Doctors and their staffs sometimes fail to tell patients about abnormal test results, according to a report in the Archives of Internal Medicine.

Researchers from the Cornell Medical College reviewed records of more than 5,000 randomly selected patients. They found nearly 2,000 cases where there was an abnormal result.

Of those, there were 135 times that either the patient wasn't told or there was no record of the communication, about 7 percent of the time.

The team also found that most clinics don't follow the basic recommendations for setting up a process to make sure that doctors and patients know about test results.

The failure rates were highest in practices that use a mix of paper and electronic records, but they were about the same if a clinic used either all paper or all electronic.

In the study, researchers said that getting a handle on diagnostic and screening tests is important not only for patient health, but because diagnostic errors are the most frequent cause of malpractice claims in the U.S.