Doctors order fewer laboratory tests during a patient's hospital stay if they know how much the tests cost, according to a new study.
Researchers found that doctors at one U.S. 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 Dr. Leonard Feldman, the study's lead author from The Johns Hopkins University School of Medicine in Baltimore.
Part of the reason doctors order a lot of tests could be that they don't know how expensive they are, according to the researchers.
It's estimated that the U.S. healthcare system wasted about $226 billion on overtreatment and unnecessary use of lab tests during 2011, Feldman and his colleagues wrote in JAMA Internal Medicine on Monday.
As well as adding cost, unnecessary tests can 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 new study, the researchers compiled a list of some of the most common and most expensive lab tests ordered at The Johns Hopkins 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 started being displayed. They were only told that it was part of a research project if they asked.
Feldman's team found doctors ordered an average of 3.4 lab tests per hospitalized patient per day with prices displayed during those six months. That compared to 3.7 tests per day before the prices were shown between 2008 and 2009.
That reduction was slightly offset by a small uptick in the number of tests ordered from the list without prices, compared to the prior year.
Feldman told Reuters Health that increase can be partially explained by doctors switching from more comprehensive blood tests, which were included in the price list, to simpler blood tests that did not have a price shown.
All in all, the researchers found doctors saved the health system over $400,000 by not ordering certain tests during the study period, compared to before the prices were listed.
However, Dr. William Tierney, who wrote an editorial accompanying the new study, told Reuters Health it's not known whether the doctors were ordering tests more appropriately - or if they were forgoing tests the patients actually needed.
"You just can't tell without that data from that health system," said Tierney, from the Regenstrief Institute and the Indiana University School of Medicine in Indianapolis.
Dr. Minal Kale, from the Icahn School of Medicine at Mount Sinai in New York, said the study isn't entirely positive, but it shows doctors will change their behaviors if they see a test's price.
"I think it's definitely something to consider," said Kale, who has studied healthcare use but was not involved in the new study.
"It definitely could be a part of an approach to decrease overuse… It could be one approach among many that need to occur," she added.