Urologist Ownership of Imaging Centers Affects Self-Referral Rates

Urologists who treat men with prostate cancer are 2.5 times more likely to refer patients to intensity-modulated radiation therapy centers, especially if they have a financial stake in the IMRT center.

Urologists whose private practices own intensity-modulated radiation therapy (IMRT) equipment are 2.5 times more likely to prescribe the treatment to patients with prostate cancer than they were before they began offering the technology in-house, according to a comprehensive review of Medicare claims published in the New England Journal of Medicine (NEJM). The study, “Urologists’ Use of Intensity-Modulated Radiation Therapy for Prostate Cancer,” echoes an earlier Government Accountability Office (GAO) report, “Medicare: Higher Use of Costly Prostate Cancer Treatment by Providers Who Self-Refer Warrants Scrutiny.”

The study, authored by Jean M. Mitchell, PhD, an economist and professor at the McCourt School of Public Policy at Georgetown University, analyzed treatment patterns of urologists before and after they acquired ownership of IMRT services and compared the patterns to a matching group of non—self-referring urologists who were in private practice or who provided clinical services at National Comprehensive Cancer Network (NCCN)-designated cancer centers (also non–self-referrers). Claims data were collected from more than 45,000 patients from 2005 through 2010.

The study has caused controversy within the field of urologic cancer care, where the issue of whether group practices should be allowed to offer ancillary services, including IMRT, has been a topic of recent debate. Although there is a federal prohibition for self-referral under the Ethics in Patient Referrals Act, ancillary services are allowed.

The Large Urology Group Practice Association (LUGPA) wrote a rebuttal to Mitchell’s study, saying it was flawed and questioning the motivation of the group that funded it.

The study found that, among the cohort of self-referring urologists in private practice, the use of IMRT services increased from 13.1 (pre-ownership period) to 32.3% (ownership period), an increase of 19.2 percentage points. Approximately 6.0% of the men treated by self-referring urologists underwent IMRT performed by non—self-referring providers.

Among non—self-referrers, IMRT use increased 1.3 percentage points, going from 14.3% during the pre-ownership period to 15.6% in the ownership period. For urologists working at NCCN centers, the IMRT rate remained stable at 8.0%. When claims data for the matching self-referring groups were reviewed, the IMRT rate increased by 33.0 percentage points.

Mitchell concludes that “men treated by self-referring urologists, as compared with men treated by non—self-referring urologists, are much more likely to undergo IMRT, a treatment with a high reimbursement rate, rather than less expensive options, despite evidence that all treatments yield similar outcomes.”

The study was funded by the American Society for Radiation Oncology (ASTRO). In a statement, ASTRO Chairman Colleen A.F. Lawton, MD, said "Dr. Mitchell's study provides clear, indisputable evidence that many men are receiving unnecessary radiation therapy for their prostate cancer due to self-referral. While I am a prostate cancer specialist impassioned to eradicating the disease, I am equally dedicated to utilizing these powerful technologies prudently and in the best interest of each individual patient. We must end physician self-referral for radiation therapy and protect patients from this type of abuse."

LUGPA contends that ASTRO’s motivation for seeking an end to ancillary services is to recapture lost market share by eliminating competition in the use of IMRT—a charge Lawton has denied.

In a recent article for Urologists in Cancer Care, Deepak A. Kapoor, MD, and Judd W. Moul, MD, noted Mitchell’s finding that 32.3% of patients with newly diagnosed prostate cancer who sought treatment from integrated urology groups in 2005-2010 received IMRT. They said that percentage is nearly identical to that of similar groups of patients tracked in historical studies going back as far as 1992, before group practices offered in-house radiation services.

They added that, according to Mitchell’s data, active surveillance rates were nearly the same between integrated groups and groups that refer patients out for IMRT; active surveillance rates increased in large groups after they acquired IMRT equipment; and as IMRT use has increased, brachytherapy administration has decreased, a pattern they said mirrors national trends and practice guidelines.

Finally, Kapoor and Moul argued that Mitchell’s control and study groups were not well matched, that the cited percentage of NCCN IMRT use was too low to be credible, and that the multidisciplinary case discussions that now occur in large urology groups have contributed to more patients opting for IMRT.

“Shifts in healthcare delivery patterns are inevitable—and healthy—as medicine becomes more integrated, historical monopolies over certain services are eliminated, and patients seek care in specialized treatment centers that are convenient and cost-effective,” the doctors wrote. “The focus of any responsible physician should be on ensuring access to affordable care that produces the best results—not on where that care is delivered.”

Mitchell JM. Urologists' Use of Intensity-Modulated Radiation Therapy for Prostate Cancer. N Engl J Med. 2013;369(6):1629-1637.