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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Designing physical activity interventions based on user’s need for cognition: impact on attention and persuasion among healthy adults
Scientific title
Designing physical activity interventions based on user’s need for cognition: impact on attention and persuasion among healthy adults
Secondary ID [1] 289035 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
physical inactivity 298450 0
Condition category
Condition code
Public Health 298551 298551 0 0
Health promotion/education

Study type
Description of intervention(s) / exposure
Arm 1 - Physical activity module designed to persuade via central route information processing (i.e., deep and critical thinking):

The module in this condition consists of 12 slides., Participants are asked to sit in front of the computer in the laboratory and view the slides in their own time . Participants can only view the slides once and can not view a previous slide once they click 'next', Topics covered include the benefits of physical activity, the physical activity guidelines for Australian adults (published by the Department of health and ageing) and how to get started and stay committed to physical activity. The slide content was developed by the lead researcher, drawing from content developed for previous intervention research (e.g.,

The materials in this condition emphasise facts relating to physical activity and physical activity behaviour change. Strong arguments are presented in a clear and direct manner. No weak arguments are presented and emotional appeals are not used (including humour and emotive language).
Intervention code [1] 294516 0
Comparator / control treatment
Arm 2 - Physical activity module designed to persuade via peripheral route information processing (i.e., feelings, heuristics):

The module in this condition consists of 16 slides, Participants are asked to sit in front of the computer in the laboratory and view the slides in their own time . Topics covered include the benefits of physical activity, what physical activity is recommended and how to get started and stay committed to physical activity.

In contrast to arm 1, the materials in this condition utilize positive images (e.g., sunsets, fun physical activity) and narratives to convey key messages and to increase associations between physical activity and positive feelings. Text is used to create a narrative that people can identify with, rather than to emphasise facts.
Control group

Primary outcome [1] 298034 0
Average gaze duration per slide assessed using eye tracking device and software.
Timepoint [1] 298034 0
Continuous monitoring from start of first slide to the final slide.
Secondary outcome [1] 322980 0
Physical Activity intentions

The following 3-items (Courneya et al., 1999; Courneya, 1994; Rhodes & Courneya, 2003) will be used to assessed physical activity intentions:

1) In the next week, my goal is to be physically active (response option 1- not at all to 7 every day)
2)Over the next week, I intend to engage in physical activity __ times per week (open response option)
3)I intent to engage in physical activity at least every other day over the next week ( (response option 1- not at all to 7 every day)

Responses are summed together to form overall intention score, with higher scores equating to higher intentions.
Timepoint [1] 322980 0
Immediate post-intervention
Secondary outcome [2] 322981 0
Perceived message effectiveness
A 3-item perceived effectiveness scale, adapted from Fishbein et al (2002) and Jensen (2012) will be used to assess the perceived persuasiveness of the messages. The three items are “were the materials convincing”, “would people your age who are not already active be more likely to become active after viewing the materials?” and “Would the materials be helpful for convincing your friends and family to become more physically active?” with 4-point response options: definitely no, no, yes, and definitely yes.
Timepoint [2] 322981 0
Immediate post-intervention
Secondary outcome [3] 323054 0
Need for cognition will be assessed so that it can be examined as an effect modifier

The 18-Item Need for Cognition Scale developed by Cacioppo, Feng Kao and Petty (1984) will be utilised. It is based on the original work by Cacioppo and Petty (1982) and is a shortened form scale of the original 34-item scale and was deemed to be more efficient than the 34-item scale. Item examples include ‘I would prefer complex to simple problems’ and ‘thinking is not my idea of fun’
Timepoint [3] 323054 0

Key inclusion criteria
English proficient adults between the ages of 18-60, who can read and write in English, who can attend the University of Adelaide testing site during business hours (9am-5pm Monday-Friday), who can clearly view a computer screen without the assistance of glasses (contact lenses permitted), who are not already participating in recommended physical activity levels (i.e., 30 minutes of moderate-vigorous physical activity on five or more days per week) and who had not had laser eye surgery are eligible to participate.
Minimum age
18 Years
Maximum age
60 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
laser eye surgery

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)
Individuals interested in participating are asked to complete a screening questionnaire online. All individuals are assigned a unique identification number, Algorithms are used to determine if individuals are eligible. If eligible they are denoted as such in the database. The file is then downloaded from the website and uploaded into R. The allocation script that was developed a priori is then run for eligible individuals only to randomise them into study groups on a ratio of 1:1 using random block sizes. This is carried out by a statistician with de-identified data. The statistician then provides the research team with the allocation sequence.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A random number generator is used.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Linear regression examining interaction between group allocation, need for cognition and outcomes of interest (gaze duration, intentions, message effectiveness).

