A chest X-ray

A chest X-ray (Associated Press)

Doctors who have access to computer test results order more tests than doctors who don’t, according to a new study that challenges an assumption about electronic health records.

The study in the March issue of the journal Health Affairs found that doctors with access to computerized images ordered 40 to 70 percent more imaging and lab tests.

The study authors warn that pushing for more health information technology might not deliver cost savings from reductions in duplicative or inappropriate tests and could drive up costs.

“Our findings should at a minimum raise questions about the whole idea that computerization decreases test ordering and therefore costs in the real world of outpatient practice,” lead author Danny McCormick, a physician and assistant professor of medicine at Harvard Medical School, said in a statement. “As with many other things, if you make things easier to do, people will do them more often.”

McCormick and his colleagues looked at data from the 2008 National Ambulatory Medical Care Survey, including almost 29,000 patient visits to almost 1,200 physician offices.

They found doctors with access to electronic imaging, sometimes through electronic health records, ordered imaging in 18 percent of visits while those without the electronic systems ordered imaging in 12.9 percent of visits.

Women got more images that men overall but not more advanced images. This could reflect the use of mammograms and ultrasounds. And surgeons and specialists were more likely to order images than primary care doctors.

Past studies have estimated that electronic systems would save as much as $8.3 billion a year on imaging and lab testing. The study authors say this likely reflects institutions with new, cutting-edge systems rather than general existing systems in existing offices. These older systems can be cumbersome, insufficiently interoperable and lacking in decision support.

The authors said they were not criticizing electronic investments. But they more of an impact would come from curbing doctors who refer patients to imaging facilities in which they have a financial stake.