Methods: We conducted a randomized trial using a crossed 2x2 factorial design. Participants (N=105) were assigned to either view a traditional didactic decision aid providing comprehensive information about PSA screening (Factor 1), a decision aid using a chronic illness trajectory model for prostate cancer followed by a one item time trade off exercise (Factor 2), both the didactic decision and the chronic illness trajectory aids, or assigned to review prostate cancer specific websites (CDC & ACS). Participants completed a study questionnaire before randomization and after reviewing intervention materials, including a validated PSA Knowledge questionnaire (Range 0-10).

Results: The median age was 58 years. The majority of men were married (75%), Caucasian (88%) and college-educated (66%). Participants in all four groups were equally likely to review the PSA information provided (95% accessed information). Post-intervention PSA Knowledge scores for participants randomized to the didactic decision aid (n=27), chronic illness trajectory aid (n=31), combination aid (n=25) and Internet link sites (n=22) were 8.7 (95% CI 8.2 to 9.2), 8.4 (7.7 to 9.0), 8.2 (7.4 to 9.0) and 7.0 (5.8 to 8.2), respectively (F = 3.3, p<0.05). Men randomized to any of the three decision aids (compared to the Internet link group) were significantly more likely to know that a biopsy is recommended after an abnormal PSA (p<0.05), that a biopsy is a better test for diagnosing cancer than a PSA (p<0.01), and that loss of sexual function is a common side effect of prostate cancer treatment (p<0.01).

Conclusion: Men randomized to decision aids designed specifically to inform about PSA screening, prostate cancer and treatment outcomes had better knowledge about prostate cancer than men randomized to review publicly available, reputable prostate cancer websites. Patients who rely on the internet as their primary source of information may not be fully aware of the risks and benefits of prostate cancer screening. Therefore, commonly used websites should be formally tested to ensure that viewers have an understanding of important disease specific issues. Web sites designed to enhance shared decision making may lead to different choices than reputable sites that simply summarize recommendations.