A randomised controlled trial of the effects of a web based Prostate Specific Antigen decision explorer, Prosdex

ISRCTN ISRCTN48473735
DOI https://doi.org/10.1186/ISRCTN48473735
Protocol serial number RCUC062 C6475/A7490
Sponsor Cardiff University (UK)
Funder Cancer Research UK (UK) (ref: C6475)
Submission date
21/03/2007
Registration date
26/04/2007
Last edited
15/12/2011
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Cancer
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Glyn Elwyn
Scientific

Department of Primary Care and Public Health
Centre for Health Sciences Research
Cardiff University
2nd Floor, Neuadd Meirionnydd
Heath Park
Cardiff
CF14 4YS
United Kingdom

elwyng@cardiff.ac.uk

Study information

Primary study designInterventional
Study designRandomised controlled trial
Secondary study designRandomised controlled trial
Scientific title
Study acronymPROSDEX
Study objectivesTo evaluate the effects on men of a web-based Prostate Specific Antigen (PSA) decision-aid, Prosdex. The objectives are to assess the effect of Prosdex on:
1. Knowledge of PSA and prostate cancer-related issues
2. Attitudes to testing
3. Decision conflict
4. Anxiety
5. Intention to undergo PSA testing
6. Uptake of PSA testing

In addition, a mathematical simulation model of the effects of Prosdex on subsequent resource use and health outcomes will be developed. The null hypothesis, based on the principal outcome, knowledge, is that Prosdex would not have an effect on knowledge of PSA and prostate cancer-related issues.
Ethics approval(s)Approval received from the South East Wales Research Ethics Committee, Panel D on the 8th January 2007 (ref: 06/WSE04/138).
Health condition(s) or problem(s) studiedPSA decision aids, prostate cancer
InterventionA web-based PSA decision aid, Prosdex: it will require a password for access and will generate the online questionnaire.

Intervention group:
Group one: Men in intervention group one will be asked to log onto and view the website, either in their own homes or in another setting of their choice.
Group two: The second intervention group will receive a paper document comprising the text of the website. This enables evaluation of the Prosdex features (e.g. video clips and the structured decision support) that go beyond the mere presentation of the text content.

Control group:
Group three: In the first control group, men, after inserting their password, will be asked to complete the online questionnaire without viewing Prosdex.
Group four: The second control group will not initially be given the details of the study website.
Intervention typeOther
Primary outcome measure(s)

Knowledge of PSA and prostate cancer-related issues: this will be assessed using a set of knowledge questions, used in an earlier evaluation of a brief paper-based leaflet about PSA testing, which showed an ability to discriminate between intervention and control groups.

The primary outcome, knowledge, will be measured immediately after the intervention: that is, men will be directed, automatically, from the Prosdex website to the online questionnaire. Men in the second intervention group and the first control group will also be asked at T0 to log onto the online questionnaire.

Key secondary outcome measure(s)

The secondary outcome measures will be measured immediately after the intervention: that is, men will be directed, automatically, from the Prosdex website to the online questionnaire.

1. Attitudes to testing: this will use a 12-item scale developed and used in the same evaluation of a brief paper-based leaflet about PSA testing
2. Decision conflict: this scale measures patients’ confidence or uncertainty (‘conflict’) about whether they feel their choice is the best for them personally. It has acceptable validity and reliability (internal consistency alpha coefficients range from 0.78 - 0.89; test-retest reliability coefficients exceed 0.80). Given the nature of the decision about having a PSA test, with a high degree of uncertainty likely to affect decision making, it is important to use this, the most widely used outcome measure in decision aid studies
3. Anxiety: This will be assessed using the short form Spielberger questionnaire for ‘state’ anxiety, validated and shown to be responsive in our earlier studies of shared decision making and risk communication
4. Intention to undergo PSA testing: this will be assessed using a single item question, with Likert-like response scale, which has also been used in our earlier evaluation of a brief paper-based leaflet about PSA testing
5. Uptake of the PSA test: measured six months after the intervention

In addition, based on these results, a mathematical simulation model of the effects of Prosdex on subsequent resource use and health outcomes will also be developed. Secondary outcomes one to four, in addition to the primary outcome, knowledge, will be gathered from the online questionnaire.

After the six month PSA testing, all the men will be asked to to complete the online questionnaire again.

Completion date01/06/2008

Eligibility

Participant type(s)Patient
Age groupAdult
SexMale
Target sample size at registration600
Key inclusion criteriaMen between ages of 50 and 75
Key exclusion criteria1. Previous PSA test or prostate cancer
2. Inability to access internet
3. Men who are known to be unable to read English
4. Serious uncontrolled medical conditions or concurrent medical illness likely to compromise life expectancy
5. Severe mental illness or dementia
Date of first enrolment01/10/2007
Date of final enrolment01/06/2008

Locations

Countries of recruitment

  • United Kingdom
  • Wales

Study participating centre

Department of Primary Care and Public Health
Cardiff
CF14 4YS
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to shareNo
IPD sharing plan summary
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 1. results 26/05/2010 Yes No
Results article results 06/08/2010 Yes No
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