Decision aids increased knowledge about prostate cancer but didn't affect screening rates

Decision aids improved participants' informed decision making about prostate cancer screening but did not change the actual screening rates, a study found.

Patients were randomly assigned to groups receiving print-based decision aids (n=628), Web-based interactive decision aids (n=625) or usual care (n=626) and were then assessed at baseline, one month and 13 months for prostate cancer knowledge, decisional conflict, decisional satisfaction and whether they underwent screening.

Decision aid materials included six sections: introductory material, screening tests and possible results, treatment options and risks, prostate cancer risk factors and encouragement to discuss screening with a physician, a 10-item values clarification tool, and resources for more information. The Web-based materials added interactive tools and displays. Results were published online July 29 by JAMA Internal Medicine.

Print and Web interventions resulted in greater knowledge (assessed by an 18-item true/false scale of knowledge of testing, screening controversy, risk factors, treatment benefits and limitations and natural history of disease) than usual care. At one month, the adjusted mean difference between the Web education trial arm and usual care was estimated as a β-coefficient of 2.26 (95% CI, 1.88 to 2.64; P<0.001). The difference for print compared to usual care was a β-coefficient of 2.40 (95% CI, 2.02 to 2.78; P<0.001).

At 13 months, the effect was a β-coefficient of 1.46 (95% CI, 1.07 to 1.84; P<0.001) for Web education versus usual care and a β-coefficient of 1.54 (95% CI, 1.17 to 1.91; P<0.001) for print versus usual care. There was no difference in effect between Web and print materials at one or 13 months.

Both the Web and print decision aids led to reduced decisional conflict. At 13 months, the effect was still significant but was smaller than at one month. Again, there was no difference between Web and print materials at one or 13 months.

Participants in the print arm were more likely to report high decisional satisfaction than those in usual care at one and 13 months. Participants in the Web arm also reported greater decisional satisfaction than those in the usual care arm at one month but not at 13 months. Finally, print participants reported significantly greater satisfaction than Web participants at one month but not at 13 months.

Despite all the noted differences in knowledge, decisional conflict and decisional satisfaction, there was no significant difference in the eventual screening rates between the baseline assessment and the 13-month assessment and no significant differences among the print, Web and usual care arms.

“Given the demonstrated beneficial effects of these [decision aids], work is now needed to understand how to deliver them to patients in a systematic manner,” the researchers wrote. “Possible avenues include personal health records, distribution in health care provider offices, or via the websites of large health care organizations. The ongoing questions concerning the impact of [prostate cancer] screening on disease-related mortality and on men's long-term quality of life highlight the need for promoting widespread informed decision making among patients and their physicians.”

An accompanying editorial stated that because screening rates weren't affected by the decisional aids, a future challenge may involve communicating with men who may have already decided about screening on the basis of limited information. “The fact that screening rates were highly stable and unaffected by the intervention may imply that patients, physicians, and clinical systems often operate in stable patterns with respect to screening,” the editorial stated.