lights are provided for four key nutrients: total fat, saturated fat, salt, and sugar. Red indicates 'fine for an occasional treat'; amber is an 'okay choice'; but choosing green is even better. The app also provides healthier lower-salt options to 'switch' to. Use and acceptability of the app will be assessed by a follow-up questionnaire at the end of the intervention period (weeks 6).
Intervention code [1] 288773 0
Lifestyle
Comparator / control treatment
Active control (no intervention)
Control group
Active

Outcomes
Primary outcome [1] 291458 0
Salt content of household food purchases (g/MJ) assessed using supermarket till receipts linked to a brand-specific food composition database (Nutritrack).
Timepoint [1] 291458 0
Change from baseline (weeks 1&2) to end of intervention (weeks 5&6)
Secondary outcome [1] 306824 0
Saturated fat content of household food purchases (g/MJ) assessed using supermarket till receipts linked to a brand-specific food composition database (Nutritrack).
Timepoint [1] 306824 0
Change from baseline (weeks 1&2) to end of intervention (weeks 5&6)
Secondary outcome [2] 306825 0
Energy content of household food purchases (kJ/kg) assessed using supermarket till receipts linked to a brand-specific food composition database (Nutritrack).
Timepoint [2] 306825 0
Change from baseline (weeks 1&2) to end of intervention (weeks 5&6)
Secondary outcome [3] 306826 0
Household food expenditure ($/fortnight) assessed using supermarket till receipts.
Timepoint [3] 306826 0
Change from baseline (weeks 1&2) to end of intervention (weeks 5&6)
Secondary outcome [4] 306827 0
Systolic blood pressure of household members with cardiovascular disease
Timepoint [4] 306827 0
Change between baseline (week 1) and end of intervention (week 6)
Secondary outcome [5] 306828 0
Urinary sodium excretion (mg/day) of household members with cardiovascular disease
Timepoint [5] 306828 0
Change between baseline (week 1) and end of intervention (week 6)
Secondary outcome [6] 306829 0
Household shopper use and acceptability of the SaltSwitch smart phone application assessed by a questionnaire at end of intervention (week 6). Participants in the intervention group will be asked to report how many times they used the app during each of the four weeks of the intervention period. They will also be asked how easy they found the app to use (Likert Scale);what they liked most, and least, about the app; ideas for improving the app; and whether they would recommend the app to others and why/why not (open ended questions).
Timepoint [6] 306829 0
End of intervention (week 6)
Secondary outcome [7] 306830 0
Ambulatory systolic blood pressure in participants with cardiovascular disease (sub study; n=50). Ambulatory blood pressure monitors will be worn continuously and will automatically measure blood pressure at half hour intervals during the day, and at hourly intervals during the night for a 24-hour period.
Timepoint [7] 306830 0
Change from baseline (week 1) to end of intervention (week 6)
Secondary outcome [8] 306831 0
All secondary outcomes except ambulatory blood pressure will also be measured in a sub group of main study participants (n=40; 20 intervention and 20 control) who will remain enrolled in the study for a further eight weeks to assess potential medium term impact of the intervention.
Timepoint [8] 306831 0
Change from baseline (weeks 1&2 or week 1 as appropriate) to end of intervention (weeks 5&6 or week 6 as appropriate)

Eligibility
Key inclusion criteria
Group 1: Participants with cardiovascular disease who are not the main food shopper for their household:
Previously diagnosed cardiovascular disease (history of prior acute coronary syndrome, revascularisation (prior PCI or CABG) or external angina)
Aged 40years and older

Group 2: Participants with cardiovascular disease who are also the main food shopper for their household (complete 50% or more of household shopping):
Previously diagnosed cardiovascular disease (history of prior acute coronary syndrome, revascularisation (prior PCI or CABG) or external angina)
Aged 40years and older
Shop at the supermarket for household food at least once per week spending $25 or more per household member
Own or have access to a smartphone for the next six weeks

Group 3: Participants who are main household shoppers only:
18 years or older
Shop at the supermarket for household food at least once per week spending $25 or more per household member
Own or have access to a smartphone for the next six weeks
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Group 1: Participants with cardiovascular disease who are not the main food shopper for their household:
Unable to provide informed consent
Suffered a cardiac event in the past three months (defined as hospitalization for heart attack, coronary artery revascularisation (CABG or stenting), stroke or heart failure
Previously been diagnosed with heart failure or severe valve disease (including severe aortic or mitral valve disease)
On a physician supervised diet or unwilling to make dietary changes
Taking medication that may lead to hyponaetraemia or acute build up of body water such as: frusemide, regular NSAID, or regular prednisone use

Group 2: Participants with cardiovascular disease who are also the main food shopper for their household (complete 50% or more of household shopping):
Unable to provide informed consent
Suffered a cardiac event in the past three months (defined as hospitalization for heart attack, coronary artery revascularisation (CABG or stenting), stroke or heart failure
Previously been diagnosed with heart failure or severe valve disease (including severe aortic or mitral valve disease)
On a physician supervised diet or unwilling to make dietary changes
Taking medication that may lead to hyponaetraemia or acute build up of body water such as: frusemide, regular NSAID, or regular prednisone use
Currently using the FoodSwitch smartphone app or planning to use it over the next six weeks
Do not return at least two till receipts and spend $25 or more per week per household member on grocery shopping over the baseline period

