The introduction of a computerized radiology order entry (CROE) system with decision support capabilities into an integrated multispecialty group practice may substantially reduce the growth rate of high-cost outpatient imaging volume, according to the results of a seven-year, time-series analysis published online in the journal Radiology.

The study, conducted by researchers at the University of Florida Health Center in Gainesville, Fla., and Massachusetts General Hospital in Boston, demonstrates the clear benefit of using appropriateness criteria to help curb growth rates in advanced imaging utilization.

For diagnostic imaging clinicians, this work is of particular import as proposed legislation aims to curb imaging orders for Medicare beneficiaries via the implementation of pre-authorization for all imaging studies on this population.

“No other branch of medical technology has experienced the explosive growth in volume and variety of available services that radiology has during the past two decades,” the authors wrote. “The medical care industry in the United States has purchased and installed advanced radiology equipment at an astounding rate, outpacing all other countries.”

Christopher L. Sistrom, MD, and colleagues evaluated the effect that certain appropriateness criteria measures--specifically a CROE and decision support (DS) system--have on the growth rates of outpatient CT, MRI and ultrasound procedures over time. 

The CROE system was introduced in 2001 to assist physicians in making their decisions ordering high-cost imaging tests. The DS component was implemented three years later, providing physicians with a 1-9 appropriateness score--based on the existing American College of Radiology (ACR) Appropriateness Criteria, supplemented with locally developed indication and procedure pairs--for their diagnostic recommendation after clinical indications for the patient had been provided.

Based on a statistical analysis of data accumulated between October 2000 and December 2007, Sistrom and colleagues found that the implementation of the CROE and DS system led to a drastic decrease in high-cost imaging growth.  Although outpatient visits increased at a compound annual rate of nearly 5 percent during the course of the study, the annual outpatient CT growth rate decreased from 12 percent to 1 percent, while MRI and ultrasound annual growth rates each decreased by 5 percent, from 12 percent to 7 percent and 9 percent to 4 percent, respectively. 

“We believe that our results are attributable to two previously described effects of changes in the process for ordering diagnostic tests on procedure volumes,” the authors wrote. “The first is called the ‘gatekeeper effect,’ and it is simply due to the fact that a new (and sometimes more difficult) set of steps are required to order, schedule, or authorize the exam (e.g., our CROE system).

“In addition to the gatekeeper effect, a second phenomenon may come into play, and it can be called the ‘educational effect.’ This is limited to situations in which the new ordering process attempts to change practice patterns (as in our appropriateness DS rules) or at least provide some educational feedback.”

Ilyse Schuman, managing director of the Medical Imaging & Technology Alliance (MITA) hailed the study as an example of the benefit of ACR Appropriateness Criteria implementation for diagnostic imaging orders.

“This study provides groundbreaking evidence affirming that appropriateness criteria is the key to ensuring patients get the right scan at the right time,” said Schuman. It “confirms that the appropriateness criteria provisions in last year’s Medicare bill, and not pre-authorization requirements delivered by radiology benefit managers, are the right way for policymakers to ensure the proper use of advanced imaging equipment and generate savings without compromising access to life-saving diagnostic services.”