Practice patterns of radiologists and nonradiologists in utilization of noninvasive diagnostic imaging among the medicare population 1993-1999

PURPOSE: To compare nationwide trends in noninvasive diagnostic imaging (NDI) practice patterns of radiologists and of nonradiologists among the Medicare population during the 6 years from 1993 to 1999. MATERIALS AND METHODS: Medicare Part B claims files from 1993, 1996, and 1999 were analyzed for all procedure codes related to NDI. NDI codes were classified into 22 diagnostic categories within seven imaging modality groups. For the services were classified as radioloists or nonradiologists by using the provider specialty code designated in claims in the files. The data were analyzed to determine the overall utilization rates and relative value unit (RVU) rate changes between 1993 and 1999 among radiologists and nonradiologists. RESULTS: In 1993, the overall NDI utilization rate per 100,000 Medicare fee-for-service beneficiaries was 215,652 for radiologists and 79,942 for nonradiologists. In 1999, the rate was 207,270 for radiologists and 100,059 for nonradiologists, which is a 3.9% decrease among radiologists and a 25.2% increase among nonradiologists. In the 6-year interval from 1993 to 1999, the overall RVU rate increased 6.9% among radiologists and 32.4% among nonradiologists. The percentage of NDI performed by radiologists decreased from 73.0% in 1993 to 67.4% in 1999. CONCLUSION: Overall, the utilization rate of advanced, high-technology imaging is increasing among both radiologists and nonradiologists. However, it is increasing at a considerably more rapid rate among nonradiologists.