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Trial registered on ANZCTR


Registration number
ACTRN12617000558325
Ethics application status
Approved
Date submitted
28/03/2017
Date registered
21/04/2017
Date last updated
21/04/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Can a smart phone application assist in reducing dietary phosphate and sodium intake?
Scientific title
Can healthy individuals using a smart phone application reduce their dietary phosphate or sodium intake as well as, or better than, healthy individuals provided with standard dietetic advice
Secondary ID [1] 286049 0
None
Universal Trial Number (UTN)
U1111-1166-5130
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Dietary sodium and phosphate intake

293944 0
Condition category
Condition code
Diet and Nutrition 294243 294243 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 294327 294327 0 0
Normal metabolism and endocrine development and function
Public Health 294328 294328 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
We will recruit healthy volunteers to the study.

After providing potential participants with study information and receiving their informed consent, we will obtain urine for a urinalysis, check a blood pressure and assess for any history of kidney disease or use of medications likely to influence urine sodium or phosphate values. Participants with a normal urinalysis, blood pressure and without any history of kidney disease or use of those medications will meet entry criteria for the study.

Participants will then be randomly allocated to either an 'intervention group' or a control 'usual care group'.

All participants then undergo baseline investigations: Participants will be asked to maintain a food diary for 3 days to assess baseline dietary sodium and phosphate intake.
Body mass index (BMI) will be assessed. A baseline 24 hour urine sample will be collected for urine volume, creatinine, sodium and phosphate.

We will then ask all the participants to 'moderately' reduce their sodium and phosphate intake for the next 2 weeks. For the purposes of this study, ‘moderate’ reduction refers to the dietary sodium and phosphate targets used as therapeutic targets for dietary modification for people with end stage kidney disease. These targets are based on systematic reviews of dietary trials. A moderate reduction here refers to a therapeutic diet with less than 100mmol of Na per day and less than 1000mg of phosphate per day.

To achieve this moderate reduction, all participants will be provided with a dietary leaflet, which provides advice on strategies to achieve the reduction, The dietary leaflet used in this study is identical to the leaflet used in clinical care in the Illawarra Shoalhaven Local Health District.

Further instruction will occur via a telephone interview with a trained dietician in the following way; Participants will be provided with feedback about their baseline diet and provided with individualised advice on how to reduce dietary sodium and phosphate to the target levels. . This intervention replicates what would happen in real life clinical care conditions with a patient with chronic kidney disease if they were seen by a dietician as an outpatient. The baseline interview with the dietician is expected to be no more than 1 hour, which replicates the usual time taken for an initial interview with a renal dietician in clinical care.

Intervention group: Participants allocated to the intervention group will be instructed on the use of a dietary smart phone application (app), which they will be able to use to monitor their sodium and phosphate targets. The app is an extension to an existing smart phone app that uses the foodworks TM database, This database accesses Australian food products and is widely used by dieticians. The app will include information on the sodium and phosphate content of common processed and unprocessed foods and can be used to look up the content of packaged foods using the food's bar code. The app works out the intake values, based on food varieties and brands entered by the participant or from the bar code on packaged foods, using the camera on the smart phone. Instruction on use of the app will be provided by one of the researchers (who is not a dietician) and is expected to take up to 30 minutes. Participants will be encouraged to use the app to enter their food choices on a daily basis. Once entered for the 1st day, it is usually simple to add modifications to a recurring daily diet. Participants will also be encouraged to use the app to look up the sodium and phosphate content of foods if they are unsure whether the food has a high or low sodium or phosphate content.
No additional strategies will be used to increase adherence in the intervention group, as this study is a pragmatic study replicating real life conditions i.e. in future studies, if this protocol were used for patients with kidney disease, additional support to increase adherence would not be generally available.

