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Trial registered on ANZCTR


Registration number
ACTRN12618000527268
Ethics application status
Approved
Date submitted
26/03/2018
Date registered
10/04/2018
Date last updated
7/07/2021
Date data sharing statement initially provided
11/03/2019
Date results information initially provided
24/02/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Dietary intervention for age-related macular degeneration patients
Scientific title
Implementing and evaluating a telephone-delivered dietary intervention for age-related macular degeneration patients
Secondary ID [1] 294242 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Age-related macular degeneration 306921 0
Condition category
Condition code
Eye 306018 306018 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This two-year project will implement and evaluate a telephone-delivered dietary behaviour intervention for AMD patients, aiming to promote a diet that is rich in vegetables, fruits, fish, low-glycaemic index foods and the appropriate use of antioxidant supplements. It will have a two-pronged approach: (1) ensures the correct information on diet and AMD is passed onto the patient; and (2) an accredited practicing dietitian (APD) provides telephone coaching and support to facilitate and enhance the patients’ adoption of dietary recommendations. Participants will be randomised to one of two groups - intervention or wait-list control

Participants in the intervention group will be mailed a workbook that contains information on dietary behaviours promoting optimal macula health; information on goal setting; problem-solving; self-rewards; positive self-talk; relapse, and action plans. They will be scheduled to receive weekly phone calls over 4 months from the counsellor (accredited practicing dietitian, APD). The initial consultation over the phone will be about 30-45 mins in duration and subsequent weekly follow up phone calls will be about 15-20 minutes in duration. Content of calls will be tailored to participants’ stage of change. For all stages, there will be a discussion of the diet-disease relationship, as well identification of appropriate goals, and arrangement of follow up calls. Participants in a ‘pre-contemplative’ or contemplative’ stage, will participate in calls that focus on self-reevaluation, environmental re-evaluation, and general dietary advice e.g. key food groups, and recommended serves. Participants in the ‘preparation’, and ‘action’ stages, will be engaged in calls that focus on goal setting, strategies to achieving goals, and discussion of barriers to change.

A prospective, randomised trial design will be used to determine pre- and post-intervention changes in dietary intakes and behaviours. Intakes will be assessed using a validated 145-item Food Frequency Questionnaire (FFQ) and a Dietary Behaviour Questionnaire (DBQ). The FFQ and DBQ will be used at baseline, and 6 months post-intervention, while the DBQ alone will be used at the end of the 4-month intervention, and at 3 months. The intervention and controls group will be compared based on post-intervention intake levels and behaviour change.

All participant contacts will be systematically tracked to allow for reporting on: the number of call attempts, completed calls (or ‘dose’ of intervention received), number of calls completed at the scheduled time (versus via call back), reasons for missed calls, and call duration. The call content will be tracked via checklists completed after each call allowing for reporting on the extent to which the intervention content is delivered per protocol, and the percentage of participants setting goals for dietary behaviours. At the end of the intervention, participants will be asked a set of questions that will help us understand their experience of the telephone coaching, including if they found it useful and whether they would recommend this to a friend. Using a Likert scale ranging from 0-5, they will be able to rate their satisfaction with the overall intervention content and the dietary messages provided, as well as their adherence to the dietary advice provided by the dietitian. Finally, they will be able to detail any suggestions on how this intervention could be improved.

We will carry out ‘within trial’ cost-effectiveness analysis in which outcomes will be measured as clinically relevant improvements as per the FFQ and DBQ. The perspective taken will be that of health provider. We will collect data prospectively on the costs to deliver the intervention program (telephone calls, staff time, training, mail-outs, and any other intervention resources).
Intervention code [1] 300537 0
Lifestyle
Intervention code [2] 300538 0
Behaviour
Intervention code [3] 300539 0
Prevention
Comparator / control treatment
Control participants will be similarly assessed to intervention participants i.e. assessed at baseline by completing the same questionnaire covering demographic, medical, and eye health questions, as well as an lifestyle questions, FFQ and DBQ. They will also be followed up 3- and 6-months post-intervention period by completing the lifestyle questions, FFQ and DBQ. Hence, control participants will be assessed 3 times in total - at baseline, 3- and 6-months post-intervention. All assessments will be self-administered.

