PSA Screening Overused Among Frail Elderly at VA Facilities

Jenni Laidman

January 12, 2012

January 12, 2012 — Severely ill elderly men are often screened for prostate cancer at Veteran's Affairs (VA) facilities, especially in the South, even though the test can potentially do more harm than good, according to a study published online December 17 in the Journal of General Internal Medicine.

The study, conducted by Cynthia So, MPH, from the University of California, San Francisco, School of Medicine, and colleagues, also revealed that VA centers lacking academic affiliation, as well as those with a higher ratio of nurse practitioners and physician assistants to physicians, overtested for prostate cancer among men with limited life expectancies. The study also found that white men were 20% more likely to receive unnecessary screening than black men, and that younger men, married men, and those with higher socioeconomic status were also more likely to be overtested.

"Some VA hospitals are screening up to four fifths of their very ill, very elderly patients, and some as few as one quarter, but none are targeting screening according to the men's life expectancy," Louise C. Walter, MD, the study's principal investigator, who is a geriatrician and a professor of medicine at the University of California, San Francisco, said in a news release.

Although several medical groups, including the US Preventive Services Task Force (USPSTF), the American Cancer Society, and the American Urologic Association, recommend against prostate-specific antigen (PSA) testing in elderly men with limited life expectancy, screening rates remain high, with some regions of the United States screening 56% of men aged 80 years and older, and VA hospitals screening 45% of that population in 2003. Because PSA screening is an early-detection modality, the benefits of identifying slow-growing cancers occur years in the future, whereas the risks of testing are immediate, including unnecessary biopsies and such adverse treatment effects as incontinence, impotence, proctitis, and hot flashes.

In this study, researchers analyzed data from the VA National Data Systems of 622,262 men aged 70 years and older who were seen at 104 VAs in 2003. The authors found that nearly a third of the VA centers screened more than half of men with a limited life expectancy resulting from a combination of age and disease state.

Screening rates among men with a limited life expectancy ranged from 25% to 79% (median, 43%). Higher screening rates were associated with no academic affiliation by the VA center (50% vs 43%; adjusted relative risk [RR], 1.14; 95% confidence interval [CI], 1.04 - 1.25), ratio of physician extenders to physicians of 3:4 or more (55% vs 45%; adjusted RR, 1.20; 95% CI, 1.09 - 1.32), and location in the South (45% vs 39% in the West; adjusted RR, 1.25; 95% CI, 1.12 - 1.40). Screening rates were also higher in the Midwest (43%; adjusted RR, 1.15; 95% CI, 1.02 - 1.30). Risks were adjusted for both patient and medical center characteristics.

The study authors found a “one-size-fits-all approach” with centers that screened a high percentage of men with favorable life expectancies also screening a high percentage of men with short life expectancies. In turn, centers with low screening rates for men with limited life expectancy also were less likely to screen men with favorable life expectancy. This finding indicates "that screening is being poorly targeted," the authors write.

"The screening rate you would expect to see for men with limited life expectancy is zero to 20 percent," Dr. Walter said in the press release. "No medical center we looked at was in that category."

One possible explanation for low screening rates is general dissatisfaction with the PSA test, which often leads to unnecessary biopsies and other procedures, the authors suggest. The USPSTF adopted that position in 2011.

The research uncovered a 3-fold difference in screening by geographic region — a result seen in previous studies using Medicare claims. The higher screening rates may relate to higher healthcare expenditures in general in the South and Midwest, the authors write, as well as beliefs about PSA screening and patient preference.

Previous research has also uncovered an association between academic affiliation and PSA screening that follows nationally recommended guidelines. This could be, the authors write, because academic centers place a greater emphasis on evidence-based medicine, or it may be that the centers place less emphasis on defensive medicine because of reduced risk for malpractice lawsuits.

A new wrinkle in the VA study was the finding that a higher level of midlevel providers, such as physician assistants and nurse practitioners, was associated with a higher rate of unnecessary prostate screening. In a previous study, a greater reliance on physician assistants and nurse practitioners was associated with lower rates of PSA screening of the elderly; however, the authors say, the source of the data in the 2 studies may account for the difference. The previous study used data from providers, whereas this study used medical center data. An alternative explanation is that it could say more about the facility's economic conditions including, possibly, tighter budgets or higher patient volume.

The research failed to find an association between levels of PSA screening among elderly men with low life expectancy and incentives for primary care performance. Nor was there an association between screening rates and scores on prostate screening education, the presence of geriatricians, or the length of a patient's initial visit.

Limitations include study of the VA population, which may not be generalizable; data from 2003, which may not reflect today’s practices; and if PSA testing was paid for by a source other than Medicare, that would not have been captured in the trial data.

The study was supported by the National Cancer Institute at the National Institutes of Health, the Medical Student Training in Aging Research Program at the American Federation for Aging Research, the National Institute on Aging, the New Mexico VA Health Care System, the White River Junction VA, and the VA Health Services Research and Development Service Award. This work was presented at the American Geriatrics Society Annual Scientific Meeting in 2010. The authors have disclosed no relevant financial relationships.

J Gen Intern Med. Published online December 17, 2011. Abstract


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