If you’re like most people, you’ve played the laboratory test waiting game, anticipating results that could tell if you have a serious illness or not. As if this wasn’t nerve wracking enough, federal regulators are now warning that results of laboratory developed tests may not be accurate.
What’s an LDT?
An LDT is a diagnostic laboratory test that a single medical testing laboratory has designed and used to check for certain medical issues. These run the gamut from the most common complete blood count, also called CBC, to complex multigene panels.
If you’re like me, you’ve probably never questioned the test results, but you may change your mind after reading about some of the issues the Federal Drug Administration has raised.
Issues With Self-Regulation
LDTs are not required to undergo premarket review for safety and competency, the way medical devices and drugs are. There is no premarket review — and adverse event reporting isn't required, either.
That said, a recent Federal Drug Administration study looked at 20 common LDTs used to detect serious medical conditions, including ovarian and breast cancer, coronary heart disease, whooping cough, Lyme disease, fibromyalgia and fetal chromosomal abnormalities.
The study identified some important gaps including the following three issues:
1) False-positive results
The 20 LDTs that were red-flagged can cause patients harm due to false-positive results — when patients were told they have conditions they do not really have — causing unnecessary concern and treatment.
2) False-negative results
There were a significant number of false-negative results from the cited LTDs, in which patients’ life-threatening diseases go undetected and, as a result, untreated.
3) Lack of connection to the actual medical condition