After each assessment, controls will be mailed a 1-page letter thanking them for their continued participation. They will also receive newsletters with general health tips, and relevant off-the-shelf brochures. These newsletters and brochures will be provided as a once-off, after randomisation. The dietitian/ study staff will follow up with participants, immediately after the intervention to thank them for their involvement in the study and remind them of the follow up assessments that need to be completed. All control participants will be offered the telephone coaching at the completion of the project if it proves to have been effective after evaluation.
Control group
Active

Outcomes
Primary outcome [1] 305052 0
Change in total vegetable intake over the 6 months follow-up. This is is a composite outcome that will be assessed via data collected from FFQs and DBQs (baseline and follow up), as well as through a descriptive analysis of the dietitian’s notes throughout the intervention period.
Timepoint [1] 305052 0
Assessed at baseline, end of 4-month intervention, 3 months post-intervention and 6 months post-intervention (primary timepoint),
Secondary outcome [1] 343998 0
Change in total intake of dark green leafy vegetables over the 6-month follow-up. This is a composite outcome that will be assessed via data collected from FFQs and DBQs (baseline and follow up), as well as through a descriptive analysis of the dietitian’s notes throughout the intervention period.
Timepoint [1] 343998 0
Assessed at baseline, end of 4-month intervention, 3 months post-intervention and 6 months post-intervention.
Secondary outcome [2] 343999 0
Change in total intake of fish over the 6-month follow-up. This is a composite outcome that will be assessed via data collected from FFQs and DBQs (baseline and follow up), as well as through a descriptive analysis of the dietitian’s notes throughout the intervention period.
Timepoint [2] 343999 0
Assessed at baseline, end of 4-month intervention, 3 months post-intervention and 6 months post-intervention.
Secondary outcome [3] 344000 0
Appropriate use of antioxidant supplements, This is a composite outcome that will be assessed via data collected from FFQs and DBQs (baseline and follow up), as well as through a descriptive analysis of the dietitian’s notes throughout the intervention period.
Timepoint [3] 344000 0
Assessed at baseline, end of 4-month intervention, 3 months post-intervention and 6 months post-intervention.
Secondary outcome [4] 345042 0
Change in total intake of fruits over the 6-month follow-up. This is a composite outcome that will be assessed via data collected from FFQs and DBQs (baseline and follow up), as well as through a descriptive analysis of the dietitian’s notes throughout the intervention period.
Timepoint [4] 345042 0
Assessed at baseline, end of 4-month intervention, 3 months post-intervention and 6 months post-intervention.
Secondary outcome [5] 345043 0
Acceptability of and satisfaction with the dietary intervention. This will be assessed through a set of questions that will help us understand their experience of the telephone coaching. Also, a Likert scale ranging from 0-5, will indicate participants' satisfaction with the overall intervention content and the dietary messages provided, as well as their adherence to the dietary advice provided by the dietitian.
Timepoint [5] 345043 0
After receiving the intervention i.e. at the end of the 4-month intervention period.
Secondary outcome [6] 345044 0
Cost-effectiveness of the trial. This will be assessed through outcomes measured as clinically relevant improvements as per the FFQ and DBQ. The perspective taken will be that of health provider. We will collect data prospectively on the costs to deliver the intervention program (telephone calls, staff time, training, mail-outs, and any other intervention resources).
Timepoint [6] 345044 0
At the end of the two-year study period.

Eligibility
Key inclusion criteria
Inclusion criteria will include any patient diagnosed with age-related macular degeneration and who can read English.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria are: (a) lack sufficient fluency in spoken English to engage in the intervention; (b) unwilling to actively engage in the telephone-delivered coaching sessions over the 4 months; (c) inability to give informed consent.

