Surgery Center Group Challenges Study Showing Doctor/Owners Operate More Often

A trade group for outpatient surgery centers is challenging a new study that found that doctors invested in the centers perform about twice as many surgeries as doctors with no such financial stake.

The Ambulatory Surgery Center Advocacy Committee, which represents ASC operators, state associations, and the ASC Association, said the report in the April issue of Health Affairs made "incorrect assumptions" about the industry.

"The study authors make inaccurate statements about the relationship between physician ownership of ASCs and higher surgical volume, inferring that physician owners are driven to refer patients to their facility by financial incentives," the ASCAC said in a media release. "While the study authors recognize limitations with their methodology, the ASCAC is particularly concerned with their sole reliance on surgical volume as a proxy for ASC ownership. Volume is not a valid method for identifying which physicians have ownership interests in ASCs. In fact, many non-owners practice at ASCs."

The University of Michigan Medical School study in Health Affairs looked at Florida patients who underwent one of five common outpatient procedures: carpal tunnel release, cataract excision, colonoscopy, knee arthroscopy, and myringotomy with tympanostomy tube placement in the ear.

The researchers determined which doctors were owners of a surgery center. They then compared surgery use among owners in two time periods—before and after they acquired ownership—with that of physicians who remained non-owners.

The study found that while caseloads increased overall between the earlier and later time periods for all physicians—regardless of whether or not they had a financial stake in the surgery center—the increases were more rapid and dramatic among owners.

"Our data suggest that physician behavior changes after investment in an outpatient facility," said study author John Hollingsworth, MD, a Robert Wood Johnson Clinical Scholar at U-M Medical School, in Ann Arbor.

"Through what some have labeled the 'triple dip,' physician owners of surgery centers not only collect a professional fee for the services provided, but also share in their facility's profits and the increased value of their investment," Hollingsworth said. "This creates a potential conflict of interest. To the extent that owners are motivated by profit, one potential explanation for our findings is that these physicians may be lowering their thresholds for treating patients with these common outpatient procedures."

Far from being a driver in rising healthcare costs, ASCAC said the U-M study failed to recognize the lower cost to patients and payers when identical procedures are performed in an ASC as opposed to the hospital outpatient setting. The trade group said Medicare patients save more than 50% on out-of-pocket cost and that ASCs save Medicare approximately 40% annually. By shifting just half of all eligible outpatient surgeries to the ASC setting, Medicare could save an additional $2.3 billion annually, the ASCAC claimed.

The U-M study showed that number of surgery centers has increased nearly 50% over the last decade, largely driven by the investment of physicians, who had a stake in 83% of these facilities. Investment gives doctors more control over their practice, from scheduling to purchasing equipment. For patients, these centers often have shorter wait times than hospitals, according to the report.

The ASCAC pointed to a 2009 study by KNG Health Consulting that showed that 70% of ASC volume growth between 2000 and 2007 was because of migration from hospitals to ASCs.