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Trial registered on ANZCTR


Registration number
ACTRN12614000699662
Ethics application status
Approved
Date submitted
24/06/2014
Date registered
2/07/2014
Date last updated
2/07/2014
Type of registration
Retrospectively registered

Titles & IDs
Public title
The Healthy Heart Study: Investigating different ways of explaining cardiovascular disease risk to help people understand their risk and improve their lifestyle
Scientific title
The Healthy Heart Study: A randomised trial to investigate the effect of communicating 'heart age' versus 5-year absolute CVD risk on intention to change lifestyle, risk perceptions and behaviour amongst people eligible for CVD risk assessment
Secondary ID [1] 284863 0
Nil
Universal Trial Number (UTN)
Nil
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiovascular disease (CVD) risk 292264 0
Condition category
Condition code
Public Health 292618 292618 0 0
Health promotion/education
Cardiovascular 292619 292619 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Presentation of CVD risk assessment results as either 5-year absolute risk of a heart attack/stroke or heart age, in one of three visual formats (text only, text + bar graph, text + line graph showing projected risk over age):
Arm 1: percentage, text
Arm 2: percentage, text and bar graph
Arm 3: percentage, text and projected risk graph
Arm 4: heart age, text
Arm 5: heart age, text and bar graph
Arm 6: heart age, text and projected risk graph

The CVD risk assessment is conducted via computer, based on the 5-year Framingham risk equation used in Australian CVD prevention guidelines. The equation uses age, gender, current smoking/diabetes status, systolic blood pressure and total/HDL cholesterol ratio values to estimate the probability of a CVD event (e.g. heart attack or stroke) over the next 5 years. The assessment is based on participant responses for each risk factor via an online survey, and/or Australian averages for their age/gender if they indicate that they do not know their risk factor values.

The presentation formats are based on the following:

Percentage: the current absolute risk of a heart attack or stroke in the next 5 years

Heart age: the age at which a person of the same gender with 'ideal' risk factors (non-smoker, non-diabetic, systolic blood pressure equal to 120 mmHg, total/HDL cholesterol ratio equal to 4) would reach the current absolute risk result

Text: a brief description of the current and 'ideal' result, and how the current result could be improved if applicable
Percentage example: Your risk of a cardiovascular event in the next 5 years is 11%. If you stopped smoking and had lower levels of cholesterol and blood pressure, your risk would be 3%. You can reduce your blood pressure and cholesterol by quitting smoking, improving your diet and increasing physical activity.
Heart age example: Your heart age is 74, 24 years older than you. If you stopped smoking and had lower levels of cholesterol and blood pressure, your heart age would be 50, the same as your current age. You can reduce your blood pressure and cholesterol by quitting smoking, improving your diet and increasing physical activity.

Bar graph: displays the current result and the 'ideal' result as separate bars on the same graph

Projected risk graph: displays the current result and the 'ideal' result as separate lines on the same graph, showing how both will increase with age up to 74 years (the maximum age in the Framingham risk model)
Intervention code [1] 289669 0
Lifestyle
Intervention code [2] 289694 0
Behaviour
Intervention code [3] 289695 0
Prevention
Comparator / control treatment
5 year absolute CVD risk (arms 1-3)
Control group
Active

Outcomes
Primary outcome [1] 292458 0
Primary outcome: intention to change lifestyle (average of: improve diet, increase physical activity, stop smoking if applicable) assessed using an established 3 item Likert scale from the Theory of Planned Behavior for each lifestyle aspect

