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Trial registered on ANZCTR


Registration number
ACTRN12621000096853
Ethics application status
Approved
Date submitted
14/12/2020
Date registered
1/02/2021
Date last updated
1/11/2022
Date data sharing statement initially provided
1/02/2021
Date results provided
1/11/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Web-based low carbohydrate dietary intervention for adults with type 2 diabetes
Scientific title
Effect of a web-based low carbohydrate dietary intervention on HbA1c levels in adults with type 2 diabetes: a randomised controlled trial
Secondary ID [1] 302961 0
None
Universal Trial Number (UTN)
U1111-1262-4033
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 diabetes 319998 0
Condition category
Condition code
Metabolic and Endocrine 317927 317927 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention participants will receive a 16 week automated web-based low carbohydrate dietary intervention, alongside their standard care. According to the Royal Australian College of General Practice (2016), standard care for patients with type 2 diabetes typically includes routine appointments with their physician to monitor glycaemic control, diabetes complications and other health parameters.

The web-based intervention consists of theoretically-grounded, weekly structured behaviour change modules that guide the participants to consume a low carbohydrate diet, encouraging participants to consume between 50-100 grams of carbohydrates per day, or otherwise defined as carbohydrate intake <26% total energy intake (Huntriss et al. 2018). Participants will be provided with login access to the intervention web-platform, which contains a range of on demand resources and delivers the weekly modules sequentially, on a weekly basis over the 16 weeks. Weekly modules encourage dietary behaviour change by providing education about and comparisons of different carbohydrate foods, information about type 2 diabetes, low carbohydrate eating guidelines, menu planning tips, food and beverage choices, recipes, food preparation tips, cooking demonstrations, eating out, menu examples, and other resources. Weekly modules consist of short videos, brief summaries and links to additional resources. During the 16-week intervention, twice weekly email notifications are sent to participants to notify them of new modules and to prompt usage of intervention content. With the weekly modules being sequentially delivered, alongside email reminders, it is estimated participants will login to the website once per week to engage with videos and other content.

Following the intervention, a mixed-methods process evaluation will explore website usage and engagement, assessing quantitative data from user-experience questionnaires, detailed website statistics and email usage rates, in addition to capturing qualitative data. Semi-structured interviews will be conducted with a maximum of 20 intervention participants (n=8-20). Selection for qualitative interviews will be based on the first 20 participants who provided consent and are available to be interviewed post-intervention. Jedha Dening will conduct the interviews via phone with audio recording, by permission. Qualitative data analysis will be conducted independently by a third-party researcher using Nvivo software.
Intervention code [1] 319247 0
Lifestyle
Comparator / control treatment
The control group is standard care, as defined above.
Control group
Active

Outcomes
Primary outcome [1] 325934 0
The primary outcome is mean difference of change in haemoglobin A1c (HbA1c) from baseline at week 16 between intervention and control, assessed using the Nutripath Integrative Pathology Services.
Timepoint [1] 325934 0
Baseline and week 16
Secondary outcome [1] 389593 0
Dietary intake (food, beverages and supplements), assessed with 24-hour food recall (24HR) submitted via study-specific online questionnaire, analysed using FoodWorks professional nutrition analysis software for Australia and New Zealand.
Timepoint [1] 389593 0
Baseline and week 16
Secondary outcome [2] 389594 0
Self-efficacy, assessed by self-report using the Diabetes Management Self-Efficacy Scale questionnaire, entered via Qualtrics online form
Timepoint [2] 389594 0
Baseline and week 16
Secondary outcome [3] 389595 0
Assess body mass index using participant self-reported weight and height measurements, submitted via study-specific online questionnaire with free text entry
Timepoint [3] 389595 0
Weight and height baseline, weight only week 16
Secondary outcome [4] 389686 0
Anti-diabetes medication and dosages, assessed by participant self-report, study-specific online questionnaire with free text entry
Timepoint [4] 389686 0
Baseline and week 16
Secondary outcome [5] 389687 0
Diabetes-related comorbidities, assessed by participant self-report, study-specific online questionnaire with checkbox selection
Timepoint [5] 389687 0
Baseline and week 16
Secondary outcome [6] 389688 0
Website utilisation patterns and engagement (intervention group only), assessed by website analytics and email usage rates for frequency, intensity and duration metrics for each week of the 16-week intervention
Timepoint [6] 389688 0
Weeks 1-16
Secondary outcome [7] 389689 0
Participants experience of the intervention (intervention group only), assessed by self-report using the User Engagement Scale short form/Honeycomb Model questionnaire, entered via Qualtrics online form
Timepoint [7] 389689 0
Week 16
Secondary outcome [8] 389690 0
Participants experience of the intervention (intervention group only), assessed via qualitative semi-structured individual interviews in a purposive sample of intervention participants
Timepoint [8] 389690 0
Week 16

