Electronic health records — touted by policymakers as a way to improve the quality of health care — failed to boost care delivered in routine doctor visits, U.S. researchers said on Monday.

Of 17 measures of quality assessed, electronic health records made no difference in 14 measures, according to a study published in the Archives of Internal Medicine.

The study by researchers at Stanford and Harvard Universities was based on a survey of 1.8 billion physician visits in 2003 and 2004. Electronic health records were used in 18 percent of them.

In two areas, better quality was associated with electronic records, while worse quality was found in one area, they said.

Many experts believe electronic records can help prevent costly medical mistakes, but few studies have evaluated whether the records actually improve the level of care when compared with paper records.

"Our findings were a bit of a surprise. We did expect practices (with electronic medical records) would have better quality of care," said Dr. Randall Stafford of Stanford University. "They really performed about the same," he said in a telephone interview.

The 14 quality indicators for which electronic records made no significant difference included such factors as prescribing recommended antibiotics; diet and exercise counseling for high-risk adults; screening tests; and avoiding potentially inappropriate prescriptions for elderly patients.

The records seemed to help doctors treating patients with depression to avoid prescribing certain tranquilizers. They also helped to avoid offering urinalysis during general medical exams.

But when it came to prescribing statins for patients with high cholesterol, physicians using electronic systems did worse than their peers with paper records.

Electronic health records promise to eliminate errors due to bad handwriting and make it easier for doctors to follow a patient’s care over time.

Some systems can also flag dangerous drug combinations, or offer advice about tests or drugs the doctor might prescribe.

President George W. Bush has set a goal for all Americans to have electronic medical records by 2014.

"I think they will be a very important tool, but I think they are not sufficient in and of themselves to improve quality a great deal," Stafford said.