Timepoint [1] 292458 0
Timepoint: immediately post-intervention
Secondary outcome [1] 308996 0
Secondary Outcome 1: Correct recall of risk result assessed from open numerical response (compared to calculated risk result)
Timepoint [1] 308996 0
Timepoint: immediately post-intervention and at 2 week follow-up
Secondary outcome [2] 308997 0
Secondary Outcome 2: Basic risk perception assessed as the perceived risk category that the result indicated (low, moderate, or high risk of having a heart attack or stroke)
Timepoint [2] 308997 0
Timepoint: immediately post-intervention
Secondary outcome [3] 308998 0
Secondary Outcome 3: Emotional response assessed with an established 6 item Likert scale with positive (3 items) and negative (3 items) subscales
Timepoint [3] 308998 0
Timepoint: immediately post-intervention
Secondary outcome [4] 308999 0
Secondary Outcome 4: Perceived credibility assessed with an established 4 item Likert scale
Timepoint [4] 308999 0
Timepoint: immediately post-intervention
Secondary outcome [5] 309000 0
Secondary Outcome 5: Intention to see a GP regarding CVD risk assessed using an established 3 item Likert scale (from the Theory of Planned Behavior)
Timepoint [5] 309000 0
Timepoint: immediately post-intervention
Secondary outcome [6] 309001 0
Secondary Outcome 6: Comprehensive risk perception (numerical, verbal., comparative and feelings of risk) assessed with an established 4 item Likert scale
Timepoint [6] 309001 0
Timepoint: pre-intervention, immediately post-intervention and at 2 week follow-up
Secondary outcome [7] 309002 0
Secondary Outcome 7: Worry about CVD risk assessed with an established 2 item Likert scale
Timepoint [7] 309002 0
Timepoint: pre-intervention, immediately post-intervention and at 2 week follow-up
Secondary outcome [8] 309003 0
Secondary Outcome 8: Perceived timeline of CVD risk assessed with the 3 item Assessment of Illness Risk Representations (AIRR) timeline risk subscale
Timepoint [8] 309003 0
Timepoint: immediately post-intervention
Secondary outcome [9] 309004 0
Secondary Outcome 9: Perceived control of CVD risk assessed with the 3 item AIRR personal control subscale
Timepoint [9] 309004 0
Timepoint: immediately post-intervention
Secondary outcome [10] 309005 0
Secondary Outcome 10: Subjective understanding of CVD risk assessed with the 4 item AIRR coherence subscale
Timepoint [10] 309005 0
Timepoint: immediately post-intervention
Secondary outcome [11] 309006 0
Secondary Outcome 11: Information seeking based on an established method of clicking either of two CVD-related links at the end of the study
Timepoint [11] 309006 0
Timepoint: immediately post-intervention
Secondary outcome [12] 309007 0
Secondary Outcome 12: Smoking status (self reported)
Timepoint [12] 309007 0
Timepoint: 2 week follow-up
Secondary outcome [13] 309008 0
Secondary Outcome 13: Adequate physical activity based on the 2Q-PA scale for moderate and vigorous physical activity (self reported)
Timepoint [13] 309008 0
Timepoint: 2 week follow-up
Secondary outcome [14] 309009 0
Secondary Outcome 14: Adequate diet based on Australian guideline recommendations of 2 fruit servings and 5 vegetable servings per day (self reported)
Timepoint [14] 309009 0
Timepoint: 2 week follow-up
Secondary outcome [15] 309010 0
Secondary Outcome 15: Whether participants had or made a GP appointment regarding CVD risk in the last 2 weeks (self reported)
Timepoint [15] 309010 0
Timepoint: 2 week follow-up

Eligibility
Key inclusion criteria
1. eligible for CVD risk assessment (not already known to be at increased risk of CVD)

2. aged 45-64 years (equal 5 year age group quotas were set)

3. men and women (equal gender quotas were set)
Minimum age
45 Years
Maximum age
64 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Currently taking blood pressure or cholesterol-lowering medication

2. Diabetic

3. Already known to be at high risk of CVD based on additional criteria in the Australian guidelines:
* have had a heart attack, stroke or bypass surgery
* have moderate or severe chronic kidney disease (persistent proteinuria or estimated glomerular filtration rate < 45 mL/min/1.73 m2)
* have been diagnosed with familial hypercholesterolaemia
* systolic blood pressure (the larger blood pressure number) is higher than or equal to 180 mmHg
* diastolic blood pressure (the smaller blood pressure number) is higher than or equal to 110 mmHg
* serum total cholesterol is higher than 7.5 mmol/L

