Both a printed and a web-based interactive "decision aid" for prostate cancer screening improved men’s understanding of the risks and benefits of screening, compared with usual care, according to a report published online July 29 in JAMA Internal Medicine.
However, neither form of decision aid altered the rate of prostate cancer screening 1 year later, said Kathryn L. Taylor, Ph.D., of the Lombardi Comprehensive Cancer Center, Georgetown University, Washington, and her associates.
Decision aids are tools for informing patients about a medical condition – in this case, prostate cancer – and reviewing the possible benefits, harms, and scientific uncertainties regarding screening options. These aids are particularly useful when there are trade-offs between risks and benefits; the efficacy and outcomes of screening are unclear; and/or overdiagnosis and overtreatment are genuine concerns – all of which apply to prostate cancer screening.
Dr. Kathryn Taylor
"Most men overestimate the benefits of prostate cancer screening and are unaware of its limitations," the investigators said.
Decision aids are not intended to either encourage or discourage screening. Instead, they "present the benefits and limitations of screening to help men make choices consistent with their preferences."
Dr. Taylor and her colleagues performed a randomized clinical trial to compare the usefulness of two decision aids against usual care in the long-term (1-year) choice to participate in or refrain from prostate cancer screening. The study subjects were 1,879 outpatients aged 45-70 years, who were recruited from any one of three Washington, D.C., health systems.
This study population was one of the largest and most representative to date to participate in a randomized trial of this issue. African Americans accounted for 40% of the subjects, and about 24% were from lower socioeconomic backgrounds, the investigators noted.
The two decision aids had identical content and were presented at an eighth-grade reading level. Both included general information about the prostate gland, as well as descriptions of screening tests and possible results. They covered treatment options and possible adverse effects, and they reviewed the risk factors for prostate cancer.
Both decision aids encouraged the men to discuss screening with a physician. They also included a values clarification tool and references for further information.
The web-based interactive decision aid had, in addition to these, a narrator who read most of the text aloud, pop-up definitions of medical terms, video testimonials, and animation.
The study subjects were randomly assigned to receive the print decision aid (628 men), the web-based decision aid (625 men), or usual care (626 men). They were assessed at baseline, 1 month after study assignment, and 13 months after study assignment for their knowledge of prostate cancer and prostate cancer testing; the controversy over screening; risk factors; and the benefits and limitations of treatment.
Subjects also reported the conflict they experienced over the decision to participate in or abstain from prostate cancer screening, as well as their satisfaction regarding their most recent decision to either participate in or abstain from screening.
At the 13-month assessment, the subjects also reported whether they had undergone a PSA test, a digital rectal exam, or both during the 1-year follow-up period.
Both decision aids were more effective than usual care in increasing the subjects’ knowledge and reducing their decisional conflict, with effect sizes indicating clinically significant differences, Dr. Taylor and her associates reported (JAMA Intern. Med. 2013 July 29 [doi: 10.1001/jamainternmed.2013.9523]).
This is the first study to find reduced decisional conflict for a year following a decision-aid intervention, and suggests that these tools help men to remain certain about their screening choice.
Even though 90% of the men said that they had access to the Internet and 67% said they used it daily, the web-based decision aid was not significantly more effective than the print decision aid at imparting knowledge or reducing decisional conflict. "In fact, participants in the print arm [of the study] reported significantly greater satisfaction than those in the web arm at the 1-month assessment," the researchers said.
"These results call into question the widespread assumption that interactive, web-based delivery necessarily leads to better outcomes," they added.
At the end of follow-up, 58.3% of the study subjects reported that they had been screened for prostate cancer since their baseline assessment. This rate was "virtually unchanged" from the 59.3% rate of screening they reported before the study commenced.
There also were no significant differences in rates of screening among men given the print decision aid, those given the web-based decision aid, and those given usual care.
These findings suggest that the decision aids offer neutrality and don’t influence the choice of whether or not to undergo screening, "which allows patients and providers to individualize the decision," Dr. Taylor and her associates said.