Not that this is anything earth shattering, but the American Journal of Roentgenology published a study last year documenting the statistically significant difference in rate of MRI utilization among two orthopedic surgical groups. The study was titled: Physician Self-Referral of Lumbar Spine MRI With Comparative Analysis of Negative Study Rates as a Marker of Utilization Appropriateness. In the study, one group owned their MRI equipment and the other group did not.
The group hypothesized that a financial interest in imaging equipment may affect the imaging referral patterns of ordering physicians. What method did these authors use? This was a retrospective review of 500 consecutive diagnostic lumbar spine MRI examinations (250 scans from each group) in one radiology practice ordered by two separate referring physician groups in the same community. Negative examinations and the total number of lesions per positive study were recorded for each group.
One measure of the appropriateness of ordering imaging studies is the proportion of normal studies. Too many normal studies implies excessive test ordering. What did this study discover? In the orthopaedic group that owned their MRI equipment, the negative scan frequency was 86% higher (p<0.0001) while the number of positive lesions per scan showed no significant difference between the two practicing groups, suggesting a similar severity of disease between the two populations. In addition, patients were significantly younger in the physician group with a financial ownership in the MRI.
What does this study suggest? It suggests that medical decisions by physicians may sometimes be guided by a financial interest in self referral patterns. Is this shocking? Of course not. If you own expensive radiology equipment, that equipment must be paid for. And if you are both the ordering physician and owner of the equipment, it is no easier or harder to document medical necessity than if the equipment is owned by another party.
Could this study be extrapolated to other physician specialties and other diagnostic imaging equipment. The answer is more appropriately asked why couldn't it be. How is an orthopedist owning their own MRI any different than any other physician owning their own diagnostic imaging equipment.
Based on this research (as well as common sense), if we accept the premise that physicians who own their own equipment are more likely to over utilize the equipment (which is probably true under most circumstances) and if we don't want to ban the practice of physician self referral to office diagnostic imaging for which they have a financial interest (as a convenience for patients), then what is the solution? Should CMS continue to pay for the over utilization of the equipment?
I would say no. We should not be paying for stuff that is not necessary. And until that day happens we should at least start paying less for it. Maybe now is the time for Medicare to introduce a physician self referral payment penalty for the facility fee (and the reading fees) associated with use of diagnostic imaging that are also owned by self referring physicians. If physicians can't resist the temptation to over utilize their own diagnostic imaging for financial gain (which also increases patient risk of harm), perhaps they should stop getting rewarded for it. Since we are all potential patients some day, including us physicians, we should all want this incentive eliminated for good.