4. Being unable to read health-related information in English without help most of the time.

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants were randomised to one of the 6 CVD risk presentation formats after passing screening questions to ensure eligibility and quota sampling based on equal 5-year age and gender categories
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
An in-built algorithm randomly assigned a number between 1-6 to eligible participants, unless the quota limit had already been reached for their age/gender category
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Factorial
Other design features
2 (risk format: percentage, heart age) x 3 (visual format: text only, text + bar graph, text + projected risk) factorial design
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
The a priori sample size calculation indicated that 85 participants per group, totalling 510 participants, would provide 90% power to detect a moderate effect size of d=0.5 (standardised difference) in the primary outcome of intention to change lifestyle, assuming a two-sided alpha of 0.05. We aimed to recruit 20% more cases to account for potential dropout.
The Mann-Whitney test (non-parametric) was used to compare groups across continuous outcomes, and the Fisher's exact test was applied to categorical outcomes. We further explored the dependence of the results on participants’ calculated heart age result (younger/same versus older than current age) by testing an interaction using linear and multinomial models for continuous and categorical outcomes, respectively. The significance level for all hypothesis tests was set at 0.05.

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] 289477 0
Charities/Societies/Foundations
Name [1] 289477 0
National Heart Foundation of Australia
Address [1] 289477 0
Level 3, 80 William Street
East Sydney NSW 2011
Country [1] 289477 0
Australia
Funding source category [2] 289478 0
Government body
Name [2] 289478 0
National Health and Medical Research Council (NHMRC)
Address [2] 289478 0
Level 1
16 Marcus Clarke Street
Canberra ACT 2601
Country [2] 289478 0
Australia
Primary sponsor type
University
Name
The University of Sydney
Address
The University of Sydney, Sydney, NSW 2006
Country
Australia
Secondary sponsor category [1] 288163 0
None
Name [1] 288163 0
Address [1] 288163 0
Country [1] 288163 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 291235 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 291235 0
Level 6, Jane Foss Russell
The University of Sydney
NSW 2006 Australia
Ethics committee country [1] 291235 0
Australia
Date submitted for ethics approval [1] 291235 0
Approval date [1] 291235 0
25/11/2013
Ethics approval number [1] 291235 0
2013/914

Summary
Brief summary
Who is it for?
Participants were eligible to join this study if they were aged between 45-64 years and not already known to be at increased risk of cardiovascular disease (CVD).

Study details:
Participants completed an online CVD risk assessment and were randomly (by chance) allocated to receive their results as either their 'heart age' or the equivalent percentage risk of a heart attack or stroke over the next 5 years, using three different visual formats. The researchers investigated how different ways of explaining CVD risk affected a range of psychological and behavioural outcomes, including intention to change lifestyle, risk perceptions, and behaviour change after 2 weeks.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 49442 0
A/Prof Kirsten McCaffery
Address 49442 0
Rm 301, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 49442 0
Australia
Phone 49442 0
+61 2 9351 7220
Fax 49442 0
+61 2 9351 5049
Email 49442 0
kirsten.mccaffery@sydney.edu.au
Contact person for public queries
Name 49443 0
A/Prof Kirsten McCaffery
Address 49443 0
Rm 301, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 49443 0
Australia
Phone 49443 0
+61 2 9351 7220
Fax 49443 0
+61 2 9351 5049
Email 49443 0
kirsten.mccaffery@sydney.edu.au
Contact person for scientific queries
Name 49444 0
A/Prof Kirsten McCaffery
Address 49444 0
Rm 301, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 49444 0
Australia
Phone 49444 0
+61 2 9351 7220
Fax 49444 0
+61 2 9351 5049
Email 49444 0
kirsten.mccaffery@sydney.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