According to a recent article in Scientific American, not all lab tests are equally reliable, and faulty ones can have serious consequences. Lab-developed tests, or LDTs, are defined as tests that are manufactured and interpreted by the same individual lab that designed them. According to the article, "some experts believe many of these tests are not useful, and some may even cause harm by convincing too many people that they have a rare illness when they do not, diagnosing them with a condition that has so far not been shown to be harmful or reassuring them that they are healthy when in fact there is no scientifically credible way to know if that is indeed the case."
Under current federal regulations, LDTs do not have to be evaluated for their medical usefulness. Nor are they required to have research about them made public. However, in 2014, the U.S. Food and Drug Administration (FDA) released proposed guidelines that will subject the measures, for the first time, to federal oversight—including having to submit evidence of efficacy to it before the tests may be marketed.
Because the FDA does not have the resources to oversee all the LDTs, the agency plans to divide them into three categories, based on the likelihood that a misleading or incorrect result from a particular test could cause substantial harm. Under the new guidelines, LDTs would be considered high risk if inaccurate results could lead to death or prolonged disabilities.
However, this approach worries many industry leaders and some professional medical societies, including the American Medical Association. According to Curtis Hanson, M.D., chief medical officer at Mayo Medical Laboratories in Rochester, Minn., which conducts 25 million lab tests per year, “It really depends on how the FDA chooses to define high risk, and that currently isn't clear. High-risk tests could amount to between 1 and 10 percent of LDTs on the market today. How is the FDA going to review and find the rare cases where you have problems and do that in an efficient way that doesn't slow progress?”