Assuming that high (low) NFC individuals have 5 min (3 min) attention spans when matched with website (ie central vs peripheral) and 1 min (1 min) spans when mis-matched, and assuming normally distributed attention spans with a common standard deviation of 2 min, then simulations indicate that with 50 individuals (25 in each group) there is at least 80% power to detect an interaction between NFC (high v low) and treatment (central v peripheral) when the prevalence of high NFC is between 30% and 70% of the randomized population.

Recruitment status
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)

Funding & Sponsors
Funding source category [1] 293402 0
Name [1] 293402 0
University of Adelaide
Address [1] 293402 0
North Terrace, University of Adelaide
Adelaide, SA, 5000.
Country [1] 293402 0
Primary sponsor type
University of Adelaide
North Terrace, University of Adelaide
Adelaide, SA. 5000
Secondary sponsor category [1] 292231 0
Name [1] 292231 0
Address [1] 292231 0
Country [1] 292231 0

Ethics approval
Ethics application status
Ethics committee name [1] 294853 0
School of Psychology HREC sub-committee, University of Adelaide
Ethics committee address [1] 294853 0
North Terrace, University of Adelaide
SA, 5000
Ethics committee country [1] 294853 0
Date submitted for ethics approval [1] 294853 0
Approval date [1] 294853 0
Ethics approval number [1] 294853 0

Brief summary
Providing individuals with physical activity advice and guidance can help to improve their physical activity behavior. This is especially the case when individuals are motivated to read the information and are able to understand it and consider it thoughtfully. There is some evidence that providing people with information that is matched to their cognitive processing style, known as need for cognition, increases motivation and ability to read the messages presented. Further, there is evidence that this in turn is associated with greater improvements in attitudes and behaviors. This has been shown in a health context before (e.g., mammogram utilization), but evidence in the physical activity field is lacking. Given that interventions matched to participant’s need for cognition are more resource intensive to develop than unmatched interventions (requiring at least double the intervention materials), research examining the impact of matching to need for cognition in the physical activity domain is needed before this technique is adopted en masse in this area.

We aim to examine how stimuli optimized for central route (deep thinking) processing compared to peripheral route processing (use of simple cues) are processed by individuals with higher and lower need for cognition and the impact of this on the persuasiveness of the materials. This will be achieved in a mixed method laboratory-based study, with outcomes assessed using eye-trackers, combined with brief questionnaires and qualitative interview.

We hypothesize that individuals who are shown materials that best match their cognitive processing style will show greater attention to the materials and less distraction when processing them (assessed by eye tracking devices) compared to individuals who are shown materials that do not match their cognitive processing style. Further, we anticipate that greater attention will be associated with more positive ratings of the intervention materials and greater motivation for physical activity participation (assessed via self-report; quantitative and qualitative methods).

Overall, this study will provide valuable insights into how to develop physical activity messages and in doing so may help to inform the development of more effective physical activity interventions in the future.
Trial website
Trial related presentations / publications
Short CE, Dry M, Skuse A, Quester P, Vincent A, Rebar A, Vandelanotte C, Duncan MJ, Crutzen R. Exploring the interplay between message format, personal relevance and need for cognition on physical activity message processing. Oral presentation. 31st Conference of the European Health Psychology Society: Innovative Ideas in Health Psychology, Padova, Italy. 29th August-02 September, 2017.

Short CE. Access is Not Usage and Usage is Not Engagement per se! Building a science of user engagement to enhance the efficacy of e&mHealth behavior change interventions. ECR Keynote. ISBNPA 2016 annual meeting, Cape Town, South Africa, from June 8-12, 2016.
Public notes

Principal investigator
Name 65246 0
Dr Camille Short
Address 65246 0
Level 7, South Australia Health Medical Research Institute, North terrace,
Adelaide, SA, 5000
Country 65246 0
Phone 65246 0
+61, 8, 83130532
Fax 65246 0
Email 65246 0
Contact person for public queries
Name 65247 0
Dr Camille Short
Address 65247 0
Level 7, South Australia Health Medical Research Institute, North terrace,
Adelaide, SA, 5000
Country 65247 0
Phone 65247 0
+61, 8, 83130532
Fax 65247 0
Email 65247 0
Contact person for scientific queries
Name 65248 0
Dr Camille Short
Address 65248 0
Level 7, South Australia Health Medical Research Institute, North terrace,
Adelaide, SA, 5000
Country 65248 0
Phone 65248 0
+61, 8, 83130532
Fax 65248 0
Email 65248 0

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