Monitoring hemoglobin A1c is the gold standard method for tracking blood sugar levels in diabetics. Many patients don't get the test nearly as often as experts advise, perhaps because it has required a trip to the lab and another medical bill.

But a new device, available without prescription and approved last month by the Food and Drug Administration (FDA), can provide fast A1c readings at home. Still, some experts questioned the need for and value of a home test for A1c.

The wisdom of tracking A1c levels has been acknowledged since a landmark clinical trial, completed in 1993, showed that small reductions in blood levels of this protein -- whose presence can serve as a measure of blood sugar over a three- to four-month period -- can lead to significant reductions in the risk of serious complications such as blindness and kidney disease.

In recommendations released this month, the American Diabetes Association (ADA) said that diabetics should get A1c screenings about once every three months. Guidelines from the American College of Endocrinology and the American Association of Clinical Endocrinologists are similar.

But Metrika, the Sunnyvale, Calif., company that makes the home monitor, called A1cNow, estimates that three-quarters of type 2 diabetics don't know their A1c level.

To use the new device, patients use a finger prick to collect a small blood sample, diluting it in a tube of solution and then putting the mixture in the device. A digital display gives the reading in minutes.

The ADA says well-controlled diabetics should have A1c readings of 6.5 percent or less. Non-diabetics have A1c levels of between 4 percent and 6 percent. Metrika said studies submitted to the FDA showed the home test to be 98 percent as accurate as laboratory tests.

A1cNow costs about $25, less than the cost of a typical lab test for this protein, according to Michael Allen, Metrika's chief executive. But while Medicare will pay for the A1c test when used in a health care setting, the government insurer won't yet pay for home testing. Allen says it's too early to know if any private insurers will cover it.

But Helena Rodbard, an endocrinologist in private practice in Rockville and Bestheda and past president of the American College of Endocrinology, said she isn't convinced A1cNow will prove valuable.

"I don't really think it has a role in the patient's self-management," she said, emphasizing the importance of doctor visits. "It's a very important test and patients should really not be doing that themselves."

-- Brian Reid

But not all experts think A1c readings should be done at home.