Do It Yourself?

"It's as easy as 1, 2, 3." at least that's what's promised in the promotional material for a battery-powered blood-sugar monitor widely available in pharmacies. The device is one of the new wave of do-it-yourself home medical tests that will check everything from your blood pressure to your hiv status. In an age of managed care and skyrocketing doctor's fees, this niche market is rapidly growing into a multibillion-dollar industry. But before you fork over the cash for an "easy to use" kit, you had better take a look at the fine print.

That's the thrust of a report in last week's issue of Ergonomics in Design. It was prepared by researchers who took the trouble to test that "easy as 1, 2, 3" blood-sugar meter, which is supposed to let diabetes patients quickly check their blood-sugar levels. But what was advertised as a three-step process (prick your finger, squeeze a drop of blood on the test strip, wait for results) grew to 52 substeps by the time they got the thing working properly.

Even when the home tests work, the results can be misleading. Take, for example, the EZ Detect home colon-cancer-screening test. The packaging promises "a simple home test for detecting the early warning signs of colorectal disease." It's anything but. When customers open the $7.99 kit, they must make their way through a lengthy instruction sheet to learn the correct procedure for dropping a sequence of tissues into the toilet bowl to test for blood in the stool. The smallest error--such as leaving the tissue in the commode for an extra 30 seconds--can cause dramatically inaccurate results. In any event, blood in the stool is only one of many indicators of a developing cancer--and hardly the most definitive. No home colon-cancer test, no matter how easy, can replace a colonoscopy.

Other tests are both hard to use and unnecessary. Take, for example, those devices that measure body fat. Just hold the device like a steering wheel, one brand promises, and in a matter of seconds it will send an electrical pulse through your body and spit out your body-fat percentage. But the instruction booklet lists eight conditions--including swelling, pregnancy and even a cold or the flu--that will produce inaccurate results. Anyway, who besides competitive body builders really needs to keep such close tabs on body fat? The rest of us should be more concerned about the number that pops up on our bathroom scale.

Not all home tests are bad, of course. Some, like home pregnancy kits, can be useful. The FDA has approved several new tests, including the Home Access HIV Test Kit ($54.95) and the Hepatitis C Check ($69.95), designed to reach a whole market of people who for various reasons don't want to be tested in a doctor's office. A special coding system allows you to send your blood sample to a laboratory anonymously and get the results in a few business days. These tests are controversial, however, because someone who, for example, tests positive for HIV will need immediate medical attention and counseling. In the end, there is no substitute for seeing a doctor. But if you do decide to use a home test, make sure it's FDA approved and that you check the results with your physician.

Dr. Ian is a medical correspondent for NBC's Today show. E-mail: ianmedical@aol.com