Eligibility
Key inclusion criteria
Adults aged 40-89 years with non-insulin dependent type 2 diabetes. Participants will need to be based in Australia, have access to the internet, an active email address, able to read and understand English, and provide informed consent.
Minimum age
40 Years
Maximum age
89 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Participants will be excluded if they have prediabetes, type 1 diabetes, or gestational diabetes, are pregnant or lactating, have or are at risk of disordered eating, have been diagnosed with cardiovascular or renal disease, have terminal disease or severe complications that may compromise their ability to participate (proliferative retinopathy, severe neuropathy, cancer, end stage renal disease/serious kidney disease), have had bariatric surgery, are vegan or vegetarian, are currently on or have taken a weight loss program in the past 3 months, are participating in other clinical studies

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)
The study statistician will be the holder of the allocation schedule off-site.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Block randomisation with varying random block sizes and stratified by age and gender.
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
All data will be imported into Stata for quantitative analysis. Baseline characteristics will be presented using descriptive statistics. The mean and standard deviation, or median and range will be used to describe continuous variables. Frequencies and/or percentages will be used to describe categorical variables. Intervention effects (i.e. mean difference between intervention and control group) at 16 weeks will be evaluated by implementing a ANCOVA model for each outcome with the 16-week value of the outcome as dependent variable, and treatment group and baseline outcome score as independent variables, and adjusting for stratification variables (age and gender). A multiple imputation technique with missing at random assumption will be used to impute missing data due to drop outs or withdrawals in order to comply with the intention to treat (ITT) approach. Sensitivity analysis will be performed to evaluate missing at random assumption for missing observation pattern. Subgroup analysis will be conducted with duration of diabetes and gender. For duration of diabetes, a median split will be used to define subgroups. p-value 0.05 will be used as the level of significance for the primary outcome and all secondary outcomes. Cohen’s D effect size will be calculated and reported. For all continuous outcomes, data will be explored for deviation from the normal distribution assumptions, and if necessary, transformation of data (e.g. log transformation) or non-parametric approach may be considered.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
2/02/2021
Actual
29/03/2021
Date of last participant enrolment
Anticipated
31/12/2021
Actual
1/11/2021
Date of last data collection
Anticipated
30/04/2022
Actual
21/02/2022
Sample size
Target
100
Accrual to date
Final
98
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 307380 0
University
Name [1] 307380 0
Deakin University
Country [1] 307380 0
Australia
Primary sponsor type
Individual
Name
Dr Shariful Islam
Address
Institute for Physical Activity and Nutrition Research
Deakin University
221 Burwood Highway
Burwood VIC 3125
Country
Australia
Secondary sponsor category [1] 308036 0
None
Name [1] 308036 0
Address [1] 308036 0
Country [1] 308036 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 307466 0
Deakin University Health Research Ethics Committee
Ethics committee address [1] 307466 0
Ethics committee country [1] 307466 0
Australia
Date submitted for ethics approval [1] 307466 0
19/10/2020
Approval date [1] 307466 0
04/01/2021
Ethics approval number [1] 307466 0
2020-349

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

Contacts
Principal investigator
Name 107334 0
Dr Shariful Islam
Address 107334 0
Institute for Physical Activity and Nutrition Research
Deakin University
221 Burwood Highway
Burwood VIC 3125
Country 107334 0
Australia
Phone 107334 0
+61 3 924 68393
Fax 107334 0
Email 107334 0
[email protected]
Contact person for public queries
Name 107335 0
Jedha Dening
Address 107335 0
Institute for Physical Activity and Nutrition Research
Deakin University
221 Burwood Highway
Burwood VIC 3125
Country 107335 0
Australia
Phone 107335 0
+61 3 924 68393
Fax 107335 0
Email 107335 0
[email protected]
Contact person for scientific queries
Name 107336 0
Shariful Islam
Address 107336 0
Institute for Physical Activity and Nutrition Research
Deakin University
221 Burwood Highway
Burwood VIC 3125
Country 107336 0
Australia
Phone 107336 0
+61 3 924 68393
Fax 107336 0
Email 107336 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


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
9992Study protocol  [email protected]



Results publications and other study-related documents

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

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseRandomised controlled trial of a web-based low carbohydrate diet intervention for adults with type 2 diabetes: the T2Diet study protocol.2022https://dx.doi.org/10.1136/bmjopen-2021-054594
N.B. These documents automatically identified may not have been verified by the study sponsor.