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Trial registered on ANZCTR


Registration number
ACTRN12622001570774
Ethics application status
Approved
Date submitted
23/11/2022
Date registered
20/12/2022
Date last updated
1/12/2023
Date data sharing statement initially provided
20/12/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
What are the effects of an open-label placebo?
Scientific title
Examining side effects in healthy adults who have been administered an open-label placebo.
Secondary ID [1] 308366 0
None
Universal Trial Number (UTN)
U1111-1284-6508
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
General health 328156 0
Nocebo effect 328520 0
Condition category
Condition code
Mental Health 325213 325213 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
There will be one 45-minute face-to-face session for the participants with the researcher. After completing the baseline questionnaire, all participants will receive a standardised explanation verbally about open-label placebos by the researcher. They will be informed about the effects a placebo might have and that they can either improve health outcomes or induce side effects. Participants will then be randomised into the experimental or control group.

Participants in the experimental group will be asked to take a placebo pill consisting of microcrystalline cellulose. The researcher will supervise participants taking the placebo.

In both conditions, participants will be asked to fill out two follow-up questionnaires, one 15 minutes after the intervention and the other one 24 hours after the intervention.
Intervention code [1] 324815 0
Early detection / Screening
Comparator / control treatment
The control group receives the same instructions about open-label placebos as participants in the experimental group. After the instructions, participants in the control group will be asked to wait for 15 minutes without taking an open-label placebo.
Control group
Active

Outcomes
Primary outcome [1] 333050 0
Participants´ reporting of side effects measured with the Side Effect Attribution Scale (SEAS).
Timepoint [1] 333050 0
15 minutes and 24 hours post-intervention
Secondary outcome [1] 415632 0
Mood measured with the Positive and Negative Affect Schedule (PANAS) (Watson, Clark & Tellegen, 1988).
Timepoint [1] 415632 0
15 minutes and 24 hours post-intervention

Eligibility
Key inclusion criteria
Participants are eligible to take part in this study if they are aged 18 years or older, able to fill out the questionnaires, willing to participate and fluent in the English language.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
None.

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)
Sealed opaque envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e., computerised sequence generation).
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/02/2023
Actual
22/02/2023
Date of last participant enrolment
Anticipated
13/03/2023
Actual
15/03/2023
Date of last data collection
Anticipated
14/03/2023
Actual
15/03/2023
Sample size
Target
60
Accrual to date
Final
60
Recruitment outside Australia
Country [1] 25107 0
New Zealand
State/province [1] 25107 0
Auckland

Funding & Sponsors
Funding source category [1] 312606 0
University
Name [1] 312606 0
The University of Auckland
Country [1] 312606 0
New Zealand
Primary sponsor type
University
Name
The University of Auckland
Address
85 Park Road, Grafton, Auckland, New Zealand, 1023
Country
New Zealand
Secondary sponsor category [1] 314224 0
None
Name [1] 314224 0
Address [1] 314224 0
Country [1] 314224 0
Other collaborator category [1] 282479 0
Individual
Name [1] 282479 0
Professor Keith Petrie
Address [1] 282479 0
The University of Auckland
M&HS Bldg 507
Level 3, Room 320
85 Park Road
Grafton
Auckland, 1023
Country [1] 282479 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311931 0
Auckland Health Research Ethics Committee
Ethics committee address [1] 311931 0
24 Symonds Street, Auckland, New Zealand, 1010
Ethics committee country [1] 311931 0
New Zealand
Date submitted for ethics approval [1] 311931 0
24/10/2022
Approval date [1] 311931 0
17/11/2022
Ethics approval number [1] 311931 0

Summary
Brief summary
This study aims to determine whether participants report side effects after receiving an open-label placebo and whether side effects are attributed to the open-label placebo. It also determines which demographic and psychological characteristics are associated with the reporting of side effects.

It is hypothesized that participants who receive an open-label placebo will report more side effects and decreased mood, compared to those who do not receive an open-label placebo. It is expected that these effects will remain at both 15 minutes and 24 hours follow-up. It is also hypothesized that demographic (i.e., female gender) and psychological characteristics at baseline (i.e., higher anxiety, perceived sensitivity to medicines and modern health worries) will be associated with increased reporting of side effects after taking an open-label placebo.

This study will contribute to existing literature on open-label placebos by investigating their impact on side effects. Findings may also help to identify which patients are more vulnerable to developing nocebo responses to future treatments.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 122882 0
Prof Keith Petrie
Address 122882 0
The University of Auckland
M&HS Building 507
Level 3, Room 320
85 Park Road, Grafton
Auckland 1023
Country 122882 0
New Zealand
Phone 122882 0
+649 923 6564
Fax 122882 0
Email 122882 0
[email protected]
Contact person for public queries
Name 122883 0
Keith Petrie
Address 122883 0
The University of Auckland
M&HS Building 507
Level 3, Room 320
85 Park Road, Grafton
Auckland 1023
Country 122883 0
New Zealand
Phone 122883 0
+649 923 6564
Fax 122883 0
Email 122883 0
[email protected]
Contact person for scientific queries
Name 122884 0
Keith Petrie
Address 122884 0
The University of Auckland
M&HS Building 507
Level 3, Room 320
85 Park Road, Grafton
Auckland 1023
Country 122884 0
New Zealand
Phone 122884 0
+649 923 6564
Fax 122884 0
Email 122884 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
We do not intend to share any identifiable data. Only the research team will have access to this information.


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
No additional documents have been identified.