How a decision aid reduced men’s interest in PSA screening


Recent clinical practice guidelines from the United States Preventive Services Task Force (USPSTF) recommend against PSA screening for men of all ages, while other guideline groups, including the American Urological Association (AUA) and the American College of Physicians (ACP), recommend a shared decision making (SDM) approach to the prostate-specific antigen (PSA) test. “Dueling guidelines” can create confusion for people who are facing a health decision, as well as for their clinicians.

A team of authors from the Informed Medical Decisions Foundation/Healthwise and colleagues at Massachusetts General Hospital (MGH) and Dartmouth-Hitchcock Medical Center (DHMC) published a paper in the April 29 issue of the American Journal of Preventive Medicine titled “Responses to a Decision Aid on Prostate Cancer Screening in Primary Care Practices.” MGH and DHMC were two of the Foundation’s demonstration sites for the implementation of shared decision making using patient decision aids (pDAs). The paper focused on the results of providing a pDA on the controversial decision of whether or not to be screened for prostate cancer.

At these two sites, a total of 1,041 men received a DVD-based PSA decision aid addressing the pros and cons of PSA testing, and they answered a questionnaire before and after viewing it. The PSA decision aid was developed by the Foundation and Health Dialog, our production partner before the merger with Healthwise. The questionnaires addressed men’s leanings regarding having a PSA test both before and after viewing the DVD, and men’s knowledge about the key facts regarding the PSA. In addition, at DHMC, men provided answers to a follow-up questionnaire given after their next clinician visit.

The results of the study addressed three important questions in shared decision making.

First, before watching the decision aid, 43 percent of men were leaning toward having a PSA test, 32 percent were unsure, and 25 percent were leaning against having a PSA test. After the decision aid, 38 percent of men were leaning toward having a PSA test, 17 percent were unsure, and 44 percent were leaning against. Thus, the pDA primarily shifted men who were initially unsure to leaning against PSA testing. This phenomenon of people who are unsure about a medical intervention “coming off the fence” in a more conservative direction confirms similar results with, for example, decisions about joint replacement for hip and knee osteoarthritis at Group Health.

Second, men were well-informed after viewing the pDA; 70 percent could answer all five knowledge questions correctly. And the more knowledge questions they could answer, the more they leaned against PSA testing. However, even among the best-informed men who could answer all the knowledge questions correctly, 37 percent still wanted a PSA test. These data show that the PSA decision is “preference-sensitive,” supporting the guidelines from the AUA and ACP over the USPSTF.

Finally, and perhaps most importantly, patient responses to the pDA viewed prior to a clinician visit were strongly related to the content of the visit. This finding is important because many experts worry that SDM must be done only during a face-to-face visit, or else clinicians may disregard patients’ preferences when decisions are made. The study found that when men indicated that they planned to have a PSA discussion with their clinicians, 68 percent did so, compared to 35 percent for men who did not plan to discuss PSA testing. And when a recommendation about PSA testing was made by the clinician, it tended to agree with the patient’s leaning. When men were leaning toward a PSA test, clinicians recommended a PSA 78 percent of the time, and when men were leaning against a PSA, clinicians recommended a PSA 30 percent of the time.

These results, taken together, confirm that a shared decision-making process between a patient and a clinician, supported by decision aids, can be used to resolve the PSA screening controversy, one man at a time.

Michael J. Barry is president, Informed Medical Decisions Foundation.

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