title: A randomised controlled trial of the effects of a web-based PSA decision aid, Prosdex. Protocol.
abstract: BACKGROUND
  Informed decision making is the theoretical basis in the UK for men's decisions about Prostate Specific Antigen (PSA) testing for prostate cancer testing. The aim of this study is to evaluate the effect of a web-based PSA decision-aid, Prosdex, on informed decision making in men. The objective is to assess the effect of Prosdex on six specific outcomes: (i) knowledge of PSA and prostate cancer-related issues - the principal outcome of the study; (ii) attitudes to testing; (iii) decision conflict; (iv) anxiety; (v) intention to undergo PSA testing; (vi) uptake of PSA testing. In addition, a mathematical simulation model of the effects of Prosdex will be developed.
  
  
  METHODS
  A randomised controlled trial with four groups: two intervention groups, one viewing Prosdex and the other receiving a paper version of the site; two control groups, the second controlling for the potential Hawthorn effect of the questionnaire used with the first control group. Men between the ages of 50 and 75, who have not previously had a PSA test, will be recruited from General Practitioners (GPs) in Wales, UK. The principal outcome, knowledge, and four other outcome measures - attitudes to testing, decision conflict, anxiety and intention to undergo testing - will be measured with an online questionnaire, used by men in three of the study groups. Six months later, PSA test uptake will be ascertained from GP records; the online questionnaire will then be repeated. These outcomes, and particularly PSA test uptake, will be used to develop a mathematical simulation model, specifically to consider the impact on health service resources.
authors.affiliation: Department of Primary Care and Public Health, Cardiff University, Wales, UK. evansr10@cardiff.ac.uk
authors.forename: Rhodri
authors.initials: R
authors.lastname: Evans
authors.forename: Glyn
authors.initials: G
authors.lastname: Elwyn
authors.forename: Adrian
authors.initials: A
authors.lastname: Edwards
authors.forename: Robert
authors.initials: R
authors.lastname: Newcombe
authors.forename: Paul
authors.initials: P
authors.lastname: Kinnersley
authors.forename: Pat
authors.initials: P
authors.lastname: Wright
authors.forename: Jeff
authors.initials: J
authors.lastname: Griffiths
authors.forename: Joan
authors.initials: J
authors.lastname: Austoker
authors.forename: Richard
authors.initials: R
authors.lastname: Grol
mesh_terms: D000368:Aged; D001294:Attitude to Health; D002985:Clinical Protocols; D003657:Decision Making; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D011795:Surveys and Questionnaires; D006113:United Kingdom
chemical_list: D017430:Prostate-Specific Antigen