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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Determining the effectiveness of different forms of interpretation bias training on pain outcomes in healthy university students.
Scientific title
Determining the effectiveness of different forms of interpretation bias training on pain outcomes in healthy university students.
Secondary ID [1] 286621 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pain 294941 0
Condition category
Condition code
Musculoskeletal 295198 295198 0 0
Other muscular and skeletal disorders

Study type
Description of intervention(s) / exposure
Brief interpretation bias training will be delivered in a laboratory setting. There will be 4 versions of this training. Undergraduate students will be taught to classify ambiguous facial
expressions as either pain related or as benign; or will be taught to resolve ambiguous written scenarios as either pain related or benign. As such, participants will complete only one of the following 4 training procedures: 1) training towards pain faces, 2) training away from pain faces, 3) training towards pain interpretations of scenarios, or 4) training away from pain interpretations of scenarios. This intervention will be conducted in a single session and will last approximately 15 minutes.
The scenario based training procedure is called the 'ambiguous situations paradigm' and has been previously developed and validated by Jones and Sharpe (2014). Participants will be presented with an ambiguous sentence or paragraph, which can be interpreted as pain related or benign until the last word. The last word will have letters missing, but can only be resolved by the participant in one way, to create a pain/threatening scenario (group trained towards pain interpretation) or a neutral scenario (group trained towards a benign interpretation). These scenarios are followed by a question that will consolidate the resolution of the paragraph.
The face based training procedure is currently being developed but is based on the 'incidental learning task' as described by Khatibi, Schrooten, Vancleef, & Vlaeyen (2014). Participants will be presented with pictures of happy faces and pain faces, which will be followed by a target consistently on the left or the right hand side of the screen depending on the type of facial expression. Participants need to respond to this target with a mouse button press. Ambiguous faces will then be presented, and will be followed either by a target consistently on the pain face side (group trained towards pain interpretation) or happy face side (group trained towards a benign interpretation).

All other questionnaires, computer tasks and the pain procedure will be used for assessment purposes only, and are detailed as follows:

Participants will complete demographic questions as well as validated questionnaires including the Fear of Pain Questionniare (McNeil & Rainwater, 1998), Depression Anxiety Stress Scale (Lovibond & Lovibond, 1996), and the Pain Catastrophising Scale (Sullivan, Bishop, & Pivik, 1995). These will be completed on a computer.

Participants will also 3 computer tasks to measure interpretation biases following the manipulation. These include the incidental learning task (Khatibi, Schrooten, Vancleef, & Vlaeyen, 2014) and the word recognition task as developed by Jones and Sharpe (2014). A third measurement task will be used that is currently being developed by the research group, which will be based on the stimuli presented in the incidental learning task.

Participants will complete an experimental pain task.
Two water tanks manufactured by Thermoline Scientific Australia are used to conduct the cold pressor task. Each tank is comprised of a 20L circulating water bath chamber (model TLWB-30), immersion cooler (TIC-400) and a heat circulator (TU-3). In order to ensure participants initial arm temperature is controlled for, they are firstly asked to submerge
their arm up to the elbow for 30 seconds in the warm tank, with a maintained temperature of 37degrees C (plus or minus 0.5). Following this, they submerged the same arm up to the elbow into the tank of cold water, maintained at 5 degrees C(plus or minus 0.5). Research in the past indicates the cold pressor task produces the “Lewis Effect”, whereby pain is produced by vasodilation of the blood vessels due to
warm water, quickly followed by vasoconstriction due to cold water.

The whole experiment will take up to one hour to complete. The study will be administered by a qualified psychologist, as Jemma Todd is a qualified psychologist and Professor Louise Sharpe is a qualified Clinical Psychologist. A research script will be developed so that participation is as similar as possible across participants.
Intervention code [1] 291757 0
Other interventions
Comparator / control treatment
Training classification of ambiguous information as benign (i.e. not pain related).
All participants, including those in the control group, will complete the measurement tasks described in intervention/exposure. That is, they will also complete the questionnaires, the 3 interpretation bias measures, and the cold pressor task.
Control group

