SELF-TESTING AND THE AMA: In my midnight post about Luddite journalists and Web logs, I compared them to investment advisors and do-it-yourself investing, since the former was the field I worked in before becoming a pixel-stained wretch. Ronald Bailey, writing in Reason magazine, notes another field that's circling the wagons at the guild (sorry to put my metaphors through the Cuisinart): doctors, who don't want their patients being able to self-test themselves.

The AMA’s claim that test results are too complex for laypeople is also simply outdated. There is an enormous amount of good medical information on the Internet that can provide background for people with health concerns and help them understand their lab results. But clients must keep firmly in mind that the retail testing labs do not offer diagnoses. If a test is anomalous, all the labs advise clients to visit their physicians immediately.

But what about false positives (a test that suggests a person has a problem when he or she doesn’t) or false negatives (a test that indicates a person is healthy when he or she is not)? "Any lab, including any that a doctor refers his patients to, can have false positives and negatives," says Vaughan. "That’s a risk that is just an inherent part of all medical testing."

A more troubling reason for the AMA’s opposition to retail testing labs is a desire to make sure that licensed medicos get a piece of the action. Doctors have traditionally served as testing gatekeepers. In order to get a test, a patient would first have to see a doctor -- who of course charges for the visit. Good for the doctor, not necessarily good for the patient. With doctors acting as testing gatekeepers, doctors may feel constrained to recommend only tests that are covered by a patient’s health insurance. Retail lab testing allows clients to take immediate advantage of the scores of new tests that are emerging from biotech research companies, instead of waiting for insurance companies to agree to cover them. Since clients generally pay for tests out-of-pocket, they can order whatever they want or need.