Radiologists Have Little Influence Over Expensive Imaging

James Brice

November 28, 2011

November 28, 2011 — Radiologists might hold overall medical responsibility over high-tech diagnostic imaging, but they have little say over its specific use.

A new study has found that only 5.3% of high-cost medical imaging exams were performed because of a radiologist's recommendation for a follow-up study.

The findings, published online November 14 in Radiology, have punched a hole in the theory that radiologists have contributed to rising medical imaging costs by persuading referring physicians to order expensive follow-up imaging.

"We examined how often a recommendation for additional imaging actually leads to a study being performed," first author Susanna I. Lee, MD, PhD, from the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, in Boston, told Medscape Medical News. "It is actually a lot less often than you would think."

The findings are a based on a retrospective evaluation of 29,232 chest and abdominal computed tomography (CT) studies, brain and lumbar magnetic resonance imaging (MRI) studies, and body positron emission tomography studies performed from July to December 2007 at 8 acute care hospitals and 19 clinics affiliated with Partners Healthcare, Boston.

Dr. Lee and colleagues found that only 1558 of those studies could be tracked back to a radiologist's recommendation for follow-up imaging.

Less Than 50% Compliance

A previous data-mining investigation by Dr. Lee's colleagues revealed that radiologists at Partners Healthcare facilities recommended additional imaging in their dictated reports for 12% of initial diagnostic imaging studies in 2007 (Radiology. 2009; 253[2]:453-461).

Taken together, the 2 sets of findings suggest that referring physicians follow about half of their radiologists' recommendations for additional imaging.

Dr. Lee and colleagues note that low compliance is not surprising, considering the number of variables a referring physician considers when formulating appropriate patient management.

"You may have a CT study with a finding of a liver lesion," he said. "That gives you the option of following up with MRI, biopsy, or excision, or the physician may have access to prior imaging that already indicates the cancer is stable."

Challenge to Self-Referral Theory

The findings raise doubts about the theory that radiologist recommendations for high-tech imaging follow-ups inflate medical imaging costs.

Some published studies have suggested their economic impact is substantial.

A 2007 study of emergency department imaging at a single hospital, for example, reported that radiologists recommended additional imaging for 31% of emergent abdominal CT scans (Am J Emerg Med. 2007;25[4]:396-399). In that study, it was estimated that compliance with such recommendations would cost $242 per patient, and translate into $226 million annually when extrapolated to all emergency departments.

Unlike researchers who examined estimated recommendations alone, Dr. Lee and colleagues looked at the portion of recommendations that actually resulted in more procedural volume.

"This is what makes this study unique," she said.

But radiologists should not try to use these findings as proof that their impact on imaging self-referral is inconsequential. "They could say that, but my response would be, 'nice try'," Leslee J. Shaw, PhD, president of the American Society of Nuclear Cardiology and professor of medicine and outcomes researcher at Emory University, Atlanta, Georgia, told Medscape Medical News. Nuclear cardiologists have been singled out as a source of costly office-based self-referral.

Instead of showing that radiologists are not contributors to wasteful, inappropriate imaging, the study suggests to Dr. Shaw that radiologists should try to exert more influence to prevent it.

"The fact that the studies are ordered in small part with the help of recommendations of radiologists undervalues their role in educating [referring physicians about] what is inappropriate," she said.

Still, this study indicates that follow-up imaging was most often performed when a solid professional consensus favored it.

In the study, 36.4% of CT exams performed after a radiologist's recommendation were used to monitor small pulmonary nodules. Nearly 10% of high-cost follow-up imaging after a recommendation is related to pulmonary parenchymal abnormalities.

Guidelines from the Fleischner Society, published in 2005, encourage repeat imaging of small pulmonary nodules. Recently, results from the National Lung Screening Trial validated those recommendations, Dr. Lee said.

The appropriate course of action is less clear for follow-up imaging recommended because of the initial incidental detection of adenopathy and renal lesions. More than 6% of these follow-up imaging procedures were associated with such indications. American College of Radiology Appropriateness Criteria offer guidance about their use, but definitive data on the value of follow-up imaging for such cases are still lacking, Dr. Lee said.

The study was limited because results were drawn from a single set of affiliated academic hospitals and clinics. Researchers did not measure compliance variations among various hospitals. Referrals from outside healthcare facilities were not considered; results might be different when community hospitals, freestanding clinics operated by physician group practices, and hospitals in regions outside of New England are analyzed.

The study authors have disclosed no relevant financial relationships

Radiology. Published online November 14 2011. Abstract


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