Lab results sent directly to doctors' computer screens sometimes get lost in a flood of other alerts, according to a new study.

Researchers, who surveyed over 2,500 doctors at U.S. veterans hospitals, found that doctors received several dozen electronic alerts every day, and nearly a third said they've missed lab results and that ended up delaying their patients' care.You can easily miss one or two, because the signal gets buried," said Dr. Hardeep Singh, the study's lead author from the Houston VA Health Services Research and Development Center of Excellence.

For the new study, Singh and his colleagues used surveys sent to about 5,000 doctors who used electronic health records (EHR) within the U.S. Department of Veterans Affairs, from June through November 2010.Of the 2,590 who responded, the researchers found the doctors received an average of about 63 alerts through the EHR system every day. Those alerts include results from blood tests and radiology exams.

Almost 90 percent thought the number of alerts they got was excessive, and about 70 percent said they get more alerts than they can "effectively manage."More than half of the doctors said it was possible to miss results using the current EHR system, and about 30 percent said they had missed lab results that led to their patients' care being delayed.

The findings show that doctors who use EHR systems are vulnerable to information overload, the researchers write in JAMA Internal Medicine. But, they caution, they cannot prove that using the electronic records is what caused the doctors to miss lab results."This is true for both paper based settings… and electronic health record systems. In fact, I think the electronic health record systems make it better, but I think we've realized there are challenges along the way," Singh said.

Previous research has shown both advantages and disadvantages in using EHR systems.Last March, researchers found that doctors order fewer tests when they have access to their patient's EHR, and another study published earlier this year found the computer-based systems allow doctors to transfer out-of-date information between files.Singh told Reuters Health there are a few steps that may help ensure doctors see all lab results.

Those include training doctors to use the electronic system's settings to weed out unimportant alerts, giving doctors more time to go through results and making sure there is someone responsible for following up every time a test is performed on a patient.Dr. Alexander Turchin, who studies EHR systems but was not involved in the new research, also said it's possible to design EHR systems in which errors are much less common.

"I think we do need to continue working on financing the systems further and improving the systems. Even if harm is rare, it should be rarer still," said Turchin, from Boston's Brigham and Women's Hospital.Singh added that patients should also feel comfortable asking for their test results - instead of assuming doctors only call with abnormal results."One thing we're trying to dispel in research is the myth of ‘no news is good news,'" he added.