Providers at Johns Hopkins Hospital ordered about 9 percent fewer lab tests when their computerized records system displayed prices. (JAMA INTERNAL MEDICINE)

Doctors may order fewer laboratory tests during a patient’s hospital stay if they know how much the tests cost, a new study suggests.

Researchers found that health-care providers at Johns Hopkins Hospital ordered about 9 percent fewer lab tests, such as blood work, when their computerized records system displayed the price.

Before the study, “we saw a lot of waste. We saw a lot of tests that didn’t need to be ordered,” said Leonard Feldman, an assistant professor of medicine at the Johns Hopkins University School of Medicine and the study’s lead author.

Part of the reason doctors order a lot of tests might be that they don’t know how expensive they are, according to the researchers.

It is estimated that the U.S. health-care system wasted about $226 billion on overtreatment and unnecessary use of lab tests during 2011, Feldman and his colleagues wrote in the journal JAMA Internal Medicine last week.

Unnecessary tests can also put patients at risk of being harmed by additional screenings or procedures if the first comes back with a false positive.

“The rational approach to ordering tests is something we should all be interested in, and something — if we did better — that would save the system money and save the patients the horror of causing harm,” Feldman said.

For the study, the researchers compiled a list of some of the most common and most expensive lab tests ordered at the hospital. From November 2009 to May 2010, they had the hospital’s record system display the cost of half of those tests.

Doctors didn’t know why the prices were being displayed. If they asked, they were told only that it was part of a research project.

Looking only at the tests whose prices were displayed, Feldman’s team found that doctors and other hospital staff members ordered an average of 3.4 tests per hospitalized patient per day. That compared with 3.7 tests per day in the year before the prices were shown.

That reduction was slightly offset by a small increase in tests whose prices were not displayed, compared with the prior year. Feldman said that this increase can be partially explained by doctors’ switching from more comprehensive blood tests, which were included in the price list, to simpler blood tests whose prices were not shown.

Over all, the researchers found that the cutback on tests saved the health system more than $400,000 during the study period, compared with spending before the prices were listed.

William Tierney, of the Indiana University School of Medicine in Indianapolis, who wrote an editorial accompanying the new study, said it’s not known whether the doctors began ordering tests more appropriately or if they were forgoing tests the patients actually needed.

Minal Kale, from the Icahn School of Medicine at Mount Sinai in New York, said the study shows that doctors will change their behavior if they see a test’s price.

“I think it’s definitely something to consider,” said Kale, who was not involved in the study. “It definitely could be a part of an approach to decrease overuse,” she added.

— Reuters