Self-referral is not the biggest contributor to the growth of in-office imaging by physicians, according to a report prepared by the Lewin Group for a coalition of physicians and medical groups. Rather, it's the immediate access to imaging results and the expanded uses for diagnostic imaging that drive the growth of these technologies. The report appears to debunk the concern among some policymakers that physicians who own imaging equipment are overusing the technology for financial gain, allowing Medicare Part B to foot the bill. Reductions in the Medicare Physician Fee Schedule's conversion factor in 2002 resulted in a significant reduction in the growth in Medicare-allowed charges for imaging between 2001 and 2003.

The researchers say that if self-referral were an important driver of the number of imaging services, they would have seen an acceleration in the growth of imaging services from 2001 to 2003 to offset the reductions in physician income brought about by reductions in the conversion factor. This did not, in fact, occur. The researchers caution that restrictions on self-referral of imaging services may reduce beneficiaries' access to these services. Mohit Ghose of America's Health Insurance Plans says this report could lead to more transparency. "Once consumers see how much imaging tests cost and how these tests affect the health care dollar, they can interact better with the health care system."

Growth in the volume of physician-billed services, 1999–2003

Source: Issues in the Growth of Diagnostic Imaging Services: A Case Study of Cardiac Imaging, the Lewin Group.