We will ask all participants to perform a second 24 hour urine collection after 2 weeks.
Participants are also asked to complete a post intervention self report questionnaire to assess intervention adherence and ease of compliance to the suggested dietary modifications.
Intervention code [1] 290968 0
Lifestyle
Comparator / control treatment
We will recruit healthy volunteers to the study.

After providing potential participants with study information and receiving their informed consent, we will obtain urine for a urinalysis, check a blood pressure and assess for any history of kidney disease or use of medications likely to influence urine sodium or phosphate values. Participants with a normal urinalysis, blood pressure and without any history of kidney disease or use of those medications will meet entry criteria for the study.
Participants will then be randomly allocated to either an 'intervention group' or a control 'usual care group'.

All participants then undergo baseline investigations: Participants will be asked to maintain a food diary for 3 days to assess baseline dietary sodium and phosphate intake.
Body mass index (BMI) will be assessed. A baseline 24 hour urine sample will be collected for urine volume, creatinine, sodium and phosphate.

We will then ask all the participants to 'moderately' reduce their sodium and phosphate intake for the next 2 weeks. For the purposes of this study, ‘moderate’ reduction refers to the dietary sodium and phosphate targets used as therapeutic targets for dietary modification for people with end stage kidney disease. These targets are based on systematic reviews of dietary trials. A moderate reduction here refers to a therapeutic diet with less than 100mmol of sodium per day and less than 1000mg of phosphate per day.
To achieve this moderate reduction, all participants will be provided with a dietary leaflet, which provides advice on strategies to achieve the reduction, The dietary leaflet used in this study is identical to the leaflet used in clinical care in the Illawarra Shoalhaven Local Health District.

Further instruction will occur via a telephone interview with a trained dietician in the following way; Participants will be provided with feedback about their baseline diet and provided with individualised advice on how to reduce dietary sodium and phosphate to the target levels. . This intervention replicates what would happen in real life clinical care conditions with a patient with chronic kidney disease if they were seen by a dietician as an outpatient. The baseline interview with the dietician is expected to be no more than 1 hour, which replicates the usual time taken for an initial interview with a renal dietician in clinical care.

Control group: No additional strategies will be used to increase adherence in the control group, as this study is a pragmatic study replicating real life conditions i.e. in future studies, if this protocol were used for patients with kidney disease, additional support to increase adherence would not be generally available. .

We will ask all participants to perform a second 24 hour urine collection after 2 weeks. Participants are also asked to complete a post intervention self report questionnaire to assess intervention adherence and ease of compliance to the suggested dietary modifications.

Control group
Active

Outcomes
Primary outcome [1] 294044 0
Within group change in 24 hour urinary sodium values.


Timepoint [1] 294044 0
The time point at which we measuring this outcome is at 2 weeks.
Primary outcome [2] 294128 0
Within group change in 24 hour urinary phosphate values.

Timepoint [2] 294128 0
The time point at which we measuring this outcome is at 2 weeks.
Secondary outcome [1] 312404 0
Between group comparison of ease of dietary compliance for the standard advice and the smart phone app. will be assessed by questionnaire designed specifically for this study.
This questionnaire contains:
Eleven question on acceptability and useability of the three day food diary for all participants.
Five questions on compliance for all participants .
Fourteen question s about ease of use of the app for intervention group users only.
Responses will be completed on a 5-point Likert scale.
In addition, there will be 5 free text questions asking for comments in which participants could provide opinions or describe experiences.
Timepoint [1] 312404 0
The time point at which we measuring this outcome is at 2 weeks.

Eligibility
Key inclusion criteria
This study requires healthy individuals to participate. The participants will be recruited by advertising the project at the University of Notre Dame Sydney. It is expected that medical students will be the participants.
Minimum age
18 Years
Maximum age
50 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
The exclusion criteria are any participants: using medication likely to affect their urinary sodium or phosphate levels (such as diuretics or calcium supplements), or with an abnormal baseline urinalysis (UA) for protein, glucose, blood, white cells or albumin), an abnormal resting blood pressure or a history of kidney disease.