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 design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
23/04/2018
Actual
12/06/2018
Date of last participant enrolment
Anticipated
29/03/2019
Actual
2/07/2019
Date of last data collection
Anticipated
31/12/2020
Actual
26/02/2021
Sample size
Target
140
Accrual to date
Final
155
Recruitment in Australia
Recruitment state(s)
ACT,NSW,QLD,WA,VIC

Funding & Sponsors
Funding source category [1] 298881 0
Government body
Name [1] 298881 0
National Health and Medical Research Council
Country [1] 298881 0
Australia
Primary sponsor type
University
Name
University of Sydney
Address
The University of Sydney
Camperdown
NSW 2006
Country
Australia
Secondary sponsor category [1] 298094 0
None
Name [1] 298094 0
Address [1] 298094 0
Country [1] 298094 0
Other collaborator category [1] 280002 0
Other Collaborative groups
Name [1] 280002 0
Westmead Institute for Medical Research
Address [1] 280002 0
176 Hawkesbury Rd
Westmead NSW 2145
Country [1] 280002 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299823 0
University of Sydney Human Research Ethics Committee
Ethics committee address [1] 299823 0
Level 3, Administration Building (F23)
University of Sydney NSW 2006
Ethics committee country [1] 299823 0
Australia
Date submitted for ethics approval [1] 299823 0
Approval date [1] 299823 0
22/03/2018
Ethics approval number [1] 299823 0

Summary
Brief summary
Age-related macular degeneration (AMD) is the principal cause of blindness in Australia. Therefore, all options to slow down the rate of development and progression of AMD are critical. After smoking, nutrition is the key modifiable risk factor to reduce AMD incidence and no other preventative treatments are currently available. Despite the strong evidence-base, there remains confusion among patients and practitioners about what foods should be consumed in order to maximise absorption of useful nutrients and what supplements to take. An intervention aiming to promote a diet that is regularly rich in vegetables, fruits, and fish, will ensure good macula health. Also, the intervention should appropriately advise on supplementation in the absence of sufficient dietary intake of long-chain omega-3 fats and key micronutrients (lutein/zeaxanthin, zinc, vitamins C and E). However, translation efforts in AMD have so far focused on screening and drug or laser treatments. Therefore, the proposed study will address this evidence-practice gap, by implementing and evaluating a telephone-delivered dietary behaviour intervention targeting patients with AMD. An economic assessment to measure the cost-effectiveness of the intervention will be undertaken. This type of nutrition-focused healthcare is currently not considered in the long-term management of AMD, and represents the first empirical evaluation of a telehealth application encouraging adherence to dietary recommendations for AMD. Further, wide-scale delivery of this intervention has potential to lower the risk of progression to blinding, late-stage AMD in high risk patients.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 81678 0
Prof Bamini Gopinath
Address 81678 0
Australian Hearing Hub
16 University Avenue
Macquarie University NSW 2109
Country 81678 0
Australia
Phone 81678 0
+61 2 9850 8962
Fax 81678 0
Email 81678 0
[email protected]
Contact person for public queries
Name 81679 0
Diana Tang
Address 81679 0
Centre for Vision Research
Westmead Institute for Medical Research
Level 3
PO Box 412
Westmead NSW 2145
Country 81679 0
Australia
Phone 81679 0
+61286273337
Fax 81679 0
Email 81679 0
[email protected]
Contact person for scientific queries
Name 81680 0
Bamini Gopinath
Address 81680 0
Australian Hearing Hub
16 University Avenue
Macquarie University NSW 2109
Country 81680 0
Australia
Phone 81680 0
+61 2 9850 8962
Fax 81680 0
Email 81680 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
IPD not available at this stage as data is incomplete. IPD may be available on request to A/Prof Bamini Gopinath at the conclusion of the study in 12-18 months time.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
1571Study protocol    374655-(Uploaded-11-03-2019-13-27-10)-Study-related document.pdf



Results publications and other study-related documents

Documents added manually

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseDietary intervention in patients with age-related macular degeneration: Protocol for a randomised controlled trial.2019https://dx.doi.org/10.1136/bmjopen-2018-024774
N.B. These documents automatically identified may not have been verified by the study sponsor.