Laurence Parker PhD, Abstract Co-Author: Nothing to Disclose

David C. Levin MD, Abstract Co-Author: Consultant, HealthHelp Board of Directors, Outpatient Imaging Affiliates, LLC

Andrea J. Frangos MPH, Presenter: Nothing to Disclose

Richard Earnest Sharpe MD, MBA, Abstract Co-Author: Nothing to Disclose

Vijay Madan Rao MD, Abstract Co-Author: Nothing to Disclose

This study examines geographic variation in utilization of magnetic resonance imaging (MRI). Currently, there is great concern about large increases in the utilization of high-technology, high-cost imaging, such as MRI. Policymakers are also extremely interested in geographic variation in utilization rates, which may suggest over- or under-utilization.

The data sources for the study were the Center for Medicare and Medicaid Services (CMS) Medicare 5% Part B Carrier and Beneficiary files for 2007. We extracted all allowed MRI claims for fee-for-service Medicare beneficiaries from the carrier file and merged it with the beneficiary file. This file provides a variable that identifies the state residence of the beneficiary of each service. We tabulated beneficiaries in each state and calculated utilization rates/1000 beneficiaries and 95% confidence intervals (CI) for each state and overall, for head, spine, musculoskeletal (MSK), body, cardiac, vascular and total MRI.

Results: Overall MRI utilization was 189.4/1000 beneficiaries. The five highest states were; Florida, 262; Delaware, 249; Maryland, 223; Texas, 219; and, Nevada, 218. The five lowest were Vermont, 120; Idaho, 128; North Dakota, 133; Oregon, 138; and Iowa, 139. Because the denominators are so large, the 95% CI for the total sample is 0.6/1000, the largest state 2.0, and the smallest, 14.5. Ratio of highest to lowest state MRI utilization is: All, 2.2; Spine, 2.4; Head, 2.6; MSK, 3.3; Body, 3.4; Vascular, 40.4; and Cardiac, 67.8.

There is substantial statewide geographic variation in Medicare MRI utilization, a bit more than two-fold overall. This means that the beneficiaries in the highest utilization state receive 120% more MRIs than in the lowest state. This is more than the percentage increase in MRI utilization over the last decade, which has so concerned policymakers. However, this is considerably less than an eight-fold statewide variation in payments which is frequently cited. Head and Spine MRI, mature, established techniques, show about 2.5-fold variation; MSK and Body MRI, still growing areas of MRI, show a bit more at 3.3-fold variation; and, Cardiac and Vascular MRI, in their infancy, show, unsurprisingly, enormous variation in very low rates of utilization. The issue of variation in imaging deserves further study, both for over- and under-utilization concerns.  

N.A.

Parker, L, Levin, D, Frangos, A, Sharpe, R, Rao, V, Utilization of Magnetic Resonance Imaging: Geographic Variation across States in the Medicare Population—2007.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009563.html