Group 3: Participants who are main household shoppers only:
Unable to provide informed consent
Currently using the FoodSwitch smartphone app or planning to use it over the next six weeks
Do not return at least two till receipts and spend $25 or more per week per household member on grocery shopping over the baseline period

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)
Participants will be enrolled by a Research Assistant via the telephone. Stratified block randomisation will take place manually at the end of baseline (end of week 2). The Research Assistant will use a set of pre-prepared envelopes to randomise households according to different stratum (ethnicity and age). Envelopes will be stored in a locked cabinet to which only the Research Assistant holds the key. Envelopes will be numbered and used in sequential order as per the randomisation list. When a new participant is ready to be randomised, the next envelope for that participants stratum will be used. The Research Assistant will telephone particiants to notify them of the group they have been randomised to.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A statistician will create a computer-generated randomisation list according to stratum (ethnicity and age) which will be used to prepare the randomisation envelopes. The randomisation list will be stored in a secure electronic folder, and the envelopes will be prepared by a Research Assistant not involved in the study.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
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 outside Australia
Country [1] 5817 0
New Zealand
State/province [1] 5817 0
Auckland

Funding & Sponsors
Funding source category [1] 288711 0
Charities/Societies/Foundations
Name [1] 288711 0
Heart Foundation of New Zealand
Address [1] 288711 0
9 Kalmia Street
Ellerslie
Auckland 1546
Country [1] 288711 0
New Zealand
Funding source category [2] 290684 0
University
Name [2] 290684 0
University of Auckland
Address [2] 290684 0
Tamaki Campus, The University of Auckland
261 Morrin Road, Glen Innes
Auckland 1142
New Zealand
Country [2] 290684 0
New Zealand
Primary sponsor type
University
Name
National Institute for Health Innovation, The University of Auckland
Address
Level 4, School of Population Health
Tamaki Campus
261 Morrin Road, Glen Innes
Auckland 1072

Private Bag 92019
Auckland Mail Centre
Auckland 1142
Country
New Zealand
Secondary sponsor category [1] 287414 0
None
Name [1] 287414 0
Address [1] 287414 0
Country [1] 287414 0
Other collaborator category [1] 277820 0
University
Name [1] 277820 0
The George Institute for Global Health
The University of Sydney
Address [1] 277820 0
PO Box M201
Missenden Road
NSW 2050
Australia
Country [1] 277820 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290548 0
University of Auckland Human Participants Ethics Committee
Ethics committee address [1] 290548 0
The University of Auckland
Private Bag 92019
Auckland 1142

Level 10, 49 Symonds Street
Auckland 1010

New Zealand
Ethics committee country [1] 290548 0
New Zealand
Date submitted for ethics approval [1] 290548 0
11/11/2013
Approval date [1] 290548 0
16/12/2013
Ethics approval number [1] 290548 0
010998

Summary
Brief summary
One in five New Zealanders 35-years and older already has cardiovascular disease (CVD). Following a diet low in salt is especially important for these people because it can reduce their blood pressure and chance of another heart event. However, many people with CVD find making heart healthy food choices confusing and difficult. A simple, free smartphone application (app) providing shoppers with interpretive nutrition labels could provide a novel solution. The aim of this trial is to determine the effect of the SaltSwitch smartphone app on the salt content of food purchases made by households with at least one member with diagnosed CVD. The primary hypothesis is that 4-weeks intervention with the SaltSwitch smartphone app will reduce the mean salt content of household food purchases compared with control.
Trial website
Trial related presentations / publications
Eyles H, McLean R, Neal B, Doughty R, Jiang Y, Ni Mhurchu C. Using mobile technology to support lower-salt food choices for people with cardiovascular disease: protocol for the SaltSwitch randomized controlled trial. BMC Public Health, 2014. 14(950). URL http://www.biomedcentral.com/1471-2458/14/950
Public notes

Contacts
Principal investigator
Name 46194 0
Dr Helen Eyles
Address 46194 0
National Institute for Health Innovation
School of Population Health, Tamaki Campus
The University of Auckland
261 Morrin Road, Glen Innes
Auckland 1072

Private Bag 92019
Auckland Mail Centre 1142
Country 46194 0
New Zealand
Phone 46194 0
+64 9 9234658
Fax 46194 0
+64 9 3731710
Email 46194 0
h.eyles@auckland.ac.nz
Contact person for public queries
Name 46195 0
Dr Helen Eyles
Address 46195 0
National Institute for Health Innovation
School of Population Health, Tamaki Campus
The University of Auckland
261 Morrin Road, Glen Innes
Auckland 1072

Private Bag 92019
Auckland Mail Centre 1142
Country 46195 0
New Zealand
Phone 46195 0
+6499234658
Fax 46195 0
+64 9 3731710
Email 46195 0
h.eyles@auckland.ac.nz
Contact person for scientific queries
Name 46196 0
Dr Helen Eyles
Address 46196 0
National Institute for Health Innovation
School of Population Health, Tamaki Campus
The University of Auckland
261 Morrin Road, Glen Innes
Auckland 1072

Private Bag 92019
Auckland Mail Centre 1142
Country 46196 0
New Zealand
Phone 46196 0
+64 9 9234658
Fax 46196 0
+64 9 3731710
Email 46196 0
h.eyles@auckland.ac.nz