Men hear little about negative aspects of PSA testing

NEW YORK (Reuters Health) - Few men about to be tested for prostate specific antigen (PSA) levels cannot make an informed choice because their healthcare providers fail to address both the pros and cons of testing, according to results from two studies reported in the September 28 Archives of Internal Medicine.

As Dr. Richard M. Hoffman and his team maintain, "Prostate cancer screening is controversial because there is no convincing evidence that screening reduces disease-specific morbidity and mortality." Furthermore, "There are considerable data suggesting that treatments for early stage cancers - the targets for screening - may lead to important complications and are only marginally beneficial, especially for men 65 years and older."

Dr. Hoffman, at the University of New Mexico School of Medicine in Albuquerque, and his associates conducted a telephone survey of a nationally representative sample of 3010 respondents age 40 years and older. A subset of 375 men had either undergone or discussed PSA testing with their health care provider in the previous 2 years.

The subjects' comments indicate that 69.9% discussed screening before making a testing decision, including 14.4% who decided to not be tested.

In fact, "a healthcare provider's recommendation (odds ratio 2.67) was the only discussion characteristic associated with testing," the authors note.

Healthcare providers' advice was highly prized, even though nearly three-fourths restricted their comments to positive aspects of testing; fewer than one-third addressed disadvantages.

Only 20.6% of subjects reportedly discussed both the pros and cons of PSA testing and being asked their preference for testing.

Even though most of the subjects felt "very well informed about prostate cancer," 92.8% could not correctly answer more than one of three knowledge questions.

Thus, Dr. Hoffman's team summarizes, "Most prostate cancer screening decisions did not meet criteria for shared decision making because subjects did not receive balanced discussions of decision consequences, had limited knowledge, and were not routinely asked for their preferences."

They recommend that health care providers use other strategies, such as decision aids, to ensure that all facets of informed consent be covered.

In an editorial that closely examines shared decision making, Drs. Steven H. Woolf and Alex Krist, from Virginia Commonwealth University, Richmond, comment that, because of the many associated challenges, "shared decision making is unlikely to gain its footing in routine patient care."

"What is ultimately required," the editorialists maintain, "is a deeper change in culture among providers and consumers of health care to delay dissemination, resist the assumption that newer is better, wait for evidence, tolerate observation over intervention, and accept uncertainty."

In the second paper, Australian investigators at the University of Sydney advocate the use of a decision aid to assist in shared decision making. To provide data required for such an aid, they accessed several sources, and using a Markov model, compared outcomes for men who participate in annual PSA screening and those who never undergo the test.

The model assumed 100% annual participation in the screening cohort for men at ages 40, 50, 60, or 70, and 0% participation in the nonscreening cohort. For each group they estimated prostate cancer incidence and mortality, as well as mortality due to causes other than prostate cancer. Thus, the data were tailored by age and by risk status based on family history.

These estimates, Dr. Kirsten Howard and associates explain, "should help men and physicians achieve the goal of full discussion of the benefits and risks of PSA screening, as recommended in clinical practice guidelines and advice from health agencies."

"It is striking that the absolute mortality benefit is small even in men at the highest levels of familial risk and even when prostate cancer death are cumulated to 85 years of age," reflecting "the relatively small proportion of overall deaths due to prostate cancer."

On the down side of being screened and treated for prostate cancer are such problems as erectile dysfunction or impotence, urinary incontinence, and bowel problems.

Researchers interested in testing decision aids in their setting can obtain the model by request.

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