Yesterday's New York Times had a special section -- a "user's guide" -- on diagnostic testing. It covers asthma, bone disease, cancer, heart disease, obesity, diabetes, AIDS and glaucoma. Don't have time to read it? Here's what you need to know. The section on asthma says there's still no gold-standard test. "There are no easy markers or a single blood test to tell when it’s asthma and when it’s not," a family-practice physician tells the Times, which notes that unlike for many other conditions, with asthma, "doctors often rely more on family histories and thorough questioning about symptoms and exposure to allergens." The article mentions spirometers, for measuring airway efficiency, as the best currently available technology. The EasyOne spirometer is featured in full-color (with no mention of its maker, ndd Medical Technologies). The piece on bone disease tackles the debate surrounding diagnostic arthroscopies. One camp says they help avoid unnecessary drastic procedures like hip relacements while the other says conventional screening (i.e., MRI and x-ray) should always come first. The Times doesn't mention any specific firms working in the field, but if you go here and type "arthroscopy" in the keyword search, you'll find a few. The cancer section focuses on colon cancer, and specifically, people's discomfort with getting checked for it. The article runs through the different kinds of available tests -- fecal occult blood test, sigmoidoscopy, barium enema/x-ray, and of course colonoscopy -- and also mentions virtual colonoscopy as a more pleasant option because it doesn't require sedation and is performed using a CT scan. It warns, though, "The virtual test is being heavily marketed by some clinics, but the American Cancer Society and other groups are not recommending it yet, saying it needs more study." Again, no mention of manufacturers. Viatronix, of Stony Brook, NY, is one maker of virtual colonoscopy machines. And E-Z-EM, of Lake Success, NY, makes accompaniment products for the procedure. The consensus, according to the Times, on heart disease, is that no one knows how much or what kind of testing to perform. It's generally agreed upon that diet and exercise should come first, but then what? The article points to the United States Preventive Services Task Force, which is of the philosophy that more tests aren't always better, that people should take only basic tests. "The concern is that seemingly innocuous tests will give false-positive results, which lead to more tests and even treatments, when there was nothing wrong to begin with," says the article. With concerns about the safety of statins running high, though, many patients want their heart-disease risk verified before going on a drug. Testing for elevated blood-protein levels and performing heart scans are two detection methods mentioned. Obesity is a tough one too, according to the special section. Waist and body mass index (BMI) measurements have been the standard for a while, but they don't always give an accurate assessment of whether someone is truly obese. A doctor interviewed for the article says she also likes to screen for metabolic conditions. Microlife, whose corporate headquarters are in Dunedin, FL, is one company in this space. It makes devices for monitoring metabolic rates, as well as weight management and nutrition monitoring software. At last, in the diabetes section, a manufacturer finally gets some props. After talking about blood sugar tests and glucose tolerance tests, the article mentions a new genetic test, introduced last month, to identify people who are at risk for developing Type 2 diabetes. "The $500 test by DeCode Genetics cannot predict diabetes definitively," says the piece, "but it might motivate people with a high risk to exercise and lose weight." Yay! More on deCODE (the company's preferred way of writing it), an Icelandic firm, here. The section on AIDS doesn't say much, other than to mention that CDC now recommends HIV testing be part of routine healthcare for everyone, not just at-risk groups. Medford, NY-based Chembio is big in this space. The company has two FDA-approved rapid HIV tests, both of which are marketed by Inverness Medical. Chembio was recently awarded a U.S. patent for its Dual Path Platform (DPP) technology, thought to offer considerable advantages over today’s single path tests. As part of its deal with Chembio, Inverness has dibs on any future HIV tests developed with DPP. Glaucoma, so the Times says, has a similar problem to heart disease's: to test or not to test? The United States Preventive Services Task Force, for one, thinks early screening for everyone is excessive. The article says the task force believes "there are no studies establishing the effectiveness of screening and that the uncertainty of the benefit and the known risks of early treatment make it impossible to determine whether there is any advantage in screening the general population." Others think waiting too long to test for glaucoma can cause vision loss that could have been prevented if treatment was provided earlier. The Times says the controversy stems from the fact that glaucoma is tricky to diagnosis. For a list of companies working to crack the code, type "glaucoma" into the keyword search here.