Physicians who purchase an MRI system order significantly more scans than doctors who don't own the modality, a new study found.

In a paper published in Health Affairs this month, author Laurence C. Baker, a professor of health research and policy with Stanford University, sought to examine the association between physicians' acquisition of MRI equipment, use of the modality by patients and health care spending.

For the study, Baker looked at a 20 percent random sample of Medicare claims submitted between 1999 and 2005 by neurologists and orthopedists. He compared the MRI rates and costs between those specialists who didn't bill for MRI scans and those who did bill for the exams within the study's time frame.
Of the total 11,844 orthopedists studied, 3,535 began billing for MRI during the study. Out of the 5,993 neurologists analyzed, 706 began billing for the procedures. Imaging rates rose significantly for both specialties - per 100,000 claims, the use increased from 46 to 72 images among orthopedists and from 48 to 83 images among neurologists, according to the study.

Baker pointed out that there were no major differences in the pre-billing period for owners and non-owners of MRI equipment. "But at the time of acquisition of MRI, there was a distinct (and strongly statistically significant) increase," he wrote in the study. "In the first quarter after they began billing, orthopedists jumped from using about 20 more MRIs per 1,000 episodes than traditional users to using about 45 more. Neurologists jumped by more, increasing their rate by about 60 to nearly 140 procedures per 1,000 episodes more than traditional users."

When Baker looked at the effects on spending associated with beginning to bill for MRI, he found that outpatient spending for orthopedists rose by an average of $25 per case (about a 2 percent increase) and around $91 for neurologists (about a 6 percent increase).

In his discussion of the reasons for increased MRI use, Baker noted the lucrative reimbursement rates of the time. "One of the important features of the time period over which this study took place was the generous reimbursement for in-office imaging built into the Medicare fee schedule," said Baker. "This, along with generous reimbursement by private payors, was probably an important factor driving physicians' acquisition of the technology."

Another potential explanation for the increase is the convenience that comes with equipment acquisition, Baker said, since it reduces the hassle of referrals and patient travel to another location. However, he also pointed out that most MRI scans in the study period required an additional visit by patients to the office.

While recognizing the continuously changing landscape of reimbursement policies for medical imaging procedures, Baker said "the results [of the study] should be a powerful reminder of the potent forces at work when physicians acquire new and advanced equipment and gain the ability to bill directly for its use."

More Industry Headlines