Mark D. Hiatt MD, MBA, Presenter: Medical Director, Regence BlueCross BlueShield Board Member, RadSite Former Chief Medical Officer, HealthHelp, LLC

Mark S. Holdaway BS, Abstract Co-Author: Nothing to Disclose

To observe the degree to which cardiac MRI, CT, SPECT, and PET (non-echo procedures) may substitute for echocardiography (echo) by examining the ordering patterns of providers before and after the recent implementation of a program to manage the utilization of echo, with the resulting need to seek prior authorization considered an additional "cost" of ordering echo under demand theory in economic science.

The ordering of echo and non-echo procedures, as defined by Current Procedural Terminology code and discerned through claims data, by providers in 4 states in the United States caring for approximately 1.5 million commercial and Medicare members of a health insurance plan was tracked from the beginning of November 2010 to the end of October 2013. A program to manage outpatient echo utilization, administered by a radiology benefit manager, was instituted in December 2012. (A similar program to manage non-echo utilization had been in place at the time of this implementation, beginning in June 2009 and phased in during subsequent months.)

During the 3-year study period, 265,704 echo and non-echo procedures were performed in the population under review. With the implementation of echo utilization management (UM), the relative ordering of echo and non-echo procedures changed as anticipated, declining by 4.1% for echo (from 48.4 to 46.4 units per 1,000 members), but increasing for non-echo procedures by 3.8% after echo UM implementation, compared to a decrease of 3.7% before implementation (yielding an overall decline from 12.3 to 11.5 units per 1,000 members).

The cross elasticity of demand between echo and cardiac MRI, CT, SPECT, and PET is positive, as apparent substitution was observed as a result of the recent program implementation. Other confounding factors may have been at play during the study period, including rising concern about excessive medical radiation (except, of course, for MRI) and campaigns to address inappropriate ordering such as the Choosing Wisely initiative; however, these influences would have tended to reduce, not increase, non-echo utilization as a whole, thus supporting the hypothesis of substitutability.

These results suggest that ordering patterns for diagnostic imaging may be less entrenched than expected, with such other considerations as changes in relative ordering convenience overcoming ingrained preferences for modality.

Hiatt, M, Holdaway, M, Echocardiography Manifests Substitutability with Other Cardiac Imaging Modalities in the Ordering Patterns of Referring Providers.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016834.html