Do bariatric surgery restrictions improve outcomes?

A Medicare policy limiting where people can undergo weight-loss surgery to so-called "centers of excellence" was not responsible for reducing complications from the procedures, according to a new study.

In 2006, the Centers for Medicare & Medicaid Services (CMS) said it would only pay for bariatric surgery done at hospitals that had certain equipment and medical teams in place and were certified by the American College of Surgeons or the American Society for Metabolic and Bariatric Surgery (ASMBS).

"About a decade ago, there were very real concerns that there were safety problems with bariatric surgery," said Dr. Justin Dimick, who led the new study at the University of Michigan in Ann Arbor.

At some hospitals, he said, as many as nine percent of patients died during or after surgery.

But that started changing before CMS stepped in with new restrictions, according to Dimick, in part due to less-invasive surgical techniques and better surgeon training.

He and his colleagues used billing codes to track bariatric surgery complications, such as leaks and bleeding, during about 300,000 procedures done between 2004 and 2009 both at centers of excellence and at other hospitals.

They found the proportion of patients on Medicare who had any procedure-related complication dropped from 12 percent before the policy change to eight percent afterward, according to findings published Tuesday in the Journal of the American Medical Association.

Dimick and coauthors report on the complications following bariatric surgery before vs after implementation of a national policy restricting coverage to centers of excellence. In an accompanying Editorial, Greenberg discusses promoting quality surgical care.

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Whether the CMS restriction of bariatric surgery to COEs is associated with improved outcomes remains uncertain. Previous studies comparing COEs with non-COEs have largely failed to identify better outcomes at COEs. In contrast, studies examining outcomes before and after the CMS national coverage decision have suggested a beneficial effect of the CMS policy restricting bariatric surgery to COEs.

However, because these latter studies lacked a control group, they were unable to isolate the effect of the CMS national coverage decision from the many other unrelated factors that may have improved bariatric surgery outcomes during the same period. For example, improved outcomes could have been due to the use of lower risk procedures (eg, laparoscopic gastric banding), increasing surgeon experience, fellowships for advanced training in laparoscopic bariatric surgery, or healthier patients undergoing surgery due to broader acceptance of weight loss surgery.

In this study, we sought to evaluate whether the COE component of the national coverage decision was associated with improved bariatric surgery outcomes in Medicare patients. Our objective was to examine outcomes in Medicare patients before compared with after the implementation of the CMS policy that restricted coverage of bariatric surgery to hospitals designated as COEs. We controlled for secular trends using a control group of non-Medicare patients to better account for other factors that may have lead to improved outcomes with time, independent of the CMS policy.