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Trial registered on ANZCTR


Registration number
ACTRN12618001700224
Ethics application status
Approved
Date submitted
9/10/2018
Date registered
16/10/2018
Date last updated
29/11/2018
Date data sharing statement initially provided
29/11/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
How doctors' language impacts peoples' understanding and decision making about cardiovascular risk
Scientific title
Randomised comparison of the impact of different terminologies and labelling for hypertension on severity perception and willingness to accept treatment
Secondary ID [1] 296284 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
hypertension 309958 0
cardiovascular disease 310056 0
Condition category
Condition code
Public Health 308732 308732 0 0
Other public health
Cardiovascular 308812 308812 0 0
Hypertension

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This experimental study seeks to investigate the effect of different labels for high blood pressure (hypertension vs high normal blood pressure) on treatment decision-making and psychosocial outcomes (perceived severity; level of concern), compared to a control group where no label is given. It will also explore whether any effect is affected by a) sharing absolute risk information and b) health literacy.

The intervention will be delivered via an online survey to each participant which they can complete on any computer at their convenience during the study period. Website analytics will be used to monitor completion rates to monitor adherence to the study.

Each participant will read a hypothetical diagnosis based on the group to which they have been randomised and complete a questionnaire based on this information (anticipated time to complete the survey is approximately 15minutes).

Survey participants will be randomised into one of three groups receiving a different hypothetical diagnosis from a clinician, either the ‘hypertension label’ arm, ‘high normal blood pressure’ arm and a ‘control’ arm given no label. Within each arm of the study they will be randomised to one of two sub groups, receiving either an ‘absolute risk description’ or no further information.

HYPERTENSION LABEL STUDY ARM HYPOTHETICAL
You are at your doctor (GP) for a check-up. The doctor has taken your blood pressure a few times recently and says:
Your blood pressure readings are 135/ 85 and that means you have hypertension.

*Absolute risk description provided to half of the study arm through randomisation:
Hypertension can increase your risk of heart disease. Combining your current blood pressure reading with your other risk factors means your overall risk of a heart attack or stroke in the next 10 years is low (that is, you have less than 10% risk of a heart attack or stroke)

HIGH NORMAL BP LABEL STUDY ARM HYPOTHETICAL:
You are at your doctor (GP) for a check-up. The doctor has taken your blood pressure a few times recently and says:
Your blood pressure readings are 135/ 85 and that means you have high normal blood pressure.

*Absolute risk description provided to half of the study arm through randomisation:
High blood pressure can increase your risk of heart disease. Combining your current blood pressure reading with your other risk factors means your overall risk of a heart attack or stroke in the next 10 years is low (that is, you have less than 10% risk of a heart attack or stroke)
Intervention code [1] 312613 0
Prevention
Comparator / control treatment
Survey participants randomised into the control arm of the study will be shown hypothetical blood pressure reading information with no diagnosis label provided and given either absolute risk information related to this blood pressure reading or no further information.

NO LABEL (ABSOLUTE RISK) CONTROL STUDY ARM HYPOTHETICAL:
You are at your doctor (GP) for a check-up. The doctor has taken your blood pressure a few times recently and says:
Your blood pressure readings are 135/ 85. This blood pressure is close to the average blood pressure for someone your age, but a little higher.

*Absolute risk description provided to half of the study arm through randomisation:
High blood pressure can increase your risk of heart disease. Combining your current blood pressure reading with your other risk factors means your overall risk of a heart attack or stroke in the next 10 years is low (that is, you have less than 10% risk of a heart attack or stroke)

Control group
Active

Outcomes
Primary outcome [1] 307718 0
Willingness to accept treatment (lifestyle)

Questionnaire includes questions specifically designed for this study testing willingness informed using measures previously validated and published in research testing the impact of diagnosis labelling, particularly Copp (2017) and Scherer (2013).

References:
Copp, T., McCaffery, K., Azizi, L., Doust, J., Mol, B., & Jansen, J. (2017). Influence of the disease label 'polycystic ovary syndrome' on intention to have an ultrasound and psychosocial outcomes: A randomised online study in young women. Human Reproduction, 32(4), 876-884.

Scherer, L. D., Zikmund-Fisher, B. J., Fagerlin, A., & Tarini, B. A. (2013). Influence of "GERD" label on parents' decision to medicate infants. Pediatrics, 131(5), 839-845.


Timepoint [1] 307718 0
At time of questionnaire completion
Primary outcome [2] 307719 0
Perception of severity or level of concern.

This is a composite primary outcome. Measures on perceptions of the hypothetical diagnoses have been developed from the Illness Perception Questionnaire and informed by the Positive and Negative Affect Schedule (PANAS)

References for the IPQ and PANAS:
Broadbent, E., Petrie, K. J., Main, J., & Weinman, J. (2006). The brief illness perception questionnaire. Journal of Psychosomatic Research, 60(6), 631-637.

Thompson, E. R. (2007). Development and validation of an internationally reliable short-form of the positive and negative affect schedule (PANAS). Journal of Cross-Cultural Psychology, 38(2), 227-242.
Timepoint [2] 307719 0
At time of questionnaire completion
Primary outcome [3] 307776 0
Willingness to accept treatment (medication)

Questionnaire includes questions specifically designed for this study testing willingness informed using measures previously validated and published in research testing the impact of diagnosis labelling, particularly Copp (2017) and Scherer (2013).

References:
Copp, T., McCaffery, K., Azizi, L., Doust, J., Mol, B., & Jansen, J. (2017). Influence of the disease label 'polycystic ovary syndrome' on intention to have an ultrasound and psychosocial outcomes: A randomised online study in young women. Human Reproduction, 32(4), 876-884.