Primary outcome [1] 294950 0
Pain: Average pain ratings (on a visual analogue scale; VAS) observed in response to the cold pressor task
Timepoint [1] 294950 0
During the cold pressor task
Primary outcome [2] 294951 0
Hesitance: The time taken to emerge arm fully in the cold pressor task (we measure time using a stopwatch)
Timepoint [2] 294951 0
During the cold pressor task
Primary outcome [3] 294952 0
Tolerance: time that arm is left in the cold pressor task (max 4 minutes) (We use a stopwatch to measure time)
Timepoint [3] 294952 0
During the cold pressor task
Secondary outcome [1] 314451 0
Threshold: Time taken for the participant to report experiencing pain during the cold pressor task (We use a stopwatch)
Timepoint [1] 314451 0
During the cold pressor task
Secondary outcome [2] 314452 0
Pain-related distress: Ratings (0-10) of Subjective Units of Distress
associated with pain, rated following task
Timepoint [2] 314452 0
During the cold pressor task
Secondary outcome [3] 314453 0
Interpretation bias
Timepoint [3] 314453 0
Measured during the interpretation bias Measurement tasks, following the interpretation bias training
Interpretation bias will be assessed using three measurement tasks:
1) The incidental learning task (Khatibi et al., 2014): In this task, participants are presented with happy and pain faces, and are trained to respond to a target that is consistently presented on the right or left depending on facial expression. Participants are then presented with ambiguous faces, with the target appearing 50% of the time on both sides. In this way, reaction times to ambiguous cues occurring on the pain and happy sides can be compared, with faster reactions to pain congruent targets and slower reactions to happy congruent targets indicating a bias towards pain interpretations.
2) the word recognition task (Jones & Sharpe, 2014): Participants are presented with ambiguous scenarios, which can be resolved by completing the final word of the paragraph. There are two ways to resolve the ambiguity, with a pain word or a benign word. Pain interpretation biases will be measured by the number and proportion of scenarios that are resolved with pain words in comparison to neutral words.
3) the face morphing task. This is currently being developed by the research group, and will be piloted by another researcher prior to being used in this experiment. A picture of a happy face will be presented, that will slowly morph into a pain face. Participants are required to indicate when the face becomes a pain face. Similarly, a picture of a pain face will be presented, that will slowly morph into a happy face. Participants indicate when the pain face stops being a pain face. Faster reaction times to the happy --> pain morph and slower reactions to the pain --> happy morph will indicate a bias towards pain interpretations.

Key inclusion criteria
Undergraduate psychology students
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Cardiac problems
Current or recent chronic pain
Current pain on a visual analogue scale of >3/10
Consumed excessive alcohol or caffeine in 24 hrs prior to study
Used analgesic medications on morning of study
Insufficient written and spoken English
Have previously completed the cold pressor task in another experiment

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will first be randomly allocated to the type of interpretation training task (i.e. either word or face based training). This will be achieved through use of a set of randomly generated numbers from computer software that will allocate participants in to two groups. These group allocations will be blacked out on a computer screen. Once the participant has consented to take part, their allocation will be revealed to the experimenter.
Secondly, allocation to the direction of training (i.e. towards pain or benign interpretations) will be blinded to the experimenter, as the randomisation of allocation to direction will be built in to each computer task.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
For allocation to type of experimental task:
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis
2x2 between subjects AN(C)OVA
Bivariate correlational analyses

Sample size calculations:
Based on Jones and Sharpe (2014) 104 participants are required to elicit a moderate effect size (26x4 conditions).
An a-priori power analysis based on the ANOVA (2) x 2 calculations indicated, 98 participants in total would be sufficient to detect medium effects at 80% power and p<.05.
Therefore, a sample size of 120 was chosen to allow for participants who withdraw, drop out, or incorrectly sign up to the study who do not meet the inclusion criteria.

Recruitment status
Reason for early stopping/withdrawal
Lack of funding/staff/facilities
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 9620 0
2006 - The University Of Sydney

Funding & Sponsors
Funding source category [1] 291190 0
Self funded/Unfunded
Name [1] 291190 0
Address [1] 291190 0
Country [1] 291190 0
Primary sponsor type
The University of Sydney
The University of Sydney
NSW 2006
Secondary sponsor category [1] 289870 0
Name [1] 289870 0
Address [1] 289870 0
Country [1] 289870 0

Ethics approval
Ethics application status
Ethics committee name [1] 292762 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 292762 0
Level 2, Margaret Telfer
The University of Sydney
Sydney NSW
Ethics committee country [1] 292762 0
Date submitted for ethics approval [1] 292762 0
Approval date [1] 292762 0
Ethics approval number [1] 292762 0

Brief summary
This study aims to explore the effect of pain-related interpretation bias training on interpretation biases to pain and the experience of acute pain. Participants will complete one of 4 types of interpretation bias training, and will also complete questionnaires, 3 computer based interpretation bias measurement tasks and an experimental pain task.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 56894 0
Prof Louise Sharpe
Address 56894 0
Brennan MacCallum Building, School of Psychology, The University of Sydney, NSW, 2006
Country 56894 0
Phone 56894 0
+61 2 93514558
Fax 56894 0
Email 56894 0
Contact person for public queries
Name 56895 0
Ms Jemma Todd
Address 56895 0
Transient Building, School of Psychology, The University of Sydney, NSW, 2006
Country 56895 0
Phone 56895 0
+61 2 93512560
Fax 56895 0
Email 56895 0
Contact person for scientific queries
Name 56896 0
Prof Louise Sharpe
Address 56896 0
Brennan MacCallum Building, School of Psychology, The University of Sydney NSW 2006
Country 56896 0
Phone 56896 0
+61 2 93514558
Fax 56896 0
Email 56896 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Study withdrawn prior to commencing
What supporting documents are/will be available?
No other documents available
Summary results
No Results