ACR Study: High-Tech Radiology Services Lead Recent Growth in Radiology Utilization
The use of high-tech radiology services, such as MRI and interventional radiology, experienced tremendous growth during the 1990s while traditional radiology services remained about the same, according to a new study conducted by senior ACR staff members. Moreover, there is a wide variation in utilization rates across states and census regions.
The study, "Utilization of Radiology Services in the United States: Recent Levels and Trends in Different Modalities, Regions, and Populations," was authored by ACR Assistant Director for Research Mythreyi Bhargavan, PhD, and Senior Director for Research Jonathan Sunshine, PhD.
"This is the first large-scale study conducted that looks closely at the growth rates for the more recent high-tech imaging modalities," Bhargavan said. "This information will be valuable to practices, payers, and health care policy makers in planning future growth and will allow them critical data for making financial decisions and negotiating contracts."
The study evaluated Medicare data between 1995 and 2001, which included between 100 and 130 million diagnostic radiology procedures and 30 million enrollees for each year. Utilization levels were measured for each physician Current Procedural Terminology code, state, and place of service.
For 2001, nonmanaged care Medicare patients averaged 2,859 diagnostic and 266 therapeutic radiology ambulatory procedures per 1,000 individuals. For all places of service, the average was 4,176 diagnostic and 274 therapeutic radiology procedures per 1,000 patients. According to the study, nearly one half of all diagnostic procedures were classified as general radiology; sonography was the second-most reported modality.
"In ambulatory settings, high-tech procedures such as MRI, interventional radiology, and nuclear medicine grew over 10% per year on average, and CT and sonography grew at approximately 8% annually between 1992 and 2001," the study reports. "In contrast, general radiology, which numerically comprises by far the largest portion of all procedures, grew at only 1% annually."
Screening mammography among the Medicare population also grew rapidly between 1998 and 2001, "probably because of increased awareness and the uptake of recently instituted coverage, but also possibly reflecting procedures formerly misclassified as diagnostic mammography when the screening mammography coverage under Medicare was still new."
The study notes the relationship between a modality's growth rate and how long it has been available. For instance, general radiology, the most widely available modality, "has essentially stopped growing, suggesting that modalities eventually plateau in utilization." Meanwhile, "MRI is the newest modality and the most rapidly growing, indicating modalities grow especially rapidly (in percentage terms) in their early stages."
Overall, Medicare data indicate that the total number of radiology procedures per 1,000 enrollees increased at a compound annual average rate of almost 5% between 1998 and 2001.
"This is a rapid increase, and implies almost a doubling of per capita utilization every decade," the report concludes. "This growth, sometimes called 'technological progress,' is a measure of the increasing power of radiology to help patients."
However, the report notes, while this growth obviously benefits patients, "it entails a major problem for radiologists" in the form of a radiology workload that is growing about 8% annually.
"It seems that radiologists must either continue to rapidly increase the workload they handle—possibly through technological advances such as 3D 'fly-through' viewing of cross-sectional modalities and computer-aided detection—or see a greater portion of the radiology workload fall to other specialties, as is already happening with nuclear cardiology," the report cautions. "Indeed, the most likely course is that both will continue to occur quite rapidly.
"The correlation between the number of procedures per 1,000 Medicare enrollees in 2001 and the total number of Medicare providers in the state was positive and statistically significant," according to the report. "In addition, the correlation between the number of procedures per 1,000 Medicare enrollees in 2001 and total radiologists, and between the number of procedures per 1,000 Medicare enrollees in 2001 and total state population, was positive and statistically significant."
And the sharp increase in the growth rate of high-tech imaging procedures is not limited to Medicare patients. The study cites an issue brief from the Center for Studying Health Systems Change that suggests health care utilization and costs are, overall, increasing rapidly.
According to the report, not only is there an increase in the rate of growth of radiology utilization in Medicare, but the limited managed care data indicate "a much more rapid growth" in that sector of the health care delivery system.