The benefits of reduced imaging from the use of health information exchange have largely been the stuff of anecdote and theory, until now.

In one of the first large-scale empirical studies on the links between HIE participation and imaging in hospital emergency departments, researchers from Mathematica Policy and the University of Michigan found redundant CT scans, X-rays and ultrasounds decreased fairly significantly — with savings in the millions of dollars.

Mathematica researcher Eric Lammers and colleagues compared the rates of repeat CT scans, chest x-rays and ultrasounds at 37 EDs connected to an HIE to the rates at 410 EDs not connected to an HIE in California and Florida between 2007 and 2010. The team used the state emergency department database and HIMSS Analytics’ listing of hospital HIE participation, and defined repeat images as those given to patients for examining the same region of the body and performed within 30 days at unaffiliated emergency departments.

They found that hospital EDs participating in an HIE had reduced imaging in all of the modalities, compared to those without an HIE link. On average EDs using an HIE were 8.7 percent less likely to repeat CT scans, 9 percent less likely to repeat ultrasounds and 13 percent less likely to repeat chest X-rays.

[See also: New imaging rules set for safety's sake.]

The study, published in the journal Medical Care, concluded that if all of the hospital EDs in California and Florida were participating in HIEs, the two states could save about $3 million annually by avoiding repeats of those three imaging modalities. Applying the results nationally, $19 million could be saved from avoided repeats of those images if every ED participated in an HIE.

Now, those estimated cost savings “are small relative to the annual healthcare expenditures in the United States,” some $2.8 trillion at last count, Lammers and colleagues wrote. “Nevertheless, these findings bolster the rationale behind federal policy efforts to achieve nationwide HIE."Plus there is the reduced radiation exposure for patients in the case of CT scans and x-rays.

The study also found some other data suggesting that HIE could pick up slack: Repeat tests are more likely to be done in large emergency departments.

“We speculate that this may be attributable to a cultural preference for more intensive use of medical technology in larger EDs, easier access to imaging (eg, CT scanners physically located in the ED itself), or perhaps greater stress on staff resources in EDs that see more patients, thus leading to more intensive reliance on diagnostic technology,” Lammers and colleagues wrote. “In any event, this suggests there may be unique challenges that must be overcome to realize the greater potential reduction of repeat testing from HIE in these settings.”

The study gives HIEs more evidence to support their value proposition, which is “particularly critical to enabling HIE efforts to identify a sustainable business model, a primary obstacle to their success,” the researchers wrote.

[See also: Imaging use in steady decline.]

The study should also allay some concerns among payers that HIEs can’t help control imaging duplication, while motivating providers, they argued, “particularly as the country moves toward global payments for episodes of care, which will invoke strong incentives for reducing redundant imaging."