These participants will only be excluded to avoid confounding factors in their results.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Block randomisation will be used for allocation of the participants to either of the 2 dietary interventions (AABB, ABAB, ABBA, BABA, BAAB, BBAA).

For allocation, contact will be made by telephone with the holder of the allocation schedule who will be off-site.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Block randomisation
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
Participants cannot be blinded to use of the app or standard dietetic management.
All data from the study will be entered to a statistical database in a deidentified fashion by a nurse blinded to the allocation of intervention.
The deidentified data will be analysed by the researchers blinded to allocation of the intervention until analyses are completed.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
SPPS will be used for analyses. Data will be tested for normal distribution and mean values will be compared using either Student T-tests (parametric) or Mann-Whitney U or Wilcoxon tests (non parametric). Differences from baseline to 2 weeks will be compared using Mann Whitney, and within group changes from baseline will be assessed using the Wilcoxon signed rank test. Correlations will be assessed using the Spearman rank correlation for non parametric data. P-values <0.05 will be considered statistically significant. The sample size to detect a statistically significant change from baseline to 2
weeks in phosphate with an expected effect size of 0.8 and power 0.95
p<0.05 is 10 participants..
The study will not aim to assess between group differences in urinary sodium, because the estimated sample size required is 123 participants in each group, which is outside the capabilities and budget of the research.

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)
NSW
Recruitment hospital [1] 3364 0
Auburn Hospital & Community Health Services - Auburn
Recruitment postcode(s) [1] 9149 0
2144 - Auburn

Funding & Sponsors
Funding source category [1] 296074 0
Hospital
Name [1] 296074 0
Westmead Hospital
Country [1] 296074 0
Australia
Primary sponsor type
Government body
Name
Western Sydney Local Health District
Address
WSLHD HREC
Westmead Hospital,
Cnr Hawesbury Road and Darcy Road
Westmead, NSW, 2145
Country
Australia
Secondary sponsor category [1] 295058 0
University
Name [1] 295058 0
University of Notre Dame, Australia
Address [1] 295058 0
32 Mouat St, Fremantle WA 6160

PO Box 1225, Fremantle, WA 6959
Country [1] 295058 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292222 0
Western Sydney Local Health District HREC
Ethics committee address [1] 292222 0
Ethics committee country [1] 292222 0
Australia
Date submitted for ethics approval [1] 292222 0
11/02/2015
Approval date [1] 292222 0
11/05/2015
Ethics approval number [1] 292222 0
(ECOO152)

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 54134 0
Prof Grahame Elder
Address 54134 0
Department of Renal Medicine,
Westmead Hospital, Cnr Darcy and Hawesbury Roads
Westmead, NSW, 2145
Country 54134 0
Australia
Phone 54134 0
+612 98456962
Fax 54134 0
+61 2 96339351
Email 54134 0
g.elder@garvan.org.au
Contact person for public queries
Name 54135 0
Grahame Elder
Address 54135 0
Department of Renal Medicine,
Westmead Hospital, Cnr Darcy and Hawesbury Roads
Westmead, NSW, 2145
Country 54135 0
Australia
Phone 54135 0
+61 2 98456962
Fax 54135 0
+61 2 96339351
Email 54135 0
g.elder@garvan.org.au
Contact person for scientific queries
Name 54136 0
Grahame Elder
Address 54136 0
Department of Renal Medicine,
Westmead Hospital, Cnr Darcy and Hawesbury Roads
Westmead, NSW, 2145
Country 54136 0
Australia
Phone 54136 0
+61 2 98456962
Fax 54136 0
+61 2 96339351
Email 54136 0
g.elder@garvan.org.au

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseRole of dietary phosphate restriction in chronic kidney disease.2018https://dx.doi.org/10.1111/nep.13188
N.B. These documents automatically identified may not have been verified by the study sponsor.