Informed decision making and prostate specific antigen (PSA) testing for prostate cancer: a randomised controlled trial exploring the impact of a brief patient decision aid on men's knowledge, attitudes and intention to be tested.

OBJECTIVE: To examine the impact of a brief patient decision aid (pDA) on men's knowledge, attitudes and intention to have a prostate specific antigen (PSA) test. To explore the important predictors of intention to be tested in men who received the brief pDA. METHODS: A brief pDA designed to facilitate informed decision-making for men considering PSA testing was developed for the NHS Prostate Cancer Risk Management Programme. Men aged 40-75 years selected from 11 General Practices in England and Wales were randomised to receive either a mailed copy of the brief pDA and a questionnaire (intervention group), or a questionnaire alone (control group). The questionnaire assessed knowledge, attitudes, perceived risk and intention to have a PSA test and, for the intervention group, their perceptions of the brief pDA. RESULTS: Nine hundred and ninety of the men who were eligible for the study returned completed questionnaires (response rate=54%). Men who received the brief pDA had significantly higher knowledge scores (p<0.0001) and less positive attitudes (p<0.0001) regarding PSA testing than men in the control group. There was no significant difference between the two groups in intention to be tested within the next 12 months. 87% of men found the brief pDA was easy to read, 94% considered it contained about the right amount of detail and 94% felt the information was presented in a balanced way. Multivariate analysis identified perceived risk (p<0.0001), perceived benefits of PSA testing (p