The FDA regulates in vitro diagnostic devices (IVDs) as medical devices. IVDs analyze human samples, such as blood, saliva, tissue and urine. However, in the past, the agency did not use its authority to regulate what are known as “laboratory-developed tests” (LDTs), tests developed and performed at a single laboratory, with all samples sent to that particular lab for testing. Instead, it focused on commercial tests kits, which are broadly marketed to laboratories or the public. These tests had to undergo the same pre-market approval process as other medical devices regulated by the FDA, including, in some cases, clinical studies demonstrating that the device is safe and effective for its intended use.
Historically, LDTs were developed by hospitals, researchers and academic medical centers for their own use. That is no longer true. In the past 15 years or so, there has been an explosion in the use of LDTs by commercial labs and biotechnology companies. The FDA now estimates that there are about 11,000 LDTs offered by 2,000 laboratories. One estimate is that the results of clinical lab tests (although not exclusively LDTs) influence 70% of health care decisions. (See the Congressional Research Service Report’s exhaustive analysis of FDA regulation of IVDs and inclusion of LDTs for more on the history and current use of LDTs.)
Do you have any idea whether the IVDs that have poked around in your blood or tissues are FDA-approved or unapproved LDTs? (Does your physician?) Do you know what evidence (if any) there is standing behind these tests? No? Me either. That’s because there is no requirement that anyone give you this information. (more…)