Study finds high utilization rate on scanners owned by self-referring physicians

In one of the most comprehensive studies ever to examine medical imaging self-referral of privately insured patients, researchers found that physicians who refer patients to themselves or members of their own specialty for diagnostic imaging order imaging more frequently than physicians who refer patients to radiologists for imaging.

The investigation by the Institute of Technology Assessment at Massachusetts General Hospital analyzed more than 526 million claims filed between 1999 and 2003 with an employer-based health insurance plan having about four million members. Dr. G. Scott Gazelle, director of the institute and a professor of radiology at Harvard Medical School, was lead author of the study, published in the November issue of Radiology.

Claims data were grouped according to episodes of care covering six conditions: cardiopulmonary disease, coronary and/or cardiac disease, extremity fracture, knee pain, intra-abdominal malignancy, and stroke. Gazelle and colleagues then categorized each physician's behavior for each of these conditions, establishing if he or she self-referred or radiologist-referred for imaging.

The results indicate that physicians who refer their patients to themselves or to others of the same specialty for imaging use imaging 1.12 to 2.29 times more often than physicians who refer their patients to radiologists for imaging.

The study also found that patient age and comorbidity do not explain the increased frequency for self-referred imaging. After controlling the data set for patient age and comorbidity, imaging frequency was 1.196 to 3.228 times greater for the self-referred patients.

"Some of those who self-refer will say that their patients are sicker, but we found that controlling for the effect of patient age and additional health conditions made the likelihood of imaging among self- or same-specialty referrers even stronger," Gazelle said.

The results indicate that when people have a financial incentive to order or perform a procedure, they're likely to do it more often than when that financial incentive doesn't exist, according to Gazelle.

"From a policy standpoint, I think this adds support to the efforts of the American College of Radiology and others to suggest that if we're trying to control the growth and spending on imaging, we should focus on inappropriate utilization that is related self-referral," he said.

Dr. David Levin, a professor of radiology at Thomas Jefferson University in Philadelphia and lead author of numerous self-referral studies, considers the self-referral problem larger than indicated in Gazelle's study. Levin criticized the study design for focusing only on the professional component of insurance claims, a tactic he believes misses "carloads" of self-referred cases.

"The numbers in this study are impressive enough on their own, but they significantly underestimate the magnitude of the problem," Levin said. "Policymakers have to realize that if we continue to allow self-referral, costs will skyrocket."

Gazelle countered this criticism.

"We admit in the article that we may have a conservative estimate by not looking at ownership, but it's not an issue of specialty," he said. "You could not know from this claims data set who is deriving the technical revenues. It would be impossible to know."

As a next step, Gazelle plans research with data sets from other sources, such as Medicare and Medicaid.

For more information from the Diagnostic Imaging archives:

Analysis encourages comments on CMS fee schedule proposal

CMS proposes 10% rate cut and self-referral restriction in 2008 Medicare physician payment schedule

Study gauges popularity of block leases among California referring physicians

Attorney general joins MRI kickback scheme case