June 19, 2000 -- Want to find out when you're most fertile, whether you might have colon cancer, or might not be seeing as well as you should? Or wonder if your cholesterol level or blood sugar is too high? These are among the questions that can be answered with some of the newest home diagnostic tests.
But you may wonder whether these tests are really helpful: Do they provide reliable information that you can use to better manage your health, or do they only cause undue worry?
Some medical experts who looked at a few of the newer tests on the market say that yes, these tests can help -- as long as they're not used as a substitute for a doctor.
But before making health decisions based on these tests, he says, people should keep in mind that there may be factors of which they aren't aware. Patients should not use these tests in place of a doctor, he says, but integrate this information with what they get from their doctor.
"That's where they're going to get their best value," says Meza, vice chairman of clinical services in the department of family practice at Henry Ford Health System in Detroit.
A home diagnostic test also can cut down on waiting time for results. Unlike some tests done in a doctor's office, home tests often provide immediate answers.
But Meza cautions that the tests can be misinterpreted. Many people think test results always report either a definite yes or no. "That's not the case," he says. "There's something called false positives and false negatives. If you're at high risk for something, the screening test has more value. If you're at very low risk for something, you're probably going to have a false positive."
Kenneth Bollin, MD, chief of family practice at St. John Hospital in Detroit, tells WebMD that false positives and false negatives can often cause undue alarm. In a worst-case scenario, he says, they can lead to unnecessary or even potentially dangerous medical procedures.
"One of the problems with home testing is that the patient may take them as gospel truth," Bollin says.
At a recent conference on women's health in Hilton Head, S.C., Donnica L. Moore, MD, a health correspondent for NBCs Later Today, presented a "show-and-tell" of some of the newest home diagnostic tests.
One such test, ColoCare, makes it easy to check for blood in the feces, which may be an early sign of colon cancer. A card dropped in the toilet after a bowel movement will change color if blood is present, and can then be flushed away. According to the American Cancer Society, colon cancer has a near 90% cure rate when found early.
This type of test, Meza tells WebMD, is more prone than most to false positives and false negatives. He says he usually tells patients that such tests do not show whether or not they have cancer, only whether they should have further testing. He says this is a good test for people who have a higher likelihood of having a problem, such as those over age 50 or with a family history of colorectal cancer.
Another new test can help diabetics and others monitor levels of several substances in their blood.
"For years, diabetics have taken their own blood sugar [levels], but what I thought was pretty exciting was this device called the BioScanner 2000," Moore says.
Using a simple finger stick, patients place a drop of blood on a card that is then put into a monitor. The test can assess total glucose, total cholesterol, LDL or "bad cholesterol" levels, ketones, and triglycerides. Results can be stored in the unit, or sent via computer to the doctor's office. The FDA may approve a similar test that can show diabetics how well their disease has been controlled over several weeks.
That type of device should be used by someone who is managing a chronic disease such as diabetes or hyperlipidemia (high levels of fats in the blood), Meza says. It is not for a casual inquiry as to what last night's steak dinner did to your cholesterol levels; used that way, results can be misleading.
Some women who are having trouble conceiving a baby want to find out the time of the month they are most fertile, and there's another test that can help them. The Clear Plan Easy test is a palm-sized device that can help monitor menstrual cycles and assess days of peak fertility. Studies have shown that, among couples using this method, pregnancy occurs within two to three cycles, on average.
This test provides helpful information while preserving a couple's privacy, Meza says. As with the BioScanner, this information also can be sent to the doctor's office via computer link.
But not all the new tests are so high tech.
Moore says that a rather simple vision screening device from Visumetrics caught a vision problem she didn't know she had: an inability to detect contrast. The test, which involves simply looking at the card and answering some questions, can warn of the possibility of eye problems such as diabetic retinopathy, glaucoma, macular degeneration, or amblyopia. Moore, who has never worn glasses, says "I totally failed this test in one eye." She plans to follow up with her ophthalmologist.
Bollin, like Meza, emphasizes that all of these tests should be used in conjunction with a doctor's care. In fact, he suggests that people consult a physician before even buying home tests.
"Before using a home test, patients should check with their doctor to see if it would make sense for them," he says.