On the fallacy of accuracy

I could hardly not mention the so-called wrongful birth case of Deborah and Ariel Levy, the Oregan couple that is suing the doctor that carried out a CVS test for $14m after the test failed to detect that their daughter had Down’s syndrome.

As the Oregonian reports: “Had they known, they say, they would have terminated the pregnancy. Now they’re suing in Multnomah County Circuit Court, seeking more than $14 million to cover the costs of raising her and providing education, medical care, and speech and physical therapy for their daughter.”

Its easy to be outraged – Down’s Dad does a good job of summing up the initial reaction, but as Cate at I Don’t Know What to Say notes, it is somewhat understandable that the couple should look for someone to blame given that what we are told about the accuracy of diagnostic testing.

“I know I was told that a diagnostic test, like CVS, would provide an absolutely definitive answer. Which of course isn’t true, but who ever thinks they’ll be in that fraction of a percent, the margin of error?”

The fact is that “more than 99% accuracy” is not 100% accuracy but while the statistics are there for everyone to see many health care professionals, in my experience, talk about amnio and CVS testing as if it provides an absolutely definitive answer.

Whatever you think about the rights and wrongs of claiming $14m to care for your child, this case should remind everyone that when it comes to testing for Down’s syndrome, there is not such things as 100% accuracy.