Bending the curve: the recent marked slowdown in growth of noninvasive diagnostic imaging

The purpose of this article is to determine whether there has been any change in the rapid growth pattern that has characterized noninvasive diagnostic imaging in recent years.

The annual nationwide Medicare Part B databases were used. All Current Procedural Terminology codes for discretionary noninvasive diagnostic imaging were identified. The overall utilization rates per 1,000 fee-for-service beneficiaries were calculated from 1998 through 2008, as were rates by modality. Determination was made as to whether studies were interpreted by radiologists or nonradiologist physicians.

The total utilization rate of noninvasive diagnostic imaging grew at a compound annual growth rate of 4.1% from 1998 to 2005, but this decreased to 1.4% from 2005 to 2008. From 2005 through 2008, the overall growth trends flattened dramatically for MRI and nuclear medicine and abated somewhat for CT, ultrasound, and echocardiography. In ambulatory settings, flattening of the advanced imaging growth curves was seen in both private offices and hospital outpatient facilities. From 1998 to 2005, the compound annual growth rate was 3.4% among radiologists and 6.6% among nonradiologist physicians. From 2005 to 2008, the compound annual growth rate decreased to 0.8% among radiologists and 1.8% among nonradiologists.

There has been a distinct slowing in the growth of discretionary noninvasive diagnostic imaging in the Medicare fee-for-service population since 2005. The slowdown has been most pronounced in MRI and nuclear medicine. This should allay some of the concerns of policymakers and payers. Both before and after 2005, growth was approximately twice as rapid among nonradiologist physicians as among radiologists.