Scherer, L. D., Zikmund-Fisher, B. J., Fagerlin, A., & Tarini, B. A. (2013). Influence of "GERD" label on parents' decision to medicate infants. Pediatrics, 131(5), 839-845.


Timepoint [3] 307776 0
At time of questionnaire completion
Secondary outcome [1] 352631 0
Does hypertension labelling impact on a person’s plan to manage their health?

Questionnaire includes questions specifically designed for this study testing plans to manage health informed using measures previously validated and published in research testing the impact of diagnosis labelling, particularly Copp (2017) and Scherer (2013).

References:
Copp, T., McCaffery, K., Azizi, L., Doust, J., Mol, B., & Jansen, J. (2017). Influence of the disease label 'polycystic ovary syndrome' on intention to have an ultrasound and psychosocial outcomes: A randomised online study in young women. Human Reproduction, 32(4), 876-884.

Scherer, L. D., Zikmund-Fisher, B. J., Fagerlin, A., & Tarini, B. A. (2013). Influence of "GERD" label on parents' decision to medicate infants. Pediatrics, 131(5), 839-845.
Timepoint [1] 352631 0
At time of questionnaire completion

Eligibility
Key inclusion criteria
People aged 40-50
Minimum age
40 Years
Maximum age
50 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Participant has been diagnosed with, or reports that a close family member has been diagnosed with: heart disease, hypercholesterolaemia, high blood pressure, kidney disease or diabetes

Smokers

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)
Researchers will have no direct contact with participants. Participants will be enrolled into the study via independent recruitment provider Research Now SSI and provided with a link to complete a survey via Qualtrics. Participants will be randomised via the qualtrics software.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Qualtrics computer software will randomly allocate each participant to one of the arms of the trial as they enter the study.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Data will be collected via a survey and deidentified. Survey participants will be randomised into one of three hypothetical groups, either the ‘hypertension label’ arm, ‘high normal blood pressure’ arm and a ‘control’ arm given no label. Within each arm of the study they will be randomised to one of two sub groups, receiving either an ‘absolute risk description’ or no further information. This will allow analysis across four sub groups of the study (214 randomised to each of four groups within the survey of 1284 participants)

Logistic regression will be used to analyse the primary categorical outcome (i.e., more willing to accept medication vs. more willing to make lifestyle changes), and multiple linear regression for primary continuous outcomes (severity and concern), with label (medicalised; lay; no label) and absolute risk (provided; not provided) included as categorical study factors in both models. The use of regression modelling will allow for control of any baseline differences in demographics between randomised groups, if required.
A similar regression modelling approach will be used for the secondary outcomes (logistic models for categorical outcomes; linear models for continuous outcomes). Potential effect modification by health literacy (as NVS) will be examined by inclusion of an interaction term between health literacy and the study factors in relevant models. Similarly, inclusion of an interaction term of the two study factors will be included to determine if the provision of absolute risk information modifies the effect of labelling on the primary outcomes.

Recruitment
Recruitment status
Not yet recruiting
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] 300874 0
University
Name [1] 300874 0
University of Sydney
Address [1] 300874 0
School of Public Health
Edward Ford Building A27
The University of Sydney
NSW
2006
Country [1] 300874 0
Australia
Primary sponsor type
University
Name
School of Public Health, University of Sydney
Address
School of Public Health
Edward Ford Building A27
The University of Sydney
NSW
2006
Country
Australia
Secondary sponsor category [1] 300453 0
None
Name [1] 300453 0
Address [1] 300453 0
Country [1] 300453 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301651 0
University of Sydney Human Research Ethics Committee
Ethics committee address [1] 301651 0
Research Integrity and Ethics Administration | Research Portfolio
THE UNIVERSITY OF SYDNEY
Level 3, Administration Building (F23) | The University of Sydney | NSW | 2006
Ethics committee country [1] 301651 0
Australia
Date submitted for ethics approval [1] 301651 0
17/09/2018
Approval date [1] 301651 0
07/11/2018
Ethics approval number [1] 301651 0
2018/828

Summary
Brief summary
This experimental study seeks to investigate the effect of different labels for high blood pressure (e.g. hypertension vs high normal blood pressure) on treatment decision-making and psychosocial outcomes (perceived severity; level of concern), compared to a control group where no label is given. It will also explore whether any effect is affected by a) sharing absolute risk information and b) health literacy.

Australian adults aged 40-50 with a normal risk of hypertension will be sampled. Only those with an average risk profile will be included in the study, to be presented with a hypothetical diagnosis and asked a number of survey questions investigating health literacy, treatment decision making, risk perception and perceived self-efficacy.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 87662 0
Prof Kirsten McCaffery
Address 87662 0
The University of Sydney
Rm 128B, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 87662 0
Australia
Phone 87662 0
+61 2 9351 7220
Fax 87662 0
Email 87662 0
kirsten.mccaffery@sydney.edu.au
Contact person for public queries
Name 87663 0
Prof Kirsten McCaffery
Address 87663 0
The University of Sydney
Rm 128B, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 87663 0
Australia
Phone 87663 0
+61 2 9351 7220
Fax 87663 0
Email 87663 0
kirsten.mccaffery@sydney.edu.au
Contact person for scientific queries
Name 87664 0
Prof Kirsten McCaffery
Address 87664 0
The University of Sydney
Rm 128B, Edward Ford Building A27
The University of Sydney
NSW 2006
Country 87664 0
Australia
Phone 87664 0
+61 2 9351 7220
Fax 87664 0
Email 87664 0
kirsten.mccaffery@sydney.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
only de-identified data will be available
What supporting documents are/will be available?
Ethical approval
Attachments/websites
Type [1] 374 0
Ethical approval
URL/details/comments [1] 374 0
Attachment [1] 374 0
Summary results
Not applicable